WorldWideScience

Sample records for composite resins

  1. Foam, Foam-resin composite and method of making a foam-resin composite

    Science.gov (United States)

    Cranston, John A. (Inventor); MacArthur, Doug E. (Inventor)

    1995-01-01

    This invention relates to a foam, a foam-resin composite and a method of making foam-resin composites. The foam set forth in this invention comprises a urethane modified polyisocyanurate derived from an aromatic amino polyol and a polyether polyol. In addition to the polyisocyanurate foam, the composite of this invention further contains a resin layer, wherein the resin may be epoxy, bismaleimide, or phenolic resin. Such resins generally require cure or post-cure temperatures of at least 350.degree. F.

  2. Resin composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Lussi, Adrian

    2014-01-01

    OBJECTIVE: To investigate how the modulus of elasticity of resin composites influences marginal quality in restorations submitted to thermocyclic and mechanical loading. METHODS: Charisma, Filtek Supreme XTE and Grandio were selected as they were found to possess different moduli of elasticity...... of resin composite (p=0.81) on the quality of dentine margins was observed, before or after loading. Deterioration of all margins was evident after loading (p....008). CONCLUSIONS: The resin composite with the highest modulus of elasticity resulted in the highest number of gap-free enamel margins but with an increased incidence of paramarginal enamel fractures. CLINICAL SIGNIFICANCE: The results from this study suggest that the marginal quality of restorations can...

  3. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  4. Resin impregnation process for producing a resin-fiber composite

    Science.gov (United States)

    Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

    1994-01-01

    Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

  5. Measurement of opalescence of resin composites.

    Science.gov (United States)

    Lee, Yong-Keun; Lu, Huan; Powers, John M

    2005-11-01

    Opalescence is an optical property, where there is light scattering of the shorter wavelengths of the visible spectrum, giving the material a bluish appearance under reflected light and an orange/brown appearance under transmitted light. The objective of this study was to determine the opalescence of resin composites with a color measuring spectrophotometer. Colors of A2 and enamel or translucent shades of four resin composites and of an unfilled resin measured in the reflectance and transmittance modes were compared, and the opalescence parameter (OP) was calculated as the difference in blue-yellow coordinate (Deltab*) and red-green parameter (Deltaa*) between the reflected and transmitted colors of 1-mm thick specimens. The masking effect was calculated as the color difference between the color of a black background and the color of specimen over the black background. The range of OP in resin composites was 5.7-23.7, which was higher than that of the unfilled resin. However, there were significant differences among the brands and shades of the resin composites. Opalescence varied by brand and shade of the resin composites, and contributed to the masking of background color along with translucency parameter. Some of the resin composites actually displayed opalescence.

  6. Microhardness of resin composite materials light-cured through fiber reinforced composite.

    NARCIS (Netherlands)

    Fennis, W.M.M.; Ray, N.J.; Creugers, N.H.J.; Kreulen, C.M.

    2009-01-01

    OBJECTIVES: To compare polymerization efficiency of resin composite basing materials when light-cured through resin composite and fiber reinforced composite (FRC) by testing microhardness. METHODS: Simulated indirect restorations were prepared by application of resin composite (Clearfil AP-X) or FRC

  7. Fiber reinforced silicon-containing arylacetylene resin composites

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available A silicon-containing arylacetylene resin (SAR, a poly(dimethylsilyleneethynylene phenyleneethynylene (PMSEPE, was synthesized. The PMSEPE is a solid resin at ambient temperature with a softening temperature about 60°C and soluble in some solvents like tetrahydrofuran. The melt viscosity of the PMSEPE resin is less than 1 Pa•s. The resin could cure at the temperature of lower than 200°C. Fiber reinforced PMSEPE composites were prepared from prepregs which were made by the impregnation of fibers in PMSEPE resin solution. The composites exhibit good mechanical properties at room temperature and 250°C. The observation on fracture surfaces of the composites reinforced by glass fibers and carbon fibers demonstrates that the adhesion between the fibers and resin is good. The results from an oxyacetylene flame test show that the composites have good ablation performance and XRD analyses indicate that SiC forms in the residues during the ablation of the composites.

  8. Ballistic properties of bidirectional fiber/resin composites

    International Nuclear Information System (INIS)

    Dimeski, Dimko; Spaseska, Dijana

    2004-01-01

    The aim of the research was to make evaluation of the ballistic strength of four different fiber/resin composites intended to be used in manufacturing of ballistic items for personal protection. Research has been performed on glass, ballistic nylon, aramid and HPPE (High Performance Polyethylene) plainly woven fabric based composites. As a matrix system, in all cases, polyvinylbutyral modified phenolic resin was used. For the investigation, areal weight range 2 - 9 kg/m 2 chosen was, which is applicable for personal ballistic protection and the ultimate resin content range 20 - 50 vol.%. Ballistic test of the composites has shown that the best results exhibit HPPE based composites; aramid based composites have been the second best followed by the polyamide based composites. The worst results have been shown by the glass based composites. All composites with lower resin content (20%) have performed much better than their counterparts with higher resin content (50 %).The plot of the ballistic strength (V 50 ) versus areal weight has shown a linear increase of V 50 with the increase of areal weight. The ballistic strength of the composites is highly dependant on the fiber/resin ratio and increases with the increase of the fiber content. (Author)

  9. Bisphenol A Release: Survey of the Composition of Dental Composite Resins.

    Science.gov (United States)

    Dursun, Elisabeth; Fron-Chabouis, Hélène; Attal, Jean-Pierre; Raskin, Anne

    2016-01-01

    Bisphenol A (BPA) is an endocrine disruptor with potential toxicity. Composite resins may not contain pure BPA, but its derivatives are widely used. Several studies found doses of BPA or its derivatives in saliva or urine of patients after composite resin placement. The aims of this study were to establish an exhaustive list of composite resins marketed in Europe and their composition, and to assess the extent of BPA derivatives used. A research on manufacturers' websites was performed to reference all composite resins marketed in Europe, then their composition was determined from both material safety data sheets and a standardized questionnaire sent to manufacturers. Manufacturers had to indicate whether their product contained the monomers listed, add other monomers if necessary, or indicate "not disclosed". 160 composite resins were identified from 31 manufacturers and 23 manufacturers (74.2%) responded to the survey. From the survey and websites, the composition of 130 composite resins (81.2%) was: 112 (86.2%) based on BPA derivatives, 97 (74.7%) on bis-GMA, 17 (13.1%) without monomer derived from BPA (UDMA, sometimes with TEGDMA) and 6 (4.6%) with UDMA (only); 1 (0.8%) did not contain a BPA derivative or UDMA or TEGDMA. Pure BPA was never reported. This work has established a list of 18 composite resins that contain no BPA derivative. Manufacturers should be required to report the exact composition of their products as it often remains unclear or incomplete.

  10. Volumetric polymerization shrinkage of contemporary composite resins

    Directory of Open Access Journals (Sweden)

    Halim Nagem Filho

    2007-10-01

    Full Text Available The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (a or = 0.05 was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01 and Definite (1.89±0.01 shrank significantly less than the other composite resins. SureFil (2.01±0.06, Filtek Z250 (1.99±0.03, and Fill Magic (2.02±0.02 presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation.

  11. Color of bulk-fill composite resin restorative materials.

    Science.gov (United States)

    Barutcigil, Çağatay; Barutcigil, Kubilay; Özarslan, Mehmet Mustafa; Dündar, Ayşe; Yilmaz, Burak

    2018-03-01

    To evaluate the color stability of novel bulk-fill composite resins. Color measurements of a nanohybrid composite resin (Z550) and 3 bulk-fill composite resins (BLK, AFX, XTF; n = 45) were performed before polymerization. After polymerization, color measurements were repeated and specimens were immersed in distilled water or red wine, or coffee. Color change [CIEDE2000 (ΔE 00 )] was calculated after 24 h, 1 and 3 weeks. Data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests (α = 0.05). Color changes observed after polymerization were significant for all groups. Color changes observed in distilled water for Z550 and AFX were significant. Color changes after stored in red wine and coffee were significant for all groups. Bulk-fill composite resin color change increased over time for all groups in red wine and coffee (P composite resin and bulk-fill composite resins. AFX had the highest color change in distilled water. The color of tested bulk-fill composite resins significantly changed after immersion in beverages and over time. Color change observed with the nanohybrid composite resin after 1 week was stable. Clinicians should keep in mind that tested composite resins may change color when exposed to water and significantly change color immediately after they are polymerized. In addition, the color change continues over time should the patient is a coffee and/or red wine consumer. © 2017 Wiley Periodicals, Inc.

  12. Surface roughness of etched composite resin in light of composite repair

    NARCIS (Netherlands)

    Loomans, B.A.C.; Cardoso, M.V.; Opdam, N.J.M.; Roeters, F.J.M.; Munck, J. De; Huysmans, M.C.D.N.J.M.; Meerbeek, B. Van

    2011-01-01

    OBJECTIVES: In search for clinically effective composite repair protocols, the effect of various etching protocols on the surface roughness of composite resins with different filler composition were investigated. METHODS: Of two composite resins (hybrid-filled Clearfil AP-X; nano-filled Filtek

  13. Volumetric polymerization shrinkage of contemporary composite resins

    OpenAIRE

    Nagem Filho, Halim; Nagem, Haline Drumond; Francisconi, Paulo Afonso Silveira; Franco, Eduardo Batista; Mondelli, Rafael Francisco Lia; Coutinho, Kennedy Queiroz

    2007-01-01

    The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill ...

  14. Thermal cycling effects on adhesion of resin-bovine enamel junction among different composite resins.

    Science.gov (United States)

    Chen, Wen-Cheng; Ko, Chia-Ling; Wu, Hui-Yu; Lai, Pei-Ling; Shih, Chi-Jen

    2014-10-01

    Thermal cycling is used to mimic the changes in oral cavity temperature experienced by composite resins when used clinically. The purpose of this study is to assess the thermal cycling effects of in-house produced composite resin on bonding strength. The dicalcium phosphate anhydrous filler surfaces are modified using nanocrystals and silanization (w/NP/Si). The resin is compared with commercially available composite resins Filtek Z250, Z350, and glass ionomer restorative material GIC Fuji-II LC (control). Different composite resins were filled into the dental enamel of bovine teeth. The bond force and resin-enamel junction graphical structures of the samples were determined after thermal cycling between 5 and 55°C in deionized water for 600 cycles. After thermal cycling, the w/NP/Si 30wt%, 50wt% and Filtek Z250, Z350 groups showed higher shear forces than glass ionomer GIC, and w/NP/Si 50wt% had the highest shear force. Through SEM observations, more of the fillings with w/NP/Si 30wt% and w/NP/Si 50wt% groups flowed into the enamel tubule, forming closed tubules with the composite resins. The push-out force is proportional to the resin flow depth and uniformity. The push-out tubule pore and resin shear pattern is the most uniform and consistent in the w/NP/Si 50wt% group. Accordingly, this developed composite resin maintains great mechanical properties after thermal cycling. Thus, it has the potential to be used in a clinical setting when restoring non-carious cervical lesions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Comparison of Mechanical Properties of Resin Composites with Resin Modified Glass Ionomers

    Directory of Open Access Journals (Sweden)

    Taha NA

    2015-06-01

    Full Text Available Statement of Problem: There are controversial reports regarding physical and mechanical properties of resin composites and glass ionomer cements. Some revealed higher strength and hardness for resin composites while others showed a comparable value for glass ionomer cements. Evaluation of mechanical properties of different types of resin composites in comparison with resin modified glass ionomers is not widely studied. Objectives: To measure and compare the flexural strength and Vickers hardness of three resin composites and two resins modified glass ionomer cements before and after ageing. Materials and Methods: Three resin composites, i.e. Filtek Supreme XTE (3M ESPE, Ice (SDI, Gradia (GC, and two resins modified glass ionomers, i.e. Fuji II LC (GC and Riva Light Cure (SDI, were selected. Ten barshaped specimens were prepared for each material and cured using LED curing light. After 24 hours storage in distilled water at 37oC, the specimens were randomly divided into two equal groups (n=5. The first group was tested as a baseline and the second group was restored at 37oC for another 29 days. Flexural strength was performed by four-point bending test using universal testing machine at crosshead speed of 0.5mm/min, and the maximum load at failure was recorded. The specimen’s halves were used for evaluating Vickers hardness, using a Digital Hardness Tester (300 g/15 sec and the Vickers hardness number (VHN was recorded. Data were analyzed using one-way analysis of variance (ANOVA, Tukey’s and student’s t-test. Results: After 24 hours of immersion, the highest hardness number was found for Filtek Supreme and Ice and the highest flexural strength was obtained for Gradia. After 30 days of storage, hardness of Fuji II LC and Gradia showed a significant decrease; flexural strength of Ice and Fuji II LC revealed a significant increase while Gradia and Filtek Supreme showed a significant decrease. Conclusions: Resin modified glass ionomers showed

  16. SEM and elemental analysis of composite resins

    International Nuclear Information System (INIS)

    Hosoda, H.; Yamada, T.; Inokoshi, S.

    1990-01-01

    Twenty-four chemically cured, 21 light-cured anterior, three light-cured anterior/posterior, and 18 light-cured posterior composite resins were examined using scanning electron microscopy, and the elemental composition of their filler particles was analyzed with an energy dispersive electron probe microanalyzer. According to the results obtained, the composite resins were divided into five groups (traditional, microfilled type, submicrofilled type, hybrid type, and semihybrid), with two additional hypothetical categories (microfilled and hybrid). Characteristics of each type were described with clinical indications for selective guidance of respective composite resins for clinical use

  17. Posterior bulk-filled resin composite restorations.

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2016-01-01

    up to 4mm as needed to fill the cavity 2mm short of the occlusal cavosurface. The occlusal part was completed with the nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2mm increments. The restorations were evaluated using...... Class II, 4 SDR-CeramX mono+ and 6 CeramXmono+-only restorations. The main reasons for failurewere tooth fracture (6) and secondary caries (4). The annual failure rate (AFR) for all restorations (Class I and II) was for the bulk-filled-1.1% and for the resin composite-only restorations 1...

  18. Correlations of norbornenyl crosslinked polyimide resin structures with resin thermo-oxidative stability, resin glass transition temperature and composite initial mechanical properties

    Science.gov (United States)

    Alston, William B.

    1988-01-01

    PMR (polymerization of monomeric reactants) methodology was used to prepare 70 different polyimide oligomeric resins and 30 different unidirectional graphite fiber/polyimide composites. Monomeric composition as well as chain length between sites of crosslinks were varied to examine their effects on resin thermo-oxidative stability and glass transition temperature (Tg) of the cured/postcured resins. A linear correlation of decreasing 316 C resin weight loss/surface area versus (1) decreasing aliphatic content, or (2) increasing benzylic/aliphatic content stoichiometry ratio over a wide range of resin compositions was observed. An almost linear correlation of Tg versus molecular distance between the crosslinks was also observed. An attempt was made to correlate Tg with initial composite mechanical properties (flexural strength and interlaminar shear strength). However, the scatter in mechanical strength data prevented obtaining a clear correlation. Instead, only a range of composite mechanical properties was obtained at 25, 288, and 316 C. Perhaps more importantly, what did become apparent during the correlation study was (1) the PMR methodology could be used to prepare composites from resins containing a wide variety of monomer modifications, (2) that these composites almost invariably provided satisfactory initial mechanical properties as long as the resins formulated exhibited satisfactory processing flow, and (3) that PMR resins exhibited predictable rates of 316 C weight loss/surface area based on their benzylic/aliphatic stoichiometery ratio.

  19. Post-irradiation hardness of resin-modified glass ionomer cements and a polyacid-modified composite resin

    International Nuclear Information System (INIS)

    Yap, A.U.J.

    1997-01-01

    This study examined the post-irradiation hardness of resin-modified glass ionomer cements and a polyacid-modified composite resin using a digital microhardness tester. Change in hardness of these materials over a period of 6 months was compared to that of conventional glass ionomer cements and a composite resin. With the exception of the composite resin, all materials showed a significant increase in hardness over 24 h after their initial set. Dual-cure resin-modified glass ionomer cements showed decreased hardness with increased storage time in saline at 37 o C. Results suggest that the addition of resins to glass ionomer cements does not improve initial hardness and does not negate the acid-base reaction of conventional cements. Resin addition may, however, lead to increased water sorption and decreased hardness. (author)

  20. Effect of various teas on color stability of resin composites.

    Science.gov (United States)

    Dinç Ata, Gül; Gokay, Osman; Müjdeci, Arzu; Kivrak, Tugba Congara; Mokhtari Tavana, Armin

    2017-12-01

    To investigate the effect of various teas on color stability of resin composites. Two methacrylate-based (Arabesk Top, Grandio) and a silorane-based (Filtek Silorane) resin composites were used. 110 cylindrical samples of each resin composite were prepared (2 mm thickness and 8 mm diameter), polished and stored in distilled water (37°C for 24 hours). They were randomly divided into 11 groups (n= 10) and color measurements were taken. Then the samples were immersed in tap water (control), a black tea, a green tea or one of the eight herbal-fruit teas (37°C for 1 week) and subsequently subjected to the final color measurements. The color change of samples (ΔE*) was calculated, data were subjected to two-way ANOVA and Tukey's HSD tests. Teas, resin composites and their interactions were significant (P= 0.000). All the teas and control caused color changes in all three resin composites. Rosehip tea caused the most color changes, while tap water showed the least in all resin composites. Arabesk Top had the most staining potential in all the teas and control, whereas Filtek Silorane was the most stain resistant except Grandio immersed in sage tea. Color stability of all resin composites used were affected from both structure of resin materials and constituents of teas used. All resin composites were susceptible to staining by all teas especially rosehip tea. Arabesk Top composite showed the greatest color susceptibility in all teas and Filtek Silorane the least with one exception. Color of resin composites can be negatively affected from teas consumed. Clinicians should advise patients that drinking different kind of teas could intensify surface staining of resin based restorations.

  1. Fracture frequency and longevity of fractured resin composite, polyacid-modified resin composite, and resin-modified glass ionomer cement class IV restorations: an up to 14 years of follow-up

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2010-01-01

    The aim of this study was to evaluate the fracture frequency and longevity of fractured class IV resin composite (RC), polyacid-modified resin composite (compomer; PMRC), and resin-modified glass ionomer cement (RMGIC) restorations in a longitudinal long-term follow-up. Eighty-five class IV RC (43...

  2. Microshear bond strength of composite resins to enamel and porcelain substrates utilizing unfilled versus filled resins.

    Science.gov (United States)

    Najafi-Abrandabadi, Ahmad; Najafi-Abrandabadi, Siamak; Ghasemi, Amir; Kotick, Philip G

    2014-11-01

    Failures such as marginal discoloration and composite chipping are still the problems of tooth-colored restorations on the substrate of enamel and porcelain, which some of these problems are consequently as a result of failures in the bonding layer. Using filled resin has been recently introduced to increase the bond strength of this layer. The aim of this study was to compare the microshear bond strength (μ-SBS) of composite resins to enamel incubated in periods of 24 h and 9 months and porcelain with unfilled resin and flowable composites (filled resin). In this in vitro study, two groups of 75 enamel samples with different storage times (24 h and 9 months) and a group of 75 porcelain samples were used. They were divided into 5 experimental groups of 15 samples in each. Composite cylinders in tygon tubes were bonded on the surface of acid-etched enamel and pretreated porcelain. Wave, Wave MV, Wave HV, Grandioflow and Margin Bond were used as bonding agents. The μ-SBS was measured at the speed of 1.0 mm/min. The bond strengths were analyzed with one-way analysis of variance (ANOVA) test followed by Tukey test. P composites (filled resins) can be used instead of unfilled resins in bonding composite resins to enamel and porcelain substrates.

  3. Clinical performance of a hybrid resin composite with and without an intermediate layer of flowable resin composite: a 7-year evaluation

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2011-01-01

    The objective of this prospective clinical follow up was to evaluate the long term clinical performance of a hybrid resin composite in Class II restorations with and without intermediate layer of flowable resin composite....

  4. Color change of composite resins subjected to accelerated artificial aging.

    Science.gov (United States)

    Tornavoi, Denise Cremonezzi; Agnelli, José Augusto Marcondes; Panzeri, Heitor; Dos Reis, Andréa Cândido

    2013-01-01

    The aim of this study was to evaluate the influence of accelerated artificial aging (AAA) on the color change of composite resins used in dentistry. Three composite resins were evaluated: Two microhybrids and one hybrid of higher viscosity, with different amounts and sizes of filler particles, shades C2 and B2. A total of 54 specimens were obtained (18 for each composite resin), made of a Teflon matrix (15 mm in diameter and 2 mm in height). The color measurements were obtained with a Spectrophotometer, (PCB 6807 BYK Gardner) before and after AAA. Data were submitted to the Kolmogorov-Smirnov test (α >0.05), ANOVA and Tukey test (α 3). Considering the variable ∆E, it was observed that the color tone C2 was already statistically different for the microhybrid composite resin prior to AAA (P aging the composite resin hybrid of higher viscosity B2 showed the highest color variation rate and microhybrid with zirconium/silica C2 showed the lowest. All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2) and after (B2). It was also observed color difference within a group of the same composite resin and same hue.

  5. Effect of photoactivation on the reduction of composite resin contamination.

    Science.gov (United States)

    Pauletti, Natalia A; Girotto, Luiza P S; Leite, Françoise H S; Mario, Débora N

    2017-06-01

    Composite resins are predominantly marketed in developing countries in tube form, and the contents of the tube may be used in numerous procedures for different patients. This represents a problem because of the risk of cross-contamination. This study aimed to evaluate contamination in vitro of the internal contents of composite resin tubes in the dental clinics of a higher-education institution, as well as the effect of photoactivation on the level of contamination. Twenty-five tubes containing composite resin were randomly chosen (by lottery). From each tube, two samples of approximately 2 mm of composite resin were removed, and then one sample, but not the other, was photoactivated. These samples were plated on Brain-Heart Infusion (BHI), Sabouraud and MacConkey agars, and the plates were incubated at 37°C for 24-48 h. Colony counting and Gram staining were performed for subsequent microscopic identification of fungi and bacteria. The non-photoactivated composite resin group presented significantly higher microbial contamination in relation to the photoactivated composite resin group. The photoactivation of camphorquinone present in composite resin produces reactive oxygen species, which might promote cell death of contaminant microorganisms. Thus, although the same tube of composite resin may be used for a number of different patients in the dental clinics of developing countries, the photoactivation process potentially reduces the risk of cross-contamination. © 2017 Eur J Oral Sci.

  6. Composite resin fillings and inlays: An 11-year evaluation

    DEFF Research Database (Denmark)

    Pallesen, U.; Qvist, V.

    2003-01-01

    Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth......Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth...

  7. Compatibility between dental adhesive systems and dual-polymerizing composite resins.

    Science.gov (United States)

    Michaud, Pierre-Luc; MacKenzie, Alexandra

    2016-10-01

    Information is lacking about incompatibilities between certain types of adhesive systems and dual-polymerizing composite resins, and universal adhesives have yet to be tested with these resins. The purpose of this in vitro study was to investigate the bonding outcome of dual-polymerizing foundation composite resins by using different categories of adhesive solutions and to determine whether incompatibilities were present. One hundred and eighty caries-free, extracted third molar teeth were allocated to 9 groups (n=20), in which 3 different bonding agents (Single Bond Plus [SB]), Scotchbond Multi-purpose [MP], and Scotchbond Universal [SU]) were used to bond 3 different composite resins (CompCore AF [CC], Core Paste XP [CP], and Filtek Supreme Ultra [FS]). After restorations had been fabricated using an Ultradent device, the specimens were stored in water at 37°C for 24 hours. The specimens were tested under shear force at a rate of 0.5 mm/min. The data were analyzed with Kruskal-Wallis tests and post hoc pairwise comparisons (α=.05). All 3 composite resins produced comparable shear bond strengths when used with MP (P=.076). However, when either SB or SU was used, the light-polymerized composite resin (FS) and 1 dual-polymerized foundation composite resin (CC) bonded significantly better than the other dual-polymerized foundation composite resin (CP) (Pincompatibilities exist between different products. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  8. Color change of composite resins subjected to accelerated artificial aging

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2013-01-01

    Conclusions: All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2 and after (B2. It was also observed color difference within a group of the same composite resin and same hue.

  9. Surface discoloration of composite resins: Effects of staining and bleaching.

    Science.gov (United States)

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2012-09-01

    The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet•X HD, Clearfil AP-X, Gradia Direct) and five nanohybrid composite resins (Ceram•X, GC Kalore, G-aenial, Grandio, GrandioSO), after staining and bleaching procedures. The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany) into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness) to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h), for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco). The color of specimens was measured with a spectrophotometer according to the CIE L(*)a(*)b(*) system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DEab(*)) between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA). All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested.

  10. Versatile composite resins simplifying the practice of restorative dentistry.

    Science.gov (United States)

    Margeas, Robert

    2014-01-01

    After decades of technical development and refinement, composite resins continue to simplify the practice of restorative dentistry, offering clinicians versatility, predictability, and enhanced physical properties. With a wide range of products available today, composite resins are a reliable, conservative, multi-functional restorative material option. As manufacturers strive to improve such properties as compression strength, flexural strength, elastic modulus, coefficient of thermal expansion, water sorption, and wear resistance, several classification systems of composite resins have been developed.

  11. Nanomechanical properties of dental resin-composites.

    Science.gov (United States)

    El-Safty, S; Akhtar, R; Silikas, N; Watts, D C

    2012-12-01

    To determine by nanoindentation the hardness and elastic modulus of resin-composites, including a series with systematically varied filler loading, plus other representative materials that fall into the categories of flowable, bulk-fill and conventional nano-hybrid types. Ten dental resin-composites: three flowable, three bulk-fill and four conventional were investigated using nanoindentation. Disc specimens (15mm×2mm) were prepared from each material using a metallic mold. Specimens were irradiated in the mold at top and bottom surfaces in multiple overlapping points (40s each) with light curing unit at 650mW/cm(2). Specimens were then mounted in 3cm diameter phenolic ring forms and embedded in a self-curing polystyrene resin. After grinding and polishing, specimens were stored in distilled water at 37°C for 7 days. Specimens were investigated using an Agilent Technologies XP nanoindenter equipped with a Berkovich diamond tip (100nm radius). Each specimen was loaded at one loading rate and three different unloading rates (at room temperature) with thirty indentations, per unloading rate. The maximum load applied by the nanoindenter to examine the specimens was 10mN. Dependent on the type of the resin-composite material, the mean values ranged from 0.73GPa to 1.60GPa for nanohardness and from 14.44GPa to 24.07GPa for elastic modulus. There was a significant positive non-linear correlation between elastic modulus and nanohardness (r(2)=0.88). Nonlinear regression revealed a significant positive correlation (r(2)=0.62) between elastic moduli and filler loading and a non-significant correlation (r(2)=0.50) between nanohardness and filler loading of the studied materials. Varying the unloading rates showed no consistent effect on the elastic modulus and nanohardness of the studied materials. For a specific resin matrix, both elastic moduli and nanohardness correlated positively with filler loading. For the resin-composites investigated, the group-average elastic

  12. Understanding of the color in composite resin

    Directory of Open Access Journals (Sweden)

    Jeong-Won Park

    2011-07-01

    Full Text Available In clinic, esthetic restoration of a defective natural tooth with composite resin is challenging procedure and needs complete understanding of the color of tooth itself and materials used. The optical characteristics of the composites are different because the chemical compositions and microstructures are not same. This review provided basic knowledge of the color and the color measurement devices, and analyze the color of the natural tooth. Further, the accuracy of the shade tab, color of the composite resins before and after curing, effect of the water, food and bleaching agent, and translucency, opalescence, and fluorescence effects were evaluated.

  13. Composite fabrication via resin transfer molding technology

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, G.M.; Domeier, L.A.

    1996-04-01

    The IMPReS (Integrated Modeling and Processing of Resin-based Structures) Program was funded in FY95 to consolidate, evaluate and enhance Sandia`s capabilities in the design and fabrication of composite structures. A key driver of this and related programs was the need for more agile product development processes and for model based design and fabrication tools across all of Sandia`s material technologies. A team of polymer, composite and modeling personnel was assembled to benchmark Sandia`s existing expertise in this area relative to industrial and academic programs and to initiate the tasks required to meet Sandia`s future needs. RTM (Resin Transfer Molding) was selected as the focus composite fabrication technology due to its versatility and growing use in industry. Modeling efforts focused on the prediction of composite mechanical properties and failure/damage mechanisms and also on the uncured resin flow processes typical of RTM. Appropriate molds and test composites were fabricated and model validation studies begun. This report summarizes and archives the modeling and fabrication studies carried out under IMPReS and evaluates the status of composite technology within Sandia. It should provide a complete and convenient baseline for future composite technology efforts within Sandia.

  14. Relationship between Color and Translucency of Multishaded Dental Composite Resins

    Directory of Open Access Journals (Sweden)

    Homan Naeimi Akbar

    2012-01-01

    Full Text Available The aim of the present study was to compare the translucency of different shades of two highly aesthetic multilayered restorative composite resins. In total nine shades from Esthet.X and ten shades from Filtek Supreme composite resins were chosen. Discs of each shade were prepared (N=3 and light-cured. Total and diffuse transmittance values for each sample were measured. Statistical analysis showed that the opaque dentine shades of both composites were the least translucent and the enamel shades had the highest translucency. There was a significant decrease in translucency from A2 to C2 of regular body shades and also from A4 to C4 of opaque dentine shades of Esthet.X composite resin. Grey enamel shade had a significantly higher diffuse translucency compared to clear and yellow enamel shades. There was a significant decrease in translucency from A2B to D2B and also in diffuse translucency from A4D to C6D shades of Filtek Supreme composite resin. It can be concluded that the color of the composite resins tested in this study had a significant effect on their translucency. Information on the translucency of different shades of composite resins can be very useful for the clinicians in achieving optimal esthetic restorative outcome.

  15. Marginal adaptation of composite resins under two adhesive techniques.

    Science.gov (United States)

    Dačić, Stefan; Veselinović, Aleksandar M; Mitić, Aleksandar; Nikolić, Marija; Cenić, Milica; Dačić-Simonović, Dragica

    2016-11-01

    In the present research, different adhesive techniques were used to set up fillings with composite resins. After the application of etch and rinse or self etch adhesive technique, marginal adaptation of composite fillings was estimated by the length of margins without gaps, and by the microretention of resin in enamel and dentin. The study material consisted of 40 extracted teeth. Twenty Class V cavities were treated with 35% phosphorous acid and restored after rinsing by Adper Single Bond 2 and Filtek Ultimate-ASB/FU 3M ESPE composite system. The remaining 20 cavities were restored by Adper Easy One-AEO/FU 3M ESPE composite system. Marginal adaptation of composite fillings was examined using a scanning electron microscope (SEM). The etch and rinse adhesive technique showed a significantly higher percentage of margin length without gaps (in enamel: 92.5%, in dentin: 57.3%), compared with the self-etch technique with lower percentage of margin length without gaps, in enamel 70.4% (p resin tugs in interprismatic spaces of enamel, while the dentin microretention was composed of adhesive and hybrid layers with resin tugs in dentin canals. In the second technique, resin tugs were rarely seen and a microgap was dominant along the border of restoration margins. The SEM analysis showed a better marginal adaptation of composite resin to enamel and dentin with better microretention when the etch and rinse adhesive procedure was applied. © 2016 Wiley Periodicals, Inc.

  16. Salivary bisphenol A levels and their association with composite resin restoration.

    Science.gov (United States)

    Lee, Jung-Ha; Yi, Seung-Kyoo; Kim, Se-Yeon; Kim, Ji-Soo; Son, Sung-Ae; Jeong, Seung-Hwa; Kim, Jin-Bom

    2017-04-01

    Composite resin has been increasingly used in an effort to remove minimal amount of tooth structure and are used for restoring not just carious cavities but also cervical abrasion. To synthesize composite resin, bisphenol A (BPA) is used. The aim of the study was to measure the changes in salivary BPA level related with composite resin restoration. ELISA was used to examine the BPA levels in the saliva collected from 30 volunteers whose teeth were filled with composite resin. Salivary samples were collected immediately before filling and 5 min and 7 d after filling. Wilcoxon signed-ranks test and linear regression were performed to test the significant differences of the changes in BPA levels in saliva. Before a new composite resin filling, there was no significant difference between with and without existing filling of composite resin and BPA level in the saliva was not correlated to the number of filled surfaces with composite resin. However, BPA level in the saliva increased to average 3.64 μg/L from average 0.15 μg/L after filling 5 min. BPA level increased in proportion with the number of filled surfaces. BPA level decreased to average 0.59 after filling 7 d. However it was higher than the BPA level before a new composite resin filling. Considering 50 μg/kg/day as the Tolerable Daily Intake of BPA suggested by European Food Safety Authority, the amount of BPA eluted in saliva after the composite resin filling is considered a safe level that is not a hazard to health at all. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Method for curing alkyd resin compositions by applying ionizing radiation

    International Nuclear Information System (INIS)

    Watanabe, T.; Murata, K.; Maruyama, T.

    1975-01-01

    An alkyd resin composition is prepared by dissolving a polymerizable alkyd resin having from 10 to 50 percent of oil length into a vinyl monomer. The polymerizable alkyd resin is obtained by a half-esterification reaction of an acid anhydride having a polymerizable unsaturated group and an alkyd resin modified with conjugated unsaturated oil having at least one reactive hydroxyl group per one molecule. The alkyd resin composition thus obtained is coated on an article, and ionizing radiation is applied on the article to cure the coated film thereon. (U.S.)

  18. Fatigue resistance of CAD/CAM resin composite molar crowns.

    NARCIS (Netherlands)

    Shembish, F.A.; Tong, H.; Kaizer, M.; Janal, M.N.; Thompson, V.P.; Opdam, N.J.M.; Zhang, Y.

    2016-01-01

    OBJECTIVE: To demonstrate the fatigue behavior of CAD/CAM resin composite molar crowns using a mouth-motion step-stress fatigue test. Monolithic leucite-reinforced glass-ceramic crowns were used as a reference. METHODS: Fully anatomically shaped monolithic resin composite molar crowns (Lava

  19. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    DEFF Research Database (Denmark)

    Franco, Eduardo Batista; Benetti, Ana Raquel; Ishikiriama, Sérgio Kiyoshi

    2006-01-01

    To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions.......To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions....

  20. Restoration of traumatized teeth with resin composites

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2018-01-01

    For a long time, the primary choice for initial restoration of a crown-fractured front tooth has been resin composite material. The restoration can in most cases be performed immediately after injury if there is no sign of periodontal injury. The method’s adhesive character is conservative to tooth...... present an aesthetic problem due to exposure of un-aesthetic crown-margins. The invasive permanent crown restorations are therefore often not suc-cessful on a long-term scale. On the other hand, a conservative direct restoration of an extensively fractured incisor crown with resin composite may......-structure and with minimal risk of pulpal complication. In addition, it offers an aesthetic solution to the patient immediately after an injury, which may bring a little comfort in a sad situation. The resin composite build-up is often changed or repaired a couple of times, before the tooth is restored with a porcelain...

  1. A qualitative chemometric study of resin composite polymerization

    Directory of Open Access Journals (Sweden)

    Regina Ferraz Mendes

    2008-01-01

    Full Text Available Objective: An experiment was carried out to assess the effect produced by different polymerization techniques on resin composite color after it has been immersed in coffee. Methods: Samples were manufactured using TPH Spectrum composite. It was polymerized for 10 or 40 seconds, with the light tip at one or zero millimeters from the resin surface, and afterwards the samples were immersed in coffee for 24 hours or 7 days. Ten different evaluators classified the samples according to their degree of staining. Results: The samples that were polymerized for 10 seconds were more susceptible to staining than the ones polymerized by 40 seconds. Samples immersed in coffee for 7 days were more susceptible to staining than the ones immersed for 24 hours. Conclusion: The variables polymerization time and immersion time were determinant in the staining susceptibility of the studied composite by coffee. However, there was no significant difference, irrespective of whether the resin was polymerized 10 or zero millimeters away from the resin surface.

  2. Temperature-dependence of creep behaviour of dental resin-composites.

    Science.gov (United States)

    El-Safty, S; Silikas, N; Watts, D C

    2013-04-01

    To determine the effect of temperature, over a clinically relevant range, on the creep behaviour of a set of conventional and flowable resin-composites including two subgroups having the same resin matrix and varied filler loading. Eight dental resin-composites: four flowable and four conventional were investigated. Stainless steel split moulds (4 mm × 6 mm) were used to prepare cylindrical specimens for creep examination. Specimens were irradiated in the moulds in layers of 2mm thickness (40s each), as well as from the radial direction after removal from the moulds, using a light-curing unit with irradiance of 650 mW/cm(2). A total of 15 specimens from each material were prepared and divided into three groups (n=5) according to the temperature; Group I: (23°C), Group II: (37°C) and Group III: (45°C). Each specimen was loaded (20 MPa) for 2h and unloaded for 2h. Creep was measured continuously over the loading and unloading periods. At higher temperatures greater creep and permanent set were recorded. The lowest mean creep occurred with GS and GH resin-composites. Percentage of creep recovery decreased at higher temperatures. At 23°C, the materials exhibited comparable creep. At 37°C and 45°C, however, there was a greater variation between materials. For all resin-composites, there was a strong linear correlation with temperature for both creep and permanent set. Creep parameters of resin-composites are sensitive to temperature increase from 23 to 45°C, as can occur intra-orally. For a given resin matrix, creep decreased with higher filler loading. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Resin flow/fiber deformation model for composites

    International Nuclear Information System (INIS)

    Gutowski, T.G.

    1985-01-01

    This paper presents a resin flow/fiber deformation model that can be used to predict the behavior of composites during the molding cycle. The model can take into account time varying pressure and viscosity and output the time history of the fiber volume fraction. With this known, the composite thickness, resin pressure, and fiber pressure can all be determined as a function of time. The results of this model are in good agreement with experimentally measured values. 10 references, 9 figures

  4. Analysis of surface hardness of artificially aged resin composites

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2012-02-01

    Full Text Available This study evaluated the effect of artificially accelerated aging (AAA on the surface hardness of eight composite resins: Filtek Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma, and Filtek Z100. Sixteen specimens were made from the test piece of each material, using an 8.0 × 2.0 mm teflon matrix. After 24 hours, eight specimens from each material were submitted to three surface hardness readings using a Shimadzu Microhardness Tester for 5 seconds at a load of 50 gf. The other eight specimens remained in the artificially accelerated aging machine for 382 hours and were submitted to the same surface hardness analysis. The means of each test specimen were submitted to the Kolmogorov-Smirnov test (p > 0.05, ANOVA and Tukey test (p < 0.05. With regard to hardness (F = 86.74, p < 0.0001 the analysis showed significant differences among the resin composite brands. But aging did not influence the hardness of any of the resin composites (F = 0.39, p = 0.53. In this study, there was interaction between the resin composite brand and the aging factors (F = 4.51, p < 0.0002. It was concluded that notwithstanding the type of resin, AAA did not influence surface hardness. However, with regard to hardness there was a significant difference among the resin brands.

  5. Polishing and toothbrushing alters the surface roughness and gloss of composite resins.

    Science.gov (United States)

    Kamonkhantikul, Krid; Arksornnukit, Mansuang; Takahashi, Hidekazu; Kanehira, Masafumi; Finger, Werner J

    2014-01-01

    This study aimed to investigate the surface roughness and gloss of composite resins after using two polishing systems and toothbrushing. Six composite resins (Durafill VS, Filtek Z250, Filtek Z350 XT, Kalore, Venus Diamond, and Venus Pearl) were evaluated after polishing with two polishing systems (Sof-Lex, Venus Supra) and after toothbrushing up to 40,000 cycles. Surface roughness (Ra) and gloss were determined for each composite resin group (n=6) after silicon carbide paper grinding, polishing, and toothbrushing. Two-way ANOVA indicated significant differences in both Ra and gloss between measuring stages for the composite resins tested, except Venus Pearl, which showed significant differences only in gloss. After polishing, the Filtek Z350 XT, Kalore, and Venus Diamond showed significant increases in Ra, while all composite resin groups except the Filtek Z350 XT and Durafill VS with Sof-Lex showed increases in gloss. After toothbrushing, all composite resin demonstrated increases in Ra and decreases in gloss.

  6. Resin-composite blocks for dental CAD/CAM applications.

    Science.gov (United States)

    Ruse, N D; Sadoun, M J

    2014-12-01

    Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials. © International & American Associations for Dental Research.

  7. Matrix resin effects in composite delamination - Mode I fracture aspects

    Science.gov (United States)

    Hunston, Donald L.; Moulton, Richard J.; Johnston, Norman J.; Bascom, Willard D.

    1987-01-01

    A number of thermoset, toughened thermoset, and thermoplastic resin matrix systems were characterized for Mode I critical strain energy release rates, and their composites were tested for interlaminar critical strain energy release rates using the double cantilever beam method. A clear correlation is found between the two sets of data. With brittle resins, the interlaminar critical strain energy release rates are somewhat larger than the neat resin values due to a full transfer of the neat resin toughness to the composite and toughening mechanisms associated with crack growth. With tougher matrices, the higher critical strain energy release rates are only partially transferred to the composites, presumably because the fibers restrict the crack-tip deformation zones.

  8. Differences in interfacial bond strengths of graphite fiber-epoxy resin composites

    Science.gov (United States)

    Needles, H. L.

    1985-01-01

    The effect of epoxy-size and degree of cure on the interfacial bonding of an epoxy-amine-graphite fiber composite system is examined. The role of the fiber-resin interface in determining the overall mechanical properties of composites is poorly understood. A good interfacial adhesive bond is required to achieve maximum stress transfer to the fibers in composites, but at the same time some form of energy absorbing interfacial interaction is needed to achieve high fracture toughening. The incompatibility of these two processes makes it important to understand the nature and basic factors involved at the fiber-resin interface as stress is applied. The mechanical properties including interlaminar shear values for graphite fiber-resin composites are low compared to glass and boron-resin composites. These differences have been attributed to poor fiber-matrix adhesion. Graphite fibers are commonly subjected to post-treatments including application of organic sizing in order to improve their compatibility with the resin matrix and to protect the fiber tow from damage during processing and lay-up. In such processes, sized graphite fiber tow is impregnated with epoxy resin and then layed-up i nto the appropriate configuration. Following an extended ambient temperature cure, the graphite-resin composite structure is cured at elevated temperature using a programmed temperature sequence to cure and then cool the product.

  9. Effect of preheat repetition on color stability of methacrylate- and silorane-based composite resins.

    Science.gov (United States)

    Abed Kahnamouei, Mehdi; Gholizadeh, Sarah; Rikhtegaran, Sahand; Daneshpooy, Mehdi; Kimyai, Soodabeh; Alizadeh Oskoee, Parnian; Rezaei, Yashar

    2017-01-01

    Background. The aim of this study was to investigate the effect of preheating methacrylate- and silorane-based composite resins on their color stability up to 40 times at 55‒60°C. Methods. Seventy-six methacrylate and silorane-based composite resin samples, with a diameter of 10 mm and a height of 2 mm, were divided into 4 groups (n=19). After the samples were prepared, their color parameters were determined using a reflective spectrophotometer. The composite resin samples were separately stored in a solution of tea for 40 consecutive days. Then the samples underwent a color determination procedure again using a spectrophotometer and color changes were recorded. Finally two-way ANOVA was used to study the effect of composite temperature on its staining (Pcomposite resin samples compared to non-heated samples at P=0.005 and P=0.029 for silorane-based and Z250 composite resin samples, respectively. Results. Both composite resin type (P=0.014) and preheating (Pcomposite resin samples, up to 55‒60°C for 40 rounds, resulted in more color changes compared with unheated composite resin samples. After storage in a solution of tea the color change rate in the composite resin samples of silorane-based was higher than the Z250 composite resin samples.

  10. ADHESIVE SYSTEM AFFECTS REPAIR BOND STRENGTH OF RESIN COMPOSITE

    Directory of Open Access Journals (Sweden)

    Özgür IRMAK

    2017-10-01

    Full Text Available Purpose: This study evaluated the effects of different adhesive systems on repair bond strength of aged resin composites. Materials and Methods: Ninety composite discs were built and half of them were subjected to thermal aging. Aged and non-aged specimens were repaired with resin composite using three different adhesive systems; a two-step self-etch adhesive, a two-step total-etch adhesive and a one-step self-etch adhesive; then they were subjected to shear forces. Data were analyzed statistically. Results: Adhesive type and aging significantly affected the repair bond strengths (p<0.0001. No statistical difference was found in aged composite groups repaired with two-step self- etch or two-step total-etch adhesive. One-step self-etch adhesive showed lower bond strength values in aged composite repair (p<0.0001. Conclusion: In the repair of aged resin composite, two-step self-etch and two-step total-etch adhesives exhibited higher shear bond strength values than that of one-step self-etch adhesive.

  11. High performance dental resin composites with hydrolytically stable monomers.

    Science.gov (United States)

    Wang, Xiaohong; Huyang, George; Palagummi, Sri Vikram; Liu, Xiaohui; Skrtic, Drago; Beauchamp, Carlos; Bowen, Rafael; Sun, Jirun

    2018-02-01

    The objectives of this project were to: 1) develop strong and durable dental resin composites by employing new monomers that are hydrolytically stable, and 2) demonstrate that resin composites based on these monomers perform superiorly to the traditional bisphenol A glycidyl dimethacrylate/triethylene glycol dimethacrylate (Bis-GMA/TEGDMA) composites under testing conditions relevant to clinical applications. New resins comprising hydrolytically stable, ether-based monomer, i.e., triethylene glycol divinylbenzyl ether (TEG-DVBE), and urethane dimethacrylate (UDMA) were produced via composition-controlled photo-polymerization. Their composites contained 67.5wt% of micro and 7.5wt% of nano-sized filler. The performances of both copolymers and composites were evaluated by a battery of clinically-relevant assessments: degree of vinyl conversion (DC: FTIR and NIR spectroscopy); refractive index (n: optical microscopy); elastic modulus (E), flexural strength (F) and fracture toughness (K IC ) (universal mechanical testing); Knoop hardness (HK; indentation); water sorption (W sp ) and solubility (W su ) (gravimetry); polymerization shrinkage (S v ; mercury dilatometry) and polymerization stress (tensometer). The experimental UDMA/TEG-DVBE composites were compared with the Bis-GMA/TEGDMA composites containing the identical filler contents, and with the commercial micro hybrid flowable composite. UDMA/TEG-DBVE composites exhibited n, E, W sp , W su and S v equivalent to the controls. They outperformed the controls with respect to F (up to 26.8% increase), K IC (up to 27.7% increase), modulus recovery upon water sorption (full recovery vs. 91.9% recovery), and stress formation (up to 52.7% reduction). In addition, new composites showed up to 27.7% increase in attainable DC compared to the traditional composites. Bis-GMA/TEGDMA controls exceeded the experimental composites with respect to only one property, the composite hardness. Significantly, up to 18.1% lower HK values in

  12. Polymerization shrinkage stress of composite resins and resin cements - What do we need to know?

    Science.gov (United States)

    Soares, Carlos José; Faria-E-Silva, André Luis; Rodrigues, Monise de Paula; Vilela, Andomar Bruno Fernandes; Pfeifer, Carmem Silvia; Tantbirojn, Daranee; Versluis, Antheunis

    2017-08-28

    Polymerization shrinkage stress of resin-based materials have been related to several unwanted clinical consequences, such as enamel crack propagation, cusp deflection, marginal and internal gaps, and decreased bond strength. Despite the absence of strong evidence relating polymerization shrinkage to secondary caries or fracture of posterior teeth, shrinkage stress has been associated with post-operative sensitivity and marginal stain. The latter is often erroneously used as a criterion for replacement of composite restorations. Therefore, an indirect correlation can emerge between shrinkage stress and the longevity of composite restorations or resin-bonded ceramic restorations. The relationship between shrinkage and stress can be best studied in laboratory experiments and a combination of various methodologies. The objective of this review article is to discuss the concept and consequences of polymerization shrinkage and shrinkage stress of composite resins and resin cements. Literature relating to polymerization shrinkage and shrinkage stress generation, research methodologies, and contributing factors are selected and reviewed. Clinical techniques that could reduce shrinkage stress and new developments on low-shrink dental materials are also discussed.

  13. The effect of soda immersion on nano hybrid composite resin discoloration

    Directory of Open Access Journals (Sweden)

    M. Chair Effendi

    2014-03-01

    Full Text Available Background: Composite resin is the tooth-colored restorative material which most of the people are fond of due to their aesthetic value. The composite resin discoloration may happen because of the intrinsic and extrinsic factors. Soda water is one of the beverages which can cause the composite resin discoloration. Purpose: The study was aimed to determine the effect of soda immersion on nano hybrid composite resin discoloration. Methods: The study was an experimental laboratory study using 100 shade A3 nano hybrid composite resin specimens with the diameter of 5 mm and density of 2mm. The samples were divided into 5 groups, each group was immersed in different beverages. The beverages were mineral water; lemon-flavored soda; strawberry-flavored soda; fruit punch-flavored soda; and orange-flavored soda for 3, 7, 14 and 21 days respectively, in the temperature of 37o C. The discoloration measurement utilizes Spectrophotometer, Vita Easy Shade, and uses CIEL*a*b* method. Results: The result showed that the duration of immersion in soda had an effect on the Nano hybrid composite resin discoloration. Strawberry and fruit punch- flavored soda were the most influential components toward the discoloration. Nevertheless, the generally-occurred discoloration was clinically acceptable (∆E ≤ 3,3. Conclusion: The study suggested that the soda immersion duration has effect on Nano hybrid composite resin discoloration.Latar belakang: Resin komposit adalah material sewarna gigi yang diminati masyarakat karena memiliki nilai estetik yang baik. Perubahan warna resin komposit dapat terjadi karena faktor intrinsik dan ekstrinsik. Minuman soda merupakan salah satu minuman yang dapat menyebabkan perubahan warna pada resin komposit. Tujuan: Tujuan dari penelitian ini untuk meneliti perubahan warna resin komposit nanohibrida akibat perendaman dalam minuman soda. Metode: Metode yang digunakan pada penelitian ini adalah eksperimental laboratorik dengan menggunakan

  14. Effects of air-polishing powders on color stability of composite resins.

    Science.gov (United States)

    Güler, Ahmet Umut; Duran, Ibrahim; Yücel, Ali Çağin; Ozkan, Pelin

    2011-10-01

    The purpose of this study was to investigate the effect of different air-polishing powders on the color stability of different types of composite resin restorative materials. Thirty cylindrical specimens (15×2 mm) were prepared for each of 7 composite resin restorative materials. All specimens were polished with a series of aluminum oxide polishing discs (Sof-Lex). The prepared specimens of each composite resin were randomly divided into 3 groups of 10 specimens each, for control (Group-C) and two air-powder applications (Group-CP: Cavitron Prophy-Jet; Group-PS: Sirona ProSmile prophylaxis powder). A standard air-polishing unit (ProSmile Handly) was used. All specimens were air-powdered for 10 s at 4-bar pressure. The distance of the spray nosel from the specimens was approximately 10 mm and angulation of the nosel was 90°. Specimens were stored in 100 mL of coffee (Nescafe Classic) for 24 h at 37°C. Color measurement of all specimens was recorded before and after exposure to staining agent with a colorimeter (Minolta CR-300). Color differences (∆E*) between the 2 color measurements (baseline and after 24 h storage) were calculated. The data were analyzed with a 2-way ANOVA test, and mean values were compared by the Tukey HSD test (p.05) and these groups demonstrated the highest ∆E* values. For Filtek Silorane and IntenS, the highest ∆E* values were observed in Group-PS. The lowest ∆E* values for all composite resin groups were observed in Group-C. When comparing the 7 composite resin restorative materials, Aelite Aesthetic Enemal demonstrated significantly less ∆E* values than the other composite resins tested. The highest ∆E* values were observed in Quixfil. Except for Quixfil, all control groups of composite resins that were polished Sof-Lex exhibited clinically acceptable ∆E values (<3.7). Air-polishing applications increased the color change for all composite resin restorative materials tested. Composite restorations may require re

  15. Effects of air-polishing powders on color stability of composite resins

    Directory of Open Access Journals (Sweden)

    Ahmet Umut Güler

    2011-10-01

    Full Text Available OBJECTIVES: The purpose of this study was to investigate the effect of different air-polishing powders on the color stability of different types of composite resin restorative materials. MATERIAL AND METHODS: Thirty cylindrical specimens (15×2 mm were prepared for each of 7 composite resin restorative materials. All specimens were polished with a series of aluminum oxide polishing discs (Sof-Lex. The prepared specimens of each composite resin were randomly divided into 3 groups of 10 specimens each, for control (Group-C and two air-powder applications (Group-CP: Cavitron Prophy-Jet; Group-PS: Sirona ProSmile prophylaxis powder. A standard air-polishing unit (ProSmile Handly was used. All specimens were air-powdered for 10 s at 4-bar pressure. The distance of the spray nosel from the specimens was approximately 10 mm and angulation of the nosel was 90°. Specimens were stored in 100 mL of coffee (Nescafe Classic for 24 h at 37°C. Color measurement of all specimens was recorded before and after exposure to staining agent with a colorimeter (Minolta CR-300. Color differences (∆E* between the 2 color measurements (baseline and after 24 h storage were calculated. The data were analyzed with a 2-way ANOVA test, and mean values were compared by the Tukey HSD test (p.05 and these groups demonstrated the highest ∆E* values. For Filtek Silorane and IntenS, the highest ∆E* values were observed in Group-PS. The lowest ∆E* values for all composite resin groups were observed in Group-C. When comparing the 7 composite resin restorative materials, Aelite Aesthetic Enemal demonstrated significantly less ∆E* values than the other composite resins tested. The highest ∆E* values were observed in Quixfil. CONCLUSION: Except for Quixfil, all control groups of composite resins that were polished Sof-Lex exhibited clinically acceptable ∆E values (<3.7. Air-polishing applications increased the color change for all composite resin restorative materials

  16. Wear of resin composites: Current insights into underlying mechanisms, evaluation methods and influential factors

    Directory of Open Access Journals (Sweden)

    Akimasa Tsujimoto

    2018-05-01

    Full Text Available Summary: The application of resin composites in dentistry has become increasingly widespread due to the increased aesthetic demands of patients, improvements in the formulation of resin composites, and the ability of these materials to bond to tooth structures, together with concerns about dental amalgam fillings. As resistance to wear is an important factor in determining the clinical success of resin composite restoratives, this review article defines what constitutes wear and describes the major underlying phenomena involved in this process. Insights are further included on both in vivo and in vitro tests used to determine the wear resistance of resin composite and the relationships between these tests. The discussion focuses on factors that contribute to the wear of resin composite. Finally, future perspectives are included on both clinical and laboratory tests and on the development of resin composite restorations. Keywords: Resin composites, Wear resistance, Wear testing

  17. UV curing silicon-containing epoxy resin and its glass cloth reinforced composites

    International Nuclear Information System (INIS)

    Yang Guang; Tang Zhuo; Huang Pengcheng

    2007-01-01

    A UV-curable cationic silicon-containing epoxy resin formulation was developed. The gel conversion of the cured resin after 10-min UV irradiation reached 80% in the presence of 5% diaryliodonium salt photoinitiator and 5.5% polyol chain transfer agent by cationic ring-opening polymerization. The glass cloth-reinforced composites were fabricated with the silicon-containing epoxy resin using the wet lay-up technique and UV irradiation. The mechanical properties of the composites were evaluated. Compared with glass cloth reinforced bisphenol A epoxy resin matrix composites, the silicon-containing epoxy resin matrix composites possessed higher tensile strength and interlayer shear strength which was 158.5MPa and 9.9MPa respectively while other mechanical properties such as flexural property and tensile modulus were similar. (authors)

  18. Study on thermal conductive BN/novolac resin composites

    International Nuclear Information System (INIS)

    Li, Shasha; Qi, Shuhua; Liu, Nailiang; Cao, Peng

    2011-01-01

    Highlights: → Boron nitride (BN) particles were used to modify novolac resin. → BN particles were pretreated by γ-aminopropyltriethoxysilane. → The thermal conductivity trend of composite almost agrees with the predicted data from the Maxwell-Eucken model. → At BN concentration of 80 wt.%, thermal conductivity value of composite is 4.5 times that of pure novolac resin. → Combined use of the larger and smaller particles with a mass ratio of 1:2 provides the composites with the maximum thermal conductivity among the testing systems. → The composite thermal property also increases with an increase in the BN concentration. - Abstract: In this study, γ-aminopropyltriethoxysilane-treated boron nitride (BN) particles were used to modify novolac resin. The effect of varying the BN concentration, particle size, and hybrid BN fillers with the binary particle size distribution on the thermal conductivity of the composites was investigated. Scanning electron microscopy (SEM) imaging showed homogeneously dispersed treated BN particles in the matrix. Furthermore, the thermal conductivity increased as the BN concentration was increased. This behavior was also observed when the filler size was increased. Experimentally obtained thermal conductivity values agree with the predicted data from the Maxwell-Eucken model well at less than 70 wt.% BN loading. A larger particle size BN-filled novolac resin exhibits a higher thermal conductivity than a smaller particle size BN-filled one. The combined use of 0.5 and 15 μm particles with a mass ratio of 2:1 achieved the maximum thermal conductivity among the testing systems. The thermal resistance properties of the composites were also studied.

  19. Resin infusion of layered metal/composite hybrid and resulting metal/composite hybrid laminate

    Science.gov (United States)

    Cano, Roberto J. (Inventor); Grimsley, Brian W. (Inventor); Weiser, Erik S. (Inventor); Jensen, Brian J. (Inventor)

    2009-01-01

    A method of fabricating a metal/composite hybrid laminate is provided. One or more layered arrangements are stacked on a solid base to form a layered structure. Each layered arrangement is defined by a fibrous material and a perforated metal sheet. A resin in its liquid state is introduced along a portion of the layered structure while a differential pressure is applied across the laminate structure until the resin permeates the fibrous material of each layered arrangement and fills perforations in each perforated metal sheet. The resin is cured thereby yielding a metal/composite hybrid laminate.

  20. Radiation processed composite materials of wood and elastic polyester resins

    International Nuclear Information System (INIS)

    Tapolcai, I.; Czvikovszky, T.

    1983-01-01

    The radiation polymerization of multifunctional unsaturated polyester-monomer mixtures in wood forms interpenetrating network system. The mechanical resistance (compression, abrasion, hardness, etc.) of these composite materials are generally well over the original wood, however the impact strength is almost the same or even reduced, in comparison to the wood itself. An attempt is made using elastic polyester resins to produced wood-polyester composite materials with improved modulus of elasticity and impact properties. For the impregnation of European beech wood two types of elastic unsaturated polyester resins were used. The exothermic effect of radiation copolymerization of these resins in wood has been measured and the dose rate effects as well as hardening dose was determined. Felxural strength and impact properties were examined. Elastic unsaturated polyester resins improved the impact strength of wood composite materials. (author)

  1. Computerized mathematical model for prediction of resin/fiber composite properties

    International Nuclear Information System (INIS)

    Lowe, K.A.

    1985-01-01

    A mathematical model has been developed for the design and optimization of resin formulations. The behavior of a fiber-reinforced cured resin matrix can be predicted from constituent properties of the formulation and fiber when component interaction is taken into account. A computer implementation of the mathematical model has been coded to simulate resin/fiber response and generate expected values for any definable properties of the composite. The algorithm is based on multistage regression techniques and the manipulation of n-order matrices. Excellent correlation between actual test values and predicted values has been observed for physical, mechanical, and qualitative properties of resin/fiber composites. Both experimental and commercial resin systems with various fiber reinforcements have been successfully characterized by the model. 6 references, 3 figures, 2 tables

  2. Fracture strength testing of crowns made of CAD/CAM composite resins.

    Science.gov (United States)

    Okada, Ryota; Asakura, Masaki; Ando, Akihiro; Kumano, Hirokazu; Ban, Seiji; Kawai, Tatsushi; Takebe, Jun

    2018-03-28

    The purpose of this study was to ascertain whether computer aided design/computer aided manufacturing (CAD/CAM) composite resin crowns have sufficient strength to withstand the bite force of the molar teeth. The null hypothesis was that the fracture strength of CAD/CAM composite resin crowns is lower than the average maximum bite force of the molar tooth. The crowns, which shape is the right maxillary first molar, were fabricated using four CAD/CAM blanks made of composite resins (Block HC: HC, KZR-CAD HR: HR, KZR-CAD HR2: HR2, Avencia Block: AVE) and one CAD/CAM blank made of lithium disilicate glass-ceramic (IPS e.max CAD: IPS), which was used as a control. Fracture strength of fabricated crowns bonded to metal abutment and biaxial flexural strength of the materials were evaluated. The results of fracture strength test and biaxial flexural strength test showed different tendencies. The fracture strength of CAD/CAM composite resin crowns except HC ranged from 3.3kN to 3.9kN, and was similar to that of IPS (3.3kN). In contrast, biaxial flexural strength of CAD/CAM composite resins ranged from 175MPa to 247MPa, and was significantly lower than that of IPS (360MPa). All CAD/CAM composite resin crowns studied presented about 3-4 times higher fracture strength than the average maximum bite force of the molar tooth (700-900N), which result leads to the conclusion that CAD/CAM composite resin crowns would have sufficient strength to withstand the bite force of the molar teeth. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  3. Relative biocompatibility of micro-hybrid and nano-hybrid light-activated composite resins.

    Science.gov (United States)

    Olabisi Arigbede, Abiodun; Folasade Adeyemi, Bukola; Femi-Akinlosotu, Omowumi

    2017-01-01

    Background. In vitro studies have revealed a direct association between resin content and cytotoxicity of composite resins; however, implantation studies in this regard are sparse. This study investigates the relationship between filler content of composite resins and biocompatibility. Methods. This research employed twelve 180‒200-gr male Wistar rats, 1 nano-hybrid (Prime-Dent Inc.) and 1 micro-hybrid (Medental Inc.) composite resins containing 74% and 80‒90% filler content, respectively. The samples were assessed on the 2nd, 14th and 90th day of implantation. Four rats were allocated to each day in this experimental study. A section of 1.5mm long cured nano-hybrid and micro-hybrid materials were implanted into the right and left upper and lower limbs of the rats, respectively. Eight samples were generated on each day of observation. Inflammation was graded according to the criteria suggested by Orstavik and Major. Pearson's chi-squared test was employed to determine the relationship between the tissue responses of the two materials. Statistical significance was set at P resin had a score of 3.0 for cellular inflammation. On the 14th day, the micro-hybrid resin also exhibited a lower average grade for cellular inflammation. On the 90th day, the micro-hybrid resin had a higher grade of inflammation (0.9) compared to 0.3 recorded for nano-hybrid. The composite resins with higher filler content elicited a significantly lower grade of inflammation irrespective of the duration (χ=20.000, df=8, P=0.010) while the composite resins with lower filler content elicited a significantly lower inflammatory response on the 90th day (χ=4.000, df=1, P=0.046). Conclusion. The composite resins with higher filler content generally elicited significantly lower grades of inflammation, and the composite resins with lower filler content exhibited significantly lower inflammatory response on the 90th day of implantation.

  4. Influence of Bleaching Agents on Color and Translucency of Aged Resin Composites.

    Science.gov (United States)

    Lago, Maristela; Mozzaquatro, Lisandra R; Rodrigues, Camila; Kaizer, Marina R; Mallmann, André; Jacques, Letícia B

    2017-09-01

    Evaluate the influence of two bleaching agents (16% carbamide peroxide-CP and 35% hydrogen peroxide-HP) on color and translucency of one resin composite (Filtek Z350 XT) in two opacities (enamel and dentin) previously aged in deionized water or red wine. Sixty specimens of each material were divided in two groups (n = 30): aged in water or red wine for 14 days. Then the specimens were divided in three subgroups (n = 10): control/no treatment, treated with 16% carbamide peroxide (Mix Night), treated with 35% hydrogen peroxide (Mix One). Color readings were performed 24 hours after polishing (baseline); after the 14 days of aging; and after bleaching treatment. Color coordinates CIE L*a*b* were measured using a spectrophotometer (SP60 X-Rite). Color change (CIEDE2000) and translucency parameter were calculated. Data were analyzed with repeated measures two-way ANOVA, and Student-Newman-Keuls tests (5%). Bleaching decreased color change in stained resin composites (aged in red wine), whereas increased it in non-stained enamel resin composites (aged in water). CP had better bleaching results with stained resin composites than HP. Translucency of non-stained dentin resin composite decreased with aging, but did not change with bleaching. For stained resin composites, aging caused reduced translucency, whereas bleaching increased it. Effective bleaching of discolored resin composites aged in an acidic and alcoholic media rich in staining agents was achieved, improving color and translucency. Carbamide peroxide showed better performance than hydrogen peroxide for the bleaching of stained resin composites. (J Esthet Restor Dent 29:368-377, 2017). © 2016 Wiley Periodicals, Inc.

  5. Vickers microhardness comparison of 4 composite resins with different types of filler.

    Directory of Open Access Journals (Sweden)

    René García-Contreras

    2015-10-01

    Full Text Available Composite resins are the material of choice to restore minimal invasive cavities; conversely, it is important to explore the mechanical properties of commercially available dental materials. Objective: To compare the Vickers microhardness (VHN of four available commercial composite resins using standardized samples and methods. Methodology: Composite cylinders were manufactured in a Teflon mould. We used the follow composite resins (n=4/gp: Microhybrid resins [Feeling Lux (Viarden and Amelogen Plus (Ultradent], Hybrid resin [Te-Econom Plus (Ivoclar] and Nanohybrid resin [Filtek Z350 (3M ESPE]. All samples were incubated in distilled water at 37ºC for five days. The test was carried out with microhardness indenter at 10 N, and a dwelling time of 10 s for 9 indentations across the specimens resulting in a total of 36 indentations for each group. Data were subjected to Kolmogorov-Smirnov normality test and ANOVA (post-hoc Tukey test. Results: The VHN mean values ranged from harder to softer as follows: Filtek Z350 (71.96±6.44 (p Amelogen Plus (59.90±4.40 (p Feeling lux (53.52±5.72> Te-Econom Plus (53.26±5.19. Conclusion: According to our results, the microhardness of the evaluated conventional composite resins can withstand the masticatory forces; however nanohybrid composite resins showed better Vickers microhardness and therefore are a more clinically suitable option for minimal invasion treatments.

  6. Creep and creep-recovery of a thermoplastic resin and composite

    Science.gov (United States)

    Hiel, Clem

    1988-01-01

    The database on advanced thermoplastic composites, which is currently available to industry, contains little data on the creep and viscoelastic behavior. This behavior is nevertheless considered important, particularly for extended-service reliability in structural applications. The creep deformation of a specific thermoplastic resin and composite is reviewed. The problem to relate the data obtained on the resin to the data obtained on the composite is discussed.

  7. [Effect of bleaching agents on the color of indirect and direct composite resins].

    Science.gov (United States)

    Xing, Wenzhong; Jiang, Tao; Chen, Xiaodong; Wang, Yining

    2014-09-01

    To evaluate the effect of bleaching agents on the color of indirect and direct composite resins. Five resin composite materials were tested in this in vitro study. The five composites were as follow: two indirect composite resins (Adoro SR, Ceramage) and three direct composite resins (Filtek Z350, Clearfil Majesty Esthetic, and Gradia Direct Anterior). For each material, twenty disk-shaped specimens were prepared and randomly divided into five groups according to the color parameters of specimens before bleaching treatment. The composite resin specimens were treated by one of five sample solutions which were at-home bleaching agents (10% and 15% carbarmide peroxide), in- office bleaching agents (38% H(2)O(2) and 35%H(2)O(2)) and deionized water (control group). The color parameters of specimens were measured by spectrophotometer at baseline and after bleaching treatments. The color differences (ΔE values) between baseline and post-treatments were calculated. The data of color differences were evaluated statistically using two-way analysis with a significance level of 0.05. The color changes of the resin composites were less than 2.0 after bleaching agent treatment, therefore were not perceptible. Slight increase of L(*) values and decrease of C(*)ab values in color parameters of specimens were observed. There were statistically significant differences in ΔE values for different bleaching treatments and resin materials (P = 0.001). The bleaching agents did not affect the color of indirect and direct composite resins tested.

  8. New acrylic resin composite with improved thermal diffusivity.

    Science.gov (United States)

    Messersmith, P B; Obrez, A; Lindberg, S

    1998-03-01

    Studies have shown that physical characteristics of denture base materials may affect patient acceptance of denture prostheses by altering sensory experience of food during mastication. Thermal diffusivity is one material property that has been cited as being important in determining gustatory response, with denture base acrylic resins having low thermal diffusivity compared with denture base metal alloys. This study prepared and characterized experimental acrylic resin composite material with increased thermal diffusivity. Sapphire (Al2O3) whiskers were added to conventional denture base acrylic resin during processing to achieve loadings of 9.35% and 15% by volume. Cylindrical test specimens containing an embedded thermocouple were used to determine thermal diffusivity over a physiologic temperature range (0 degree to 70 degrees C). Thermal diffusivities of the sapphire containing composites were found to be significantly higher than the unmodified acrylic resin. Thermal diffusivity was found to increase in proportion to the volume percentage of sapphire filler, which suggested that the high aspect ratio ceramic particles formed a pathway for heat conduction through the insulating polymer matrix. The thermal diffusivity of denture base acrylic resin was increased by the addition of thermally conducting sapphire whiskers.

  9. Fracture strength and fatigue resistance of dental resin-based composites

    NARCIS (Netherlands)

    Keulemans, F.; Palav, P.; Aboushelib, M.M.N.; van Dalen, A.; Kleverlaan, C.J.; Feilzer, A.J.

    2009-01-01

    Objectives: The aim of this study was to evaluate in vitro the influence of fiber-reinforcement on the fracture strength and fatigue resistance of resin-based composites. Methods: One hundred rectangular bar-shaped specimens (2 mm × 2 mm × 25 mm) made of resin-based composite were prepared in a

  10. Effects of resin content and preparing conditions on the properties of polyphenylene sulfide resin/graphite composite for bipolar plate

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Li-gang; Li, Ai-ju; Yin, Qiang [Key Laboratory for Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Shandong Key Laboratory of Engineering Ceramics, Shandong University, Jinan 250061 (China); Wang, Wei-qiang [School of Mechanical Engineering, Shandong University, Jinan 250061 (China); Lin, Heng; Zhao, Yi-bo [School of Material Science and Engineering, Shandong University, Jinan 250061 (China)

    2008-03-15

    In the paper, a kind of polyphenylene sulfide (PPS) resin/graphite (G) composite for bipolar plate was prepared by using the PPS resin as adhesive and simple hot pressing. The influences of the resin content, the molding temperature and holding time on the conductivity and the bending strength of the PPS/G composite bipolar plate were investigated firstly and then the optimum content and the preparing conditions of the composite were obtained. The experimental results show that the electrical conductivity decreases and the bending strength reveals a serrated variation with increase in PPS resin content; when the holding time is certain, the conductivity decreases and the bending strength increases with the molding temperature increasing. The experimental results further show that the effect of the holding time on the properties of the composite is different at different molding temperatures. The PPS/G composite with 20% PPS resin content has electrical conductivity of 118.9 S cm{sup -1} and bending strength of 52.4 MPa when it molded at 380 C for 30 min, and has electrical conductivity of 105 S cm{sup -1}, bending strength of 55.7 MPa when it molded at 390 C for 30 min. The properties of the composites can meet the requirements of United States Department of Energy (DOE). (author)

  11. Antimicrobial and mechanical properties of dental resin composite containing bioactive glass.

    Science.gov (United States)

    Korkut, Emre; Torlak, Emrah; Altunsoy, Mustafa

    2016-07-26

    The aim of this study was to evaluate the antimicrobial efficacy and mechanical properties of dental resin composites containing different amounts of microparticulate bioactive glass (BAG). Experimental resin composites were prepared by mixing resin matrix (70% BisGMA and 30% TEGDMA) and inorganic filler with various fractions of BAG to achieve final BAG concentrations of 5, 10 and 30 wt%. Antimicrobial efficacy was assessed in aqueous suspension against Escherichia coli, Staphylococcus aureus and Streptococcus mutans and in biofilm against S. mutans. The effect of incorporation of BAG on the mechanical properties of resin composite was evaluated by measuring the surface roughness, compressive strength and flexural strength. Under the dynamic contact condition, viable counts of E. coli, S. aureus and S. mutans in suspensions were reduced up to 78%, 57% and 50%, respectively, after 90 minutes of exposure to disc-shaped composite specimens, depending on the BAG contents. In 2-day-old S. mutans biofilm, incorporation of BAG into composite at ratios of 10% and 30% resulted in 0.8 and 1.4 log reductions in the viable cell counts compared with the BAG-free composite, respectively. The surface roughness values of composite specimens did not show any significant difference (p>0.05) at any concentration of BAG. However, compressive and flexural strengths of composite were decreased significantly with addition of 30% BAG (p<0.05). The results demonstrated the successful utilization of BAG as a promising biomaterial in resin composites to provide antimicrobial function.

  12. Factors affecting marginal integrity of class II bulk-fill composite resin restorations

    Science.gov (United States)

    Savadi Oskoee, Siavash; Bahari, Mahmoud; Jafari Navimipour, Elmira; Ajami, Amir Ahmad; Ghiasvand, Negar; Savadi Oskoee, Ayda

    2017-01-01

    Background. Bulk-fill composite resins are a new type of resin-based composite resins, claimed to have the capacity to be placed in thick layers, up to 4 mm. This study was carried out to evaluate factors affecting gap formation in Cl II cavities restored using the bulk-fill technique. Methods. A total of 60 third molars were used in this study. Two Cl II cavities were prepared in each tooth, one on the mesial aspect 1 mm coronal to the CEJ and one on the distal aspect 1 mm apical to the CEJ. The teeth were divided into 4 groups: A: The cavities were restored using the bulk-fill technique with Filtek P90 composite resin and its adhesive system and light-cured with quartz tungsten halogen (QTH) light-curing unit. B: The cavities were restored similar to that in group A but light-cured with an LED light-curing unit. C: The cavities were restored using the bulk-fill technique with X-tra Fil composite resin and Clearfil SE Bond adhesive system and light-cured with a QTH curing unit. D: The cavities were restored similar to that in group C but light-cured with an LED light-curing unit. The gaps were examined under a stereomicroscope at ×60. Data were analyzed with General Linear Model test. In cases of statistical significance (Pcomposite resin type and margin location (Pcomposite resin type were not significant; however, the cumulative effect of composite rein type*gingival margin was significant (P=0.04) Conclusion. X-tra Fil composite exhibited smaller gaps compared with Filtek P90 composite with both light-curing units. Both composite resins exhibited smaller gaps at enamel margins. PMID:28748051

  13. Polymerization shrinkage stress of composite resins and resin cements – What do we need to know?

    Directory of Open Access Journals (Sweden)

    Carlos José SOARES

    2017-08-01

    Full Text Available Abstract Polymerization shrinkage stress of resin-based materials have been related to several unwanted clinical consequences, such as enamel crack propagation, cusp deflection, marginal and internal gaps, and decreased bond strength. Despite the absence of strong evidence relating polymerization shrinkage to secondary caries or fracture of posterior teeth, shrinkage stress has been associated with post-operative sensitivity and marginal stain. The latter is often erroneously used as a criterion for replacement of composite restorations. Therefore, an indirect correlation can emerge between shrinkage stress and the longevity of composite restorations or resin-bonded ceramic restorations. The relationship between shrinkage and stress can be best studied in laboratory experiments and a combination of various methodologies. The objective of this review article is to discuss the concept and consequences of polymerization shrinkage and shrinkage stress of composite resins and resin cements. Literature relating to polymerization shrinkage and shrinkage stress generation, research methodologies, and contributing factors are selected and reviewed. Clinical techniques that could reduce shrinkage stress and new developments on low-shrink dental materials are also discussed.

  14. Fiber-reinforced Composite Resin Prosthesis to Restore Missing ...

    African Journals Online (AJOL)

    A fiber-reinforced composite inlay-onlay FPD was used for a single posterior tooth replacement in a patient refusing implant for psychological reasons. The FRC-FPD was made of pre-impregnated E-glass fibers (everStick, StickTeck, Turku, Finland) embedded in a resin matrix (Stick Resin, StickTeck, Turku, Finland).

