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Sample records for light-cured composite resins

  1. Effects of light curing method and resin composite composition on composite adaptation to the cavity wall.

    Science.gov (United States)

    Yoshikawa, Takako; Morigami, Makoto; Sadr, Alireza; Tagami, Junji

    2014-01-01

    This study aimed to evaluate the effects of the light curing method and resin composite composition on marginal sealing and resin composite adaptation to the cavity wall. Cylindrical cavities were prepared on the buccal or lingual cervical regions. The teeth were restored using Clearfil Liner Bond 2V adhesive system and filled with Clearfil Photo Bright or Palfique Estelite resin composite. The resins were cured using the conventional or slow-start light curing method. After thermal cycling, the specimens were subjected to a dye penetration test. The slow-start curing method showed better resin composite adaptation to the cavity wall for both composites. Furthermore, the slow-start curing method resulted in significantly improved dentin marginal sealing compared with the conventional method for Clearfil Photo Bright. The light-cured resin composite, which exhibited increased contrast ratios duringpolymerization, seems to suggest high compensation for polymerization contraction stress when using the slow-start curing method.

  2. 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

  3. 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

  4. Changes in the temperature of a dental light-cured composite resin by different light-curing units

    Science.gov (United States)

    Rastelli, A. N. S.; Jacomassi, D. P.; Bagnato, V. S.

    2008-08-01

    The purpose of this study was to evaluate the temperature increase during the polymerization process through the use of three different light-curing units with different irradiation times. One argon laser (Innova, Coherent), one halogen (Optilight 501, Demetron), and one blue LED (LEC 1000, MM Optics) LCU with 500 mW/cm2 during 5, 10, 20, 30, 40, 50, and 60 s of irradiation times were used in this study. The composite resin used was a microhybrid Filtek Z-250 (3M/ESPE) at color A2. The samples were made in a metallic mold 2 mm in thickness and 4 mm in diameter and previously light-cured during 40 s. A thermocouple (Model 120 202 EAJ, Fenwal Electronic, Milford, MA, USA) was introduced in the composite resin to measure the temperature increase during the curing process. The highest temperature increase was recorded with a Curing Light 2500 halogen LCU (5 and 31°C after 5 and 60 s, respectively), while the lowest temperature increase was recorded for the Innova LCU based on an argon laser (2 and 11°C after 5 and 60 s, respectively). The temperature recorded for LCU based on a blue LED was 3 and 22°C after 5 and 60 s, respectively. There was a quantifiable amount of heat generated during the visible light curing of a composite resin. The amount of heat generated was influenced by the characteristics of the light-curing units used and the irradiation times.

  5. An investigation on the effect of light cure and self cure composite resins on bonding strength of light cure glass ionomer to dentin (In-vitro

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    Pahlavan A

    2004-02-01

    Full Text Available Composite reins have recently become popular for posterior teeth restorations. Gap"nformation and subsequent microleakage are of the complications resulting from such restorations. One of the"ntechniques to overcome polymerization shrinkage of composite resins is sandwich technique (application of"nglass ionomer as a base beneath the composite resin. Since polymerization patterns in two types of composite"nresins (light cure and self cure differ from each other, various effects on the bond strength between glass"nionomer and dentin are expected."nPurpose: The aim of this in vitro study was to evaluate the effects of self- cure and light- cure composite"nresins in sandwich technique on the bond strength of light cure glass ionomer and dentin."nMaterials and Methods: 40 extracted human premolars were selected and divided into four groups:"nGroup 1: Light cure glass ionomer of 1mm thickness was placed on dentin."nGroup 2: 1mm thickness of light cure glass ionomer plus a mass of self cure composite resin of 2mm"nthickness were placed."nGroup 3: 1mm thickness of light cure glass ionomer plus light cure composite resin as two separate 1mm layer"nwere placed."nGroup 4: 1mm thickness of light cure glass ionomer with 37% phosphoric acid etching followed by two"nseparate layers of light cure composite resin of 1 mm thickness were placed."nSEM was used to determine gap size ai Gl- dentin and Gi- composite interlaces. The findings were analyzed"nby ANOVA and t-student tests."nResults: Groups 1 and 2 showed no gap at Gl-dentm interface and also cracks were not observed in all these"nspecimens. In group 3, there was gap between light cure GI and light cure composite resin and cracks were"nseen in GI, too. Group 4 showed gap at both interfaces and more cracks were seen in GI. Groups I and 2"nshowed the least gap formation and group 4 showed the most. Statistically significant difference was found"nbetween groups 3, 4 and group 1 (control, 2."nConclusion: Base