  15. Interactions between resin monomers and commercial composite resins with human saliva derived esterases.

    Science.gov (United States)

    Jaffer, F; Finer, Y; Santerre, J P

    2002-04-01

    Cholesterol esterase (CE) and pseudocholinesterase (PCE) have been reported to degrade commercial and model composite resins containing bisphenylglycidyl dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA) or the latter in combination with urethane modified BisGMA monomer systems. In addition, human saliva has been shown to contain esterase like activities similar to CE and PCE. Hence, it was the aim of the current study to determine to what extent human saliva could degrade two common commercial composite resins (Z250 from 3M Inc. and Spectrum TPH from L.D. Caulk) which contain the above monomer systems. Saliva samples from different volunteers were collected, processed, pooled, and freeze-dried. TEGDMA and BisGMA monomers were incubated with human saliva derived esterase activity (HSDEA) and their respective hydrolysis was monitored using high performance liquid chromatography (HPLC). Both monomers were completely hydrolyzed within 25 h by HSDEA. Photopolymerized composites were incubated with buffer or human saliva (pH 7.0 and 37 C) for 2, 8 and 16 days. The incubation solutions were analyzed using HPLC and mass spectrometry. Surface morphology characterization was carried out using scanning electron microscopy. Upon biodegradation, the Z250 composite yielded higher amounts of BisGMA and TEGDMA related products relative to the TPH composite. However, there were higher amounts of ethoxylated bis-phenol A released from the TPH material. In terms of total mass of products released, human saliva demonstrated a greater ability to degrade Z250. In summary, HSDEA has been shown to contain esterase activities that can readily catalyze the biodegradation of current commercial composite resins.

  16. Aerospace Composite Materials Delivery Order 0003: Nanocomposite Polymeric Resin Enhancements for Improved Composite Performance

    National Research Council Canada - National Science Library

    Chen, Chenggang

    2002-01-01

    .... The addition of clays does not significantly alter the viscosity or cure kinetics so that the modified resin will still be suitable for liquid composite molding techniques such as resin transfer molding...

  17. A review of devices used for photocuring resin-based composites.

    Science.gov (United States)

    Small, B W

    2001-01-01

    Composite resin shrinks up to 5% by volume upon curing. This shrinkage and the associated contraction stress remain the two most significant clinical problems with curing resin composite restorations. Many patients continue to experience sensitivity following placement of direct composites and seating of indirect restorations utilizing resin cements. Unfortunately, some claims made by manufacturers or certain clinicians that promise to alleviate these problems are made from a marketing standpoint, with no refereed literature to support those claims. Even within the literature, contradictory results have been reported, perpetuating the confusion. It is of utmost importance that all practicing dentists be aware of the various types of curing systems available and the advantages and disadvantages of each system. It is the opinion of the author that no existing system will alleviate every problem. Until new composite systems are perfected, such as the cyclopolymerizable resins and expanding polymers, we will continue to have shrinkage and stress. Be aware of false claims, read and interpret the literature, and, most importantly, do what is best for your patients.

  18. Fissure sealant materials: Wear resistance of flowable composite resins.

    Science.gov (United States)

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm(2) and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm(2)of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

  19. Ultraviolet light and ultraviolet light-activated composite resins

    International Nuclear Information System (INIS)

    Murray, G.A.; Yates, J.L.; Newman, S.M.

    1981-01-01

    In a comparison of the UV light--activated composite resins, Estilux was polymerized to a significantly greater depth than the other composite resins. In general, Lee-fill polymerized the least. When comparing the UV light sources, the Lee light and the Duralux light did not significantly differ from each other, but both polymerized the materials tested to a significantly greater depth than the other light sources. Of the two time exposures, 60-second exposure provided a significantly greater depth of polymerization than 20 seconds for each light with each material

  20. Effect of surface treatments on the bond strengths of facing composite resins to zirconia copings.

    Science.gov (United States)

    Tsumita, M; Kokubo, Y; Kano, T

    2012-09-01

    The present study evaluated and compared the bond strength between zirconia and facing composite resin using different surface conditioning methods before and after thermocycling. Four primers, three opaque resins, and two facing composite resins were used, and 10 surface treatment procedures were conducted. The bond strength was measured before and after 4,000 cycles of thermocycling. The mean values of each group were statistically analyzed using one-way analysis of variance (ANOVA). The bond strengths of facing composite resins to zirconia after various treatments varied depending on the primers, opaque resins, body resins, and thermocycling. The application of primers and opaque resins to the zirconia surface after sandblasting is expected to yield strong bond strength of the facing composite resin (Estenia CG&B) even after thermocycling.

  1. Surface roughness comparison of methacrylate and silorane-based composite resins after 40% hydrogen peroxide application

    Directory of Open Access Journals (Sweden)

    Rori Sasmita

    2018-01-01

    Full Text Available The change of the tooth colour could be restored with bleaching. The tooth bleaching will affects the surface roughness of the composite resins. Recently, the material basis for composite resins has developed, among others are methacrylate-based and silorane based composite resins. The objective of this study was to distinguish the surface roughness value of methacrylate-based composite resin and silorane based composite resins. This research was quasi-experimental. The sample used in this study were methacrylate and silorane based composite resins in discs form, with the size of 6 mm and the thickness of 3 mm, manufactured into 20 specimens and divided into 2 groups. The control group was immersed in the artificial saliva, and the treatment group was applied with 40% hydrogen peroxide. The result of the experiment analyzed using unpaired sample t-test showed significant differences in the average value of the surface roughness after the application of 40% hydrogen peroxide. The average value of methacrylate and silorane based composite resins were 2.744 μm and 3.417 μm, respectively. There was a difference in the surface roughness of methacrylate and silorane based composite resin compounds after the application of 40% hydrogen peroxide. The surface roughness value of the silorane-based composite resin was higher than the methacrylate-based.

  2. Polymerization Behavior and Mechanical Properties of High-Viscosity Bulk Fill and Low Shrinkage Resin Composites.

    Science.gov (United States)

    Shibasaki, S; Takamizawa, T; Nojiri, K; Imai, A; Tsujimoto, A; Endo, H; Suzuki, S; Suda, S; Barkmeier, W W; Latta, M A; Miyazaki, M

    The present study determined the mechanical properties and volumetric polymerization shrinkage of different categories of resin composite. Three high viscosity bulk fill resin composites were tested: Tetric EvoCeram Bulk Fill (TB, Ivoclar Vivadent), Filtek Bulk Fill posterior restorative (FB, 3M ESPE), and Sonic Fill (SF, Kerr Corp). Two low-shrinkage resin composites, Kalore (KL, GC Corp) and Filtek LS Posterior (LS, 3M ESPE), were used. Three conventional resin composites, Herculite Ultra (HU, Kerr Corp), Estelite ∑ Quick (EQ, Tokuyama Dental), and Filtek Supreme Ultra (SU, 3M ESPE), were used as comparison materials. Following ISO Specification 4049, six specimens for each resin composite were used to determine flexural strength, elastic modulus, and resilience. Volumetric polymerization shrinkage was determined using a water-filled dilatometer. Data were evaluated using analysis of variance followed by Tukey's honestly significant difference test (α=0.05). The flexural strength of the resin composites ranged from 115.4 to 148.1 MPa, the elastic modulus ranged from 5.6 to 13.4 GPa, and the resilience ranged from 0.70 to 1.0 MJ/m 3 . There were significant differences in flexural properties between the materials but no clear outliers. Volumetric changes as a function of time over a duration of 180 seconds depended on the type of resin composite. However, for all the resin composites, apart from LS, volumetric shrinkage began soon after the start of light irradiation, and a rapid decrease in volume during light irradiation followed by a slower decrease was observed. The low shrinkage resin composites KL and LS showed significantly lower volumetric shrinkage than the other tested materials at the measuring point of 180 seconds. In contrast, the three bulk fill resin composites showed higher volumetric change than the other resin composites. The findings from this study provide clinicians with valuable information regarding the mechanical properties and

  3. Depth of cure of bulk-fill flowable composite resins.

    Science.gov (United States)

    Pedalino, Inaam; Hartup, Grant R; Vandewalle, Kraig S

    2015-01-01

    In recent years, manufacturers have introduced flowable composite resins that reportedly can be placed in increments of 4 mm or greater. The purpose of this study was to evaluate the depth of cure of bulk-fill flowable composite resins (SureFil SDR Flow, Grandio Flow, and Venus Bulk Fill) and a conventional flowable composite resin (Revolution Formula 2). Depth of cure was measured in terms of bottom-maximum Knoop hardness number (KHN) ratios and the International Organization for Standardization (ISO) 4049 scrape technique. Shades A2 and A3 of SureFil SDR Flow, Grandio Flow, and Revolution Formula 2 were tested. Venus Bulk Fill was tested in its only available shade (universal). Specimens in thicknesses of 2, 3, 4, 5, and 6 mm were polymerized for 20 or 40 seconds, and a hardness tester was used to determine the hardness ratios for each shade at each thickness. For the scraping technique, after specimens were exposed to the curing light, unpolymerized composite resin was removed with a plastic instrument, the polymerized composite was measured, and the length was divided by 2 per ISO guidelines. According to the KHN ratios and the scrape test, Venus Bulk Fill predictably exceeded the manufacturer's claim of a 4-mm depth of cure at both 20 and 40 seconds of curing time. The overall results for depth of cure showed that Venus Bulk Fill ≥ SureFil SDR Flow ≥ Grandio Flow ≥ Revolution Formula 2.

  4. Structure-to-property relationships in addition cured polymers. II - Resin Tg and composite initial mechanical properties of norbornenyl cured polyimide resins

    Science.gov (United States)

    Alston, William B.

    1986-01-01

    PRM (polymerization of monomeric reactants) methodology was used to prepare thirty different polyimide oligomeric resins. Monomeric composition as well as chain length between sites of crosslinks were varied to examine their effects on glass transition temperature (Tg) of the cured/postcured resins. An almost linear correlation of Tg versus molecular distance between the crosslinks was observed. An attempt was made to correlate Tg with initial mechanical properties (flexural strength and interlaminar shear strength) of unidirectional graphite fiber composites prepared with these resins. However, the scatter in mechanical strength data prevented obtaining as clear a correlation as was observed for the structural modification/crosslink distance versus Tg. Instead, only a range of composite mechanical properties was obtained at the test temperatures studied (room temperature, 288 and 316 C). Perhaps more importantly, what did become apparent during the attempted correlation study was: (1) that PMR methodology could be used to prepare composites from resins that contain a wide variety of monomer modifications, and (2) that these composites almost invariably provided satisfactory initial mechanical properties as long as the resins selected were melt processable.

  5. Modeling and mechanical performance of carbon nanotube/epoxy resin composites

    International Nuclear Information System (INIS)

    Srivastava, Vijay Kumar

    2012-01-01

    Highlights: ► The MWCNT fillers are uniformly dispersed in the epoxy resin, which improved the mechanical properties of epoxy resin. ► Modified Halpin–Tsai model is useful to calculate the Young’s modulus of MWCNT/epoxy resin composite. ► The experimental moduli are within the variation of 27% with the theoretical values. -- Abstract: The effect of multi-walled carbon nanotube (MWCNT) addition on mechanical properties of epoxy resin was investigated to obtain the tensile strength, compressive strength and Young’s modulus from load versus displacement graphs. The result shows that the tensile strength, compressive strength and Young’s modulus of epoxy resin were increased with the addition of MWCNT fillers. The significant improvements in tensile strength, compressive strength and Young’s modulus were obtained due to the excellent dispersion of MWCNT fillers in the epoxy resin. The dispersion of MWCNT fillers in epoxy resin was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Also, Halpin–Tsai model was modified by considering the average diameter of internal/external of multi-walled nanotube and orientation factor (α) to calculate the Young’s modulus of multi-walled carbon nanotubes (MWCNTs)/epoxy resin composite. There was a good correlation between the experimentally obtained Young’s modulus and modified Halpin–Tsai model.

  6. Effect of sealant agents on the color stability and surface roughness of nanohybrid composite resins.

    Science.gov (United States)

    Dede, Doğu Ömür; Şahin, Onur; Koroglu, Aysegül; Yilmaz, Burak

    2016-07-01

    The effect of sealant agents on the surface roughness and color stability of nanohybrid composite resins is unknown. The purpose of this in vitro study was to evaluate the effect of sealant agents on the surface roughness and color stability of 4 nanohybrid composite resin materials. Forty disks (10×2 mm) were fabricated for each nanohybrid composite resin material (Z-550, Tetric EvoCeram, Clearfill Majesty, Ice) (N=160) and divided into 4 surface treatment groups: 1 conventional polishing (control) and 3 different sealant agent (Palaseal, Optiglaze, BisCover) coupling groups (n=10). The specimens were thermocycled, and surface roughness (Ra) values were obtained with a profilometer. Scanning electron microscope images were also recorded. CIELab color parameters of each specimen were measured with a spectrophotometer before and after 7 days of storage in a coffee solution. Color differences were calculated by the CIEDE 2000 (ΔE00) formula. The data were statistically analyzed by 2-way ANOVA and by the Tukey HSD test (α=.05). The surface treatment technique significantly affected the Ra values of the composite resins tested (Pcomposite resin material was also significant for ΔE00 values (Pcomposite resin groups, significant decreases in Ra were observed only for the Palaseal agent coupled composite resin groups (except Ice) compared with the control groups (Pcomposite resin group, except for BisCover applied Clearfill Majesty (Pcomposite resin groups, significant differences were observed between the color change seen with BisCover and other sealants for Clearfill Majesty composite resin (Pcomposite resins except for Ice produced smoother surfaces. All surface sealant agents provided less discoloration of nanohybrid composite resins after coffee staining compared with conventional polishing except for BisCover applied Clearfill Majesty composite resin. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All

  7. Perlekatan koloni Streptococcus mutans pada permukaan resin komposit sinar tampak (The adherence of Streptococcus mutans colony to surface visible light composite resins

    Directory of Open Access Journals (Sweden)

    Ajeng Anggraeni

    2005-03-01

    Full Text Available Visible light composite resins was used to restore anterior and posterior teeth, and it is always covered by saliva pellicle. S. mutans can adhere to all of the surface of oral cavity and visible light composite resins. The aim of this study was to know the amount of S. mutans colony adherence to visible light composite resins surface. The sample of 5 mm diameter and 3 mm in thickness was immersed in saliva for one hour, than the samples were put into bacteria suspension, incubated for 24 hours at 37° C. The amount of S. mutans was determined by direct count using microscope. The data were statistically analyzed by using t test. The result showed a significance difference of S. mutans colony between hybrid and micro fill visible light composite resins. The conclusion was that the amount of S. mutans adherence on the surface of hybrid was higher than the micro fill visible light composite resins.

  8. Grinding efficiency of abutment tooth with both dentin and core composite resin on axial plane.

    Science.gov (United States)

    Miho, Otoaki; Sato, Toru; Matsukubo, Takashi

    2015-01-01

    The purpose of this study was to evaluate grinding efficiency in abutment teeth comprising both dentin and core composite resin in the axial plane. Grinding was performed over 5 runs at two loads (0.5 or 0.25 N) and two feed rates (1 or 2 mm/sec). The grinding surface was observed with a 3-D laser microscope. Tomographic images of the grinding surfaces captured perpendicular to the feed direction were also analyzed. Using a non-ground surface as a reference, areas comprising only dentin, both dentin and core composite resin, or only core composite resin were analyzed to determine the angle of the grinding surface. Composite resins were subjected to the Vickers hardness test and scanning electron microscopy. Data were statistically analyzed using a one-way analysis of variance and multiple comparison tests. Multiple regression analysis was performed for load, feed rate, and Vickers hardness of the build-up material depending on number of runs. When grinding was performed at a constant load and feed rate, a greater grinding angle was observed in areas comprising both dentin and composite resin or only composite resin than in areas consisting of dentin alone. A correlation was found between machinability and load or feed rate in areas comprising both dentin and composite resin or composite resin alone, with a particularly high correlation being observed between machinability and load. These results suggest that great caution should be exercised in a clinical setting when the boundary between the dentin and composite resin is to be ground, as the angle of the grinding surface changes when the rotating diamond point begins grinding the composite resin.

  9. Synthesis of a magnetic composite resin and its cobalt removal characteristics in aqueous solution

    International Nuclear Information System (INIS)

    Kim, Young Kyun; Lee, Kun Jai

    2001-01-01

    A series of stepwise procedures to prepare a new organic-inorganic composite magnetic resin with phenolsulphonic-formaldehyde and freshly formed iron ferrite was established, based upon wet-and-neutralization method for synthesizing iron ferrite and pearl-polymerization method for synthesizing rigid bead-type composite resin. The ion exchange and sorption characteristics of the composite resin prepared by the above method at various conditions were experimentally disclosed. The composite resin prepared shows stably high removal efficiency to Co(II) species in aqueous solution in a wide range of solution pH. The overall isotherm is qualitatively explained by the generalized adsorption isotherm concept proposed by McKinley. The standard enthalpy change derived from van't Hoff equation conforms to the typical range for chemisorption or ion exchange. The selectivity of the PSF-F (phenolsulphonic formaldehyde-iron ferrite) composite resin to Co(II) species and other competing chemicals (i.e. Na 2 EDTA, Ca(II) and Na) was compared. It is anticipated that the composite resin can also be used for column-operation with process-control by applying external magnetic field, since the rigid bead-type composite resin shows magnetic-susceptibility due to its paramagnetic inorganic constituent (i.e. iron ferrite). (author)

  10. Effect of in-office bleaching agents on physical properties of dental composite resins.

    Science.gov (United States)

    Mourouzis, Petros; Koulaouzidou, Elisabeth A; Helvatjoglu-Antoniades, Maria

    2013-04-01

    The physical properties of dental restorative materials have a crucial effect on the longevity of restorations and moreover on the esthetic demands of patients, but they may be compromised by bleaching treatments. The purpose of this study was to evaluate the effects of in-office bleaching agents on the physical properties of three composite resin restorative materials. The bleaching agents used were hydrogen peroxide and carbamide peroxide at high concentrations. Specimens of each material were prepared, cured, and polished. Measurements of color difference, microhardness, and surface roughness were recorded before and after bleaching and data were examined statistically by analysis of variance (ANOVA) and Tukey HSD post-hoc test at P composite resin altered after the bleaching procedure (P composite resins tested (P > .05). The silorane-based composite resin tested showed some color alteration after bleaching procedures. The bleaching procedure did not alter the microhardness and the surface roughness of all composite resins tested.

  11. Physicochemical properties of discontinuous S2-glass fiber reinforced resin composite.

    Science.gov (United States)

    Huang, Qiting; Qin, Wei; Garoushi, Sufyan; He, Jingwei; Lin, Zhengmei; Liu, Fang; Vallittu, Pekka K; Lassila, Lippo V J

    2018-01-30

    The objective of this study was to investigate several physicochemical properties of an experimental discontinuous S2-glass fiber-reinforced resin composite. The experimental composite was prepared by mixing 10 wt% of discontinuous S2-glass fibers with 27.5 wt% of resin matrix and 62.5 wt% of particulate fillers. Flexural strength (FS) and modulus (FM), fracture toughness (FT), work of fracture (WOF), double bond conversion (DC), Vickers hardness, volume shrinkage (VS) and fiber length distribution were determined. These were compared with two commercial resin composites. The experimental composite showed the highest FS, WOF and FT compared with two control composites. The DC of the experimental composite was comparable with controls. No significant difference was observed in VS between the three tested composites. The use of discontinuous glass fiber fillers with polymer matrix and particulate fillers yielded improved physical properties and substantial improvement was associated with the use of S2-glass fiber.

  12. Effect of light-curing units on microleakage under dental composite resins

    Science.gov (United States)

    Queiroz, R. S.; Bandéca, M. C.; Calixto, L. R.; Saade, E. G.; Nadalin, M. R.; Andrade, M. F.; Porto-Neto, S. T.

    2009-09-01

    The aim of this study was to determine the effect of two light-curing units (QTH and LED) on microleakage of Class II composite resin restorations with dentin cavosurface margins. Twenty extracted mandibular first premolars, free of caries and fractures were prepared two vertical “slot” cavities in the occluso-mesial and -destal surfaces (2 mm buccal-lingually, 2 mm proximal-axially and cervical limit in enamel) and divided into 4 equal groups ( n = 8): GI and GII: packable posterior composite light-activated with LED and QTH, respectively; GIII and GIV: micro-hybrid composite resin light-activated with LED and QTH, respectively. The composite resins were applied following the manufacturer’s instructions. After 24 h of water storage specimens were subjected to thermocycling for a total of 500 cycles at 5 and 55°C and the teeth were then sealed with impermeable material. Teeth were immersed in 0.5% Basic fuchsin during 24 h at room temperature, and zero to three levels of penetration score were attributed. The Mann-Whitney and Kruskal-Wallis tests showed significant statistically similar ( P > 0.05) from GI to GII and GIII to GIV, which the GII (2.750) had the highest mean scores and the GIII and GIV (0.875) had lowest mean scores. The use of different light-curing units has no influence on marginal integrity of Class II composite resin restorations and the proprieties of composite resins are important to reduce the microleakage.

  13. Bulk-fill resin composites: polymerization contraction, depth of cure, and gap formation.

    Science.gov (United States)

    Benetti, A R; Havndrup-Pedersen, C; Honoré, D; Pedersen, M K; Pallesen, U

    2015-01-01

    The bulk-filling of deep, wide dental cavities is faster and easier than traditional incremental restoration. However, the extent of cure at the bottom of the restoration should be carefully examined in combination with the polymerization contraction and gap formation that occur during the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk-fill materials produced a significantly larger depth of cure and polymerization contraction. Although most of the bulk-fill materials exhibited a gap formation similar to that of the conventional resin composite, two of the low-viscosity bulk-fill resin composites, x-tra base and Venus Bulk Fill, produced larger gaps.

  14. Properties of discontinuous S2-glass fiber-particulate-reinforced resin composites with two different fiber length distributions.

    Science.gov (United States)

    Huang, Qiting; Garoushi, Sufyan; Lin, Zhengmei; He, Jingwei; Qin, Wei; Liu, Fang; Vallittu, Pekka Kalevi; Lassila, Lippo Veli Juhana

    2017-10-01

    To investigate the reinforcing efficiency and light curing properties of discontinuous S2-glass fiber-particulate reinforced resin composite and to examine length distribution of discontinuous S2-glass fibers after a mixing process into resin composite. Experimental S2-glass fiber-particulate reinforced resin composites were prepared by mixing 10wt% of discontinuous S2-glass fibers, which had been manually cut into two different lengths (1.5 and 3.0mm), with various weight ratios of dimethacrylate based resin matrix and silaned BaAlSiO 2 filler particulates. The resin composite made with 25wt% of UDMA/SR833s resin system and 75wt% of silaned BaAlSiO 2 filler particulates was used as control composite which had similar composition as the commonly used resin composites. Flexural strength (FS), flexural modulus (FM) and work of fracture (WOF) were measured. Fractured specimens were observed by scanning electron microscopy. Double bond conversion (DC) and fiber length distribution were also studied. Reinforcement of resin composites with discontinuous S2-glass fibers can significantly increase the FS, FM and WOF of resin composites over the control. The fibers from the mixed resin composites showed great variation in final fiber length. The mean aspect ratio of experimental composites containing 62.5wt% of particulate fillers and 10wt% of 1.5 or 3.0mm cutting S2-glass fibers was 70 and 132, respectively. No difference was found in DC between resin composites containing S2-glass fibers with two different cutting lengths. Discontinuous S2-glass fibers can effectively reinforce the particulate-filled resin composite and thus may be potential to manufacture resin composites for high-stress bearing application. Copyright © 2017. Published by Elsevier Ltd.

  15. Preparation and Electrochemical Properties of Graphene/Epoxy Resin Composite Coating

    Science.gov (United States)

    Liao, Zijun; Zhang, Tianchi; Qiao, Sen; Zhang, Luyihang

    2017-11-01

    The multilayer graphene powder as filler, epoxy modified silicone resin as film-forming agent, anticorrosion composite coating has been created using sand dispersion method, the electrochemical performance was compared with different content of graphene composite coating and pure epoxy resin coating. The open circuit potential (OCP), potentiodynamic polarization curves (Tafel Plot) and electrochemical impedance spectroscopy (EIS) were tested. The test results showed that the anti-corrosion performance of multilayer graphene added has improved greatly, and the content of the 5% best corrosion performance of graphene composite coating.

  16. Microhardness of dual-polymerizing resin cements and foundation composite resins for luting fiber-reinforced posts.

    Science.gov (United States)

    Yoshida, Keiichi; Meng, Xiangfeng

    2014-06-01

    The optimal luting material for fiber-reinforced posts to ensure the longevity of foundation restorations remains undetermined. The purpose of this study was to evaluate the suitability of 3 dual-polymerizing resin cements and 2 dual-polymerizing foundation composite resins for luting fiber-reinforced posts by assessing their Knoop hardness number. Five specimens of dual-polymerizing resin cements (SA Cement Automix, G-Cem LincAce, and Panavia F2.0) and 5 specimens of dual-polymerizing foundation composite resins (Clearfil DC Core Plus and Unifil Core EM) were polymerized from the top by irradiation for 40 seconds. Knoop hardness numbers were measured at depths of 0.5, 2.0, 4.0, 6.0, 8.0, and 10.0 mm at 0.5 hours and 7 days after irradiation. Data were statistically analyzed by repeated measures ANOVA, 1-way ANOVA, and the Tukey compromise post hoc test (α=.05). At both times after irradiation, the 5 resins materials showed the highest Knoop hardness numbers at the 0.5-mm depth. At 7 days after irradiation, the Knoop hardness numbers of the resin materials did not differ significantly between the 8.0-mm and 10.0-mm depths (P>.05). For all materials, the Knoop hardness numbers at 7 days after irradiation were significantly higher than those at 0.5 hours after irradiation at all depths (Presin materials were found to decrease in the following order: DC Core Plus, Unifil Core EM, Panavia F2.0, SA Cement Automix, and G-Cem LincAce (Pcomposite resins were higher than those of the 3 dual-polymerizing resin cements, notable differences were seen among the 5 materials at all depths and at both times after irradiation. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  17. Silicone Resin Applications for Ceramic Precursors and Composites

    Directory of Open Access Journals (Sweden)

    Masaki Narisawa

    2010-06-01

    Full Text Available This article reviews the applications of silicone resins as ceramic precursors. The historical background of silicone synthesis chemistry is introduced to explain the production costs and supply availability of various silicones. Thermal degradation processes of silicones are classified in terms of the main chain structure and cyclic oligomer expulsion process, which determine the resulting ceramic yield and the chemical composition. The high temperature decomposition of Si-O-C beyond 1,400 °C in an inert atmosphere and formation of a protective silica layer on material surfaces beyond 1,200 °C in an oxidative atmosphere are discussed from the viewpoints of the wide chemical composition of the Si-O-C materials. Applications of the resins for binding agents, as starting materials for porous ceramics, matrix sources with impregnation, fiber spinning and ceramic adhesions are introduced. The recent development of the process of filler or cross-linking agent additions to resin compounds is also introduced. Such resin compounds are useful for obtaining thick coatings, MEMS parts and bulk ceramics, which are difficult to obtain by pyrolysis of simple organometallic precursors without additives.

  18. Evaluating resin-enamel bonds by microshear and microtensile bond strength tests: effects of composite resin

    Directory of Open Access Journals (Sweden)

    Andrea Mello de Andrade

    2010-12-01

    Full Text Available OBJECTIVES: The aims of this study were to evaluate the effect of resin composite (Filtek Z250 and Filtek Flow Z350 and adhesive system [(Solobond Plus, Futurabond NR (VOCO and Adper Single Bond (3M ESPE] on the microtensile (μTBS and microshear bond strength (μSBS tests on enamel, and to correlate the bond strength means between them. MATERIAL AND METHODS: Thirty-six extracted human molars were sectioned to obtain two tooth halves: one for μTBS and the other one for μSBS. Adhesive systems and resin composites were applied to the enamel ground surfaces and light-cured. After storage (37(0C/24 h specimens were stressed (0.5 mm/min. Fracture modes were analyzed under scanning electron microscopy. The data were analyzed using two-way ANOVA and Tukey's test (α=0.05. RESULTS: The correlation between tests was estimated with Pearson's product-moment correlation statistics (α =0.05. For both tests only the main factor resin composite was statistically significant (p<0.05. The correlation test detected a positive (r=0.91 and significant (p=0.01 correlation between the tests. CONCLUSIONS: The results were more influenced by the resin type than by the adhesives. Both microbond tests seem to be positive and linearly correlated and can therefore lead to similar conclusions.

  19. Characterization of Composite Fan Case Resins

    Science.gov (United States)

    Dvoracek, Charlene M.

    2004-01-01

    The majority of commercial turbine engines that power today s aircraft use a large fan driven by the engine core to generate thrust which dramatically increases the engine s efficiency. However, if one of these fan blades fails during flight, it becomes high energy shrapnel, potentially impacting the engine or puncturing the aircraft itself and thus risking the lives of passengers. To solve this problem, the fan case must be capable of containing a fan blade should it break off during flight. Currently, all commercial fan cases are made of either just a thick metal barrier or a thinner metal wall surrounded by Kevlar-an ultra strong fiber that elastically catches the blade. My summer 2004 project was to characterize the resins for a composite fan case that will be lighter and more efficient than the current metal. The composite fan case is created by braiding carbon fibers and injecting a polymer resin into the braid. The resin holds the fibers together, so at first using the strongest polymer appears to logically lead to the strongest fan case. Unfortunately, the stronger polymers are too viscous when melted. This makes the manufacturing process more difficult because the polymer does not flow as freely through the braid, and the final product is less dense. With all of this in mind, it is important to remember that the strength of the polymer is still imperative; the case must still contain blades with high impact energy. The research identified which polymer had the right balance of properties, including ease of fabrication, toughness, and ability to transfer the load to the carbon fibers. Resin deformation was studied to better understand the composite response during high speed impact. My role in this research was the testing of polymers using dynamic mechanical analysis and tensile, compression, and torsion testing. Dynamic mechanical analysis examines the response of materials under cyclic loading. Two techniques were used for dynamic mechanical analysis

  20. Profile of Fluoride Release from a Nanohybrid Composite Resin

    Directory of Open Access Journals (Sweden)

    Raquel Assed Bezerra Silva

    2015-02-01

    Full Text Available The aim of this study was to evaluate in vitro the amount and profile of fluoride release from a fluoride-containing nanohybrid composite resin (Tetric® N-Ceram by direct potentiometry. Thirty specimens (5 mm diameter x 3 mm high; n=10/material were made of Tetric® N-Ceram, Vitremer® resin-modified glass ionomer cement (RMGIC (positive control or Filtek® Z350 nanofill composite resin (negative control. The specimens were stored individually in plastic tubes containing 1 mL of artificial saliva at 37°C, which was daily renewed during 15 days. At each renewal of saliva, the amount of fluoride ions released in the solution was measured using a fluoride ion-selective electrode with ion analyzer, and the values obtained in mV were converted to ppm (µg/mL. Data were analyzed statistically by ANOVA and Tukey’s post-hoc test at a significance level of 5%. The results showed that the resins Tetric® N-Ceram and Filtek® Z350 did not release significant amounts of fluoride during the whole period of evaluation (p>0.05. Only Vitremer® released significant amounts of fluoride ions during the 15 days of the experiment, with greater release in first 2 days (p0.05. In conclusion, the nanohybrid composite resin Tetric® N-Ceram did not present in vitro fluoride-releasing capacity throughout the 15 days of study.

  1. Effects of toothbrush hardness on in vitro wear and roughness of composite resins.

    Science.gov (United States)

    Kyoizumi, Hideaki; Yamada, Junji; Suzuki, Toshimitsu; Kanehira, Masafumi; Finger, Werner J; Sasaki, Keiichi

    2013-11-01

    To investigate and compare the effects of toothbrushes with different hardness on abrasion and surface roughness of composite resins. Toothbrushes (DENT. EX Slimhead II 33, Lion Dental Products Co. Ltd., Tokyo, Japan) marked as soft, medium and hard, were used to brush 10 beam-shaped specimens of each of three composites resins (Venus [VEN], Venus Diamond [VED] and Venus Pearl [VEP]; HeraeusKulzer) with standardized calcium carbonate slurry in a multistation testing machine (2N load, 60 Hz). After each of five cycles with 10k brushing strokes the wear depth and surface roughness of the specimens were determined. After completion of 50k strokes representative samples were inspected by SEM. Data were treated with ANOVA and regression analyses (p composite resins increased linearly with increasing number of brushing cycles (r² > 0.9). Highest wear was recorded for VEN, lowest for VED. Hard brushes produced significantly higher wear on VEN and VEP, whereas no difference in wear by toothbrush type was detected for VED. Significantly highest surface roughness was found on VED specimens (Ra > 1.5 µm), the lowest one on VEN (Ra composite resins produced by toothbrushing with dentifrice depend mainly on the type of restorative resin. Hardness grades of toothbrushes have minor effects only on abrasion and surface roughness of composite resins. No relationship was found between abrasion and surface roughness. The grade of the toothbrush used has minor effect on wear, texture and roughness of the composite resin.

  2. Research and Development Progress of National Key Laboratory of Advanced Composites on Advanced Aeronautical Resin Matrix Composites

    Directory of Open Access Journals (Sweden)

    LI Bintai

    2016-06-01

    Full Text Available Applications and research progress in advanced aeronautical resin matrix composites by National Key Laboratory of Advanced Composites (LAC were summarized. A novel interlaminar toughening technology employing ultra-thin TP non-woven fabric was developed in LAC, which significantly improved the compression after impact (CAI performances of composite laminates.Newly designed multilayer sandwich stealth composite structures exhibited a good broadband radar absorbing properties at 1-18 GHz.There were remarkable developments in high toughness and high temperature resin matrix composites, covering major composite processing technologies such as prepreg-autoclave procedure, liquid composite molding and automation manufacture, etc. Finally, numerical simulation and optimization methods were deliberately utilized in the study of composites curing behavior, resin flow and curing deformation. A composite material database was also established.In conclusion, LAC has been a great support for the development of aeronautical equipment, playing such roles as innovation leading, system dominating, foundation supporting and application ensuring of aerocomposites.

  3. In vitro enamel remineralization capacity of composite resins containing sodium trimetaphosphate and fluoride.

    Science.gov (United States)

    Tiveron, Adelisa Rodolfo Ferreira; Delbem, Alberto Carlos Botazzo; Gaban, Gabriel; Sassaki, Kikue Takebayashi; Pedrini, Denise

    2015-11-01

    This study evaluated the in vitro enamel remineralization capacity of experimental composite resins containing sodium trimetaphosphate (TMP) combined or not with fluoride (F). Bovine enamel slabs were selected upon analysis of initial surface hardness (SH1) and after induction of artificial carious lesions (SH2). Experimental resins were as follows: resin C (control—no sodium fluoride (NaF) or TMP), resin F (with 1.6% NaF), resin TMP (with 14.1% TMP), and resin TMP/F (with NaF and TMP). Resin samples were made and attached to enamel slabs (n = 12 slabs per material). Those specimens (resin/enamel slab) were subjected to pH cycling to promote remineralization, and then final surface hardness (SH3) was measured to calculate the percentage of surface hardness recovery (%SH). The integrated recovery of subsurface hardness (ΔKHN) and F concentration in enamel were also determined. Data was analyzed by ANOVA and Student-Newman-Keuls test (p Resins F and TMP/F showed similar SH3 values (p = 0.478) and %SH (p = 0.336) and differed significantly from the other resins (p resin TMP/F presented the lowest area of lesion (p resins (p = 0.042), but higher than in the other resins (p composite resin enhanced its capacity for remineralization of enamel in vitro. The combination of two agents with action on enamel favored remineralization, suggesting that composite resins containing sodium trimetaphosphate and fluoride could be indicated for clinical procedures in situations with higher cariogenic challenges.

  4. Cuspal Deflection of Premolars Restored with Bulk-Fill Composite Resins.

    Science.gov (United States)

    Behery, Haytham; El-Mowafy, Omar; El-Badrawy, Wafa; Saleh, Belal; Nabih, Sameh

    2016-01-01

    This in vitro study compared cuspal deflection of premolars restored with three bulk-fill composite resins to that of incrementally-restored ones with a low-shrinkage silorane-based restorative material. Forty freshly-extracted intact human upper premolars were used. Reference points at buccal and palatal cusp tips were acid-etched and composite rods were horizontally bonded to them (TPH-Spectra-HV, Dentsply). Two acrylic resin guiding paths were made for each premolar to guide beaks of a digital micrometer used for cuspal deflection measurements. Standardized MOD cavities, 3 mm wide bucco-lingually and 3.5 mm deep, were prepared on each premolar. Prepared teeth were then equally divided into four groups (n = 10) and each group was assigned to one of four composite resin (QuiXX, Dentsply; X-tra fil, Voco; Tetric EvoCeram Bulk Fill, Ivoclar Vivadent; low-shrinkage Filtek LS, 3M/ESPE). Adper Single Bond-Plus, 3M/ESPE was used with all bulk-fill restoratives. LS-System Adhesive, 3M/ESPE was used with Filtek LS. For each prepared premolar, cuspal deflection was measured in microns as the difference between two readings between reference points before and after restoration completion. Means and SDs were calculated and data statistically-analyzed using One-way ANOVA and Tukey's test. Filtek LS showed the lowest mean cuspal deflection value 6.4(0.84)μm followed by Tetric EvoCeram Bulk Fill 10.1(1.2) μm and X-tra fil 12.4(1.35)μm, while QuiXX showed the highest mean 13(1.05)μm. ANOVA indicated significant difference among mean values of groups (p composite resins tested. Filtek LS had the lowest significant mean cuspal deflection in comparison to all tested bulk-fill restoratives. The use of Tetric EvoCeram Bulk fill composite resin restorative for class II MOD cavities resulted in reduced cuspal deflection in comparison to the two other bulk-fill composite resins tested. The silorane-based Filtek LS restorative resulted in the least cuspal deflection in

  5. [Influences of composition on brush wear of composite resins. Influences of particle size and content of filler].

    Science.gov (United States)

    Yuasa, S

    1990-07-01

    The influences of the composition on abrasion resistance of composite resins were examined using various experimental composite resins which had various matrix resin, filler size and content. The abrasion test was conducted by the experimental toothbrush abrasion testing machine developed in our laboratory. Three series of heat-curing composite resins were tested. One series was made from a Bis-MPEPP or UDMA monomer, and a silica filler with an average particle size of 0.04, 1.9, 3.8, 4.3, 7.5, 13.8 and 14.1 microns. The filler content of this series was constant at 45 wt%. The second series contained a silica filler of 4.3 microns in a content ranging from 35 to 75 wt%. The third series contained a microfiller (0.04 microns) and macrofiller (4.3 microns) in total content of 45 wt%. In this series, the microfiller was gradually replaced by 5, 15, 25 and 45 wt% of the macrofiller. The results obtained for these three series indicated that the abrasion resistance of composite resins was controlled by the inorganic filler, mainly filler size and content. The abrasion loss did not vary with the difference of matrix resin. When the particle size of the filler was below about 5 microns, the abrasion resistance decreased markedly with the decrease in filler size. The composite resin which contained a 0.04 or 1.9 micron filler was less resistant to toothbrush wear than the unfilled matrix resin. However, the microfiller also contributed to abrasion resistance when used in combination with the macrofiller, although abrasion resistance decreased with the increase in the microfiller concentration. The increase of filler content clearly improved the abrasion resistance when used the macrofiller. The analysis of these results and SEM observations of the brushed surfaces of samples suggested that the toothbrush abrasion was three-body abrasion caused by the abrasive in the toothpaste, and affected by the difference in the particle size between abrasive and filler, and between

  6. Effect of Ingested Liquids on Color Change of Composite Resins.

    Science.gov (United States)

    Malek Afzali, Beheshteh; Ghasemi, Amir; Mirani, Asrin; Abdolazimi, Zahra; Akbarzade Baghban, Alireza; Kharazifard, Mohammad Javad

    2015-08-01

    Color change of composite restorations is well known to dentists. However, the effect of commonly consumed drinks on discoloration of composite resins has yet to be determined. This study sought to assess the color change of a nanofilled (Premise) and a flowable composite resin (Premise flowable) following simulated consumption of tea, cola, iron drops and multivitamin syrup. Forty disk-shaped specimens (7 mm in diameter and 2 mm thick) were fabricated from each composite resin. The baseline color values were measured according to the CIE L*a*b* system using digital imaging. The specimens of each restorative material were randomly divided into five groups (eight each) according to the storage media namely tea, cola, iron drops, multivitamin syrup or distilled water (control). The specimens were immersed in staining solutions for three hours daily over a 40-day test period. Following this, the color change values (ΔE*) were calculated. For statistical analyses, the color differences were analyzed using two-way ANOVA and Tukey's test (Pcomposite resins (P>0.05). In both composite materials, the difference among the solutions was not significant (P>0.05). Under the tested experimental conditions, both restorative materials were susceptible to discoloration by all four staining solutions. The color change values were not related to the solution or the type of material used.

  7. Novel matrix resins for composites for aircraft primary structures, phase 1

    Science.gov (United States)

    Woo, Edmund P.; Puckett, P. M.; Maynard, S.; Bishop, M. T.; Bruza, K. J.; Godschalx, J. P.; Mullins, M. J.

    1992-01-01

    The objective of the contract is the development of matrix resins with improved processability and properties for composites for primarily aircraft structures. To this end, several resins/systems were identified for subsonic and supersonic applications. For subsonic aircraft, a series of epoxy resins suitable for RTM and powder prepreg was shown to give composites with about 40 ksi compressive strength after impact (CAI) and 200 F/wet mechanical performance. For supersonic applications, a thermoplastic toughened cyanate prepreg system has demonstrated excellent resistance to heat aging at 360 F for 4000 hours, 40 ksi CAI and useful mechanical properties at greater than or equal to 310 F. An AB-BCB-maleimide resin was identified as a leading candidate for the HSCT. Composite panels fabricated by RTM show CAI of approximately 50 ksi, 350 F/wet performance and excellent retention of mechanical properties after aging at 400 F for 4000 hours.

  8. Inhibitory effect on Streptococcus mutans and mechanical properties of the chitosan containing composite resin

    Directory of Open Access Journals (Sweden)

    Ji-Sun Kim

    2013-02-01

    Full Text Available Objectives This study evaluated the antibacterial effect and mechanical properties of composite resins (LCR, MCR, HCR incorporating chitosan with three different molecular weights (L, Low; M, Medium; H, High. Materials and Methods Streptococcus (S. mutans 100 mL and each chitosan powder were inoculated in sterilized 10 mL Brain-Heart Infusion (BHI solution, and was centrifuged for 12 hr. Absorbance of the supernatent was measured at OD660 to estimate the antibacterial activities of chitosan. After S. mutans was inoculated in the disc shaped chitosan-containing composite resins, the disc was cleansed with BHI and diluted with serial dilution method. S. mutans was spread on Mitis-salivarius bacitracin agar. After then, colony forming unit (CFU was measured to verify the inhibitory effect on S. mutans biofilm. To ascertain the effect on the mechanical properties of composite resin, 3-point bending and Vickers hardness tests were done after 1 and 3 wk water storage, respectively. Using 2-way analysis of variance (ANOVA and Scheffe test, statistical analysis was done with 95% significance level. Results All chitosan powder showed inhibition effect against S. mutans. CFU number in chitosan-containing composite resins was smaller than that of control resin without chitosan. The chitosan containing composite resins did not show any significant difference in flexural strength and Vickers hardness in comparison with the control resin. However, the composite resin, MCR showed a slightly decreased flexural strength and the maximum load than those of control and the other composite resins HCR and LCR. Conclusions LCR and HCR would be recommended as a feasible antibacterial restorative due to its antibacterial nature and mechanical properties.

  9. Maleimido substituted cyclotriphosphazene resins for fire and heat resistant composites

    Science.gov (United States)

    Kumar, D.; Fohlen, G. M.; Parker, J. A.

    1983-01-01

    A new class of fire- and heat-resistant matrix resins have been synthesized by the thermal polymerization of maleimido substituted phenoxycyclotriphosphazenes. The resins have exhibited a char yield of 82 percent at 800 C in nitrogen and 81 percent at 700 C in air. Graphite-fabric laminates based on a resin of this class have shown a limiting oxygen index of 100 percent even at 300 C. Details of the fabrication of the resins and the composites and testing procedures are discussed.

  10. A medicated polycarboxylate cement to prevent complications in composite resin therapy

    International Nuclear Information System (INIS)

    Okamoto, Y.; Shintani, H.; Yamaki, M.

    1990-01-01

    Preparative treatment is the preferred method to protect the dentin and pulp from complications in composite resin therapy. This study investigated the in vivo effects of the polycarboxylate cement containing zinc fluoride and tannic acid in composite resin restorations. Scanning electron micrographs established that the composite resin failed to contact the axial wall. The gaps varied from 10 to 60 microns. However, this polycarboxylate cement was shown to provide excellent adaptation to dentin when used as a base and its chemical adhesion allowed it to make close contact with the unetched dentin. The newly developed electron probe x-ray microanalyzer revealed that the in vivo penetration of fluoride and zinc occurred through the dentinal tubules. When this polycarboxylate cement was used, the orifices of dentinal tubules were partially occluded, possibly with the smear layer fixed by tannic acid. In addition, by releasing the components, this polycarboxylate cement adds acid resistance to dentin and increases the resistance of dentin collagen to proteolytic enzymes. As such this polycarboxylate cement offers advantages as a base to composite resin therapy

  11. Composite Properties of Polyimide Resins Made From "Salt-Like" Solution Precursors

    Science.gov (United States)

    Cano, Roberto J.; Weiser, Erik S.; SaintClair, Terry L.; Echigo, Yoshiaki; Kaneshiro, Hisayasu

    1997-01-01

    Recent work in high temperature materials at NASA Langley Research Center (LaRC (trademark)) have led to the development of new polyimide resin systems with very attractive properties. The majority of the work done with these resin systems has concentrated on determining engineering mechanical properties of composites prepared from a poly(amide acid) precursor. Three NASA Langley-developed polyimide matrix resins, LaRC (trademark) -IA, LaRC (trademark) -IAX, and LaRC (trademark) -8515, were produced via a salt-like process developed by Unitika Ltd. The 'salt-like' solutions (sixty-five percent solids in NMP) were prepregged onto Hexcel IM7 carbon fiber using the NASA LaRC Multipurpose Tape Machine. Process parameters were determined and composite panels fabricated. Mechanical properties are presented for these three intermediate modulus carbon fiber/polyimide matrix composites and compared to existing data on the same polyimide resin systems and IM7 carbon fiber manufactured via poly(amide acid) solutions (thirty-five percent solids in NMP). This work studies the effects of varying the synthetic route on the processing and mechanical properties of polyimide composites.

  12. Surface Roughness of Composite Resins after Simulated Toothbrushing with Different Dentifrices.

    Science.gov (United States)

    Monteiro, Bruna; Spohr, Ana Maria

    2015-07-01

    The aim of the study was to evaluate, in vitro, the surface roughness of two composite resins submitted to simulated toothbrushing with three different dentifrices. Totally, 36 samples of Z350XT and 36 samples of Empress Direct were built and randomly divided into three groups (n = 12) according to the dentifrice used (Oral-B Pro-Health Whitening [OBW], Colgate Sensitive Pro-Relief [CS], Colgate Total Clean Mint 12 [CT12]). The samples were submitted to 5,000, 10,000 or 20,000 cycles of simulated toothbrushing. After each simulated period, the surface roughness of the samples was measured using a roughness tester. According to three-way analysis of variance, dentifrice (P = 0.044) and brushing time (P = 0.000) were significant. The composite resin was not significant (P = 0.381) and the interaction among the factors was not significant (P > 0.05). The mean values of the surface roughness (µm) followed by the same letter represent no statistical difference by Tukey's post-hoc test (P composite resins. The dentifrice OBW caused a higher surface roughness in both composite resins.

  13. Mechanical properties of dental resin composites by co-filling diatomite and nanosized silica particles

    International Nuclear Information System (INIS)

    Wang Hua; Zhu Meifang; Li Yaogang; Zhang Qinghong; Wang Hongzhi

    2011-01-01

    The aim of this study was to investigate the mechanical property effects of co-filling dental resin composites with porous diatomite and nanosized silica particles (OX-50). The purification of raw diatomite by acid-leaching was conducted in a hot 5 M HCl solution at 80 deg. C for 12 h. Both diatomite and nanosized SiO 2 were silanized with 3-methacryloxypropyltrimethoxysilane. The silanized inorganic particles were mixed into a dimethacrylate resin. Purified diatomite was characterized by X-ray diffraction, UV-vis diffuse reflectance spectroscopy and an N 2 adsorption-desorption isotherm. Silanized inorganic particles were characterized using Fourier transform infrared spectroscopy and a thermogravimetric analysis. The mechanical properties of the composites were tested by three-point bending, compression and Vicker's microhardness. Scanning electron microscopy was used to show the cross-section morphologies of the composites. Silanization of diatomite and nanosized silica positively reinforced interactions between the resin matrix and the inorganic particles. The mechanical properties of the resin composites gradually increased with the addition of modified diatomite (m-diatomite). The fracture surfaces of the composites exhibited large fracture steps with the addition of m-diatomite. However, when the mass fraction of m-diatomite was greater than 21 wt.% with respect to modified nanosized silica (mOX-50) and constituted 70% of the resin composite by weight, the mechanical properties of the resin composites started to decline. Thus, the porous structure of diatomite appears to be a crucial factor to improve mechanical properties of resin composites.

  14. Nonlinear DC Conduction Behavior in Graphene Nanoplatelets/Epoxy Resin Composites

    Science.gov (United States)

    Yuan, Yang; Wang, Qingguo; Qu, Zhaoming

    2018-01-01

    Graphene nanoplatelets (GNPs)/Epoxy resin (ER) with a low percolation threshold were fabricated. Then the nonlinear DC conduction behavior of GNPs/ER composites was investigated, which indicates that dispersion, exfoliation level and conductivity of GNPs in specimens are closely related to the conduction of composites. Moreover, it could be seen that the modified graphene nanoplatelets made in this paper could be successfully used for increasing the electric conductivity of the epoxy resin, and the GNPs/ER composites with nonlinear conduction behavior have a good application prospects in the field of intelligent electromagnetic protection.

  15. Radiopacity of 28 Composite Resins for Teeth Restorations.

    Science.gov (United States)

    Raitz, Ricardo; Moruzzi, Patrizia Dubinskas; Vieira, Glauco; Fenyo-Pereira, Marlene

    2016-02-01

    Radiopacity is a fundamental requisite to check marginal adaptation of restorations. Our objective was to assess the radiopacity of 28 brands of light-cured composite resins and compare their radiopacity with that of enamel, dentin, and aluminum of equivalent thickness. Composite resin disks (0.2, 0.5, and 1 mm) were radiographed by the digital method, together with an aluminum penetrometer and a human tooth equivalent tooth section. The degree of radiopacity of each image was quantified using digital image processing. Wilcoxon nonparametric test was used for comparison of the mean thickness of each material. All of the materials tested had an equal or greater radiopacity than that of aluminum of equivalent thickness. Similar results for enamel were found with the exception of Durafill, which was less radiopaque than enamel (p composite resins comply with specification #27 of the American Dental Association. The radiopacity of Amelogen Plus, Aph, Brilhiante, Charisma, Concept Advanced, Evolux X, Exthet X, Inten S, Llis, Master Fill, Natural Look, Opallis, P60, Tetric, Tph, Z100, and Z250 was significantly higher than that of enamel (p composites, it is possible to observe the boundaries between restoration and tooth structure, thus allowing clinicians to establish the presence of microleakage or restoration gap. Suitable radiopacity is an essential requisite for good-quality esthetic restorative materials. We demonstrate that only some composites have the sufficient radiopacity to observe the boundaries between restoration and tooth structure, which is the main cause of restoration failure.

  16. Color change of CAD-CAM materials and composite resin cements after thermocycling.

    Science.gov (United States)

    Gürdal, Isil; Atay, Ayse; Eichberger, Marlis; Cal, Ebru; Üsümez, Aslihan; Stawarczyk, Bogna

    2018-04-24

    The color of resin cements and computer-aided-design and computer-aided-manufacturing (CAD-CAM) restorations may change with aging. The purpose of this in vitro study was to analyze the influence of thermocycling on the color of CAD-CAM materials with underlying resin cement. Seven different CAD-CAM materials, composite resins and glass-ceramics were cut into 0.7-mm and 1.2-mm thicknesses (n=10) and cemented with a dual-polymerizing resin cement, a light-polymerizing resin cement, and a preheated composite resin (N=420). Color values were measured by using spectrophotometry. Specimens were subjected to thermocycling (5°C and 55°C; 5000 cycles). The measured color difference (ΔE) data were analyzed by using descriptive statistics. Normality of data distribution was tested by using the Kolmogorov-Smirnov test. Three-way and 1-way ANOVA followed by the Scheffé post-hoc test and unpaired 2-sample Student t test were computed to determine the significant differences among the tested parameters (α=.05). ΔE values were significantly influenced by the CAD-CAM material (η p 2 =0.85, Pcement (η P 2 =0.03, P=.003) but were not influenced by thickness (P=.179). Significant interactions were present among thickness, cement, and CAD-CAM materials (Pcement showed significantly lower ΔE values than the preheated composite resin (P=.003). Restoration materials and composite resin cement types used for cementation influence the amount of color change due to aging. Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  17. Cytotoxicity Evaluation of Two Bis-Acryl Composite Resins Using Human Gingival Fibroblasts.

    Science.gov (United States)

    Gonçalves, Fabiano Palmeira; Alves, Gutemberg; Guimarães, Vladi Oliveira; Gallito, Marco Antônio; Oliveira, Felipe; Scelza, Míriam Zaccaro

    2016-01-01

    Bis-acryl resins are used for temporary dental restorations and have shown advantages over other materials. The aim of this work was to evaluate the in vitro cytotoxicity of two bis-acryl composite resins (Protemp 4 and Luxatemp Star), obtained at 1, 7 and 40 days after mixing the resin components, using a standardized assay employing human primary cells closely related to oral tissues. Human gingival fibroblast cell cultures were exposed for 24 h to either bis-acryl composite resins, polystyrene beads (negative control) and latex (positive control) extracts obtained after incubation by the different periods, at 37 °C under 5% CO2. Cell viability was evaluated using a multiparametric procedure involving sequential assessment (using the same cells) of mitochondrial activity (XTT assay), membrane integrity (neutral red test) and total cell density (crystal violet dye exclusion test). The cells exposed to the resin extracts showed cell viability indexes exceeding 75% after 24 h. Even when cells were exposed to extracts prepared with longer conditioning times, the bis-acryl composite resins showed no significant cytotoxic effects (p>0.05), compared to the control group or in relation to the first 24 h of contact with the products. There were no differences among the results obtained for the bis-acryl composite resins evaluated 24 h, 7 days and 40 days after mixing. It may be concluded that the bis-acryl resins Protemp 4 and Luxatemp Star were cytocompatible with human gingival fibroblasts, suggesting that both materials are suitable for use in contact with human tissues.

  18. Microshear bond strength of preheated silorane- and methacrylate-based composite resins to dentin.

    Science.gov (United States)

    Demirbuga, Sezer; Ucar, Faruk Izzet; Cayabatmaz, Muhammed; Zorba, Yahya Orcun; Cantekin, Kenan; Topçuoğlu, Hüseyin Sinan; Kilinc, Halil Ibrahim

    2016-01-01

    The aim of this study was to investigate the effect of preheating on microshear bond strength (MSBS) of silorane and methacrylate-based composite resins to human dentin. The teeth were randomly divided into three main groups: (1) composite resins were heated upto 68 °C; (2) cooled to 4 °C; and (3) control [room temperature (RT)]. Each group was then randomly subdivided into four subgroups according to adhesive system used [Solobond M (Voco), All Bond SE (Bisco), Clearfil SE Bond (CSE) (Kuraray), Silorane adhesive system (SAS) (3M ESPE)]. Resin composite cylinders were formed (0.9 mm diameter × 0.7 mm length) and MSBS of each specimen was tested. The preheated groups exhibited the highest MSBS (p composite resins may be an alternative way to increase the MSBS of composites on dentin. © Wiley Periodicals, Inc.

  19. Development of new addition-type composite resins

    Science.gov (United States)

    Kray, R. J.

    1981-01-01

    The most promising of a number of new addition type polyimides and polyaromatic melamine (NCNS) resins for use in high performance composite materials. Three different cure temperature ranges were of interest: 530-560 K (500-550 F), 475-530 K (400-500 F), and 450 K (350 F). Examined were a wide variety of polyimide precursors terminated with 5 norbornene groups and addition polymerized at 560 K similar to PMR-15 and LARC-160 polyimides. In addition, a number of lower curing cinnamal end capped polyimides and a bismaleimide were investigated but were not found promising. A group of NCNS resins were investigated and some were found to be superior to current epoxy resins in moisture resistance, oxidative aging and flame and smoke properties.

  20. Application of Some Synthesized Polymeric Composite Resins for Removal of Some Metal Ions

    International Nuclear Information System (INIS)

    El-Zahhhar, A.A.; Abdel-Aziz, H.M.; Siyam, T.

    2005-01-01

    The ion-exchange and sorption characteristic of new polymeric composite resins, prepared by gamma radiation were experimentally studied. The composite resins shows high uptake for Co(II) and Eu(III) ions in aqueous solutions in wide range of ph. The selectivity of the resins to Co (II) or Eu (III) species in the presence of some competing ions and complexing agents (as Na + , Fe 3+ , EDTA Na 2 , etc.) was compared. Various factors that could affect the sorption behaviors of metal ions (Co (II) and Eu (III)) on the prepared polymeric composite resins were studied such as ionic strength, Contact time, volume mass ratio

  1. A comparative study to determine strength of autopolymerizing acrylic resin and autopolymerizing composite resin influenced by temperature during polymerization: An In Vitro study

    Directory of Open Access Journals (Sweden)

    Anuj Chhabra

    2017-01-01

    Full Text Available Aim: Temporary coverage of a prepared tooth is an important step during various stages of the fixed dental prosthesis. Provisional restorations should satisfy proper mechanical requirements to resist functional and nonfunctional loads. A few studies are carried out regarding the comparison of the effect of curing environment, air and water, on mechanical properties of autopolymerizing acrylic and composite resin. Hence, the aim of this study was to compare the transverse strength of autopolymerizing acrylic resin and autopolymerizing composite resin as influenced by the temperature of air and water during polymerization. Materials and Methods: Samples of autopolymerizing acrylic resin and composite resin were prepared by mixing as per manufacturer's instructions and were placed in a preformed stainless steel mold. The mold containing the material was placed under different controlled conditions of water temperature and air at room temperature. Polymerized samples were then tested for transverse strength using an Instron universal testing machine. Results: Alteration of curing condition during polymerization revealed a significant effect on the transverse strength. The transverse strength of acrylic resin specimens cured at 60°C and composite resin specimens cured at 80°C was highest. Polymerizing the resin in cold water at 10°C reduced the mechanical strength. Conclusions: Polymerization of the resin in hot water greatly increased its mechanical properties. The method of placing resin restoration in hot water during polymerization may be useful for improving the mechanical requirements and obtaining long-lasting performance.

  2. [Bonding of visible light cured composite resins to glass ionomer and Cermet cements].

    Science.gov (United States)

    Kakaboura, A; Vougiouklakis, G

    1990-04-01

    The "sandwich" technique involves combination of composite resins to etched glassionomer cements, is used today in restorative dentistry. The purpose of this study is to evaluate the bond strength between several composite resins and glass ionomer or cerment cements. Cylindrical specimens of the cements Ketac-Silver, Ionobond and GC-Lining Ce-ment were inserted in a mold and their flat free surfaces were etched for 30". Cylindrical plastic tubes were set upon each one of these surfaces and filled with the Composite resins Durafill, Brilliant Lux, Estilux posterior, Estilux posterior CVS and Herculite XR. Half of the specimens transferred in tap water for 24 hours and the others after thermocycling in the first month, kept for 4 months. Shear bond strengths were determined in Monsanto Testing Machine and some fractured surfaces were examined under SEM. The results of this investigation indicate that this technique produces bond strengths between composite resins and glassioners and the combination type of resin and type of cement, affects the values of the strength. Glass cermeet--small particle resin provides the most effective strength and glass ionomer--microfill resins the least. Storage time and thermocycling don't significantly effect the bond strength. SEM examination showed that all fracture failures were obtained in the cement while the opposite resin surfaces were covered with particles of the cements.

  3. Effect of bench time polymerization on depth of cure of dental composite resin

    Science.gov (United States)

    Harahap, K.; Yudhit, A.; Sari, F.

    2017-07-01

    The aim of this research was to investigate the effect of bench time before light cured polymerization on the depth of cure of dental composite resin. Nanofiller composite resin (Filtek Z350 XT,3M, ESPE,China) was used in this study. Sixty samples of nanofiller composite resin were made and divided into control and test groups with bench time for 0, 15, 30, 45, and 60 min. For the test group, composite resins were stored in refrigerator with 4°C temperatures. Meanwhile, for the control groups, the composite resin was stored at room temperature. The samples were prepared using metal mould with size diameter of 6 mm and 4 mm in thickness. Samples were cured for 20 s by using visible blue light curing unit. Part of samples that unpolymerized were removed by using a plastic spatula. The remaining parts of samples were measured by digital caliper and noted as depth of cure (mm). Data were analyzed to one-way ANOVA and LSD tests (p≤0.05). Results showed there was no significance differences between test groups (p=0.5). A 60 minutes bench time group showed the highest depth of cure value among test group, and it was almost similar with control group value. It can be concluded that longer bench time can increase the depth of cure of composite resin.

  4. Equivalent Young's modulus of composite resin for simulation of stress during dental restoration.

    Science.gov (United States)

    Park, Jung-Hoon; Choi, Nak-Sam

    2017-02-01

    For shrinkage stress simulation in dental restoration, the elastic properties of composite resins should be acquired beforehand. This study proposes a formula to measure the equivalent Young's modulus of a composite resin through a calculation scheme of the shrinkage stress in dental restoration. Two types of composite resins remarkably different in the polymerization shrinkage strain were used for experimental verification: the methacrylate-type (Clearfil AP-X) and the silorane-type (Filtek P90). The linear shrinkage strains of the composite resins were gained through the bonded disk method. A formula to calculate the equivalent Young's moduli of composite resin was derived on the basis of the restored ring substrate. Equivalent Young's moduli were measured for the two types of composite resins through the formula. Those values were applied as input to a finite element analysis (FEA) for validation of the calculated shrinkage stress. Both of the measured moduli through the formula were appropriate for stress simulation of dental restoration in that the shrinkage stresses calculated by the FEA were in good agreement within 3.5% with the experimental values. The concept of equivalent Young's modulus so measured could be applied for stress simulation of 2D and 3D dental restoration. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Nanoindentation creep versus bulk compressive creep of dental resin-composites.

    Science.gov (United States)

    El-Safty, S; Silikas, N; Akhtar, R; Watts, D C

    2012-11-01

    To evaluate nanoindentation as an experimental tool for characterizing the viscoelastic time-dependent creep of resin-composites and to compare the resulting parameters with those obtained by bulk compressive creep. Ten dental resin-composites: five conventional, three bulk-fill and two flowable were investigated using both nanoindentation creep and bulk compressive creep methods. For nano creep, disc specimens (15mm×2mm) were prepared from each material by first injecting the resin-composite paste into metallic molds. Specimens were irradiated from top and bottom surfaces in multiple overlapping points to ensure optimal polymerization using a visible light curing unit with output irradiance of 650mW/cm(2). Specimens then were mounted in 3cm diameter phenolic ring forms and embedded in a self-curing polystyrene resin. Following grinding and polishing, specimens were stored in distilled water at 37°C for 24h. Using an Agilent Technologies XP nanoindenter equipped with a Berkovich diamond tip (100nm radius), the nano creep was measured at a maximum load of 10mN and the creep recovery was determined when each specimen was unloaded to 1mN. For bulk compressive creep, stainless steel split molds (4mm×6mm) were used to prepare cylindrical specimens which were thoroughly irradiated at 650mW/cm(2) from multiple directions and stored in distilled water at 37°C for 24h. Specimens were loaded (20MPa) for 2h and unloaded for 2h. One-way ANOVA, Levene's test for homogeneity of variance and the Bonferroni post hoc test (all at p≤0.05), plus regression plots, were used for statistical analysis. Dependent on the type of resin-composite material and the loading/unloading parameters, nanoindentation creep ranged from 29.58nm to 90.99nm and permanent set ranged from 8.96nm to 30.65nm. Bulk compressive creep ranged from 0.47% to 1.24% and permanent set ranged from 0.09% to 0.38%. There was a significant (p=0.001) strong positive non-linear correlation (r(2)=0.97) between bulk

  6. Evaluating resin-enamel bonds by microshear and microtensile bond strength tests: effects of composite resin

    Science.gov (United States)

    de ANDRADE, Andrea Mello; MOURA, Sandra Kiss; REIS, Alessandra; LOGUERCIO, Alessandro Dourado; GARCIA, Eugenio Jose; GRANDE, Rosa Helena Miranda

    2010-01-01

    Objectives The aims of this study were to evaluate the effect of resin composite (Filtek Z250 and Filtek Flow Z350) and adhesive system [(Solobond Plus, Futurabond NR (VOCO) and Adper Single Bond (3M ESPE)] on the microtensile (µTBS) and microshear bond strength (µSBS) tests on enamel, and to correlate the bond strength means between them. Material and methods Thirty-six extracted human molars were sectioned to obtain two tooth halves: one for µTBS and the other one for µSBS. Adhesive systems and resin composites were applied to the enamel ground surfaces and light-cured. After storage (37ºC/24 h) specimens were stressed (0.5 mm/ min). Fracture modes were analyzed under scanning electron microscopy. The data were analyzed using two-way ANOVA and Tukey's test (α=0.05). Results The correlation between tests was estimated with Pearson's product-moment correlation statistics (α =0.05). For both tests only the main factor resin composite was statistically significant (padhesives. Both microbond tests seem to be positive and linearly correlated and can therefore lead to similar conclusions. PMID:21308290

  7. Mechanical properties of dental resin composites by co-filling diatomite and nanosized silica particles

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hua; Zhu Meifang [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); Li Yaogang [Engineering Research Center of Advanced Glasses Manufacturing Technology, MOE, Donghua University, Shanghai 201620 (China); Zhang Qinghong, E-mail: zhangqh@dhu.edu.cn [Engineering Research Center of Advanced Glasses Manufacturing Technology, MOE, Donghua University, Shanghai 201620 (China); Wang Hongzhi, E-mail: wanghz@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China)

    2011-04-08

    The aim of this study was to investigate the mechanical property effects of co-filling dental resin composites with porous diatomite and nanosized silica particles (OX-50). The purification of raw diatomite by acid-leaching was conducted in a hot 5 M HCl solution at 80 deg. C for 12 h. Both diatomite and nanosized SiO{sub 2} were silanized with 3-methacryloxypropyltrimethoxysilane. The silanized inorganic particles were mixed into a dimethacrylate resin. Purified diatomite was characterized by X-ray diffraction, UV-vis diffuse reflectance spectroscopy and an N{sub 2} adsorption-desorption isotherm. Silanized inorganic particles were characterized using Fourier transform infrared spectroscopy and a thermogravimetric analysis. The mechanical properties of the composites were tested by three-point bending, compression and Vicker's microhardness. Scanning electron microscopy was used to show the cross-section morphologies of the composites. Silanization of diatomite and nanosized silica positively reinforced interactions between the resin matrix and the inorganic particles. The mechanical properties of the resin composites gradually increased with the addition of modified diatomite (m-diatomite). The fracture surfaces of the composites exhibited large fracture steps with the addition of m-diatomite. However, when the mass fraction of m-diatomite was greater than 21 wt.% with respect to modified nanosized silica (mOX-50) and constituted 70% of the resin composite by weight, the mechanical properties of the resin composites started to decline. Thus, the porous structure of diatomite appears to be a crucial factor to improve mechanical properties of resin composites.

  8. Initial polishing time affects gloss retention in resin composites.

    Science.gov (United States)

    Waheeb, Nehal; Silikas, Nick; Watts, David

    2012-10-01

    To determine the effect of finishing and polishing time on the surface gloss of various resin-composites before and after simulated toothbrushing. Eight representative resin-composites (Ceram X mono, Ceram X duo, Tetric EvoCeram, Venus Diamond, EsteliteSigma Quick, Esthet.X HD, Filtek Supreme XT and Spectrum TPH) were used to prepare 80 disc-shaped (12 mm x 2 mm) specimens. The two step system Venus Supra was used for polishing the specimens for 3 minutes (Group A) and 10 minutes (Group B). All specimens were subjected to 16,000 cycles of simulated toothbrushing. The surface gloss was measured after polishing and after brushing using the gloss meter. Results were evaluated using one way ANOVA, two ways ANOVA and Dennett's post hoc test (P = 0.05). Group B (10-minute polishing) resulted in higher gloss values (GV) for all specimens compared to Group A (3 minutes). Also Group B showed better gloss retention compared to Group A after simulated toothbrushing. In each group, there was a significant difference between the polished composite resins (P gloss after the simulated toothbrushing.

  9. Repair Strength in Simulated Restorations of Methacrylate- or Silorane-Based Composite Resins.

    Science.gov (United States)

    Consani, Rafael Leonardo Xediek; Marinho, Tatiane; Bacchi, Atais; Caldas, Ricardo Armini; Feitosa, Victor Pinheiro; Pfeifer, Carmem Silvia

    2016-01-01

    The study verified the bond strength in simulated dental restorations of silorane- or methacrylate-based composites repaired with methacrylate-based composite. Methacrylate- (P60) or silorane-based (P90) composites were used associated with adhesive (Adper Single Bond 2). Twenty-four hemi-hourglass-shaped samples were repaired with each composite (n=12). Samples were divided according to groups: G1= P60 + Adper Single Bond 2+ P60; G2= P60 + Adper Single Bond 2 + P60 + thermocycling; G3= P90 + Adper Single Bond 2 + P60; and G4= P90 + Adper Single Bond 2 + P60 + thermocycling. G1 and G3 were submitted to tensile test 24 h after repair procedure, and G2 and G4 after submitted to 5,000 thermocycles at 5 and 55 ?#61616;C for 30 s in each bath. Tensile bond strength test was accomplished in an universal testing machine at crosshead speed of 0.5 mm/min. Data (MPa) were analyzed by two-way ANOVA and Tukey's test (5%). Sample failure pattern (adhesive, cohesive in resin or mixed) was evaluated by stereomicroscope at 30?#61655; and images were obtained in SEM. Bond strength values of methacrylate-based composite samples repaired with methacrylate-based composite (G1 and G2) were greater than for silorane-based samples (G3 and G4). Thermocycling decreased the bond strength values for both composites. All groups showed predominance of adhesive failures and no cohesive failure in composite resin was observed. In conclusion, higher bond strength values were observed in methacrylate-based resin samples and greater percentage of adhesive failures in silorane-based resin samples, both composites repaired with methacrylate-based resin.

  10. Effects of 35% Carbamide Peroxide Gel on Surface Roughness and Hardness of Composite Resins

    Directory of Open Access Journals (Sweden)

    F. Sharafeddin

    2010-03-01

    Full Text Available Objective: Bleaching agents may not be safe for dental materials. The purpose of this invitro study was to evaluate the effects of Opalescent Quick "in-office bleaching gel" containing 35% carbamide peroxide on the surface roughness and hardness of microfilled(Heliomolar and hybride (Spectrum TPH composite resins.Materials and Methods: Twenty specimens of Spectrum TPH composite resins and twenty Heliomolar composite resins were fabricated using a metallic ring (6.5 mm diameter and 2.5 mm thickness and light cured, then their surfaces were polished. Specimens of each composite resin were divided into two equal groups. Ten specimens of each type of composite were stored in water at 37°C as the control groups and 35% carbamide peroxide gel (Opalescence Quick as the other group for 30 minutes a week for 3 weeks. Then the specimens were subject to roughness and hardness tests.Results: This study revealed that using 35% carbamide peroxide bleaching gels had no significant effect on the surface roughness of Spectrum TPH "hybrid" and Heliomolar "microfilled" composite resins. The surface hardness of Spectrum TPH composite treated with the subject gel significantly increased compared to heliomolar, which had no significant change after treatment with this bleaching gel.Conclusion: If tooth color matching of the composite had been satisfactory after office bleaching with 35% carbamide peroxide gel, this material would have been acceptable because it has no adverse effect on Heliomolar and Spectrum TPH composite resins.

  11. The effectiveness of different polymerization protocols for class II composite resin restorations.

    NARCIS (Netherlands)

    Jong, L.C.G. de; Opdam, N.J.M.; Bronkhorst, E.M.; Roeters, F.J.M.; Wolke, J.G.C.; Geitenbeek, B.

    2007-01-01

    OBJECTIVES: To investigate the effect of reduced light exposure times on Vickers hardness (VH) of class II composite resin restorations. METHODS: Class II restorations were made in vitro in three 2mm thick increments in a human molar. Two composite resins (Clearfil AP-X; Esthet-X) were polymerized

  12. Synthesis of wrinkled mesoporous silica and its reinforcing effect for dental resin composites.

    Science.gov (United States)

    Wang, Ruili; Habib, Eric; Zhu, X X

    2017-10-01

    The aim of this work is to explore the reinforcing effect of wrinkled mesoporous silica (WMS), which should allow micromechanical resin matrix/filler interlocking in dental resin composites, and to investigate the effect of silica morphology, loading, and compositions on their mechanical properties. WMS (average diameter of 496nm) was prepared through the self-assembly method and characterized by the use of the electron microscopy, dynamic light scattering, and the N 2 adsorption-desorption measurements. The mechanical properties of resin composites containing silanized WMS and nonporous smaller silica were evaluated with a universal mechanical testing machine. Field-emission scanning electron microscopy was used to study the fracture morphology of dental composites. Resin composites including silanized silica particles (average diameter of 507nm) served as the control group. Higher filler loading of silanized WMS substantially improved the mechanical properties of the neat resin matrix, over the composites loaded with regular silanized silica particles similar in size. The impregnation of smaller secondary silica particles with diameters of 90 and 190nm, denoted respectively as Si90 and Si190, increased the filler loading of the bimodal WMS filler (WMS-Si90 or WMS-Si190) to 60wt%, and the corresponding composites exhibited better mechanical properties than the control fillers made with regular silica particles. Among all composites, the optimal WMS-Si190- filled composite (mass ratio WMS:Si190=10:90, total filler loading 60wt%) exhibited the best mechanical performance including flexural strength, flexural modulus, compressive strength and Vickers microhardness. The incorporation of WMS and its mixed bimodal fillers with smaller silica particles led to the design and formulation of dental resin composites with superior mechanical properties. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  13. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    International Nuclear Information System (INIS)

    Yudovin-Farber, Ira; Beyth, Nurit; Weiss, Ervin I.; Domb, Abraham J.

    2010-01-01

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  14. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yudovin-Farber, Ira [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel); Beyth, Nurit; Weiss, Ervin I. [Hebrew University of Jerusalem, Department of Prosthodontics, Faculty of Dentistry (Israel); Domb, Abraham J., E-mail: avid@ekmd.huji.ac.i [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel)

    2010-02-15

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  15. SORPTION AND SOLUBILITY OF LOW-SHRINKAGE RESIN-BASED DENTAL COMPOSITES

    Directory of Open Access Journals (Sweden)

    Sevda Yantcheva

    2016-04-01

    Full Text Available Background: Resin-based composites are well-established restorative materials. However, these materials may absorb significant amounts of water when exposed to aqueous environments. Sorption and solubility are affecting composite restorations by two different mechanisms; the first is the up taking of water producing an increased weight and the second is the dissolution of materials in water, leading to a weight reduction of the final conditioned samples. Objective: To measure the water sorption and solubility of different low-shrinkage resin-based composites. Six materials were selected: Filtek P60, Filtek Ultimate, SonicFill, Filtek Silorane, Kalore and Venus Diamond. Materials and methods: Five disc specimens were prepared of each material and polymerized with diode light-curing unit. Water sorption and solubility of the different materials were were calculated by means of weighting the samples before and after water immersion and desiccation. Data were statistically analyzed using Shapiro-Wilk One Way Analysis of Variance followed by the Holm-Sidak comparison test . Results: There were significant differences (p<=0.001 between materials regarding sorption and solubility. Regarding sorption F. Silorane showed lowest values, followed by SonicFill, without significant difference between them. Statistical significant differences exist between F. Silorane and F.P60, F. Ultimate, Kalore. Significant differences exist between SonicFill and F. Ultimate. F.Silorane (-0.018 and Kalore (-0.010 showed lowest values of solubility but there were marginal difference among all composites investigated. Conclusions: 1.The material with lowest values of sorption and solubility was F.Silorane. 2. The attained sorption and solubility values for composites are influenced by the differences in resin matrix composition and filler contend. 3. Modifications of dimethacrylate matrix did not minimize significantly sorption and solubility of composites. 4. Besides water

  16. Translucency, opalescence and light transmission characteristics of light-cured resin composites.

    Science.gov (United States)

    Arimoto, Ayako; Nakajima, Masatoshi; Hosaka, Keiichi; Nishimura, Kozo; Ikeda, Masaomi; Foxton, Richard M; Tagami, Junji

    2010-11-01

    To evaluate the translucency, opalescence and light transmission characteristics of resin composites with different thicknesses. Disks of three resin composites (Estelite∑, Beautifil II, Clearfil Majesty) of A2 shade were prepared in diameter of 10mm with various thicknesses (0.5mm, 1.0mm and 2.0mm). Color was measured according to CIELAB color scale on a reflection spectrophotometer and a color haze meter, and translucency parameter (TP) and opalescence parameter (OP) were calculated. Using the distribution graphs of transmitted light intensity on a goniophotometer, diffusion factor (DF) as an indicator for a diffuse transmission property and peak gain (G0) for a straight-line transmission property were calculated. The TP and G0 values significantly decreased in the order: 0.5mm>1.0mm>2.0mm thickness (popalescence (OP) of resin composites had a significant correlation with a diffuse transmission property (DF). When more than 1.0mm thickness of resin composites, translucency and opalescence were influenced by the thickness, in which translucency significantly decreased and opalescence significantly increased. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  17. Bioinspired Catecholic Primers for Rigid and Ductile Dental Resin Composites.