  6. The surface finish of light-cured composite resin materials.

    Science.gov (United States)

    Sidhu, S K; Henderson, L J

    1993-01-01

    A necessity for any dental restorative material is its ability to take and maintain a smooth surface finish. Composite resin restorative materials with fillers and matrix of differing hardness are difficult to finish and polish. The use of aluminum trioxide discs is a popular and acceptable method of finishing composite restorative materials where the material is accessible. Burs and stones are used for finishing and polishing inaccessible areas. This study was undertaken to compare the surface finish of composite resin restorative material when finished with white stones, superfine diamond burs and aluminum trioxide discs. The finished surface was measured with a profilometer and the roughness average value used to compare the surfaces. The aluminum trioxide discs gave the best and most consistent results. It was possible to attain similar results with the superfine diamond bur. However, the results were highly variable. None of the methods used achieved the smoothness of composite resin cured against a transparent matrix.

  7. Thermal expansion characteristics of light-cured dental resins and resin composites.

    Science.gov (United States)

    Sideridou, Irini; Achilias, Dimitris S; Kyrikou, Eleni

    2004-07-01

    The thermal expansion characteristics of dental resins prepared by light-curing of Bis-GMA, TEGDMA, UDMA, Bis-EMA(4) or PCDMA dimethacrylate monomers and of commercial light-cured resin composites (Z-100 MP, Filtek Z-250, Sculpt-It and Alert), the organic matrix resin of which is based on different combinations of the above monomers, were studied by thermomechanical analysis (TMA). This study showed the existence of a glass transition temperature at around 35-47 degrees C for the resins and 40-45 degrees C for the composites; then the coefficient of linear thermal expansion (CLTE) was calculated at the temperature intervals 0-60 degrees C, 0-T(g) and T(g)-60 degrees C. The CLTE values of Bis-GMA, TEGDMA and UDMA resins are similar and lower than those of Bis-EMA (4) and PCDMA resins. The CLTE values of the composites indicated that the major factor that affects the CLTE of a composite is the filler content, but it also seems to be affected by the chemical structure of the matrix resin. TMA on water-saturated samples showed that water desorption takes place during the measurement and that the residual water acts as a plasticizer decreasing the T(g) and increasing the CLTE values. Furthermore, TMA on post-heated samples for 1, 3 or 6h showed, only for the resins, an initial decrease of CLTE and increase of the T(g) after 1h that was not significantly changed after 6h of heating.

  8. The effect of light-cured nanofilled composite resin shades on their under-surface temperature

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    Hanum, U. A.; Herda, E.; Indrani, D. J.

    2017-08-01

    The objective of this study was to observe the effect of shades of light-cured nanofilled composite resins on their under-surface temperature. Resin composites specimens of shades bright, medium, and dark shade were obtained from a cylindrical mold. While polymerizing using a curing unit, the under-surface temperature was determined at the bottom of the specimens using a thermocouple wire 20 sec after the start. Results showed that the under-surface temperature of the darker shade specimens were relatively higher that those of the brighter shades with significant diffferences between the resin composites of different shades. To conlude, the under-surface temperature of the light-cured nanofilled resin composites raised from the brighter to the darker shades.

  9. Bond Strength of Repaired Acrylic Denture Teeth Using Visible Light Cure Composite Resin.

    Science.gov (United States)

    Muhsin, Saja Ali

    2017-01-01

    Although bonding to denture teeth after surface treatment with chemical agents is desirable, there is little information on the use of Visible Light Cure composite resin (VLC) as bonding denture materials. To determine the effect of various surface treatments on shear bond strength between Visible Light Cure composite resin and the acrylic denture teeth interface. Forty cylindrical sticks of acrylic resin with denture teeth mounted atop were prepared. Various treatments were implemented upon the acrylic resin teeth surfaces. The samples were divided into four groups (n = 10). Light-cured composite resin (LC) was applied over all treated and untreated surfaces of tested groups. The shear bond was tested using a universal tensile testing apparatus with the knife-edge of a 0.8mm shear tester. Data were statistically analyzed using one-way ANOVA performed at a confidence level of 95% and significant P-value of (P ≤ 0.05). Analysis of variance (ANOVA) showed statistically significant difference (P resin denture teeth resulted in maximum bond strength with composite resin.

  10. Effects of Different Light Curing Units/Modes on the Microleakage of Flowable Composite Resins

    OpenAIRE

    Yazici, A. Ruya; Celik, Cigdem; Dayangac, Berrin; Ozgunaltay, Gul

    2008-01-01

    Objectives The aim of this in vitro study was to evaluate the influence of different light curing units and modes on microleakage of flowable composite resins. Methods Eighty Class V cavities were prepared in buccal and lingual surfaces of 40 extracted human premolars with cervical wall located in dentin and the occlusal wall in enamel. These teeth were randomly assigned into two groups (n=20) and restored with different flowable composites; Group I: Esthet-X Flow, Group II: Grandio Flow. Eac...

  11. Influence of light curing and sample thickness on microhardness of a composite resin

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    Flávio HB Aguiar

    2009-05-01

    Full Text Available Flávio HB Aguiar1, Kelly RM Andrade1, Débora AN Leite Lima1, Gláucia MB Ambrosano2, José R Lovadino11Department of Restorative Dentistry; 2Department of Social Dentistry/Statistics, Piracicaba Dental School, State University of Campinas, SP, BrazilAbstract: The aim of this in vitro study was to evaluate the influence of light-curing units and different sample thicknesses on the microhardness of a composite resin. Composite resin specimens were randomly prepared and assigned to nine experimental groups (n = 5: considering three light-curing units (conventional quartz tungsten halogen [QTH]: 550 mW/cm2 – 20 s; high irradiance QTH: 1160 mW/cm2 – 10 s; and light-emitting diode [LED]: 360 mW/cm2 – 40 s and three sample thicknesses (0.5 mm, 1 mm, and 2 mm. All samples were polymerized with the light tip 8 mm away from the specimen. Knoop microhardness was then measured on the top and bottom surfaces of each sample. The top surfaces, with some exceptions, were almost similar; however, in relation to the bottom surfaces, statistical differences were found between curing units and thicknesses. In all experimental groups, the 0.5-mm-thick increments showed microhardness values statistically higher than those observed for 1- and -2-mm increments. The conventional and LED units showed higher hardness mean values and were statistically different from the high irradiance unit. In all experimental groups, microhardness mean values obtained for the top surface were higher than those observed for the bottom surface. In conclusion, higher levels of irradiance or thinner increments would help improve hybrid composite resin polymerization.Keywords: photo-polymerization, light-curing distance, light-curing units, composite resin, composite thickness, microhardness

  12. Influence of composition on rate of polymerization contraction of light-curing resin composites.

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    Asmussen, Erik; Peutzfeldt, Anne

    2002-06-01

    A slow contraction may result in reduced gap formation when a restorative resin polymerizes in a dental cavity. It was the aim in the present work to investigate the rate of contraction in relation to composition of experimental light-curing resin composites. The monomer of the resin composites consisted of mixtures of BisGMA, TEGDMA, and in one series HEMA. The resins contained varying amounts of initiators, co-initiators, and inhibitor, and were made composite by adding a silanized glass filler to a content of 74% by weight of the composite paste. The polymerization contraction up to 120 sec was determined by means of the bonded-disk method. Within the ranges studied, the concentration of initiator and co-initiator in the monomer mixture had only an insignificant influence on rate of polymerization. In comparison to camphorquinone, the initiators 1-phenyl-1,2-propanedione and benzil reduced the rate of polymerization without affecting the final contraction. In comparison to N,N-dimethyl-p-aminobenzoic acid ethyl ester, N,N-cyanoethyl methylaniline was as effective, while N,N-diethanol-p-toluidine was less effective as co-initiator. A relatively high content of the inhibitor methoxyhydroquinone reduced the initial rate but not the final polymerization contraction. The rate of polymerization increased with the level of HEMA and TEGDMA in the monomer mixture. It was concluded that intrinsic slow cure may be obtained with certain compositions of resin composites without impairing the final extent of polymerization.