    Science.gov (United States)

    Shin, Eeseul; Ju, Sung Won; An, Larry; Ahn, Eungjin; Ahn, Jin-Soo; Kim, Byeong-Su; Ahn, B Kollbe

    2018-01-17

    In the construction of dental restorative polymer composite materials, surface priming on mineral fillers is essential to improve the mechanical performance of the composites. Here we present bioinspired catechol-functionalized primers for a tougher dental resin composite containing glass fillers. The catecholic primers with different polymerizable end groups were designed and then coated on glass surfaces using a simple drop-casting or dip-coating process. The surface binding ability and possible cross-linking (coupling or chemical bridging between the glass substrate and the dental resin) of the catecholic bifunctional primers were evaluated using atomic force microscopy, contact angle measurements, and the knife shear bonding test and compared to a state-of-the-art silane-based coupling agent. Various mechanical tests including shrinkage and compression tests of the dental resin composites were also conducted. Compression tests of the composites containing the catecholic primed fillers exhibited enhanced mechanical properties, owing to the bidentate hydrogen bonding of catechol moieties to the oxide mineral surface. Furthermore, the superior biocompatibility of the primed surface was confirmed via cell attachment assay, thus providing applicability of catecholic primers for practical dental and biomedical applications.

  18. Assessment of polymerization contraction stress of three composite resins

    NARCIS (Netherlands)

    Cadenaro, M.; Biasotto, M.; Scuor, N.; Breschi, L.; Davidson, C.L.; Di Lenarda, R.

    2008-01-01

    Objectives: The purpose of this study was to measure the development of contraction stress of three composite resin restorative materials during photo-polymerization: a micro-hybrid composite (Filtek Z250, 3M ESPE, St. Paul, MN, USA); a nano-filled composite (Filtek Supreme, 3M ESPE, St. Paul, MN,

  19. Effect of Various Surface Treatment on Repair Strength of Composite Resin

    Directory of Open Access Journals (Sweden)

    Y. Alizade

    2004-12-01

    Full Text Available Statement of Problem: In some clinical situations, repair of composite restorations is treatment of choice. Improving the bond strength between one new and old composite usually requires increased surface roughness to promote mechanical interlocking sincechemical bonding might not be adequate. Similarly, the treatment of a laboratory fabricated resin composite restoration involves the same procedures, and there is a need to create the strongest possible bond of a resin cement to a previously polymerized composite.Purpose: The aim of this study was to evaluate the effect of various surface treatments on the shear bond strength of repaired to aged composite resin.Materials and Methods: Eighty four cylindrical specimens of a composite resin were fabricated and stored in distilled water for 100 days prior to surface treatment. Surface treatment of old composite was done in 6 groups as follow:1- Air abrasion with CoJet sand particles with micoretcher + silane + dentin bonding agent2- Air abrasion with 50μm Al2O3 particles+ phosphoric acid+ silane+ dentin bonding agent3- Air abrasion with 50μm Al2O3 particles + phosphoric acid + dentin bonding agent4- Diamond bur + phosphoric acid + silane + dentin bonding agent5- Diamond bur + phosphoric acid + dentin bonding agent6- Diamond bur + phosphoric acid + composite activator + dentin bonding agentThen fresh composite resin was bonded to treated surfaces. Twelve specimens were also fabricated as control group with the same diameter but with the height twice as much as other specimens. All of the specimens were thermocycled prior to testing for shear bondstrength. The bond strength data were analyzed statistically using one way ANOVA test, t test and Duncan's grouping test.Results: One-way ANOVA indicated no significant difference between 7 groups (P=0.059. One-way ANOVA indicated significant difference between the three diamond bur groups (P=0.036. Silane had a significant effect on the repair bond

  20. Shear bond strength evaluation of resin composite to resin-modified glass-ionomer cement using three different resin adhesives vs. glass-ionomer based adhesive

    Directory of Open Access Journals (Sweden)

    Mostafa Sadeghi

    2015-12-01

    Full Text Available Background: The clinical success of sandwich technique depends on the strength of resin-modified glass ionomer cement (RMGIC bonding to both dentin and resin composite. Therefore, the shear bond strength (SBS of resin composite bonded to RMGIC utilizing different resin adhesives versus a GIC-based adhesive was compared. Materials and methods: In this in vitro study, 84 holes (5×2 mm were prepared in acrylic blocks, randomly divided into seven groups (n=12 and filled with RMGIC (Light-Cured Universal Restorative, GC. In the Group I; no adhesive was applied on the RMGIC. In the Group II, non-etched and Group III was etched with phosphoric acid. In groups II and III, after rinsing, etch-and-rinse adhesive (OptiBond Solo Plus; in the Group IV; a two-step self-etch adhesive (OptiBond XTR and in Group V; a one-step self-etch (OptiBond All-in-One were applied on the cement surfaces. Group VI; a GIC-based adhesive (Fuji Bond LC was painted over the cement surface and cured. Group VII; the GIC-based adhesive was brushed over RMGIC followed by the placement of resin composite and co-cured. Afterward; resin composite (Point 4 cylinders were placed on the treated cement surfaces. The specimens were placed in 100% humidity at 37 ± 1°C and thermo cycled. The shear bond test was performed at a cross-head speed of 1 mm/min and calculated in MPa; the specimens were examined to determine mode of failure. The results were analyzed using one-way ANOVA and Tukey test. Results: The maximum (24.62±3.70 MPa and minimum (18.15±3.38 MPa SBS mean values were recorded for OptiBond XTR adhesive and the control group, respectively. The pairwise comparisons showed no significant differences between the groups that bonded with different adhesives. The adhesive failure was the most common failure mode observed. Conclusion: This study suggests that GIC-based adhesive could be applied over RMGIC as co-cure technique for sandwich restorations in lieu of employing the resin

  1. Push-Out Bond Strength of Restorations with Bulk-Fill, Flow, and Conventional Resin Composites

    Directory of Open Access Journals (Sweden)

    Rodrigo Vieira Caixeta

    2015-01-01

    Full Text Available The aim of this study was to evaluate the bond strengths of composite restorations made with different filler amounts and resin composites that were photoactivated using a light-emitting diode (LED. Thirty bovine incisors were selected, and a conical cavity was prepared in the facial surface of each tooth. All preparations were etched with Scotchbond Etching Gel, the Adper Scotchbond Multipurpose Plus adhesive system was applied followed by photoactivation, and the cavities were filled with a single increment of Filtek Z350 XT, Filtek Z350 XT Flow, or bulk-fill X-tra fil resin composite (n = 10 followed by photoactivation. A push-out test to determine bond strength was conducted using a universal testing machine. Data (MPa were submitted to Student’s t-test at a 5% significance level. After the test, the fractured specimens were examined using an optical microscope under magnification (10x. Although all three composites demonstrated a high prevalence of adhesive failures, the bond strength values of the different resin composites photoactivated by LED showed that the X-tra fil resin composite had a lower bond strength than the Filtek Z350 XT and Filtek Z350 XT Flow resin composites.

  2. Advanced resin systems and 3D textile preforms for low cost composite structures

    Science.gov (United States)

    Shukla, J. G.; Bayha, T. D.

    1993-01-01

    Advanced resin systems and 3D textile preforms are being evaluated at Lockheed Aeronautical Systems Company (LASC) under NASA's Advanced Composites Technology (ACT) Program. This work is aimed towards the development of low-cost, damage-tolerant composite fuselage structures. Resin systems for resin transfer molding and powder epoxy towpreg materials are being evaluated for processability, performance and cost. Three developmental epoxy resin systems for resin transfer molding (RTM) and three resin systems for powder towpregging are being investigated. Various 3D textile preform architectures using advanced weaving and braiding processes are also being evaluated. Trials are being conducted with powdered towpreg, in 2D weaving and 3D braiding processes for their textile processability and their potential for fabrication in 'net shape' fuselage structures. The progress in advanced resin screening and textile preform development is reviewed here.

  3. A study on the compatibility between one-bottle dentin adhesives and composite resins using micro-shear bond strength.

    Science.gov (United States)

    Song, Minju; Shin, Yooseok; Park, Jeong-Won; Roh, Byoung-Duck

    2015-02-01

    This study was performed to determine whether the combined use of one-bottle self-etch adhesives and composite resins from same manufacturers have better bond strengths than combinations of adhesive and resins from different manufacturers. 25 experimental micro-shear bond test groups were made from combinations of five dentin adhesives and five composite resins with extracted human molars stored in saline for 24 hr. Testing was performed using the wire-loop method and a universal testing machine. Bond strength data was statistically analyzed using two way analysis of variance (ANOVA) and Tukey's post hoc test. Two way ANOVA revealed significant differences for the factors of dentin adhesives and composite resins, and significant interaction effect (p composite resin (p composite resin than other manufacturer's composite resin. Not all combinations of adhesive and composite resin by same manufacturers failed to show significantly higher bond strengths than mixed manufacturer combinations.

  4. Repair bond strength of nanohybrid composite resins with a universal adhesive.

    Science.gov (United States)

    Altinci, Pinar; Mutluay, Murat; Tezvergil-Mutluay, Arzu

    2018-01-01

    Objective: To investigate the repair bond strength of fresh and aged nanohybrid and hybrid composite resins using a universal adhesive (UA). Materials and methods: Fresh and aged substrates were prepared using two nanohybrid (Venus Pearl, Heraus Kulzer; Filtek Supreme XTE, 3 M ESPE) and one hybrid (Z100, 3 M ESPE) composite resin, and randomly assigned to different surface treatments: (1) no treatment (control), (2) surface roughening with 320-grit (SR), (3) SR + UA (iBOND, Heraus Kulzer), (4) SR + Silane (Signum, Ceramic Bond I, Heraeus Kulzer) + UA, (5) SR + Sandblasting (CoJet, 3 M ESPE) + Silane + UA. After surface treatment, fresh composite resin was added to the substrates at 2 mm layer increments to a height of 5 mm, and light cured. Restored specimens were water-stored for 24 h and sectioned to obtain 1.0 × 1.0 mm beams ( n  = 12), and were either water-stored for 24 h at 37 °C, or water-stored for 24 h, and then thermocycled for 6000 cycles before microtensile bond strength (µTBS) testing. Data were analyzed with ANOVA and Tukey's HSD tests ( p  = .05). Results: Combined treatment of SR, sandblasting, silane and UA provided repair bond strength values comparable to the cohesive strength of each tested resin material ( p  composite resins upto 65% ( p  composite repair. Sandblasting and silane application slightly increases the repair strength for all substrate types.

  5. Influence of a peracetic acid-based immersion on indirect composite resin.

    Science.gov (United States)

    Samuel, Susana Maria Werner; Fracaro, Gisele Baggio; Collares, Fabrício Mezzomo; Leitune, Vicente Castelo Branco; Campregher, Ulisses Bastos

    2011-06-01

    The aim of this study was to evaluate the influence of immersion in a 0.2% peracetic acid-based disinfectant on the three-point flexural strength, water sorption and water solubility of an indirect composite resin. Specimens were produced according to ISO 4049:2000 specifications and were divided in two groups: Control group, with no disinfection and Disinfected group, with three 10 min immersions in the peracetic acid intercalated with 10 min immersions in sterile distilled water. All evaluations were conducted in compliance with ISO specifications. Three-point flexural strength, water sorption and solubility of indirect composite resin before and after immersion showed no statistical significant differences (p > 0.05) and met ISO standard requirements. Immersion in peracetic acid solution showed no influence in indirect composite resin tested properties.

  6. Effect of Different Liners on Fracture Resistance of Premolars Restored with Conventional and Short Fiber-Reinforced Composite Resins.

    Science.gov (United States)

    Shafiei, Fereshteh; Doozandeh, Maryam; Ghaffaripour, Dordaneh

    2018-01-11

    To see whether applying four different liners under short fiber-reinforced composite (SFRC), everX Posterior, compared to conventional composite resin, Z250, affected their strengthening property in premolar MOD cavities. Mesio-occluso-distal (MOD) cavities were prepared in 120 sound maxillary premolars divided into 10 groups (n = 12) in terms of two composite resin types and 4 liners or no liner. For each composite resin, in 5 groups no liner, resin-modified glass ionomer (RMGI), conventional flowable composite (COFL), self-adhesive flowable composite resin (SAFL), and self-adhesive resin cement (SARC) were applied prior to restoring incrementally. After water storage and thermocycling, static fracture resistance was tested. Data (in Newtons) were analyzed using two-way ANOVA (α = 0.05). Fracture resistance was significantly affected by composite resin type (p = 0.02), but not by the liner (p > 0.05). The interaction of the two factors was not statistically significant (p > 0.05). SFRC exhibited higher fracture strength (1470 ± 200 N) compared to conventional composite resin (1350 ± 290), irrespective of the application of liners. Application of SARC and SAFL liners led to a higher number of restorable fractures for both composite resins. The four liners can be used without interfering with the higher efficacy of SFRC, compared to conventional composite resins, to improve the fracture strength of premolar MOD cavities. © 2018 by the American College of Prosthodontists.

  7. Synthesis of iodine-containing cyclophosphazenes for using as radiopacifiers in dental composite resin

    International Nuclear Information System (INIS)

    Zhao, Yuchen; Lan, Jinle; Wang, Xiaoyan; Deng, Xuliang; Cai, Qing; Yang, Xiaoping

    2014-01-01

    In this study, a strategy of using iodine-containing cyclophosphazenes as radiopacifiers for dental composite resin was evaluated. It was hypothesized that cyclophosphazenes bearing both iodine and acrylate group swere able to endow composite resins radiopacity without compromising mechanical properties. The cyclophosphazene compounds were synthesized by subsequently nucleophilic substitution of hexachlorocyclotriphosphazene with hydroxyethyl methacrylate (HEMA) and 4-iodoaniline. Cyclotriphosphazenes containing two different molar ratios of HEMA to 4-iodoaniline (1:5 and 2:4) were obtained, and were identified with 1 H NMR, FT-IR, UV and mass spectroscopy. The iodine-containing cyclophosphazenes were able to dissolve well in bisphenol A glycidyl methacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) resin, and were added at two contents (10 or 15%wt. of the resin). The resins were photo-cured and post-thermal treated before characterizations. The resulting composite resins demonstrated the ability of blocking X-ray. And the addition of HEMA-co-iodoaniline substituted cyclotriphosphazenes caused minor adverse effect on the mechanical properties of the resins because the cyclotriphosphazenes could mix well and react with the resins. The presence of rigid phosphazene rings between resin backbones displayed an effective function of decreasing polymerization shrinkage. In summary, soluble and reactive iodine-containing cyclotriphosphazenes demonstrated advantages over traditional heavy metals or metal oxides in being used as additives for producing radiopaque dental resins. - Highlights: • Iodine-containing cyclotriphosphazenes were prepared via nucleophilic substitution. • The cyclotriphosphazenes endowed Bis-GMA/TEGDMA resins radiopacity. • The cyclotriphosphazenes caused a minor adverse effect on mechanical properties

  8. Effectiveness of bleaching agent on composite resin discoloration

    Directory of Open Access Journals (Sweden)

    Galih Sampoerno

    2012-03-01

    Full Text Available Background: The discoloration of teeth, especially anterior teeth, is one of aesthetic problems. The use of tooth bleaching agents for discolored natural teeth is becoming increasingly popular. Many dentists, however, get many problems when they conduct bleaching process since there is much composite filling on patient’s anterior teeth. Although many research have focused on the discoloration of composite resin after bleaching process, the problem still becomes debatable. Purpose: The purpose of this study was to investigate the difference of the discoloration between hybrid composite and nano composite before and after the application of tooth bleaching agent, 38% hydrogen peroxide. Methods: Eighteen disk-shaped specimens (5 mm of each of two composite resins, hybrid and nano filler, were prepared. The each group was treated 3 times and the specimens were divided into two groups consisted of 9 specimens for each, and then immersed in black tea solutions for 72 hours. Next, after having staining and bleaching processes, the color of the specimens was measured with a optic spectrophotometer by using photo with type BPY-47 and digital microvolt. The differences of the light intensity among three measurements were then calculated. Afterwards, GLM MANOVA Repeated Measure and parametric analysis (Independent t-test and Paired t-test were then used to analyze the data. Results: After staining process, it is then known that the nano composite had more discoloration and more affected by the black tea solution than the hybrid one. Conclusion: After bleaching, the discoloration was finally removed completely from both hybride and nano filler composite resins and became brighter from the baseline color.Latar belakang: Salah satu problem estetik adalah adanya perubahan warna pada gigi anterior. Peningkatan pemakaian bahan bleaching semakin popular. Banyak dokter gigi mempunyai problem ketika mereka akan melakukan proses bleaching dan ditemukan banyak

  9. Effects of 35% Carbamide Peroxide Gel on Surface Roughness and Hardness of Composite Resins

    OpenAIRE

    Sharafeddin, F.; Jamalipour, GR.

    2010-01-01

    Objective: Bleaching agents may not be safe for dental materials. The purpose of this in-vitro study was to evaluate the effects of Opalescent Quick ?in-office bleaching gel? containing 35% carbamide peroxide on the surface roughness and hardness of microfilled (Heliomolar) and hybride (Spectrum TPH) composite resins. Materials and Methods: Twenty specimens of Spectrum TPH composite resins and twenty Heliomolar composite resins were fabricated using a metallic ring (6.5 mm diameter and 2.5 mm...

  10. PETI-298 Prepared by Microwave Synthesis: Neat Resin and Composite Properties

    Science.gov (United States)

    Smith, Joseph G.; Connell, John W.; Li, Chao-Jun; Wu, Wei; Criss, Jim M., Jr.

    2004-01-01

    PETI-298 is a high temperature/high performance matrix resin that is processable into composites by resin transfer molding (RTM), resin infusion and vacuum assisted RTM techniques. It is typically synthesized in a polar aprotic solvent from the reaction of an aromatic anhydride and a combination of diamines and endcapped with phenylethynylphthalic anhydride. Microwave synthesis of PETI-298 was investigated as a means to eliminate solvent and decrease reaction time. The monomers were manually mixed and placed in a microwave oven for various times to determine optimum reaction conditions. The synthetic process was subsequently scaled-up to 330g. Three batches were synthesized and combined to give 1 kg of material that was characterized for thermal and rheological properties and compared to PETI-298 prepared by the classic solution based synthetic method. The microwave synthesized PETI-298 was subsequently used to fabricate flat laminates on T650 carbon fabric by RTM. The composite panels were analyzed and mechanical properties determined and compared with those fabricated from PETI-298 prepared by the classic solution method. The microwave synthesis process and characterization of neat resin and carbon fiber reinforced composites fabricated by RTM will be presented. KEY WORDS: Resin Transfer Molding, High Temperature Polymers, Phenylethynyl Terminated Imides, Microwave Synthesis

  11. Resin infusion of large composite structures modeling and manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Loos, A.C. [Michigan State Univ., Dept. of Mechanical Engineering, East Lansing, MI (United States)

    2006-07-01

    The resin infusion processes resin transfer molding (RTM), resin film infusion (RFI) and vacuum assisted resin transfer molding (VARTM) are cost effective techniques for the fabrication of complex shaped composite structures. The dry fibrous preform is placed in the mold, consolidated, resin impregnated and cured in a single step process. The fibrous performs are often constructed near net shape using highly automated textile processes such as knitting, weaving and braiding. In this paper, the infusion processes RTM, RFI and VARTM are discussed along with the advantages of each technique compared with traditional composite fabrication methods such as prepreg tape lay up and autoclave cure. The large number of processing variables and the complex material behavior during infiltration and cure make experimental optimization of the infusion processes costly and inefficient. Numerical models have been developed which can be used to simulate the resin infusion processes. The model formulation and solution procedures for the VARTM process are presented. A VARTM process simulation of a carbon fiber preform was presented to demonstrate the type of information that can be generated by the model and to compare the model predictions with experimental measurements. Overall, the predicted flow front positions, resin pressures and preform thicknesses agree well with the measured values. The results of the simulation show the potential cost and performance benefits that can be realized by using a simulation model as part of the development process. (au)

  12. Surface roughness of novel resin composites polished with one-step systems.

    Science.gov (United States)

    Ergücü, Z; Türkün, L S

    2007-01-01

    This study: 1) analyzed the surface roughness of five novel resin composites that contain nanoparticles after polishing with three different one-step systems and 2) evaluated the effectiveness of these polishers and their possible surface damage using scanning electron microscope (SEM) analysis. The resin composites evaluated in this study include CeramX, Filtek Supreme XT, Grandio, Premise and Tetric EvoCeram. A total of 100 discs (20/resin composites, 10 x 2 mm) were fabricated. Five specimens/resin composites cured under Mylar strips served as the control. The samples were polished for 30 seconds with PoGo, OptraPol and One Gloss discs at 15,000 rpm using a slow speed handpiece. The surfaces were tested for roughness (Ra) with a surface roughness tester and examined with SEM. One-way ANOVA was used for statistical analysis (p = 0.05). For all the composites tested, differences between the polishing systems were found to be significant (p One Gloss applications. For Grandio, Mylar and PoGo created equally smooth surfaces, while OptraPol and One Gloss produced equally rougher surfaces. Tetric EvoCeram exhibited the roughest surface with OptraPol, while no significant differences were found between Premise and CeramX. According to SEM images, OptraPol and One Gloss scratched and plucked the particles away from the surface, while PoGo created a uniform finish, although the roughness values were not the same for each composite. Effectiveness of the polishers seems to be material dependent.

  13. [Comparison of surface roughness of nanofilled and microhybrid composite resins after curing and polishing].

    Science.gov (United States)

    Jiang, Hong; Lv, Da; Liu, Kailei; Zhang, Weisheng; Yao, Yao; Liao, Chuhong

    2014-05-01

    To compare the surface roughness of nanofilled dental composite resin and microhybrid composite resins after curing and polishing. A nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from the lateral to the medial layers to prepare 8 mm×8 mm×5 mm cubical specimens. The 4 lateral surfaces of each specimens were polished with abrasive disks (Super-Snap). Profilometer was used to test the mean surface roughness (Ra) after polishing. P60 had the lowest Ra (0.125∓0.030 µm) followed by Z250 and Spectrum. The Ra of Z350 (0.205∓0.052 µm) was greater than that of the other 3 resins, and AP-X had the roughest surfaces. Under scanning electron microscope, the polished faces of P60 resin were characterized by minor, evenly distributed particles with fewer scratches; the polished faces of Z350 presented with scratches where defects of the filling material could be seen. The nanofilled composite Z350 has smooth surface after polishing by abrasive disks, but its smoothness remains inferior to that of other micro-hybrid composite resins.

  14. Monitoring cure of composite resins using frequency dependent electromagnetic sensing techniques

    Science.gov (United States)

    Kranbuehl, D. E.; Hoff, M. S.; Loos, A. C.; Freeman, W. T., Jr.; Eichinger, D. A.

    1988-01-01

    A nondestructive in situ measurement technique has been developed for monitoring and measuring the cure processing properties of composite resins. Frequency dependent electromagnetic sensors (FDEMS) were used to directly measure resin viscosity during cure. The effects of the cure cycle and resin aging on the viscosity during cure were investigated using the sensor. Viscosity measurements obtained using the sensor are compared with the viscosities calculated by the Loos-Springer cure process model. Good overall agreement was obtained except for the aged resin samples.

  15. The bond of different post materials to a resin composite cement and a resin composite core material.

    Science.gov (United States)

    Stewardson, D; Shortall, A; Marquis, P

    2012-01-01

    To investigate the bond of endodontic post materials, with and without grit blasting, to a resin composite cement and a core material using push-out bond strength tests. Fiber-reinforced composite (FRC) posts containing carbon (C) or glass (A) fiber and a steel (S) post were cemented into cylinders of polymerized restorative composite without surface treatment (as controls) and after grit blasting for 8, 16, and 32 seconds. Additional steel post samples were sputter-coated with gold before cementation to prevent chemical interaction with the cement. Cylindrical composite cores were bonded to other samples. After sectioning into discs, bond strengths were determined using push-out testing. Profilometry and electron microscopy were used to assess the effect of grit blasting on surface topography. Mean (standard deviation) bond strength values (MPa) for untreated posts to resin cement were 8.41 (2.80) for C, 9.61(1.88) for A, and 19.90 (3.61) for S. Prolonged grit blasting increased bond strength for FRC posts but produced only a minimal increase for S. After 32 seconds, mean values were 20.65 (4.91) for C, 20.41 (2.93) for A, and 22.97 (2.87) for S. Gold-coated steel samples produced the lowest bond strength value, 7.84 (1.40). Mean bond strengths for untreated posts bonded to composite cores were 6.19 (0.95) for C, 13.22 (1.61) for A, and 8.82 (1.18) for S, and after 32 seconds of grit blasting the values were 17.30 (2.02) for C, 26.47 (3.09) for A, and 20.61 (2.67) for S. FRC materials recorded higher roughness values before and after grit blasting than S. With prolonged grit blasting, roughness increased for A and C, but not for S. There was no evidence of significant bonding to untreated FRC posts, but significant bonding occurred between untreated steel posts and the resin cement. Increases in the roughness of FRC samples were material dependent and roughening significantly increased bond strength values (p<0.05). Surface roughening of the tested FRC posts is

  16. Reducing composite restoration polymerization shrinkage stress through resin modified glass-ionomer based adhesives.

    Science.gov (United States)

    Naoum, S J; Mutzelburg, P R; Shumack, T G; Thode, Djg; Martin, F E; Ellakwa, A E

    2015-12-01

    The aim of this study was to determine whether employing resin modified glass-ionomer based adhesives can reduce polymerization contraction stress generated at the interface of restorative composite adhesive systems. Five resin based adhesives (G Bond, Optibond-All-in-One, Optibond-Solo, Optibond-XTR and Scotchbond-Universal) and two resin modified glass-ionomer based adhesives (Riva Bond-LC, Fuji Bond-LC) were analysed. Each adhesive was applied to bond restorative composite Filtek-Z250 to opposing acrylic rods secured within a universal testing machine. Stress developed at the interface of each adhesive-restorative composite system (n = 5) was calculated at 5-minute intervals over 6 hours. The resin based adhesive-restorative composite systems (RBA-RCS) demonstrated similar interface stress profiles over 6 hours; initial rapid contraction stress development (0-300 seconds) followed by continued contraction stress development ≤0.02MPa/s (300 seconds - 6 hours). The interface stress profile of the resin modified glass-ionomer based adhesive-restorative composite systems (RMGIBA-RCS) differed substantially to the RBA-RCS in several ways. Firstly, during 0-300 seconds the rate of contraction stress development at the interface of the RMGIBA-RCS was significantly (p adhesives can significantly reduce the magnitude and rate of polymerization contraction stress developed at the interface of adhesive-restorative composite systems. © 2015 Australian Dental Association.

  17. Interaction of LED light with coinitiator-containing composite resins: effect of dual peaks.

    Science.gov (United States)

    Sim, Jae-Seong; Seol, Hyo-Joung; Park, Jeong-Kil; Garcia-Godoy, Franklin; Kim, Hyung-Il; Kwon, Yong Hoon

    2012-10-01

    Recently the colour stability of composite resins has been an issue due to the emphasis on the aesthetics of restored teeth. The purpose of the present study was to investigate how dual-peak LED units affect the polymerization of coinitiator-containing composite resins. Five composite resins [coinitiator-containing: Aelite LS Posterior (AL), Tetric EvoCeram (TE), and Vit-l-escence (VI); only CQ-containing: Grandio (GD) and Filtek Z350 (Z3)] were light cured using four different light-curing units (LCUs). Among them, Bluephase G2 (BP) and G-light (GL) were dual-peak LED LCUs. Microhardness, polymerization shrinkage, flexural, and compressive properties were measured. BP and GL had no consistent effect on the microhardness of AL, TE, and VI on the top and bottom surfaces of resin specimens. Among the specimens, AL and VI showed the least (9.86-10.41 μm) and greatest (17.58-19.21 μm) polymerization shrinkage, respectively. However, the effect of BP and GL on the shrinkage of specimens was not consistent. Among the specimens, GD showed the greatest flexural properties [strength (FS) and modulus (FM)] and TE showed the lowest flexural and compressive properties [strength (CS) and modulus (CM)]. In same resin product, maximum FS and CS differences due to the different LCUs were 10.3-21.0% and 3.6-9.2%, respectively. Furthermore, the influences of BP and GL on FS and CS were not consistent. The tested dual-peak LED LCUs had no consistent synergic effect on the polymerization of coinitiator-containing composite resins as compared with QTH and single-peak LED LCUs. The dual-peak LED LCUs achieve a similar degree of polymerization in coinitiator-composite resins as QTH and single-peak LED LCUs did. Choice of LCU does not appear to be a determinant of the light curing of coinitiator-composite resins. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. A comparative effect of various surface chemical treatments on the resin composite-composite repair bond strength

    Directory of Open Access Journals (Sweden)

    Shaloo Gupta

    2015-01-01

    Full Text Available Aim: The aim of this in vitro study was an attempt to investigate the effect of different surface treatments on the bond strength between pre-existing composite and repair composite resin. Materials and Methods: Forty acrylic blocks were prepared in a cuboidal mould. In each block, a well of 5 mm diameter and 5 mm depth was prepared to retain the composite resin (Filtek™ Z350, 3M/ESPE. Aging of the composite discs was achieved by storing them in water at 37°C for 1 week, and after that were divided into 5 groups (n = 8 according to surface treatment: Group I- 37% phosphoric acid, Group II-10% hydrofluoric acid, Group III-30% citric acid, Group IV-7% maleic acid and Group V- Adhesive (no etchant. The etched surfaces were rinsed and dried followed by application of bonding agent (Adper™ Single Bond 2. 3M/ESPE. The repair composite was placed on aged composite, light-cured for 40 seconds and stored in water at 37°C for 1 week. Shear bond strength between the aged and the new composite resin was determined with a universal testing machine (crosshead speed of 0.5 mm/min. Statistical Analysis: The compressive shear strengths were compared for differences using ANOVA test followed by Tamhane′s T2 post hoc analysis. Results: The surface treatment with 10% hydrofluoric acid showed the maximum bond strength followed by 30% citric acid, 7% maleic acid and 37% phosphoric acid in decreasing order. Conclusion: The use of 10% hydrofluoric acid can be a good alternative for surface treatment in repair of composite resin restoration as compared to commonly used 37% orthophosphoric acid.

  19. Surface roughness of composite resin veneer after application of herbal and non-herbal toothpaste

    Science.gov (United States)

    Nuraini, S.; Herda, E.; Irawan, B.

    2017-08-01

    The aim of this study was to find out the surface roughness of composite resin veneer after brushing. In this study, 24 specimens of composite resin veneer are divided into three subgroups: brushed without toothpaste, brushed with non-herbal toothpaste, and brushed with herbal toothpaste. Brushing was performed for one set of 5,000 strokes and continued for a second set of 5,000 strokes. Roughness of composite resin veneer was determined using a Surface Roughness Tester. The results were statistically analyzed using Kruskal-Wallis nonparametric test and Post Hoc Mann-Whitney. The results indicate that the highest difference among the Ra values occurred within the subgroup that was brushed with the herbal toothpaste. In conclusion, the herbal toothpaste produced a rougher surface on composite resin veneer compared to non-herbal toothpaste.

  20. Does the light source affect the repairability of composite resins?

    Science.gov (United States)

    Karaman, Emel; Gönülol, Nihan

    2014-01-01

    The aim of this study was to examine the effect of the light source on the microshear bond strength of different composite resins repaired with the same substrate. Thirty cylindrical specimens of each composite resin--Filtek Silorane, Filtek Z550 (3M ESPE), Gradia Direct Anterior (GC), and Aelite Posterior (BISCO)--were prepared and light-cured with a QTH light curing unit (LCU). The specimens were aged by thermal cycling and divided into three subgroups according to the light source used--QTH, LED, or PAC (n = 10). They were repaired with the same substrate and a Clearfil Repair Kit (Kuraray). The specimens were light-cured and aged for 1 week in distilled water at 37 °C. The microshear bond strength and failure modes were assessed. There was no significant difference in the microshear bond strength values among the composite resins, except for the Filtek Silorane group that showed significantly lower bond strength values when polymerized with the PAC unit compared to the QTH or LED unit. In conclusion, previously placed dimethacrylate-based composites can be repaired with different light sources; however, if the composite to be repaired is silorane-based, then using a QTH or LED device may be the best option.

  1. The effect of processing on autohesive strength development in thermoplastic resins and composites

    Science.gov (United States)

    Howes, Jeremy C.; Loos, Alfred C.; Hinkley, Jeffrey A.

    1989-01-01

    In the present investigation of processing effects on the autohesive bond strength of neat polysulfone resin and graphite-reinforced polysulfone-matrix composites measured resin bond strength development in precracked compact tension specimens 'healed' by heating over a contact period at a given temperature. The critical strain energy release rate of refractured composite specimens did not exhibit the strong time or temperature dependence of the neat resin tests; only 80-90 percent of the undamaged fracture energy is recoverable.

  2. Mechanical fatigue degradation of ceramics versus resin composites for dental restorations.

    Science.gov (United States)

    Belli, Renan; Geinzer, Eva; Muschweck, Anna; Petschelt, Anselm; Lohbauer, Ulrich

    2014-04-01

    For posterior partial restorations an overlap of indication exists where either ceramic or resin-based composite materials can be successfully applied. The aim of this study was to compare the fatigue resistance of modern dental ceramic materials versus dental resin composites in order to address such conflicts. Bar specimens of five ceramic materials and resin composites were produced according to ISO 4049 and stored for 14 days in distilled water at 37°C. The following ceramic materials were selected for testing: a high-strength zirconium dioxide (e.max ZirCAD, Ivoclar), a machinable lithium disilicate (e.max CAD, Ivoclar), a pressable lithium disilicate ceramic (e-max Press, Ivoclar), a fluorapatite-based glass-ceramic (e.max Ceram, Ivoclar), and a machinable color-graded feldspathic porcelain (Trilux Forte, Vita). The composite materials selected were: an indirect machinable composite (Lava Ultimate, 3M ESPE) and four direct composites with varying filler nature (Clearfil Majesty Posterior, Kuraray; GrandioSO, Voco; Tetric EvoCeram, Ivoclar-Vivadent; and CeramX Duo, Dentsply). Fifteen specimens were tested in water for initial strength (σin) in 4-point bending. Using the same test set-up, the residual flexural fatigue strength (σff) was determined using the staircase approach after 10(4) cycles at 0.5 Hz (n=25). Weibull parameters σ0 and m were calculated for the σin specimens, whereas the σff and strength loss in percentage were obtained from the fatigue experiment. The zirconium oxide ceramic showed the highest σin and σff (768 and 440 MPa, respectively). Although both lithium disilicate ceramics were similar in the static test, the pressable version showed a significantly higher fatigue resistance after cyclic loading. Both the fluorapatite-based and the feldspathic porcelain showed equivalent initial and cyclic fatigue properties. From the composites, the highest filled direct material Clearfil Majesty Posterior showed superior fatigue performance

  3. Microstructure and mechanical properties of composite resins subjected to accelerated artificial aging.

    Science.gov (United States)

    dos Reis, Andréa Cândido; de Castro, Denise Tornavoi; Schiavon, Marco Antônio; da Silva, Leandro Jardel; Agnelli, José Augusto Marcondes

    2013-01-01

    The aim of this study was to investigate the influence of accelerated artificial aging (AAA) on the microstructure and mechanical properties of the Filtek Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma and Filtek Z100. composite resins. The composites were characterized by Fourier-transform Infrared spectroscopy (FTIR) and thermal analyses (Differential Scanning Calorimetry - DSC and Thermogravimetry - TG). The microstructure of the materials was examined by scanning electron microscopy. Surface hardness and compressive strength data of the resins were recorded and the mean values were analyzed statistically by ANOVA and Tukey's test (α=0.05). The results showed significant differences among the commercial brands for surface hardness (F=86.74, p<0.0001) and compressive strength (F=40.31, p<0.0001), but AAA did not affect the properties (surface hardness: F=0.39, p=0.53; compressive strength: F=2.82, p=0.09) of any of the composite resins. FTIR, DSC and TG analyses showed that resin polymerization was complete, and there were no differences between the spectra and thermal curve profiles of the materials obtained before and after AAA. TG confirmed the absence of volatile compounds and evidenced good thermal stability up to 200 °C, and similar amounts of residues were found in all resins evaluated before and after AAA. The AAA treatment did not significantly affect resin surface. Therefore, regardless of the resin brand, AAA did not influence the microstructure or the mechanical properties.

  4. Processable polyimide adhesive and matrix composite resin

    Science.gov (United States)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Progar, Donald J. (Inventor)

    1990-01-01

    A high temperature polyimide composition prepared by reacting 4,4'-isophthaloyldiphthalic anhydride with metaphenylenediamine is employed to prepare matrix resins, adhesives, films, coatings, moldings, and laminates, especially those showing enhanced flow with retention of mechanical and adhesive properties. It can be used in the aerospace industry, for example, in joining metals to metals or metals to composite structures. One area of application is in the manufacture of lighter and stronger aircraft and spacecraft structures.

  5. A Randomized 10-year Prospective Follow-up of Class II Nanohybrid and Conventional Hybrid Resin Composite Restorations

    DEFF Research Database (Denmark)

    van Dijken, Jan Wv; Pallesen, Ulla

    2014-01-01

    Purpose: To evaluate the 10-year durability of a nanohybrid resin composite in Class II restorations in a randomized controlled intraindividual comparison with its conventional hybrid resin composite predecessor. Materials and Methods: Each of 52 participants received at least two Class II...... restorations that were as similar as possible. The cavities were chosen at random to be restored with a nanohybrid resin composite (Excite/Tetric EvoCeram (TEC); n = 61) and a conventional hybrid (Excite/Tetric Ceram (TC); n = 61). The restorations were evaluated with slightly modified USPHS criteria...... investigated resin composites. Conclusion: The nanohybrid and the conventional hybrid resin composite showed good clinical effectiveness in extensive Class II restorations during the 10-year study....

  6. Tensile bond strength of indirect composites luted with three new self-adhesive resin cements to dentin

    Directory of Open Access Journals (Sweden)

    Cafer Türkmen

    2011-08-01

    Full Text Available OBJECTIVE: The aims of this study were to evaluate the tensile bond strengths between indirect composites and dentin of 3 recently developed self-adhesive resin cements and to determine mode of failure by SEM. MATERIAL AND METHODS: Exposed dentin surfaces of 70 mandibular third molars were used. Teeth were randomly divided into 7 groups: Group 1 (control group: direct composite resin restoration (Alert with etch-and-rinse adhesive system (Bond 1 primer/adhesive, Group 2: indirect composite restoration (Estenia luted with a resin cement (Cement-It combined with the same etch-and-rinse adhesive, Group 3: direct composite resin restoration with self-etch adhesive system (Nano-Bond, Group 4: indirect composite restoration luted with the resin cement combined with the same self-etch adhesive, Groups 5-7: indirect composite restoration luted with self-adhesive resin cements (RelyX Unicem, Maxcem, and Embrace WetBond, respectively onto the non-pretreated dentin surfaces. Tensile bond strengths of groups were tested with a universal testing machine at a constant speed of 1 mm/min using a 50 kgf load cell. Results were statistically analyzed by the Student's t-test. The failure modes of all groups were also evaluated. RESULTS: The indirect composite restorations luted with the self-adhesive resin cements (groups 5-7 showed better results compared to the other groups (p0.05. The surfaces of all debonded specimens showed evidence of both adhesive and cohesive failure. CONCLUSION: The new universal self-adhesive resins may be considered an alternative for luting indirect composite restorations onto non-pretreated dentin surfaces.

  7. Development of a novel oxirane-acrylate composite restorative resin material

    Science.gov (United States)

    Sripathi Panditaradhyula, Anuhya

    The need for resin with a long clinical life can be satiated through the novel formulation of varying concentrations of oxirane and acrylate monomers with an increase in filler loading in the sample, which will allow the creation of a resin that is less susceptible to chemical degradation along with improved mechanical properties. Various concentrations of oxirane and acrylate monomers with a three-component photoinitiation system, which is capable of both free radical (acrylate) and cationic (oxirane) initiation, are used. The resin composites were placed in the Speedmixer for 30 seconds and gravitation convection oven for one minute, repeated 5-7 times. The resin composites were used to create a 9.525 mm diameter * 1.5875 mm thick resin mold. The mold was then photocured for twenty seconds on both sides using VALO blue LED light. The Rockwell hardness and shore D durometer hardness served as relative measures of bonding between the monomers. The ideal formulation of oxirane and acrylate concentrations were used to perform the Instron 3 point bend test, as well as contact angle determination. The goal is to identify a resin with a clinical life twice that of the resins being used in practice. Potential findings include ideal oxirane and acrylate concentrations with the highest shore D durometer hardness, Rockwell hardness, contact angle values, and Instron 3 point bend test values. Ideal color, transparency and properties of the resin are taken into account. Optimization of oxirane and acrylate monomers, impact while using various filler components (salination, number of fillers), filler particle size variations and variations in using different filler concentrations are observed. Results of using micro and nano-sized monomers are also studied. Addition of fluorinated acrylate monomer to the micro and nano composite was the next goal. A comparison of all the above stated compositions to the control group 70/30 BisTEG was done. A study on the degradation behavior

  8. Surface roughness of composite resins subjected to hydrochloric acid.

    Science.gov (United States)

    Roque, Ana Carolina Cabral; Bohner, Lauren Oliveira Lima; de Godoi, Ana Paula Terossi; Colucci, Vivian; Corona, Silmara Aparecida Milori; Catirse, Alma Blásida Concepción Elizaur Benitez

    2015-01-01

    The purpose of this study was to determine the influence of hydrochloric acid on surface roughness of composite resins subjected to brushing. Sixty samples measuring 2 mm thick x 6 mm diameter were prepared and used as experimental units. The study presented a 3x2 factorial design, in which the factors were composite resin (n=20), at 3 levels: microhybrid composite (Z100), nanofilled composite (FiltekTM Supreme), nanohybrid composite (Ice), and acid challenge (n=10) at 2 levels: absence and presence. Acid challenge was performed by immersion of specimens in hydrochloric acid (pH 1.2) for 1 min, 4 times per day for 7 days. The specimens not subjected to acid challenge were stored in 15 mL of artificial saliva at 37 oC. Afterwards, all specimens were submitted to abrasive challenge by a brushing cycle performed with a 200 g weight at a speed of 356 rpm, totaling 17.8 cycles. Surface roughness measurements (Ra) were performed and analyzed by ANOVA and Tukey test (p≤0.05). Surface roughness values were higher in the presence (1.07±0.24) as compared with the absence of hydrochloric acid (0.72±0.04). Surface roughness values were higher for microhybrid (1.01±0.27) compared with nanofilled (0.68 ±0.09) and nanohybrid (0.48±0.15) composites when the specimens were not subjects to acid challenge. In the presence of hydrochloric acid, microhybrid (1.26±0.28) and nanofilled (1.18±0,30) composites presents higher surface roughness values compared with nanohybrid (0.77±0.15). The hydrochloric acid affected the surface roughness of composite resin subjected to brushing.

  9. Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

    International Nuclear Information System (INIS)

    Milly, Hussam; Andiappan, Manoharan; Thompson, Ian; Banerjee, Avijit

    2014-01-01

    The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

  10. Bacterial adhesion on direct and indirect dental restorative composite resins: An in vitro study on a natural biofilm.

    Science.gov (United States)

    Derchi, Giacomo; Vano, Michele; Barone, Antonio; Covani, Ugo; Diaspro, Alberto; Salerno, Marco

    2017-05-01

    Both direct and indirect techniques are used for dental restorations. Which technique should be preferred or whether they are equivalent with respect to bacterial adhesion is unclear. The purpose of this in vitro study was to determine the affinity of bacterial biofilm to dental restorative composite resins placed directly and indirectly. Five direct composite resins for restorations (Venus Diamond, Adonis, Optifil, Enamel Plus HRi, Clearfil Majesty Esthetic) and 3 indirect composite resins (Gradia, Estenia, Signum) were selected. The materials were incubated in unstimulated whole saliva for 1 day. The biofilms grown were collected and their bacterial cells counted. In parallel, the composite resin surface morphology was analyzed with atomic force microscopy. Both bacterial cell count and surface topography parameters were subjected to statistical analysis (α=.05). Indirect composite resins showed significantly lower levels than direct composite resins for bacterial cell adhesion, (Pcomposite resins (P>.05). However, within the indirect composite resins a significantly lower level was found for Gradia than Estenia or Signum (Pcomposite resin roughness and bacterial adhesion when the second and particularly the third-order statistical moments of the composite resin height distributions were considered. Indirect dental restorative composite resins were found to be less prone to biofilm adhesion than direct composite resins. A correlation of bacterial adhesion to surface morphology exists that is described by kurtosis; thus, advanced data analysis is required to discover possible insights into the biologic effects of morphology. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  11. Comparative study between the radiopacity levels of high viscosity and of flowable composite resins, using digital imaging.

    Science.gov (United States)

    Arita, Emiko S; Silveira, Gilson P; Cortes, Arthur R; Brucoli, Henrique C

    2012-01-01

    The development of countless types and trends of high viscosite and flowable composite resins, with different physical and chemical properties applicable to their broad use in dental clinics calls for further studies regarding their radiopacity level. The aim of this study was to evaluate the radiopacity levels of high viscosity and the flowable composite resins, using digital imaging. 96 composite resin discs 5 mm in diameter and 3 mm thick were radiographed and analyzed. The image acquisition system used was the Digora® Phosphor Storage System and the images were analyzed with the Digora software for Windows. The exposure conditions were: 70 kVp, 8 mA, and 0.2 s. The focal distance was 40 cm. The image densities were obtained with the pixel values of the materials in the digital image. Most of the high viscosity composite resins presented higher radiopacity levels than the flowable composite resins, with statistically significant differences between the trends and groups analyzed (P composite resins, Tetric®Ceram presented the highest radiopacity levels and Glacier® presented the lowest. Among the flowable composite resins, Tetric®Flow presented the highest radiopacity levels and Wave® presented the lowest.

  12. Characterization of water sorption, solubility, and roughness of silorane- and methacrylate-based composite resins.

    Science.gov (United States)

    Giannini, M; Di Francescantonio, M; Pacheco, R R; Cidreira Boaro, L C; Braga, R R

    2014-01-01

    The objective of this study was to evaluate the surface roughness (SR), water sorption (WS), and solubility (SO) of four composite resins after finishing/polishing and after one year of water storage. Two low-shrinkage composites (Filtek Silorane [3M ESPE] and Aelite LS [Bisco Inc]) and two composites of conventional formulations (Heliomolar and Tetric N-Ceram [Ivoclar Vivadent]) were tested. Their respective finishing and polishing systems (Sof-Lex Discs, 3M ESPE; Finishing Discs Kit, Bisco Inc; and Astropol F, P, HP, Ivoclar Vivadent) were used according to the manufacturers' instructions. Ten disc-shaped specimens of each composite resin were made for each evaluation. Polished surfaces were analyzed using a profilometer after 24 hours and one year. For the WS and SO, the discs were stored in desiccators until constant mass was achieved. Specimens were then stored in water for seven days or one year, at which time the mass of each specimen was measured. The specimens were dried again and dried specimen mass determined. The WS and SO were calculated from these measurements. Data were analyzed by two-way analysis of variance and Tukey post hoc test (α=0.05). Filtek Silorane showed the lowest SR, WS, and SO means. Water storage for one year increased the WS means for all composite resins tested. The silorane-based composite resin results were better than those obtained for methacrylate-based resins. One-year water storage did not change the SR and SO properties in any of the composite resins.

  13. Polyimide Composites Properties of RTM370 Fabricated by Vacuum Assisted Resins Transfer Molding (VARTM)

    Science.gov (United States)

    Chuang, Kathy C.; Criss, Jim M.; Mintz, Eric A.

    2011-01-01

    RTM370 imide resin based on 2,3,3 ,4 -biphenyl dianhydride ( a-BPDA), 3,4 -oxydianinline (3,4 -ODA) with 4-phenylethynylphthalic (PEPA) endcap has shown to exhibit high Tg (370 C) and low melt viscosity (10-30 poise) at 280 C with a pot-life of 1-2 h. Previously, RTM370 resin has been fabricated into composites with T650-35 carbon fabrics by resin transfer molding (RTM) successfully. RTM370 composites exhibit excellent mechanical properties up to 327 C (620 F), and outstanding property retention after aging at 288 C (550 F) for 1000 hrs. In this presentation, RTM 370 composites will be fabricated by vacuum assisted resins transfer molding (VARTM), using vacuum bags without mold. The mechanical properties of RTM370 composites fabricated by VARTM will be compared to those of RTM370 made by RTM.

  14. Posterior bulk-filled resin composite restorations. A 5-year randomized controlled clinical study

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2016-01-01

    mm as needed to fill the cavity 2 mm short of the occlusal cavosurface. The occlusal part was completed with the nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2 mm increments. The restorations were evaluated using slightly......, 4 SDR-CeramX mono+ and 6 CeramX mono +-only restorations. The main reasons for failure were tooth fracture (6) and secondary caries (4). The annual failure rate (AFR) for all restorations (Class I and II) was for the bulk-filled-1.1% and for the resin composite-only restorations 1.3% (p = 0...

  15. [Effect of thermal cycling on surface microstructure of different light-curing composite resins].

    Science.gov (United States)

    Lv, Da; Liu, Kai-Lei; Yao, Yao; Zhang, Wei-Sheng; Liao, Chu-Hong; Jiang, Hong

    2015-04-01

    To evaluate the effect of thermal cycling on surface microstructure of different light-curing composite resins. A nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from lateral to center to form cubic specimens. The lateral surfaces were abrased and polished before water storage and 40 000 thermal cycles (5/55 degrees celsius;). The mean surface roughness (Ra) were measured and compared before and after thermal cycling, and the changes of microstructure were observed under scanning electron microscope (SEM). Significant decreases of Ra were observed in the composites, especially in Spectrum (from 0.164±0.024 µm to 0.140±0.017 µm, Presins, and fissures occurred on Z350 following the thermal cycling. Water storage and thermal cycling may produce polishing effect on composite resins and cause fissures on nanofilled composite resins.

  16. A 24-month evaluation of amalgam and resin-based composite restorations

    DEFF Research Database (Denmark)

    McCracken, Michael S; Gordan, Valeria V; Litaker, Mark S

    2013-01-01

    Knowing which factors influence restoration longevity can help clinicians make sound treatment decisions. The authors analyzed data from The National Dental Practice-Based Research Network to identify predictors of early failures of amalgam and resin-based composite (RBC) restorations.......Knowing which factors influence restoration longevity can help clinicians make sound treatment decisions. The authors analyzed data from The National Dental Practice-Based Research Network to identify predictors of early failures of amalgam and resin-based composite (RBC) restorations....

  17. Effect of mechanical properties of fillers on the grindability of composite resin adhesives.

    Science.gov (United States)

    Iijima, Masahiro; Muguruma, Takeshi; Brantley, William A; Yuasa, Toshihiro; Uechi, Jun; Mizoguchi, Itaru

    2010-10-01

    The purpose of this study was to investigate the effect of filler properties on the grindability of composite resin adhesives. Six composite resin products were selected: Transbond XT (3M Unitek, Monrovia, Calif), Transbond Plus (3M Unitek), Enlight (Ormco, Glendora, Calif), Kurasper F (Kuraray Medical, Tokyo, Japan), Beauty Ortho Bond (Shofu, Kyoto, Japan), and Beauty Ortho Bond Salivatect (Shofu). Compositions and weight fractions of fillers were determined by x-ray fluorescence analysis and ash test, respectively. The polished surface of each resin specimen was examined with a scanning electron microscope. Vickers hardness of plate specimens (15 × 10 × 3 mm) was measured, and nano-indentation was performed on large filler particles (>10 μm). Grindability for a low-speed tungsten-carbide bur was estimated. Data were compared with anlaysis of variance (ANOVA) and the Tukey multiple range test. Relationships among grindability, filler content, filler nano-indentation hardness (nano-hardness), filler elastic modulus, and Vickers hardness of the composite resins were investigated with the Pearson correlation coefficient test. Morphology and filler size of these adhesives showed great variations. The products could be divided into 2 groups, based on composition, which affected grindability. Vickers hardness of the adhesives did not correlate (r = 0.140) with filler nano-hardness, which showed a significant negative correlation (r = -0.664) with grindability. Filler nano-hardness greatly influences the grindability of composite resin adhesives. Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  18. Double Vacuum Bag Process for Resin Matrix Composite Manufacturing

    Science.gov (United States)

    Hou, Tan-Hung (Inventor); Jensen, Brian J. (Inventor)

    2007-01-01

    A double vacuum bag molding assembly with improved void management and laminate net shape control which provides a double vacuum enviromnent for use in fabricating composites from prepregs containing air and/or volatiles such as reactive resin matrix composites or composites from solvent containing prepregs with non-reactive resins matrices. By using two vacuum environments during the curing process, a vacuum can be drawn during a B-stage of a two-step cycle without placing the composite under significant relative pressure. During the final cure stage, a significant pressure can be applied by releasing the vacuum in one of the two environments. Inner and outer bags are useful for creating the two vacuum environments with a perforated tool intermediate the two. The composite is placed intermediate a tool plate and a caul plate in the first environment with the inner bag and tool plate defining the first environment. The second environment is characterized by the outer bag which is placed over the inner bag and the tool plate.

  19. Manufacturing of kevlar/polyester composite by resin transfer moulding using conventional and microwave heating

    International Nuclear Information System (INIS)

    Abdullah, I.

    2015-01-01

    Microwave heating was incorporated into the resin transfer moulding technique. Polytetrafluoroethylene (PTFE) mould was used to cure the composite panel. Through the use of microwave heating, the mechanical and physical properties of produced Kevlar fibre/polyester composites were compared to those manufactured by conventional resin transfer moulding. The flexural modulus and flexural strength of 6-ply conventionally cured composites was 45% and 9% higher than the flexural modulus and flexural strength of 6-ply microwaved cured composites, respectively. However, 19% increase in interlaminar shear strength (ILSS) and 2% increase in compressive strength was observed in 6-ply microwave cured composites. This enhancement in ILSS and compressive strength is attributed to the better interfacial bonding of polyester resin with Kevlar fibres in microwaved cured composite, which was also confirmed via electron microscopy scanning. Furthermore, the microwave cured composite yielded maximum void contents (3%). (author)

  20. Efficacy of polishing kits on the surface roughness and color stability of different composite resins.

    Science.gov (United States)

    Kocaagaoglu, H; Aslan, T; Gürbulak, A; Albayrak, H; Taşdemir, Z; Gumus, H

    2017-05-01

    Different polishing kits may have different effects on the composite resin surfaces. The aim of this study was to evaluate the surface roughness and color stability of four different composites which was applied different polishing technique. Thirty specimens were made for each composite resin group (nanohybrid, GrandioSo-GS; nanohybrid, Clearfil Majesty Esthetic-CME; hybrid, Valux Plus-VP; micro-hybrid, Ruby Comp-RC; [15 mm in diameter and 2 mm height]), with the different monomer composition and particle size from a total of 120 specimens. Each composite group was divided into three subgroups (n = 10). The first subgroup of the each composite subgroups served as control (C) and had no surface treatment. The second subgroup of the each composite resin groups was polished with finishing discs (Bisco Finishing Discs; Bisco Inc., Schaumburg, IL, USA). The third subgroup of the each composite resin was polished with polishing wheel (Enhance and PoGo, Dentsply, Konstanz, Germany). The surface roughness and the color differences measurement of the specimens were made and recorded. The data were compared using Kruskal-Wallis test, and regression analysis was used in order to examine the correlation between surface roughness and color differences of the specimens (α = 0.05). The Kruskal-Wallis test indicated significant difference among the composite resins in terms of ΔE (P composite resins in terms of surface roughness (P > 0.05). Result of the regression analysis indicated statistically significant correlation between Ra and ΔE values (P < 0.05, r2 = 0.74). The findings of the present study have clinical relevance in the choice of polishing kits used.

  1. Composite Properties of RTM370 Polyimide Fabricated by Vacuum Assisted Resin Transfer Molding (VARTM)

    Science.gov (United States)

    Chuang, Kathy C.; Criss, James M.; Mintz, Eric A.; Shonkwiler, Brian; McCorkle, Linda S.

    2011-01-01

    RTM370 imide resin based on 2,3,3?,4?-biphenyl dianhydride (a-BPDA), 3,4'-oxydianinline (3,4'-ODA) with the 4-phenylethynylphthalic (PEPA) endcap has been shown to exhibit a high cured T(sub g) (370 C) and low melt viscosity (10-30 poise) at 280 C with a pot-life of 1-2 h. Previously, RTM370 resin has been successfully fabricated into composites reinforced with T650-35 carbon fabrics by resin transfer molding (RTM). RTM370 composites exhibit excellent mechanical properties up to 327?C (620?F), and outstanding property retention after aging at 288?C (550?F) for 1000 h. In this work, RTM370 composites were fabricated by vacuum assisted resin transfer molding (VARTM), using vacuum bags on a steel plate. The mechanical properties of RTM370 composites fabricated by VARTM are compared to those prepared by RTM.

  2. Fracture Resistance of Endodontically Treated Teeth Restored with Biodentine, Resin Modified GIC and Hybrid Composite Resin as a Core Material.

    Science.gov (United States)

    Subash, Dayalan; Shoba, Krishnamma; Aman, Shibu; Bharkavi, Srinivasan Kumar Indu; Nimmi, Vijayan; Abhilash, Radhakrishnan

    2017-09-01

    The restoration of a severely damaged tooth usually needs a post and core as a part of treatment procedure to provide a corono - radicular stabilization. Biodentine is a class of dental material which possess high mechanical properties with excellent biocompatibility and bioactive behaviour. The sealing ability coupled with optimum physical properties could make Biodentine an excellent option as a core material. The aim of the study was to determine the fracture resistance of Biodentine as a core material in comparison with resin modified glass ionomer and composite resin. Freshly extracted 30 human permanent maxillary central incisors were selected. After endodontic treatment followed by post space preparation and luting of Glass fibre post (Reforpost, Angelus), the samples were divided in to three groups based on the type of core material. The core build-up used in Group I was Biodentine (Septodont, France), Group II was Resin-Modified Glass Ionomer Cement (GC, Japan) and Group III was Hybrid Composite Resin (TeEconom plus, Ivoclar vivadent). The specimens were subjected to fracture toughness using Universal testing machine (1474, Zwick/Roell, Germany) and results were compared using One-way analysis of variance with Tukey's Post hoc test. The results showed that there was significant difference between groups in terms of fracture load. Also, composite resin exhibited highest mean fracture load (1039.9 N), whereas teeth restored with Biodentine demonstrated the lowest mean fracture load (176.66 N). Resin modified glass ionomer exhibited intermediate fracture load (612.07 N). The primary mode of failure in Group I and Group II was favourable (100%) while unfavourable fracture was seen in Group III (30%). Biodentine, does not satisfy the requirements to be used as an ideal core material. The uses of RMGIC's as a core build-up material should be limited to non-stress bearing areas. Composite resin is still the best core build-up material owing to its high fracture

  3. Mechanical properties of silorane-based and methacrylate-based composite resins after artificial aging.

    Science.gov (United States)

    de Castro, Denise Tornavoi; Lepri, César Penazzo; Valente, Mariana Lima da Costa; dos Reis, Andréa Cândido

    2016-01-01

    The aim of this study was to compare the compressive strength of a silorane-based composite resin (Filtek P90) to that of conventional composite resins (Charisma, Filtek Z250, Fill Magic, and NT Premium) before and after accelerated artificial aging (AAA). For each composite resin, 16 cylindrical specimens were prepared and divided into 2 groups. One group underwent analysis of compressive strength in a universal testing machine 24 hours after preparation, and the other was subjected first to 192 hours of AAA and then the compressive strength test. Data were analyzed by analysis of variance, followed by the Tukey HSD post hoc test (α = 0.05). Some statistically significant differences in compressive strength were found among the commercial brands (P aging. Comparison of each material before and after AAA revealed that the aging process did not influence the compressive strength of the tested resins (P = 0.785).

  4. Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

    Energy Technology Data Exchange (ETDEWEB)

    Milly, Hussam [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Andiappan, Manoharan [Unit of Dental Public Health, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Thompson, Ian [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Banerjee, Avijit, E-mail: avijit.banerjee@kcl.ac.uk [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Unit of Conservative Dentistry, King' s College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom)

    2014-06-01

    The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

  5. Improvement in char formability of phenolic resin for development of Carbon/Carbon composites

    International Nuclear Information System (INIS)

    Hajhosseini, M.; Payami, A.; Ghaffarian, S. R.; Rezadoust, A. M.

    2008-01-01

    In the processing of carbon/carbon composites using polymer resin as the matrix precursor, it is inevitable that a porous structure was formed after carbonization. As a result, densification by liquid phase impregnation followed by recarbonization is required to obtain a densified composite. Consequently, the char formability of resin is an important factor in reducing the number of densification cycles and hence the processing cost. In this study, a novel approach is adopted to improve the densification of carbon/carbon composites by using a new phenolic resin modified by pitch. For this purpose, soluble part of pitch was extracted and dispersed in resol type phenolic resin. The polymerization reaction was performed in presence of para-formaldehyde and a resol-pitch compound was obtained. The second compound was prepared by mixing novolac-furfural in 55:45 weight ratio containing 9% by weight hexamethylene tetramine. This compound was added to resol-pitch compound in 10,20,50 and 80 w %. The microstructure of carbonized resin was investigated by X-ray diffraction and char yield, and the linear and volumetric shrinkage were obtained. Results show that in 80:20 ratio of resol-pitch to novolac-furfural , the char yield would be maximized by 71% and volumetric shrinkage would be minimized at 16.4%. At the same time, XRD results indicate that the resin has a strong ability to graphitize carbon/carbon composites matrix as a necessary step for its processing

  6. Comparison of stabilities in translucency, fluorescence and opalescence of direct and indirect composite resins.

    Science.gov (United States)

    Yu, Bin; Lee, Young-Keun

    2013-01-01

    To evaluate translucency, fluorescence and opalescence stabilities of direct and indirect composite resins after aging. One direct (16 shades) and two indirect composite resins (16 and 26 shades) were investigated. Resins were filled in a mold (1 mm thick) and light cured; post-curings were performed for indirect resins. Color was measured before and after 5,000 cycles of thermocycling on a reflection spectrophotometer in reflectance and transmittance modes to calculate parameters for translucency (TP), fluorescence (FL) and opalescence (OP). Differences in the changes of TP, FL and OP after aging by the type of resin were determined by t test, and those were also determined by one-way ANOVA with the factor of the brand or the shade group (P resins; and were -2.0 to 1.8, -0.9 to 0.4 and -2.9 to 3.7, respectively, for indirect resins. Changes in TP were not significantly different by the type of resin, but those in FL and OP were different (P = 0.05). Changes in optical parameters were influenced by the brand or the shade group of the resins (P resins varied depending on type, brand or shade group. Aging significantly affected fluorescence and opalescence, but not translucency, of indirect resins compared to those of direct resins.

  7. The effect of time between curing and tea immersion on composite resin discoloration.

    Science.gov (United States)

    Esmaeili, Behnaz; Afkhami, Solaleh; Abolghasemzadeh, Faezeh

    2018-01-01

    One common cause for the replacement of a composite restoration is discoloration. This in vitro study evaluated the effect of tea solution on the discoloration of 3 types of composites at different timepoints after curing. For this study, 150 disc-shaped specimens of 3 types of composite resin-a nanohybrid (Filtek Z350), a microhybrid (Filtek Z250), and a microfilled material (Heliomolar)-were prepared. Specimens were randomly divided into 5 subgroups (n = 10) according to the type of composite and the time from curing to immersion in a tea solution (none [immersed immediately], 1 hour, 6 hours, 12 hours, or 24 hours postcuring). The color for all specimens was measured before and after immersion in tea. Color change (ΔE*) for all specimens was measured, and a ΔE* value of less than 3.3 was considered clinically acceptable. Analysis of variance and a post hoc Tukey test were used to analyze the data (α = 0.05). Immediately after curing, the levels of composite discoloration were deemed clinically acceptable (ΔE* composites, the greatest color change was found immediately after curing (P composite resin specimens was significantly greater than that of Heliomolar specimens (P composite group than in the Heliomolar group (P composites were not significantly different from each other (P > 0.05), except with 12-hour postcure immersion. The results suggest that patients should avoid the intake of staining foods or beverages for at least 12 hours after placement of a composite resin restoration, although this restriction may be reduced to 1 hour for microfilled composite resins.

  8. Effect of water storage on the translucency of silorane-based and dimethacrylate-based composite resins with fibres.

    Science.gov (United States)

    Ozakar Ilday, Nurcan; Celik, Neslihan; Bayindir, Yusuf Ziya; Seven, Nilgün

    2014-06-01

    The purposes of this study were (1) to determine the translucency of silorane and dimethacrylate-based composite resins and (2) to evaluate the effect of water storage and reinforcement with fibre on the translucency of composite resins. Two light-cured composite resins (A2 shade), Filtek Silorane (silorane-based composite) and Valux Plus (dimethacrylate-based composite), were used in this study. The first group was used as the control with no reinforcements, the second was reinforced with polyethylene (Ribbond THM) and the third was reinforced with a glass fibre (Everstick Net) for each composite resin. Colour measurements were measured against white and black backgrounds with a Shadepilot (Degu Dent Gmbh, Hanau, Germany) spectrophotometer and recorded under a D65 light source, which reflects daylight. CIELAB parameters of each specimen were recorded at baseline and at 24 h, 168 h and 504 h. Translucency of materials was calculated using the translucency parameter (TP) formula. Data were analyzed using repeated measures ANOVA and LSD post hoc tests (α=0.05). The highest baseline TP value was in the Valux Plus/non-fibre reinforced group (14.06±1) and the lowest in the Filtek Silorane/Ribond THM group (8.98±1.11). Repeated measures ANOVA revealed significant effects from the factors storage time, composite resin, composite resin×storage time and fibre×time (p=0.047; p=0.001; p=0.013; p=0.022, respectively). Within the limitations of the study, we concluded that inclusion of polyethylene and glass fibres did not alter the translucency of the different-based composite resins. The longest storage time resulted in the greatest change in translucency values of Filtek Silorane composite resins. Considering the translucencies of composites with different formulations in the selection of composite resins for aesthetic restorations is important in terms of obtaining optimal aesthetic outcomes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Marginal Gap Formation in Approximal "Bulk Fill" Resin Composite Restorations After Artificial Ageing.

    Science.gov (United States)

    Peutzfeldt, A; Mühlebach, S; Lussi, A; Flury, S

    The aim of this in vitro study was to investigate the marginal gap formation of a packable "regular" resin composite (Filtek Supreme XTE [3M ESPE]) and two flowable "bulk fill" resin composites (Filtek Bulk Fill [3M ESPE] and SDR [DENTSPLY DeTrey]) along the approximal margins of Class II restorations. In each of 39 extracted human molars (n=13 per resin composite), mesial and distal Class II cavities were prepared, placing the gingival margins below the cemento-enamel junction. The cavities were restored with the adhesive system OptiBond FL (Kerr) and one of the three resin composites. After restoration, each molar was cut in half in the oro-vestibular direction between the two restorations, resulting in two specimens per molar. Polyvinylsiloxane impressions were taken and "baseline" replicas were produced. The specimens were then divided into two groups: At the beginning of each month over the course of six months' tap water storage (37°C), one specimen per molar was subjected to mechanical toothbrushing, whereas the other was subjected to thermocycling. After artificial ageing, "final" replicas were produced. Baseline and final replicas were examined under the scanning electron microscope (SEM), and the SEM micrographs were used to determine the percentage of marginal gap formation in enamel or dentin. Paramarginal gaps were registered. The percentages of marginal gap formation were statistically analyzed with a nonparametric analysis of variance followed by Wilcoxon-Mann-Whitney tests and Wilcoxon signed rank tests, and all p-values were corrected with the Bonferroni-Holm adjustment for multiple testing (significance level: α=0.05). Paramarginal gaps were analyzed descriptively. In enamel, significantly lower marginal gap formation was found for Filtek Supreme XTE compared to Filtek Bulk Fill ( p=0.0052) and SDR ( p=0.0289), with no significant difference between Filtek Bulk Fill and SDR ( p=0.4072). In dentin, significantly lower marginal gap formation was

  10. Direct spectrometry: a new alternative for measuring the fluorescence of composite resins and dental tissues.

    Science.gov (United States)

    da Silva, Tm; de Oliveira, Hpm; Severino, D; Balducci, I; Huhtala, Mfrl; Gonçalves, Sep

    2014-01-01

    The aim of this study was to evaluate the fluorescence intensity of different composite resins and compare those values with the fluorescence intensity of dental tissues. Different composite resins were used to make 10 discs (2 mm in depth and 4 mm in diameter) of each brand, divided into groups: 1) Z (Filtek Z350, 3M ESPE), 2) ES (Esthet-X, Dentsply), 3) A (Amelogen Plus, Ultradent), 4) DVS (Durafill-VS, Heraeus Kulzer) with 2 mm composite resin for enamel (A2), 5) OES ([Esthet-X] opaque-OA [1 mm] + enamel-A2 [1 mm]); 6) ODVSI ([Charisma-Opal/Durafill-VSI], opaque-OM (1 mm) + translucent [1mm]), and 7) DVSI ([Durafill- VSI] translucent [2 mm]). Dental tissue specimens were obtained from human anterior teeth cut in a mesiodistal direction to obtain enamel, dentin, and enamel/dentin samples (2 mm). The fluorescence intensity of specimens was directly measured using an optic fiber associated with a spectrometer (Ocean Optics USB 4000) and recorded in graphic form (Origin 8.0 program). Data were submitted to statistical analysis using Dunnet, Tukey, and Kruskall-Wallis tests. Light absorption of the composite resins was obtained in a spectral range from 250 to 450 nm, and that of dental tissues was between 250 and 300 nm. All composite resins were excited at 398 nm and exhibited maximum emissions of around 485 nm. Fluorescence intensity values for all of the resins showed statistically significant differences (measured in arbitrary units [AUs]), with the exception of groups Z and DVS. Group DVSI had the highest fluorescence intensity values (13539 AU), followed by ODVS (10440 AU), DVS (10146 AU), ES (3946 AU), OES (3841 AU), A (3540 AU), and Z (1146 AU). The fluorescence intensity values for the composite resins differed statistically from those of dental tissues (E=1380 AU; D=6262 AU; E/D=3251 AU). The opacity interfered with fluorescence intensity, and group Z demonstrated fluorescence intensity values closest to that of tooth enamel. It is concluded that the

  11. Influence of staining solutions and whitening procedures on discoloration of hybrid composite resins.

    Science.gov (United States)

    Garoushi, Sufyan; Lassila, Lippo; Hatem, Marwa; Shembesh, Muneim; Baady, Lugane; Salim, Ziad; Vallittu, Pekka

    2013-01-01

    The aim was to evaluate the color stability and water uptake of two hybrid composite resins polymerized in two different conditions after exposure to commonly consumed beverages. In addition, the effect of repolishing and bleaching on the stained composite was evaluated. Eighty specimens (12 mm × 12 mm × 3 mm) were made from two hybrid composite resins of shade A2. Forty specimens of each composite were divided into two groups (n = 20 per each) according to the curing method used (hand light cure HLC or oven light cure OLC). Then each group (HLC or OLC) was sub-divided randomly into four sub-groups (n = 5), which were immersed for 60 days in different beverages (distal water, coffee, tea and pepsi) and incubated at 37°C. Water uptake was measured during this time and followed by measurement of color difference (ΔE) by using a spectrophotometer. After complete staining, repolishing (grit 4000 FEPA at 300 rpm under water) and bleaching (40% hydrogen peroxide bleaching gel) were conducted. The repolished and bleached specimens were submitted to new color measurements. Color value of the specimens immersed in tea displayed the highest statistically significant (p pepsi was significantly lower than the others. After staining of the composite resins, both the bleaching and repolishing were able to reduce the ΔE value. All beverages used affected the color stability of tested composite resins. The effect of beverages on color change of composites depends on type of beverage and water uptake value of resins used. A superior whitening effect was obtained with repolishing technique compared to bleaching.

  12. FT-Raman spectroscopy study of organic matrix degradation in nanofilled resin composite.

    Science.gov (United States)

    Soares, Luís Eduardo Silva; Nahórny, Sídnei; Martin, Airton Abrahão

    2013-04-01

    This in vitro study evaluated the effect of light curing unit (LCU) type, mouthwashes, and soft drink on chemical degradation of a nanofilled resin composite. Samples (80) were divided into eight groups: halogen LCU, HS--saliva (control); HPT--Pepsi Twist®; HLC--Listerine®; HCP--Colgate Plax®; LED LCU, LS--saliva (control); LPT--Pepsi Twist®; LLC--Listerine®; LCP--Colgate Plax®. The degree of conversion analysis and the measure of the peak area at 2,930 cm-1 (organic matrix) of resin composite were done by Fourier-transform Raman spectroscopy (baseline, after 7 and 14 days). The data were subjected to multifactor analysis of variance (ANOVA) at a 95% confidence followed by Tukey's HSD post-hoc test. The DC ranged from 58.0% (Halogen) to 59.3% (LED) without significance. Differences in the peak area between LCUs were found after 7 days of storage in S and PT. A marked increase in the peak intensity of HLC and LLC groups was found. The soft-start light-activation may influence the chemical degradation of organic matrix in resin composite. Ethanol contained in Listerine® Cool Mint mouthwash had the most significant degradation effect. Raman spectroscopy is shown to be a useful tool to investigate resin composite degradation.

  13. Influence of curing rate on softening in ethanol, degree of conversion, and wear of resin composite

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Asmussen, Erik

    2011-01-01

    PURPOSE: To investigate the effect of curing rate on softening in ethanol, degree of conversion, and wear of resin composites. METHOD: With a given energy density and for each of two different light-curing units (QTH or LED), the curing rate was reduced by modulating the curing mode. Thus......, the irradiation of resin composite specimens (Filtek Z250, Tetric Ceram, Esthet-X) was performed in a continuous curing mode and in a pulse-delay curing mode. Wallace hardness was used to determine the softening of resin composite after storage in ethanol. Degree of conversion was determined by infrared...... exposed to the pulse-delay curing mode were softer than resin composites exposed to continuous cure (Pconversion (P

  14. The effect of repeated preheating of dimethacrylate and silorane-based composite resins on marginal gap of class V restorations.

    Science.gov (United States)

    Alizadeh Oskoee, Parnian; Pournaghi Azar, Fatemeh; Jafari Navimipour, Elmira; Ebrahimi Chaharom, Mohammad Esmaeel; Naser Alavi, Fereshteh; Salari, Ashkan

    2017-01-01

    Background. One of the problems with composite resin restorations is gap formation at resin‒tooth interface. The present study evaluated the effect of preheating cycles of silorane- and dimethacrylate-based composite resins on gap formation at the gingival margins of Class V restorations. Methods. In this in vitro study, standard Class V cavities were prepared on the buccal surfaces of 48 bovine incisors. For restorative procedure, the samples were randomly divided into 2 groups based on the type of composite resin (group 1: di-methacrylate composite [Filtek Z250]; group 2: silorane composite [Filtek P90]) and each group was randomly divided into 2 subgroups based on the composite temperature (A: room temperature; B: after 40 preheating cycles up to 55°C). Marginal gaps were measured using a stereomicroscope at ×40 and analyzed with two-way ANOVA. Inter- and intra-group comparisons were analyzed with post-hoc Tukey tests. Significance level was defined at P composite resin type, preheating and interactive effect of these variables on gap formation were significant (Pcomposite resins (Pcomposite resins at room temperature compared to composite resins after 40 preheating cycles (Pcomposite re-sins. Preheating of silorane-based composites can result in the best marginal adaptation.

  15. Terpenoid composition and class of Tertiary resins from India

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Suryendu; Mallick, Monalisa; Mathews, Runcie Paul [Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India); Bertram, Norbert [LTA-Labor fuer Toxikologie und Analytik, Friedrichshoeher Str. 28, D-53639 Koenigswinter (Germany); Greenwood, Paul F. [John De Laeter Mass Spectrometry and WA Biogeochemitry Centres (M090), The University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009 (Australia); WA - Organic and Isotope Geochemistry Centre, Curtin University of Technology, Kent St., Bentley 6102 (Australia)

    2009-10-01

    The terpenoid composition and class of Tertiary resins preserved within lignites of Cambay, Kutch and Cauvery Basins of India have been characterized using Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS) and Fourier Transform Infrared (FTIR) Spectroscopy. Major pyrolysis products include cadalene-based C{sub 15}-bicyclic sesquiterpenoids with some C{sub 30} and C{sub 31} bicadinanes and bicadinenes typical of Class II or dammar resin. The occurrence of these terpenoids in Early Eocene sediments may extend the first appearance of Dipterocarpaceae angiosperms, the predominant source of this resin class, back to the Early Eocene epoch in India. The same terpenoid biomarkers have been detected in many SE Asian oils reflecting a close source relationship with these resins. Strong CH{sub 3} (1377 cm{sup -} {sup 1}) and other CH{sub x} (3000-2800 and 1460-1450 cm{sup -} {sup 1}) aliphatic absorptions of much larger intensity than the aromatic C = C (1560-1650 cm{sup -} {sup 1}) absorption were detected in the Indian resins by FTIR Spectroscopy, confirming the quantitative significance of the terpenoid pyrolysates. (author)

  16. Toothbrushing alters the surface roughness and gloss of composite resin CAD/CAM blocks.

    Science.gov (United States)

    Kamonkhantikul, Krid; Arksornnukit, Mansuang; Lauvahutanon, Sasipin; Takahashi, Hidekazu

    2016-01-01

    This study investigated the surface roughness and gloss of composite resin CAD/CAM blocks after toothbrushing. Five composite resin blocks (Block HC, Cerasmart, Gradia Block, KZR-CAD Hybrid Resin Block, and Lava Ultimate), one hybrid ceramic (Vita Enamic), one feldspar ceramic (Vitablocs Mark II), one PMMA block (Telio CAD), and one conventional composite resin (Filtek Z350 XT) were evaluated. Surface roughness (Ra) and gloss were determined for each group of materials (n=6) after silicon carbide paper (P4000) grinding, 10k, 20k, and 40k toothbrushing cycles. One-way repeated measures ANOVA indicated significant differences in the Ra and gloss of each material except for the Ra of GRA. After 40k toothbrushing cycles, the Ra of BLO and TEL showed significant increases, while CER, KZR, ULT, and Z350 showed significant decreases. GRA, ENA, and VIT maintained their Ra. All of the materials tested, except CER, demonstrated significant decreases in gloss after 40k toothbrushing cycles.

  17. Bonding to new CAD/CAM resin composites: influence of air abrasion and conditioning agents as pretreatment strategy.

    Science.gov (United States)

    Reymus, Marcel; Roos, Malgorzata; Eichberger, Marlis; Edelhoff, Daniel; Hickel, Reinhard; Stawarczyk, Bogna

    2018-04-27

    Because of their industrially standardized process of manufacturing, CAD/CAM resin composites show a high degree of conversion, making a reliable bond difficult to achieve. The purpose of this experiment was to investigate the tensile bond strength (TBS) of luting composite to CAD/CAM resin composite materials as influenced by air abrasion and pretreatment strategies. The treatment factors of the present study were (1) brand of the CAD/CAM resin composite (Brilliant Crios [Coltene/Whaledent], Cerasmart [GC Europe], Shofu Block HC [Shofu], and Lava Ultimate [3M]); (2) air abrasion vs. no air abrasion; and (3) pretreatment using a silane primer (Clearfil Ceramic Primer, Kuraray) vs. a resin primer (One Coat 7 Universal, Coltene/Whaledent). Subsequently, luting composite (DuoCem, Coltene/Whaledent) was polymerized onto the substrate surface using a mold. For each combination of the levels of the three treatment factors (4 (materials) × 2 (air abrasion vs. no air abrasion; resin) × 2 (primer vs. silane primer)), n = 15, specimens were prepared. After 24 h of water storage at 37 °C and 5000 thermo-cycles (5/55 °C), TBS was measured and failure types were examined. The resulting data was analyzed using Kaplan-Meier estimates of the cumulative failure distribution function with Breslow-Gehan tests and non-parametric ANOVA (Kruskal-Wallis test) followed by the multiple pairwise Mann-Whitney U test with α-error adjustment using the Benjamini-Hochberg procedure and chi-square test (p CAD/CAM resin composites, the restorations should be air abraded and pretreated using a resin primer containing methyl-methacrylate to successfully bond to the luting composite. The pretreatment of the CAD/CAM resin composite using merely a silane primer results in deficient adhesion. For a reliable bond of CAD/CAM resin composites to the luting composite, air abrasion and a special pretreatment strategy are necessary in order to achieve promising long-term results.

  18. Effect of organic solvents compared to sandblasting on the repair bond strength of nanohybrid and nanofilled composite resins.

    Science.gov (United States)

    Brum, Rafael Torres; Vieira, Sergio; Freire, Andrea; Mazur, Rui Fernando; De Souza, Evelise Machado; Rached, Rodrigo Nunes

    2017-01-01

    This study evaluated the effect of different surface treatments on the repair bond strength of nanohybrid (Empress Direct) and nanofilled (Filtek Z350 XT) composite resins. A total of 120 specimens of each material (7.5 x 4.5 x 3 mm) were prepared and polished with SiC paper. Half of the specimens were kept in water for seven days and the other half for six months; they were then divided into six groups according to the type of surface treatment: negative control (no treatment), Al2O3sandblasted, liquid acetone, acetone gel, liquid alcohol and alcohol gel. Following application of the silane coupling agent and the adhesive system, composite resin cylinders were fabricated on the specimens and light cured (20 seconds). The same composite resins were used for the repair. Additionally, ten intact specimens of each composite resin (without repair) were prepared (positive control). The specimens were then loaded to failure in the microshear mode. Three additional specimens were fabricated in each group, and the surface treatments were analyzed by atomic force microscopy, energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM). The nanofilled composite resin showed higher cohesive strength and repair bond strength than the nanohybrid composite resin. The aging process affected the repair bond strength of the nanofilled composite resin. Al2O3sandblasting was more efficient for the nanofilled composite resin and promoted greater surface roughness in both materials. The solvents demonstrated higher efficacy for the nanohybrid composite resin. The strengths resulting from the solvents were material dependent, and Al2O3sandblasting resulted in superior repair bond strength in both materials.

  19. Preparation and characterization of silane-modified SiO2 particles reinforced resin composites with fluorinated acrylate polymer.

    Science.gov (United States)

    Liu, Xue; Wang, Zengyao; Zhao, Chengji; Bu, Wenhuan; Na, Hui

    2018-04-01

    A series of fluorinated dental resin composites were prepared with two kinds of SiO 2 particles. Bis-GMA (bisphenol A-glycerolate dimethacrylate)/4-TF-PQEA (fluorinated acrylate monomer)/TEGDMA (triethylene glycol dimethacrylate) (40/30/30, wt/wt/wt) was introduced as resin matrix. SiO 2 nanopartices (30nm) and SiO 2 microparticles (0.3µm) were silanized with 3-methacryloxypropyl trimethoxysilane (γ-MPS) and used as fillers. After mixing the resin matrix with 0%, 10%, 20%, 30% SiO 2 nanopartices and 0%, 10%, 20%, 30%, 40%, 50% SiO 2 microparticles, respectively, the fluorinated resin composites were obtained. Properties including double bond conversion (DC), polymerization shrinkage (PS), water sorption (W p ), water solubility (W y ), mechanical properties and cytotoxicity were investigated in comparison with those of neat resin system. The results showed that, filler particles could improve the overall performance of resin composites, particularly in improving mechanical properties and reducing PS of composites along with the addition of filler loading. Compared to resin composites containing SiO 2 microparticles, SiO 2 nanoparticles resin composites had higher DC, higher mechanical properties, lower PS and lower W p under the same filler content. Especially, 50% SiO 2 microparticles reinforced resins exhibited the best flexural strength (104.04 ± 7.40MPa), flexural modulus (5.62 ± 0.16GPa), vickers microhardness (37.34 ± 1.13 HV), compressive strength (301.54 ± 5.66MPa) and the lowest polymerization (3.42 ± 0.22%). Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Bond strength of a composite resin to glass ionomer cements using different adhesive systems

    Directory of Open Access Journals (Sweden)

    Ana Carolina de Oliveira BECCI

    2017-08-01

    Full Text Available Abstract Introduction Glass ionomer cements are often used as a base or cavity lining prior to restorative material. Objective To evaluate the bond strength of a composite resin to different glass ionomer cements, when using a two-step conventional and self-etching adhesive systems. Material and method Three glass ionomer cements (Ketac Molar Easymix, Vitremer and Vitrebond, the composite resin Filtek Z350 XT and the adhesive systems Adper Single Bond 2, Clearfil SE Bond and Adper Easy One were used. As negative control, resin was bonded to cement without using an adhesive system. Holes (4 mm diameter, 2 mm deep prepared in acrilic bloks were filled with the glass ionomer cements (n=12/group. On the surface, an area of 1mm in diameter was delimited, the adhesive system was applied, and a specimen of composite resin with 1 mm height was made. After 24 hours storage (37 °C and 100% humidity, the microshear test was performed. Data were analyzed using two-way ANOVA and Tukey test for comparison between groups (α=0.05. Result The adhesive systems significantly improved the bond strenght of composite resin to glass ionomer cements (p≤0.001. There was no significant difference in bond strength when self-etching adhesive systems were compared with the simplified etch-and-rinse adhesive, except for Vitrebond where Clearfil SE Bond determined higher bond strength when compared to Adper Single Bond 2 (p=0.003. Conclusion Self-etching adhesive systems are a good option for establishing the bond between the composite resin and the glass ionomer cement.

  1. SEM/XPS analysis of fractured adhesively bonded graphite fibre surface resin-rich/graphite fibre composites

    Science.gov (United States)

    Devilbiss, T. A.; Wightman, J. P.; Progar, D. J.

    1988-01-01

    Samples of graphite fiber-reinforced polyimide were fabricated allowing the resin to accumulate at the composite surface. These surface resin-rich composites were then bonded together and tested for lap shear strength both before and after thermal aging. Lap shear strength did not appear to show a significant improvement over that previously recorded for resin-poor samples and was shown to decrease with increasing aging time and temperature.

  2. Effect of resin composition to the electrical and mechanical properties of high voltage insulator material

    International Nuclear Information System (INIS)

    Totok Dermawan; Elin Nuraini; Suyamto

    2012-01-01

    A solid insulator manufacture of resins for high voltage with a variation of resin and hardener composition has been made. The purpose of research to know electrical and mechanical properties of high voltage insulator material of resin. To determine its electric properties, the material is tested its breakdown voltage and the flashover voltage that occurred on the surface. While to determine the mechanical properties were tested by measuring its strength with a tensile test. From testing with variety of mixed composition it is known that for composition between hardener and resin of 1 : 800 has most advantageous properties because it has good strength with a tensile strength of 19.86 MPa and enough high dielectric strength of 43.2 kV / mm). (author)

  3. Effects of polishing on surface roughness, gloss, and color of resin composites.

    Science.gov (United States)

    Hosoya, Yumiko; Shiraishi, Takanobu; Odatsu, Tetsuro; Nagafuji, Junichi; Kotaku, Mayumi; Miyazaki, Masashi; Powers, John M

    2011-09-01

    This study evaluated the effects of polishing on surface roughness, gloss, and color of regular, opaque, and enamel shades for each of three resin composites. Two-mm-thick resin disks made with Estelite Σ Quick, Clearfil Majesty, and Beautifil II were final polished with 180-, 1000-, and 3000-grit silicon carbide paper. Surface roughness, gloss, and color were measured one week after curing. Estelite Σ Quick had significantly lower roughness values and significantly higher gloss values as compared with Clearfil Majesty and Beautifil II. The effects of surface roughness and gloss on color (L*a*b*) differed among resin composites and by shade. Correlation coefficients between surface roughness and L*a*b* color factors were generally high for Clearfil Majesty, partially high (i.e., between roughness and L*) for Beautifil II, and low for Estelite Σ Quick. Correlation coefficients between gloss and L*a*b* color parameters were generally high for Beautifil II and low for Estelite Σ Quick and Clearfil Majesty. However, for all resin composites, the values of the color differences between 3000-grit and 180-grit polishing groups for all shades were imperceptible by the naked eye.

  4. Effect of Pre-heating on Microtensile Bond Strength of Composite Resin to Dentin.

    Directory of Open Access Journals (Sweden)

    Abdolrahim Davari

    2014-10-01

    Full Text Available Direct composite resin restorations are widely used and the impact of different storage temperatures on composites is not well understood. The purpose of this study was to evaluate the microtensile bond strength of composite to dentin after different pre-curing temperatures.Occlusal surfaces of 44 human molars were ground with diamond burs under water coolant and polished with 600 grit silicon carbide papers to obtain flat dentin surfaces. The dentin was etched with 37% phosphoric acid and bonded with Adper Single Bond 2 according to the manufacturer's instructions. The specimens were randomly divided into two groups (n=22 according to the composite resin applied: FiltekP60 and Filtek Z250. Each group included three subgroups of composite resin pre-curing temperatures (4°C, 23°C and 37°C. Composite resins were applied to the dentin surfaces in a plastic mold (8mm in diameter and 4mm in length incrementally and cured. Twenty-two composite-to-dentin hour-glass sticks with one mm(2 cross-sectional area per group were prepared. Microtensile bond strength measurements were made using a universal testing machine at a crosshead speed of one mm/min. For statistical analysis, t-test, one-way and two-way ANOVA were used. The level of significance was set at P<0.05.Filtek P60 pre-heated at 37ºC had significantly higher microtensile bond strength than Filtek Z250 under the same condition. The microtensile bond strengths were not significantly different at 4ºC, 23ºC and 37ºC subgroups of each composite resin group.Filtek P60 and Filtek Z250 did not have significantly different microtensile bond strengths at 4ºC and 23ºC but Filtek P60 had significantly higher microtensile bond strength at 37 ºC. Composite and temperature interactions had significant effects on the bond strength.

  5. Accelerated aging of adhesive-mediated fiber post-resin composite bonds: A modeling approach.

    Science.gov (United States)

    Radovic, Ivana; Monticelli, Francesca; Papacchini, Federica; Magni, Elisa; Cury, Alvaro Hafiz; Vulicevic, Zoran R; Ferrari, Marco

    2007-08-01

    Although fiber posts luted in root canals are not directly exposed to oral fluids, water storage is considered as in vitro accelerated aging test for bonded interfaces. The aim of the study was to evaluate the influence of accelerated water aging on fiber post-resin composite adhesion. Forty fiber posts (DT Light Post, RTD) were randomly divided into two main groups, according to the surface treatment performed. Group I: XPBond adhesive (Dentsply Caulk); Group II: sandblasting (Rocatec-Pre, 3M ESPE) and XPBond. Dual-cured resin cement (Calibra, Dentsply Caulk) and flowable composite (X-Flow, Dentsply Caulk) were applied on the posts to produce cylindrical specimens. The bond strength at the interface between post and cement/composite was measured with the microtensile test according to the non-trimming technique. Half of the sticks were tested immediately for bond strength, while in the other half testing was performed after 1 month of water storage at 37 degrees C. Post-cement/composite interfaces were evaluated under SEM prior and after water aging. Statistical analysis was performed using the Kruskal-Wallis ANOVA followed by Dunn's multiple range test (p<0.05). Immediate bond strength was higher on sandblasted posts. After water aging the two post surface treatments resulted comparable in bond strength. Resin cement achieved higher bond strength to fiber posts than flowable composite. Water aging significantly reduced bond strength. Sandblasting followed by adhesive coating may improve immediate post-resin bond strength in comparison to adhesive alone. However, fiber post-resin bond strength mediated by hydrophilic adhesive tends to decrease after water aging.

  6. Ceramic matrix and resin matrix composites - A comparison

    Science.gov (United States)

    Hurwitz, Frances I.

    1987-01-01

    The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.

  7. Ceramic matrix and resin matrix composites: A comparison

    Science.gov (United States)

    Hurwitz, Frances I.

    1987-01-01

    The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.

  8. The effect of proximal contour on marginal ridge fracture of Class II composite resin restorations.

    NARCIS (Netherlands)

    Loomans, B.A.C.; Roeters, F.J.M.; Opdam, N.J.M.; Kuijs, R.H.

    2008-01-01

    OBJECTIVES: To compare the marginal ridge fracture strength of Class II composite resin restorations placed with a straight or contoured matrix band using composite resins with different modulus of elasticity. METHODS: In 60 artificial first molars standardized MO-preparations were ground. Two

  9. Radiopacity of Methacrylate and Silorane Composite Resins Using a Digital Radiographic System.

    Science.gov (United States)

    Firoozmand, Leily Macedo; Cordeiro, Mariana Gonçalves; Da Silva, Marcos André Dos Santos; De Jesus Tavarez, Rudys Rodolfo; Matos Maia Filho, Etevaldo

    The aim of this study was to evaluate the radiopacity of silorane and methacrylate resin composites, comparing them to the enamel, dentin, and aluminum penetrometer using a digital image. From six resin composites (Filtek ™ P90, Filtek Z350, Filtek Z350 XT flow, Tetric Ceram, TPH Spectrum, and SureFil SDR flow) cylindrical disks (5 × 1 mm) were made and radiographed by a digital method, together with a 15-step aluminum step-wedge and a 1 mm slice of human tooth. The degree of radiopacity of each image was quantified using digital image processing. The mean values of the shades of gray of the tested materials were measured and the equivalent width of aluminum was calculated for each resin. The results of our work yielded the following radiopacity values, given here in descending order: Tetric Ceram > TPH > SDR > Z350 > Z350 flow > P90 > enamel > dentin. The radiopacity of the materials was different both for the enamel and for the dentin, except for resin P90, which was no different than enamel. In conclusion, silorane-based resin exhibited a radiopacity higher than dentin and closest to the enamel; a large portion of the methacrylate-based flow and conventional resins demonstrated greater radiopacity in comparison to dentin and enamel.

  10. Effect of organic solvents compared to sandblasting on the repair bond strength of nanohybrid and nanofilled composite resins

    Directory of Open Access Journals (Sweden)

    Rafael Torres Brum

    2017-01-01

    Full Text Available Background: This study evaluated the effect of different surface treatments on the repair bond strength of nanohybrid (Empress Direct and nanofilled (Filtek Z350 XT composite resins. Materials and Methods: A total of 120 specimens of each material (7.5 x 4.5 x 3 mm were prepared and polished with SiC paper. Half of the specimens were kept in water for seven days and the other half for six months; they were then divided into six groups according to the type of surface treatment: negative control (no treatment, Al2O3sandblasted, liquid acetone, acetone gel, liquid alcohol and alcohol gel. Following application of the silane coupling agent and the adhesive system, composite resin cylinders were fabricated on the specimens and light cured (20 seconds. The same composite resins were used for the repair. Additionally, ten intact specimens of each composite resin (without repair were prepared (positive control. The specimens were then loaded to failure in the microshear mode. Three additional specimens were fabricated in each group, and the surface treatments were analyzed by atomic force microscopy, energy-dispersive X-ray spectroscopy (EDS and scanning electron microscopy (SEM. Results: The nanofilled composite resin showed higher cohesive strength and repair bond strength than the nanohybrid composite resin. The aging process affected the repair bond strength of the nanofilled composite resin. Al2O3sandblasting was more efficient for the nanofilled composite resin and promoted greater surface roughness in both materials. The solvents demonstrated higher efficacy for the nanohybrid composite resin. Conclusion: The strengths resulting from the solvents were material dependent, and Al2O3sandblasting resulted in superior repair bond strength in both materials.

  11. Effect of light dispersion of LED curing lights on resin composite polymerization.

    Science.gov (United States)

    Vandewalle, Kraig S; Roberts, Howard W; Andrus, Jeffrey L; Dunn, William J

    2005-01-01

    This study evaluated the effect of light dispersion of halogen and LED curing lights on resin composite polymerization. One halogen (Optilux 501, SDS/Kerr, Orange, CA, USA) and five light-emitting diode (LED) curing lights (SmartLite iQ, Dentsply Caulk, Milford, DE, USA; LEDemetron 1, SDS/Kerr; FLASHlite 1001, Discus Dental, Culver City, CA, USA; UltraLume LED 5, Ultradent Products, South Jordan, UT, USA; Allegro, Den-Mat, Santa Maria, CA, USA) were used in this study. Specimens (8 mm diameter by 2 mm thick) were made in polytetrafluoroethylene molds using hybrid (Z100, 3M ESPE, St. Paul, MN, USA) and microfill (A110, 3M ESPE) composite resins. The top surface was polymerized for 5 seconds with the curing light guide tip positioned at a distance of 1 and 5 mm. Degree of conversion (DC) of the composite specimens was analyzed on the bottom surface using micro-Fourier Transform Infrared (FTIR) spectroscopy (Perkin-Elmer FTIR Spectrometer, Wellesley, PA, USA) 10 minutes after light activation. DC at the bottom of the 2 mm specimen was expressed as a percentage of the mean maximum DC. Five specimens were created per curing light and composite type (n=5). Percent mean DC ratios and SDs were calculated for each light under each testing condition. Data were analyzed by analysis of variance (ANOVA)/Tukey's test (alpha = .05). A beam analyzer (LBA-700, Spiricon, Logan, UT, USA) was used to record the emitted light from the curing lights at 0 and 5 mm distances (n=5). A Top Hat factor was used to compare the quality of the emitted beam profile (LBA/PC, Spiricon). The divergence angle from vertical was also determined in the x- and y-axes (LBA/PC). Mean values and SDs were calculated for each light under each testing condition (0 and 5 mm, x- and y-axes) and analyzed by a two-way ANOVA/Tukey's test (alpha = .05). For DC ratios, significant differences were found based on curing light and curing distance (p < .05). At 1 mm, Optilux 501 and FLASHlite 1001 produced significantly

  12. Comparison of Shear Bond Strength of RMGI and Composite Resin for Orthodontic Bracket Bonding

    Science.gov (United States)

    Yassaei, Soghra; Davari, Abdolrahim; Goldani Moghadam, Mahjobeh; Kamaei, Ahmad

    2014-01-01

    Objective: The aim of this study was to compare the shear bond strength (SBS) of resin modified glass ionomer (RMGI) and composite resin for bonding metal and ceramic brackets. Materials and Methods: Eighty-eight human premolars extracted for orthodontic purposes were divided into 4 groups (n=22). In groups 1 and 2, 22 metal and ceramic brackets were bonded using composite resin (Transbond XT), respectively. Twenty-two metal and ceramic brackets in groups 3 and 4, respectively were bonded using RMGI (Fuji Ortho LC, Japan). After photo polymerization, the teeth were stored in water and thermocycled (500 cycles between 5° and 55°). The SBS value of each sample was determined using a Universal Testing Machine. The amount of residual adhesive remaining on each tooth was evaluated under a stereomicroscope. Statistical analyses were done using two-way ANOVA. Results: RMGI bonded brackets had significantly lower SBS value compared to composite resin bonded groups. No statistically significant difference was observed between metal and ceramic brackets bonded with either the RMGI or composite resin. The comparison of the adhesive remnant index (ARI) scores between the groups indicated that the bracket failure mode was significantly different among groups (Porthodontic bonding purposes; however the provided SBS is still within the clinically acceptable range. PMID:25628663

  13. Ultrasonic Characterisation of Epoxy Resin/Polyethylene Terephthalate (PET Char Powder Composites

    Directory of Open Access Journals (Sweden)

    Imran ORAL

    2016-11-01

    Full Text Available This study is carried out in order to determine the elastic properties of the Epoxy Resin (ER / Polyethylene terephthalate (PET Char Powder Composites by ultrasonic wave velocity measurement method. Plastic waste was recycled as raw material for the preparation of epoxy composite materials. The supplied chars were mixed with epoxy resin matrix at weight percentages of 10 %, 20 % and 30 % for preparing ER/PET Char Powder (PCP composites. The effect of PET char powder on the elastic properties of ER/PCP composites were investigated by ultrasonic pulse-echo method. According to the obtained results, the composition ratio of 80:20 is the most appropriate composition ratio, which gave the highest elastic constants values for ER/PCP composites. On the other hand, the best electrical conductivity value was obtained for 70:30 composition ratio. It was observed that ultrasonic shear wave velocity correlated more perfectly than any other parameters with hardness.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12190

  14. Repair of Defective Composite Resin Restoration: Current Trend ...

    African Journals Online (AJOL)

    Background: Repair of defective composite resins restorations is being increasingly recognized as a viable alternative to replacement. there is however no consensus yet on the treatment protocol. Objective: To determine the views and practice of specialists in Conservative Dentistry in Nigeria as regard to repair procedure ...

  15. Longevity of posterior resin composite restorations in permanent teeth in Public Dental Health Service

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan W V; Halken, Jette

    2013-01-01

    To investigate in a prospective follow up the longevity of posterior resin composites (RC) placed in permanent teeth of children and adolescents attending Public Dental Health Service.......To investigate in a prospective follow up the longevity of posterior resin composites (RC) placed in permanent teeth of children and adolescents attending Public Dental Health Service....

  16. Damage analysis of fiber reinforced resin matrix composites irradiated by CW laser

    International Nuclear Information System (INIS)

    Wan Hong; Hu Kaiwei; Mu Jingyang; Bai Shuxin

    2008-01-01

    In this paper, the damage modes of the carbon fiber and the glass fiber reinforced epoxy or bakelite resin matrix composites irradiated by CW laser under different power densities were analyzed, and the changes of the microstructure and the tensile strength of the composites were also researched. When the resin matrix composites were radiated at a power density more than 0.1 kW/cm 2 , the matrix would be decomposed and the tensile properties of the radiated samples were lost over 30% while the carbon fiber hardly damaged and the glass fiber melted. When the power density of the laser was raised to 1 kW/cm 2 , the matrix burned violently and the carbon fiber cloth began to split with some carbon fiber being fractured, therefore, the fracture strength of the radiated sample lost over 80%. The higher the power density of radiation was, the more serious the damage of the sample was. It was also found that the difference of the matrixes had little effect on the damage extent of the composites. The influence of the radiation density on the temperature of the radiated surface of the carbon/resin composite was numerically calculated by ANSYS finite element software and the calculation results coincided with the damage mode of the radiated composites. (authors)

  17. Translucency and masking ability of various composite resins at different thicknesses.

    Science.gov (United States)

    Darabi, Farideh; Radafshar, Golpar; Tavangar, Maryam; Davaloo, Reza; Khosravian, Aref; Mirfarhadi, Nastaran

    2014-09-01

    Optical properties of the composite resins, concerning their translucency and thickness, are affected by discolored tooth structure or inherent darkness of the oral cavity. This study aimed to compare the translucency parameter (TP) of five different composite resins in different thicknesses and to evaluate their masking ability in black backgrounds. Five brands of composite resins; Gradia (GC) and Crystalline (Confi-dental) in opaque A2 (OA2), Vit-l-escence (Ultradent) in opaque snow (OS), Herculite XRV (Kerr) and Opallis (FGM) in dentin A2 (DA2) shades were selected to enroll the study. Color coordinates of each composite were determined at 0.5, 1, and 1.5 mm thicknesses on a white backing, the backing of material itself and a black backing were calculated by using a spectrophotometer to evaluate the translucency parameter (TP) of the study materials. The masking ability was also calculated from the specimens on the material itself and on black backing. The values under 2 were estimated as imperceptible. One-way ANOVA, T-test and Tukey HSD were employed for statistical analysis. The masking ability values, recorded for the 1.5 mm-thick specimens, were in the range of imperceptible except for the Herculite. There was no difference in TP values of the materials at 1.5 mm thickness. Opaque snow shade of Vit-l-escence and opaque A2 shade of Gradia showed lower TP values in comparison with the other 1 and 0.5 mm-thick materials and this difference was statistically significant (pcomposite resins could not mask the black background color.

  18. Comparison of time-dependent changes in the surface hardness of different composite resins

    Science.gov (United States)

    Ozcan, Suat; Yikilgan, Ihsan; Uctasli, Mine Betul; Bala, Oya; Kurklu, Zeliha Gonca Bek

    2013-01-01

    Objective: The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior). Materials and Methods: From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bottom surface hardness of these samples was measured using a Vicker's hardness tester. The samples were then stored at 37°C and 100% humidity. After 24 h and 7, 30 and 90 days, the top and bottom surface hardness of the samples was measured. In each measurement, the rate between the hardness of the top and bottom surfaces were recorded as the hardness rate. Statistical analysis was performed by one-way analysis of variance, multiple comparisons by Tukey's test and binary comparisons by t-test with a significance level of P = 0.05. Results: The highest hardness values were obtained from each two surfaces of Majesty Posterior and the lowest from Filtek Silorane. Both the top and bottom surface hardness of the methacrylate based composite resins was high and there was a statistically significant difference between the top and bottom hardness values of only the silorane-based composite, Filtek Silorane (P composite resin Filtek Silorane showed adequate hardness ratio, the use of incremental technic during application is more important than methacrylate based composites. PMID:24966724

  19. Reduced toxicity polyester resins and microvascular pre-preg tapes for advanced composites manufacturing

    Science.gov (United States)

    Poillucci, Richard

    Advanced composites manufacturing broadly encapsulates topics ranging from matrix chemistries to automated machines that lay-up fiber-reinforced materials. Environmental regulations are stimulating research to reduce matrix resin formulation toxicity. At present, composites fabricated with polyester resins expose workers to the risk of contact with and inhalation of styrene monomer, which is a potential carcinogen, neurotoxin, and respiratory irritant. The first primary goal of this thesis is to reduce the toxicity associated with polyester resins by: (1) identification of potential monomers to replace styrene, (2) determination of monomer solubility within the polyester, and (3) investigation of approaches to rapidly screen a large resin composition parameter space. Monomers are identified based on their ability to react with polyester and their toxicity as determined by the Globally Harmonized System (GHS) and a green screen method. Solubilities were determined by the Hoftyzer -- Van Krevelen method, Hansen solubility parameter database, and experimental mixing of monomers. A combinatorial microfluidic mixing device is designed and tested to obtain distinct resin compositions from two input chemistries. The push for safer materials is complemented by a thrust for multifunctional composites. The second primary goal of this thesis is to design and implement the manufacture of sacrificial fiber materials suitable for use in automated fiber placement of microvascaular multifunctional composites. Two key advancements are required to achieve this goal: (1) development of a roll-to-roll method to place sacrificial fibers onto carbon fiber pre-preg tape; and (2) demonstration of feasible manufacture of microvascular carbon fiber plates with automated fiber placement. An automated method for placing sacrificial fibers onto carbon fiber tapes is designed and a prototype implemented. Carbon fiber tows with manual placement of sacrificial fibers is implemented within an

  20. Modeling the curing process of thermosetting resin matrix composites

    Science.gov (United States)

    Loos, A. C.

    1986-01-01

    A model is presented for simulating the curing process of a thermosetting resin matrix composite. The model relates the cure temperature, the cure pressure, and the properties of the prepreg to the thermal, chemical, and rheological processes occurring in the composite during cure. The results calculated with the computer code developed on the basis of the model were compared with the experimental data obtained from autoclave-curved composite laminates. Good agreement between the two sets of results was obtained.

  1. Influence of salivary enzymes and alkaline pH environment on fatigue behavior of resin composites

    NARCIS (Netherlands)

    Mirmohammadi, H.; Kleverlaan, C.J.; Aboushelib, M.N.; Feilzer, A.J.

    2011-01-01

    Purpose: To evaluate the effect of enzymatic activity and alkaline medium on flexural strength and rotary fatigue resistance of direct and indirect resin composite restorative materials. Methods: Three direct resin composite materials Filtek Z100, Filtek Z250 and Filtek Silorane (3M ESPE), and two

  2. Creep deformation of restorative resin-composites intended for bulk-fill placement.

    Science.gov (United States)

    El-Safty, S; Silikas, N; Watts, D C

    2012-08-01

    To determine the creep deformation of several "bulk-fill" resin-composite formulations in comparison with some other types. Six resin-composites; four bulk-fill and two conventional were investigated. Stainless steel split molds (4 mm × 6 mm) were used to prepare cylindrical specimens for creep testing. Specimens were thoroughly irradiated with 650 mW cm(-2). A total of 10 specimens for each material were divided into two groups (n = 5) according to the storage condition; Group A stored dry at 37 °C for 24h and Group B stored in distilled water at 37 °C in an incubator for 24h. Each specimen was loaded (20 MPa) for 2h and unloaded for 2h. The strain deformation was recorded continuously for 4h. Statistical analysis was performed using a two-way ANOVA followed by one-way ANOVA and the Bonferroni post hoc test at a significance level of a = 0.05. The maximum creep strain % ranged from 0.72% up to 1.55% for Group A and the range for Group B increased from 0.79% up to 1.80% due to water sorption. Also, the permanent set ranged from 0.14% up to 0.47% for Group A and from 0.20% up to 0.59% for Group B. Dependent on the material and storage condition, the percentage of creep strain recovery ranged between 64% and 81%. Increased filler loading in the bulk-fill materials decreased the creep strain magnitude. Creep deformation of all studied resin-composites increased with wet storage. The "bulk-fill" composites exhibited an acceptable creep deformation and within the range exhibited by other resin-composites. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  3. CHEMICAL COMPOSITIONS OF PINE RESIN, ROSIN AND TURPENTINE OIL FROM WEST JAVA

    OpenAIRE

    Wiyono Bambang; Tachibana Sanro; Djaban Tinambunan

    2006-01-01

    This study was conducted to identify chemical composition of merkus pine resin, rosin and turpentine oil. Initially, pine resin was separated into neutral and acidic fractions with an aqueous 4% sodium hydroxide solution. After methylation, the fraction containing turpentine oil and rosin were analyzed by gas chromatography (GC), and gas chromatograph mass spectrometry (GC-MS), respectively. The neutral fraction of pine resin and turpentine oil mainly consisted of a-pinene, D-3-carene and b-p...

  4. EFFECT OF SURFACE SEALING ON STAIN RESISTANCE OF A NANO-HYBRID RESIN COMPOSITE*

    Directory of Open Access Journals (Sweden)

    Günçe SAYGI

    2015-04-01

    Full Text Available Purpose: This study investigated the influence of sealant application on stain resistance of a nanohybrid resin composite compared to the efficacy of a bonding agent used as a surface sealant on prolonging color stability of the resin composite. Materials and Methods: 28 disc-shaped materials were prepared from a nano-hybrid resin composite Filtek Z550 and assigned to four groups: G1K: nonsealed; G2:Adper Single Bond; G3: Fortify ; G4: Biscover LV. After 24 h storage in distilled water at 37˚C, all specimens were subjected to thermocycling and immersed into coffee solution. Color measurements were performed using spectrophotometer (VITA Easyshade; Vident according to CIEL*a*b* system. Results: Color change values were significantly different among the groups in each evaluation period except for after thermocycling (p<0.05. For 7 days evaluation period, the difference between G3 and G4 group was statistically significant while G4 exhibited statistically significant differences (p<0.05 and p<0.0001 respectively compared to control (G1 in 14 day whereas no significant difference was found between GI and GII in 28-day evaluation period. However, ΔE values of sealed specimens (GIII, GIV differed significantly from non-sealed (GI specimens after 28 days of immersion in coffee solution (p<0.05 and p<0.0001 respectively. Conclusion: It may be concluded that using a bonding agent as a surface sealant does not increase stain resistance of resin composites of the sealants evaluated. Biscover LV showed the highest efficacy to prolong color stability of the resin composite.

  5. Effect of LED and Argon Laser on Degree of Conversion and Temperature Rise of Hybrid and Low Shrinkage Composite Resins.

    Science.gov (United States)

    Pahlevan, Ayob; Tabatabaei, Masumeh Hasani; Arami, Sakineh; Valizadeh, Sara

    2016-01-01

    Different light curing units are used for polymerization of composite resins. The aim of this study was to evaluate the degree of conversion (DC) and temperature rise in hybrid and low shrinkage composite resins cured by LED and Argon Laser curing lights. DC was measured using FTIR spectroscopy. For measuring temperature rise, composite resin samples were placed in Teflon molds and cured from the top. The thermocouple under samples recorded the temperature rise. After initial radiation and specimens reaching the ambient temperature, reirradiation was done and temperature was recorded again. Both temperature rise and DC data submitted to one-way ANOVA and Tukey-HSD tests (5% significance). The obtained results revealed that DC was not significantly different between the understudy composite resins or curing units. Low shrinkage composite resin showed a significantly higher temperature rise than hybrid composite resin. Argon laser caused the lowest temperature rise among the curing units. Energy density of light curing units was correlated with the DC. Type of composite resin and light curing unit had a significant effect on temperature rise due to polymerization and curing unit, respectively.

  6. Correlating cytotoxicity to elution behaviors of composite resins in term of curing kinetic.

    Science.gov (United States)

    Meng, Junquan; Yang, Huichuan; Cao, Man; Li, Lei; Cai, Qing

    2017-09-01

    Cytotoxicity of photocurable composite resins is a key issue for their safe use in dental restoration. Curing kinetic and elution behaviors of the composite resin would have decisive effects on its cytotoxicity. In this study, composite resins composed of bisphenol-glycidyl dimethacrylate (Bis-GMA), triethyleneglycol dimethacrylate (TEGDMA), camphorquinone (CQ), N,N-dimethylaminoethyl methacrylate (DMAEMA) and barium glass powders were prepared by setting the photoinitiators CQ/DMAEMA at 0.5wt%, 1wt% or 3wt% of the total weight of Bis-GMA/TEGDMA. The ratio of Bis-GMA/TEGDMA was 6:4, the ratio of CQ/DMAEMA was 1:1, and the incorporated inorganic powder was 75wt%. Then, curing kinetics were studied by using real-time Fourier transform infrared spectroscopy (FTIR) and photo-DSC (differential scanning calorimeter). Elution behaviors in both ethanol solution and deionized water were monitored by using liquid chromatogram/mass spectrometry (LC/MS). Cytotoxicity was evaluated by in vitro culture of L929 fibroblasts. Finally, they were all analyzed and correlated in terms of initiator contents. It was found that the commonly used 0.5wt% of photoinitiators was somewhat insufficient in obtaining composite resin with low cytotoxicity. Copyright © 2017. Published by Elsevier B.V.

  7. Effect of fiber inserts on gingival margin microleakage of Class II bulk-fill composite resin restorations.

    Science.gov (United States)

    Shafiei, Fereshteh; Doozandeh, Maryam; Karimi, Vahid

    2018-01-01

    This study evaluated the effect of fiber inserts combined with composite resins on enamel and dentin margin microleakage. The fiber inserts were used with high- (x-tra fil) and low-viscosity (x-tra base) bulk-fill composite resins and as well as conventional composite resins (Grandio and Grandio Flow). In 96 sound, recently extracted molars, 2 standardized Class II cavities were prepared. The teeth were randomly divided into 8 groups of 12 teeth each, based on composite resin type and presence or absence of fiber inserts: groups 1 and 2, x-tra fil with and without fiber inserts, respectively; groups 3 and 4, x-tra base with and without fiber inserts; groups 5 and 6, Grandio with and without fiber inserts; and groups 7 and 8, Grandio Flow liner (gingival floor)/Grandio (remainder of cavity) with and without fiber inserts. In all the groups, a 2-step etch-and-rinse adhesive was used. The specimens were processed in a dye penetration technique to determine microleakage percentages. Data were analyzed with analysis of variance, Tukey, and t tests. There was significantly less leakage at the enamel margins than the dentin margins. Fiber reinforcement significantly decreased enamel microleakage in all the groups, with no significant differences among the groups. Concerning dentin microleakage, there were no significant differences among the 4 groups without fiber inserts, while a significant difference was detected in groups 2 (x-tra fil plus fiber) and 8 (Grandio Flow plus fiber/Grandio). Fibers significantly improved dentin sealing in groups 2 and 8. These findings suggest that a fiber insert reinforcing bulk-fill and conventional composite resins might improve enamel sealing in shallow Class II cavi-ties. The effect of fiber reinforcement on the dentin margins of deep cavities depended on the viscosity of the composite resins; fiber reinforcement was effective for flowable bulk-fill and conventional composite resin restorations.

  8. Influence of surface roughness on streptococcal adhesion forces to composite resins

    NARCIS (Netherlands)

    Mei, Li; Busscher, Henk J; van der Mei, Henny C; Ren, Yijin

    OBJECTIVE: To determine streptococcal adhesion forces with composite resins with different surface roughness. METHODS: Polishing and grinding were applied to obtain smooth (roughness 20 nm), moderately rough (150 nm) and rough (350 nm) surfaces of two orthodontic, light-cured composites. Adhesion

  9. Effect of curing mode on the hardness of dual-cured composite resin core build-up materials

    Directory of Open Access Journals (Sweden)

    César Augusto Galvão Arrais

    2010-06-01

    Full Text Available This study evaluated the Knoop Hardness (KHN values of two dual-cured composite resin core build-up materials and one resin cement exposed to different curing conditions. Two dual-cured core build-up composite resins (LuxaCore®-Dual, DMG; and FluoroCore®2, Dentsply Caulk, and one dual-cured resin cement (Rely X ARC, 3M ESPE were used in the present study. The composite materials were placed into a cylindrical matrix (2 mm in height and 3 mm in diameter, and the specimens thus produced were either light-activated for 40 s (Optilux 501, Demetron Kerr or were allowed to self-cure for 10 min in the dark (n = 5. All specimens were then stored in humidity at 37°C for 24 h in the dark and were subjected to KHN analysis. The results were submitted to 2-way ANOVA and Tukey's post-hoc test at a pre-set alpha of 5%. All the light-activated groups exhibited higher KHN values than the self-cured ones (p = 0.00001, regardless of product. Among the self-cured groups, both composite resin core build-up materials showed higher KHN values than the dual-cured resin cement (p = 0.00001. LuxaCore®-Dual exhibited higher KHN values than FluoroCore®2 (p = 0.00001 when they were allowed to self-cure, while no significant differences in KHN values were observed among the light-activated products. The results suggest that dual-cured composite resin core build-up materials may be more reliable than dual-cured resin cements when curing light is not available.

  10. Evaluation of Polymerization Efficacy in Composite Resins via FT-IR Spectroscopy and Vickers Microhardness Test

    Directory of Open Access Journals (Sweden)

    Tahereh-Sadat Jafarzadeh

    2015-12-01

    Full Text Available Background and aims. Polymerization efficacy affects the properties and performance of composite resin restorations.The purpose of this study was to evaluate the effectiveness of polymerization of two micro-hybrid, two nano-hybrid and one nano-filled ormocer-based composite resins, cured by two different light-curing systems, using Fourier transformation infrared (FT-IR spectroscopy and Vickers microhardness testing at two different depths (top surface, 2 mm. Materials and methods. For FT-IR spectrometry, five cylindrical specimens (5mm in diameter × 2 mm in length were prepared from each composite resin using Teflon molds and polymerized for 20 seconds. Then, 70-μm wafers were sectioned at the top surface and at2mm from the top surface. The degree of conversion for each sample was calculated using FT-IR spectroscopy. For Vickers micro-hardness testing, three cylindrical specimens were prepared from each composite resin and polymerized for 20 seconds. The Vickers microhardness test (Shimadzu, Type M, Japan was performed at the top and bottom (depth=2 mm surfaces of each specimen. Three-way ANOVA with independent variables and Tukey tests were performed at 95% significance level. Results. No significant differences were detected in degree of conversion and microhardness between LED and QTH light-curing units except for the ormocer-based specimen, CeramX, which exhibited significantly higher DC by LED. All the composite resins showed a significantly higher degree of conversion at the surface. Microhardness was not significantly affected by depth, except for Herculite XRV Ultra and CeramX, which showed higher values at the surface. Conclusion. Composite resins containing nano-particles generally exhibited more variations in degree of conversion and microhardness.

  11. Evaluation of Polymerization Efficacy in Composite Resins via FT-IR Spectroscopy and Vickers Microhardness Test.

    Science.gov (United States)

    Jafarzadeh, Tahereh-Sadat; Erfan, Mohammad; Behroozibakhsh, Marjan; Fatemi, Mostafa; Masaeli, Reza; Rezaei, Yashar; Bagheri, Hossein; Erfan, Yasaman

    2015-01-01

    Background and aims. Polymerization efficacy affects the properties and performance of composite resin restorations.The purpose of this study was to evaluate the effectiveness of polymerization of two micro-hybrid, two nano-hybrid and one nano-filled ormocer-based composite resins, cured by two different light-curing systems, using Fourier transformation infrared (FT-IR) spectroscopy and Vickers microhardness testing at two different depths (top surface, 2 mm). Materials and methods. For FT-IR spectrometry, five cylindrical specimens (5mm in diameter × 2 mm in length) were prepared from each composite resin using Teflon molds and polymerized for 20 seconds. Then, 70-μm wafers were sectioned at the top surface and at2mm from the top surface. The degree of conversion for each sample was calculated using FT-IR spectroscopy. For Vickers micro-hardness testing, three cylindrical specimens were prepared from each composite resin and polymerized for 20 seconds. The Vickers microhardness test (Shimadzu, Type M, Japan) was performed at the top and bottom (depth=2 mm) surfaces of each specimen. Three-way ANOVA with independent variables and Tukey tests were performed at 95% significance level. Results. No significant differences were detected in degree of conversion and microhardness between LED and QTH light-curing units except for the ormocer-based specimen, CeramX, which exhibited significantly higher DC by LED. All the composite resins showed a significantly higher degree of conversion at the surface. Microhardness was not significantly affected by depth, except for Herculite XRV Ultra and CeramX, which showed higher values at the surface. Conclusion. Composite resins containing nano-particles generally exhibited more variations in degree of conversion and microhardness.

  12. Distance and protective barrier effects on the composite resin degree of conversion

    Science.gov (United States)

    Coutinho, Margareth; Trevizam, Natália Carvalho; Takayassu, Renata Nakase; Leme, Ariene Arcas; Soares, Giulliana Panfiglio

    2013-01-01

    Context: The food wrap films are used to cover the tip of curing light units in order to avoid contamination and prevent damage to the light guide. However, their effects on resin polymerization are not fully known. Aims: We investigated the effects on restoration efficiency of a food wrap protective barrier used on the tip of curing light units. Materials and Methods: For each treatment, five replications were performed, a total of 60 bovine incisor. The degree of conversion (%DC) of restorations with the composite resin Opallis EA2 was evaluated using 3 curing light devices (Optilux 501, Optilight and Ultra LED) and 2 curing distances (0 and 5 mm). The composite resin was tested for restoration of cavities in bovine crowns. %DC values were measured by the Fourier transform infrared spectroscopy-attenuated total reflectance technique. Statistical Analysis Used: The data were analyzed using 3-way ANOVA and Tukey's test. Results: Use of the protective film lowered %DC (F = 4.13; P = 0.05), and the effects of curing distance were associated to the curing light device (F = 3.61; P = 0.03). Conclusions: The distance from the light curing tip and use of a translucent protective barrier on the light-cure device can both impair composite resin %DC. PMID:24015001

  13. Boron/aluminum graphite/resin advanced fiber composite hybrids

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F.; Sullivan, T. L.

    1975-01-01

    Fabrication feasibility and potential of an adhesively bonded metal and resin matrix fiber-composite hybrid are determined as an advanced material for aerospace and other structural applications. The results show that using this hybrid concept makes possible a composite design which, when compared with nonhybrid composites, has greater transverse strength, transverse stiffness, and impact resistance with only a small penalty on density and longitudinal properties. The results also show that laminate theory is suitable for predicting the structural response of such hybrids. The sequence of fracture modes indicates that these types of hybrids can be readily designed to meet fail-safe requirements.

  14. Radiopacity of Methacrylate and Silorane Composite Resins Using a Digital Radiographic System

    Directory of Open Access Journals (Sweden)

    Leily Macedo Firoozmand

    2016-01-01

    Full Text Available The aim of this study was to evaluate the radiopacity of silorane and methacrylate resin composites, comparing them to the enamel, dentin, and aluminum penetrometer using a digital image. From six resin composites (Filtek™ P90, Filtek Z350, Filtek Z350 XT flow, Tetric Ceram, TPH Spectrum, and SureFil SDR flow cylindrical disks (5 × 1 mm were made and radiographed by a digital method, together with a 15-step aluminum step-wedge and a 1 mm slice of human tooth. The degree of radiopacity of each image was quantified using digital image processing. The mean values of the shades of gray of the tested materials were measured and the equivalent width of aluminum was calculated for each resin. The results of our work yielded the following radiopacity values, given here in descending order: Tetric Ceram > TPH > SDR > Z350 > Z350 flow > P90 > enamel > dentin. The radiopacity of the materials was different both for the enamel and for the dentin, except for resin P90, which was no different than enamel. In conclusion, silorane-based resin exhibited a radiopacity higher than dentin and closest to the enamel; a large portion of the methacrylate-based flow and conventional resins demonstrated greater radiopacity in comparison to dentin and enamel.

  15. Mechanical and Magnetic Properties of YBCO Superconductor with Bi/CNT Composite and Resin/CNT Impregnation

    International Nuclear Information System (INIS)

    Oh, W. S.; Jang, G. E.; Han, Y. H.; Sung, T. H.

    2007-01-01

    Bi/CNT composite and resin/CNT were chosen to improve the mechanical properties of YBa 2 Cu 3 O 7 (YBCO) superconductor. In order to elucidate the effects of Bi/CNT composite and resin/CNT in YBCO superconductors, melt texture superconductor were impregnated by mixed compound of Bi and CNT into the artificial holes parallel to the c-axis, which were drilled on the YBCO superconductor. Various amount of Bi/CNT and resin/CNT were impregnated to YBCO superconductor with different holes diameters. Typical artificial holes diameters were 0.5, 0.7, and 1.0 mm respectively. Result of three-point bending test measurement, the bending strength with resin/CNT impregnation was improved up to 59.64 MPa as compared with 50.79 MPa of resin/CNT free bulk. Resin/CNT impregnation has been found to be one of the effective ways in improving the mechanical properties of bulk superconductor.

  16. The Influence of Hydroxylated Carbon Nanotubes on Epoxy Resin Composites

    Directory of Open Access Journals (Sweden)

    Jiaoxia Zhang

    2012-01-01

    Full Text Available Hydroxylated multiwall carbon nanotubes (MWNTs/epoxy resin nanocomposites were prepared with ultrasonic dispersion and casting molding. The effect of hydroxylated MWNTs content on reactive activity of composites is discussed. Then the flexural and electrical properties were studied. Transmission electron microscope was employed to characterize the microstructure of nanocomposites. As a result, the reactive activity of nanocomposites obtained increases with the increasing content of MWNTs. When MWNTs content of the composites is 1 wt%, as compared to neat resin, the flexural strength increases from 143 Mpa to 156 MPa, the modulus increases from 3563 Mpa to 3691 MPa, and the volume and surface resistance of nanocomposites decrease by two orders of magnitude, respectively.

  17. Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites

    Directory of Open Access Journals (Sweden)

    Andrey E. Krauklis

    2018-04-01

    Full Text Available Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer–Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described.

  18. Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites.

    Science.gov (United States)

    Krauklis, Andrey E; Gagani, Abedin I; Echtermeyer, Andreas T

    2018-04-11

    Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR) spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR) spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer-Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described.

  19. Silorane- and high filled-based"low-shrinkage" resin composites: shrinkage, flexural strength and modulus

    Directory of Open Access Journals (Sweden)

    Cesar Augusto Galvão Arrais

    2013-04-01

    Full Text Available This study compared the volumetric shrinkage (VS, flexural strength (FS and flexural modulus (FM properties of the low-shrinkage resin composite Aelite LS (Bisco to those of Filtek LS (3M ESPE and two regular dimethacrylate-based resin composites, the microfilled Heliomolar (Ivoclar Vivadent and the microhybrid Aelite Universal (Bisco. The composites (n = 5 were placed on the Teflon pedestal of a video-imaging device, and VS was recorded every minute for 5 min after 40 s of light exposure. For the FS and FM tests, resin discs (0.6 mm in thickness and 6.0 mm in diameter were obtained (n = 12 and submitted to a piston-ring biaxial test in a universal testing machine. VS, FS, and FM data were submitted to two-way repeated measures and one-way ANOVA, respectively, followed by Tukey's post-hoc test (a = 5%. Filtek LS showed lower VS than did Aelite LS, which in turn showed lower shrinkage than did the other composites. Aelite Universal and Filtek LS exhibited higher FS than did Heliomolar and Aelite LS, both of which exhibited the highest FM. No significant difference in FM was noted between Filtek LS and Aelite Universal, while Heliomolar exhibited the lowest values. Aelite LS was not as effective as Filtek LS regarding shrinkage, although both low-shrinkage composites showed lower VS than did the other composites. Only Filtek LS exhibited FS and FM comparable to those of the regular microhybrid dimethacrylate-based resin composite.

  20. Mechanical properties and polymerization shrinkage of composite resins light-cured using two different lasers.

    Science.gov (United States)

    Kim, Tae-Wan; Lee, Jang-Hoon; Jeong, Seung-Hwa; Ko, Ching-Chang; Kim, Hyung-Il; Kwon, Yong Hoon

    2015-04-01

    The purpose of the present study was to investigate the usefulness of 457 and 473 nm lasers for the curing of composite resins during the restoration of damaged tooth cavity. Monochromaticity and coherence are attractive features of laser compared with most other light sources. Better polymerization of composite resins can be expected. Eight composite resins were light cured using these two lasers and a light-emitting diode (LED) light-curing unit (LCU). To evaluate the degrees of polymerization achieved, polymerization shrinkage and flexural and compressive properties were measured and compared. Polymerization shrinkage values by 457 and 473 nm laser, and LED ranged from 10.9 to 26.8, from 13.2 to 26.1, and from 11.5 to 26.3 μm, respectively. The values by 457 nm laser was significantly different from those by 473 and LED LCU (p0.05). For the tested LCUs, no specific LCU could consistently achieve highest strength and modulus from the specimens tested. Two lasers (457 and 473 nm) can polymerize composite resins to the level that LED LCU can achieve despite inconsistent trends of polymerization shrinkage and flexural and compressive properties of the tested specimens.

  1. Thermal and mechanical behaviour of sub micron sized fly ash reinforced polyester resin composite

    Science.gov (United States)

    Nantha Kumar, P.; Rajadurai, A.; Muthuramalingam, T.

    2018-04-01

    The utilization of particles reinforced resin matrix composites is being increased owing to its lower density and high strength to weight ratio. In the present study, an attempt has been made to synthesize fly ash particles reinforced polyester resin composite for engine cowling application. The thermal stability and mechanical behaviours such as hardness and flexural strength of the composite with 2, 3 and 4 weight % of reinforcement is studied and analyzed. The thermo gravimetric analysis indicates that the higher addition of reinforcement increases the decomposition temperature due to its refractory nature. It is also observed that the hardness increases with higher filler addition owing to the resistance of FA particles towards penetration. The flexural strength is found to increase up to the addition of 3% of FA particles, whereas the polyester resin composite prepared with 4% FA particles addition is observed to have low flexural strength owing to agglomeration of particles.

  2. Preparation and Characterization of Liquid Crystalline Polyurethane/Al2O3/Epoxy Resin Composites for Electronic Packaging

    Directory of Open Access Journals (Sweden)

    Shaorong Lu

    2012-01-01

    Full Text Available Liquid crystalline polyurethane (LCPU/Al2O3/epoxy resin composites were prepared by using LCPU as modifier. The mechanical properties, thermal stability, and electrical properties of the LCPU/Al2O3/epoxy resin composites were investigated systematically. The thermal oxidation analysis indicated that LCPU/Al2O3/epoxy resin composites can sustain higher thermal decomposition temperature. Meanwhile, coefficient of thermal expansion (CTE was also found to decrease with addition of LCPU and nano-Al2O3.

  3. Effect of dentin dehydration and composite resin polymerization mode on bond strength of two self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Pooran Samimi

    2016-01-01

    Full Text Available Background: Dual-cured composite resins are similar to self-cured composite resins in some of their clinical applications due to inadequate irradiation, lack of irradiation, or delayed irradiation. Therefore, incompatibility with self-etch adhesives (SEAs should be taken into account with their use. On the other, the extent of dentin dehydration has a great role in the quality of adhesion of these resin materials to dentin. The aim of this study was to investigate the effect of dentin dehydration and composite resin polymerization mode on bond strength of two SEAs. Materials and Methods: A total of 120 dentinal specimens were prepared from extracted intact third molars. Half of the samples were dehydrated in ethanol with increasing concentrations. Then Clearfil SE Bond (CSEB and Prompt L-Pop (PLP adhesives were applied in the two groups. Cylindrical composite resin specimens were cured using three polymerization modes: (1 Immediate light-curing, (2 delayed light-curing after 20 min, and (3 self-curing. Bond strength was measured using universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and Duncan post hoc tests. Statistical significance was defined at P 0.05. PLP showed significant differences between subgroups with the lowest bond strength in hydrated dentin with delayed light-curing and self-cured mode of polymerization. Conclusion: Within the limitations of this study, a delay in composite resin light-curing or using chemically cured composite resin had a deleterious effect on dentin bond strength of single-step SEAs used in the study.

  4. Characterization of selected LDEF polymer matrix resin composite materials

    Science.gov (United States)

    Young, Philip R.; Slemp, Wayne S.; Witte, William G., Jr.; Shen, James Y.

    1991-01-01

    The characterization of selected graphite fiber reinforced epoxy (934 and 5208) and polysulfone (P1700) matrix resin composite materials which received 5 years and 10 months of exposure to the LEO environment on the Long Duration Exposure Facility is reported. Resin loss and a decrease in mechanical performance as well as dramatic visual effects were observed. However, chemical characterization including infrared, thermal, and selected solution property measurements showed that the molecular structure of the polymeric matrix had not changed significantly in response to this exposure. The potential effect of a silicon-containing molecular contamination of these specimens is addressed.

  5. Multi-wall carbon nanotubes/epoxy resin composites characterization of the starting materials and evaluation of thermal and electrical conductivity

    International Nuclear Information System (INIS)

    Silva, Wellington Marcos da

    2009-01-01

    In this study we investigate the electrical and thermal properties of I) composite materials fabricated with O, I, 0,5 and I wt% of concentric multi-wall carbon nanotubes/epoxy resin (MWNT) dispersed randomly in the resin; 2) MWNT buckypaper/resin composite materials; 3) and neat MWNT buckypaper. Initially, we use the techniques of thermogravimetry, infrared spectroscopy, nuclear magnetic resonance, energy dispersive spectroscopy, x-ray fluorescence, scanning and transmission electron microscopy for a broadening characterization of the starting materials, to evaluate its morphology, purity, chemical composition and structure, in order to optimize the properties of crosslinked resin and, consequently, of the composite systems. Important parameters such as the average molecular mass and the equivalent weight of epoxy resin (DGEBA) were determined by 1 H-NMR analysis and, after that, resin/curing agent relations with Phr 10, 15, 20 and 53,2 were elaborated and investigated by thermogravimetry, the resin/curing agent relation with Phr 10 showed to be the most thermally stable. This stoichiometric relation was used to elaborate the composites. We have evaluated that the effect of adding 10 wt% of the solvent acetone to the epoxy resin preparation does not alter its properties so we have adopted two routes to fabricate the composites. In the first route we used 10 wt% of acetone and, in the second the MWNT were dispersed in the matrix without using the solvent. However, no significant difference was observed for the dispersion of the bundle tubes in both systems. The electrical conductivity of the composites and buckypapers was evaluated by impedance spectroscopy and the thermal conductivity by the flash laser flash method. Only the buckypapers presented high values for electrical conductivity (10 3 S.m -1 ). The composite systems presented values of 10 -3 S.m -1 , only a bit different from the value of the crosslinked resin. For thermal conductivity, the values for the

  6. Composition of atmospheric precipitation. I. Sampling technique. Use of ion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Egner, H; Eriksson, E; Emanuelsson, A

    1947-01-01

    In order to investigate the composition of atmospheric precipitations in Sweden, a technique using ion exchange resins has been developed. The possibilities of nitrate reduction, and ammonia losses, when the precipitation is collected in zinc gauges is stressed. Glass funnels are used, and they are effectively protected from bird droppings. The ion exchange resins so far available are quite serviceable but show some deficiencies as to stability, and activity in alkaline solutions. New resins, which are not yet available, seem to offer definite advantages.

  7. Repair bond strength of resin composite to bilayer dental ceramics

    Science.gov (United States)

    2018-01-01

    PURPOSE The purpose of this study was to investigate the effect of various surface treatments (ST) on the shear bond strength of resin composite to three bilayer dental ceramics made by CAD/CAM and two veneering ceramics. MATERIALS AND METHODS Three different bilayer dental ceramics and two different veneering ceramics were used (Group A: IPS e.max CAD+IPS e.max Ceram; Group B: IPS e.max ZirCAD+IPS e.max Ceram, Group C: Vita Suprinity+Vita VM11; Group D: IPS e.max Ceram; Group E: Vita VM11). All groups were divided into eight subgroups according to the ST. Then, all test specimens were repaired with a nano hybrid resin composite. Half of the test specimens were subjected to thermocycling procedure and the other half was stored in distilled water at 37℃. Shear bond strength tests for all test specimens were carried out with a universal testing machine. RESULTS There were statistically significant differences among the tested surface treatments within the all tested fracture types (P.00125). CONCLUSION This study revealed that HF etching for glass ceramics and sandblasting for zirconia ceramics were adequate for repair of all ceramic restorations. The effect of ceramic type exposed on the fracture area was not significant on the repair bond strength of resin composites to different ceramic types. PMID:29713430

  8. Curing behaviour of epoxy resin/graphite composites containing ionic liquid

    International Nuclear Information System (INIS)

    Guo Baochun; Wan Jingjing; Lei Yanda; Jia Demin

    2009-01-01

    By adopting the isoconversional method, subtle changes in the curing activation energy (E α ) among epoxy resin/graphite composites by the inclusion of expanded graphite (EG), ionic liquid of 1-butyl-3-methyl-imidazolium hexafluorophosphate ([BMIm]PF 6 ) or their combination are shown in the whole conversion range. At lower concentrations (1 phr) of EG, compared with the E α of the neat epoxy resin, the composite with EG has a lower E α before the gelation, and a higher E α after the gelation. At higher concentrations of EG, however, in the whole conversion range, the composite with EG shows a higher E α compared with the neat epoxy resin. As the curing proceeded, a peculiar increase in E α is found in systems containing [BMIm]PF 6 . Due to the formation of hydrogen bonding between [BMIm]PF 6 and the hardener (Jeffamine), the reactivity of Jeffamine is considerably decreased, leading to a much higher E α in [BMIm]PF 6 -containing systems, especially at higher conversion. In systems containing a combination of [BMIm]PF 6 and EG, due to the interactions between EG and [BMIm]PF 6 , the shielding effect provided by the well-dispersed EG sheets constrains the formation of the hydrogen bonding between [BMIm]PF 6 and Jeffamine, leading to lowered E α compared with that for the system containing [BMIm]PF 6 only.

  9. Randomized Clinical Trial of Indirect Resin Composite and Ceramic Veneers : Up to 3-year Follow-up

    NARCIS (Netherlands)

    Gresnigt, Marco M. M.; Kalk, Warner; Ozcan, Mutlu

    2013-01-01

    Purpose: This randomized controlled split-mouth clinical trial evaluated the short-term survival rate of indirect resin composite and ceramic laminate veneers. Materials and Methods: A total of 10 patients (mean age: 48.6 years) received 46 indirect resin composite (Estenia; n = 23) and ceramic

  10. Effect of Different Surface Treatments on Repair Micro-shear Bond Strength of Silica- and Zirconia-filled Composite Resins

    Directory of Open Access Journals (Sweden)

    Mohammad Joulaei

    2012-11-01

    Full Text Available Background and aims. Effect of surface treatments on repair bond strength of aged composite resins might be different due to their dissimilar fillers. The aim was to evaluate the effect of different surface treatments on repair micro-shear bond strength (µSBS of silica- (Spectrum TPH and zirconia-filled (Filtek Z250 composite resins. Materials and methods. Twenty-seven composite resin blocks were made from each type of composite resin: Z250 and Spectrum TPH. After aging, blocks of each type were randomly divided into three groups according to surface treatments: alloy primer, silane, and only surface roughening. Subsequently, each group was further subdivided into 3 subgroups based on the adhesive system used: Single Bond, Clearfil SE Bond, and Margin Bond. Four composite resin columns were added on each block. After thermocycling, µSBStest were done at cross head speed of 0.5 mm/min. Data was analysed using multifactor ANOVA, one-way ANOVA and a post-hoc Bonferroni tests (α = 0.05. Results. Analysis of data showed that the effect of composite resin type was not significant (p > 0.05, but the effects of the type of surface treatment (p = 0.01 and the type of adhesive system (p = 0.01 were significant on repair µSBS. In addition, the cumulative effect of the composite type-surface treatment and the composite type with the type of adhesive system were not statistically significant (p > 0.05. However, the cumulative effects of the adhesive system-surface treatment (p = 0.03 and the composite type-the adhesive system-surface treatments (p = 0.002 were significant. Conclusion. Although repair µSBS values of both silica- and zirconia-filled composite resins were similar, use of different combinations of surface treatments and adhesive systems affected their repair µSBS differently.

  11. Effect of Different Surface Treatments on Repair Micro-shear Bond Strength of Silica- and Zirconia-filled Composite Resins

    Science.gov (United States)

    Joulaei, Mohammad; Bahari, Mahmoud; Ahmadi, Anahid; Savadi Oskoee, Siavash

    2012-01-01

    Background and aims Effect of surface treatments on repair bond strength of aged composite resins might be different due to their dissimilar fillers. The aim was to evaluate the effect of different surface treatments on repair micro-shear bond strength (µSBS) of silica- (Spectrum TPH) and zirconia-filled (Filtek Z250) composite resins. Materials and methods Twenty-seven composite resin blocks were made from each type of composite resin: Z250 and Spectrum TPH. After aging, blocks of each type were randomly divided into three groups according to surface treatments: alloy primer, silane, and only surface roughening. Subsequently, each group was further subdivided into 3 subgroups based on the adhesive system used: Single Bond, Clearfil SE Bond, and Margin Bond. Four composite resin columns were added on each block. After thermocycling, µSBStest were done at cross head speed of 0.5 mm/min. Data was analysed using multifactor ANOVA, one-way ANOVA and a post-hoc Bonferroni tests (α = 0.05). Results Analysis of data showed that the effect of composite resin type was not significant (p > 0.05), but the effects of the type of surface treatment (p = 0.01) and the type of adhesive system (p = 0.01) were significant on repair µSBS. In addition, the cumulative effect of the composite type-surface treatment and the composite type with the type of adhesive system were not statistically significant (p > 0.05). However, the cumulative effects of the adhesive system-surface treatment (p = 0.03) and the composite type-the adhesive system-surface treatments (p = 0.002) were significant. Conclusion Although repair µSBS values of both silica- and zirconia-filled composite resins were similar, use of different combinations of surface treatments and adhesive systems affected their repair µSBS differently. PMID:23277859

  12. Assessment of Tensile Bond Strength of Fiber-Reinforced Composite Resin to Enamel Using Two Types of Resin Cements and Three Surface Treatment Methods

    Directory of Open Access Journals (Sweden)

    Tahereh Ghaffari

    2015-10-01

    Full Text Available Background: Resin-bonded bridgework with a metal framework is one of the most conservative ways to replace a tooth with intact abutments. Visibility of metal substructure and debonding are the complications of these bridgeworks. Today, with the introduction of fiber-reinforced composite resins, it is possible to overcome these complications. The aim of this study was to evaluate the bond strength of fiber-reinforced composite resin materials (FRC to enamel. Methods: Seventy-two labial cross-sections were prepared from intact extracted teeth. Seventy-two rectangular samples of cured Vectris were prepared and their thickness was increased by adding Targis. The samples were divided into 3 groups for three different surface treatments: sandblasting, etching with 9% hydrofluoric acid, and roughening with a round tapered diamond bur. Each group was then divided into two subgroups for bonding to etched enamel by Enforce and Variolink II resin cements. Instron universal testing machine was used to apply a tensile force. The fracture force was recorded and the mode of failure was identified under a reflective microscope. Results: There were no significant differences in bond strength between the three surface treatment groups (P=0.53. The mean bond strength of Variolink II cement was greater than that of Enforce (P=0.04. There was no relationship between the failure modes (cohesive and adhesive and the two cement types. There was some association between surface treatment and failure mode. There were adhesive failures in sandblasted and diamond-roughened groups and the cohesive failure was dominant in the etched group. Conclusion: It is recommended that restorations made of fiber-reinforced composite resin be cemented with VariolinkII and surface-treated by hydrofluoric acid.   Keywords: Tensile bond strength; surface treatment methods; fiber-reinforced composite resin

  13. Degree of conversion of nanofilled and microhybrid composite resins photo-activated by different generations of LEDs.

    Science.gov (United States)

    Ribeiro, Benicia Carolina Iaskieviscz; Boaventura, Juliana Maria Capelozza; Brito-Gonçalves, Joel de; Rastelli, Alessandra Nara de Souza; Bagnato, Vanderlei Salvador; Saad, José Roberto Cury

    2012-01-01

    This study aimed at evaluating the degree of conversion (DC) of four composite resins, being one nanofilled and 3 microhybrid resins, photo-activated with second- and third-generation light-emitting diodes (LEDs). Filtek™ Z350 nanofilled composite resins and Amelogen® Plus, Vit-l-escence™ and Opallis microhybrid resins were photo-activated with two second-generation LEDs (Radii-cal and Elipar Free Light™ 2) and one third-generation LED (Ultra-Lume LED 5) by continuous light mode, and a quartz halogen-tungsten bulb (QHT, control). After 24 h of storage, the samples were pulverized into fine powder and 5 mg of each material were mixed with 100 mg of potassium bromide (KBr). After homogenization, they were pressed, which resulted in a pellet that was evaluated using an infrared spectromer (Nexus 470, Thermo Nicolet) equipped with TGS detector using diffuse reflectance (32 scans, resolution of 4 cm(-1)) coupled to a computer. The percentage of unreacted carbon-carbon double bonds (% C=C) was determined from the ratio of absorbance intensities of aliphatic C=C (peak at 1637 cm-1) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm-1). The ANOVA showed a significant effect on the interaction between the light-curing units (LCUs) and the composite resins (presin (Filtek™ Z350) and Opallis when photo-activated by the halogen lamp (QTH) had the lowest DC compared with the other microhybrid composite resins. The DC of the nanofilled resin (Filtek™ Z350) was also lower using LEDs. The highest degrees of conversion were obtained using the third-generation LED and one of second-generation LEDs (Elipar Free Light™ 2). The nanofilled resin showed the lowest DC, and the Vit-l-escence™ microhybrid composite resin showed the highest DC. Among the LCUs, it was not possible to establish an order, even though the second-generation LED Radii-cal provided the lowest DC.

  14. Effects of polishing procedures on color stability of composite resins

    Directory of Open Access Journals (Sweden)

    Ahmet Umut Güler

    2009-04-01

    Full Text Available The purpose of this study was to investigate the effect of different polishing methods on color stability of posterior, universal and nanohybrid composite resin restorative materials upon exposure to a staining agent. Twenty-five specimens were prepared for each of 5 different composite resins (Filtek Z250, Filtek P60, Quadrant LC, Grandio and Filtek Supreme. Specimens were divided into 5 groups and different polishing procedures, including polishing discs (Pd, polishing discs then diamond polishing paste (PdP, polishing discs then a liquid polishing system (Biscover (PdB, and combinations of these (PdPB were used. Unpolished specimens served as the control (C. The specimens were stored for 48 h in a coffee solution. The color of all specimens was measured before and after exposure with a colorimeter, and total color change (DE* were calculated. The data were analyzed with a two-way ANOVA and the means were compared by Tukey HSD test (a=0.05. The lowest color difference was observed in the groups PdP and C, while the highest color difference was observed in PdPB, and PdB. When comparing the five different restorative materials, no significant difference was observed between FiltekP60 and FiltekZ250, and these materials demonstrated significantly less color change than Quadrant LC and the nanohybrid materials (Grandio, Filtek Supreme. The posterior (Filtek P60 and universal (Filtek Z250 composite resin restorative materials, which do not contain tetraethyleneglycol dimethacrylate (TEGDMA, were found to be less stainable than the nanohybrid (Grandio, Filtek Supreme and universal (Quadrant LC composite resins, which contain TEGDMA. The use of diamond polishing paste after polishing with polishing discs significantly decreased staining when compared to the groups that used polishing discs alone, for all restorative materials tested. The highest color change values were obtained for the specimens that were polished with the Biscover liquid polish

  15. Composite panels made with biofiber or office wastepaper bonded with thermoplastic and/or thermosetting resin

    Science.gov (United States)

    James H. Muehl; Andrzej M. Krzysik; Poo Chow

    2004-01-01

    The purpose of this study was to evaluate two groups of composite panels made from two types of underutilized natural fiber sources, kenaf bast fiber and office wastepaper, for their suitability in composite panels. All panels were made with 5% thermosetting phenol-formaldehyde (PF) resin and 1.5% wax. Also, an additional 10% polypropylene (PP) thermoplastic resin was...

  16. Analysis of the microstructure and mechanical performance of composite resins after accelerated artificial aging.

    Science.gov (United States)

    De Oliveira Daltoé, M; Lepri, C Penazzo; Wiezel, J Guilherme G; Tornavoi, D Cremonezzi; Agnelli, J A Marcondes; Reis, A Cândido Dos

    2013-03-01

    Researches that assess the behavior of dental materials are important for scientific and industrial development especially when they are tested under conditions that simulate the oral environment, so this work analyzed the compressive strength and microstructure of three composite resins subjected to accelerated artificial aging (AAA). Three composites resins of 3M (P90, P60 and Z100) were analyzed and were obtained 16 specimens for each type (N.=48). Half of each type were subjected to UV-C system AAA and then were analyzed the surfaces of three aged specimens and three not aged of each type through the scanning electron microscope (SEM). After, eight specimens of each resin, aged and not aged, were subjected to compression test. After statistical analysis of compressive strength values, it was found that there was difference between groups (α aged P60 presented lower values of compressive strength statistically significant when compared to the not subject to the AAA. For the other composite resins, there was no difference, regardless of aging, a fact confirmed by SEM. The results showed that the AAA influenced the compressive strength of the resin aged P60; confirmed by surface analysis by SEM, which showed greater structural disarrangement on surface material.

  17. Degradation of dental resin composites during intra-oral wear

    NARCIS (Netherlands)

    Yulianto, Heribertus Dedy Kusuma

    2017-01-01

    Dental resin composites have become an integral part of modern dentistry and used worldwide to restore missing tooth structures, to modify tooth color and anatomical contour, and to enhance aesthetics and function. The dentist should be aware that, the aggressive complexity of the oral environment

  18. Influence of Finishing and Polishing Techniques and Abrasion on Transmittance and Roughness of Composite Resins.

    Science.gov (United States)

    Carneiro, Pma; Ramos, T M; de Azevedo, C S; de Lima, E; de Souza, Shj; Turbino, M L; Cesar, P F; Matos, A B

    The aim of this study was to evaluate the influence of finishing and polishing systems and toothbrush abrasion on transmittance (T) and surface roughness (Ra) of three composite resins (Filtek Z350 XT, Tetric N-Ceram, and IPS Empress Direct). Eighteen resin disks (10 mm diameter × 2 mm thick) finished by polyester strips had initial surface smoothness recorded, representing phase 1 (P1). Specimens were divided into three groups (n=6) according to the finishing/polishing instrument used (OneGloss, TopGloss, and Sof-Lex) to compose phase 2 samples (P2). Then specimens were subjected to 514 cycles of toothbrush simulation using a toothpaste slurry, with a constant load applied to soft bristles, and were then washed (phase 3=P3). After each phase, the specimens were examined by an optical profiler and spectrophotometer to measure Ra and T. Data were analyzed by analysis of variance, Tukey and Pearson tests. T values were statistically influenced by composite resin ( p=0.000) and phase of measurement ( p=0.000) factors, while the finishing/polishing system used ( p=0.741) did not affect T. On the other hand, Ra values were statistically affected by the factor finishing/polishing system ( p=0.000), but not by composite resin ( p=0.100) and phase of measurement ( p=0.451). Tetric N-Ceram and Empress Direct presented higher values of roughness when polished by OneGloss, while TopGloss and Sof-Lex showed a lower roughness. It can be concluded that composite resins transmitted more light after dental abrasion. Transmittance of composite resins was not modified by the distinct roughness created by finishing/polishing instruments.