  13. Effect of incremental filling technique on adhesion of light-cured resin composite to cavity floor.

    Science.gov (United States)

    Chikawa, Hirokazu; Inai, Norimichi; Cho, Eitetsu; Kishikawa, Ryuzo; Otsuki, Masayuki; Foxton, Richard M; Tagami, Junji

    2006-09-01

    The purpose of this study was to evaluate the effect of various incremental filling techniques on adhesion between composite and cavity floor using light-cured resin composite. Black ABS resin and hybrid resin composite were used as mold materials--instead of dentin--for the preparation of cavities, and standardized to 5x5x5 mm. Each cavity was then treated with a bonding system (Clearfil SE bond). Resin composite (Clearfil Photo Core) was placed on the bonding resin using different incremental filling techniques or in bulk and irradiated for a total of 80 seconds using a halogen light unit. Specimens were subjected to the micro-tensile bond test at a crosshead speed of 1 mm/min. Data were analyzed by two-way ANOVA. The results indicated that an incremental filling technique was more effective in improving adhesion to the cavity floor than a bulk filling technique.

  14. Effect of inhomogeneity of light from light curing units on the surface hardness of composite resin.

    Science.gov (United States)

    Arikawa, Hiroyuki; Kanie, Takahito; Fujii, Koichi; Takahashi, Hideo; Ban, Seiji

    2008-01-01

    This study investigated the characteristics of output light from different types of light curing units, and their effects on polymerization of light-activated composite resin. Three quartz-tungsten-halogen lamps, one plasma arc lamp, and one LED light curing unit were used. Intensity distribution of light emitted from the light guide tip was measured at 1.0-mm intervals across the guide tip. Distribution of Knoop hardness number on the surface of resin irradiated with the light curing units was also measured. For all units, inhomogeneous distribution of light intensity across the guide tip was observed. Minimum light intensity values were 19-80% of the maximum values. In terms of surface hardness, inhomogeneous distribution was also observed for the materials irradiated with the tested units. Minimum values were 53-92% of the maximum values. Our results indicated that markedly inhomogeneous light emitted from light curing unit could result in inhomogeneous polymerization in some areas of the restoration below the light guide tip.

  15. Effect of delayed light curing of a resin composite on marginal integrity in cylindrical dentine cavities.

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    Manabe, A; Debari, K; Itoh, K; Hisamitsu, H; Wakumoto, S

    1993-12-01

    The effect of delayed light curing of resin composite on marginal adaptation has been examined by measuring the wall-to-wall polymerization contraction gap when using a commercial resin composite together with experimental dentine bonding systems to restore cylindrical preparations in dentine. Morphological changes in dentine during dentine bonding procedures were observed using a scanning electron microscope. In a previous report, the contraction gap width for a resin composite increased when irradiation of the resin system was delayed, despite the use of a dentine bonding system considered to be 'contraction' gap free. Such deterioration in marginal adaptation was minimized by use of an experimental dentine primer, 40% erythritol methacrylate aqueous solution (EM), followed by the use of a commercial dual- or autocured dentine bonding agent. Under scanning electron microscopy, the dentine surface microstructure became unclear after EM priming, and a polymer film was detected after polymerization of the dual-cured dentine bonding agent. The hydrogelled primer and the formation of a polymer network on the dentine surface may prevent the flow of fluid from the pulp through the dentine tubules, and maintain marginal integrity if there is delay in light curing of light-activated resin composite systems.