  19. Resin bond to indirect composite and new ceramic/polymer materials: a review of the literature.

    Science.gov (United States)

    Spitznagel, Frank A; Horvath, Sebastian D; Guess, Petra C; Blatz, Markus B

    2014-01-01

    Resin bonding is essential for clinical longevity of indirect restorations. Especially in light of the increasing popularity of computer-aided design/computer-aided manufacturing-fabricated indirect restorations, there is a need to assess optimal bonding protocols for new ceramic/polymer materials and indirect composites. The aim of this article was to review and assess the current scientific evidence on the resin bond to indirect composite and new ceramic/polymer materials. An electronic PubMed database search was conducted from 1966 to September 2013 for in vitro studies pertaining the resin bond to indirect composite and new ceramic/polymer materials. The search revealed 198 titles. Full-text screening was carried out for 43 studies, yielding 18 relevant articles that complied with inclusion criteria. No relevant studies could be identified regarding new ceramic/polymer materials. Most common surface treatments are aluminum-oxide air-abrasion, silane treatment, and hydrofluoric acid-etching for indirect composite restoration. Self-adhesive cements achieve lower bond strengths in comparison with etch-and-rinse systems. Thermocycling has a greater impact on bonding behavior than water storage. Air-particle abrasion and additional silane treatment should be applied to enhance the resin bond to laboratory-processed composites. However, there is an urgent need for in vitro studies that evaluate the bond strength to new ceramic/polymer materials. This article reviews the available dental literature on resin bond of laboratory composites and gives scientifically based guidance for their successful placement. Furthermore, this review demonstrated that future research for new ceramic/polymer materials is required. © 2014 Wiley Periodicals, Inc.

  20. Three-dimensional temperature field model of thermally decomposing resin composite irradiated by laser

    International Nuclear Information System (INIS)

    Chen Minsun; Jiang Houman; Liu Zejin

    2011-01-01

    Fundamental equations governing the temperature field of thermally decomposing resin composite irradiated by laser are derived from mass and energy conservation laws with the control Janume method. The thermal decomposition of resin is described by a multi-step model. An assumption is proposed that the flow of pyrolysis gas is one-dimensional, which makes it possible to consider the influence of pyrolysis gas convective transport and realize the closure of the three-dimensional model without introducing mechanical quantities. In view of the anisotropy of resin composite, expressions of the thermal conductivities of partially pyrolyzed material are deduced, as well as the computing formula for the laser absorption coefficient of partially pyrolyzed material. The energy conservation equation is consistent with reference under some simplifications. (authors)

  1. Improving mechanical properties of flowable dental composite resin by adding silica nanoparticles

    Directory of Open Access Journals (Sweden)

    Baloš Sebastian

    2013-01-01

    Full Text Available Background/Aim. The main drawback of flowable dental composite resin is low strength compared to conventional composite resin, due to a low amount of filler, neccessary for achieving low viscosity and ease of handling. The aim of this study was to improve mechanical properties of flowable dental composite resin by adding small amount of nanoparticles, which would not compromise handling properties. Methods. A commercially available flowable dental composite resin material was mixed with 7 nm aftertreated hydrophobic fumed silica and cured by an UV lamp. Four sets of samples were made: control sample (unmodified, the sample containing 0.05%, 0.2% and 1% nanosilica. Flexural modulus, flexural strength and microhardness were tested. One-way ANOVA followed by Tukey’s test with the significance value of p < 0.05 was performed to statistically analyze the obtained results. Furthermore, differential scanning calorimetry (DSC and SEM analysis were performed. To asses handling properties, slumping resistance was determined. Results. It was found that 0.05% is the most effective nanosilica content. All the tested mechanical properties were improved by a significant margin. On the other hand, when 0.2% and 1% nanosilica content was tested, different results were obtained, some of the mechanical properties even dropped, while some were insignificantly improved. The difference between slumping resistance of unmodified and modified samples was found to be statistically insignificant. Conclusions. Low nanosilica addition proved more effective in improving mechanical properties compared to higher additions. Furthermore, handling properties are unaffected by nanosilica addition.

  2. Randomized 3-year Clinical Evaluation of Class I and II Posterior Resin Restorations Placed with a Bulk-fill Resin Composite and a One-step Self-etching Adhesive

    DEFF Research Database (Denmark)

    van Dijken, Jan Wv; Pallesen, Ulla

    2015-01-01

    PURPOSE: To evaluate the 3-year clinical durability of the flowable bulk-fill resin composite SDR in Class I and Class II restorations. MATERIALS AND METHODS: Thirty-eight pairs of Class I and 62 pairs of Class II restorations were placed in 44 male and 42 female patients (mean age 52.4 years......). Each patient received at least two extended Class I or Class II restorations that were as similar as possible. In all cavities, a one-step self-etching adhesive (XenoV+) was applied. One of the cavities of each pair was randomly assigned to receive the flowable bulk-fill resin composite SDR...... in increments up to 4 mm as needed to fill the cavity 2 mm short of the occlusal cavosurface. The occlusal part was completed with an ormocer-based nanohybrid resin composite (Ceram X mono+). In the other cavity, only the resin composite CeramX mono+ was placed in 2 mm increments. The restorations were...

  3. Do the monomers release from the composite resins after artificial aging?

    Science.gov (United States)

    Tokay, Ugur; Koyuturk, Alp Erdin; Aksoy, Abdurrahman; Ozmen, Bilal

    2015-04-01

    The aim of this study is to measure the effect of thermal cycling on the amount of monomer released from three different composite materials by HPLC analysis method. Three different composite materials, inlay composite, posterior composite and micro-hybrid composite were used. Sixty cylinder specimens each with a dimension of approximately 1 cm width and 3 mm depth, were prepared before experiments were carried out. Inlay composite material was polymerized according to manufacturers' instructions. Thermal cycling device was used to simulate thermal differences which occur in the mouth media. Monomers were analyzed using HPLC technic after thermal cycling process. The amount of ethoxylated Bis-GMA and urethane dimethacrylate (UDMA) in inlay composite material, the amount of ethoxylated Bis-GMA in posterior composite material, the amount of ethoxylated Bis-GMA and triethyleneglycol dimethacrylate (TEGDMA) in micro-hybrid composite material were investigated. Monomer release of thermal cycles levels showed a linear increase in UDMA and TEGDMA (P < 0.05). In terms of thermal cycles levels, Bis-EMA released from posterior composite showed a cubic change (P < 0.001). It was observed that use of additional polymerization processes might have positive effect on the decrease of residual monomer. In the light of the results, we suggest that indirect composite resins have more outstanding features than direct composite resins in terms of biocompatibility. © 2015 Wiley Periodicals, Inc.

  4. Comparison of clasp retention on enamel and composite resin-recontoured abutments following repeated removal in vitro.

    Science.gov (United States)

    Zarrati, Simindokht; Sadighpour, Leyla; Jahanian, Ghasem

    2010-04-01

    Loss of prosthetic retention over time is a concern with removable prostheses. Use of composite resin to modify an abutment contour receiving a removable partial denture clasp may offer a reasonable, less invasive method of improving removable prosthesis retention. The purpose of this study was to evaluate the removal force of clasps over composite resin-recontoured abutments during a simulated 4 years of service. Twenty first mandibular premolars were selected to form 2 groups of specimens (n=5) resembling a tooth-supported edentulous space. A packable composite resin (Filtek P60) was used to create a 0.25-mm undercut on the buccal abutment surfaces of the composite resin group. Teeth in the natural abutment group were mounted in angulation to produce 0.25-mm undercuts on the buccal surfaces. The chrome-cobalt framework consisted of 2 individually fabricated T-clasps. Both groups were subjected to 4500 cycles of repeated removal using a small shaker. Removal forces were recorded before the repeated removal test (T(0)), after 500 and 1000 cycles, and at 1000-cycle intervals thereafter. The mean values of forces between the 2 groups were compared at each stage using the Mann-Whitney test (alpha=.05). No debonding occurred during the test. At T(0), the highest and lowest force values were observed in the composite resin group (3.75 N and 17.5 N, respectively). There was a significant difference between the removal forces of the 2 groups after 500 cycles and at test completion (P=.008). Retention loss was 3 times greater in the composite resin group than in the natural abutments group (53.65% vs. 15.80%). Within the limitations of the study, removal forces of the composite resin-recontoured abutments were threefold less than those of natural abutments after 4 years of simulated service. Copyright 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  5. Marginal integrity of low-shrinkage and methacrylate-based composite resins: Effect of three different hemostatic agents

    Science.gov (United States)

    Khoroushi, Maryam; Sahraneshin-Samani, Mahsa

    2016-01-01

    Background Moisture control is very important in restorative procedures in dentistry. Use of hemostatic agents helps control moisture; however, they might result in changes on enamel and dentin surfaces, affecting composite resin bond quality. The aim of this in vitro study was to evaluate the marginal microleakage of two different composite resins with the use of three different hemostatic agents. Material and Methods Standardized Class V cavities were prepared on the buccal and lingual surfaces of 48 premolars with cervical margins 1 mm apical to the cementoenamel junction (CEJ). The samples were randomly divided into 8 groups. In groups 1 to 4, an etch-and-rinse adhesive (Adper Single Bond) was applied as the bonding system, followed by exposure to different hemostatic agent: group 1: no hemostatic agent (control); group 2: ViscoStat; group 3: ViscoStat Clear; and group 4: trichloracetic acid, as hemostatic agents. The cavities were restored with Z-250 composite resin. In group 5 to 8 Silorane System Adhesive (Filtek P90 Adhesive) was applied as a bonding agent, followed by exposure to different hemostatic agents in a manner similar to that in groups 1to 4. The cavities were restored with Filtek P90, a low-shrinkage composite resin. The samples in each group were evaluated for dye penetration under a stereomicroscope at ×36 after 24 hours and a 500-round thermocycling procedure at enamel and dentin margins. Statistical analysis was carried out using Kruskal-Wallis and Mann-Whitney tests (α=0.05). Results Z-250 composite resin exhibited significantly higher dentin microleakage scores compared to Filtek P90 (P = 0.004). Trichloracetic acid increased dentin microleakage with Filtek P90 (P=0.033). Conclusions Under the limitations of this in vitro study, application of hemostatic agents did not affect microleakage of the two tested composite resins except for trichloracetic acid that increased marginal microleakage when used with Filtek P90. Key words:Composite

  6. The study on the ion exchange behavior of metal ions using composite ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kukki; Lee, Kunjai [Nuclear Engineering Department Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Kim, Youngkyun [Korea Institute of Nuclear Safety, Daejon (Korea, Republic of); Lee, Sangjin; Yang, Hoyeon; Ha, Jonghyun [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2002-04-15

    In this study, a series of stepwise procedures to prepare a new organic-inorganic composite magnetic resin with phenol sulphonic-formaldehyde and freshly formed iron ferrite was established, based upon wet-and-neutralization method for synthesizing iron ferrite and pearl-polymerization method for synthesizing rigid bead-type composite resin. And a separation of metal ions in the liquid radioactive waste have been performed using organic-inorganic composite magnetic resin with phenol sulphonic-formaldehyde and freshly formed iron ferrite. The PSF-F (phenol sulphonic formaldehyde-iron ferrite) composite resin prepared by the above method shows stably high removal efficiency to Co(II), Fe, Cs species from wastewater in a wide range of solution pH. The wide range of applicable solution pH (i. e. pH 4.0 to 10.3) implies that the PSF-F composite resin overcomes the limitations of the conventional ferrite process which is practically applicable only to alkaline conditions. The experiment proceeded using batch reactor in a constant temperature with water bath. The experiments divided into three parts. The first one is TG/DTA (Thermogravimetry / Differential Thermal Analysis) which can analyze the trend of pyrolysis of PSF-F ion exchanger. The Second one is equilibrium experiment in which the separation factor of metal ions and Langmuir, Freundlich isotherm was achieved. The last one is kinetics experiment in which the equilibrium reaction time and removal efficiency is estimated.

  7. The study on the ion exchange behavior of metal ions using composite ion exchange resin

    International Nuclear Information System (INIS)

    Kim, Kukki; Lee, Kunjai; Kim, Youngkyun; Lee, Sangjin; Yang, Hoyeon; Ha, Jonghyun

    2002-01-01

    In this study, a series of stepwise procedures to prepare a new organic-inorganic composite magnetic resin with phenol sulphonic-formaldehyde and freshly formed iron ferrite was established, based upon wet-and-neutralization method for synthesizing iron ferrite and pearl-polymerization method for synthesizing rigid bead-type composite resin. And a separation of metal ions in the liquid radioactive waste have been performed using organic-inorganic composite magnetic resin with phenol sulphonic-formaldehyde and freshly formed iron ferrite. The PSF-F (phenol sulphonic formaldehyde-iron ferrite) composite resin prepared by the above method shows stably high removal efficiency to Co(II), Fe, Cs species from wastewater in a wide range of solution pH. The wide range of applicable solution pH (i. e. pH 4.0 to 10.3) implies that the PSF-F composite resin overcomes the limitations of the conventional ferrite process which is practically applicable only to alkaline conditions. The experiment proceeded using batch reactor in a constant temperature with water bath. The experiments divided into three parts. The first one is TG/DTA (Thermogravimetry / Differential Thermal Analysis) which can analyze the trend of pyrolysis of PSF-F ion exchanger. The Second one is equilibrium experiment in which the separation factor of metal ions and Langmuir, Freundlich isotherm was achieved. The last one is kinetics experiment in which the equilibrium reaction time and removal efficiency is estimated

  8. Effect of different light curing units on Knoop hardness and temperature of resin composite.

    Science.gov (United States)

    Guiraldo, Ricardo Danil; Consani, Simonides; Xediek Consani, Rafael Leonardo; Mendes, Wilson Batista; Lympius, Thais; Coelho Sinhoreti, Mario Alexandre

    2009-01-01

    To evaluate the influence of quartz tungsten halogen and plasma arc curing (PAC) lights on Knoop hardness and change in polymerization temperature of resin composite. Filtek Z250 and Esthet X composites were used in the shade A3. The temperature increase was registered with Type-k thermocouple connected to a digital thermometer (Iopetherm 46). A self-cured polymerized acrylic resin base was built in order to guide the thermocouple and to support the dentin disk of 1.0 mm thickness obtained from bovine tooth. On the acrylic resin base, elastomer mold of 2.0 mm was adapted. The temperature increase was measured after composite light curing. After 24 h, the specimens were submitted to Knoop hardness test (HMV-2000, Shimadzu, Tokyo, Japan). Data were submitted to ANOVA and Tukey's test (alpha = 0.05). For both composites, there were no significant differences (P > 0.05) in the top surface hardness; however, PAC promoted statistically lower (P 0.05). The standardized radiant exposure showed no influence on the temperature increase of the composite, however, showed significant effect on hardness values.

  9. Interface and its effect on the interlaminate shear strength of novel glass fiber/hyperbranched polysiloxane modified maleimide-triazine resin composites

    International Nuclear Information System (INIS)

    Liu Ping; Guan Qingbao; Gu Aijuan; Liang Guozheng; Yuan Li; Chang Jianfei

    2011-01-01

    Interface is Key topic of developing advanced fiber reinforced polymeric composites. Novel advanced glass woven fabric (GF) reinforced composites, coded as GF/mBT, were prepared, of which the matrix resin was hyperbranched polysiloxane (HBPSi) modified maleimide-triazine (mBT) resin. The influence of the composition of the matrix on the interfacial nature of the GF/mBT composites were studied and compared with that of the composite based on GF and BT resin using contact angle, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and dielectric properties over wide frequency and temperature ranges. Results show that the interfacial nature of the composites is dependent on the chemistries of the matrices, mBT matrices have better interfacial adhesion with GF than BT resin owing to the formation of chemical and hydrogen bonds between mBT resin and GF; while in the case of mBT resins, the content of HBPSi also plays an important role on the interfacial feature and thus the macro-performance. Specifically, with increasing the content of HBPSi in the matrix, the interlaminate shear strength of corresponding composites significantly improves, demonstrating that better interfacial adhesion guarantees outstanding integrated properties of the resultant composites.

  10. Diffusion through composite materials made with thermosetting resins

    International Nuclear Information System (INIS)

    Morin, Bruno.

    1981-08-01

    Medium and low-level radioactive wastes may be coated in a solid matrix mainly made with thermosetting resins: the study of water and cesium migration through composite materials made with thermosetting resins is usefull to compare the water tightness of different coatings. Disks with a thickness of two millimeters were used to measure the water absorption. Diffusion cells including a plane membrane the thickness of which was at least 70μ were used to measure the diffusion of cesium 137. The diffusion coefficient of water in pure thermosetting resins, polyester or epoxyde, is about 10 -9 cm 2 .s -1 ; the diffusion coefficients of cesium in the same materials are about 10 -12 cm 2 .s -1 ; the introduction of solid particles in these polymers generally induces an acceleration of the diffusion process: the diffusion coefficient may reach 10 -8 cm 2 .s -1 . This lost of water-tightness may be reduced either by rendering insoluble the filler mixed to the polymer, or by diminushing the porosity of the interfacial zones by improving the bonding between the polymer and the filler [fr

  11. Effect of reinforcement with resin composite on fracture strength of structurally compromised roots.

    Science.gov (United States)

    Fukui, Yuji; Komada, Wataru; Yoshida, Keiichi; Otake, Shiho; Okada, Daizo; Miura, Hiroyuki

    2009-09-01

    This study was aimed at evaluating the fracture resistance of structurally compromised roots restored with four different post and core systems. Thirty-two bovine roots were uniformly shaped to simulate human mandibular premolar roots. The roots were divided into four groups based on the type of restoration: cemented cast post and core (Group MC), resin composite build-up (Group CR), resin composite and prefabricated glass fiber post build-up (Group FRC), and thick-layer dual-cured resin composite-reinforced small-diameter tapered cast post and core (Group CRM). After a static loading test, the failure mode and fracture resistance were recorded. Group CRM (719.38+/-196.73 N) exhibited a significantly high fracture resistance compared with the other groups (Group MC: 429.56+/-82.43 N; Group CR: 349.56+/-66.21 N; Group FRC: 398.94+/-112.71 N; pCRM exhibited better mechanical properties for structurally compromised roots with no ferrules, although all types of restorations showed non-restorable fracture modes.

  12. Degree of conversion of nanofilled and microhybrid composite resins photo-activated by different generations of LEDs

    Directory of Open Access Journals (Sweden)

    Benicia Carolina Iaskieviscz Ribeiro

    2012-04-01

    Full Text Available OBJECTIVE:This study aimed at evaluating the degree of conversion (DC of four composite resins, being one nanofilled and 3 microhybrid resins, photo-activated with second- and third-generation light-emitting diodes (LEDs. MATERIAL AND METHODS: Filtek TM Z350 nanofilled composite resins and Amelogen® Plus, Vit-l-escenceTM and Opallis microhybrid resins were photo-activated with two second-generation LEDs (Radii-cal and Elipar Free LightTM 2 and one third-generation LED (Ultra-Lume LED 5 by continuous light mode, and a quartz halogen-tungsten bulb (QHT, control. After 24 h of storage, the samples were pulverized into fine powder and 5 mg of each material were mixed with 100 mg of potassium bromide (KBr. After homogenization, they were pressed, which resulted in a pellet that was evaluated using an infrared spectromer (Nexus 470, Thermo Nicolet equipped with TGS detector using diffuse reflectance (32 scans, resolution of 4 cm-1 coupled to a computer. The percentage of unreacted carbon-carbon double bonds (% C=C was determined from the ratio of absorbance intensities of aliphatic C=C (peak at 1637 cm-1 against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm-1. RESULTS: The ANOVA showed a significant effect on the interaction between the light-curing units (LCUs and the composite resins (p<0.001. The Tukey’s test showed that the nanofilled resin (FiltekTM Z350 and Opallis when photo-activated by the halogen lamp (QTH had the lowest DC compared with the other microhybrid composite resins. The DC of the nanofilled resin (FiltekTM Z350 was also lower using LEDs. The highest degrees of conversion were obtained using the third-generation LED and one of second-generation LEDs (Elipar Free LightTM 2. CONCLUSIONS: The nanofilled resin showed the lowest DC, and the Vit-l-escenceTM microhybrid composite resin showed the highest DC. Among the LCUs, it was not possible to establish an order, even though the second

  13. Investigation of the photoluminescence properties of composite optical resins containing high lanthanide content

    International Nuclear Information System (INIS)

    Wang Dongmei; Wang Fuxiang; Peng Weixian

    2012-01-01

    Novel composite optical resins with high lanthanide content have been synthesized through a free radical copolymerization of methacrylic acid (MA), styrene (St) and Eu(DBM) 3 ·H 2 O nanocrystals. We characterized the structure, the thermal properties, dimensions and photoluminescence properties of Eu(DBM) 3 ·H 2 O nanocrystals. Our results indicated that the diameters of the Eu(DBM) 3 ·H 2 O nanocrystals were within the range of 30 to 300 nm. These materials exhibited characteristic europium ion luminescence. The europium-bearing nanocrystals and were then incorporated into the copolymer systems of MA/St and luminescence functional optical resins with high lanthanide content (50 wt%) were obtained. The combination of these particles and optical resins is facile because the diameter of Eu(DBM) 3 ·H 2 O is decreased. These copolymer-based optical resins not only possess good transparency and mechanical performance, but also exhibit an intense narrow band emission of lanthanide complexes and longer fluorescence lifetimes under UV excitation at room temperature. - Highlights: ► Novel composite optical resins with high lanthanide content have been synthesized. ► The Eu(DBM) 3 ·H 2 O nanocrystals were within the range of 30 to 300 nm. ► Fluorescent resins with high lanthanide content (50 wt%) were obtained. ► Resins exhibit intense emission of lanthanide and longer fluorescence lifetimes. ► Variety properties of Eu(DBM) 3 ·H 2 O nanocrystals were characterized.

  14. Composite Resin – A Versatile Restorative Tool | Koleoso | Nigerian ...

    African Journals Online (AJOL)

    ... the use of composite resin restorations as a treatment option in several situations where conventional aesthetic restorations such as porcelain veneers, crowns and cream-metal crown could otherwise be placed. Methods and Materials: Patients who presented with restoration aesthetic challenges over a six months period ...

  15. BACTERIAL ADHESION TO DENTAL AMALGAM AND 3 RESIN COMPOSITES

    NARCIS (Netherlands)

    SULJAK, JP; REID, G; WOOD, SM; MCCONNELL, RJ; VANDERMEI, HC; BUSSCHER, HJ

    Objectives: The ability of three oral bacteria to adhere to hydrophobic amalgam (water contact angle 60 degrees) and hydrophobic resin composites (Prisma-AP.H 56 degrees, Herculite XRV 82 degrees and Z100 89 degrees) was compared using an in vitro assay. Methods and results: Following preincubation

  16. Effect of Sandblasting on Shear Bond Strength Composite Resin Veneer

    Directory of Open Access Journals (Sweden)

    Octarina Octarina

    2013-07-01

    Full Text Available Attachment between restoration and enamel surface in indirect resin composite veneer restoration (IRCV is obtained using multi-step (MS resin cement. Recently, a one step self-adhesive dual-cured resin cement (SADRC was introduced. Objective: To determine the effect of sandblasting on shear bond strength (SBS of IRCV to enamel using MS resin cement and SADRC. Methods: Forty specimens of buccal surface of enamel human were light-cured in Solidilite chamber and were divided into two groups: IRCV without sandblasting (n=20 and with sandblasting for 10 seconds (n=20 and then bonded to enamel using MS (n=10 and SADRC (n=10, respectively. After 24h SBS of specimens were tested using a Universal Testing Machine. Data were analyzed statistically by one-way ANOVA. Results: The average SBS value of IRCV without SB and bonded with MS was 18.95+7.80MPa and MS with SB was 19.30+ SB (4.85+2.12MPa and SADRC with SB (9.57+3.45MPa(p<0.05. Conclusion: increased SBS VIRK to enamel using MS resin cement than SADRC.  

  17. Bond strength of resin composite to light activated bleached enamel

    African Journals Online (AJOL)

    2015-09-02

    Sep 2, 2015 ... After setting of the cement, a composite resin (Variolink II) block was .... do not completely duplicate the physical and chemical properties of the oral ... peroxide concentrations on the corrosion behavior and surface topography.

  18. Surface characterization of modern resin composites: a multitechnique approach.

    Science.gov (United States)

    Silikas, Nick; Kavvadia, Katerina; Eliades, George; Watts, David

    2005-04-01

    To characterize the surface properties of some modern resin composites employing a series of physicochemical methods. Specimens from three microhybrid (Palfique Estellite-PE, Z250 Filtek-ZF, Tetric Ceram-TC) and one nanofilled (Supreme Filtek-SF) conventionally photo-cured resin composites polished with Soflex disks were studied for the following properties: Surface chemical composition and degree of C=C conversion (FTIR), surface energetics (contact angles), surface texture (AFM), surface roughness (AFM, stylus profilometry) and gloss (60 degrees-, 20 degrees-angle specular gloss). Polar and non polar molecular groups were identified in all products including NH and CONH (SF, ZF, TC). SF and ZF demonstrated higher conversion than PE and TC (P 0.05) were found in critical surface tension, total work of adhesion and its polar and dispersion components, the latter being the highest in all products. AFM showed the smoothest surface texture in PE. The ranking of Sa, Sq, Ra and Rz roughness parameters was PEgloss measurements (PE, SF>ZF>TC, PTC, Pgloss differences. A positive correlation was found between Sa and Ra and a negative one between Sa and 20 degree-angle gloss.

  19. Thermal, spectral, and surface properties of LED light-polymerized bulk fill resin composites.

    Science.gov (United States)

    Pişkin, Mehmet Burçin; Atalı, Pınar Yılmaz; Figen, Aysel Kantürk

    2015-02-01

    The aim of this study was to evaluate the thermal, spectral, and surface properties of four different bulk fill materials – SureFil SDR (SDR, Dentsplay DETREY), QuixFil (QF, Dentsplay DETREY), X-tra base (XB, Voco) X-tra fil (XF, Voco) – polymerized by light-emitting diode (LED). Resin matrix, filler type, size and amount, and photoinitiator types influence the degree of conversion. LED-cured bulk fill composites achieved sufficient polymerization. Scanning electron microscope (SEM) analysis revealed different patterns of surface roughness, depending on the composite material. Bulk fill materials showed surface characteristics similar to those of nanohybrid composites. Based on the thermal analysis results, glass transition (T(g)) and initial degradation (T(i)) temperatures changed depending on the bulk fill resin composites.

  20. Antibacterial properties of composite resins incorporating silver and zinc oxide nanoparticles on Streptococcus mutans and Lactobacillus

    Directory of Open Access Journals (Sweden)

    Shahin Kasraei

    2014-05-01

    Full Text Available Objectives Recurrent caries was partly ascribed to lack of antibacterial properties in composite resin. Silver and zinc nanoparticles are considered to be broad-spectrum antibacterial agents. The aim of the present study was to evaluate the antibacterial properties of composite resins containing 1% silver and zinc-oxide nanoparticles on Streptococcus mutans and Lactobacillus. Materials and Methods Ninety discoid tablets containing 0%, 1% nano-silver and 1% nano zinc-oxide particles were prepared from flowable composite resin (n = 30. The antibacterial properties of composite resin discs were evaluated by direct contact test. Diluted solutions of Streptococcus mutans (PTCC 1683 and Lactobacillus (PTCC 1643 were prepared. 0.01 mL of each bacterial species was separately placed on the discs. The discs were transferred to liquid culture media and were incubated at 37℃ for 8 hr. 0.01 mL of each solution was cultured on blood agar and the colonies were counted. Data was analyzed with Kruskall-Wallis and Mann-Whitney U tests. Results Composites containing nano zinc-oxide particles or silver nanoparticles exhibited higher antibacterial activity against Streptococcus mutans and Lactobacillus compared to the control group (p < 0.05. The effect of zinc-oxide on Streptococcus mutans was significantly higher than that of silver (p < 0.05. There were no significant differences in the antibacterial activity against Lactobacillus between composites containing silver nanoparticles and those containing zinc-oxide nanoparticles. Conclusions Composite resins containing silver or zinc-oxide nanoparticles exhibited antibacterial activity against Streptococcus mutans and Lactobacillus.

  1. Conjugation of diisocyanate side chains to dimethacrylate reduces polymerization shrinkage and increases the hardness of composite resins.

    Science.gov (United States)

    Jan, Yih-Dean; Lee, Bor-Shiunn; Lin, Chun-Pin; Tseng, Wan-Yu

    2014-04-01

    Polymerization shrinkage is one of the main causes of dental restoration failure. This study tried to conjugate two diisocyanate side chains to dimethacrylate resins in order to reduce polymerization shrinkage and increase the hardness of composite resins. Diisocyanate, 2-hydroxyethyl methacrylate, and bisphenol A dimethacrylate were reacted in different ratios to form urethane-modified new resin matrices, and then mixed with 50 wt.% silica fillers. The viscosities of matrices, polymerization shrinkage, surface hardness, and degrees of conversion of experimental composite resins were then evaluated and compared with a non-modified control group. The viscosities of resin matrices increased with increasing diisocyanate side chain density. Polymerization shrinkage and degree of conversion, however, decreased with increasing diisocyanate side chain density. The surface hardness of all diisocyanate-modified groups was equal to or significantly higher than that of the control group. Conjugation of diisocyanate side chains to dimethacrylate represents an effective means of reducing polymerization shrinkage and increasing the surface hardness of dental composite resins. Copyright © 2012. Published by Elsevier B.V.

  2. Thermal stability relationships between PMR-15 resin and its composites

    Science.gov (United States)

    Bowles, Kenneth J.; Jayne, Douglas; Leonhardt, Todd A.; Bors, Dennis

    1993-01-01

    A study was conducted to investigate the relationship between the thermo-oxidative stability of PMR-15 matrix resin and the stability of graphite-fiber-reinforced composites that contain this resin as the matrix material. Three areas were investigated. The first was the effect of fiber/matrix interfacial bond strength on the isothermal aging weight loss of composites. By using type-A graphite fibers produced by Hercules, it was possible to study composites reinforced with fibers that were processed to receive different surface treatments. One of the fibers was untreated, a second fiber was treated by oxidation to enhance fiber/matrix bonding, and the third type of fiber was coated with an epoxy sizing. These treatments produced three significantly different interfacial bond strengths. The epoxy sizing on the third fiber was quickly oxidized from the bare fiber surfaces at 288, 316, and 343 C. The weight loss due to the removal of the sizing was constant at 1.5 percent. This initial weight loss was not observed in thermo-oxidative stability studies of composites. The PMR-15 matrix satisfactorily protected the reinforcemnt at all three temperatures.

  3. Mixed resin and carbon fibres surface treatment for preparation of carbon fibres composites with good interfacial bonding strength

    International Nuclear Information System (INIS)

    He, Hongwei; Wang, Jianlong; Li, Kaixi; Wang, Jian; Gu, Jianyu

    2010-01-01

    The objective of this work is to improve the interlaminar shear strength of composites by mixing epoxy resin and modifying carbon fibres. The effect of mixed resin matrix's structure on carbon fibres composites was studied. Anodic oxidation treatment was used to modify the surface of carbon fibres. The tensile strength of multifilament and interlaminar shear strength of composites were investigated respectively. The morphologies of untreated and treated carbon fibres were characterized by scanning electron microscope and X-ray photoelectron spectroscopy. Surface analysis indicates that the amount of carbon fibres chemisorbed oxygen-containing groups, active carbon atom, the surface roughness, and wetting ability increases after treatment. The tensile strength of carbon fibres decreased little after treatment by anodic oxidation. The results show that the treated carbon fibres composites could possess excellent interfacial properties with mixed resins, and interlaminar shear strength of the composites is up to 85.41 MPa. The mechanism of mixed resins and treated carbon fibres to improve the interfacial property of composites is obtained.

  4. In-office bleaching efficacy on stain removal from CAD/CAM and direct resin composite materials.

    Science.gov (United States)

    Alharbi, Amal; Ardu, Stefano; Bortolotto, Tissiana; Krejci, Ivo

    2018-01-01

    To evaluate the efficacy of in-office bleaching on stain removal from stained resin composite and ceramic computer-assisted design/computer-assisted manufacturing (CAD/CAM) blocks and direct resin composites. Forty disk-shaped samples were fabricated from each of nine materials: six CAD/CAM (VITABLOCS Mark II, Paradigm MZ100, Exp Vita Hybrid Ceramic, VITA ENAMIC, Exp Kerr, and LAVA Ultimate) and three direct resin composites (Filtek Supreme, Venus Diamond, and Filtek Silorane). Samples were randomly divided into five groups (n = 8), each stained with a particular staining solution. Using a calibrated spectrophotometer and a black background, L*a*b* values were assessed before and after 120 days of staining. Samples were subjected to in-office bleaching using 40% hydrogen peroxide gel for one hour. At subsequent assessment, color change (ΔE) was calculated as the difference between L*a*b* values. Both ANOVA and the Duncan test were used to identify differences between groups (α = 0.05). Bleaching resulted in significant differences in ΔE values for all materials (P Bleaching efficacy was highly influenced by material composition and staining solution. Residual color values after bleaching for ceramic and hybrid ceramics ranged from -0.49 to 2.35, within the clinically acceptable maximum of 3.3. Values after bleaching for resin-based CAD/CAM ranged from -0.7 to 7.08 while direct resin composites values ranged from -1.47 to 25.13. Coffee left the greatest residual color on all materials. Based on material nature, 40% hydrogen peroxide bleaching can remove staining. The new resin-based CAD/CAM blocks showed promising results in terms of color stability. Bleaching using 40% hydrogen peroxide can be an effective method to remove stains from dental restorations. In this way, restoration replacement as a result of discoloration may no longer be necessary. © 2017 Wiley Periodicals, Inc.

  5. Clinical performance of bulk-fill and conventional resin composite restorations in posterior teeth: a systematic review and meta-analysis.

    Science.gov (United States)

    Veloso, Sirley Raiane Mamede; Lemos, Cleidiel Aparecido Araújo; de Moraes, Sandra Lúcia Dantas; do Egito Vasconcelos, Belmiro Cavalcanti; Pellizzer, Eduardo Piza; de Melo Monteiro, Gabriela Queiroz

    2018-03-28

    The purpose of this systematic review was to compare the clinical performance of bulk-fill resin composites with conventional resin composites used for direct restorations of posterior teeth. This review followed the PRISMA statement. This review was registered at PROSPERO (registration number CRD42016053436). A search of the scientific literature was performed by two independent reviewers using the PubMed/MEDLINE, Embase, The Cochrane Library, and Web of Science databases from commencement until January 2018. The research question was "Do bulk-fill resin composites have a clinical performance comparable to conventional resin composites in posterior restorations?" Only studies evaluating class I and II direct restorations in permanent teeth with a follow-up period of at least 1 year were included. The RevMan 5 program was used for meta-analysis, calculating the relative risk (RR) and 95% confidence interval (CI) of the dichotomous outcome (restoration failure or success). Ten articles were selected, comprising 941 analyzed restorations. The mean follow-up period was 33.6 months (12-72 months). No statistically significant differences in the failure rate were observed between conventional and base/flowable bulk-fill resin composites (p = 0.31; RR 1.49; 95% CI 0.69-3.25) or full-body/sculptable bulk-fill resin composites (p = 0.12; RR 1.89; 95% CI 0.84-4.24). The present systematic review and meta-analysis indicate similar clinical performances of bulk-fill and conventional resin composites over a follow-up period of 12 to 72 months. Based on the results of this study, the bulk-fill resin composites could be an alternative for direct restorations in posterior teeth. However, clinical trials of longer duration are required.

  6. Evaluation of three different decontamination techniques on biofilm formation, and on physical and chemical properties of resin composites.

    Science.gov (United States)

    André, Carolina Bosso; Dos Santos, Andressa; Pfeifer, Carmem Silvia; Giannini, Marcelo; Girotto, Emerson Marcelo; Ferracane, Jack Liborio

    2018-04-01

    This study evaluated three different sterilization/disinfection techniques for resin composites on bacterial growth and surface modification after decontamination. Two resin composites were sterilized/disinfected with three different techniques: UV light, 1% chloramine T, and 70% ethanol. Four different times were used for each technique to determine the shortest time that the solution or UV light was effective. The influence of sterilization/disinfection technique on bacterial growth was evaluated by analyzing the metabolic activity, using the AlamarBlue™ assay, bacterial viability, and SEM images from biofilms of Streptococcus mutans. The surface change, after the process, was analyzed with ATR/FTIR and SEM images. The solutions used for decontamination (1% chloramine-T and 70% ethanol) were analyzed with 1 H-NMR to identify any resin compounds leached during the process. One minute of decontamination was efficient for all three methods tested. Chloramine-T increased the surface porosity on resin composites, no changes were observed for UV light and 70% ethanol, however, 1 H-NMR identified leached monomers only when 70% ethanol was used. No chemical change of the materials was found under ATR/FTIR analyses after the decontamination process. Chloramine-T, with no previous wash, increased the bacterial viability for both resin composites and increased the bacterial metabolism for the resin composite without fluoride. UV light had no interference on the resin composites properties tested using 1 min of exposure compared to the other decontamination methods. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 945-953, 2018. © 2017 Wiley Periodicals, Inc.

  7. Polymerization shrinkage kinetics and shrinkage-stress in dental resin-composites.

    Science.gov (United States)

    Al Sunbul, Hanan; Silikas, Nick; Watts, David C

    2016-08-01

    To investigate a set of resin-composites and the effect of their composition on polymerization shrinkage strain and strain kinetics, shrinkage stress and the apparent elastic modulus. Eighteen commercially available resin-composites were investigated. Three specimens (n=3) were made per material and light-cured with an LED unit (1200mW/cm(2)) for 20s. The bonded-disk method was used to measure the shrinkage strain and Bioman shrinkage stress instrument was used to measure shrinkage stress. The shrinkage strain kinetics at 23°C was monitored for 60min. Maximum strain and stress was evaluated at 60min. The shrinkage strain rate was calculated using numerical differentiation. The shrinkage strain values ranged from 1.83 (0.09) % for Tetric Evoceram (TEC) to 4.68 (0.04) % for Beautifil flow plus (BFP). The shrinkage strain rate ranged from 0.11 (0.01%s(-1)) for Gaenial posterior (GA-P) to 0.59 (0.07) %s(-1) for BFP. Shrinkage stress values ranged from 3.94 (0.40)MPa for TET to 10.45 (0.41)MPa for BFP. The apparent elastic modulus ranged from 153.56 (18.7)MPa for Ever X posterior (EVX) to 277.34 (25.5) MPa for Grandio SO heavy flow (GSO). The nature of the monomer system determines the amount of the bulk contraction that occurs during polymerization and the resultant stress. Higher values of shrinkage strain and stress were demonstrated by the investigated flowable materials. The bulk-fill materials showed comparable result when compared to the traditional resin-composites. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Failure in a composite resin-dentin adhesive bond

    Energy Technology Data Exchange (ETDEWEB)

    Rezgui, B. (Dept. de Genie Mecanique, Ecole Nationale d' Ingenieurs de Monastir, Monastir (Tunisia)); Abdennagi, H. (Dept. de Genie Mecanique, Ecole Nationale d' Ingenieurs de Monastir, Monastir (Tunisia)); Sahtout, S. (Dept. de Genie Mecanique, Ecole Nationale d' Ingenieurs de Monastir, Monastir (Tunisia) Dept. d' Odontologie, Faculte de Chirurgie Dentaire de Monastir (Tunisia)); Belkhir, M.S. (Dept. de Genie Mecanique, Ecole Nationale d' Ingenieurs de Monastir, Monastir (Tunisia) Dept. d' Odontologie, Faculte de Chirurgie Dentaire de Monastir (Tunisia))

    1993-11-01

    Composites are drawing more and more attention as preferred materials for teeth restoration. The success of teeth restoration has been generally limited by the Composite Resin-Dentin bond strength. A testing device has been developped to allow a satisfactory testing method for evaluating bonding strength in tension and shear, which led to reproducible results. A comparaison between different bond systems has shown no significant difference in the tensile and the shear strength as well as in the fracture behavior. Moreover, results showed difference between tensile and shear strength, when considering one same bond system. Failure mode examination turned out to be, either cohesive (composite rupture), or adhesive (interface rupture) or both (mixed rupture). (orig.).

  9. Effect of saliva and blood contamination after etching upon the shear bond strength between composite resin and enamel

    Science.gov (United States)

    Armadi, A. S.; Usman, M.; Suprastiwi, E.

    2017-08-01

    The aim of this study was to find out the surface roughness of composite resin veneer after brushing. In this study, 24 specimens of composite resin veneer are divided into three subgroups: brushed without toothpaste, brushed with non-herbal toothpaste, and brushed with herbal toothpaste. Brushing was performed for one set of 5,000 strokes and continued for a second set of 5,000 strokes. Roughness of composite resin veneer was determined using a Surface Roughness Tester. The results were statistically analyzed using Kruskal-Wallis nonparametric test and Post Hoc Mann-Whitney. The results indicate that the highest difference among the Ra values occurred within the subgroup that was brushed with the herbal toothpaste. In conclusion, the herbal toothpaste produced a rougher surface on composite resin veneer compared to non-herbal toothpaste.

  10. Surface Modified Characteristics of the Tetracalcium Phosphate as Light-Cured Composite Resin Fillers

    Directory of Open Access Journals (Sweden)

    Wen-Cheng Chen

    2014-01-01

    Full Text Available The objectives of this study are to characterize the properties of light-cured composite resins that are reinforced with whisker surface-modified particles of tetracalcium phosphate (TTCP and to investigate the influence of thermal cycling on the reinforced composites properties. The characteristics of ultimate diametral tensile strength (DTS, moduli, pH values, and fracture surfaces of the samples with different amounts of surface-modified TTCP (30%–60% were determined before and after thermal cycling between 5°C and 55°C in deionized water for 600 cycles. The trends of all groups were ductile prior to thermal cycling and the moduli of all groups increased after thermal cycling. The ductile property of the control group without filler was not significantly affected. Larger amounts of fillers caused the particles to aggregate, subsequently decreasing the resin’s ability to disperse external forces and leading to brittleness after thermal cycling. Therefore, the trend of composite resins with larger amounts of filler would become more brittle and exhibited higher moduli after thermal cycling. This developed composite resin with surface modified-TTCP fillers has the potential to be successful dental restorative materials.

  11. Candida albicans adherence to resin-composite restorative dental material: influence of whole human saliva.

    Science.gov (United States)

    Maza, José Luis; Elguezabal, Natalia; Prado, Carlota; Ellacuría, Joseba; Soler, Iñaki; Pontón, José

    2002-11-01

    Attachment of Candida albicans to oral surfaces is believed to be a critical event in the colonization of the oral cavity and in the development of oral diseases such as Candida-associated denture stomatitis. Although there is considerable information about the adhesion of C albicans to buccal epithelial cells and prosthetic materials, there is very little information about the adhesion of C albicans to composite restorative materials. The purpose of this study was to investigate the degree of adhesion of C albicans to a resin-composite restorative material (Herculite). The adhesion of 2 strains of C albicans, a germinative and a germ tube-deficient mutant, was studied by a visual method after incubating the fungus and the resin with and without human whole saliva. In absence of saliva, the adhesion of the C albicans germinative isolate to the resin showed an increase in parallel with the germination, reaching a maximum at the end of the experiment (120 minutes). However, no significant differences were observed in the adhesion of the agerminative mutant during the period of time studied. In the presence of saliva, the adhesion of both isolates to the resin was significantly lowered. Germination and the presence of human whole saliva are important factors in the adhesion of C albicans to the resin-composite restorative material Herculite.

  12. Changes in opalescence and fluorescence properties of resin composites after accelerated aging.

    Science.gov (United States)

    Lee, Yong-Keun; Lu, Huan; Powers, John M

    2006-07-01

    Opalescence and fluorescence properties and the correlated translucency and masking effect of resin composites may change after aging. The objective of this study was to determine the changes in opalescence and fluorescence properties of resin composites after accelerated aging for 150 kJ/m2. Changes in translucency and masking effect were also determined. Color and spectral distribution of seven resin composites (A2 shade, 1-mm thick) were measured in the reflectance and transmittance modes under ultraviolet light (UV)-included and excluded conditions. Opalescence parameter (OP) was calculated as the difference in yellow-blue (Deltab*) and red-green (Deltaa*) coordinates between the reflected and transmitted colors under UV-included and excluded conditions. For the fluorescence evaluation, color differences (FL-Ref and FL-Trans) by the inclusion or exclusion of the UV-component of the standard illuminant D65 in the reflectance and transmittance modes were calculated. Under UV-included and excluded conditions, the translucency parameter (TP) was calculated, and the masking effect (ME) was calculated as the color difference between a specimen over a black tile and black tile itself. Repeated-measures 2-way analysis of variance at the significance level of 0.05 was performed for the values before and after aging. OP values in UV-included and excluded conditions did not change significantly after aging. FL-Ref and FL-Trans, TP values and ME values in UV-included and excluded conditions changed significantly after aging (pOpalescence of resin composites did not change but fluorescence was not detected after accelerated aging for 150 kJ/m2. Translucency and masking effect changed significantly after aging.

  13. Color Stability Assessment of Two Different Composite Resins with Variable Immersion Time Using Various Beverages: An In vitro Study.

    Science.gov (United States)

    Kumar, M Senthil; Ajay, R; Miskeen Sahib, S A; Chittrarasu, M; Navarasu, M; Ragavendran, N; Burhanuddin Mohammed, Omar Farooq

    2017-11-01

    The aim of the study was to evaluate the difference in the color of microhybrid (MH) and nanofilled (NF) composite resins after 24 and 48 h in beverages such as red wine (RW), Coca-Cola, and distilled water. The specific objective of this study was to investigate the cumulative effect of the colorant solutions on the dental composites. MH and NF composite resins (A2 shade) were used in this current study. Sixty disk-shaped material specimens (10 mm in diameter × 2 mm in thickness) were prepared using a fiber mold (ring), with the desired dimensions. The specimen surfaces were polished using super-snap polishing system. Sixty specimens were divided into two groups of 30 each (Group I: MH resin composite; Group II: NF resin composite). Both the groups divided into six subgroups (Subgroup I: RW for 24 h [RW-24]; Subgroup II: RW for 48 h; Subgroup III: Coca-Cola for 24 h [CC-24]; Subgroup IV: Coca-Cola for 48 h [CC-48]; Subgroup V: Distilled water for 24 h [DW-24]; Subgroup VI: Distilled water for 48 h [DW-48]). All the samples were immersed in respective drinks for a period of 24 h, and color differences were measured using ultraviolet spectrophotometer. Once again, all the samples were immersed for another 24 h in the same drinks. After 48 h, the color change of the samples was measured. Measurements were made according to the CIE L × a × b × color space relative to the CIE standard illuminant D65. The color changes of the specimens were evaluated using the following formula: Statistical analysis was performed. The data were analyzed using the one-way ANOVA and t -test at a significance level of 0.05. Color stability of MH composite resin was found to be inferior than the NF resin composite irrespective of immersion medium and time. In RW, the color change observed was maximum for both composite resins followed by Coca-Cola. Immersing the resin composites in distilled water for 24 and 48 h had negligible color change. A 48-h immersion of both composite resins in

  14. Bonding of Glass Ceramic and Indirect Composite to Non-aged and Aged Resin Composite

    NARCIS (Netherlands)

    Gresnigt, Marco; Ozcan, Mutlu; Muis, Maarten; Kalk, Warner

    2012-01-01

    Purpose: Since adhesion of the restorative materials to pre-polymerized or aged resin composites presents a challenge to the clinicians, existing restorations are often removed and remade prior to cementation of fixed dental prostheses (FDPs). This study evaluated bond strength of non-aged and aged

  15. Composite resin reinforced with pre-tensioned fibers: a three-dimensional finite element study on stress distribution.

    Science.gov (United States)

    Jie, Lin; Shinya, Akikazu; Lassila, Lippo V J; Vallittu, Pekka K

    2013-01-01

    Pre-tensioned construction material is utilized in engineering applications of high strength demands. The purpose of this study was to evaluate the effect of the pre-tensioning fibers of fiber-reinforced composite (FRC) using three-dimensional finite element (FE) analysis. The 3D FE models of particulate composite resin (CR), FRC and composite resin reinforced with pre-tensioned fibers (PRE-T-FRC) were constructed. The uniaxial three-point bending test was simulated using FE analysis to calculate the principal stress distribution. In the FRC and PRE-T-FRC, stresses were higher than CR, and they were located in the fiber. However, the maximum principal stress value at the composite of PRE-T-FRC was lower than the FRC and CR. Composite resin reinforced with pre-tensioned fibers was advantageous for stress distribution and lowering the stress at the composite itself. Experimental studies on physical properties of pre-tensioned FRC are encouraged to be conducted.

  16. A new methodology for fluorescence analysis of composite resins used in anterior direct restorations.

    Science.gov (United States)

    de Lima, Liliane Motta; Abreu, Jessica Dantas; Cohen-Carneiro, Flavia; Regalado, Diego Ferreira; Pontes, Danielson Guedes

    2015-01-01

    The aim of this study was to use a new methodology to evaluate the fluorescence of composite resins for direct restorations. Microhybrid (group 1, Amelogen; group 2, Opallis; group 3, Filtek Z250) and nanohybrid (group 4, Filtek Z350 XT; group 5, Brilliant NG; group 6, Evolu-X) composite resins were analyzed in this study. A prefabricated matrix was used to prepare 60 specimens of 7.0 × 3.0 mm (n = 10 per group); the composite resin discs were prepared in 2 increments (1.5 mm each) and photocured for 20 seconds. To establish a control group of natural teeth, 10 maxillary central incisor crowns were horizontally sectioned to create 10 discs of dentin and enamel tissues with the same dimensions as the composite resin specimens. The specimens were placed in a box with ultraviolet light, and photographs were taken. Aperture 3.0 software was used to quantify the central portion of the image of each specimen in shades of red (R), green (G), and blue (B) of the RGB color space. The brighter the B shade in the evaluated area of the image, the greater the fluorescence shown by the specimen. One-way analysis of variance revealed significant differences between the groups. The fluorescence achieved in group 1 was statistically similar to that of the control group and significantly different from those of the other groups (Bonferroni test). Groups 3 and 4 had the lowest fluorescence values, which were significantly different from those of the other groups. According to the results of this study, neither the size nor the amount of inorganic particles in the evaluated composite resin materials predicts if the material will exhibit good fluorescence.

  17. EFFECT OF HARDENER ON MECHANICAL PROPERTIES OF CARBON FIBRE REINFORCED PHENOLIC RESIN COMPOSITES

    Directory of Open Access Journals (Sweden)

    S. SULAIMAN

    2008-04-01

    Full Text Available In this paper the effect of hardener on mechanical properties of carbon reinforced phenolic resin composites is investigated. Carbon fibre is one of the most useful reinforcement materials in composites, its major use being the manufacture of components in the aerospace, automotive, and leisure industries. In this study, carbon fibres are hot pressed with phenolic resin with various percentages of carbon fibre and hardener contents that range from 5-15%. Composites with 15% hardener content show an increase in flexural strength, tensile strength and hardness. The ultimate tensile strength (UTS, flexural strength and hardness for 15% hardener are 411.9 MPa, 51.7 MPa and 85.4 HRR respectively.

  18. Thermal behavior of phenol-furfuryl alcohol resin/carbon nanotubes composites

    Science.gov (United States)

    Conejo, L. S.; Costa, M. L.; Oishi, S. S.; Botelho, E. C.

    2018-04-01

    Phenol-furfuryl alcohol resins (PFA) are excellent candidates to replace existing thermoset matrices used in obtaining insulating systems or carbon materials, both in its pure form and reinforced with nanoscale structures. This work had as main purpose synthesize and investigate thermal characterization of PFA resin and its nanostructured composites with different concentrations of carbon nanotubes (0, 0.1, 0.5 and 1.0 wt%). The DSC analysis was performed to estimate the specific heat (cp) of the cured samples and thermomechanical analysis to find the linear thermal expansion coefficient (α). From these results, the cp values found for the PFA system was similar to that described in the literature for the phenolic resin. The cp increased with the increase in the CNT concentration in the system up to 0.5%. The coefficient of linear thermal expansion obtained by TMA technique for PFA sample was 33.10‑6/°C which was close to the α value of phenolic resin (40 to 80.10‑6/°C).

  19. Fracture resistance of endodontically treated teeth restored with a bulkfill flowable material and a resin composite.

    Science.gov (United States)

    Isufi, Almira; Plotino, Gianluca; Grande, Nicola Maria; Ioppolo, Pietro; Testarelli, Luca; Bedini, Rossella; Al-Sudani, Dina; Gambarini, Gianluca

    2016-01-01

    To determine and compare the fracture resistance of endodontically treated teeth restored with a bulk fill flowable material (SDR) and a traditional resin composite. Thirty maxillary and 30 mandibular first molars were selected based on similar dimensions. After cleaning, shaping and filling of the root canals and adhesive procedures, specimens were assigned to 3 subgroups for each tooth type (n=10): Group A: control group, including intact teeth; Group B: access cavities were restored with a traditional resin composite (EsthetX; Dentsply-Italy, Rome, Italy); Group C: access cavities were restored with a bulk fill flowable composite (SDR; Dentsply-Italy), except 1.5 mm layer of the occlusal surface that was restored with the same resin composite as Group B. The specimens were subjected to compressive force in a material static-testing machine until fracture occurred, the maximum fracture load of the specimens was measured (N) and the type of fracture was recorded as favorable or unfavorable. Data were statistically analyzed with one-way analysis of variance (ANOVA) and Bonferroni tests (Pcomposite and with a bulk fill flowable composite (SDR) was similar in both maxillary and mandibular molars and showed no significant decrease in fracture resistance compared to intact specimens. No significant difference was observed in the mechanical fracture resistance of endodontically treated molars restored with traditional resin composite restorations compared to bulk fill flowable composite restorations.

  20. Kinetics and equilibrium studies for sorption of Cu (II) and Cr (VI) ions onto polymeric composite resins

    International Nuclear Information System (INIS)

    El-Zahhhar, A.A.; Abdel-Aziz, H.M.; Siyam, T.

    2005-01-01

    The sorption behavior of Cu (II) and Cr (VI) ions from aqueous solutions was studied using polymeric composite resins. Batch sorption experiments were performed as a function of hydrogen ion concentration, complexing agent concentration, resin weight and ionic strength. Kinetic parameters as a function of initial ion concentration were determined to predict the sorption behavior of Cu (II) and Cr (VI) onto polymeric composite resins. The equilibrium data could be fitted by the frendlich adsorption isotherm equation

  1. Fluorine analysis of human dentin surrounding resin composite after fluoride application by μ-PIGE/PIXE analysis

    Science.gov (United States)

    Okuyama, Katsushi; Komatsu, Hisanori; Yamamoto, Hiroko; Pereira, Patricia N. R.; Bedran-Russo, Ana K.; Nomachi, Masaharu; Sato, Takahiro; Sano, Hidehiko

    2011-10-01

    The use of fluoride for the prevention of caries is based on the transformation of hydroxylapatite to fluoroapatite in the presence of fluoride ions, thereby strengthening tooth structure. Adhesion of dentin and resin composite (tooth-colored restoration material) requires a dentin bonding system, since resin composite is not able to adhere to dentin directly. Demineralization of dentin by acid etching is an important step in the dentin bonding system, however, demineralization also introduces weaknesses in tooth structure. If the demineralized dentin could be strengthened by the application of fluoride, then the dentin-resin composite bond strength might also improve. To test this hypothesis, the present study evaluated the influence of fluoride applications on the strength of the dentin-resin composite bond by (1) tensile strength testing analyses, (2) SEM analyses of tooth structure, and (3) detection of calcium (Ca) and fluorine (F) distribution patterns by micro proton-induced X-ray emission (μ-PIXE) and micro proton-induced gamma-ray emission (μ-PIGE) analyses conducted at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) at the Takasaki Advanced Radiation Research Institute (TARRI). In this study, the dentin in extracted human molars was exposed by grinding and the dentin was etched with 35% phosphoric acid. Fluoride was applied at two concentrations, 0.022% (100 ppm F) and 2.21% (10,000 ppm F) NaF solution, for two time periods, 30 and 60 s, prior to bonding the resin composite with the treated dentin. Controls were prepared in the same manner, but without the fluoride application. Bond strength was measured with a micro-tensile testing unit, and the fluorine and calcium distributions at the interface between dentin and resin composite were detected by μ-PIGE and μ-PIXE analysis, respectively. Results indicate that the 10,000 ppm F applications resulted in higher bond strengths than observed in either the 100 ppm F applications or

  2. Fluorine analysis of human dentin surrounding resin composite after fluoride application by μ-PIGE/PIXE analysis

    International Nuclear Information System (INIS)

    Okuyama, Katsushi; Komatsu, Hisanori; Yamamoto, Hiroko; Pereira, Patricia N.R.; Bedran-Russo, Ana K.; Nomachi, Masaharu; Sato, Takahiro; Sano, Hidehiko

    2011-01-01

    The use of fluoride for the prevention of caries is based on the transformation of hydroxylapatite to fluoroapatite in the presence of fluoride ions, thereby strengthening tooth structure. Adhesion of dentin and resin composite (tooth-colored restoration material) requires a dentin bonding system, since resin composite is not able to adhere to dentin directly. Demineralization of dentin by acid etching is an important step in the dentin bonding system, however, demineralization also introduces weaknesses in tooth structure. If the demineralized dentin could be strengthened by the application of fluoride, then the dentin-resin composite bond strength might also improve. To test this hypothesis, the present study evaluated the influence of fluoride applications on the strength of the dentin-resin composite bond by (1) tensile strength testing analyses, (2) SEM analyses of tooth structure, and (3) detection of calcium (Ca) and fluorine (F) distribution patterns by micro proton-induced X-ray emission (μ-PIXE) and micro proton-induced gamma-ray emission (μ-PIGE) analyses conducted at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) at the Takasaki Advanced Radiation Research Institute (TARRI). In this study, the dentin in extracted human molars was exposed by grinding and the dentin was etched with 35% phosphoric acid. Fluoride was applied at two concentrations, 0.022% (100 ppm F) and 2.21% (10,000 ppm F) NaF solution, for two time periods, 30 and 60 s, prior to bonding the resin composite with the treated dentin. Controls were prepared in the same manner, but without the fluoride application. Bond strength was measured with a micro-tensile testing unit, and the fluorine and calcium distributions at the interface between dentin and resin composite were detected by μ-PIGE and μ-PIXE analysis, respectively. Results indicate that the 10,000 ppm F applications resulted in higher bond strengths than observed in either the 100 ppm F applications or

  3. Fluorine analysis of human dentin surrounding resin composite after fluoride application by {mu}-PIGE/PIXE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Okuyama, Katsushi, E-mail: katsu@den.hokudai.ac.jp [Graduate School of Dental Medicine, Hokkaido University, Department of Restorative Dentistry, Kita-13, Nishi-7, Kita-ku, Hokkaido, Sapporo 060-8586 (Japan) and School of Dentistry, University of North Carolina, Department of Operative Dentistry, 302 Brauer, CB 7450, Chapel Hill, NC 27599-7450 (United States); Komatsu, Hisanori [Graduate School of Dental Medicine, Hokkaido University, Department of Restorative Dentistry, Kita-13, Nishi-7, Kita-ku, Hokkaido, Sapporo 060-8586 (Japan); Yamamoto, Hiroko [Graduate School of Dentistry, Osaka University, 1-8 Yamada-Oka, Osaka, Suita 565-0871 (Japan); Pereira, Patricia N.R. [School of Dentistry, University of North Carolina, Department of Operative Dentistry, 302 Brauer, CB 7450, Chapel Hill, NC 27599-7450 (United States); Bedran-Russo, Ana K. [University of Illinois at Chicago, College of Dentistry, Department of Restorative Dentistry, 801 S. Paulina St., Chicago, IL 60612 (United States); Nomachi, Masaharu [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Osaka, Toyonaka 560-0043 (Japan); Sato, Takahiro [TARRI, JAEA, Advanced Radiation Technology, 1233 Watanuki-machi, Gunma, Takasaki 370-1292 (Japan); Sano, Hidehiko [Graduate School of Dental Medicine, Hokkaido University, Department of Restorative Dentistry, Kita-13, Nishi-7, Kita-ku, Hokkaido, Sapporo 060-8586 (Japan)

    2011-10-15

    The use of fluoride for the prevention of caries is based on the transformation of hydroxylapatite to fluoroapatite in the presence of fluoride ions, thereby strengthening tooth structure. Adhesion of dentin and resin composite (tooth-colored restoration material) requires a dentin bonding system, since resin composite is not able to adhere to dentin directly. Demineralization of dentin by acid etching is an important step in the dentin bonding system, however, demineralization also introduces weaknesses in tooth structure. If the demineralized dentin could be strengthened by the application of fluoride, then the dentin-resin composite bond strength might also improve. To test this hypothesis, the present study evaluated the influence of fluoride applications on the strength of the dentin-resin composite bond by (1) tensile strength testing analyses, (2) SEM analyses of tooth structure, and (3) detection of calcium (Ca) and fluorine (F) distribution patterns by micro proton-induced X-ray emission ({mu}-PIXE) and micro proton-induced gamma-ray emission ({mu}-PIGE) analyses conducted at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) at the Takasaki Advanced Radiation Research Institute (TARRI). In this study, the dentin in extracted human molars was exposed by grinding and the dentin was etched with 35% phosphoric acid. Fluoride was applied at two concentrations, 0.022% (100 ppm F) and 2.21% (10,000 ppm F) NaF solution, for two time periods, 30 and 60 s, prior to bonding the resin composite with the treated dentin. Controls were prepared in the same manner, but without the fluoride application. Bond strength was measured with a micro-tensile testing unit, and the fluorine and calcium distributions at the interface between dentin and resin composite were detected by {mu}-PIGE and {mu}-PIXE analysis, respectively. Results indicate that the 10,000 ppm F applications resulted in higher bond strengths than observed in either the 100 ppm F

  4. Influence of irradiance on Knoop hardness, degree of conversion, and polymerization shrinkage of nanofilled and microhybrid composite resins.

    Science.gov (United States)

    Fugolin, Ana Paula Piovezan; Correr-Sobrinho, Lourenço; Correr, Américo Bortolazzo; Sinhoreti, Mário Alexandre Coelho; Guiraldo, Ricardo Danil; Consani, Simonides

    2016-01-01

    The purpose of this study was to investigate the influence of the irradiance emitted by a light-curing unit on microhardness, degree of conversion (DC), and gaps resulting from shrinkage of 2 dental composite resins. Cylinders of nanofilled and microhybrid composites were fabricated and light cured. After 24 hours, the tops and bottoms of the specimens were evaluated via indentation testing and Fourier transform infrared spectroscopy to determine Knoop hardness number (KHN) and DC, respectively. Gap width (representing polymerization shrinkage) was measured under a scanning electron microscope. The nanofilled composite specimens presented significantly greater KHNs than did the microhybrid specimens (P composite resin exhibited significantly greater DC and gap width than the nanofilled material (P composite resins.

  5. Effect of a surface sealant on the color stability of composite resins after immersion in staining solution.

    Science.gov (United States)

    Pedroso, Lauana Borges; Barreto, Luma Franciélle Cabreira; Miotti, Leonardo Lamberti; Nicoloso, Gabriel Ferreira; Durand, Leticia Brandão

    2016-01-01

    This study evaluated the influence of surface sealants on the color stability of 2 different composite resins after immersion in coffee. Four groups were created (n = 10): microhybrid composite, microhybrid with surface sealant, nanofilled composite, and nanofilled composite with surface sealant. Half of the specimens of each group were immersed in distilled water and half were immersed in coffee for 48 hours. Color was measured before and after immersion. Groups with surface sealants presented less color variation when compared with the groups without surface sealants. The nanofilled resin specimens presented the greatest color variation within the groups without sealant. The surface sealant positively influenced the color stability of composite resin specimens immersed in coffee. When surface sealant was not applied, the microhybrid specimens had better color stability than the nanofilled.

  6. Bond strength of resin composite to differently conditioned amalgam

    NARCIS (Netherlands)

    Ozcan, M; Vallittu, PK; Huysmans, MC; Kalk, W; Vahlberg, T

    Bulk fracture of teeth, where a part of the amalgam restoration and/or the cusp is fractured, is a common clinical problem. The aim of this study was to evaluate the effect of different surface conditioning methods on the shear bond strength of a hybrid resin composite to fresh amalgam. Amalgams (N

  7. Effect of different light curing units on Knoop hardness and temperature of resin composite

    OpenAIRE

    Guiraldo Ricardo; Consani Simonides; Xediek Consani Rafael; Mendes Wilson; Lympius Thais; Coelho Sinhoreti Mario

    2009-01-01

    Aim: To evaluate the influence of quartz tungsten halogen and plasma arc curing (PAC) lights on Knoop hardness and change in polymerization temperature of resin composite. Materials and Methods: Filtek Z250 and Esthet X composites were used in the shade A3. The temperature increase was registered with Type-k thermocouple connected to a digital thermometer (Iopetherm 46). A self-cured polymerized acrylic resin base was built in order to guide the thermocouple and to support the dentin disk ...

  8. Effect of zirconium nanoparticles on the mechanical properties of light-cured resin based dental composites

    International Nuclear Information System (INIS)

    Afza, N.; Anis, I.; Aslam, M.; Shah, M.R.; Hussain, M.T.; Bokhari, T.H.; Hussain, A.; Safdar, M.

    2012-01-01

    The aim of this study was to evaluate the mechanical properties of conventional composite resins (Solare-P) and the modified composite resin having mixed with zirconium nanoparticles. The composite resins are used to replace the missing tooth structure and improve esthetics. In this study, the composite was filled with increments in a mould which was 4 mm in depth and 3 mm in diameter. After filling, it was polymerized with halogen light curing unit for 20 seconds for each increment. In other experiments, the composite was mixed with zirconium nanoparticles and filled in the moulds with increments and polymerized for 20 seconds with halogen light curing unit for each increment. After keeping the moulds at 37 deg. C for 24 hours their mechanical properties including compressive force, %age elongation, compressive strength and hardness were evaluated. It was seen that by adding zirconium nanoparticles, compressive force, %age elongation, compressive strength and hardness increased significantly. Thus it was concluded that the new materials are better than the conventional compomers. (author)

  9. Anterior makeover on fractured teeth by simple composite resin restoration

    Directory of Open Access Journals (Sweden)

    Eric Priyo Prasetyo

    2011-09-01

    Full Text Available Background: In daily practice dentists usually treat tooth fractures with more invasive treatments such as crown, veneer and bridges which preparation require more tooth structure removal. While currently there is trend toward minimal invasive dentistry which conserves more tooth structure. This is enhanced with the vast supply of dental materials and equipment in the market, including restorative materials. Provided with these supporting materials and equipment and greater patient’s demand for esthetic treatment, dentists must aware of the esthetics and basic principle of conserving tooth which should retain tooth longevity. Purpose: This article showed that a simple and less invasive composite resin restoration can successfully restore anterior esthetic and function of fractured teeth which generally treated with more invasive treatment options. Case: A 19 year-old female patient came with fracture on 21 and 22. This patient had a previous history of dental trauma about nine years before and was brought to a local dentist for debridement and was given analgesic, the involved teeth were not given any restorative treatment. Case management: The fractured 21 and 22 were conventionally restored with simple composite resin restoration. Conclusion: Fracture anterior teeth would certainly disturbs patient’s appearance, but these teeth could be managed conservatively and economically by simple composite resin restoration.Latar belakang: Dalam praktek sehari-hari pada umumnya dokter gigi merawat fraktur dengan restorasi invasif seperti mahkota, veneer dan jembatan yang semuanya memerlukan pengambilan jaringan gigi lebih banyak, sedangkan saat ini trend perawatan gigi lebih menuju kearah invasif minimal yang mempertahankan jaringan gigi sebanyak mungkin. Keadaan ini ditunjang oleh tersedianya berbagai macam bahan dan peralatan kedokteran gigi di pasaran, termasuk bahan restorasi. Dengan tersedianya bahan dan peralatan yang mendukung serta tingginya

  10. The effect of home bleaching agents on the surface roughness of five different composite resins: A SEM evaluation.

    Science.gov (United States)

    Cengiz, Esra; Kurtulmus-Yilmaz, Sevcan; Ulusoy, Nuran; Deniz, Sule Tugba; Yuksel-Devrim, Ece

    2016-05-01

    The aim of this study was to investigate the effect of hydrogen peroxide (HP) and carbamide peroxide (CP) on the surface roughness of five different composite resins using profilometer and scanning electron microscope (SEM). Thirty-six specimens (1 mm thick, 10 mm in diameter) of five composite resins were fabricated. Each composite group was equally divided into three subgroups as control, CP and HP. In control group, specimens were stored in daily refreshed distilled water during the 14-day testing period. In other groups, 10% HP (Opalescence Treswhite) and 10% CP (Opalescence PF) were applied and surface roughness values (Ra) of each specimen were measured with a profilometer at the end of 14 days. Additionally, SEM analysis was performed to evaluate the surface deformations of composite resins. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Ra values of composite groups exposed to bleaching agents were statistically higher than control group (p composite group while SEM micrographs showed higher surface alterations at HP group compared to CP. Among the composite resins tested, Ceram-X Mono revealed the lowest Ra values after CP and HP applications as seen at SEM images. Home bleaching agents increased the surface roughness of all composites. Except CP applied Ceram-X mono specimens, Ra values of all composite resins evaluated in this study exceeded the critical limit of 0.2 μm. Ceram-X mono was the least affected composite material after bleaching application. SCANNING 38:277-283, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  11. Effect of universal adhesive etching modes on bond strength to dual-polymerizing composite resins.

    Science.gov (United States)

    Michaud, Pierre-Luc; Brown, Matthew

    2018-04-01

    Information is lacking as to the effect on bond strength of the etching modes of universal adhesives when they are used to bond dual-polymerizing composite resins to dentin. The purpose of this in vitro study was to investigate the bonding of dual-polymerizing foundation composite resins to dentin when universal bonding agents are used in self-etch or etch-and-rinse modes. Sixty caries-free, extracted third molar teeth were sectioned transversely in the apical third of the crown and allocated to 12 groups (n=5). Three different bonding agents (Scotchbond Universal, OptiBond XTR, All-Bond Universal) were used to bond 2 different dual-polymerizing composite resins (CompCore AF or CoreFlo DC) to dentin, using 2 different etching approaches (etch-and-rinse or self-etch). The specimens were sectioned into sticks (1×1×8 mm) with a precision saw. The bond strength of the specimens was tested under microtensile force at a crosshead speed of 0.5 mm/min. The data were analyzed using a 3-way ANOVA, a Games-Howell post hoc comparisons model, and Student t tests with Bonferroni corrections (α=.05). In the overall model, the composite resin used had no effect on bond strength (P=.830). The etching protocol by itself also did not have a significant effect (P=.059), although a trend was present. The bonding agent, however, did have an effect (Pcomposite resins to dentin, no single etching protocol is better than another. Depending on which bonding agent is being used, one etching mode may perform better. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  12. In vitro study of Streptococcus mutans adhesion on composite resin coated with three surface sealants

    Directory of Open Access Journals (Sweden)

    Da Hye Kim

    2017-02-01

    Full Text Available Objectives Although the coating of surface sealants to dental composite resin may potentially reduce bacterial adhesion, there seems to be little information regarding this issue. This preliminary in vitro study investigated the adhesion of Streptococcus mutans (S. mutans on the dental composite resins coated with three commercial surface sealants. Materials and Methods Composite resin (Filtek Z250 discs (8 mm in diameter, 1 mm in thickness were fabricated in a mold covered with a Mylar strip (control. In group PoGo, the surfaces were polished with PoGo. In groups PS, OG, and FP, the surfaces polished with PoGo were coated with the corresponding surface sealants (PermaSeal, PS; OptiGuard, OG; Fortify Plus, FP. The surfaces of the materials and S. mutans cells were characterized by various methods. S. mutans adhesion to the surfaces was quantitatively evaluated using flow cytometry (n = 9. Results Group OG achieved the lowest water contact angle among all groups tested (p 0.05 or significantly lower (group OG, p < 0.001 bacterial adhesion when compared with the control group. Conclusions The application of the surface sealants significantly reduced S. mutans adhesion to the composite resin polished with the PoGo.

  13. Unsaturated polyester resin composition curable with ionizing radiations

    International Nuclear Information System (INIS)

    Maruyama, Tsutomu; Murata, Koichiro.

    1971-01-01

    An unsaturated polyester resin composition curable with ionizing radiations and excellent in weather resistance is provided. The composition is obtained by reacting 10-12 moles of a polyhydric alcohol (e.g. ethylene glycol) with 10 moles of an acid mixture (25.45% by mole of endo-cis-bicyclo (2,2,1)-5-heptene-2-3-dicarboxylic acid (A), 20-40% of unsaturated dibasic acid and 15-55% of saturated dibasic acid) so that the acid value reaches 4-11. The composition is useful as coating, laminating and molding materials. As a coating material it is excellent in surface hardening property. The ionizing radiation used is preferably β-, α-rays or electron beams. In one example, and unsaturated polyester was prepared by reacting 3 moles of fumaric acid, 2 moles of phthalic anhydride, 3 moles of adipic acid 3, moles of (A), 10 moles of neopentyl glycol and 1 mole of trimethylolpropane. The resin was dissolved into a mixture of styrene, methyl methacrylate and butyl acrylate (50:8:42) and incorporated with titanium white. An ABS plate was coated with the enamel thus obtained and irradiated with electron beams (12 Mrad). In exposure test at 60 0 C, luster of the film was 92 before exposure and 83 after 30 months. In a comparative run in which (A) was not used, luster of the film decreased from 90 to 45 in 30 months. (Sakaichi, S.)

  14. Processing and Properties of Vacuum Assisted Resin Transfer Molded Phenylethynyl Terminated Imide Composites

    Science.gov (United States)

    Cano, Roberto J.; Ghose, Sayata; Watson, Kent A.; Chunchu, Prasad B.; Jensen, Brian J.; Connell, John W.

    2012-01-01

    Polyimide composites are very attractive for applications that require a high strength to weight ratio and thermal stability. Recent work at NASA Langley Research Center (LaRC) has concentrated on developing new polyimide resin systems that can be processed without the use of an autoclave for advanced aerospace applications. Due to their low melt viscosities and long melt stability, certain phenylethynyl terminated imides (PETI) can be processed into composites using high temperature vacuum assisted resin transfer molding (HT-VARTM). VARTM has shown the potential to reduce the manufacturing cost of composite structures. In the current study, two PETI resins, LARC(Trademark) PETI-330 and LARC(Trademark) PETI-9, were infused into carbon fiber preforms at 260 C and cured at temperatures up to 371 C. Photomicrographs of polished cross sections were taken and void contents, determined by acid digestion, were below 4.5%. Mechanical properties including short block compression (SBC), compression after impact (CAI), and open hole compression (OHC) were determined at room temperature, 177 C, and 288 C. Both PETI-9 and PETI-330 composites demonstrated very good retention of mechanical properties at elevated temperatures. SBC and OHC properties after aging for 1000 hours at temperatures up to 288 C were also determined.