  16. Color stability of visible light cured composite resin after soft drink immersion

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    Alizatul Khairani Hasan

    2009-09-01

    Full Text Available Background: Composite resin is a tooth-colored filling material containing Bis-GMA which exhibits water sorption properties. People tend to consume soft drink with various colors. Water sorption properties can alter the color stability of composite resin purpose. Purpose: This study was to determine the influence of immersion durations of composite resin in soft drink on color stability. Methods: The visible-light cured hybrid composite resin and soft drink were used. Ten disk specimens (2.5 mm thickness and 15 mm diameter of composite resin were prepared and light cured for 20 seconds, then stored in distilled water for 24 hours at 37° C. The initial color of specimens were measured by Chromameter. After that, each specimen was immersed in 30 ml of soft drink up to 48, 72, and 96 hours at 37° C. The specimens’ color were measured again after each immersion. The color changes were calculated by CIE L*a*b* system formula. The data was analyzed by One-Way ANOVA and LSD (α = 0.05. Result: The ANOVA showed that the immersion durations of composite resin in soft drinks had significant influence on the color stability (p < 0.05. The LSD0.05 tests showed significant differences among all groups. The least color change was detected from the group of 48 hours immersion, while the greatest color change was from the group of 96 hours immersion. Conclusions: The immersion of composite resin in soft drinks influenced the color stability (began after 48 hours immersion.

  17. Paired observation on light-cured composite resin and nano-composite resin in dental caries repair.

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    Xiaoling, Tao; Ashraf, Muhammad Aqeel; Yanyan, Zhao

    2016-11-01

    To compare the value of light-cured composite resin with that of nano-composite resin in dental caries repair. 88 patients taking dental caries repair in our hospital from May 2014 to April 2015 were selected, and divided into observation group and control group by coin method with 44 patients in each group. Nano-composite resin was used in observation group, while light-cured composite resin in control group. Then, the occurrence rates of odontohyperesthesia, aesthetic satisfaction with dental caries repair and complications were compared between two groups by visual analogue scale (VAS). The occurrence rate of odontohyperesthesia in observation group is significantly lower than that in control group (9.09% (4/44) vs 31.82% (14/44), 6.82% (3/44) vs 22.73% (10/44), 2.27% (1/44) vs 13.64% (6/44)) with difference of statistical significance (Pcomposite resin can lower the occurrence rate of odontohyperesthesia in dental caries repair, reduce the pain of patients, and improve the satisfaction of patients with tooth appearance.

  18. Under-surface hardness of light-cured nanofilled resin composites of different shades

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    Ramanitya, A.; Indrani, D. J.; Herda, E.

    2017-08-01

    The objective of the this study was to analyze the under-surface hardness of light-cured nanofilled composite resins of different shades. The specimens were resin composites of each light (B1), medium (A3), and dark (C3) shades packed in a cylinder mold and subsequently polymerized. The hardness was tested using a Knoop system. The hardness test results for the bright (B1), medium (A3), and dark (C3) shades were 82.4+1.1, 75.9+1.2 and 65.9+1.9, respectively, and indicated significant differences between the under-surface hardness of each shade. It was concluded that resin composites of darker to brigher shades demonstrated lower to higher under-surface hardness.

  19. Influence of light curing and sample thickness on microhardness of a composite resin.

    Science.gov (United States)

    Aguiar, Flávio Hb; Andrade, Kelly Rm; Leite Lima, Débora An; Ambrosano, Gláucia Mb; Lovadino, José R

    2009-01-01

    The aim of this in vitro study was to evaluate the influence of light-curing units and different sample thicknesses on the microhardness of a composite resin. Composite resin specimens were randomly prepared and assigned to nine experimental groups (n = 5): considering three light-curing units (conventional quartz tungsten halogen [QTH]: 550 mW/cm(2) - 20 s; high irradiance QTH: 1160 mW/cm(2) - 10 s; and light-emitting diode [LED]: 360 mW/cm(2) - 40 s) and three sample thicknesses (0.5 mm, 1 mm, and 2 mm). All samples were polymerized with the light tip 8 mm away from the specimen. Knoop microhardness was then measured on the top and bottom surfaces of each sample. The top surfaces, with some exceptions, were almost similar; however, in relation to the bottom surfaces, statistical differences were found between curing units and thicknesses. In all experimental groups, the 0.5-mm-thick increments showed microhardness values statistically higher than those observed for 1- and -2-mm increments. The conventional and LED units showed higher hardness mean values and were statistically different from the high irradiance unit. In all experimental groups, microhardness mean values obtained for the top surface were higher than those observed for the bottom surface. In conclusion, higher levels of irradiance or thinner increments would help improve hybrid composite resin polymerization.

  20. 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.

  1. Measurement of linear polymerization shrinkage in light cure Ideal Makoo composite resin

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    Ghavam M.