  15. Color stability assessment of two different composite resins with variable immersion time using various beverages: An In vitro study

    Directory of Open Access Journals (Sweden)

    M Senthil Kumar

    2017-01-01

    Full Text Available Purpose of the Study: The aim of the study was to evaluate the difference in the color of microhybrid (MH and nanofilled (NF composite resins after 24 and 48 h in beverages such as red wine (RW, Coca-Cola, and distilled water. The specific objective of this study was to investigate the cumulative effect of the colorant solutions on the dental composites. Materials and Methods: MH and NF composite resins (A2 shade were used in this current study. Sixty disk-shaped material specimens (10 mm in diameter × 2 mm in thickness were prepared using a fiber mold (ring, with the desired dimensions. The specimen surfaces were polished using super-snap polishing system. Sixty specimens were divided into two groups of 30 each (Group I: MH resin composite; Group II: NF resin composite. Both the groups divided into six subgroups (Subgroup I: RW for 24 h [RW-24]; Subgroup II: RW for 48 h; Subgroup III: Coca-Cola for 24 h [CC-24]; Subgroup IV: Coca-Cola for 48 h [CC-48]; Subgroup V: Distilled water for 24 h [DW-24]; Subgroup VI: Distilled water for 48 h [DW-48]. All the samples were immersed in respective drinks for a period of 24 h, and color differences were measured using ultraviolet spectrophotometer. Once again, all the samples were immersed for another 24 h in the same drinks. After 48 h, the color change of the samples was measured. Measurements were made according to the CIE L × a × b × color space relative to the CIE standard illuminant D65. The color changes of the specimens were evaluated using the following formula: [INSIDE:1]Statistical analysis was performed. The data were analyzed using the one-way ANOVA and t-test at a significance level of 0.05. Conclusion: Color stability of MH composite resin was found to be inferior than the NF resin composite irrespective of immersion medium and time. In RW, the color change observed was maximum for both composite resins followed by Coca-Cola. Immersing the resin composites in distilled water for 24 and

  16. CURING OF POLYMERIC COMPOSITES USING MICROWAVE RESIN TRANSFER MOULDING (RTM

    Directory of Open Access Journals (Sweden)

    R. YUSOFF

    2007-08-01

    Full Text Available The main objective of this work is to compare the difference between microwave heating and conventional thermal heating in fabricating carbon/epoxy composites. Two types of epoxy resin systems were used as matrices, LY5052-HY5052 and DGEBA-HY917-DY073. All composite samples were fabricated using resin transfer moulding (RTM technique. The curing of the LY5052-HY5052-carbon and the DGEBA-HY917-DY073-carbon composite systems, were carried out at 100 °C and 120 °C, respectively. Microwave heating showed better temperature control than conventional heating, however, the heating rate of the microwave cured samples were slower than the conventionally cured samples. This was attributed to the lower power (250 W used when heating with microwaves compared to 2000 W used in conventional heating. Study of thermal characteristics as curing progressed showed that the polymerisation reaction occurred at a faster rate during microwave curing than in conventional curing for both the DGEBA and the LY/HY5052 carbon composite systems. The actual cure cycle was reduced from 60 minutes to 40 minutes when using microwaves for curing DGEBA-carbon composites. As for LY/HY5052-carbon composites, the actual cure cycle was reduced from 3 hours to 40 minutes. Both conventional and microwave heating yielded similar glass transition temperatures (120 °C for DGEBA systems and 130 °C for LY/HY5052 systems. Microwave cured composites had higher void contents than conventionally cured composites (2.2-2.8% and 1.8-2.4% for DGEBA and LY/HY5052 microwave cured composites, respectively, compared to 0.2-0.4% for both DGEBA and LY/HY5052 thermally cured composites. C-scan traces showed that all composites, regardless of methods of curing, had minimal defects.

  17. Effects of blood contamination on resin-resin bond strength.

    Science.gov (United States)

    Eiriksson, Sigurdur O; Pereira, Patricia N R; Swift, Edward J; Heymann, Harald O; Sigurdsson, Asgeir

    2004-02-01

    Incremental placement and curing of resin composites has been recommended. However, this requires longer operating time, and therefore, increased risk of contamination. The purpose of this study was to evaluate the effects of blood contamination on microtensile bond strengths (microTBS) between resin interfaces and to determine the best decontamination method to re-establish the original resin-resin bond strength. The top surfaces of 64, 4-mm composite blocks (Z-250, Renew, APX, Pertac II) were untreated as the control, or were treated as follows: blood applied and dried on the surface (Treatment 1), blood applied, rinsed, dried (Treatment 2), blood applied, rinsed, and an adhesive applied (Single Bond, One-Step, Clearfil SE, Prompt L-Pop) (Treatment 3). Fresh composite was applied and light-cured in 2-mm increments. After 24 h storage in water, the specimens were sectioned into 0.7-mm thick slabs, trimmed to a cross-sectional area of 1 mm(2), and loaded to failure at a crosshead speed of 1 mm/min using an Instron universal testing machine. Data were analyzed using two-way ANOVA and Fisher's PLSD test (pcontamination resulted in resin-resin bond strengths of only 1.0-13.1 MPa. Rinsing raised bond strengths to over 40 MPa for each material. Use of an adhesive further increased bond strengths except for Pertac II. Rinsing blood from contaminated surfaces increases the resin-resin bond strength significantly and the application of an appropriate adhesive increases the bond strength to control levels.

  18. Effect of Home Bleaching on Microleakage of Fiber-reinforced and Particle-filled Composite Resins

    Directory of Open Access Journals (Sweden)

    Farahnaz Sharafeddin

    2013-12-01

    Full Text Available Background and aims. Bleaching may exert some negative effects on existing composite resin restorations. The aim of this study was to evaluate the effect of home bleaching on microleakage of fiber-reinforced and particle-filled composite resins. Materials and methods. Ninety class V cavities (1.5×2×3 mm were prepared on the buccal surfaces of 90 bovine teeth. The teeth were randomly divided into 6 groups (n=15 and restored as follows: Groups 1 and 2 with Z100, groups 3 and 4 with Z250, and groups 5 and 6 with Nulite F composite resins. All the specimens were thermocycled. Groups 1, 3 and 5 were selected as control groups (without bleaching and the experimental groups 2, 4 and 6 were bleached with 22% carbamide peroxide gel. All the samples were immersed in 2% basic fuchsin dye for 24 hours and then sectioned longitudinally. Dye penetration was evaluated under a stereomicroscope (×25, at both the gingival and incisal margins. Data were analyzed using Kruskal-Wallis, Mann-Whitney and Wilcoxon tests (α=0.05. Results. Statistical analyses revealed that bleaching gel increased microleakage only at gingival margins with Z250 (P=0.007. Moreover, the control groups showed a statistically significant difference in microleakage at their gingival margins. Nulite F had the maximum microleakage while Z250 showed the minimum (P=0.006. Conclusion. Microleakage of home-bleached restorations might be related to the type of composite resin used.

  19. Endodontic complications in teeth with vital pulps restored with composite resins: a systematic review.

    Science.gov (United States)

    Dawson, V S; Amjad, S; Fransson, H

    2015-07-01

    Composite resin is used extensively for restoration of teeth with vital pulps. Although cell culture studies have disclosed harmful effects on pulpal cells, any untoward clinical effects, manifest as adverse pulpal responses, have yet to be determined. This study comprises a systematic review, designed to address the question of whether the risk of endodontic complications is greater with composite resin restorations than with other restorative materials, such as amalgam. The study methodology involved (i) formulation of the research question, (ii) construction and conduct of an extensive literature search with (iii) interpretation and assessment of the retrieved literature. A search of the medical database PubMed was complemented with a search of the Controlled Trials Register (CENTRAL). The initial search yielded 1043 publications, the abstracts of which were read independently by the authors. After additional searches, 10 studies were included in the review. In all the included studies, the level of evidence was assessed as low. No conclusions could therefore be drawn. The included studies reported few, if any, endodontic complications. Little or no differences emerged between teeth restored with composite resins and those restored with amalgam. To determine whether composite resin restorations of teeth with vital pulps are associated with an increased risk for development of endodontic complications such as apical periodontitis, further evidence is needed, from well-constructed studies with a large number of participants. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  20. Effect of different light curing units on Knoop hardness and temperature of resin composite

    Directory of Open Access Journals (Sweden)

    Guiraldo Ricardo

    2009-01-01

    Full Text Available Aim: To evaluate the influence of quartz tungsten halogen and plasma arc curing (PAC lights on Knoop hardness and change in polymerization temperature of resin composite. Materials and Methods: Filtek Z250 and Esthet X composites were used in the shade A3. The temperature increase was registered with Type-k thermocouple connected to a digital thermometer (Iopetherm 46. A self-cured polymerized acrylic resin base was built in order to guide the thermocouple and to support the dentin disk of 1.0 mm thickness obtained from bovine tooth. On the acrylic resin base, elastomer mold of 2.0 mm was adapted. The temperature increase was measured after composite light curing. After 24 h, the specimens were submitted to Knoop hardness test (HMV-2000, Shimadzu, Tokyo, Japan. Data were submitted to ANOVA and Tukey′s test (a = 0.05. Results: For both composites, there were no significant differences (P > 0.05 in the top surface hardness; however, PAC promoted statistically lower (P < 0.05 Knoop hardness number values in the bottom. The mean temperature increase showed no significant statistical differences (P > 0.05. Conclusion: The standardized radiant exposure showed no influence on the temperature increase of the composite, however, showed significant effect on hardness values.

  1. Initial Development of Composite Repair Resins With Low Hazardous Air Pollutant Contents

    National Research Council Canada - National Science Library

    LaScala, John J; Bingham, Scott; Andrews, Kevin S; Sands, James M; Palmese, Guiseppe R

    2008-01-01

    Unsaturated polyester-based repair resins, such a Bondo, are widely used for automotive repair, marine repair, sporting equipment repair, and household repair of metal, composites, plastics, and wood...

  2. [A new machinability test machine and the machinability of composite resins for core built-up].

    Science.gov (United States)

    Iwasaki, N

    2001-06-01

    A new machinability test machine especially for dental materials was contrived. The purpose of this study was to evaluate the effects of grinding conditions on machinability of core built-up resins using this machine, and to confirm the relationship between machinability and other properties of composite resins. The experimental machinability test machine consisted of a dental air-turbine handpiece, a control weight unit, a driving unit of the stage fixing the test specimen, and so on. The machinability was evaluated as the change in volume after grinding using a diamond point. Five kinds of core built-up resins and human teeth were used in this study. The machinabilities of these composite resins increased with an increasing load during grinding, and decreased with repeated grinding. There was no obvious correlation between the machinability and Vickers' hardness; however, a negative correlation was observed between machinability and scratch width.

  3. Process for curing ionizing radiation-highly sensitive resin composition

    International Nuclear Information System (INIS)

    Araki, K.; Sasaki, T.; Tabei, K.; Goto, K.

    1979-01-01

    A process is described for curing a radiation curable composition consisting essentially of (a) an amide represented by the formula R,CONR 2 R 3 and (b) an unsaturated polyester resin by irradiating the composition with an ionizing radiation. R 1 is H, an alkyl groups having from 1 to 17 carbon atoms or an alkenyl groups having from 1 to 17 carbon atoms, and R 2 and R 3 are each -H, -CH 3 , or -CH 2 OH. R 1 and R 2 taken together represent alkylene having 2 to 5 carbon atoms

  4. Flexural properties of polyethylene, glass and carbon fiber-reinforced resin composites for prosthetic frameworks.

    Science.gov (United States)

    Maruo, Yukinori; Nishigawa, Goro; Irie, Masao; Yoshihara, Kumiko; Minagi, Shogo

    2015-01-01

    High flexural properties are needed for fixed partial denture or implant prosthesis to resist susceptibility to failures caused by occlusal overload. The aim of this investigation was to clarify the effects of four different kinds of fibers on the flexural properties of fiber-reinforced composites. Polyethylene fiber, glass fiber and two types of carbon fibers were used for reinforcement. Seven groups of specimens, 2 × 2 × 25 mm, were prepared (n = 10 per group). Four groups of resin composite specimens were reinforced with polyethylene, glass or one type of carbon fiber. The remaining three groups served as controls, with each group comprising one brand of resin composite without any fiber. After 24-h water storage in 37°C distilled water, the flexural properties of each specimen were examined with static three-point flexural test at a crosshead speed of 0.5 mm/min. Compared to the control without any fiber, glass and carbon fibers significantly increased the flexural strength (p glass fiber (p glass fibers (p > 0.05). Fibers could, therefore, improve the flexural properties of resin composite and carbon fibers in longitudinal form yielded the better effects for reinforcement.

  5. Wear of human enamel opposing monolithic zirconia, glass ceramic, and composite resin: an in vitro study.

    Science.gov (United States)

    Sripetchdanond, Jeerapa; Leevailoj, Chalermpol

    2014-11-01

    Demand is increasing for ceramic and composite resin posterior restorations. However, ceramics are recognized for their high abrasiveness to opposing dental structure. The purpose of this study was to investigate the wear of enamel as opposed to dental ceramics and composite resin. Twenty-four test specimens (antagonists), 6 each of monolithic zirconia, glass ceramic, composite resin, and enamel, were prepared into cylindrical rods. Enamel specimens were prepared from 24 extracted human permanent molar teeth. Enamel specimens were abraded against each type of antagonist with a pin-on-disk wear tester under a constant load of 25 N at 20 rpm for 4800 cycles. The maximum depth of wear (Dmax), mean depth of wear (Da), and mean surface roughness (Ra) of the enamel specimens were measured with a profilometer. All data were statistically analyzed by 1-way ANOVA, followed by the Tukey test (α=.05). A paired t test was used to compare the Ra of enamel at baseline and after testing. The wear of both the enamel and antagonists was evaluated qualitatively with scanning electron microscopic images. No significant differences were found in enamel wear depth (Dmax, Da) between monolithic zirconia (2.17 ±0.80, 1.83 ±0.75 μm) and composite resin (1.70 ±0.92, 1.37 ±0.81 μm) or between glass ceramic (8.54 ±2.31, 7.32 ±2.06 μm) and enamel (10.72 ±6.31, 8.81 ±5.16 μm). Significant differences were found when the enamel wear depth caused by monolithic zirconia and composite resin was compared with that of glass ceramic and enamel (Pglass ceramic, and enamel (Pglass ceramic and enamel. All test materials except composite resin similarly increased the enamel surface roughness after wear testing. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  6. Fracture Resistance of Endodontically Treated Teeth Restored with 2 Different Fiber-reinforced Composite and 2 Conventional Composite Resin Core Buildup Materials: An In Vitro Study.

    Science.gov (United States)

    Eapen, Ashly Mary; Amirtharaj, L Vijay; Sanjeev, Kavitha; Mahalaxmi, Sekar

    2017-09-01

    The purpose of this in vitro study was to comparatively evaluate the fracture resistance of endodontically treated teeth restored with 2 fiber-reinforced composite resins and 2 conventional composite resin core buildup materials. Sixty noncarious unrestored human maxillary premolars were collected, endodontically treated (except group 1, negative control), and randomly divided into 5 groups (n = 10). Group 2 was the positive control. The remaining 40 prepared teeth were restored with various direct core buildup materials as follows: group 3 teeth were restored with dual-cure composite resin, group 4 with posterior composite resin, group 5 with fiber-reinforced composite resin, and group 6 with short fiber-reinforced composite resin. Fracture strength testing was performed using a universal testing machine. The results were statistically analyzed by 1-way analysis of variance and the post hoc Tukey test. Fracture patterns for each sample were also examined under a light microscope to determine the level of fractures. The mean fracture resistance values (in newtons) were obtained as group 1 > group 6 > group 4 > group 3 > group 5 > group 2. Group 6 showed the highest mean fracture resistance value, which was significantly higher than the other experimental groups, and all the fractures occurred at the level of enamel. Within the limitations of this study, a short fiber-reinforced composite can be used as a direct core buildup material that can effectively resist heavy occlusal forces against fracture and may reinforce the remaining tooth structure in endodontically treated teeth. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Gloss and surface roughness produced by polishing kits on resin composites.

    Science.gov (United States)

    Sadidzadeh, Ramtin; Cakir, Deniz; Ramp, Lance C; Burgess, John O

    2010-08-01

    To compare in vitro the surface roughness (Ra) and gloss (G) produced by three conventional and one experimental polishing kits on four resin composites. 24 discs were prepared (d = 12 mm, t = 4 mm) for each resin composite: Filtek Supreme Plus Body/A2 (FSB), Yellow Translucent (FST), Heliomolar/A2 (HM), and EsthetX/A2 (EX) following the manufacturers' instructions. They were finished with 320 grit silicon carbide paper for 80 seconds each. Polishing systems: Sof-Lex, Enhance-Pogo, Astropol and Experimental Discs/EXL-695, were applied following manufacturers' instructions. Each specimen was ultrasonically cleaned with distilled water and dried. Gloss and Ra were measured with a small area glossmeter (Novo-curve) and non-contact profilometer (Proscan 2000) following ISO 4288, respectively. The results were evaluated by two-way ANOVA followed by separate one-way ANOVA and Tukey/Kramer test (P = 0.05). There was a significant interaction of surface roughness and gloss between the composites and polishing systems (P gloss was obtained for FSB composite polished with the Experimental kit. The experimental polishing system produced smoothest surfaces (P gloss (P < 0.05).

  8. A long-term laboratory test on staining susceptibility of esthetic composite resin materials

    NARCIS (Netherlands)

    Ardu, S.; Braut, V.; Gutemberg, D.; Krejci, I.; Dietschi, D.; Feilzer, A.J.

    2010-01-01

    Objective: To evaluate the color stability of composite resin types designed for esthetic anterior restorations when continuously exposed to various staining agents. Method and Materials: Thirty-six disk-shaped specimens were made of each of 12 composite materials (1 microfilled and 11 hybrid

  9. Elution of monomer from different bulk fill dental composite resins.

    Science.gov (United States)

    Cebe, Mehmet Ata; Cebe, Fatma; Cengiz, Mehmet Fatih; Cetin, Ali Rıza; Arpag, Osman Fatih; Ozturk, Bora

    2015-07-01

    The purpose of this study was to evaluate the elution of Bis-GMA, TEGDMA, HEMA, and Bis-EMA monomers from six bulk fill composite resins over four different time periods, using HPLC. Six different composite resin materials were used in the present study: Tetric Evo Ceram Bulk Fill (Ivoclar Vivadent, Amherst, NY), X-tra Fill (VOCO, Cuxhaven, Germany), Sonic Fill (Kerr, Orange, CA, USA), Filtek Bulk Fill (3M ESPE Dental Product, St. Paul, MN), SDR (Dentsply, Konstanz, Germany), EQUIA (GC America INC, Alsip, IL). The samples (4mm thickness, 5mm diameter) were prepared and polymerized for 20s with a light emitted diode unit. After fabrication, each sample was immediately immersed in 75wt% ethanol/water solution used as extraction fluid and stored in the amber colored bottles at room temperature. Ethanol/water samples were taken (0.5mL) at predefined time intervals:10m (T1), 1h (T2), 24h (T3) and 30 days (T4). These samples were analyzed by HPLC. The obtained data were analyzed with one-way ANOVA and Tukey HSD at significance level of pcomposites (pcomposite resins in all time periods and the amount of eluted monomers was increased with time. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. Amalgam stained dentin: a proper substrate for bonding resin composite?

    NARCIS (Netherlands)

    Scholtanus, J.D.

    2016-01-01

    Nowadays the use of dental amalgam is mostly abandoned and substituted by tooth colored resin composites that can be bonded to teeth tissues by adhesive techniques. The aim of this thesis was to find out whether dark stained dentin, as often observed after removal of amalgam restorations and

  11. Chemical recycling of carbon fibers reinforced epoxy resin composites in oxygen in supercritical water

    International Nuclear Information System (INIS)

    Bai, Yongping; Wang, Zhi; Feng, Liqun

    2010-01-01

    The carbon fibers in carbon fibers reinforced epoxy resin composites were recovered in oxygen in supercritical water at 30 ± 1 MPa and 440 ± 10 o C. The microstructure of the recovered carbon fibers was observed using scanning electron microscopy (SEM) and atom force microscopy (AFM). The results revealed that the clean carbon fibers were recovered and had higher tensile strength relative to the virgin carbon fibers when the decomposition rate was above 85 wt.%, although the recovered carbon fibers have clean surface, the epoxy resin on the surface of the recovered carbon fibers was readily observed. As the decomposition rate increased to above 96 wt.%, no epoxy resin was observed on the surface of the carbon fibers and the oxidation of the recovered carbon fibers was readily measured by X-ray photoelectron spectroscopy (XPS) analysis. The carbon fibers were ideally recovered and have original strength when the decomposition rates were between 94 and 97 wt.%. This study clearly showed the oxygen in supercritical water is a promising way for recycling the carbon fibers in carbon fibers reinforced resin composites.

  12. Rugometric and microtopographic non-invasive inspection in dental-resin composites and zirconia ceramics

    Science.gov (United States)

    Fernández-Oliveras, Alicia; Costa, Manuel F. M.; Pecho, Oscar E.; Rubiño, Manuel; Pérez, María. M.

    2013-11-01

    Surface properties are essential for a complete characterization of biomaterials. In restorative dentistry, the study of the surface properties of materials meant to replace dental tissues in an irreversibly diseased tooth is important to avoid harmful changes in future treatments. We have experimentally analyzed the surface characterization parameters of two different types of dental-resin composites and pre-sintered and sintered zirconia ceramics. We studied two shades of both composite types and two sintered zirconia ceramics: colored and uncolored. Moreover, a surface treatment was applied to one specimen of each dental-resin. All the samples were submitted to rugometric and microtopographic non-invasive inspection with the MICROTOP.06.MFC laser microtopographer in order to gather meaningful statistical parameters such as the average roughness (Ra), the root-mean-square deviation (Rq), the skewness (Rsk), and the kurtosis of the surface height distribution (Rku). For a comparison of the different biomaterials, the uncertainties associated to the surface parameters were also determined. With respect to Ra and Rq, significant differences between the composite shades were found. Among the dental resins, the nanocomposite presented the highest values and, for the zirconia ceramics, the pre-sintered sample registered the lowest ones. The composite performance may have been due to cluster-formation variations. Except for the composites with the surface treatment, the sample surfaces had approximately a normal distribution of heights. The surface treatment applied to the composites increased the average roughness and moved the height distribution farther away from the normal distribution. The zirconia-sintering process resulted in higher average roughness without affecting the height distribution.

  13. Ion release from a composite resin after exposure to different 10% carbamide peroxide bleaching agents

    Directory of Open Access Journals (Sweden)

    Renata Plá Rizzolo Bueno

    2012-06-01

    Full Text Available OBJECTIVE: This in vitro study evaluated the influence of two 10% carbamide peroxide bleaching agents - a commercial product (Opalescence PF; Ultradent Products, Inc. and a bleaching agent prepared in a compounding pharmacy - on the chemical degradation of a light-activated composite resin by determining its release of ions before and after exposure to the agents. MATERIAL AND METHODS: Thirty composite resin (Filtek Z250; 3M/ESPE samples were divided into three groups: group I (exposed to Opalescence PF commercial bleaching agent, group II (exposed to a compounded bleaching agent and group III (control - Milli-Q water. After 14 days of exposure, with a protocol of 8 h of daily exposure to the bleaching agents and 16 h of immersion in Milli-Q water, the analysis of ion release was carried out using a HP 8453 spectrophotometer. The values were analyzed statistically by ANOVA, Tukey's test and the paired t-tests. The significance level was set at 5%. RESULTS: After 14 days of the experiment, statistically significant difference was found between group II and groups I and III, with greater ion release from the composite resin in group II. CONCLUSIONS: The compounded bleaching agent had a more aggressive effect on the composite resin after 14 days of exposure than the commercial product and the control (no bleaching.

  14. [In vitro study of marginal microleakage of Clearfil S3 BOND adhesive systems and Majesty composite resin].

    Science.gov (United States)

    Wang, Bei; Zhu, Ya-qin

    2009-08-01

    To evaluate the microleakage of standard box-type cavity filled with Clearfil S3 BOND self-etch adhesive systems and Majesty composite resin. 40 permanent molars were randomly divided into experimental and control groups, 20 of each . The box-type cavities, 3mm in length and width and 2mm in depth, were prepared at the cemento-enamel junction on buccal surface of forty permanent extracted teeth. According to grouping, the experimental group was filled with Clearfil S(3) BOND self-adhesive systems and Majesty composite resin, and the control group was filled with 3M Adper Prompt self-adhesive and Filtek Z350 composite resin. After thermal circulation(2000 times, 5 degrees centigrade-55 degrees centigrade) and soaked for 24 hours in 2% methyl blue solution, the samples were cut through the midline of the restoration and the leakage depth was measured with vernier caliper. The microleakage degrees and microleakage depth of 2 groups were analyzed with SPSS 17.0 software package for Mann-Whitney U test and independent-samples t test. Microleakage was observed in both groups. But the microleakage degrees and microleakage depth of 2 groups had no significant difference (P>0.05). The marginal sealibility of Clearfil S(3) BOND self-adhesive systems and Majesty composite resin is as good as Adper Prompt self-adhesive and Filtek Z350 composite resin,it may be an ideal clinical restoration material.

  15. Influence of polymerization time and depth of cure of resin composites determined by Vickers hardness

    Directory of Open Access Journals (Sweden)

    Marco Lombardini

    2012-01-01

    Conclusion: Among the materials tested, the nanofilled and the nanohybrid resin composites were rather insensible to thickness variations. Miicrohybrid composites, instead, had features different from one another.

  16. Resin transfer molding for advanced composite primary aircraft structures

    Science.gov (United States)

    Markus, Alan; Palmer, Ray

    1991-01-01

    Resin Transfer Molding (RTM) has been identified by Douglas Aircraft Company (DAC) and industry to be one of the promising processes being developed today which can break the cost barrier of implementing composite primary structures into a commercial aircraft production environment. The RTM process developments and scale-up plans Douglas Aircrart will be conducting under the NASA ACT contract are discussed.

  17. Effect of natural fibers and bio-resins on mechanical properties in hybrid and non-hybrid composites

    Science.gov (United States)

    Fragassa, Cristiano

    2016-05-01

    The aim of the present experimental investigation was to perform a comparative analysis concerning the influence on mechanical properties of natural fibers and/or bio-resins in reinforced thermoset composites. Flax and basalt fibers were selected as natural reinforcements, as single constituents or in hybrid combination. Glass synthetic fibers were used for comparison. Eco-friendly matrixes, both epoxy or vinylester, were considered and compared with composites based on traditional resins. Samples were fabricated by hand lay-up and resin infusion techniques. Cures were accelerated and controlled by applying heat and pressure in autoclave. Tensile, flexural and impact tests were carried out according to ASTM standards.

  18. The effects of different opacifiers on the translucency of experimental dental composite resins.

    Science.gov (United States)

    Haas, Karine; Azhar, Gulelala; Wood, Duncan J; Moharamzadeh, Keyvan; van Noort, Richard

    2017-08-01

    The aim of this study was to evaluate the effects of different opacifiers on the translucency of experimental dental composite-resins. Three metal oxides that are used as opacifiers were tested in this study: titanium oxide (TiO 2 ), aluminium oxide (Al 2 O 3 ) and zirconium oxide (ZrO 2 ). Experimental composite-resins were fabricated containing 25wt.% urethane dimethacrylate (UDMA)-based resin matrix and 75% total filler including different concentrations of metal oxides (0, 0.25, 0.5, 0.75 and 1wt.%) blended into silane treated barium-silicate filler. The specimens (15.5mm diameter and 1mm thickness) were light-cured and tested in the transmittance mode using a UV/VIS spectrophotometer at wavelengths from 380 to 700nm under a standard illuminant D65. The color differences (ΔE* ab) between different concentrations of opacifiers were also measured in transmittance mode based on their Lab values. Statistical analysis by ANOVA and Tukey's test showed a significant decrease (pcomposite-resins. There was a linear correlation between different concentrations of TiO 2 and Al 2 O 3 and total transmittance. Total transmittance was also found to be wavelength dependent. The color differences for the concentrations of 0-1wt.% of the opacifiers were above 1 ΔE* unit, with Al 2 O 3 showing the smallest color shift. The type and the amount of the opacifiers used in this study had a significant effect on the translucency of the experimental UDMA-based dental composite resins. The most effective opacifier was TiO 2 , followed by ZrO 2 and Al 2 O 3 in decreasing order, respectively. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  19. Color recovery effect of different bleaching systems on a discolored composite resin.

    Science.gov (United States)

    Gul, P; Harorlı, O T; Ocal, I B; Ergin, Z; Barutcigil, C

    2017-10-01

    Discoloration of resin-based composites is a commonly encountered problem, and bleaching agents may be used for the therapy of the existing discoloration. The purpose of this study was to investigate in vitro color recovery effect of different bleaching systems on the heavily discolored composite resin. Fifty disk-shaped dental composite specimens were prepared using A2 shade nanohybrid universal composite resin (3M ESPE Filtek Z550, St. Paul, MN, USA). Composite samples were immersed in coffee and turnip juice for 1 week in each. One laser activated bleaching (LB) (Biolase Laserwhite*20) and three conventional bleaching systems (Ultradent Opalescence Boost 40% (OB), Ultradent Opalescence PF 15% home bleaching (HB), Crest 3D White [Whitening Mouthwash]) were tested in this study. Distilled water was used as control group. The color of the samples were measured using a spectrophotometer (VITA Easy shade Compact, VITA Zahnfabrik, Bad Säckingen, Germany). Color changes (ΔE00) were calculated using the CIEDE2000 formula. Statistical analyses were conducted using paired samples test, one-way analysis of variance, and Tukey's multiple comparison tests (α = 0.05). The staining beverages caused perceptible discoloration (ΔE00 > 2.25). The color recovery effect of all bleaching systems was statistically determined to be more effective than the control group (P OB group was found as the most effective bleaching system, there was no statistically significant difference among HB, OB, and LB groups (P > 0.05). Within the limitation of this in vitro study, the highest recovery effect was determined in office bleaching system among all bleaching systems. However, home and laser bleaching systems were determined as effective as office bleaching system.

  20. Effect of γ irradiation on the properties of basalt fiber reinforced epoxy resin matrix composite

    International Nuclear Information System (INIS)

    Li, Ran; Gu, Yizhuo; Yang, Zhongjia; Li, Min; Wang, Shaokai; Zhang, Zuoguang

    2015-01-01

    Gamma-ray (γ-ray) irradiation is a crucial reason for the aging in materials used for nuclear industry. Due to high specific strength and stiffness, light weight and good corrosion resistance, fiber reinforced composites are regarded as an alternative of traditional materials used on nuclear facilities. In this study, basalt fiber (BF)/AG80 epoxy composite laminates were fabricated by autoclave process and treated with "6"0Co gamma irradiation dose up to 2.0 MGy. Irradiation induced polymer chain scission and oxidation of AG80 resin were detected from physical and chemical analysis. The experimental results show that the tensile and flexural performances of irradiated BF/AG80 composite maintain stable and have a low amplitude attenuation respectively, and the interlaminar shear strength has increased from irradiation dose of 0–1.5 MGy. Furthermore, the comparison between the studied BF composite and reported polymer and composite materials was done for evaluating the γ resistance property of BF composite. - Highlights: • The properties of basalt fiber reinforced epoxy resin matrix composite under "6"0Co γ irradiation up to 2.0 MGy were studied. • Basalt fiber can weaken the aging effects of γ irradiation on the resin matrix. • Tensile property of basalt fiber composite remains stable and flexural property has a low degree of attenuation. • Basalt fiber composite is an ideal candidate of structural material for nuclear industry.

  1. The effect of chemical composition and granulation of Fe - based fillers on properties of metal resinous composite

    International Nuclear Information System (INIS)

    Janecki, J.; Dasiewicz, J.; Pawelec, Z.

    2000-01-01

    In this paper the authors present metal-resinous composites with Fe based fillers of various element constitution and granulation. The analysis of influence of filler type on coefficient of linear thermal expansion of composite materials was performed. Friction and wear tests (composite-bronze and composite-steel pairs) were carried out. It was stated that the thinner granulation of main filler has a positive effect on coefficient of linear thermal expansion and friction/wear characteristics. The presence of copper, nickel and molybdenum in the filler is beneficial for some properties of the composite. (author)

  2. "Greener" hybrid adhesives composed of urea formaldehyde resin and cottonseed meal for wood based composites

    Science.gov (United States)

    Urea formaldehyde (UF) resins are one of the most widely used adhesives in wood based composites. The major concerns of the resin utilization are free formaldehyde release and poor water resistance. As a renewable raw materials, water washed conttonseed meal can be used in wood bonding. To produce “...

  3. Can Whitening Strips interfere with the Bond Strength of Composite Resins?

    Science.gov (United States)

    Firoozmand, Leily Macedo; Reis, Washington Luís Machado dos; Vieira, Mercêdes Aroucha; Nunes, Adriana Gomes; Tavarez, Rudys Rodolfo de Jesus; Tonetto, Mateus Rodrigues; Bramante, Fausto Silva; Bhandi, Shilpa H; Roma, Regina Vieira de Oliveira; Bandeca, Matheus Coelho

    2015-04-01

    The aim of this study was to investigate in vitro the bond strength of composite resins on enamel previously treated with whitening strips. A total of 48 bovine incisors were allocated to four experimental groups (n = 12 each): G1 (WSC)- treated with 9.5% hydrogen peroxide whitening strips (3D White Whitestrips® Advanced Vivid/CREST); G2 (WSO)-treated with 10% hydrogen peroxide whitening strips (3D WhiteTM/Oral B); G3 (WG)-treated with 7.5% hydrogen peroxide gel with fluorine, calcium and potassium nitrate (White Class®/FGM); and G4 (C)-control not subjected to bleaching treatment. The specimens were subjected to bleaching over 2 weeks following the manufacturers' instructions. Following the elaboration of the composite resin test specimens, the samples were stored in artificial saliva and subsequently subjected to the micro-shear test using the universal testing machine (EMIC®). The bond strength values were analyzed by one-way ANOVA and Tukey's statistical test (5%). Significant differences were observed among the investigated groups (p enamel-resin interface. The bond strength decreased following 14 days of treatment with bleaching strips, whereas the whitening gel with 7.5% hydrogen peroxide, calcium and fluorine increased the bond strength.

  4. Current-Voltage Characteristics of the Composites Based on Epoxy Resin and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Iwona Pełech

    2015-01-01

    Full Text Available Polymer composites based on epoxy resin were prepared. Multiwalled carbon nanotubes synthesized on iron-cobalt catalyst were applied as a filler in a polymer matrix. Chlorine or hydroxyl groups were incorporated on the carbon nanotubes surface via chlorination or chlorination followed by hydroxylation. The effect of functionalized carbon nanotubes on the epoxy resin matrix is discussed in terms of the state of CNTs dispersion in composites as well as electrical properties. For the obtained materials current-voltage characteristics were determined. They had a nonlinear character and were well described by an exponential-type equation. For all the obtained materials the percolation threshold occurred at a concentration of about 1 wt%. At a higher filler concentration >2 wt%, better conductivity was demonstrated by polymer composites with raw carbon nanotubes. At a lower filler concentration <2 wt%, higher values of electrical conductivity were obtained for polymer composites with modified carbon nanotubes.

  5. Correlation of shear and dielectric ion viscosity of dental resins - Influence of composition, temperature and filler content.

    Science.gov (United States)

    Steinhaus, Johannes; Hausnerova, Berenika; Haenel, Thomas; Selig, Daniela; Duvenbeck, Fabian; Moeginger, Bernhard

    2016-07-01

    Shear viscosity and ion viscosity of uncured visible light-curing (VLC) resins and resin based composites (RBC) are correlated with respect to the resin composition, temperature and filler content to check where Dielectric Analysis (DEA) investigations of VLC RBC generate similar results as viscosity measurements. Mixtures of bisphenol A glycidyl methacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) as well as the pure resins were investigated and compared with two commercial VLC dental resins and RBCs (VOCO, Arabesk Top and Grandio). Shear viscosity data was obtained using a Haake Mars III, Thermo Scientific. Ion viscosity measurements performed by a dielectric cure analyzer (DEA 231/1 Epsilon with Mini IDEX-Sensor, Netzsch-Gerätebau). Shear viscosity depends reciprocally on the mobility of molecules, whereas the ion viscosity also depends on the ion concentration as it is affected by both ion concentration and mixture viscosity. Except of pure TEGDMA, shear and ion viscosities depend on the resin composition qualitatively in a similar manner. Furthermore, shear and ion viscosities of the commercial VLC dental resins and composites exhibited the same temperature dependency regardless of filler content. Application of typical rheological models (Kitano and Quemada) revealed that ion viscosity measurements can be described with respect to filler contents of up to 30vol.%. Rheological behavior of a VLC RBC can be characterized by DEA under the condition that the ion concentration is kept constant. Both methods address the same physical phenomenon - motion of molecules. The proposed relations allows for calculating the viscosity of any Bis-GMA-TEGDMA mixture on the base of the viscosities of the pure components. This study demonstrated the applicability of DEA investigations of VLC RBCs with respect to quality assurance purposes. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Analytical methods for the measurement of polymerization kinetics and stresses of dental resin-based composites: A review

    Directory of Open Access Journals (Sweden)

    Mehrsima Ghavami-Lahiji

    2017-01-01

    Full Text Available Resin-based composites are commonly used restorative materials in dentistry. Such tooth-colored restorations can adhere to the dental tissues. One drawback is that the polymerization shrinkage and induced stresses during the curing procedure is an inherent property of resin composite materials that might impair their performance. This review focuses on the significant developments of laboratory tools in the measurement of polymerization shrinkage and stresses of dental resin-based materials during polymerization. An electronic search of publications from January 1977 to July 2016 was made using ScienceDirect, PubMed, Medline, and Google Scholar databases. The search included only English-language articles. Only studies that performed laboratory methods to evaluate the amount of the polymerization shrinkage and/or stresses of dental resin-based materials during polymerization were selected. The results indicated that various techniques have been introduced with different mechanical/physical bases. Besides, there are factors that may contribute the differences between the various methods in measuring the amount of shrinkages and stresses of resin composites. The search for an ideal and standard apparatus for measuring shrinkage stress and volumetric polymerization shrinkage of resin-based materials in dentistry is still required. Researchers and clinicians must be aware of differences between analytical methods to make proper interpretation and indications of each technique relevant to a clinical situation.

  7. COMPOSITE RESIN BOND STRENGTH TO ETCHED DENTINWITH ONE SELF PRIMING ADHESIVE

    Directory of Open Access Journals (Sweden)

    P SAMIMI

    2002-09-01

    Full Text Available Introduction. The purpose of this study was to compare shear bond strength of composite resins to etched dentin in both dry and wet dentin surface with active and inactive application of a single-bottle adhesive resin (Single Bond, 3M Dental products. Methods. Fourthy four intact human extracted molars and premolars teeth were selected. The facial surfaces of the teeth were grounded with diamond bur to expose dentin. Then specimens were divided into four groups of 11 numbers (9 Molars and 2 Premolars. All the samples were etched with Phosphoric Acid Gel 35% and then rinsed for 10 seconds. The following stages were carried out for each group: Group I (Active-Dry: After rinsing, air drying of dentin surface for 15 seconds, active priming of adhesive resin for 15 seconds, air drying for 5 seconds, the adhesive resin layer was light cured for 10 seconds. Group III (Inactive-Dry:After rinsing, air drying of dentin surface for 15 seconds, adhesive resin was applied and air dryied for 5 seconds, the adhesive layer was light cured for 10 seconds. Group III (Active-Wet:After rinsing, removal of excess water of dentin surface with a cotton roll, active priming of adhesive resin for 15 seconds and air drying for 5 seconds, the adhesive layer was light cured for 10 seconds. Group IV (Inactive-Wet:After rinsing, removal of excess water of dentin surface with a cotton roll, the adhesive resin was applied and air dryied for 5 seconds and then cured for 10 seconds. After adhesive resin application, composite resin (Z250, 3M Dental products was applied on prepared surface with cylindrical molds (with internal diameter of 2.8mm, & height of 5mm and light-cured for 100 seconds (5x20s. The samples were then thermocycled. They were located in 6±3c water .temperature for 10 seconds and then 15 seconds in inviromental temperature, 10s in 55±3c water temperature and then were located at room temperature for 15s. This test was repeated for 100s. All of the specimens

  8. CHEMICAL COMPOSITIONS OF PINE RESIN, ROSIN AND TURPENTINE OIL FROM WEST JAVA

    Directory of Open Access Journals (Sweden)

    Bambang Wiyono

    2006-03-01

    Full Text Available This study was conducted to identify chemical composition of merkus pine resin, rosin and turpentine oil. Initially, pine resin was separated into neutral and acidic fractions with an aqueous 4% sodium hydroxide solution. After methylation, the fraction containing turpentine oil and rosin were analyzed by gas chromatography (GC, and gas chromatograph mass spectrometry (GC-MS, respectively. The neutral fraction of pine resin and turpentine oil mainly consisted of a-pinene, D-3-carene and b-pinene. Based on mass spectral comparison, the major constituents of the acidic fraction and rosin were identified as sandaracopimaric acid, isopimaric acid, palustric acid, dehydroabietic acid, abietic acid, neoabietic acid, and merkusic acid. The major component of the acidic fractions was palustric acid, while that of rosin was abietic acid. Using TC (tough column 1 and TC 5 columns, levopimaric acid could not be separated from rosin or acidic fraction of pine resin of Indonesian Pinus merkusii.

  9. Space charge distributions in glass fibre/epoxy resin composites under dc 10 kV mm-1 electric field

    International Nuclear Information System (INIS)

    Tanaka, Hidesato; Ohki, Yoshimichi; Fukunaga, Kaori; Maeno, Takashi; Okamoto, Kenji

    2007-01-01

    In this paper, the authors discuss one- and three-dimensional space charge distributions in glass fibre/epoxy resin composites. By the conventional pulsed electroacoustic (PEA) method, only a one-dimensional distribution of the average charge over a whole area parallel to the two electrodes can be observed. Therefore, the authors have developed a new PEA system capable of measuring a three-dimensional space charge distribution. Using this system, they measured the charge distribution in glass fibre/epoxy resin composites made of lattice-woven glass fibre and epoxy resin. It has become clear that spatial variation in signal intensity observed depends on the internal structure of the composite. There appear repetitious positions where a high charge density is observed on the same lateral cross section along the vertical direction in the composite. Such positions are consistent with the intersections of the glass fibres. Accumulation of mobile charge carriers or appearance of polarization charge due to mismatch of the ratio of the conductivity and permittivity between the glass fibre and the epoxy resin is thought to be responsible for the PEA signals

  10. Magnetocaloric effect and corrosion resistance of La(Fe, Si)13 composite plates bonded by different fraction of phenolic resin

    Science.gov (United States)

    Zhang, K. S.; Xue, J. N.; Wang, Y. X.; Sun, H.; Long, Y.

    2018-04-01

    La(Fe, Si)13-based composite plates were successfully fabricated using different amount of phenolic resin. The introduction of phenolic resin as binder increased the corrosion resistance and maintained giant magnetocaloric effect for La(Fe, Si)13-based composite plates. It was found that corroded spots were firstly observed on the boundaries between resin and La(Fe, Si)13 particles, rather than in La(Fe, Si)13-based particles, after being immersed in static distilled water. The corrosion rate decreased significantly with the increase of resin content. And the increase of the content of phenolic resin leads to the reduction of corrosion current density. Meanwhile, the volumetric magnetic entropy change ΔSM decreases slightly as the content of phenolic resin increases. The ΔSM of the plates with 3 wt.%, 5 wt.% and 8 wt.% resin are 63.1, 61.2 and 59.8 mJ/cm3 K under a low magnetic field change of 1 T, respectively.

  11. Effect of different bleaching strategies on microhardness of a silorane-based composite resin.

    Science.gov (United States)

    Bahari, Mahmoud; Savadi Oskoee, Siavash; Mohammadi, Narmin; Ebrahimi Chaharom, Mohammad Esmaeel; Godrati, Mostafa; Savadi Oskoee, Ayda

    2016-01-01

    Background. Dentists' awareness of the effects of bleaching agents on the surface and mechanical properties of restorative materials is of utmost importance. Therefore, this in vitro study was undertaken to investigate the effects of different bleaching strategies on the microhardness of a silorane-based composite resin. Methods. Eighty samples of a silorane-based composite resin (measuring 4 mm in diameter and 2 mm in thickness) were prepared within acrylic molds. The samples were polished and randomly assigned to 4 groups (n=20). Group 1 (controls) were stored in distilled water for 2 weeks. The samples in group 2 underwent a bleaching procedure with 15% carbamide peroxide for two weeks two hours daily. The samples in group 3 were bleached with 35% hydrogen peroxide twice 5 days apart for 30 minutes each time. The samples in group 4 underwent a bleaching procedure with light-activated 35% hydrogen peroxide under LED light once for 40 minutes. Then the microhardness of the samples was determined using Vickers method. Data were analyzed with one-way ANOVA and post hoc Tukey tests (P bleaching agents significantly decreased microhardness compared to the control group (P 0.05). Conclusion. Bleaching agents decreased microhardness of silorane-based composite resin restorations, the magnitude of which depending on the bleaching strategy used.

  12. Food Simulating Organic Solvents for Evaluating Crosslink Density of Bulk Fill Composite Resin

    Directory of Open Access Journals (Sweden)

    Neveen M. Ayad

    2017-01-01

    Full Text Available Objectives. To evaluate crosslink densities of two bulk fill composite resins and determine if the used Food Simulating Organic Solvent (FSOS affected them. Methods. Forty specimens were prepared from SureFill and SonicFill bulk fill composite resins, 20 each. All specimens were stored dry for 24 h. Each group was divided into 2 subgroups: stored in ethanol (E 75% or in methyl ethyl ketone (MEK 100% for 24 h. Crosslink density was evaluated by calculating the difference between the Vickers hardness numbers of the specimens stored dry and after their storage in FSOS. The data were statistically analyzed using t-test. Results. The means of crosslink density in E and MEK were 6.99% and 9.44% for SureFill and 10.54% and 11.92% for SonicFill, respectively. t-test displayed significant differences between crosslink densities of SureFill and SonicFill: (P<0.0001 in E and (P=0.02 in MEK and between crosslink densities of SureFill in E and MEK (P=0.02. Conclusions. Crosslink density of bulk fill composite resin can be evaluated using E or MEK. SureFill has higher crosslink density than SonicFill in both E and MEK.

  13. Evaluation of proximal contact tightness of Class II resin composite restorations.

    NARCIS (Netherlands)

    Saber, M.H.; Loomans, B.A.C.; Zohairy, A. El; Dorfer, C.E.; El-Badrawy, W.

    2010-01-01

    OBJECTIVE: The objective of the current study was to compare in-vitro the proximal contact tightness (PCT) of Class II resin composite restorations (RCR) placed with different established and new placement techniques. METHODS: 105 ivorine lower left first molars with standardized MO cavities were

  14. Bacterial viability and physical properties of antibacterially modified experimental dental resin composites.

    Directory of Open Access Journals (Sweden)

    Stefan Rüttermann

    Full Text Available PURPOSE: To investigate the antibacterial effect and the effect on the material properties of a novel delivery system with Irgasan as active agent and methacrylated polymerizable Irgasan when added to experimental dental resin composites. MATERIALS AND METHODS: A delivery system based on novel polymeric hollow beads, loaded with Irgasan and methacrylated polymerizable Irgasan as active agents were used to manufacture three commonly formulated experimental resin composites. The non-modified resin was used as standard (ST. Material A contained the delivery system providing 4 % (m/m Irgasan, material B contained 4 % (m/m methacrylated Irgasan and material C 8 % (m/m methacrylated Irgasan. Flexural strength (FS, flexural modulus (FM, water sorption (WS, solubility (SL, surface roughness Ra, polymerization shrinkage, contact angle Θ, total surface free energy γS and its apolar γS (LW, polar γS (AB, Lewis acid γS (+and base γS (- term as well as bacterial viability were determined. Significance was p < 0.05. RESULTS: The materials A to C were not unacceptably influenced by the modifications and achieved the minimum values for FS, WS and SL as requested by EN ISO 4049 and did not differ from ST what was also found for Ra. Only A had lower FM than ST. Θ of A and C was higher and γS (AB of A and B was lower than of ST. Materials A to C had higher γS (+ than ST. The antibacterial effect of materials A to C was significantly increased when compared with ST meaning that significantly less vital cells were found. CONCLUSION: Dental resin composites with small quantities of a novel antibacterially doped delivery system or with an antibacterial monomer provided acceptable physical properties and good antibacterial effectiveness. The sorption material being part of the delivery system can be used as a vehicle for any other active agent.

  15. Effect of dual-cure composite resin as restorative material on marginal adaptation of class 2 restorations.

    Science.gov (United States)

    Bortolotto, Tissiana; Melian, Karla; Krejci, Ivo

    2013-10-01

    The present study attempted to find a simple direct adhesive restorative technique for the restoration of Class 2 cavities. A self-etch adhesive system with a dual-cured core buildup composite resin (paste 1 + paste 2) was evaluated in its ability to restore proximo-occlusal cavities with margins located on enamel and dentin. The groups were: A, cavity filling (cf) with paste 1 (light-curing component) by using a layering technique; B, cf by mixing both pastes, bulk insertion, and dual curing; and C, cf by mixing both pastes, bulk insertion, and chemical curing. Two control groups (D, negative, bulk; and E, positive, layering technique) were included by restoring cavities with a classic three-step etch-and-rinse adhesive and a universal restorative composite resin. SEM margin analysis was performed before and after thermomechanical loading in a chewing simulator. Percentages (mean ± SD) of "continuous margins" were improved by applying the material in bulk and letting it self cure (54 ± 6) or dual cure (59 ± 9), and no significant differences were observed between these two groups and the positive control (44 ± 19). The present study showed that the dual-cured composite resin tested has the potential to be used as bulk filling material for Class 2 restorations. When used as filling materials, dual-cure composite resins placed in bulk can provide marginal adaptation similar to light-cured composites applied with a complex stratification technique.

  16. Shear-bond-strength of orthodontic brackets to aged nano-hybrid composite-resin surfaces using different surface preparation.

    Science.gov (United States)

    Demirtas, Hatice Kubra; Akin, Mehmet; Ileri, Zehra; Basciftci, Faruk Ayhan

    2015-01-01

    The aim of this study was to evaluate the effects of different surface preparation methods on the shear bond strength (SBS) of orthodontic metal brackets to aged nano-hybrid resin composite surfaces in vitro. A total of 100 restorative composite resin discs, 6 mm in diameter and 3 mm thick, were obtained and treated with an ageing procedure. After ageing, the samples were randomly divided as follows according to surface preparation methods: (1)Control, (2)37% phosphoric acid gel, (3)Sandblasting, (4)Diamond bur, (5)Air-flow and 20 central incisor teeth were used for the control etched group. SBS test were applied on bonded metal brackets to all samples. SBS values and residual adhesives were evaluated. Analysis of variance showed a significant difference (porthodontic metal brackets to nano-hybrid composite resin surfaces.

  17. Non-destructive evaluation of teeth restored with different composite resins using synchrotron based micro-imaging.

    Science.gov (United States)

    Fatima, A; Kulkarni, V K; Banda, N R; Agrawal, A K; Singh, B; Sarkar, P S; Tripathi, S; Shripathi, T; Kashyap, Y; Sinha, A

    2016-01-01

    Application of high resolution synchrotron micro-imaging in microdefects studies of restored dental samples. The purpose of this study was to identify and compare the defects in restorations done by two different resin systems on teeth samples using synchrotron based micro-imaging techniques namely Phase Contrast Imaging (PCI) and micro-computed tomography (MCT). With this aim acquired image quality was also compared with routinely used RVG (Radiovisiograph). Crowns of human teeth samples were fractured mechanically involving only enamel and dentin, without exposure of pulp chamber and were divided into two groups depending on the restorative composite materials used. Group A samples were restored using a submicron Hybrid composite material and Group B samples were restored using a Nano-Hybrid restorative composite material. Synchrotron based PCI and MCT was performed with the aim of visualization of tooth structure, composite resin and their interface. The quantitative and qualitative comparison of phase contrast and absorption contrast images along with MCT on the restored teeth samples shows comparatively large number of voids in Group A samples. Quality assessment of dental restorations using synchrotron based micro-imaging suggests Nano-Hybrid resin restorations (Group B) are better than Group A.

  18. Morphology and contact angle studies of poly(styrene-co-acrylonitrile modified epoxy resin blends and their glass fibre reinforced composites

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available In this study, the surface characteristics of blends and composites of epoxy resin were investigated. Poly(styrene-co-acylonitrile (SAN was used to modify diglycedyl ether of bisphenol-A (DGEBA type epoxy resin cured with diamino diphenyl sulfone (DDS and the modified epoxy resin was used as the matrix for fibre reinforced composites (FRP’s. E-glass fibre was used as the fibre reinforcement. The scanning electron micrographs of the fractured surfaces of the blends and composites were analyzed. Morphological analysis revealed different morphologies such as dispersed, cocontinuous and phase-inverted structures for the blends. Contact angle studies were carried out using water and methylene iodide at room temperature. The solid surface energy was calculated using harmonic mean equations. Blending of epoxy resin increases its contact angle. The surface free energy, work of adhesion, interfacial free energy, spreading coefficient and Girifalco-Good’s interaction parameter were changed significantly in the case of blends and composites. The incorporation of thermoplastic and glass fibre reduces the wetting and hydrophilicity of epoxy resin.

  19. The combined effect of food-simulating solutions, brushing and staining on color stability of composite resins

    Science.gov (United States)

    Silva, Tânia Mara Da; Sales, Ana Luísa Leme Simões; Pucci, Cesar Rogerio; Borges, Alessandra Bühler; Torres, Carlos Rocha Gomes

    2017-01-01

    Abstract Objective: This study evaluated the effect of food-simulating media associated with brushing and coffee staining on color stability of different composite resins. Materials and methods: Eighty specimens were prepared for each composite: Grandio SO (Voco), Amaris (Voco), Filtek Z350XT (3M/ESPE), Filtek P90 (3M/ESPE). They were divided into four groups according to food-simulating media for 7 days: artificial saliva (control), heptane, citric acid and ethanol. The composite surface was submitted to 10,950 brushing cycles (200 g load) in an automatic toothbrushing machine. The specimens were darkened with coffee solution at 37 °C for 24 h. After each treatment, color measurements were assessed by spectrophotometry, using CIE L*a*b* system. The overall color change (ΔE) was determined for each specimen at baseline (C1) and after the treatments (food-simulating media immersion/C2, brushing/C3 and dye solution/C4). Data were analyzed by two-way repeated measures ANOVA and Tukey’s tests (p composites (p = .001), time (p = .001) and chemical degradation (p = .002). The mean of ΔE for composites were: Z350XT (5.39)a, Amaris (3.89)b, Grandio (3.75)bc, P90 (3.36)c. According to food-simulating media: heptane (4.41)a, citric acid (4.24)a, ethanol (4.02)ab, artificial saliva (3.76)b. For the treatments: dye solution (4.53)a, brushing (4.26)a, after food-simulating media (3.52)b. Conclusions: The composite resin Filtek Z350XT showed significantly higher staining than all other composite resin tested. The immersion in heptane and citric acid produced the highest color alteration than other food-simulating media. The exposure of samples to brushing protocols and darkening in coffee solution resulted in significant color alteration of the composite resins. PMID:28642926

  20. High performance thermoplastics: A review of neat resin and composite properties

    Science.gov (United States)

    Johnston, Norman J.; Hergenrother, Paul M.

    1987-01-01

    A review was made of the principal thermoplastics used to fabricate high performance composites. Neat resin tensile and fracture toughness properties, glass transition temperatures (Tg), crystalline melt temperatures (Tm) and approximate processing conditions are presented. Mechanical properties of carbon fiber composites made from many of these thermoplastics are given, including flexural, longitudinal tensile, transverse tensile and in-plane shear properties as well as short beam shear and compressive strengths and interlaminar fracture toughness. Attractive features and problems involved in the use of thermo-plastics as matrices for high performance composites are discussed.

  1. Masking of Enamel Fluorosis Discolorations and Tooth Misalignment With a Combination of At-Home Whitening, Resin Infiltration, and Direct Composite Restorations.

    Science.gov (United States)

    Perdigão, J; Lam, V Q; Burseth, B G; Real, C

    This clinical report illustrates a conservative technique to mask enamel discolorations in maxillary anterior teeth caused by hypomineralization associated with enamel fluorosis and subsequent direct resin composite to improve the anterior esthetics. The treatment consisted of at-home whitening with 10% carbamide peroxide gel with potassium nitrate and sodium fluoride in a custom-fitted tray to mask the brown-stained areas, followed by resin infiltration to mask the white spot areas. An existing resin composite restoration in the maxillary right central incisor was subsequently replaced after completion of the whitening and resin infiltration procedures, whereas the two misaligned and rotated maxillary lateral incisors were built up with direct resin composite restorations to provide the illusion of adequate arch alignment, as the patient was unable to use orthodontic therapy.

  2. High performance thermoplastics - A review of neat resin and composite properties

    Science.gov (United States)

    Johnston, Norman J.; Hergenrother, Paul M.

    1987-01-01

    A review was made of the principal thermoplastics used to fabricate high performance composites. Neat resin tensile and fracture toughness properties, glass transition temperatures (Tg), crystalline melt temperatures (Tm) and approximate processing conditions are presented. Mechanical properties of carbon fiber composites made from many of these thermoplastics are given, including flexural, longitudinal tensile, transverse tensile and in-plane shear properties as well as short beam shear and compressive strengths and interlaminar fracture toughness.

  3. Influence of opalescence and fluorescence properties on the light transmittance of resin composite as a function of wavelength.

    Science.gov (United States)

    Lee, Yong-Keun; Powers, John M

    2006-10-01

    To determine the influence of opalescence and fluorescence properties on the light transmittance of resin composites as a function of wavelength (410-750 nm). Spectral distribution of seven resin composites of A2 shade was measured according to the CIELAB color scale relative to the standard illuminant D65 in the reflectance and transmittance modes. Opalescence spectrum (OPS) was calculated as the subtraction spectrum (i.e., the spectrum measured in the transmittance mode subtracted at each wavelength from the spectrum measured in the reflectance mode). UV component of the illuminant was included and excluded to calculate the fluorescence spectrum (FLR and FLT in the reflectance and transmittance mode, respectively). Contrast ratio (CR) was calculated as the ratio of reflectance over a black background and over a white background. The total transmittance spectral distribution (TSD) value was used as the parameter to indicate masking ability of the resin composites over background color. Multiple regression analyses were performed among TSD and other optical parameters at the significance level of 0.05. In all the resin composites and wavelength range, correlation between CR and TSD was very high (r = -0.99). Correlations between each parameters varied by the wavelength range of fluorescence (410-500 nm) and no-fluorescence (510-750 nm). Correlation between OPS and TSD varied by the wavelength range (r = -0.86 to -0.94, Popalescence and fluorescence of resin composite varied by the wavelength.

  4. Survival Rates from Fracture of Endodontically Treated Premolars Restored with Full-coverage Crowns or Direct Resin Composite Restorations: A Retrospective Study.

    Science.gov (United States)

    Suksaphar, Warattama; Banomyong, Danuchit; Jirathanyanatt, Titalee; Ngoenwiwatkul, Yaowaluk

    2018-02-01

    The aim of the present study was to compare the survival rates against fracture of premolar endodontically treated teeth (ETT) restored with resin composite or crowns and to identify risk factors associated with the fracture. Data from dental records and radiographs of premolar ETT with postendodontic restorations (ie, resin composite or crowns) were collected between 2012 and 2016 and selected following selected inclusion and exclusion criteria. Tooth location, type of restoration, number of proximal contacts, and amount of tooth surface loss were recorded. The incidence and restorability of postendodontic fractures were identified. Survival rates against fracture of the 2 restoration types were calculated using Kaplan-Meier survival analysis. Any potential factors associated with fractures were identified using Cox proportional hazards models. The survival rate against fracture of ETT restored with crowns (95.1%) was higher than resin composite (77.0%). ETT restored with resin composite with 1 or 2 tooth surface losses and 2 proximal contacts had a high survival rate of 88.5% that was not significantly different from ETT with crowns. A higher incidence of restorability after fracture was observed in teeth restored with resin composite than crowns. The type of restoration and number of proximal contacts were identified as potential risk factors associated with fracture incidence. The survival rate against fracture of ETT restored with crowns was higher than resin composite. However, ETT with 1 or 2 tooth surface losses and 2 proximal contacts and restored with resin composite showed a high survival rate that was comparable with ETT restored with crowns. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. The effect of bulk-resin CNT-enrichment on damage and plasticity in shear-loaded laminated composites

    KAUST Repository

    Ventura, Isaac Aguilar

    2013-07-01

    One way to improve multi functionality of epoxy-based laminated composites is to dope the resin with carbon nanotubes. Many investigators have focused on the elastic and fracture behavior of such nano-modified polymers under tensile loading. Yet, in real structural applications, laminated composites can exhibit plasticity and progressive damage initiated mainly by shear loading. We investigated the damage and plasticity induced by the addition of carbon nanotubes to the matrix of a glass fiber/epoxy composite system. We characterized both the modified epoxy resin and the associated modified laminates using classical mesoscale analysis. We used dynamic mechanical analysis, scanning electron microscopy, atomic force microscopy and classical mechanical testing to characterize samples with different concentrations of nanofillers. Since the samples were prepared using the solvent evaporation technique, we also studied the influence of this process. We found that in addition to the global increase in elastic regime properties, the addition of carbon nanotubes also accelerates the damage process in both the bulk resin and its associated glass-fiber composite. © 2013 Elsevier Ltd.

  6. Bond strength of composite resin to enamel: assessment of two ethanol wet-bonding techniques.

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2014-04-01

    Full Text Available Ethanol wet-bonding (EWB technique has been stated to decrease degradation of resin-dentin bond. This study evaluated the effect of two EWB techniques on composite resin-to-enamel bond strength.Silicon carbide papers were used to produce flat enamel surfaces on the buccal faces of forty-five molars. OptiBond FL (OFL adhesive was applied on enamel surfaces in three groups of 15 namely: Enamel surface and OFL (control;Protocol 1 of the EWB technique: absolute ethanol was applied to water-saturated acid-etched enamel surfaces for 1 minute before the application of ethanol-solvated hydrophobic adhesive resin of OFL 3 times;Protocol 2: progressive ethanol replacement; water was gradually removed from the enamel matrix using ascending ethanol concentrations before OFL application. Composite build-ups were made and the specimens were stored for 24 hours at 37°C and 100% relative humidity. Shear bond strength test was performed using a universal testing machine at 1 mm/min crosshead speed. Fracture patterns were evaluated microscopically. Data were analyzed with one-way ANOVA and Fisher's exact test (α=0.05.There were no significant differences in bond strength between the groups (P=0.73. However, regarding failure patterns, the highest cohesive enamel fractures were recorded in groups 2 and 3.In this study, although both methods of EWB did not influence immediate bond strength of composite resin to enamel, the majority of failure patterns occurred cohesively in enamel.

  7. Treatment planning and smile design using composite resin.

    Science.gov (United States)

    Marus, Robert

    2006-05-01

    Recent advances in dental materials and adhesive protocols have expanded the restorative procedures available to today's clinicians. Used in combination with proper treatment planning, these innovations enable dental professionals to provide enhanced aesthetic care that achieves the increasing expectations of their patients. Using a case presentation, this article will document the steps required to harmoniously integrate smile design, material selection, and patient communication that are involved in the provisional of aesthetic dental care. This article discusses the utilization of composite resin as a tool to enhance the patient's smile. Upon reading this article, the reader should: Become familiar with a smile-enhancing technique which can be completed in one office visit. Realize the benefits that intraoral composite mockups offer in terms of prototyping and confirming patient satisfaction.

  8. Study on polyethylene glycol/epoxy resin composite as a form-stable phase change material

    International Nuclear Information System (INIS)

    Fang Yutang; Kang Huiying; Wang Weilong; Liu Hong; Gao Xuenong

    2010-01-01

    Form-stable polyethylene glycol (PEG)/epoxy resin (EP) composite as a novel phase change material (PCM) was prepared using casting molding method. In this new material, PEG acts as the latent heat storage material and EP polymer serves as the supporting material, which provides structural strength and prevents the leakage of the melted PEG. The structure and morphology of the novel composite were observed using Fourier transformation infrared spectroscope (FTIR) and scanning electronic microscope (SEM). The thermo-mechanical property and transition behavior were characterized by polarizing optical microscope (POM), static thermo-mechanical analysis (TMA) and differential scanning calorimeter (DSC). The experimental results show that, as a result of the physical tangled function of the epoxy resin carrier to the PEG segment, the composite macroscopically presents the solid-solid phase change characteristic.

  9. Friction and wear behavior of nanosilica-filled epoxy resin composite coatings

    International Nuclear Information System (INIS)

    Kang Yingke; Chen Xinhua; Song Shiyong; Yu Laigui; Zhang Pingyu

    2012-01-01

    Hydrophilic silica nanoparticles (abridged as nano-SiO 2 ) surface-capped with epoxide were dispersed in the solution of epoxy resin (abridged as EP) in tetrahydrofuran under magnetic stirring. Resultant suspension of nano-SiO 2 in EP was then coated onto the surface of glass slides and dried at 80 °C in a vacuum oven for 2 h, generating epoxy resin-nanosilica composite coatings (coded as EP/nano-SiO 2 ). EP coating without nano-SiO 2 was also prepared as a reference in the same manner. A water contact angle meter and a surface profiler were separately performed to measure the water contact angles and surface roughness of as-prepared EP/nano-SiO 2 composite coatings. The friction and wear behavior of as-prepared EP/nano-SiO 2 composite coatings sliding against steel in a ball-on-plate contact configuration under unlubricated condition was evaluated. Particularly, the effect of coating composition on the friction and wear behavior of the composite coatings was highlighted in relation to their microstructure and worn surface morphology examined by means of scanning electron microscopy. Results indicate that EP/nano-SiO 2 composite coatings have a higher surface roughness and water contact angle than EP coating. The EP-SiO 2 coatings doped with a proper amount of hydrophilic SiO 2 nanoparticles show lower friction coefficient than EP coating. However, the introduction of surface-capped nanosilica as the filler results in inconsistent change in the friction coefficient and wear rate of the filled EP-matrix composites; and it needs further study to achieve well balanced friction-reducing and antiwear abilities of the composite coatings for tribological applications.

  10. Laminated composite based on polyester geotextile fibers and polyurethane resin for coating wood structures

    Directory of Open Access Journals (Sweden)

    Yuri Andrey Olivato Assagra

    2013-01-01

    Full Text Available New environmental laws have restricted the use of hardwood trees in overhead power lines structures, such as, poles and cross-arms, leading companies to seek alternative materials. Reforested wood coated with polymeric resin has been proposed as an environmental friendly solution, with improved electrical properties and protection against external agents, e.g. moisture, ultraviolet radiation and fungi. However, the single thin layer of resin, normally applied on such structures reveal to be inefficient, due to be easily damage during handling. In this paper, we present a composite coating, based on geotextile fibers and polyurethane resin that is suitable for wooden structures. Results obtained from two different tree species (from managed and reforested areas coated with the composite reveal that the additional layer not only provided a stronger adhesion between wood and ccoating layer but also a further improvement in the electrical properties and better protection against abrasion and moisture.

  11. Deposition of lead and cadmium released by cigarette smoke in dental structures and resin composite.

    Science.gov (United States)

    Takeuchi, Cristina Yoshie Garcia; Corrêa-Afonso, Alessandra Marques; Pedrazzi, Hamilton; Dinelli, Welingtom; Palma-Dibb, Regina Guenka

    2011-03-01

    Cigarette smoke is a significant source of cadmium, lead, and toxic elements, which are absorbed into the human organism. In this context, the aim of this study was to investigate in vitro the presence of toxic elements, cadmium, and lead deriving from cigarette smoke in the resin composite, dentine, and dental enamel. Eight cylindrical specimens were fabricated from resin composite, bovine enamel, and root dentin fragments that were wet ground and polished with abrasive paper to obtain sections with 6-mm diameter and 2-mm thickness. All specimens were exposed to the smoke of 10 cigarettes/day during 8 days. After the simulation of the cigarette smoke, the specimens were examined with scanning electron microscopy (SEM) and the energy-dispersive X-ray analysis. In the photomicrographic analysis in SEM, no morphological alterations were found; however, the microanalysis identified the presence of cadmium, arsenic, and lead in the different specimens. These findings suggest that the deposition of these elements derived from cigarette smoke could be favored by dental structures and resin composite. Copyright © 2010 Wiley-Liss, Inc.

  12. Polymerization shrinkage of different types of composite resins and microleakage with and without liner in class II cavities.

    Science.gov (United States)

    Karaman, E; Ozgunaltay, G

    2014-01-01

    To determine the volumetric polymerization shrinkage of four different types of composite resin and to evaluate microleakage of these materials in class II (MOD) cavities with and without a resin-modified glass ionomer cement (RMGIC) liner, in vitro. One hundred twenty-eight extracted human upper premolar teeth were used. After the teeth were divided into eight groups (n=16), standardized MOD cavities were prepared. Then the teeth were restored with different resin composites (Filtek Supreme XT, Filtek P 60, Filtek Silorane, Filtek Z 250) with and without a RMGIC liner (Vitrebond). The restorations were finished and polished after 24 hours. Following thermocycling, the teeth were immersed in 0.5% basic fuchsin for 24 hours, then midsagitally sectioned in a mesiodistal plane and examined for microleakage using a stereomicroscope. The volumetric polymerization shrinkage of materials was measured using a video imaging device (Acuvol, Bisco, Inc). Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney U-tests. All teeth showed microleakage, but placement of RMGIC liner reduced microleakage. No statistically significant differences were found in microleakage between the teeth restored without RMGIC liner (p>0.05). Filtek Silorane showed significantly less volumetric polymerization shrinkage than the methacrylate-based composite resins (pcomposite resin restorations resulted in reduced microleakage. The volumetric polymerization shrinkage was least with the silorane-based composite.

  13. Polymer-inorganic composite resins for recovery of radioactive cesium from acidic media

    International Nuclear Information System (INIS)

    Park, J.I.; Kim, J.S.; Jo, A.; Jang, E.; Park, Y.J.

    2014-01-01

    In this work, our objectives are as follow: i) the development of a method to produce polymer-ammonium molybdophosphate composite resins with the size range ideal for column operations, ii) the preparation of a different type of polymer-AMP granules, other than polyacrylonitrile, with good physical and chemical stability, and iii) the investigation of sorption and recovery properties of the composite potentially useful for radioactive cesium. (author)

  14. Study of a composite from reactive blending of methylol urea resin ...

    African Journals Online (AJOL)

    This study was designed to study some physical properties of a composite derivable from reactive blending of methylol urea resin (MUR) with natural rubber (NR). Formaldehyde emission, decreased with increase in NR concentration in the blend. Elongation at break and viscosity recorded an initial increase but gradually ...

  15. A comparative evaluation of the staining capacity of microhybrid and nanohybrid resin-based composite to indian spices and food colorants: An In vitro study.

    Science.gov (United States)

    Usha, Carounanidy; Rao, Sathyanarayanan Rama; George, Geena Mary

    2018-01-01

    Resin composite restorative materials can mimic the natural color and shade of the tooth. However, exogenous colorants from food and drinks can stain them due to adsorption. The influence of Indian food colorants and spices on resin composite restorations has not been evaluated extensively. This study aims to evaluate the staining capacity of microhybrid and nanohybrid resin-based composites, to saffron extract, tandoori powder, and turmeric powder. Forty samples of microhybrid (Kulzer Charisma) and nanohybrid (3M Filtek Z350) resin composites were prepared using an acrylic template of dimension 5 mm × 3 mm. They were randomly divided into four groups and immersed into solutions of saffron extract, tandoori powder, and turmeric powder. Distilled water was used as the control group. Color values (LFNx01, aFNx01, bFNx01) were measured by colorimeter using the CIE LFNx01aFNx01bFNx01 system before and after 72 h of immersion. Color differences ΔEFNx01ab were statistically analyzed. Two-way ANOVA and post-hoc Tukey (honest significant difference) test were done using IBM SPSS Statistics for Windows, Version 19.0. Armonk, NY: IBM Corp. : All the immersion media changed the color of the resin composites to varying degrees. However, turmeric solution showed the maximum mean color variation ΔEFNx01ab of 14.8 ± 2.57 in microhybrid resin composites and 16.8 ± 3.50 in nanohybrid resin composites. Microhybrid and nanohybrid resin composites tend to stain to Indian food colorants, especially to turmeric powder.

  16. Annealing effects of carbon fiber-reinforced epoxy resin composites irradiated by electron beams

    International Nuclear Information System (INIS)

    Udagawa, Akira; Sasuga, Tuneo; Ito, Hiroshi; Hagiwara, Miyuki

    1987-01-01

    Carbon cloth-reinforced epoxy resin composites were irradiated with 2 MeV electrons at room temperature and then annealed in air for 2 h at temperatures up to 180 deg C. A considerable decrease in the three-point bending strength occurred when the irradiated composites were annealed in the temperature range of 115 - 135 deg C which is below the glass transition temperature T g of the matrix resin, while the bending strength remained unchanged up to 180 deg C for the unirradiated composites. In the dynamic viscoelastic spectra of the irradiated matrix, a new relaxation appeared at the temperature extending from 50 deg C to just below the matrix T g and disappeared on annealing for 2 h at 135 deg C. Annealing also decreased the concentration of free radicals existing stably in the irradiated matrix at room temperature. After annealing, a large amount of clacks and voids were observed in the fractography of the composites by scanning electron microscopy. These results indicate: (1) Annealing brings about rearrangement of the radiation-induced molecular chain scission in the matrix; (2) The bending strength of the irradiated composites decreased owing to the increased brittleness of the matrix by annealing. (author)

  17. Leaching of iodine from composites based on epoxy resin and lead iodide

    International Nuclear Information System (INIS)

    Kalinin, N.N.; Elizarova, A.N.

    1988-01-01

    The scope for using solid composites obtained by incorporating dry powdery lead iodide and its aqueous suspension into epoxy resin for prolonged immobilization of iodine-129 under monitorable storage conditions has been assessed by a study of leaching of iodine

  18. Evaluation of the filler packing structures in dental resin composites: From theory to practice.

    Science.gov (United States)

    Wang, Ruili; Habib, Eric; Zhu, X X

    2018-07-01

    The aim of this study is to evaluate the packing properties of uniform silica particles and their mixture with secondary particles yielding maximally loaded dental composites. We intend to verify the difference between the idealized models (the close-packed structures and the random-packed structures) and the actual experimental results, in order to provide guidance for the preparation of dental composites. The influence of secondary particle size and the resin composition on the physical-mechanical properties and the rheological properties of the experimental dental composites was also investigated. Silica particles (S-920, S-360, and S-195) with average diameters of 920, 360, and 195nm were synthesized via the Stöber process. Their morphology and size distribution were determined by field-emission scanning electron microscopy and laser particle sizer. A series of silica fillers, S-920, S-920+195, S-920+360, and S-920+360+195, were then formulated with two Bis-GMA/TEGDMA resins (weight ratios of 70:30 and 50:50). For these experimental dental composites, their maximum filler loadings were assessed and compared to the theory. The mechanical properties, degree of conversion, depth of cure, and polymerization shrinkage of these composites were then evaluated. Their rheological behaviors were measured with a rheometer. Unimodal S-920 had the maximally filler loading of 70.80wt% with the 5B5T resin, close to the theoretical estimation of the random loose packing (71.92wt%). The maximum loading of the S-920+360+195 filled composite was 72.92wt% for the same resin, compared to the theoretical estimation of 89.29wt% obtained for the close-packed structures. These findings indicate that random loose packing matches more closely to the real packing state for the filler formulations used. When maximally loaded, the composite with S-920+360+195 produced the best mechanical properties and the lowest polymerization shrinkage. The degree of conversion and depth of cure were

  19. Study of the chemical composition of the resinous exudate isolated from Heliotropium sclerocarpum and evaluation of the antioxidant properties of the phenolic compounds and the resin.

    Science.gov (United States)

    Modak, Brenda; Salina, Melissa; Rodilla, Jesús; Torres, René

    2009-11-12

    Heliotropium sclerocarpum Phil. (Heliotropiaceae) is a resinous bush that grows in the Atacama of northern Chile. The chemical composition of its resinous exudate was analyzed for the first time. One aromatic geranyl derivative: filifolinol (1), one flavanone: naringenin (2) and a new type of 3-oxo-2-arylbenzofuran derivative 3 were isolated and their structures were determined. The antioxidant activity of the phenolic compounds and resin was evaluated using the bleaching of DPPH radical method and expressed as fast reacting equivalents (FRE) and total reacting equivalents (TRE).

  20. Cure Cycle Design Methodology for Fabricating Reactive Resin Matrix Fiber Reinforced Composites: A Protocol for Producing Void-free Quality Laminates

    Science.gov (United States)

    Hou, Tan-Hung

    2014-01-01

    For the fabrication of resin matrix fiber reinforced composite laminates, a workable cure cycle (i.e., temperature and pressure profiles as a function of processing time) is needed and is critical for achieving void-free laminate consolidation. Design of such a cure cycle is not trivial, especially when dealing with reactive matrix resins. An empirical "trial and error" approach has been used as common practice in the composite industry. Such an approach is not only costly, but also ineffective at establishing the optimal processing conditions for a specific resin/fiber composite system. In this report, a rational "processing science" based approach is established, and a universal cure cycle design protocol is proposed. Following this protocol, a workable and optimal cure cycle can be readily and rationally designed for most reactive resin systems in a cost effective way. This design protocol has been validated through experimental studies of several reactive polyimide composites for a wide spectrum of usage that has been documented in the previous publications.

  1. Optimal Design for Hybrid Ratio of Carbon/Basalt Hybrid Fiber Reinforced Resin Matrix Composites

    Directory of Open Access Journals (Sweden)

    XU Hong

    2017-08-01

    Full Text Available The optimum hybrid ratio range of carbon/basalt hybrid fiber reinforced resin composites was studied. Hybrid fiber composites with nine different hybrid ratios were prepared before tensile test.According to the structural features of plain weave, the unit cell's performance parameters were calculated. Finite element model was established by using SHELL181 in ANSYS. The simulated values of the sample stiffness in the model were approximately similar to the experimental ones. The stress nephogram shows that there is a critical hybrid ratio which divides the failure mechanism of HFRP into single failure state and multiple failure state. The tensile modulus, strength and limit tensile strain of HFRP with 45% resin are simulated by finite element method. The result shows that the tensile modulus of HFRP with 60% hybrid ratio increases by 93.4% compared with basalt fiber composites (BFRP, and the limit tensile strain increases by 11.3% compared with carbon fiber composites(CFRP.

  2. Heat treatment of a direct composite resin: influence on flexural strength

    Directory of Open Access Journals (Sweden)

    Caroline Lumi Miyazaki

    2009-09-01

    Full Text Available The purpose of this study was to evaluate the flexural strength of a direct composite, for indirect application, that received heat treatment, with or without investment. One indirect composite was used for comparison. For determination of the heat treatment temperature, thermogravimetric analysis (TGA and differential scanning calorimetry (DSC were performed, considering the initial weight loss temperature and glass transition temperature (Tg. Then, after photoactivation (600 mW/cm² - 40 s, the specimens (10 x 2 x 2 mm were heat-treated following these conditions: 170ºC for 5, 10 or 15 min, embedded or not embedded in investment. Flexural strength was assessed as a means to evaluate the influence of different heat treatment periods and investment embedding on mechanical properties. The data were analyzed by ANOVA and Tukey's test (α = 0.05. TGA showed an initial weight loss temperature of 180ºC and DSC showed a Tg value of 157°C. Heat treatment was conducted in an oven (Flli Manfredi, Italy, after 37°C storage for 48 h. Flexural strength was evaluated after 120 h at 37°C storage. The results showed that different periods and investment embedding presented similar statistical values. Nevertheless, the direct composite resin with treatments presented higher values (178.7 MPa compared to the indirect composite resin (146.0 MPa and the same direct composite submitted to photoactivation only (151.7 MPa. Within the limitations of this study, it could be concluded that the heat treatment increased the flexural strength of the direct composite studied, leading to higher mechanical strength compared to the indirect composite.

  3. Effects of roughness on interfacial performances of silica glass and non-polar polyarylacetylene resin composites

    International Nuclear Information System (INIS)

    Jiang, Z.X.; Huang, Y.D.; Liu, L.; Long, J.

    2007-01-01

    The influence of roughness on interfacial performances of silica glass/polyarylacetylene resin composites was investigated. In order to obtain different roughness, silica glass surface was abraded by different grits of abrasives and its topography was observed by scanning electron microscopy and atomic force microscopy. At the same time, the failure mechanisms of composites were analyzed by fracture morphologies and the interfacial adhesion was evaluated by shear strength test. The results indicated that shear strength of silica glass/polyarylacetylene resin composites firstly increased and then decreased with the surface roughness of silica glass increased. The best surface roughness range of silica glass was 40-60 nm. The main mechanism for the improvement of the interfacial adhesion was physical interlocking at the interface

  4. Cytotoxic evaluation of hydroxyapatite-filled and silica/hydroxyapatite-filled acrylate-based restorative composite resins: An in vitro study.

    Science.gov (United States)

    Chadda, Harshita; Naveen, Sangeetha Vasudevaraj; Mohan, Saktiswaren; Satapathy, Bhabani K; Ray, Alok R; Kamarul, Tunku

    2016-07-01

    Although the physical and mechanical properties of hydroxyapatite-filled dental restorative composite resins have been examined, the biocompatibility of these materials has not been studied in detail. The purpose of this in vitro study was to analyze the toxicity of acrylate-based restorative composite resins filled with hydroxyapatite and a silica/hydroxyapatite combination. Five different restorative materials based on bisphenol A-glycidyl methacrylate (bis-GMA) and tri-ethylene glycol dimethacrylate (TEGDMA) were developed: unfilled (H0), hydroxyapatite-filled (H30, H50), and silica/hydroxyapatite-filled (SH30, SH50) composite resins. These were tested for in vitro cytotoxicity by using human bone marrow mesenchymal stromal cells. Surface morphology, elemental composition, and functional groups were determined by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier-transformed infrared spectroscopy (FTIR). The spectra normalization, baseline corrections, and peak integration were carried out by OPUS v4.0 software. Both in vitro cytotoxicity results and SEM analysis indicated that the composite resins developed were nontoxic and supported cell adherence. Elemental analysis with EDX revealed the presence of carbon, oxygen, calcium, silicon, and gold, while the presence of methacrylate, hydroxyl, and methylene functional groups was confirmed through FTIR analysis. The characterization and compatibility studies showed that these hydroxyapatite-filled and silica/hydroxyapatite-filled bis-GMA/TEGDMA-based restorative composite resins are nontoxic to human bone marrow mesenchymal stromal cells and show a favorable biologic response, making them potential biomaterials. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  5. Mechanical properties of composites based on unsaturated polyester resins obtained by chemical recycling of poly(ethylene terephthalate

    Directory of Open Access Journals (Sweden)

    Marinković Aleksandar D.

    2013-01-01

    Full Text Available Composites based on unsaturated polyester (UPe resins and fumed silica AEROSIL® RY 50, NY 50, RX 50 and NAX 50, as well as graphite, TiO2 or organically modified clay CLOISITE 30B were prepared in order to investigate the influence of reinforcing agents on the mechanical properties of composites. Unsaturated polyester resins were synthesized from maleic anhydride and products of glycolysis, obtained by depolymerization of poly(ethylene terephthalate with dipropylene glycol (UPe1 resin and triethylene glycol (UPe2 resin in the presence of tetrabutyl titanate catalyst. The obtained unsaturated polyesters were characterized by FTIR spectroscopy, acid and hydroxyl values, and their mechanical properties were also examined. Significant increase of the tensile modulus, tensile strength and decrease of the elongation at break was observed for composites prepared after addition of 10 wt.% of graphite or 10 wt.% of TiO2 to the UPe resins, indicating strong interaction between matrix and filler particles. On the other hand, nanocomposites prepared using UPe2 and hydrophobically modified silica nanoparticles showed lower tensile strength and tensile modulus than polymer matrix. The presence of CLOISITE 30B had no significant influence on the mechanical properties of UPe1, while tensile strength and tensile modulus of UPe2 increased after adding 10 wt.% of clay. [Projekat Ministarstva nauke Republike Srbije, br. 172013

  6. Effect of various infection-control methods for light-cure units on the cure of composite resins.

    Science.gov (United States)

    Chong, S L; Lam, Y K; Lee, F K; Ramalingam, L; Yeo, A C; Lim, C C

    1998-01-01

    This study (1) compared the curing-light intensity with various barrier infection-control methods used to prevent cross contamination, (2) compared the Knoop hardness value of cured composite resin when various barrier control methods were used, and (3) correlated the hardness of the composite resin with the light-intensity output when different infection-control methods were used. The light-cure unit tips were covered with barriers, such as cellophane wrap, plastic gloves, Steri-shields, and finger cots. The control group had no barrier. Composite resins were then cured for each of the five groups, and their Knoop hardness values recorded. The results showed that there was significant statistical difference in the light-intensity output among the five groups. However, there was no significant statistical difference in the Knoop hardness values among any of the groups. There was also no correlation between the Knoop hardness value of the composite resin with the light-intensity output and the different infection-control methods. Therefore, any of the five infection-control methods could be used as barriers for preventing cross-contamination of the light-cure unit tip, for the light-intensity output for all five groups exceeded the recommended value of 300 W/m2. However, to allow a greater margin of error in clinical situations, the authors recommend that the plastic glove or the cellophane wrap be used to wrap the light-cure tip, since these barriers allowed the highest light-intensity output.

  7. Effect of Artificial Aging Protocols on Surface Gloss of Resin Composites

    OpenAIRE

    Rocha, Rafael Santos; Oliveira, Amanda Carvalho; Caneppele, Taciana Marco Ferraz; Bresciani, Eduardo

    2017-01-01

    The purpose of this study was to evaluate the effect of aging protocols on surface gloss of composites. Cylindrical resin composite specimens (6?mm in diameter, 1?mm thick) were fabricated and divided into three groups (N = 60): microfilled (MiFi), nanohybrid (NaHy), and nanofilled (NaFi). Specimens were distributed into four aging subgroups: thermocycling (5? to 55?C, 15,000 cycles); ethanol immersion (15 days); brushing (10,750 cycles); and light aging (216?h). Surface gloss readings (Novo-...

  8. Possible mechanisms for the interaction of polymeric composite resins with Cu(II) ions in aqueous solution

    International Nuclear Information System (INIS)

    El-Zahhhar, A.A.; Abdel-Aziz, H.M.; Siyam, T.

    2005-01-01

    The interaction between the active groups of polymeric composite resins such as Poly(acrylamide-acrylic acid)-ethylenediaminetetra acetic acid disodium salt P(AM-AA)EDTANa 2 , Poly(acrylamide-acrylic acid)- montmorillonite P(AM-AA)-montmorillonite, and Poly(acrylamide-acrylic acid)-potassium nickel hexacyanoferrate P(AM-AA)-KNiHCF, with copper sulfate as a test ion has been studied. The spectroscopic studies show that the mechanism of interaction between polymeric composite resins and copper sulfate is a bond formation between the active groups of polymeric chains and copper ion. The bond formation depends on nature of polymeric chains. It was also found that the amide groups form complexes with hydrated cations, while carboxylate group interact by ion exchange mechanism through complex formation. Montmorillonite and hexacyanoferrate of the resins interact with metal ions by ion exchange mechanism

  9. Effect of two lasers on the polymerization of composite resins: single vs combination.

    Science.gov (United States)

    Ro, Jung-Hoon; Son, Sung-Ae; Park, Jeong-kil; Jeon, Gye-Rok; Ko, Ching-Chang; Kwon, Yong Hoon

    2015-07-01

    The selection of a light-curing unit for the curing composite resins is important to achieve best outcomes. The purpose of the present study was to test lasers of 457 and 473 nm alone or in combination under different light conditions with respect to the cure of composite resins. Four different composite resins were light cured using five different laser combinations (530 mW/cm(2) 457 nm only, 530 mW/cm(2) 473 nm only, 177 mW/cm(2) 457 + 177 mW/cm(2) 473 nm, 265 mW/cm(2) 457 + 265 mW/cm(2) 473 nm, and 354 mW/cm(2) 457 + 354 mW/cm(2) 473 nm). Microhardness and polymerization shrinkage were evaluated. A light-emitting diode (LED) unit was used for comparison purposes. On top surfaces, after aging for 24 h, microhardness achieved using the LED unit and the lasers with different conditions ranged 42.4-65.5 and 38.9-67.7 Hv, respectively, and on bottom surfaces, corresponding ranges were 25.2-56.1 and 18.5-55.7 Hv, respectively. Of the conditions used, 354 mW/cm(2) 457 nm + 354 mW/cm(2) 473 nm produced the highest bottom microhardness (33.8-55.6 Hv). On top and bottom surfaces, microhardness by the lowest total light intensity, 354 (177 × 2) mW/cm(2), ranged 39.0-60.5 and 18.5-52.8 Hv, respectively. Generally, 530 mW/cm(2) at 457 nm produced the lowest polymerization shrinkage. However, shrinkage values obtained using all five laser conditions were similar. The study shows the lasers of 457 and 473 nm are useful for curing composite resins alone or in combination at much lower light intensities than the LED unit.

  10. Evaluation of bisphenol E cyanate ester for the resin-injection repair of advanced composites

    Energy Technology Data Exchange (ETDEWEB)

    Lio, Wilber Yaote [Iowa State Univ., Ames, IA (United States)

    2009-12-01

    This thesis is a compilation of a general introduction and literature review that ties together the subsequent chapters which consist of two journal articles that have yet to be submitted for publication. The overall topic relates to the evaluation and application of a new class of cyanate ester resin with unique properties that lend it applicable to use as a resin for injection repair of high glass transition temperature polymer matrix composites. The first article (Chapter 2) details the evaluation and optimization of adhesive properties of this cyanate ester and alumina nanocomposites under different conditions. The second article (Chapter 3) describes the development and evaluation of an injection repair system for repairing delaminations in polymer matrix composites.

  11. Cosmetic Remodeling of the Smile: Combining Composite Resin and Ceramics over Teeth and Implants

    Directory of Open Access Journals (Sweden)

    Leonardo Fernandes da Cunha

    2017-01-01

    Full Text Available The aim of this paper is to describe a restorative approach to the cosmetic remodeling of the teeth of a young adult patient with right maxillary lateral hypodontia and left lateral microdontia. A conservative restorative management was proposed to improve smile esthetics by combining direct composite resins and ceramics. Initially, periodontal therapy and dental bleaching were performed. Subsequently, direct composite resins were applied to the central incisors and canines to reestablish the sizes and shapes of these teeth. Finally, ceramics were placed on the implant and the microdontia to unite with the new alignment and color of the anterior teeth. Thus, conservative remodeling to improve the harmony of the smile was provided.

  12. Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Valdirene Aparecida [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil); Folgueras, Luiza de Castro; Candido, Geraldo Mauricio; Paula, Adriano Luiz de; Rezende, Mirabel Cerqueira, E-mail: mirabelmcr@iae.cta.br [Instituto de Aeronautica e Espaco (IAE), Sao Jose dos Campos, SP (Brazil). Div. de Materiais; Costa, Michelle Leali [Universidade Estadual Paulista Julio de Mesquita Filho (DMT/UNESP), Guaratingueta, SP (Brazil). Dept. de Materiais e Tecnologia

    2013-07-01

    Nanostructured polymer composites have opened up new perspectives for multifunctional materials. In particular, carbon nanotubes (CNTs) present potential applications in order to improve mechanical and electrical performance in composites with aerospace application. The combination of epoxy resin with multi walled carbon nanotubes results in a new functional material with enhanced electromagnetic properties. The objective of this work was the processing of radar absorbing materials based on formulations containing different quantities of carbon nanotubes in an epoxy resin matrix. To reach this objective the adequate concentration of CNTs in the resin matrix was determined. The processed structures were characterized by scanning electron microscopy, rheology, thermal and reflectivity in the frequency range of 8.2 to 12.4 GHz analyses. The microwave attenuation was up to 99.7%, using only 0.5% (w/w) of CNT, showing that these materials present advantages in performance associated with low additive concentrations (author)

  13. Epoxy Resin Based Composites, Mechanical and Tribological Properties: A Review

    Directory of Open Access Journals (Sweden)

    S.A. Bello

    2015-12-01

    Full Text Available High fuel consumption by automobile and aerospace vehicles built from legacy alloys has been a great challenge to global design and material engineers. This has called for researches into material development for the production of lighter materials of the same or even superior mechanical properties to the existing materials in this area of applications. This forms a part of efforts to achieve the global vision 2025 i.e to reduce the fuel consumption by automobile and aerospace vehicles by at least 75 %. Many researchers have identified advanced composites as suitable materials in this regard. Among the common matrices used for the development of advanced composites, epoxy resin has attained a dominance among its counterparts because of its excellent properties including chemical, thermal and electrical resistance properties, mechanical properties and dimensional stability. This review is a reflection of the extensive study on the currently ongoing research aimed at development of epoxy resin hybrid nanocomposites for engineering applications. In this paper, brief explanation has been given to different terms related to the research work and also, some previous works (in accordance with materials within authors’ reach in the area of the ongoing research have been reported.

  14. Study of the Chemical Composition of the Resinous Exudate Isolated from Heliotropium Sclerocarpum and Evaluation of the Antioxidant Properties of the Phenolic Compounds and the Resin

    Directory of Open Access Journals (Sweden)

    René Torres

    2009-11-01

    Full Text Available Heliotropium sclerocarpum Phil. (Heliotropiaceae is a resinous bush that grows in the Atacama of northern Chile. The chemical composition of its resinous exudate was analyzed for the first time. One aromatic geranyl derivative: filifolinol (1, one flavanone: naringenin (2 and a new type of 3-oxo-2-arylbenzofuran derivative 3 were isolated and their structures were determined. The antioxidant activity of the phenolic compounds and resin was evaluated using the bleaching of DPPH radical method and expressed as fast reacting equivalents (FRE and total reacting equivalents (TRE.

  15. Accelerated Fatigue Resistance of Thick CAD/CAM Composite Resin Overlays Bonded with Light- and Dual-polymerizing Luting Resins.

    Science.gov (United States)

    Goldberg, Jack; Güth, Jan-Frederik; Magne, Pascal

    To evaluate the accelerated fatigue resistance of thick CAD/CAM composite resin overlays luted with three different bonding methods. Forty-five sound human second mandibular molars were organized and distributed into three experimental groups. All teeth were restored with a 5-mm-thick CAD/CAM composite resin overlay. Group A: immediate dentin sealing (IDS) with Optibond FL and luted with light-polymerizing composite (Herculite XRV). Group B: IDS with Optibond FL and luted with dual-polymerizing composite (Nexus 3). Group C: direct luting with Optibond FL and dual-polymerizing composite (Nexus 3). Masticatory forces at a frequency of 5 Hz were simulated using closed-loop servo-hydraulics and forces starting with a load of 200 N for 5000 cycles, followed by steps of 400, 600, 800, 1000, 1200 and 1400 N for a maximum of 30,000 cycles. Each step was applied through a flat steel cylinder at a 45-degree angle under submerged conditions. The fatigue test generated one failure in group A, three failures in group B, and no failures in group C. The survival table analysis for the fatigue test did not demonstrate any significant difference between the groups (p = 0.154). The specimens that survived the fatigue test were set up for the load-to-failure test with a limit of 4600 N. The survival table analysis for the load-to-failure test demonstrates an average failure load of 3495.20 N with survival of four specimens in group A, an average failure load of 4103.60 N with survival of six specimens in group B, and an average failure load of 4075.33 N with survival of nine specimens in group C. Pairwise comparisons revealed no significant differences (p composites in combination with IDS are not contraindicated with thick restorations.

  16. Simulation of Air Entrapment and Resin Curing During Manufacturing of Composite Cab Front by Resin Transfer Moulding Process

    Directory of Open Access Journals (Sweden)

    Kuppusamy Raghu Raja Pandiyan

    2017-09-01

    Full Text Available Mould filling and subsequent curing are the significant processing stages involved in the production of a composite component through Resin Transfer Moulding (RTM fabrication technique. Dry spot formation and air entrapment during filling stage caused by improper design of filling conditions and locations that lead to undesired filling patterns resulting in defective RTM parts. Proper placement of inlet ports and exit vents as well as by adjustment of filling conditions can alleviate the problems during the mould filling stage. The temperature profile used to polymerize the resin must be carefully chosen to reduce the cure time. Instead of trial and error methods that are expensive, time consuming, and non-optimal, we propose a simulation-based optimization strategy for a composite cab front component to reduce the air entrapment and cure stage optimization. In order to be effective, the optimization strategy requires an accurate simulation of the process utilizing submodels to describe the raw material characteristics. Cure reaction kinetics and chemo-rheology were the submodels developed empirically for an unsaturated polyester resin using experimental data. The simulations were performed using commercial software PAM RTM 2008, developed by ESI Technologies. Simulation results show that the use of increase in injection pressure at the inlet filling conditions greatly reduce the air entrapped. For the cab front, the alteration of injection pressure with proper timing of vent opening reduced the air entrapped during mould filling stage. Similarly, the curing simulation results show that the use of higher mould temperatures effectively decreases the cure time as expected.

  17. Randomized controlled split-mouth clinical trial of direct laminate veneers with two micro-hybrid resin composites

    NARCIS (Netherlands)

    Gresnigt, Marco M. M.; Kalk, Warner; Ozcan, M.; Ozcan, Mutlu

    Objectives: This randomized, split-mouth clinical study evaluated the survival rate of direct laminate veneers made of two resin-composite materials. Methods: A total of 23 patients (mean age: 52.4 years old) received 96 direct composite laminate veneers using two micro-hybrid composites in

  18. Preparation and Characterization of UPR/ LNR/ Glass Fiber Composite by using Unsaturated Polyester Resin (PET) from PET Wastes

    International Nuclear Information System (INIS)

    Siti Farhana Hisham; Ishak Ahmad; Rusli Daik

    2011-01-01

    UPR/ LNR/ glass fibre composite had been prepared by using unsaturated polyester resin (UPR) based from recycled PET product. PET waste was recycled by glycolysis process and the glycides product was then reacted with maleic anhydride to produce unsaturated polyester resin. The preparation of UPR/ LNR blends were conducted by varying the amount of LNR addition to the resin ranging from 0-7.5 % (wt). The composition of UPR/LNR blend with good mechanical properties had been selected as a matrix of the glass fiber reinforced composite. Glass fibre was also treated by (3-Amino propil)triethoxysilane as a coupling agent. From the result, the addition of 2.5 % LNR in UPR had showed the optimum mechanical and morphological properties where the elastomer particle's were well dispersed in the matrix with smaller size. The silane treatment on the glass fiber increased the tensile and impact strength values of the UPR/ LNR/ GF composite compared to untreated fiber reinforcement. (author)

  19. Comparison of proximal contacts of class II resin composite restorations in vitro.

    NARCIS (Netherlands)

    Loomans, B.A.C.; Opdam, N.J.M.; Roeters, F.J.M.; Bronkhorst, E.M.; Burgersdijk, R.C.W.

    2006-01-01

    This study investigated the tightness of the proximal contact when placing posterior resin composite restorations with circumferential and sectional matrix systems in an in vitro model using a special measuring device (Tooth Pressure Meter). A manikin model was used with an artificial first molar in

  20. Can repair increase the longevity of composite resins? Results of a 10-year clinical trial.

    Science.gov (United States)

    Fernández, E; Martín, J; Vildósola, P; Oliveira Junior, O B; Gordan, V; Mjor, I; Bersezio, C; Estay, J; de Andrade, M F; Moncada, G

    2015-02-01

    The aim of this double-blind clinical trial was to assess the longevity of repairs to localized clinical defects in composite resin restorations that were initially planned to be treated with a restoration replacement. Twenty-eight patients aged 18-80 years old with 50 composite resin restorations (CR) were recruited. The restorations with localized, marginal, anatomical deficiencies and/or secondary caries adjacent to CR that were "clinically judged" to be suitable for repair or replacement according to the USPHS criteria were randomly assigned to Repair (n=25) or Replacement (n=25) groups, and the quality of the restorations was scored according to the modified USPHS criteria. The restorations were blind and two examiners scored them at baseline (Cohen Kappa agreement score 0.74) and at ten years (Cohen Kappa agreement score 0.87) restorations. Wilcoxon tests were performed for comparisons within the same group (95% CI), and Friedman tests were utilized for multiple comparisons between the different years within each group. Over the decade, the two groups behaved similarly on the parameters of marginal adaptation (MA) (p>0.05), secondary caries (SC) (p>0.05), anatomy (A) (p0.05). Given that the MA, SC, A and C parameters behaved similarly in both groups, the repair of composite resins should be elected when clinically indicated, because it is a minimally invasive treatment that can consistently increase the longevity of restorations. The repair of defective composite resins as an alternative treatment to increase their longevity proved to be a safe and effective treatment in the long term. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. The role of the epoxy resin: Curing agent ratio in composite interfacial strength by single fibre microbond test

    DEFF Research Database (Denmark)

    Minty, Ross; Thomason, James L.; Petersen, Helga Nørgaard

    2015-01-01

    This paper focuses on an investigation into the role of the epoxy resin: curing agent ratio in composite interfacial shear strength of glass fibre composites. The procedure involved changing the percentage of curing agent (Triethylenetetramine [TETA]) used in the mixture with several different...... percentages used, ranging from 4% up to 30%, including the stoichiometric ratio. It was found by using the microbond test, that there may exist a relationship between the epoxy resin to curing agent ratio and the level of adhesion between the reinforcing fibre and the polymer matrix of the composite....

  2. Synthesis of improved phenolic and polyester resins

    Science.gov (United States)

    Delano, C. B.

    1980-01-01

    Thirty-seven cured phenolic resin compositions were prepared and tested for their ability to provide improved char residues and moisture resistance over state of the art epoxy resin composite matrices. Cyanate, epoxy novolac and vinyl ester resins were investigated. Char promoter additives were found to increase the anaerobic char yield at 800 C of epoxy novolacs and vinyl esters. Moisture resistant cyanate and vinyl ester compositions were investigated as composite matrices with Thornel 300 graphite fiber. A cyanate composite matrix provided state of the art composite mechanical properties before and after humidity exposure and an anaerobic char yield of 46 percent at 800 C. The outstanding moisture resistance of the matrix was not completely realized in the composite. Vinyl ester resins showed promise as candidates for improved composite matrix systems.

  3. The influence of FRCs reinforcement on marginal adaptation of CAD/CAM composite resin endocrowns after simulated fatigue loading.

    Science.gov (United States)

    Rocca, Giovanni Tommaso; Saratti, Carlo Massimo; Poncet, Antoine; Feilzer, Albert J; Krejci, Ivo

    2016-05-01

    To evaluate the marginal adaptation of endodontically treated molars restored with CAD/CAM composite resin endocrowns either with or without reinforcement by fibre reinforced composites (FRCs), used in different configurations. 32 human endodontically treated molars were cut 2 mm over the CEJ. Two interproximal boxes were created with the margins located 1 mm below the CEJ (distal box) and 1 mm over the CEJ (mesial box). All specimens were divided in four groups (n = 8). The pulp chamber was filled with: group 1 (control), hybrid resin composite (G-aenial Posterior, GC); group 2, as group 1 but covered by 3 meshes of E-glass fibres (EverStick NET, Stick Tech); group 3, FRC resin (EverX Posterior, GC); group 4, as group 3 but covered by 3 meshes of E-glass fibres. The crowns of all teeth were restored with CAD/CAM composite resin endocrowns (LAVA Ultimate, 3M). All specimens were thermo-mechanically loaded in a computer-controlled chewing machine (600,000 cycles, 1.6 Hz, 49 N and simultaneously 1500 thermo-cycles, 60 s, 5-55 °C). Marginal analysis before and after the loading was carried out on epoxy replicas by SEM at 200× magnification. For all the groups, the percentage values of perfect marginal adaptation after loading were always significantly lower than before loading (p marginal adaptation before and after loading was not significantly different between the experimental groups (p > 0.05). Within the limitations of this in vitro study, the use of FRCs to reinforce the pulp chamber of devitalized molars restored with CAD/CAM composite resin restorations did not significantly influenced their marginal quality.

  4. Clinical assessment of class II resin-based composites versus preformed metal crowns performed on primary molars in patients at high risk of caries.

    Science.gov (United States)

    Alyahya, A; Khanum, A; Qudeimat, M

    2018-02-01

    To compare class II resin composite with preformed metal crowns (PMC) in the treatment of proximal dentinal caries in high caries-risk patients. The charts (270) of paediatric patients with proximal caries of their primary molars were reviewed. Success or failure of a procedure was assessed using the dental notes. Survival analysis was used to calculate the mean survival time (MST) for both procedures. The influence of variables on the mean survival time was investigated. A total of 593 class II resin composites and 243 PMCs were placed in patients ranging between 4-13 years of age. The failure percentage of class II resin composites was 22.6% with the majority having been due to recurrent caries, while the failure percentage of PMCs was 15.2% with the majority due to loss of the crown. There was no significant difference between the MST of class II resin composites and PMCs, 41.3 and 45.6 months respectively (p value = 0.06). In class II resin composites, mesial restorations were associated with lower MST compared to distal restorations (p-value composites and PMCs were comparable when performed on high caries-risk patients.

  5. Impact of head and neck radiotherapy on the mechanical behavior of composite resins and adhesive systems: A systematic review.

    Science.gov (United States)

    Madrid Troconis, Cristhian Camilo; Santos-Silva, Alan Roger; Brandão, Thaís Bianca; Lopes, Marcio Ajudarte; de Goes, Mario Fernando

    2017-11-01

    To analyze the evidence regarding the impact of head and neck radiotherapy (HNRT) on the mechanical behavior of composite resins and adhesive systems. Searches were conducted on PubMed, Embase, Scopus and ISI Web of Science databases using "Radiotherapy", "Composite resins" and "Adhesive systems" as keywords. Selected studies were written in English and assessed the mechanical behavior of composite resins and/or adhesive systems when bonding procedure was conducted before and/or after a maximum radiation dose ≥50Gy, applied under in vitro or in vivo conditions. In total, 115 studies were found but only 16 were included, from which five evaluated the effect of in vitro HNRT on microhardness, wear resistance, diametral tensile and flexural strength of composite resins, showing no significant negative effect in most of reports. Regarding bond strength of adhesive systems, 11 studies were included from which five reported no meaningful negative effect when bonding procedure was conducted before simulated HNRT. Conversely, five studies showed that bond strength diminished when adhesive procedure was done after in vitro radiation therapy. Only two studies about dental adhesion were conducted after in vivo radiotherapy but the results were not conclusive. The mechanical behavior of composite resins and adhesive systems seems not to be affected when in vitro HNRT is applied after bonding procedure. However, bond strength of adhesive systems tends to decrease when simulated radiotherapy is used immediately before bonding procedure. Studies assessing dentin bond strength after in-vivo HNRT were limited and controversial. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Effect of ultraviolet light irradiation period on bond strengths between fiber-reinforced composite post and core build-up composite resin.

    Science.gov (United States)

    Asakawa, Yuya; Takahashi, Hidekazu; Iwasaki, Naohiko; Kobayashi, Masahiro

    2014-01-01

    The aim of the present study was to characterize the effects of the ultraviolet light (UV) irradiation period on the bond strength of fiber-reinforced composite (FRC) posts to core build-up resin. Three types of FRC posts were prepared using polymethyl methacrylate, urethane dimethacrylate, and epoxy resin. The surfaces of these posts were treated using UV irradiation at a distance of 15 mm for 0 to 600 s. The pull-out bond strength was measured and analyzed with the Dunnett's comparison test (α=0.05). The bond strengths of the post surfaces without irradiation were 6.9 to 7.4 MPa; those after irradiation were 4.2 to 26.1 MPa. The bond strengths significantly increased after 15 to 120-s irradiation. UV irradiation on the FRC posts improved the bond strengths between the FRC posts and core build-up resin regardless of the type of matrix resin.

  7. Recyclable epoxy resins: An example of green approach for advanced composite applications

    Science.gov (United States)

    Cicala, Gianluca; Rosa, Daniela La; Musarra, Marco; Saccullo, Giuseppe; Banatao, Rey; Pastine, Stefan

    2016-05-01

    Automotive composite applications are increasingly growing due to demand for lightweight structures to comply to the requirements for fuel reduction. HP-RTM is gaining relevance as one of the preferred production technologies for high volume applications. The BMW i3 life module being a notable example of HP-RTM application. The key aspects of HP-RTM are the short injection times (i.e. less than 1min) and the fast curing of the thermoset resins (i.e. less than 10min). The choice of using thermosets poses relevant issues for their limited recycling options. The standard recycling solution is the incineration but, this solution poses some concerns in terms of global environmental impact. Novel solutions are presented in this work based on the use of recyclable epoxy systems. In our work the results of experimentation carried out by our group with cleavable ammines by Connora Technologies and bioepoxy resins by Entropy Resins will be discussed. The multiple uses of recycled matrices obtained treating the recyclable epoxy resins are discussed in the framework of a "cradle" to "crave" approach. Finally, Life Cycle Assessment (LCA) is used to evaluate the environmental benefits of the proposed approach.

  8. Mechanical properties and fire retardancy of bidirectional reinforced composite based on biodegradable starch resin and basalt fibres

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available Environmental problems caused by extensive use of polymeric materials arise mainly due to lack of landfill space and depletion of finite natural resources of fossil raw materials, such as petroleum or natural gas. The substitution of synthetic petroleum-based resins with natural biodegradable resins appears to be one appropriate measure to remedy the above-mentioned situation. This study presents the development of a composite that uses environmentally degradable starch-based resin as matrix and basalt fibre plain fabric as reinforcement. Prepreg sheets were manufactured by means of a modified doctor blade system and a hot power press. The sheets were used to manufacture bidirectional-reinforced specimens with fibre volume contents ranging from 33 to 61%. Specimens were tested for tensile and flexural strength, and exhibited values of up to 373 and 122 MPa, respectively. Through application of silane coupling agents to the reinforcement fibres, the flexural composite properties were subsequently improved by as much as 38%. Finally, in order to enhance the fire retardancy and hence the applicability of the composite, fire retardants were applied to the resin, and their effectiveness was tested by means of flame rating (according to UL 94 and thermogravimetric analysis (TGA, respectively.

  9. Radiometric determinations of linear mass, resin levels and density of composite materials

    International Nuclear Information System (INIS)

    Boutaine, J.L.; Pintena, J.; Tanguy, J.C.

    1978-01-01

    A description is given of the principle, characteristics and performances of a gamma back-scattering gauge developed in cooperation between the CEA and SNPE. This instrument allows for on-line inspection of the linear mass and resin level of strips of composite materials whilst being produced. The industrial application involved boron, carbon and 'Kevlar' fibres. The performance of beta and gamma transmission gauges are also given for inspecting the density of panels and dense composite materials [fr

  10. Microwave absorption properties of barium titanate/epoxide resin composites

    International Nuclear Information System (INIS)

    Chen Xiaodong; Wang Guiqin; Duan Yuping; Liu Shunhua

    2007-01-01

    Nano-barium titanate (BT) was prepared by a sol-gel method. The prepared powders were characterized by x-ray powder diffraction and transmission electron microscopy. The complex relative dielectric permittivity (ε = ε' - jε-prime) and magnetic permeability (μ = μ' - jμ-prime) of the BT powders were measured in the frequency range 8 ∼ 18 GHz. The BT/epoxide resin (EP) composite with different volume contents was investigated. The effects of thickness on the BT/EP composite were studied. It was found that an optimum thickness and contents of the absorber can yield the maximum reflection loss which could be obtained over a broad frequency region in the X and Ku bands. Our results indicate that BT could be a promising microwave absorption material

  11. Adherence of Streptococcus Mutans to Microhybrid and Nanohybrid Resin Composites and Dental Amalgam: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Fariba Motevasselian

    2017-12-01

    Full Text Available Objectives: Streptococcus mutans (S. mutans is a cariogenic microorganism. The restorative materials which harbor a biofilm with high levels of S. mutans can accelerate the occurrence of dental caries. The purpose of this study was to evaluate the influence of different restorative materials on S. mutans colonization in a simple in-vitro biofilm formation model.Materials and Methods: Thirteen discs of each material (nanohybrid resin composite, microhybrid resin composite, and amalgam were prepared, polished, and sterilized in a gamma radiation chamber. The saliva-free specimens were exposed to the S. mutans bacterial suspension (0.5 McFarland and were incubated for 4 hours. Afterwards, the specimens were rinsed and sonicated in normal saline. 10µl of the obtained suspension was cultured in a sterile blood agar medium. After 24 hours, the number of colony forming units (CFU of S. mutans was counted. A sterility test control was considered for each group of materials. The data were analyzed by one-way ANOVA at 5% significance level.Results: The means and standard deviations of the logarithmic values of the colonies on the surfaces of amalgam, microhybrid, and nanohybrid resin composites were equal to 3.76±0.64, 3.91±0.52 and 3.34±0.74, respectively.Conclusions: There were no significant differences between the restorative materials in terms of S. mutans adhesion rate. The evaluated resin composites showed comparable numbers of CFUs, which could imply the importance of the polishing procedures.

  12. Comparative study to evaluate shear bond strength of RMGIC to composite resin using different adhesive systems

    Directory of Open Access Journals (Sweden)

    Manoj G Chandak

    2012-01-01

    Full Text Available Aim: The aim of the study is to compare and evaluate the role of new dental adhesives to bond composite to the resinmodified glass inomer cement (RMGIC. Materials and Methods: Thirty specimens were prepared on acrylic blocks, with wells prepared in it by drilling holes, to retain the RMGIC. The specimens were randomly divided into three groups of ten specimens each. In Group a thin layer of selfetch adhesive (3M ESPE was applied between the RMGIC and the composite resin FILTEK P60 (3M SPE. In Group II, total etch adhesive (Adeper Scotch bond 2, 3M ESPE was applied, and in Group III, there was no application of any adhesive between RMGIC and the composite resin. After curing all the specimens, the shear bond strength was measured using an Instron universal testing machine. Results: The results were drawn and tabulated using ANOVA-fishers and Dunnet D statistical tests.The maximum shear bond strength values were recorded in Group I specimens with self-etch adhesive showing a mean value of 2.74 when compared to the Group II adhesive (Total etch showing a mean shear strength of value 1.89, where no adhesive was used, showed a minimum mean shear bond strength of 1.42. There was a great and significant difference between Group I and Group II (P value 0.05 whereas, both Group I and Group II showed a vast and significant difference from Group III (P value = 0-001. Conclusion: Hence, this present study concludes that application of self-etch adhesive (3M ESPE, U.S.A in between RMGIC and composite resin increases the shear bond strength between RMGIC and the resin composites, as compared to the total-etch type adhesive (Adeper Scotch bond 2,3M ESPE, U.S.A as well as without application of the adhesive agent.

  13. [Effect of carbamide peroxide bleaching agents on micro-leakage of composite resin interface in vitro].

    Science.gov (United States)

    Wang, Xiao-ling; Xu, Juan; Zhao, Xin-yi; He, Hui-ming

    2011-01-01

    To evaluate the effect of carbamide peroxide (CP) bleaching agents at different concentrations and with different carriers on the micro-leakage of composite resin interface. Class V cavity (2 mm in diameter and 2 mm in depth) preparations were made at the enamelo-cemental junction on the buccal and lingual surfaces of 35 extracted human premolars. The cavities were filled with hybrid composite resin. The teeth were stored for 24 h in distilled water at 37 degrees celsius; before thermocyling for 500 times between 5 and 55 degrees celsius;. The teeth were then randomly assigned into 7 groups, and in groups 1-6, the bleaching gels containing 10% or 20% of CP were applied on the buccal and lingual surface of the teeth for two weeks (6-8 h/day, 37 degrees celsius;, 100% relative humidity) using Carbopol, PVP or Poloxamer as the thickening carriers, respectively. The seventh group served as the control without bleaching treatment. Nail polish was applied to the surface of the tooth, and all the teeth were immersed in ammoniacal silver nitrate solution followed by developing solution. The teeth were finally sectioned through the midline of the restoration and observed under stereomicroscope. SEM micrographs were also made to observe the interface. With the same bleaching agent, the micro-leakage in the gingival wall was slightly greater than in the occlusive wall, but the difference was not significant. Only 20% CP with Poloxamer as the thickening agent significantly increased the leakage of dentine-resin composite interface, and 10% and 20% CP with Carbopol or PVP as the thickening agents and 10% CP with Poloxamer produced minimal effects on filling the micro-leakage. Thickening carriers and the concentration of CP (20% or below) have no significant effect on micro-leakage of composite resin.

  14. The effect of different beverages on surface hardness of nanohybrid resin composite and giomer.

    Science.gov (United States)

    Tanthanuch, Saijai; Kukiattrakoon, Boonlert; Siriporananon, Chantima; Ornprasert, Nawanda; Mettasitthikorn, Wathu; Likhitpreeda, Salinla; Waewsanga, Sulawan

    2014-05-01

    To investigate the effects of five beverages (apple cider, orange juice, Coca-Cola, coffee, and beer) on microhardness and surface characteristic changes of nanohybrid resin composite and giomer. Ninety-three specimens of each resin composite and giomer were prepared. Before immersion, baseline data of Vicker's microhardness was recorded and surface characteristics were examined using scanning electron microscopy (SEM). Five groups of discs (n = 18) were alternately immersed in 25 mL of each beverage for 5 s and in 25 mL of artificial saliva for 5 s for 10 cycles. Specimens were then stored in artificial saliva for 24 h. This process was repeated for 28 days. After immersion, specimens were evaluated and data were analyzed by two-way repeated analysis of variance (ANOVA), Tukey's honestly significant difference (HSD), and a t-test (α = 0.05). Microhardness of all groups significantly decreased after being immersed in the tested beverages (P composition of the restorative materials and beverages.

  15. Replacement of Anterior Composite Resin Restorations Using Conservative Ceramics for Occlusal and Periodontal Rehabilitation: An 18-Month Clinical Follow-Up

    Directory of Open Access Journals (Sweden)

    Leonardo Fernandes da Cunha

    2016-01-01

    Full Text Available This case report describes a patient with discolored and fractured composite resin restorations on the anterior teeth in whom substitution was indicated. After wax-up and mock-up, the composite was removed and replaced with minimally invasive ceramic laminates. An established and predictable protocol was performed using resin cement. Minimally invasive ceramic restorations are increasingly being used to replace composite restorations. This treatment improves the occlusal and periodontal aspects during the planning and restorative phases, such as anterior guides, and laterality can be restored easily with ceramic laminates. In addition, the surface smoothness and contour of ceramic restorations do not affect the health of the surrounding periodontal tissues. Here we present the outcome after 18 months of clinical follow-up in a patient in whom composite resin restorations in the anterior teeth were replaced with minimally invasive ceramic laminates.

  16. Influence of bleaching agents on the microhardness of nanoparticle resin composite

    Directory of Open Access Journals (Sweden)

    Vanderlei Salvador Bagnato

    2009-01-01

    Full Text Available Objective: To assess the effect of bleaching agents on the microhardness of nanoparticle resin composite. Methods: Twenty-eight cylindrical test specimens (8x1mm of FiltekTM Supreme XT resin (3M/ESPE were prepared and divided into 5 groups. The initial Vickers microhardness was measured (load of 50 grams force for 30 seconds on the top surface of the test specimens. The groupswere treated and divided as follows: G1 – artificial saliva (21 days - control; G2 - 7% hydrogen peroxide gel applied for 4h/day, for 14 days; G3 - 10% carbamide peroxide for 4h/day, for 14 days: G4 – 35% hydrogen peroxide gel applied in three sessions of 30 minutes each, with an interval of one week (21 days between the sessions; G5 - 35% carbamide peroxide, three sessions of 30 minutes each, with an interval of one week (21 days between the sessions. The top surfaces of the test specimens received treatment and were submitted to the Vickers microhardness test. Results: The results obtained were submitted to the Analysis of Variance at a fixed criterion, at a level of significance of p=0.05. No significant differences were observed among the treatments tested (p=0.42 when compared with G1. Significant differences (Tukey test were found when the initial microhardness values were compared with the values after experimental treatments (p<0.01. Conclusion: The application of bleaching agents did not alter the microhardness of resin composites. Therefore, there is no need to change restorations after bleaching.

  17. Evaluation of the polymerization shrinkage of experimental flowable composite resins through optical coherence tomography

    Science.gov (United States)

    Carneiro, Vanda S. M.; Mota, Cláudia C. B. O.; Souza, Alex F.; Cajazeira, Marlus R. R.; Gerbi, Marleny E. M. M.; Gomes, Anderson S. L.

    2018-02-01

    This study evaluated the polymerization shrinkage of two experimental flowable composite resins (CR) with different proportions of Urethane dimethacrylate (UDMA)/triethylene glycol dimethacrylate (TEGDMA) monomers in the organic matrix (50:50 and 60:40, respectively). A commercially available flowable CR, Tetric N-Flow (Ivoclair Vivadent, Liechtenstein, Germany), was employed as the control group. The resins were inserted in a cylindrical teflon mold (7 mm diameter, 0.6 mm height) and scanned with OCT before photoactivation, immediately after and 15 minutes after light-curing (Radii-Cal, SDI, Australia, 1,200 mW/cm2 ) exposure. A Callisto SD-OCT system (Thorlabs Inc, USA), operating at 930 nm central wavelength was employed for imaging acquisition. Cross-sectional OCT images were captured with 8 mm transverse scanning (2000x512 matrix), and processed by the ImageJ software, for comparison between the scanning times and between groups. Pearson correlation showed significant shrinkage for all groups in each time analyzed. Kruskal-Wallis test showed greater polymerization shrinkage for the 50:50 UDMA/TEGDMA group (p=0.001), followed by the control group (p=0.018). TEGDMA concentration was proportionally related to the polymerization shrinkage of the flowable composite resins.

  18. New-generation curing units and short irradiation time: the degree of conversion of microhybrid composite resin.

    Science.gov (United States)

    Scotti, Nicolla; Venturello, Alberto; Migliaretti, Giuseppe; Pera, Francesco; Pasqualini, Damiano; Geobaldo, Francesco; Berutti, Elio

    2011-09-01

    This in vitro study investigated the depth of cure of a microhybrid composite resin when cured with reduced times of exposure to three commercially available curing lights. Different sample thicknesses (1, 2, and 3 mm) were light cured in high intensity polymerization mode (2,400 mW/cm² for 5, 10, 15, and 20 seconds; 1,100 mW/cm² for 10, 20, 30, and 40 seconds; and 1,100 mW/cm² for 10, 20, 30, and 40 seconds, respectively). The degree of conversion (%) at the bottom of each sample was measured by Attenuated Total Reflection Fourier Transform Infrared (ATR F-TIR) analysis after each polymerization step. Data were analyzed by ANOVA for repeated measures, showing the degree of conversion was not influenced by the curing light employed (P = .622) but was significantly influenced by the thickness of composite resin (P conversion vs the shorter irradiation time permitted (T1) were not significant among different lamps but were significant among different thicknesses. The depth of cure of microhybrid composite resin appears not to be influenced by the curing light employed. Increased irradiation time significantly increases the degree of conversion. Thickness strongly influences depth of cure.

  19. Effects of LDEF flight exposure on selected polymer matrix resin composite materials

    Science.gov (United States)

    Slemp, Wayne S.; Young, Philip R.; Witte, William G., Jr.; Shen, James Y.

    1992-01-01

    The characterization of selected graphite fiber reinforced epoxy (934 and 5208) and polysulfone (P1700) matrix resin composites materials which received over five years and nine months of exposure to the low earth orbit (LEO) environment in experiment AO134 on the Long Duration Exposure Facility is reported. The changes in mechanical properties of ultimate tensile strength and tensile modulus for exposed flight specimens are compared to the three sets of control specimens. Marked changes in surface appearance are discussed, and resin loss is reported. The chemical characterization including infrared, thermal, and selected solution property measurements showed that the molecular structure of the polymetric matrix had not changed significantly in response to this exposure.

  20. Temperature dependence of the electromagnetic properties and microwave absorption of carbonyl iron particles/silicone resin composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yingying; Zhou, Wancheng; Qing, Yuchang; Luo, Fa; Zhu, Dongmei

    2015-01-15

    Microwave absorbing composites with thin thickness and wideband absorption were successfully prepared by a spraying method using carbonyl iron particles (CIPs) as absorbers and silicone resin as the matrix. The value of reflection loss (RL) below −5 dB can be obtained in the frequency range of 5.76–18 GHz for the composite with 0.8 mm thickness. The temperature dependence of electromagnetic properties and RL of the composites were investigated. The RL of the composite showed a slight variation when the temperature reached up to 200 °C while decreased at 300 °C. The room temperature RL of the composite did not display significant difference before and after the heat treatment at 300 °C for 10 h; the mechanism was also discussed. - Highlights: • Carbonyl iron particles/silicone resin composites are prepared by a spraying method. • Reflection loss values exceed −5 dB at 5.76–18 GHz for an absorber of 0.8 mm thickness. • The variation of reflection loss was studied from room temperature to 300 °C.

  1. Synthesis of some Ferromagnetic Composite Resins and their Metal Removal Characteristics in Aqueous Solutions

    International Nuclear Information System (INIS)

    Sheha, R.R.; EI-Zahhar, A.A.

    2008-01-01

    In this study, a procedure for synthesis of new organic-inorganic magnetic composite resins was established. The procedure was based upon immobilization of magnetite as a ferromagnetic material within the polymeric (poly(acrylic acid acrylonitrile) and IRC-120) ion exchange resins. The produced magnetic resins were evaluated as sorbents for CI(VI). The factors influencing the sorption of Cr(Vl), e.g., ph, equilibrium time, initial concentration and temperature were studied. The sorption process was very fast initially and maximum sorption was achieved within 3 h at ph 5.1. Thc kinetics of the system have been evaluated with pseudo first order model, second order model, Elovich equation, intra-particle diffusion model and liquid film diffusion model. Chromium interaction with composite particles followed second-order kinetics with a correlation coefficient extremely high and closer to unity and rate constant (k s ) has the values 1.68 x 10 -4 and 1.9 x 10 -4 g/mg min for IRC-120-P AN-magnetite and P(AA-AN)-magnetite composites, respectively. The values of equilibrium sorption capacity (q e ) are consistent with the modeled data and attain the range 893 - 951 mg/g. Kinetically, both pore diffusion and film diffusion are participating in ruling the diffusion of CI(VI) ions. The sorption data gave good fits with Temkin and Flory-Huggins isotherm models. The isotherm parameters related to the heat of sorption are in the range 8-16 kJ mol -1 which is the range of bonding energy for ion exchange interactions and so suggest an ion exchange mechanism for removal of CI(VI) by the composite sorbents. The adsorption process was exothermic with δH in the range of -73 to -97 kJ/mol. The negative values of Gibbs free energy confirm the feasibility and the spontaneous nature of removal of CI(VI) with these novel composites

  2. Fracture toughness of dentin/resin-composite adhesive interfaces.

    Science.gov (United States)

    Tam, L E; Pilliar, R M

    1993-05-01

    The reliability and validity of tensile and shear bond strength determinations of dentin-bonded interfaces have been questioned. The fracture toughness value (KIC) reflects the ability of a material to resist crack initiation and unstable propagation. When applied to an adhesive interface, it should account for both interfacial bond strength and inherent defects at or near the interface, and should therefore be more appropriate for characterization of interface fracture resistance. This study introduced a fracture toughness test for the assessment of dentin/resin-composite bonded interfaces. The miniature short-rod specimen geometry was used for fracture toughness testing. Each specimen contained a tooth slice, sectioned from a bovine incisor, to form the bonded interface. The fracture toughness of an enamel-bonded interface was assessed in addition to the dentin-bonded interfaces. Tensile bond strength specimens were also prepared from the dentin surfaces of the cut bovine incisors. A minimum of ten specimens was fabricated for each group of materials tested. After the specimens were aged for 24 h in distilled water at 37 degrees C, the specimens were loaded to failure in an Instron universal testing machine. There were significant differences (p adhesives tested. Generally, both the fracture toughness and tensile bond strength measurements were highest for AllBond 2, intermediate for 3M MultiPurpose, and lowest for Scotchbond 2. Scanning electron microscopy of the fractured specimen halves confirmed that crack propagation occurred along the bond interface during the fracture toughness test. It was therefore concluded that the mini-short-rod fracture toughness test provided a valid method for characterization of the fracture resistance of the dentin-resin composite interface.

  3. A One-Component, Fast-Cure, and Economical Epoxy Resin System Suitable for Liquid Molding of Automotive Composite Parts

    Directory of Open Access Journals (Sweden)

    Yiru Wang

    2018-04-01

    Full Text Available Imidazole cured epoxy resin systems were evaluated for one-component, fast-curing resins for liquid molding of automotive composite parts according to industry requirements. It was demonstrated that an epoxy resin-1-(cyanoethyl-2-ethyl-4-methylimidazol(EP-1C2E4MIM system would cure in a few minutes at 120 °C, while exhibiting acceptable pot life, viscosity profiles, and low water absorption. Moreover, this system yielded high Tg parts with mechanical properties similar to the amine-epoxy systems, which are the mainstream two-component epoxy resin systems for automobiles.

  4. Marginal microleakage of resin-modified glass-ionomer and composite resin restorations: Effect of using etch-and-rinse and self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2012-01-01

    Full Text Available Objectives: Previous studies have shown that dental adhesives increase the bond strength of resin-modified glass-ionomer (RMGI restorative materials to dentin. This in vitro study has evaluated the effect of etch-and-rinse and self-etch bonding systems v/s cavity conditioner, and in comparison to similar composite resin restorations on maintaining the marginal sealing of RMGI restorations. Materials and Methods: 98 rectangular cavities (2.5×3×1.5 mm were prepared on buccal and palatal aspects of 49 human maxillary premolars, randomly divided into 7 groups (N=14. The cavities in groups 1, 2 and 3 were restored using a composite resin (APX. The cavities in groups 4, 5, 6 and 7 were restored using a resin-modified glass-ionomer (Fuji II LC. Before restoring, adhesive systems (Optibond FL = OFL, three-step etch-and-rinse; One Step Plus = OSP, two-step etch-and-rinse; Clearfil Protect Bond = CPB, two-step self-etch were used as bonding agents in groups 1-6 as follow: OFL in groups 1 and 4, OSP in groups 2 and 5, and CPB in groups 3 and 6, respectively. The specimens in group 7 were restored with GC cavity conditioner and Fuji II LC. All the specimens were thermo-cycled for 1000 cycles. Microleakage scores were determined using dye penetration method. Statistical analyzes were carried out with Kruskal-Wallis and Mann-Whitney U tests (α=0.05. Results: There were significant differences in microleakage scores at both enamel and dentinal margins between the study groups (P<0.05. The lowest microleakage scores at enamel and dentin margins of RMGI restorations were observed in group 6. Conclusion: Use of two-step self-etch adhesive, prior to restoring cervical cavities with RMGIC, seems to be more efficacious than the conventional cavity conditioner in decreasing marginal microleakage.

  5. Treatment of low level radioactive liquid wastes using composite ion-exchange resins based on polyurethane foam

    International Nuclear Information System (INIS)

    Rao, S.V.S.; Lekshmi, R.; Mani, A.G.S.; Sinha, P.K.

    2010-01-01

    Composite ion-exchange resins were prepared by coating copper-ferrocyanide (CFC) and hydrous manganese oxide (HMO) powders on polyurethane (PU) foam. Polyvinyl acetate/Acetone was used as a binder. The foam was loaded with about five times its weight with CFC and HMO powders. The distribution coefficients of CFC-PU foam and HMO-PU foam for cesium and strontium respectively were estimated. Under similar conditions the HMO-PU foam showed higher capacity as well as better kinetics for removal of strontium than CFC-PU foam for Cs. The pilot plant scale studies were conducted using a mixed composite ion-exchange resin bed. About 1000 bed volumes could be passed before attaining a DF of 10 from an initial value of 60-80. The spent resin was digested in alkaline KMnO 4 and the digested liquid was fixed in cement matrix. The matrices were characterized with respect to compressive strength and leach resistance. (author)

  6. The effect of different polishing systems on surface roughness and gloss of various resin composites.

    Science.gov (United States)

    Da Costa, Juliana; Ferracane, Jack; Paravina, Rade D; Mazur, Rui Fernando; Roeder, Leslie

    2007-01-01

    The purpose of this in vitro study was to evaluate the surface finish and gloss of five direct resin composites polished with six polishing systems. One hundred and fifty disk-shaped composite specimens (D=10.0 mm, 2-mm-thick, N=30 per material) were made. One side of each specimen was finished with a 16-fluted carbide finishing bur and then polished. Five specimens of each resin composite were randomly assigned to one of the six polishing systems. The surface roughness and gloss were measured with a surface profilometer and a glossmeter. The results were analyzed by two-way analysis of variance and Tukey's t-test (pgloss values between the composites and the polishing systems (p gloss value was recorded for Supreme + Pogo; the lowest was recorded for Z100 + Jiffy. Pogo showed the highest gloss values for all composites. The nanofill (Supreme) and minifill (Esthet-X) composites presented a surface roughness comparable to a microfill (Durafill), independent of the polishing system used, and a gloss comparable to a microfill, when polished with a one-step system (Pogo). As compared with the multiple-step systems, the smoothest surfaces and the highest gloss values were achieved using the one-step system (Pogo) for all the evaluated composites.

  7. Color stability of bulk-fill and incremental-fill resin-based composites polished with aluminum-oxide impregnated disks

    Directory of Open Access Journals (Sweden)

    Uzay Koc-Vural

    2017-05-01

    Full Text Available Objectives This study aimed to evaluate the color stability of bulk-fill and nanohybrid resin-based composites polished with 3 different, multistep, aluminum-oxide impregnated finishing and polishing disks. Materials and Methods Disk-shaped specimens (8 mm in diameter and 4 mm in thickness were light-cured between two glass slabs using one nanohybid bulk-fill (Tetric EvoCeram, Ivoclar Vivadent, one micro-hybrid bulk-fill (Quixfil, Dentsply, and two nanohybrid incremental-fill (Filtek Ultimate, 3M ESPE; Herculite XRV Ultra, Kerr resin-based composites, and aged by thermocycling (between 5 - 55℃, 3,000 cycles. Then, they were divided into subgroups according to the polishing procedure as SwissFlex (Coltène/Whaledent, Optidisc (Kerr, and Praxis TDV (TDV Dental (n = 12 per subgroup. One surface of each specimen was left unpolished. All specimens were immersed in coffee solution at 37℃. The color differences (ΔE were measured after 1 and 7 days of storage using a colorimeter based on CIE Lab system. The data were analyzed by univariate ANOVA, Mann-Whitney U test, and Friedmann tests (α = 0.05. Results Univariate ANOVA detected significant interactions between polishing procedure and composite resin and polishing procedure and storage time (p 0.05. Polishing reduced the discoloration resistance of Tetric EvoCeram/SwissFlex, Tetric EvoCeram/Praxis TDV, Quixfil-SwissFlex, and all Herculite XRV Ultra groups after 7 days storage (p < 0.05. Conclusions Discoloration resistance of bulk-fill resin-based composites can be significantly affected by the polishing procedures.

  8. Effect of Energy Drinks on Discoloration of Silorane and Dimethacrylate-Based Composite Resins.

    Science.gov (United States)

    Ahmadizenouz, Ghazaleh; Esmaeili, Behnaz; Ahangari, Zohreh; Khafri, Soraya; Rahmani, Aghil

    2016-08-01

    This study aimed to assess the effects of two energy drinks on color change (ΔE) of two methacrylate-based and a silorane-based composite resin after one week and one month. Thirty cubic samples were fabricated from Filtek P90, Filtek Z250 and Filtek Z350XT composite resins. All the specimens were stored in distilled water at 37°C for 24 hours. Baseline color values (L*a*b*) of each specimen were measured using a spectrophotometer according to the CIEL*a*b* color system. Ten randomly selected specimens from each composite were then immersed in the two energy drinks (Hype, Red Bull) and artificial saliva (control) for one week and one month. Color was re-assessed after each storage period and ΔE values were calculated. The data were analyzed using the Kruskal Wallis and Mann-Whitney U tests. Filtek Z250 composite showed the highest ΔE irrespective of the solutions at both time points. After seven days and one month, the lowest ΔE values were observed in Filtek Z350XT and Filtek P90 composites immersed in artificial saliva, respectively. The ΔE values of Filtek Z250 and Z350XT composites induced by Red Bull and Hype energy drinks were not significantly different. Discoloration of Filtek P90 was higher in Red Bull energy drink at both time points. Prolonged immersion time in all three solutions increased ΔE values of all composites. However, the ΔE values were within the clinically acceptable range (<3.3) at both time points.

  9. Simulation of the Vacuum Assisted Resin Transfer Molding (VARTM) process and the development of light-weight composite bridging

    Science.gov (United States)

    Robinson, Marc J.

    A continued desire for increased mobility in the aftermath of natural disasters, or on the battlefield, has lead to the need for improved light-weight bridging solutions. This research investigates the development of a carbon/epoxy composite bridging system to meet the needs for light-weight bridging. The research focuses on two main topics. The first topic is that of processing composite structures and the second is the design and testing of these structures. In recent years the Vacuum Assisted Resin Transfer Molding (VARTM) process has become recognized as a low-cost manufacturing alternative for large Fiber Reinforced Polymer (FRP) composite structures for civil, military, and aerospace applications. The success of the VARTM process (complete wet-out) is very sensitive to the resin injection strategy used and the proper placement of flow distribution materials and inlet and vacuum ports. Predicting the flow front pattern, the time required for infusing a part with resin, and the time required to bleed excess resin at the end of filling, is critical to ensure that the part will become completely impregnated and desired fiber volume fractions achieved prior to the resin gelling (initiation of cure). In order to eliminate costly trial and error experiments to determine the optimal infusion strategy, this research presents a simulation model which considers in-plane flow as well as flow through the thickness of the preform. In addition to resin filling, the current model is able to simulate the bleeding of resin at the end of filling to predict the required bleeding time to reach desired fiber volume fractions for the final part. In addition to processing, the second portion of the dissertation investigates the design and testing of composite bridge deck sections which also serve as short-span bridging for gaps up to 4 m in length. The research focuses on the design of a light-weight core material for bridge decking as well as proof loading of short-span bridge

  10. Pengaruh Minuman Kopi terhadap Perubahan Warna pada Resin Komposit

    Directory of Open Access Journals (Sweden)

    Aprilia Aprilia

    2015-10-01

    Full Text Available Objective: The aim of this research was to investigate the influence of coffee beverage on hybrid composite resin discoloration. Material and method: This study used hybrid composite resin with A3 color, and was done by soaking composite resin plates in coffee solution for 1, 3, 5, and 7 days, corresponding to equivalent coffee usage for 6 months, 1, 1.5, and 2 years. The same measurements of reflectance were done before and after soaking into coffee solution. In the measurement, a beam from He-Ne laser is reflected by the sample to a photovoltaic cell type BOY-47, which provides a voltage signal accordig to the intensity of reflected light. Results: There was a significant difference between composite resin plates before and after soaking into coffee dilution for 1, 3, 5, and 7 days. Conclusion: Composite resin is discolored after soaking into a coffee solution, suggesting that coffee usage will have a discoloring effect on dental composite resin.

  11. Fracture Resistance of Premolars Restored by Various Types and Placement Techniques of Resin Composites

    Directory of Open Access Journals (Sweden)

    Horieh Moosavi

    2012-01-01

    Full Text Available To verify the fracture resistance of premolars with mesioocclusodistal preparations restored by different resin composites and placement techniques. Sixty premolars were randomly divided into two groups based on type of composite resin: Filtek P60 or Nulite F, and then each group was separated into three subgroups: bulk, centripetal, and fiber insert according to the type of placement method (n=10. Single-bond adhesive system was used as composite bonding according to the manufacturer's instructions. Specimens were restored in Groups 1, 2, and 3 with Filtek P60 and in Groups 4, 5, and 6 with Nulite F. After being stored 24 hours at 37∘C, a 4 mm diameter steel sphere in a universal testing machine was applied on tooth buccal and lingual cusps at a cross-head speed of 5 mm/min until fracture occurred. Groups 3 and 6 showed higher fracture resistance than Groups 1, 2, 4, and 5. Among the placement techniques, the fiber insert method had a significant effect, but the type of composite was ineffective. The insertion technique in contrast to the type of material had a significant influence on the fracture resistance of premolar teeth.

  12. Comparison of different finishing/polishing systems on surface roughness and gloss of resin composites.

    Science.gov (United States)

    Antonson, Sibel A; Yazici, A Rüya; Kilinc, Evren; Antonson, Donald E; Hardigan, Patrick C

    2011-07-01

    The aim of this study was to compare four finishing/polishing systems (F/P) on surface roughness and gloss of different resin composites. A total of 40 disc samples (15 mm × 3 mm) were prepared from a nanofill - Filtek Supreme Plus (FS) and a micro-hybrid resin composite - Esthet-X (EX). Following 24h storage in 37°C water, the top surfaces of each sample were roughened using 120-grit sandpaper. Baseline measurements of surface roughness (Ra, μm) and gloss were recorded. Each composite group was divided into four F/P disk groups: Astropol[AP], Enhance/PoGo[EP], Sof-Lex[SL], and an experimental disk system, EXL-695[EXL] (n=5). The same operator finished/polished all samples. One sample from each group was evaluated under SEM. Another blinded-operator conducted postoperative measurements. Results were analysed by two-way ANOVA, two interactive MANOVA and Tukey's t-test (p0.01). In gloss, FS composite with the EXL-695 system provided a significantly higher gloss (pgloss (pgloss. SEM evaluations revealed that the EX surface contained more air pockets but F/P systems were compatible. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Nanostructure of tetrafunctional epoxy resins and composites: Correlation to moisture absorption properties

    Science.gov (United States)

    Bolan, Brett Andrew

    The effect that changes in network topology, while maintaining a constant network polarity (i.e. thermodynamic driving force was kept constant), had upon the moisture absorption properties of an aerospace grade tetrafunctional epoxy (TGMDA) cured with multifunctional amines were investigated. Utilizing Positron Annihilation Lifetime Spectroscopy (PALS) to characterize the nanoscale structure of these epoxies, it was found that as the "static" hole volume (a measurement of packing defects at 0K) increased so did the equilibrium uptake. PALS studies of one of these resins cured to varying extents, found that this static amount increased with degree of cure indicating that the network becomes more open as a direct consequence of crosslinking. Polar groups, which are the attractive force for diffusion, are in the vicinity of these crosslinks, therefore it is believed that the increase in static hole volume results in exposing more polar groups for absorption. The diffusion coefficient, which is representative of the kinetic aspect of diffusion, was also investigated. It was discovered that the amount of nanohole volume in the polymer; whether the total, the static, or dynamic (i.e. thermally activated) does not correlate to the diffusion coefficient in anyway. Furthermore, at an isotherm the diffusion coefficients for all these materials were relatively constant. From this it is hypothesized that it is the similar sub-Tsb{g} motions of these resins which is the rate limiting step in diffusion. This was bolstered by the fact that the activation energy for diffusion and for the sub-Tsb{g} motions for these epoxies are of the same order of magnitude. The nanostructure of fiber reinforced epoxy composites (i.e. a boron/epoxy and a graphite/epoxy) were probed with the bulk PALS technique as well. It was observed that for the graphite/epoxy composite and its flash (i.e. no fibers present) cured under identical conditions, that the nanoholes in the composite were larger than

  14. Autoclave processing for composite material fabrication. 1: An analysis of resin flows and fiber compactions for thin laminate

    Science.gov (United States)

    Hou, T. H.

    1985-01-01

    High quality long fiber reinforced composites, such as those used in aerospace and industrial applications, are commonly processed in autoclaves. An adequate resin flow model for the entire system (laminate/bleeder/breather), which provides a description of the time-dependent laminate consolidation process, is useful in predicting the loss of resin, heat transfer characteristics, fiber volume fraction and part dimension, etc., under a specified set of processing conditions. This could be accomplished by properly analyzing the flow patterns and pressure profiles inside the laminate during processing. A newly formulated resin flow model for composite prepreg lamination process is reported. This model considers viscous resin flows in both directions perpendicular and parallel to the composite plane. In the horizontal direction, a squeezing flow between two nonporous parallel plates is analyzed, while in the vertical direction, a poiseuille type pressure flow through porous media is assumed. Proper force and mass balances have been made and solved for the whole system. The effects of fiber-fiber interactions during lamination are included as well. The unique features of this analysis are: (1) the pressure gradient inside the laminate is assumed to be generated from squeezing action between two adjacent approaching fiber layers, and (2) the behavior of fiber bundles is simulated by a Finitely Extendable Nonlinear Elastic (FENE) spring.

  15. Mechanical properties and environmental effects of epoxy resins in the neat state and in composites

    International Nuclear Information System (INIS)

    Yang, C.M.P.

    1984-01-01

    The dynamic mechanical properties of graphite fiber reinforced, epoxy matrix composite laminates subjected to loading perpendicular to the plane of lamination and of neat epoxy resin are reported. The centrosymmetric deformation (CSD) test geometry provides an accurate and convenient test mode for the study of the viscoelastic behavior of very stiff graphite-epoxy laminates. It is found that the in-phase and out-of-phase stiffness superpose to form master curves covering a frequency range of 12 decades. By a suitable scaling procedure of the master curves, it is found that the in-phase stiffness has the same shape and the out-of-phase has the same dispersion for all laminates irrespective of the stacking sequence. The dispersion characteristics of in-situ and neat resin epoxy were nearly identical, but with the neat resin having a lower glass-transition temperature. The graphite/epoxy composites and neat resin epoxy have been shown to be sensitive to hygrothermal environment. For postcured specimens the plasticization and inhomogeneous swelling effects due to the moisture absorbed are found to be reversible, in the sense that the initially dry properties of the laminate are recovered after redrying the wet specimen. On the other hand, for as cured specimens, the plasticization and inhomogeneous swelling effects are found to be irreversible under the same hygrothermal environment

  16. Evaluation of temperature rise with different curing methods and units in two composite resins

    Directory of Open Access Journals (Sweden)

    Tabatabaei M

    2006-01-01

    Full Text Available Background and Aim: The majority of commercial curing units in dentistry are of halogen lamp type. The new polymerizing units such as blue LED are introduced in recent years. One of the important side effects of light curing is the temperature rise in composite resin polymerization which can affect the vitality of tooth pulp. The purpose of this study was to evaluate the temperature rise in two different composite resins during polymerization with halogen lamps and blue LED. Materials and Methods: This experimental study investigated the temperature rise in two different composites (Hybrid, Tetric Ceram/Nanofilled, Filteke Supreme of A2 shade polymerized with two halogen lamps (Coltolux 50, 350 mW/cm2 and Optilux 501 in standard, 820 mW/cm2 and Ramp, 100-1030 mW/cm2 operating modes and one blue LED with the intensity of 620 mW/cm2. Five samples for each group were prepared and temperature rise was monitored using a k-type thermocouple. Data were analyzed by one-way ANOVA, two-way ANOVA and Tukey HSD tests with P<0.05 as the limit of significance. Results: Light curing units and composite resins had statistically significant influence on the temperature rise (p<0.05. Significantly, lower temperature rise occurred in case of illumination with Coltolux 50.There was no significant difference between Optilux 501 in standard curing mode and LED. Tetric Ceram showed higher temperature rise. Conclusion: According to the results of this study the high power halogen lamp and LED could produce significant heat which may be harmful to the dental pulp.

  17. [Effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker].

    Science.gov (United States)

    Zhu, Ming-yi; Zhang, Xiu-yin

    2015-06-01

    To evaluate the effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker (ABW). ABW was surface-treated with 0%, 1%, 2%, 3% and 4% silan coupling agent (γ-MPS), and mixed with resin matrix to synthesize 5 groups of composite resins. After heat-cured at 120 degrees centigrade for 1 h, specimens were tested in three-point flexure to measure strength according to ISO-4049. One specimen was selected randomly from each group and observed under scanning electron microscope (SEM). The data was analyzed with SAS 9.2 software package. The flexural strength (117.93±11.9 Mpa) of the group treated with 2% silane coupling agent was the highest, and significantly different from that of the other 4 groups (α=0.01). The amount of silane coupling agent has impact on the flexural strength of dental composite resins reinforced with whiskers; The flexual strength will be reduced whenever the amount is higher or lower than the threshold. Supported by Research Fund of Science and Technology Committee of Shanghai Municipality (08DZ2271100).

  18. Voltage-Induced Nonlinear Conduction Properties of Epoxy Resin/Micron-Silver Particles Composites

    Science.gov (United States)

    Qu, Zhaoming; Lu, Pin; Yuan, Yang; Wang, Qingguo

    2018-01-01

    The nonlinear conduction properties of epoxy resin (ER)/micron-silver particles (MP) composites were investigated. Under sufficient high intensity applied constant voltage, the obvious nonlinear conduction properties of the samples with volume fraction 25% were found. With increments in the voltage, the conductive switching effect was observed. The nonlinear conduction mechanism of the ER/MP composites under high applied voltages could be attributed to the electrical current conducted via discrete paths of conductive particles induced by the electric field. The test results show that the ER/MP composites with nonlinear conduction properties are of great potential application in electromagnetic protection of electron devices and systems.

  19. Aesthetic Closure of Maxillary and Mandibular Anterior Spaces Using Direct Composite Resin Build-Ups: A Case Report

    Directory of Open Access Journals (Sweden)

    Schick Simona-Georgiana

    2016-07-01

    Full Text Available The presence of multiple spaces in the anterior aesthetic zone can produce discomfort for patients and its treatment can be difficult for dental professionals. A variety of treatment options are available and these include orthodontic movement, prosthetic indirect restorations or direct composite resin build-ups. Among these, the closure of interdental spaces using composite build-ups combined with orthodontic treatment is considered to be most conservative. This type of treatment has several advantages like the maximum preservation of tooth substance (no tooth preparation, no need for anesthesia, no multiple time-consuming visits, no provisional restorations and also comparably low costs. Clinical Consideration: This case report describes the clinical restorative procedure of direct composite resin build-ups for the closure of multiple anterior spaces.

  20. Fine-Tuning of Polymeric Resins and their Interfaces with Amorphous Calcium Phosphate. A Strategy for Designing Effective Remineralizing Dental Composites

    Directory of Open Access Journals (Sweden)

    Drago Skrtic

    2010-09-01

    Full Text Available For over a decade our group has been designing, preparing and evaluating bioactive, remineralizing composites based on amorphous calcium phosphate (ACP fillers embedded in polymerized methacrylate resin matrices. In these studies a major focus has been on exploring structure-property relationships of the matrix phase of these composites on their anti-cariogenic potential. The main challenges were to gain a better understanding of polymer matrix/filler interfacial properties through controlling the surface properties of the fillers or through fine-tuning of the resin matrix. In this work, we describe the effect of chemical structure and composition of the resin matrices on some of the critical physicochemical properties of the copolymers and their ACP composites. Such structure-property studies are essential in formulating clinically effective products, and this knowledge base is likely to have strong impact on the future design of therapeutic materials, appropriate for mineral restoration in defective tooth structures.

  1. Influence of different staining beverages on color stability, surface roughness and microhardness of silorane and methacrylate-based composite resins.

    Science.gov (United States)

    Karaman, Emel; Tuncer, Duygu; Firat, Esra; Ozdemir, Oguz Suleyman; Karahan, Sevilay

    2014-05-01

    To investigate the influence of different staining beverages on color stability, surface roughness and microhardness of silorane and methacrylate-based composite resins. Three different composite resins (Filtek Silorane, Filtek P60, Filtek Supreme XT) were tested. Thirty cylindrical specimens (10 × 2 mm) per material were prepared and polished with a series of aluminum-oxide polishing disks. Each group was then randomly subdivided into three groups according to the test beverages: distilled water (control), cola and coffee. The samples were immersed into different beverages for 15 days. Color, surface roughness and microhardness values were measured by a spectrophotometer, prophylometer and Vickers hardness device respectively, at baseline and after 15 days. The data were subjected to statistical analysis. Immersion in coffee resulted in a significant discoloration for all the composites tested, although the color change was lower in Filtek Silorane than that of MBCs (p composites tested showed similar surface roughness changes after immersion in different beverages (p > 0.05). Besides coffee caused more roughness change than others. Immersion in coffee caused highest microhardness change in Filtek Supreme XT (p resin composites, depending on the characteristics of the materials.

  2. Formation of functionalized nanoclusters by solvent evaporation and their effect on the physicochemical properties of dental composite resins.

    Science.gov (United States)

    Rodríguez, Henry A; Giraldo, Luis F; Casanova, Herley

    2015-07-01

    The aim of this work was to study the effect of silica nanoclusters (SiNC), obtained by a solvent evaporation method and functionalized by 3-methacryloxypropyltrimethoxysilane (MPS) and MPS+octyltrimethoxysilane (OTMS) (50/50wt/wt), on the rheological, mechanical and sorption properties of urethane dimethylacrylate (UDMA)/triethylenglycol dimethacrylate (TEGDMA) (80/20wt/wt) resins blend. Silica nanoparticles (SiNP) were silanized with MPS or MPS+OTMS (50/50wt/wt) and incorporated in an UDMA-isopropanol mix to produce functionalized silica nanoclusters after evaporating the isopropanol. The effect of functionalized SiNC on resins rheological properties was determined by large and small deformation tests. Mechanical, thermal, sorption and solubility properties were evaluated for composite materials. The UDMA/TEGDMA (80/20wt/wt) resins blend with added SiNC (ca. 350nm) and functionalized with MPS showed a Newtonian flow behavior associated to their spheroidal shape, whereas the resins blend with nanoclusters silanized with MPS+OTMS (50/50wt/wt) (ca. 400nm) showed a shear-thinning behavior due to nanoclusters irregular shape. Composite materials prepared with bare silica nanoclusters showed lower compressive strength than functionalized silica nanoclusters. MPS functionalized nanoclusters showed better mechanical properties but higher water sorption than functionalized nanoclusters with both silane coupling agents, MPS and OTMS. The solvent evaporation method applied to functionalized nanoparticles showed to be an alternative way to the sinterization method for producing nanoclusters, which improved some dental composite mechanical properties and reduced water sorption. The shape of functionalized silica nanoclusters showed to have influence on the rheological properties of SiNC resin suspensions and the mechanical and sorption properties of light cured composites. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  3. Natural tooth pontic with splinting of periodontally weakened teeth using fiber-reinforced composite resin

    Directory of Open Access Journals (Sweden)

    Gauri Srinidhi

    2014-01-01

    Full Text Available Replacement of missing anterior teeth due to periodontal reasons is challenging due to the poor support of abutment teeth. This prevents the use of fixed partial dentures (FPDs. Fiber-reinforced splinting provides a viable alternative to the dentist while choosing a treatment plan in replacing missing anterior teeth in periodontally compromised patients as opposed to conventional modalities like FPDs or removable partial dentures. Replacing missing teeth using either patient′s own tooth or a denture tooth as pontic can be done by splinting adjacent teeth with fiber reinforced composite. The splinting has an additional advantage of stabilizing adjacent mobile teeth. This case report details the case selection, procedure with follow-up of a case where the natural extracted tooth of the patient was used as pontic to replace a missing anterior tooth. The splinting was done with fiber reinforced composite resin. Fiber-reinforced composite resin splinting of patient′s extracted natural tooth is economical, fast, and easy to use chairside technique with the added benefit of periodontal stabilization.

  4. Fracture Strength of Indirect Resin Composite Laminates to Teeth with Existing Restorations : An Evaluation of Conditioning Protocols

    NARCIS (Netherlands)

    Mese, Ayse; Ozcan, Mutlu

    2009-01-01

    Purpose: This study evaluated the fracture strength and failure types of indirect resin-based composite laminates bonded to teeth with aged Class III composite restorations that were conditioned according to various protocols. Materials and Methods: Maxillary central incisors (N = 60) with

  5. [Influence of retainer design on fixation strength of resin-bonded glass fiber reinforced composite fixed cantilever dentures].

    Science.gov (United States)

    Petrikas, O A; Voroshilin, Iu G; Petrikas, I V

    2013-01-01

    Fiber-reinforced composite (FRC) fixed partial dentures (FPD) have become an accepted part of the restorative dentist's armamentarium. The aim of this study was to evaluate in vitro the influence of retainer design on the strength of two-unit cantilever resin-bonded glass FRC-FPDs. Four retainer designs were tested: a dual wing, a dual wing + horizontal groove, a dual wing + occlusal rest and a step-box. Of each design on 7 human mandibular molars, FRC-FPDs of a premolar size were produced. The FRC framework was made of resin Revolution (Kerr) impregnated glass fibers (GlasSpan, GlasSpan) and veneered with hybrid resin composite (Charisma, Kulzer). Revolution (Kerr) was used as resin luting cement. FRC-FPDs were loaded to failure in a universal testing machine. T (Student's)-test was used to evaluate the data. The four designs were analyzed with finite element analysis (FEA) to reveal the stress distribution within the tooth/restoration complex. Significantly lower fracture strengths were observed with inlay-retained FPDs (step-box: 172±11 N) compared to wing-retained FPDs (poptimal design for replacement of a single premolar by means of a two-unit cantilever FRC-FPDs.

  6. Effects of leached components from a hybrid resin composite on the reproductive system of male mice

    Directory of Open Access Journals (Sweden)

    Taher Akbari Saeed

    2012-01-01

    Full Text Available Background and Aims: There is concern that leached components from dental composites may cause adverse changes in the reproductive health. This study aimed to assess the effects of leached components from a hybrid resin composite on the reproductive system of male mice.Materials and Methods: In the present animal study, twenty adult Syrian male mice were divided into two groups of 10 mice each. In the test group, components which leached from samples made from Filtek Z250 resin composite into 75% ethanol were daily administered to the mice for 28 days. In the control group, the procedure was repeated in the same way as the test group but without placing composite samples in the solution. Then, the body weight, weights of paired testes, Gonado Somatic Index, sperm viability, sperm motility, epididymal sperm reserve and daily sperm production were recorded. Four male mice in each group were mated with untreated female mice for 10 days. After that, the number of pregnant females and number of infants were recorded. The data were analyzed using repeated measures ANOVA, Chi-square test and t-test.Results: There was a significant reduction in the sperm viability and sperm motility of male mice in the test group compared to the control group (P=0.001. There was no any significant differences in other parameters between two groups (P>0.05.Conclusion: This study showed that the leached components from resin composites cannot cause infertility but they could potentially cause some adverse effects on the reproductive system of male mice.

  7. The effect of fiber dowel heights in resin composite cores on restoration failures of endodontically treated teeth.

    Science.gov (United States)

    Mekayarajjananonth, Trakol; Chitcharus, Nattinee; Winkler, Sheldon; Bogert, Meredith C

    2009-01-01

    In vitro and in vivo testing suggest that fiber posts may reduce the incidence of root fractures of endodontically treated teeth. The purpose of this in vitro study was to compare the effect of fiber post height in resin composite cores on the fracture resistance of endodontically treated teeth. Forty maxillary central incisors were randomly divided into 2 control groups (Groups 1 and 2) of 5 teeth each, and 3 experimental groups (Groups 3, 4, and 5) of 10 teeth each. The teeth in Group 1 had their opening restored with composite resin, the teeth in Group 2 were restored with quartz fiber posts without resin composite cores, and the teeth in Groups 3, 4, and 5 were restored with quartz fiber posts of 2, 4, and 6 mm high, respectively, in 6-mm resin composite cores. Ceramic crowns were fabricated for the specimens. Specimens were positioned in a mounting device and aligned at a 130-degree angle to the long axis of each tooth. A universal testing machine was used to apply constant load at a crosshead speed of 0.5 mm/min until failure occurred. The highest fracture load and mode of failure of each specimen was recorded. The highest fracture resistance force was observed in Group 2 (290.38 +/- 48.45 N) and decreased, respectively, in Group 1 (238.98 +/-26.26 N), Group 5 (228.35 +/-58.79 N), Group 4 (221.43 +/-38.74 N), and Group 3 (199.05 +/-58.00 N). According to one-way analysis of variance (ANOVA) and Duncan's test (P teeth should be restored with the longest possible post height while preserving maximum tooth structure.

  8. Qualitative Beam Profiling of Light Curing Units for Resin Based Composites.

    Science.gov (United States)

    Haenel, Thomas; Hausnerová, Berenika; Steinhaus, Johannes; Moeginger, Ing Bernhard

    2016-12-01

    This study investigates two technically simple methods to determine the irradiance distribution of light curing units that governs the performance of a visible-light curing resin-based composites. Insufficient light irradiation leads to under-cured composites with poor mechanical properties and elution of residual monomers. The unknown irradiance distribution and its effect on the final restoration are the main critical issues requiring highly sophisticated experimental equipment. The study shows that irradiance distributions of LCUs can easily be determined qualitatively with generally available equipment. This significantly helps dentists in practices to be informed about the homogeneity of the curing lights. Copyright© 2016 Dennis Barber Ltd.

  9. Color stability of sealed composite resin restorative materials after ultraviolet artificial aging and immersion in staining solutions.

    Science.gov (United States)

    Catelan, Anderson; Briso, André Luiz Fraga; Sundfeld, Renato Hermann; Goiato, Marcelo Coelho; dos Santos, Paulo Henrique

    2011-04-01

    The color alteration of resin-based materials is one of the most common reasons to replace esthetic dental restorations. This study assessed the influence of surface sealant (Biscover) on the color stability of nanofilled (Supreme XT) and microhybrid (Vit-l-escence and Opallis) composite resins after artificial aging. One hundred disc-shaped (6 × 1.5 mm) specimens were made for each composite resin. After 24 hours, all specimens were polished and sealant was applied to 50 specimens of each material. Baseline color was measured according to the CIE L*a*b* system using a reflection spectrophotometer. Ten specimens of each group were aged for 252 h in an ultraviolet (UV)-accelerated aging chamber or immersed for 4 weeks in cola soft drink, orange juice, red wine staining solutions or distilled water as control. Color difference (ΔE) after aging was calculated based on the color coordinates before (baseline) and after aging/staining treatment. Data were analyzed with 2-way ANOVA and Fisher's test (α=.05). The results showed significant changes in color after artificial aging in all the groups (Paging, and the cola soft drink. The lowest values of ΔE were found for specimens stored in distilled water. All composite resins showed some color alteration after the aging methods. The surface sealant did not alter the color stability of the tested materials. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  10. Influence of surface sealant on the translucency of composite resin: effect of immersion time and immersion media

    Directory of Open Access Journals (Sweden)

    Patrícia Petromilli Nordi Sasso Garcia

    2008-06-01

    Full Text Available This study evaluated the effect of surface sealant on the translucency of composite resin immersed in different solutions. The study involved the following materials: Charisma, Fortify and coffee, Coca-Cola®, tea and artificial saliva as solutions. Sixty-four specimens (n = 8 were manufactured and immersed in artificial saliva at 37 ± 1 °C. Samples were immersed in the solutions for three times a day and re-immersed in artificial saliva until the translucency readings. The measurements were carried out at nine times: T1 - 24 hours after specimen preparation, T2 - 24 hours after immersion in the solutions, T3 - 48 hours and T4 to T9 - 7, 14, 21, 30, 60 and 90 days, respectively, after immersion. The translucency values were measured using a JOUAN device. The results were subjected to ANOVA and Tukey's test at 5%. The surface sealant was not able to protect the composite resin against staining, the coffee showed the strongest staining action, followed by tea and regarding immersion time, a significant alteration was noted in the translucency of composite resin after 21 days.

  11. Effect of Ultrasonic Versus Manual Cementation on the Fracture Strength of Resin Composite Laminates

    NARCIS (Netherlands)

    Ozcan, M.; Mese, A.

    2009-01-01

    This study evaluated the effect of conventional versus ultrasonic cementation techniques on the fracture strength of resin composite laminates. In addition, the failure modes were assessed. Window-type preparations I mm above the cemento-enamel junction were made on intact human maxillary central

  12. Bond strength of selected composite resin-cements to zirconium-oxide ceramic

    Science.gov (United States)

    Fons-Font, Antonio; Amigó-Borrás, Vicente; Granell-Ruiz, María; Busquets-Mataix, David; Panadero, Rubén A.; Solá-Ruiz, Maria F.

    2013-01-01

    Objectives: The aim of this study was to evaluate bond strengths of zirconium-oxide (zirconia) ceramic and a selection of different composite resin cements. Study Design: 130 Lava TM cylinders were fabricated. The cylinders were sandblasted with 80 µm aluminium oxide or silica coated with CoJet Sand. Silane, and bonding agent and/or Clearfil Ceramic Primer were applied. One hundred thirty composite cement cylinders, comprising two dual-polymerizing (Variolink II and Panavia F) and two autopolymerizing (Rely X and Multilink) resins were bonded to the ceramic samples. A shear test was conducted, followed by an optical microscopy study to identify the location and type of failure, an electron microscopy study (SEM and TEM) and statistical analysis using the Kruskal-Wallis test for more than two independent samples and Mann-Whitney for two independent samples. Given the large number of combinations, Bonferroni correction was applied (α=0.001). Results: Dual-polymerizing cements provided better adhesion values (11.7 MPa) than the autopolymerizing (7.47 MPa) (p-value M-Wzirconium-oxide ceramic, creating a more rough and retentive surface, thus providing an improved micromechanical interlocking between the cement and the ceramic. Key words:Shear bond strength, silica coating, surface treatment, zirconia ceramics, phosphate monomer. PMID:22926485

  13. Efficiency of polymerization of bulk-fill composite resins: a systematic review.

    Science.gov (United States)

    Reis, André Figueiredo; Vestphal, Mariana; Amaral, Roberto Cesar do; Rodrigues, José Augusto; Roulet, Jean-François; Roscoe, Marina Guimarães

    2017-08-28

    This systematic review assessed the literature to evaluate the efficiency of polymerization of bulk-fill composite resins at 4 mm restoration depth. PubMed, Cochrane, Scopus and Web of Science databases were searched with no restrictions on year, publication status, or article's language. Selection criteria included studies that evaluated bulk-fill composite resin when inserted in a minimum thickness of 4 mm, followed by curing according to the manufacturers' instructions; presented sound statistical data; and comparison with a control group and/or a reference measurement of quality of polymerization. The evidence level was evaluated by qualitative scoring system and classified as high-, moderate- and low- evidence level. A total of 534 articles were retrieved in the initial search. After the review process, only 10 full-text articles met the inclusion criteria. Most articles included (80%) were classified as high evidence level. Among several techniques, microhardness was the most frequently method performed by the studies included in this systematic review. Irrespective to the "in vitro" method performed, bulk fill RBCs were partially likely to fulfill the important requirement regarding properly curing in 4 mm of cavity depth measured by depth of cure and / or degree of conversion. In general, low viscosities BFCs performed better regarding polymerization efficiency compared to the high viscosities BFCs.

  14. The influence of storage time and pH variation on water sorption by different composite resins.

    Science.gov (United States)

    Gusmão, George Mário de Araújo Silva; De Queiroz, Thiago Vinicius Veras; Pompeu, Guilherme Ferrer; Menezes Filho, Paulo Fonseca; da Silva, Cláudio Heliomar Vicente

    2013-01-01

    The objective of this work was to assess the influence of storage time and pH cycling on water sorption by different composite resins. Nine resin brands were selected and divided into groups: G1-ROK (SDI), G2-ICE (SDI), G3-GLACIER (SDI), G4-Z350 (3M/ESPE), G5-Z250 (3M/ESPE), G6-TPH 3 (DENTSPLY), G7-ESTHET X (DENTSPLY), G8-SUPRAFILL (SSWHITE), and G9-MASTERFILL (BIODINΒMICS). Ninety specimens, ten per group, were obtained using an aluminum matrix. Specimens measured 10 mm diameter × 2 mm width. The groups were divided into subgroups according to the immersion solution: A - control (n = 05) stored in artificial saliva pH = 7.0 and B-test (n = 05) submitted to seven consecutive days of pH cycling (cariogenic challenger) that consisted of immersion in a pH° = 4.3 solution for 6 h followed by immersion in a pH¹ =7.0 solution for 18 h and stored in artificial saliva pH = 7.0 until the end of the experiment. The specimens were weighed on six occasions: T 0 (after fabrication), T 1 (24 h), T 2 (7 days), T 3 (15 days), T 4 (30 days), T 5 (60 days), and then analyzed. The water sorption was determined by the weight difference between the specimens at the time intervals. The mean weight gain was exactly the same for both the subgroups within group G4. The highest means for the control subgroup were found in groups: G1, G5, G7, G8, and G9. For the pH cycling subgroup, the highest means were found in G2, G3, and G6; however, significant differences between the subgroups compared to the mean-weight gain were found for G1, G5, and G7. The water sorption of composite resins is dependent upon their storage time. The pH cycling created a significant impact on resins G1, G5, and G7. The sorption and solubility of composite resins vary according to their chemical composition.

  15. Vertically aligned TiO2 nanorods-woven carbon fiber for reinforcement of both mechanical and anti-wear properties in resin composite

    Science.gov (United States)

    Fei, Jie; Zhang, Chao; Luo, Dan; Cui, Yali; Li, Hejun; Lu, Zhaoqing; Huang, Jianfeng

    2018-03-01

    A series of TiO2 nanorods were successfully grown on woven carbon fiber by hydrothermal method to reinforce the resin composite. The TiO2 nanorods improved the mechanical interlocking among woven carbon fibers and resin matrix, resulting in better fibers/resin interfacial bonding. Compared with desized-woven carbon fiber, the uniform TiO2 nanorods array resulted in an improvement of 84.3% and 73.9% in the tensile and flexural strength of the composite. However, the disorderly TiO2 nanorods on woven carbon fiber leaded to an insignificant promotion of the mechanical strength. The enhanced performance of well-proportioned TiO2 nanorods-woven carbon fiber was also reflected in the nearly 56% decrease of wear rate, comparing to traditional woven carbon fiber reinforced composite.

  16. Effect of Camphorquinone Concentration in Physical-Mechanical Properties of Experimental Flowable Resin Composites

    Directory of Open Access Journals (Sweden)

    Dayany da Silva Alves Maciel

    2018-01-01

    Full Text Available The aim of this study was to evaluate the effect of camphorquinone concentration in physical-mechanical properties of experimental flowable composites in order to find the concentration that results in maximum conversion, balanced mechanical strength, and minimum shrinkage stress. Model composites based on BISGMA/TEGDMA with 70% wt filler loading were prepared containing different concentrations of camphorquinone (CQ on resin matrix (0.25%, 0.50%, 1%, 1.50%, and 2% by weight. Degree of conversion was determined by FTIR. Surface hardness was assessed before and after 24 h ethanol storage and softening rate was determined. Depth of cure was determined by Knoop hardness evaluation at different depths. Color was assessed by reflectance spectrophotometer, employing the CIE-Lab system. Flexural strength and elastic modulus were determined by a three-point bending test. Shrinkage stress was determined in a Universal Testing Machine in a high compliance system. Data were submitted to ANOVA and Tukey’s test (α = 0.05. The increase in CQ concentration caused a significant increase on flexural strength and luminosity of composites. Surface hardness was not affected by the concentration of CQ. Composite containing 0.25% wt CQ showed lower elastic modulus and shrinkage stress when compared to others. Depth of cure was 3 mm for composite containing 1% CQ and 2 mm for the other tested composites. Degree of conversion was inversely correlated with softening rate and directly correlated with elastic modulus and shrinkage stress. In conclusion, CQ concentration affects polymerization characteristics and mechanical strength of composites. The concentration of CQ in flowable composite for optimized polymerization and properties was 1% wt of the resin matrix, which allows adequate balance among degree of conversion, depth of cure, mechanical properties, and color characteristics of these materials.

  17. Development of new and improved polymer matrix resin systems, phase 1

    Science.gov (United States)

    Hsu, M. S.

    1983-01-01

    Vinystilbazole (vinylstryrylpyridine) and vinylpolystyrulpyridine were prepared for the purpose of modifying bismaleimide composite resins. Cure studies of resins systems were investigated by differential scanning calorimetry. The vinylstyrylpyridine-modified bismaleimide composite resins were found to have lower cure and gel temperatures, and shorter cure times than the corresponding unmodified composite resins. The resin systems were reinforced with commercially avialable satin-weave carbon cloth. Prepregs were fabricated by solvent or hot melt techniques. Thermal stability, flammability, moisture absorption, and mechanical properties of the composites (such as flexural strength, modulus, tensile and short beam shear strength) were determined. Composite laminates showed substantial improvements in both processability and mechanical properties compared to he bismaleimide control systems. The vinylstyrylpyridine modified bismaleimide resins can be used as advanced matrix resins for graphite secondary structures where ease of processing, fireworthiness, and high temperature stability are required for aerospace applications.

  18. Flowable Resin Composites: A Systematic Review and Clinical Considerations

    Science.gov (United States)

    Rodrigues, Jean C.

    2015-01-01

    Background Little is known about flowable composite materials. Most literature mentions conventional composite materials at large, giving minimal emphasis to flowables in particular. This paper briefly gives an in depth insight to the multiple facets of this versatile material. Aim To exclusively review the most salient features of flowable composite materials in comparison to conventional composites and to give clinicians a detailed understanding of the advantages, drawbacks, indications and contraindications based on composition and physical/mechanical properties. Methodology Data Sources: A thorough literature search from the year 1996 up to January 2015 was done on PubMed Central, The Cochrane Library, Science Direct, Wiley Online Library, and Google Scholar. Grey literature (pending patents, technical reports etc.) was also screened. The search terms used were “dental flowable resin composites”. Search Strategy After omitting the duplicates/repetitions, a total of 491 full text articles were assessed. As including all articles were out of the scope of this paper. Only relevant articles that fulfilled the reviewer’s objectives {mentioning indications, contraindications, applications, assessment of physical/mechanical/biological properties (in vitro/ in vivo /ex vivo)} were considered. A total of 92 full text articles were selected. Conclusion Flowable composites exhibit a variable composition and consequently variable mechanical/ physical properties. Clinicians must be aware of this aspect to make a proper material selection based on specific properties and indications of each material relevant to a particular clinical situation. PMID:26266238

  19. The effect of polishing technique on 3-D surface roughness and gloss of dental restorative resin composites.

    Science.gov (United States)

    Ereifej, N S; Oweis, Y G; Eliades, G

    2013-01-01

    The aim of this study was to compare surface roughness and gloss of resin composites polished using different polishing systems. Five resin composites were investigated: Filtek Silorane (FS), IPS Empress Direct (IP), Clearfil Majesty Posterior (CM), Premise (PM), and Estelite Sigma (ES). Twenty-five disk specimens were prepared from each material, divided into five groups, each polished with one of the following methods: Opti1Step (OS), OptiDisc (OD), Kenda CGI (KD), Pogo (PG), or metallurgical polishing (ML). Gloss and roughness parameters (Sa, Sz, Sq, and St) were evaluated by 60°-angle glossimetry and white-light interferometric profilometry. Two-way analysis of variance was used to detect differences in different materials and polishing techniques. Regression and correlation analyses were performed to examine correlations between roughness and gloss. Significant differences in roughness parameters and gloss were found according to the material, type of polishing, and material/polishing technique (pgloss was recorded for PM/ML (88.4 [2.3]) and lowest for FS/KD (30.3 [5.7]). All roughness parameters were significantly correlated with gloss (r= 0.871, 0.846, 0.713, and 0.707 for Sa, Sq, Sz, St, and gloss, respectively). It was concluded that the polishing procedure and the type of composite can have significant impacts on surface roughness and gloss of resin composites.

  20. Cytotoxicity and cytokine expression induced by silorane and methacrylate-based composite resins.

    Science.gov (United States)

    Longo, Daniele Lucca; Paula-Silva, Francisco Wanderley Garcia; Faccioli, Lucia Helena; Gatón-Hernández, Patrícia Maria; Queiroz, Alexandra Mussolino de; Silva, Léa Assed Bezerra da

    2016-01-01

    The aim of this study was to evaluate cytotoxicity and cytokine production induced by light-cured or non-light-cured methacrylate-based and silorane composite resins in RAW 264.7 macrophages. Cells were stimulated with the extracts from light-cured or non-light-cured composite resins. After incubation for 24 h, cytotoxicity was assessed with the lactate dehydrogenase (LDH) and methyl thiazolyl tetrazolium (MTT) assays, and total protein was quantified using the Lowry method. TNF-α detection was examined with an enzyme-linked immunosorbent assay (ELISA) conducted with cell supernatants after cell stimulation for 6, 12, and 24 h. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's post hoc test (α=0.05). KaloreTM and FiltekTM Silorane were cytotoxic with or without light curing (p0.05). However, after 24 h FiltekTM Silorane inhibited the production of TNF-α (p<0.05). KaloreTM and FiltekTM Silorane were cytotoxic regardless of light curing. The extract obtained from KaloreTM after 15 days of incubation stimulated the production of TNF-α, unlike that obtained from FiltekTM Silorane.

  1. Effects of cold light bleaching on the color stability of composite resins

    Science.gov (United States)

    Cao, Liqun; Huang, Lijuan; Wu, Meisheng; Wei, Hua; Zhao, Shouliang

    2015-01-01

    To evaluate the effects of cold light bleaching on the color stability of four restorations using a thermocycling stain challenge. 160 specimens (10 mm in diameter and 2 mm thick) were fabricated from 4 composite resins (Gradia Direct-A, Z350XT, Premisa, and Précis) and divided into 4 subgroups. Color was assessed according to the CIEL*a*b* color scale at baseline, after the first cycle of bleaching, after thermocycling stain challenges, and after the second cycle of bleaching. Mean values were compared using three-way analysis of variance, and multiple comparisons of the mean values were performed using the Tukey-Kramer test. All groups showed significant color changes after stain challenge, the color change was more significant in Gradia Direct and Z350XT than in Premisa and Précis. After the second cycle of bleaching, color mostly recovered to its original values. The color stability of Gradia Direct and Z350XT was inferior to that of Premisa and Précis. The discoloration of composite resin materials can be partly removed after cold light bleaching. PMID:26309549

  2. The effect of various primers on shear bond strength of zirconia ceramic and resin composite.

    Science.gov (United States)

    Sanohkan, Sasiwimol; Kukiattrakoon, Boonlert; Larpboonphol, Narongrit; Sae-Yib, Taewalit; Jampa, Thibet; Manoppan, Satawat

    2013-11-01

    To determine the in vitro shear bond strengths (SBS) of zirconia ceramic to resin composite after various primer treatments. Forty zirconia ceramic (Zeno, Wieland Dental) specimens (10 mm in diameter and 2 mm thick) were prepared, sandblasted with 50 μm alumina, and divided into four groups (n = 10). Three experimental groups were surface treated with three primers; CP (RelyX Ceramic Primer, 3M ESPE), AP (Alloy Primer, Kuraray Medical), and MP (Monobond Plus, Ivoclar Vivadent AG). One group was not treated and served as the control. All specimens were bonded to a resin composite (Filtek Supreme XT, 3M ESPE) cylinder with an adhesive system (Adper Scotchbond Multi-Purpose Plus Adhesive, 3M ESPE) and then stored in 100% humidity at 37°C for 24 h before SBS testing in a universal testing machine. Mean SBS (MPa) were analyzed with one-way analysis of variance (ANOVA) and the Tukey's Honestly Significant Difference (HSD) test (α = 0.05). Group AP yielded the highest mean and standard deviation (SD) value of SBS (16.8 ± 2.5 MPa) and Group C presented the lowest mean and SD value (15.4 ± 1.6 MPa). The SBS did not differ significantly among the groups (P = 0.079). Within the limitations of this study, the SBS values between zirconia ceramic to resin composite using various primers and untreated surface were not significantly different.

  3. A laboratory investigation of colour changes in two contemporary resin composites on exposure to spices.

    Science.gov (United States)

    Yew, H Z; Berekally, T L; Richards, L C

    2013-12-01

    The aim of this study was to evaluate colour stability upon exposure to spices of a nano-filled and a micro-hybrid resin composite finished either with Sof-Lex™ discs (SLD) or against plastic strips (PS). Forty cylindrical specimens of 3 mm thickness were fabricated from Filtek Supreme XT ™ (FS) and Gradia Direct X™ (GD). The top surface of each specimen was polished with SLD while the bottom surface was finished against PS. All samples were immersed in staining solutions (0.1% weight turmeric, paprika and tamarind) and distilled water at 37 °C. Colour after 0, 24, 72 and 168 hours of immersion was recorded with a reflection spectrophotometer using CIE L*a*b* parameters and the results were statistically analysed with repeated measures of ANOVA and Bonferroni post hoc tests. Among all the staining solutions tested, the highest colour deviation was obtained in the turmeric group. FS finished against PS showed significantly more colour changes compared to specimens polished with SLD, while GD finished against PS were found to be more resistant to colour changes. Within the limitations of this study all the spices tested have the potential to stain resin composites with turmeric causing the most significant discolouration. Micro-hybrid and nano-filled resin composites appeared to respond differently to staining by spices when either finished with PS or polished with SLD. © 2013 Australian Dental Association.

  4. Conjugation of diisocyanate side chains to dimethacrylate reduces polymerization shrinkage and increases the hardness of composite resins

    Directory of Open Access Journals (Sweden)

    Yih-Dean Jan

    2014-04-01

    Conclusion: Conjugation of diisocyanate side chains to dimethacrylate represents an effective means of reducing polymerization shrinkage and increasing the surface hardness of dental composite resins.

  5. Simultaneous determination of components released from dental composite resins in human saliva by liquid chromatography/multiple-stage ion trap mass spectrometry.

    Science.gov (United States)

    Hsu, Wei-Yi; Wang, Ven-Shing; Lai, Chien-Chen; Tsai, Fuu-Jen

    2012-02-01

    Dental composite resins are widely used for fixing teeth; however, the monomers used in dental composite resins have been found to be cytotoxic and genotoxic, namely triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), and bisphenol A glycol dimethacrylate (Bis-GMA). In this study, we incubated dental composite resins with human saliva for demonstrating the released monomers and biodegradation products. A simple saliva sample dilution method without purification or derivatization was used for quantification. We found that liquid chromatography coupled with multiple-stage ion trap mass spectrometry (LC-MS(n) ) operated in selected reaction monitoring (SRM) mode was able to separate the three monomers within 10 min. The calibration curves were linear (R² >0.996) over a wide range for each monomer in saliva: TEGDMA, 5-500 ppb; UDMA, 5-100 ppb, and Bis-GMA, 5-700 ppb. Furthermore, several biodegradation products were discovered with data-dependent MS/MS scan techniques. Although TEGMA degradation products have previously been reported, we identified two previously unknown UDMA degradation products. The LC-MS/MS method developed in this study was able to successfully quantify monomers and their principal biodegradation products from dental composite resins in human saliva. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Post-cure depth of cure of bulk fill dental resin-composites.

    Science.gov (United States)

    Alrahlah, A; Silikas, N; Watts, D C

    2014-02-01

    To determine the post-cure depth of cure of bulk fill resin composites through using Vickers hardness profiles (VHN). Five bulk fill composite materials were examined: Tetric EvoCeram(®) Bulk Fill, X-tra base, Venus(®) Bulk Fill, Filtek™ Bulk Fill, SonicFill™. Three specimens of each material type were prepared in stainless steel molds which contained a slot of dimensions (15 mm × 4 mm × 2 mm), and a top plate. The molds were irradiated from one end. All specimens were stored at 37°C for 24h, before measurement. The Vickers hardness was measured as a function of depth of material, at 0.3mm intervals. Data were analysed by one-way ANOVA using Tukey post hoc tests (α=0.05). The maximum VHN ranged from 37.8 to 77.4, whilst the VHN at 80% of max.VHN ranged from 30.4 to 61.9. The depth corresponding to 80% of max.VHN, ranged from 4.14 to 5.03 mm. One-way ANOVA showed statistically significant differences between materials for all parameters tested. SonicFill exhibited the highest VHN (pFill the lowest (p≤0.001). SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure (5.03 and 4.47 mm, respectively) and was significant's different from X-tra base, Venus Bulk Fill and Filtek Bulk Fill (p≤0.016). Linear regression confirmed a positive regression between max.VHN and filler loading (r(2)=0.94). Bulk fill resin composites can be cured to an acceptable post-cure depth, according to the manufacturers' claims. SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure among the composites examined. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  7. Influence of curing rate of resin composite on the bond strength to dentin

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Asmussen, E; Peutzfeldt, A

    2007-01-01

    @ 1000 mW/cm2) for all groups. A split Teflon mold was clamped to the treated dentin surface and filled with resin composite. The rate of cure was varied, using one of four LED-curing units of different power densities. The rate of cure was also varied using the continuous or pulse-delay mode....... In continuous curing mode, in order to give an energy density totaling 16 J/cm2, the power densities (1000, 720, 550, 200 mW/cm2) emitted by the various curing units were compensated for by the light curing period (16, 22, 29 or 80 seconds). In the pulse-delay curing mode, two seconds of light curing at one...... of the four power densities was followed by a one-minute interval, after which light cure was completed (14, 29, 27 or 78 seconds), likewise, giving a total energy density of 16 J/cm2. The specimens produced for each of the eight curing protocols and two resin composites (Tetric EvoCeram, Ivoclar Vivadent...

  8. Resin Viscosity Influence on Fiber Compaction in Tapered Resin Injection Pultrusion Manufacturing

    Science.gov (United States)

    Masuram, N. B.; Roux, J. A.; Jeswani, A. L.

    2018-06-01

    Viscosity of the liquid resin effects the chemical and mechanical properties of the pultruded composite. In resin injection pultrusion manufacturing the liquid resin is injected into a specially designed tapered injection chamber through the injection slots present on top and bottom of the chamber. The resin is injected at a pressure so as to completely wetout the fiber reinforcements inside the tapered injection chamber. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall towards the center of chamber causing compaction of the fiber reinforcements. The fibers are squeezed together due to compaction, making resin penetration more difficult; thus higher resin injection pressures are required to efficaciously penetrate through the compacted fibers and achieve complete wetout. The impact of resin viscosity on resin flow, fiber compaction, wetout and on the final product is further discussed. Injection chamber design predominantly effects the resin flow inside the chamber and the minimum injection pressure required to completely wet the fibers. Therefore, a desirable injection chamber design is such that wetout occurs at lower injection pressures and at low internal pressures inside the injection chamber.

  9. The effect of different beverages on surface hardness of nanohybrid resin composite and giomer

    Science.gov (United States)

    Tanthanuch, Saijai; Kukiattrakoon, Boonlert; Siriporananon, Chantima; Ornprasert, Nawanda; Mettasitthikorn, Wathu; Likhitpreeda, Salinla; Waewsanga, Sulawan

    2014-01-01

    Aims: To investigate the effects of five beverages (apple cider, orange juice, Coca-Cola, coffee, and beer) on microhardness and surface characteristic changes of nanohybrid resin composite and giomer. Materials and Methods: Ninety-three specimens of each resin composite and giomer were prepared. Before immersion, baseline data of Vicker's microhardness was recorded and surface characteristics were examined using scanning electron microscopy (SEM). Five groups of discs (n = 18) were alternately immersed in 25 mL of each beverage for 5 s and in 25 mL of artificial saliva for 5 s for 10 cycles. Specimens were then stored in artificial saliva for 24 h. This process was repeated for 28 days. After immersion, specimens were evaluated and data were analyzed by two-way repeated analysis of variance (ANOVA), Tukey's honestly significant difference (HSD), and a t-test (α = 0.05). Results: Microhardness of all groups significantly decreased after being immersed in the tested beverages (P < 0.05). SEM photomicrographs presented surface degradation of all groups. Conclusions: The effect of these beverages on the surface of both restorative materials also depended upon the exposure time and chemical composition of the restorative materials and beverages. PMID:24944451

  10. Process Optimization of Bismaleimide (BMI) Resin Infused Carbon Fiber Composite

    Science.gov (United States)

    Ehrlich, Joshua W.; Tate, LaNetra C.; Cox, Sarah B.; Taylor, Brian J.; Wright, M. Clara; Caraccio, Anne J.; Sampson, Jeffery W.

    2013-01-01

    Bismaleimide (BMI) resins are an attractive new addition to world-wide composite applications. This type of thermosetting polyimide provides several unique characteristics such as excellent physical property retention at elevated temperatures and in wet environments, constant electrical properties over a vast array of temperature settings, and nonflammability properties as well. This makes BMI a popular choice in advance composites and electronics applications [I]. Bismaleimide-2 (BMI-2) resin was used to infuse intermediate modulus 7 (IM7) based carbon fiber. Two panel configurations consisting of 4 plies with [+45deg, 90deg]2 and [0deg]4 orientations were fabricated. For tensile testing, a [90deg]4 configuration was tested by rotating the [0deg]4 configirration to lie orthogonal with the load direction of the test fixture. Curing of the BMI-2/IM7 system utilized an optimal infusion process which focused on the integration of the manufacturer-recommended ramp rates,. hold times, and cure temperatures. Completion of the cure cycle for the BMI-2/IM7 composite yielded a product with multiple surface voids determined through visual and metallographic observation. Although the curing cycle was the same for the three panellayups, the surface voids that remained within the material post-cure were different in abundance, shape, and size. For tensile testing, the [0deg]4 layup had a 19.9% and 21.7% greater average tensile strain performance compared to the [90deg]4 and [+45deg, 90deg, 90deg,-45degg] layups, respectively, at failure. For tensile stress performance, the [0deg]4 layup had a 5.8% and 34.0% greater average performance% than the [90deg]4 and [+45deg, 90deg, 90deg,-45deg] layups.

  11. The influence of mouthrinses and simulated toothbrushing on the surface roughness of a nanofilled composite resin

    Directory of Open Access Journals (Sweden)

    Keico Graciela Sano Trauth

    2012-06-01

    Full Text Available The aim of this study was to determine the influence of mouthrinses on the surface roughness of a nanofilled composite resin after toothbrushing. One hundred nanofilled composite resin specimens were prepared and randomly distributed into two groups-brushed and non-brushed-and then assigned to five subgroups, according to the mouthrinse solutions (n = 10: Colgate Plax Fresh Mint, Oral B, Cepacol, Colgate Plax, and artificial saliva. Each sample was immersed in 20 mL of the mouthrinses for 1 minute, 5 days per week, twice a day, for a 3-week period. The control group used in the study was one in which the specimens were not subjected to brushing and remained only in artificial saliva. Toothbrushing was performed once a week for 1 minute, for 3 weeks. Surface roughness measurements (Ra were performed after the immersion period and toothbrushing, by means of a profilometer. Data were analyzed by two-way ANOVA and Tukey's test. Analysis revealed that the association between toothbrushing and Colgate Plax Fresh Mint produced the lowest surface roughness (p < 0.05. All other groups tested (Oral B, Cepacol, Colgate Plax, artificial saliva exhibited no statistically significant differences between surfaces, whether subjected to toothbrushing or not (p < 0.05. It was concluded that the surface roughness of the nanofilled composite resin tested can be influenced by the mouthrinse associated with toothbrushing.

  12. Comparison of different polishing methods on the surface roughness of microhybrid, microfill, and nanofill composite resins.

    Science.gov (United States)

    Moda, Mariana D; Godas, André Gustavo de L; Fernandes, Juliana C; Suzuki, Thaís Y U; Guedes, Ana Paula A; Briso, André L F; Bedran-Russo, Ana Karina; Dos Santos, Paulo H

    2018-02-01

    The aim of the present study was to evaluate the effect of different polishing methods on the surface roughness of resin-based composites subjected to a thermocycling procedure. A total of 192 specimens were divided into 24 groups, according to composite materials (Filtek Z250, Point 4, Renamel Nanofill, Filtek Supreme Plus, Renamel Microfill, and Premise) and finishing and polishing systems (Sof-Lex Pop On, Super Snap, Flexidisc, and Flexidisc+Enamelize). The specimens were subjected to thermocycling (5000 cycles). Filtek Supreme Plus showed the lowest surface roughness values before thermocycling. After thermocycling, Filtek Supreme Plus continued to have the lowest surface roughness, with a statistically-significant difference for the other materials. After thermocycling, there was no statistically-significant difference among all the polishing techniques studied. The thermocycling was concluded as being able to change composite resins' surface roughness, whereas different finishing and polishing methods did not result in surface roughness changes after thermocycling. © 2017 John Wiley & Sons Australia, Ltd.

  13. Direct Resin Composite Restoration of Maxillary Central Incisors with Fractured Tooth Fragment Reattachment: Case Report.

    Science.gov (United States)

    Szmidt, Monika; Górski, Maciej; Barczak, Katarzyna; Buczkowska-Radlińska, Jadwiga

    This article presents a clinical protocol to reconstruct two accidentally damaged maxillary central incisors using composite resin material and a fractured tooth component. A patient was referred to the clinic with fracture of the two maxillary central incisors. Clinical examination revealed that both teeth were fractured in the middle third of the crown and that the fractures involved enamel and dentin with no pulp exposure. The patient had also suffered a lower lip laceration. When the lip was evaluated, a fractured fragment of the maxillary right central incisor was found inside the wound. The missing part of the tooth was replaced via adhesive attachment. Due to the damage of the fractured part of the maxillary left central incisor, direct composite restoration of this tooth was performed. With the advent of adhesive dentistry, the process of fragment reattachment has become simplified and more reliable. This procedure provides improved function, is faster to perform, and provides long-lasting effects, indicating that reattachment of a coronal fragment is a realistic alternative to placement of conventional resin composite restorations.

  14. A resin composite material containing an eugenol derivative for intracanal post cementation and core build-up restoration.

    Science.gov (United States)

    Almaroof, A; Rojo, L; Mannocci, F; Deb, S

    2016-02-01

    To formulate and evaluate new dual cured resin composite based on the inclusion of eugenyl methacrylate monomer (EgMA) with Bis-GMA/TEGDMA resin systems for intracanal post cementation and core build-up restoration of endodontically treated teeth. EgMA was synthesized and incorporated at 5% (BTEg5) or 10% (BTEg10) into dual-cure formulations. Curing properties, viscosity, Tg, radiopacity, static and dynamic mechanical properties of the composites were determined and compared with Clearfil™DC Core-Plus, a commercial dual-cure, two-component composite. Statistical analysis of the data was performed with ANOVA and the Tukey's post-hoc test. The experimental composites were successfully prepared, which exhibited excellent curing depths of 4.9, 4.7 and 4.2 mm for BTEg0, BTEg5 and BTEg10 respectively, which were significantly higher than Clearfil™DC. However, the inclusion of EgMA initially led to a lower degree of cure, which increased when measured at 24 h with values comparable to formulations without EgMA, indicating post-curing. The inclusion of EgMA also lowered the polymerization exotherm thereby reducing the potential of thermal damage to host tissue. Both thermal and viscoelastic analyses confirmed the ability of the monomer to reduce the stiffness of the composites by forming a branched network. The compressive strength of BTEg5 was significantly higher than the control whilst flexural strength increased significantly from 95.9 to 114.8 MPa (BTEg5) and 121.9 MPa (BTEg10). Radiopacity of the composites was equivalent to ∼3 mm Al allowing efficient diagnosis. The incorporation of EgMA within polymerizable formulations provides a novel approach to prepare reinforced resin composite material for intracanal post cementation and core build-up and the potential to impart antibacterial properties of eugenol to endodontic restorations. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Gamma Radiation -Induced Preparation of Polymeric Composite Resins and their Structure Assignments

    International Nuclear Information System (INIS)

    El-Zahhar, A.A.; Abdel-Aziz, H.M.; Siyam, T.

    2005-01-01

    Poly(acrylamide-acrylic acid). ethylenediamine tetra acetic acid disodium salt P(AM-AA). EDTANa2, Poly(acrylamide-acrylic acid)montmorillonite P(AM-AA). montmorillonite, and Poly(acrylamide acrylic acid)-potassium nickel hexacyanoferrate P(AM-AA)-KNiHCF were prepared by gamma radiation- induced template polymerization of (AA) on P(AM) as a template polymer in the presence of EDTANa2, Clay(montmorillonite), KNiHCF and KZnHCF, respectively. The capacity of the prepared P (AM-AA)-EDTANa2 and P (AM-AA)-montmorillonite composites increases with increasing of EDTANa2 and montmorillonite concentration then decreases. While the capacity of P(AM- AA). KNiHCF composites increases with increasing of KNiHCF content. The characteristic properties of prepared polymeric composites resins were studied by using FTIR spectroscopy

  16. The Effect of Titanium Tetrafluoride and Sodium Hypochlorite on the Shear Bond Strength of Methacrylate and Silorane Based Composite Resins: an In-Vitro Study.

    Science.gov (United States)

    Sharafeddin, Farahnaz; Koohpeima, Fatemeh; Razazan, Nader

    2017-06-01

    The bond strength of composites with different adhesive systems with dentin is an important factor in long term durability of composite restorations. The effect of titanium tetrafluoride (TiF 4 ) as anti caries agent and sodium hypochlorite (NaOCl) as disinfectant on the shear bond of nanofilled and silorane based composite resins have not been investigated in previous studies. This study was conducted to determine bond strength between dentin and two composite systems, by means of shear bond test using TiF 4 and NaOCl. Middle dentin of 60 intact extracted maxillary premolar teeth were exposed by sectioning the crowns at a depth of 2mm from central groove and parallel to the occlusal surface. Standardized smear layer was created using a 600-grit silicon carbide paper and then samples were embedded in acrylic resin blocks. Then the samples were randomly divided into 6 \\groups summarized as Group I: Z350, Group II: Z350+ NaOCl, Group III: Z350+ TiF 4 , Group IV: P90, Group V: P90+ NaOCl, Group VI: P90+ TiF 4 according to manufacturer's instruction. Then samples were subjected to shear bond strength (SBS) test using universal testing machine and data were analyzed using ANOVA and Tukey tests ( p composite resin ( p = 0.004), and also silorane based composite resin ( p = 0.006). Application of 4% TiF 4 caused a significant increase in SBS of silorane based composite resin ( p = 0.001). The effect of TiF 4 on nanofilled composite was not statistically significant. Using TiF 4 has a positive effect on increasing the shear bond while NaOCl has negative effect on bond strength.

  17. Effect of adhesive luting on the fracture resistance of zirconia compared to that of composite resin and lithium disilicate glass ceramic

    Directory of Open Access Journals (Sweden)

    Myung-Jin Lim

    2017-02-01

    Full Text Available Objectives The purpose of this study was to evaluate the effect of adhesive luting on the fracture resistance of zirconia compared to that of a composite resin and a lithium disilicate glass ceramic. Materials and Methods The specimens (dimension: 2 mm × 2 mm × 25 mm of the composite resin, lithium disilicate glass ceramic, and yttria-stabilized tetragonal zirconia polycrystal (Y-TZP were prepared. These were then divided into nine groups: three non-luting groups, three non-adhesive luting groups, and three adhesive luting groups, for each restorative material. In the non-luting groups, specimens were placed on the bovine tooth without any luting agents. In the non-adhesive luting groups, only zinc phosphate cement was used for luting the specimen to the bovine tooth. In the adhesive luting groups, specimens were pretreated, and the adhesive luting procedure was performed using a self-adhesive resin cement. For all the groups, a flexural test was performed using universal testing machine, in which the fracture resistance was measured by recording the force at which the specimen was fractured. Results The fracture resistance after adhesive luting increased by approximately 29% in the case of the composite resin, 26% in the case of the lithium disilicate glass ceramic, and only 2% in the case of Y-TZP as compared to non-adhesive luting. Conclusions The fracture resistance of Y-TZP did not increased significantly after adhesive luting as compared to that of the composite resin and the lithium disilicate glass ceramic.

  18. Resin Systems and Chemistry-Degradation Mechanisms and Durability in Long-Term Durability of Polymeric Matrix Composites. Chapter 1

    Science.gov (United States)

    Hinkley, Jeffrey A.; Connell, John W.

    2012-01-01

    In choosing a polymer-matrix composite material for a particular application, a number of factors need to be weighed. Among these are mechanical requirements, fabrication method (e.g. press-molding, resin infusion, filament winding, tape layup), and use conditions. Primary among the environmental exposures encountered in aerospace structures are moisture and elevated temperatures, but certain applications may require resistance to other fluids and solvents, alkaline agents, thermal cycling, radiation, or rapid, localized heating (for example, lightning strike). In this chapter, the main classes of polymer resin systems found in aerospace composites will be discussed. Within each class, their responses to environmental factors and the associated degradation mechanisms will be reviewed.

  19. Effects of Wet and Dry Finishing and Polishing on Surface Roughness and Microhardness of Composite Resins

    Science.gov (United States)

    Nasoohi, Negin; Hoorizad, Maryam

    2017-01-01

    Objectives: This study aimed to assess the effect of wet and dry finishing and polishing on microhardness and roughness of microhybrid and nanohybrid composites. Materials and Methods: Thirty samples were fabricated of each of the Polofil Supra and Aelite Aesthetic All-Purpose Body microhybrid and Grandio and Aelite Aesthetic Enamel nanohybrid composite resins. Each group (n=30) was divided into three subgroups of D, W and C (n=10). Finishing and polishing were performed dry in group D and under water coolant in group W. Group C served as the control group and did not receive finishing and polishing. Surface roughness of samples was measured by a profilometer and their hardness was measured by a Vickers hardness tester. Data were analyzed using two-way ANOVA (Pcomposites (Pcomposites (Pcomposites (Pcomposite resins. PMID:29104597

  20. A randomized controlled three year evaluation of "bulk-filled" posterior resin restorations based on stress decreasing resin technology

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2014-01-01

    -hybrid resin composite (Ceram X mono) layer. In the second cavity, the hybrid resin composite was placed in 2mm increments. The restorations were evaluated using slightly modified USPHS criteria at baseline and then yearly during 3 years. Caries risk and parafunctional habits of the participants were estimated...

  1. Tensile bond strength of resin composite repair in vitro using different surface preparation conditionings to an aged CAD/CAM resin nanoceramic.

    Science.gov (United States)

    Stawarczyk, Bogna; Krawczuk, Andreas; Ilie, Nicoleta

    2015-03-01

    This study was conducted in order to assess the pretreatment method (air abrasion, both wet and dry, and Al2O3 grinder), the conditioning method (comprised of different adhesive systems), the repair resin composite (low and high modulus of elasticity), the contamination of CoJet air-abraded surfaces with water, and the effect phosphoric acid on the macrotensile bond strength (TBS) to aged CAD/CAM resin nanoceramic (RNC). Aged RNC substrates (LAVA Ultimate, 3M ESPE; N = 900; 10,000 cycles, 5 °C/55 °C) were air-abraded (CoJet 3M ESPE) with and without water contamination or treated with an Al2O3 grinder (Cimara, Voco). Immediately after pretreatment, half of the specimens were additionally cleaned with phosphoric acid, while the rest were only rinsed with water. Four intermediate agents (Futurabond U/VOCO, Scotchbond Universal/3M ESPE, One Coat Bond/Coltène Whaledent, visio.link/bredent) were selected for conditioning the surface, while no conditioned specimens acted as control groups. Specimens were thereafter repaired using two direct resin composites (Arabesk Top and GrandioSo, VOCO), stored for 24 h at 37 °C in H2O, and thermally aged for 10,000 cycles (5 °C/55 °C; n = 15/subgroup). TBS and failure types were determined and evaluated with four- and one-way ANOVA and χ (2) test (p universal adhesives proved to be effective intermediate agents for repairing aged CAD/CAM RNC, while visio.link and Scotchbond Universal performed slightly better than Futurabond U. Phosphoric acid or water contamination of the air-abraded surface does not affect the repair bond strength.

  2. Microtensile Bond Strength of New Ceramic/Polymer Materials Repaired with Composite Resin

    Science.gov (United States)

    2015-06-30

    also have been shown to have higher enamel wear rates than composite-resin CAD/CAM restorations (Mӧrmann et al, 2013). As material choices, cost, and...although the longevity of these repairs has not been validated by clinical studies. Paradigm MZ100 showed the least amount of opposing enamel wear...ability to absorb shock, resist staining and stop crack propagation. Further manufacturer claims are that ceramic/polymer materials are easily

  3. The Effect of Resin-modified Glass-ionomer Cement Base and Bulk-fill Resin Composite on Cuspal Deformation.

    Science.gov (United States)

    Nguyen, K V; Wong, R H; Palamara, J; Burrow, M F

    2016-01-01

    This study investigated cuspal deformation in teeth restored with different types of adhesive materials with and without a base. Mesio-occluso-distal slot cavities of moderately large dimension were prepared on extracted maxillary premolars (n=24). Teeth were assigned to one of four groups and restored with either a sonic-activated bulk-fill resin composite (RC) (SonicFill), or a conventional nanohybrid RC (Herculite Ultra). The base materials used were a flowable nanofilled RC (Premise Flowable) and a high-viscosity resin-modified glass-ionomer cement (RMGIC) (Riva Light-Cure HV). Cuspal deflection was measured with two direct current differential transformers, each contacting a buccal and palatal cusp. Cuspal movements were recorded during and after restoration placement. Data for the buccal and palatal cusp deflections were combined to give the net cuspal deflection. Data varied widely. All teeth experienced net inward cuspal movement. No statistically significant differences in cuspal deflection were found among the four test groups. The use of a flowable RC or an RMGIC in closed-laminate restorations produced the same degree of cuspal movement as restorations filled with only a conventional nanohybrid or bulk-fill RC.

  4. Durability of a low shrinkage TEGDMA/HEMA-free resin composite system in Class II restorations

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2017-01-01

    with a mean age of 53 years (range 29-82). Each participant received at random two, as similar as possible, Class II restorations. In the first cavity of each pair the TEGDMA/HEMA-free resin composite system was placed with its 3-step etch-and-rinse adhesive (cmf-els). In the second cavity a 1-step HEMA......Objective: The objective of this randomized controlled prospective trial was to evaluate the durability of a low shrinkage and TEGDMA/HEMA-free resin composite system in posterior restorations in a 6-year follow up. Material and methods: 139 Class II restorations were placed in 67 patients......-free self-etch adhesive was used (AdheSe One F). The restorations were evaluated using slightly modified USPHS criteria at baseline and then yearly during 6 years. Caries risk and parafunctional habits of the participants were estimated. Results: Three molar teeth showed mild post-operative sensitivity...

  5. Short communication: pre- and co-curing effect of adhesives on shear bond strengths of composite resins to primary enamel and dentine: an in vitro study.

    Science.gov (United States)

    Viswanathan, R; Shashibhushan, K K; Subba Reddy, V V

    2011-12-01

    To evaluate and compare shear bond strengths of composite resins to primary enamel and dentine when the adhesives are pre-cured (light cured before the application of the resin) or co-cured (adhesive and the resin light cured together). Buccal surfaces of 80 caries-free primary molars were wet ground to create bonding surfaces on enamel and dentine and specimens mounted on acrylic blocks. Two bonding agents (Prime and Bond NT® and Xeno III®) were applied to either enamel or dentine as per manufacturer's instructions. In 40 specimens, the bonding agent was light cured immediately after the application (pre-cured). The other 40 specimens were not light cured until the composite resin application (co-cured). Resin composite cylinders were made incrementally using acrylic moulds over the adhesives and light cured. Specimens were stored in deionised water for 24 hours at room temperature. Shear bond strength was measured using an Instron universal testing machine (in MPa) and was analysed with Student's unpaired t test. Light curing the adhesive separately produced significantly higher bond strengths to primary dentine than co-curing (padhesive separately did not produce significantly different bond strengths to primary enamel (p>0.05). Curing sequence had no significant effect on shear bond strength of adhesives on the primary enamel. Pre-curing adhesives before curing composite resins produced greater shear bond strength to primary dentine.

  6. Influence of polishing on surface roughness following toothbrushing wear of composite resins.

    Science.gov (United States)

    Dalla-Vecchia, Karine Battestin; Taborda, Talita Damas; Stona, Deborah; Pressi, Heloísa; Burnett Júnior, Luiz Henrique; Rodrigues-Junior, Sinval Adalberto

    2017-01-01

    This study aimed to evaluate the influence of different polishing systems on the surface roughness of composite resins following procedures to simulate the effects of toothbrushing over time. Four currently available commercial composites were used to make 128 cylindrical specimens. The specimens were randomly allocated to polishing with a 1-step polisher or 1 of 3 multistep polishers (n = 8 per group). The baseline surface roughness was measured, and the specimens were submitted to 5000, 10,000, and 20,000 brushing cycles to represent toothbrushing throughout 6, 12, and 24 months, respectively. Results showed that surface roughness was influenced by the type of composite and polishing system and was not influenced by the simulated toothbrushing time. However, the surface roughness, as challenged by toothbrushing wear, was affected by the interaction among the composite, the polisher, and the toothbrushing time. The 1-step polisher produced the highest surface roughness and influenced toothbrushing wear resistance of some composites.

  7. Repair bond strength of composite resin to sandblasted and laser irradiated Y-TZP ceramic surfaces.

    Science.gov (United States)

    Kirmali, Omer; Barutcigil, Çağatay; Ozarslan, Mehmet Mustafa; Barutcigil, Kubilay; Harorlı, Osman Tolga

    2015-01-01

    This study investigated the effects of different surface treatments on the repair bond strength of yttrium-stabilized tetragonal zirconia polycrystalline ceramic (Y-TZP) zirconia to a composite resin. Sixty Y-TZP zirconia specimens were prepared and randomly divided into six groups (n = 10) as follows: Group 1, surface grinding with Cimara grinding bur (control); Group 2, sandblasted with 30 µm silica-coated alumina particles; Group 3, Nd:YAG laser irradiation; Group 4, Er,Cr:YSGG laser irradiation; Group 5, sandblasted + Nd:YAG laser irradiation; and Group 6, sandblasted + Er,Cr:YSGG laser irradiation. After surface treatments, the Cimara(®) System was selected for the repair method and applied to all specimens. A composite resin was built-up on each zirconia surface using a cylindrical mold (5 × 3 mm) and incrementally filled. The repair bond strength was measured with a universal test machine. Data were analyzed using a one-way ANOVA and a Tukey HSD test (p = 0.05). Surface topography after treatments were evaluated by a scanning electron microscope (SEM). Shear bond strength mean values ranged from 15.896 to 18.875 MPa. There was a statistically significant difference between group 3 and the control group (p < 0.05). Also, a significant increase in bond strength values was noted in group 6 (p < 0.05). All surface treatment methods enhanced the repair bond strength of the composite to zirconia; however, there were no significant differences between treatment methods. The results revealed that Nd:YAG laser irradiation along with the combination of sandblasting and Er,Cr:YSGG laser irradiation provided a significant increase in bond strength between the zirconia and composite resin. © Wiley Periodicals, Inc.

  8. The effect of two in-office and home bleaching gels on microhardness of composite resin

    Directory of Open Access Journals (Sweden)

    Alizadeh Oskoee P.

    2007-07-01

    Full Text Available Background and Aim: Bleaching products as chemical materials can exert side effects on soft and hard tissues and existing restorative materials with oxidizing mechanism. The aim of this study was to evaluate the effect of 15% and 35% carbamide peroxide gels as home and in-office bleaching agents respectively, on microhardness and surface topography of composite resin.Materials and Methods: In this in vitro study, a total of 75 disc shaped specimens were prepared from Z100  composite resin (3M and randomly divided into three groups with following treatment designs: group 1, 370C distilled water, group 2, 15% carbamide peroxide, 6 hours/day for 3 weeks, group 3, 35% carbamide peroxide 30 minutes/week for 3 weeks. The microhardness (Vickers hardness of samples was measured using Shimadzu set on three different points of each sample. 8 samples of each group were selected randomly to be assessed by scanning electron microscopy (SEM for probable changes in surface topography. Data were analyzed using one way ANOVA and Duncan tests with p<0.05 as the level of significance. Results: 15% carbamide peroxide group had the maximum amount of microhardness (84.59±1.87 and 35% carbamide peroxide group had the minimum (76. 14±1.77. Only the difference between home bleaching and control group was not statistically significant (P=0.24. The SEM assessing revealed no changes in surface topography.Conclusion: Based on the results of this study, in-office bleaching may decrease the microhardness of composite resin.

  9. Repair Bond Strength of Aged Resin Composite after Different Surface and Bonding Treatments

    Directory of Open Access Journals (Sweden)

    Michael Wendler

    2016-07-01

    Full Text Available The aim of this study was to compare the effect of different mechanical surface treatments and chemical bonding protocols on the tensile bond strength (TBS of aged composite. Bar specimens were produced using a nanohybrid resin composite and aged in distilled water for 30 days. Different surface treatments (diamond bur, phosphoric acid, silane, and sandblasting with Al2O3 or CoJet Sand, as well as bonding protocols (Primer/Adhesive were used prior to application of the repair composite. TBS of the specimens was measured and the results were analyzed using analysis of variance (ANOVA and the Student–Newman–Keuls test (α = 0.05. Mechanically treated surfaces were characterized under SEM and by profilometry. The effect of water aging on the degree of conversion was measured by means of FTIR-ATR spectroscopy. An important increase in the degree of conversion was observed after aging. No significant differences in TBS were observed among the mechanical surface treatments, despite variations in surface roughness profiles. Phosphoric acid etching significantly improved repair bond strength values. The cohesive TBS of the material was only reached using resin bonding agents. Application of an intermediate bonding system plays a key role in achieving reliable repair bond strengths, whereas the kind of mechanical surface treatment appears to play a secondary role.

  10. A study on the radiopacity of cavity lining materials for posterior composite resin restoration

    International Nuclear Information System (INIS)

    Moon, Joo Hoon; Choi, Eui Hwan

    2000-01-01

    The aim of this study was to determine the relative radiopacities of cavity lining materials (Resin-modified Glass Ionomer cement, Compomer and Flowable resin) for posterior composite resin restoration. Resin-modified glass ionomer cement (Fuji II LC, Vitrebond (TM)), Compomers (Dyract , Compoglass, F2000, Dyract(R) flow Compoglass Flow) and Flowable resins (Tetric (R) flow, Aeliteflo (TM) Revolution (TM)) were used. Five specimens of 5 mm in diameter and 2 mm thick were fabricated with each material. Human molars were horizontally sectioned 2 mm thick to include both enamel and dentin. The radiopacities of enamel, dentin, cavity lining materials, aluminum step wedge were obtained from conventional radiograph and NIH image program. All the tested lining materials showed levels of radiopacity the same as or greater than that of dentin. All compomer tested (Dyract (R), Compoglass, F2000, Dyract (R) flow, Compoglass Flow) and Vitrebond (TM), Tetric (R) flow were more radiopaque than enamel. The radiopacities of Fuji II LC and Revolution (TM) were between enamel and dentin and resin-modified glass ionomer cement, Compomer and Tetric (R) flow were greater than those of Revolution (TM), Aeliteflo (TM) or dentin. The level of radiopacity of the tested materials was variable; those with low radiopacity should be avoided in class II restorations, where a clear determination of recurrent caries by the examining clinician could be compromised. Clinician should be able to distinguish these cavity lining materials radiographically from recurrent decay, voids, gaps, or other defects that lead to clinical failure. Utilization of materials ranked more radiopaque than enamel would enable clinicians to distinguish the lining material from tooth structure.

  11. A study on the radiopacity of cavity lining materials for posterior composite resin restoration

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Joo Hoon [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chosun University, Kwangju (Korea, Republic of); Choi, Eui Hwan [Dept. of Conservative Dentistry, College of Dentistry, Chosun University, Kwangju (Korea, Republic of)

    2000-12-15

    The aim of this study was to determine the relative radiopacities of cavity lining materials (Resin-modified Glass Ionomer cement, Compomer and Flowable resin) for posterior composite resin restoration. Resin-modified glass ionomer cement (Fuji II LC, Vitrebond (TM)), Compomers (Dyract , Compoglass, F2000, Dyract(R) flow Compoglass Flow) and Flowable resins (Tetric (R) flow, Aeliteflo (TM) Revolution (TM)) were used. Five specimens of 5 mm in diameter and 2 mm thick were fabricated with each material. Human molars were horizontally sectioned 2 mm thick to include both enamel and dentin. The radiopacities of enamel, dentin, cavity lining materials, aluminum step wedge were obtained from conventional radiograph and NIH image program. All the tested lining materials showed levels of radiopacity the same as or greater than that of dentin. All compomer tested (Dyract (R), Compoglass, F2000, Dyract (R) flow, Compoglass Flow) and Vitrebond (TM), Tetric (R) flow were more radiopaque than enamel. The radiopacities of Fuji II LC and Revolution (TM) were between enamel and dentin and resin-modified glass ionomer cement, Compomer and Tetric (R) flow were greater than those of Revolution (TM), Aeliteflo (TM) or dentin. The level of radiopacity of the tested materials was variable; those with low radiopacity should be avoided in class II restorations, where a clear determination of recurrent caries by the examining clinician could be compromised. Clinician should be able to distinguish these cavity lining materials radiographically from recurrent decay, voids, gaps, or other defects that lead to clinical failure. Utilization of materials ranked more radiopaque than enamel would enable clinicians to distinguish the lining material from tooth structure.

  12. Adhesion of resin composite core materials to dentin.

    Science.gov (United States)

    O'Keefe, K L; Powers, J M

    2001-01-01

    This study determined (1) the effect of polymerization mode of resin composite core materials and dental adhesives on the bond strength to dentin, and (2) if dental adhesives perform as well to dentin etched with phosphoric acid as to dentin etched with self-etching primer. Human third molars were sectioned 2 mm from the highest pulp horn and polished. Three core materials (Fluorocore [dual cured], Core Paste [self-cured], and Clearfil Photo Core [light cured]) and two adhesives (Prime & Bond NT Dual Cure and Clearfil SE Bond [light cured]) were bonded to dentin using two dentin etching conditions. After storage, specimens were debonded in microtension and bond strengths were calculated. Scanning electron micrographs of representative bonding interfaces were analyzed. Analysis showed differences among core materials, adhesives, and etching conditions. Among core materials, dual-cured Fluorocore had the highest bond strengths. There were incompatibilities between self-cured Core Paste and Prime & Bond NT in both etched (0 MPa) and nonetched (3.0 MPa) dentin. Among adhesives, in most cases Clearfil SE Bond had higher bond strengths than Prime & Bond NT and bond strengths were higher to self-etched than to phosphoric acid-etched dentin. Scanning electron micrographs did not show a relationship between resin tags and bond strengths. There were incompatibilities between a self-cured core material and a dual-cured adhesive. All other combinations of core materials and adhesives produced strong in vitro bond strengths both in the self-etched and phosphoric acid-etched conditions.

  13. Do Dental Resin Composites Accumulate More Oral Biofilms and Plaque than Amalgam and Glass Ionomer Materials?

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2016-11-01

    Full Text Available A long-time drawback of dental composites is that they accumulate more biofilms and plaques than amalgam and glass ionomer restorative materials. It would be highly desirable to develop a new composite with reduced biofilm growth, while avoiding the non-esthetics of amalgam and low strength of glass ionomer. The objectives of this study were to: (1 develop a protein-repellent composite with reduced biofilms matching amalgam and glass ionomer for the first time; and (2 investigate their protein adsorption, biofilms, and mechanical properties. Five materials were tested: A new composite containing 3% of protein-repellent 2-methacryloyloxyethyl phosphorylcholine (MPC; the composite with 0% MPC as control; commercial composite control; dental amalgam; resin-modified glass ionomer (RMGI. A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate metabolic activity, colony-forming units (CFU, and lactic acid production. Composite with 3% MPC had flexural strength similar to those with 0% MPC and commercial composite control (p > 0.1, and much greater than RMGI (p < 0.05. Composite with 3% MPC had protein adsorption that was only 1/10 that of control composites (p < 0.05. Composite with 3% MPC had biofilm CFU and lactic acid much lower than control composites (p < 0.05. Biofilm growth, metabolic activity and lactic acid on the new composite with 3% MPC were reduced to the low level of amalgam and RMGI (p > 0.1. In conclusion, a new protein-repellent dental resin composite reduced oral biofilm growth and acid production to the low levels of non-esthetic amalgam and RMGI for the first time. The long-held conclusion that dental composites accumulate more biofilms than amalgam and glass ionomer is no longer true. The novel composite is promising to finally overcome the major biofilm-accumulation drawback of dental composites in order to reduce biofilm acids and secondary caries.

  14. Fabrication and characterization of high impact hybrid matrix composites from thermoset resin and dyneema-glass fabric reinforcement

    Science.gov (United States)

    Patel, R. H.; Sharma, S.; Pansuriya, T.; Malgani, E. V.; Sevkani, V.

    2018-05-01

    Hybrid composites have been fabricated by hand lay-up technique with epoxy resin and diethylene tri amine as a hardener for high impact energy absorption with sandwich stacking of different reinforcements of dyneema and glass fabric. High impact grade composites are nowadays gaining a lot of importance in the field of high mechanical load bearing applications, ballistics and bulletproofing. The present work emphases on the fabrication and mechanical properties of the hybrid composites of cut resistant dyneema fabric along with glass fabric reinforced in the thermosetting resin. i.e. epoxy. The prime importance while fabricating such materials have been given to the processing along with selection of the raw materials. High impact resistive materials with low density and henceforth low weight have been manufactured and characterized by IZOD impact tester, UTM, Archimedes density meter and SEM. Throughout the work, satisfactory results have been obtained. Impact resistance was observed to be boosted three times as that of the reference sample of glass fabric and epoxy. The density of the hybrid composite is observed to be 25% as that of the reference sample.

  15. Analysis of long-term monomer elution from bulk-fill and conventional resin-composites using high performance liquid chromatography.

    Science.gov (United States)

    Alshali, Ruwaida Z; Salim, Nesreen A; Sung, Rehana; Satterthwaite, Julian D; Silikas, Nick

    2015-12-01

    The aim of this study was to assess monomer elution from bulk-fill and conventional resin-composites stored in different media using high performance liquid chromatography (HPLC) for up to 3 months. Six bulk-fill (SureFil SDR, Venus Bulk Fill, X-tra base, Filtek Bulk Fill flowable, Sonic Fill, and Tetric EvoCeram Bulk Fill) and eight conventional resin-composites (Grandioso Flow, Venus Diamond Flow, X-Flow, Filtek Supreme XTE, Grandioso, Venus Diamond, TPH Spectrum, and Filtek Z250) were tested. Cylindrical samples (n=5) were immersed in water, 70% ethanol/water solution (70% E/W), and artificial saliva and stored at 37°C for 24h, 1 month, and 3 months. The storage solutions were analysed with HPLC. Data were analysed with repeated measures ANOVA, one-way ANOVA, and Tukey post hoc test at α=0.05. Monomers detected in water and artificial saliva were TEGDMA, DEGDMA, UDMA, and TCD-DI-HEA. No eluted monomers were detected from X-tra base and Sonic fill in these media. All monomers showed a variable extent of elution into 70% E/W with significantly higher amounts than those detected in water and artificial saliva. Significantly higher elution was detected from UDMA-BisEMA based composites compared to BisGMA and BisGMA-BisEMA based systems in 70% E/W. The rate of elution into different media varied between different monomers and was highly dependent on the molecular weight of the eluted compounds. Elution from bulk-fill resin-composites is comparable to that of conventional materials despite their increased increment thickness. Monomer elution is highly dependent on the hydrophobicity of the base monomers and the final network characteristics of the resin-matrix. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  16. The effect of bulk-resin CNT-enrichment on damage and plasticity in shear-loaded laminated composites

    KAUST Repository

    Ventura, Isaac Aguilar; Lubineau, Gilles

    2013-01-01

    One way to improve multi functionality of epoxy-based laminated composites is to dope the resin with carbon nanotubes. Many investigators have focused on the elastic and fracture behavior of such nano-modified polymers under tensile loading. Yet

  17. Survival rates against fracture of endodontically treated posterior teeth restored with full-coverage crowns or resin composite restorations: a systematic review

    Directory of Open Access Journals (Sweden)

    Warattama Suksaphar

    2017-07-01

    Full Text Available This systematic review aims to summarize the current clinical studies that investigated survival rates against fracture of endodontically treated posterior teeth restored with crowns or resin composite restorations. Literature search were performed using keywords. Publications from 1980 to 2016 were searched in PubMed, ScienceDirect, Web of Science, MEDLINE, and SCOPUS. Included studies were selected based on inclusion and exclusion criteria. Three clinical studies were included: 1 randomized controlled trial and 1 prospective and 1 retrospective cohort studies. Pooled survival rates ranged from 94%–100% and 91.9%–100% for crowns and resin composite, respectively. The majority of teeth had no more than 3 surface loss of tooth structure. The studies included were heterogeneous, and were not appropriate for further meta-analysis. Current evidence suggested that the survival rates against the fracture of endodontically treated posterior teeth restored with crowns or resin composites were not significantly different in the teeth with minimum to moderate loss of tooth structure.

  18. Microshear bond strength of resin composite to teeth affected by molar hypomineralization using 2 adhesive systems.

    Science.gov (United States)

    William, Vanessa; Burrow, Michael F; Palamara, Joseph E A; Messer, Louise B

    2006-01-01

    When restoring hypomineralized first permanent molars, placement of cavo-surface margins can be difficult to ascertain due to uncertainty of the bonding capability of the tooth surface. The purpose of this study was to investigate the adhesion of resin composite bonded to control and hypomineralized enamel with an all-etch single-bottle adhesive or self-etching primer adhesive. Specimens of control enamel (N=44) and hypomineralized enamel (N=45) had a 0.975-mm diameter composite rod (Filtek Supreme Universal Restorative) bonded with either 3M ESPE Single Bond or Clearfil SE Bond following manufacturers' instructions. Specimens were stressed in shear at 1 mm/min to failure (microshear bond strength). Etched enamel surfaces and enamel-adhesive interfaces were examined under scanning electron microscopy. The microshear bond strength (MPa) of resin composite bonded to hypomineralized enamel was significantly lower than for control enamel (3M ESPE Single Bond=7.08 +/- 4.90 vs 16.27 +/- 10.04; Clearfil SE Bond=10.39 +/- 7.56 vs 19.63 +/- 7.42; P=.001). Fractures were predominantly adhesive in control enamel and cohesive in hypomineralized enamel. Scotchbond etchant produced deep interprismatic and intercrystal porosity in control enamel and shallow etch patterns with minimal intercrystal porosity in hypomineralized enamel. Control enamel appeared almost unaffected by SE Primer; hypomineralized enamel showed shallow etching. The hypomineralized enamel-adhesive interface was porous with cracks in the enamel. The control enamel-adhesive interface displayed a hybrid layer of even thickness. The microshear bond strength of resin composite bonded to hypomineralized enamel was significantly lower than for control enamel. This was supported by differences seen in etch patterns and at the enamel-adhesive interface.

  19. Effect of resin chemistry on depth of cure and cytotoxicity of dental resin composites

    International Nuclear Information System (INIS)

    Susila Anand, V.; Balasubramanian, Venkatesh

    2014-01-01

    Highlights: • Dental composites have differences in polymerization within 2 mm thickness. • Degree of conversion alone may not affect the biocompatibility of composite. • Unreacted double bonds in dental composites may influence biocompatibility. • Magnitude of double bonds depends on the polymerization and chemical composition. • These influence biocompatibility especially if they possess lipophylic properties. -- Abstract: New dental composite restorative materials are being introduced aiming to overcome the disadvantages of contemporary materials. Hence there is a need to analyze the critical properties of these composites to aid in clinical application. This study aims to comparatively analyze the degree of conversion (DC), residual reactivity (DBC/reactivity) and cytotoxicity of 2 composites based on different resin chemistry. Ceram X and Filtek P90 were used in the study to prepare disc shaped samples of 2 mm thickness and 4 mm diameter. The samples for cytotoxicity were cured for 40 s and those of Fourier Transform Infra-red Spectroscopy (FTIR) (DBC/reactivity and DC) for 5 s, 10 s, 20 s and 40 s, at an average intensity of 800 mW/cm 2 with Quartz–Tungsten–Halogen (QTH) light. DC was calculated in 60–100 μm thick and 6 mm diameter samples. Double bonds concentration/reactivity was measured in approximately 80 μm thick sections prepared from the 2 mm thick discs using a hard tissue microtome. The cell viability was scored by Trypan blue exclusion staining technique at 24 h and 48 h. Both composites showed a progressive increase in double bonds/reactivity as the distance from curing probe increased which was inversely proportional to the curing time. The DC of Filtek P90 was 20% and 96% and that of Ceram X 33% and 50% at 5 s and 40 s, respectively. Ceram X showed statistically significantly higher cell viability score at both 24 h and 48 h than Filtek P90. The results were statistically analyzed using non-parametric Kruskal–Wallis, Mann

  20. Effect of resin chemistry on depth of cure and cytotoxicity of dental resin composites

    Energy Technology Data Exchange (ETDEWEB)

    Susila Anand, V. [Rehabilitation Bioengineering Group, Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036 (India); Department of Conservative Dentistry and Endodontics, Saveetha Dental College, Saveetha University, Chennai 600077 (India); Balasubramanian, Venkatesh, E-mail: chanakya@iitm.ac.in [Rehabilitation Bioengineering Group, Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036 (India)

    2014-02-15

    Highlights: • Dental composites have differences in polymerization within 2 mm thickness. • Degree of conversion alone may not affect the biocompatibility of composite. • Unreacted double bonds in dental composites may influence biocompatibility. • Magnitude of double bonds depends on the polymerization and chemical composition. • These influence biocompatibility especially if they possess lipophylic properties. -- Abstract: New dental composite restorative materials are being introduced aiming to overcome the disadvantages of contemporary materials. Hence there is a need to analyze the critical properties of these composites to aid in clinical application. This study aims to comparatively analyze the degree of conversion (DC), residual reactivity (DBC/reactivity) and cytotoxicity of 2 composites based on different resin chemistry. Ceram X and Filtek P90 were used in the study to prepare disc shaped samples of 2 mm thickness and 4 mm diameter. The samples for cytotoxicity were cured for 40 s and those of Fourier Transform Infra-red Spectroscopy (FTIR) (DBC/reactivity and DC) for 5 s, 10 s, 20 s and 40 s, at an average intensity of 800 mW/cm{sup 2} with Quartz–Tungsten–Halogen (QTH) light. DC was calculated in 60–100 μm thick and 6 mm diameter samples. Double bonds concentration/reactivity was measured in approximately 80 μm thick sections prepared from the 2 mm thick discs using a hard tissue microtome. The cell viability was scored by Trypan blue exclusion staining technique at 24 h and 48 h. Both composites showed a progressive increase in double bonds/reactivity as the distance from curing probe increased which was inversely proportional to the curing time. The DC of Filtek P90 was 20% and 96% and that of Ceram X 33% and 50% at 5 s and 40 s, respectively. Ceram X showed statistically significantly higher cell viability score at both 24 h and 48 h than Filtek P90. The results were statistically analyzed using non-parametric Kruskal