    2001-09-01

    Full Text Available "nAbstract: Polymerization shrinkage of light cure composite resins causes many complications in conservative and esthetic restorations. The objective of this in-vitro study was to evaluate the polymerization shrinkage, degree of conversion and the amount of filler in IDM and tetric ceram composites. Ten disk shaped, uncured specimens (8mm×1.547mm of each composite were placed on glass slide in the center of the metal attached to it. Then specimens were light cured for 60s from underneath. After 30 minutes, the thickness of specimens, using a micrometer and the percent of the polymerization shrinkage of each sample were measured. Statistical analysis was carried out by t-test (P<0.05. Also the degree of conversion of specimens was evaluated with FTIR and the mineral filler content was measured by burning in electric oven. Polymerization shrinkage in IDM and tetric ceram was not significantly different. Degree of conversion and mineral filler content in tetric ceram was greater than that of IDM. "nIt is assumed that the low degree of conversion in IDM is due to its chemical composition and filler content. Also, the similarity in linear polymerization shrinkage between IDM and tetric ceram may be caused by the low degree of conversion in IDM.

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

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    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.

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

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    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.

  4. Polymerization contraction of resin composite vs. energy and power density of light-cure.

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    Asmussen, Erik; Peutzfeldt, Anne

    2005-10-01

    This study measured the polymerization contraction of a resin composite cured at three levels of energy density, each attained at six different levels of power density. The polymerization contraction of the composite was recorded by the method of the deflecting disc (n = 5) for 1 h following the start of irradiation. Power densities of 50, 100, 200, 400, 800 and 1,000 mW cm(-2), as measured on a dental radiometer, were obtained by variation of distance and supply voltage of a commercial light-curing unit. The spectral distribution at each power density was recorded using a spectrophotometer. The absorption spectrum of camphorquinone was also recorded, and the efficiency of the radiation at each power density was calculated as the integral over wavelength of the product of absorption and emission. From the slope of the contraction curves, an approximation to the initial rate of polymerization, Rp, was calculated and was taken as an alternative measure of power density. Statistical analyses showed that polymerization contraction increased significantly with increasing levels of energy density received by the resin composite, and, for each level of energy density, that the contraction decreased significantly with increasing power density.

  5. Analysis of gap formation at tooth-composite resin interface: effect of C-factor and light-curing protocol

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    Gustavo Oliveira dos Santos

    2007-08-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the effect of C-factor and light-curing protocol on gap formation in composite resin restorations. Material and METHODS: Cylindrical cavities with 5.0 mm diameter and three different depths (A=1.0, B=2.0 and C=3.0 mm were prepared on the occlusal surface of 30 human molars and restored in a single increment with P 60. The composite resin was light-cured according to two protocols: standard - 850 mW/cm² / 20 s and gradual - 100 up to 1000 mW/cm² / 10 s + 1000 mW/cm² / 10 s. After storage in distilled water (37°C/7 days, the restorations were cut into three slices in a buccolingual direction and the gap widths were analyzed using a 3D-scanning system. The data were submitted to ANOVA and Student-Newman-Keuls test (alpha=0.05. RESULTS: ANOVA detected a significant influence for the C-factor and light-curing protocol as independent factors, and for the double interaction C-factor vs. light-curing protocol. Cavities with higher C-factor presented the highest gap formation. The gradual light-curing protocol led to smaller gap formation at cavity interfaces. CONCLUSIONS: The findings of this study suggest that the C-factor played an essential role in gap formation. The gradual light-curing protocol may allow relaxation of composite resin restoration during polymerization reaction.

  6. [The surface degradation of various light-cured composite resins by thermal cycling].

    Science.gov (United States)

    Hirabayashi, S; Nomoto, R; Harashima, I; Hirasawa, T

    1990-01-01

    The durability of four commercially available light-cured composite resins was investigated by thermal cycling, GR containing inorganic fillers treated with the graft polymerization of acryl ester, LF inorganic fillers treated with a silane coupling agent, PC silanized inorganic fillers and organic composite fillers, and the MFR-type SI containing the organic composite fillers. These materials were given 10,000, 30,000 and 50,000 thermal cycles (4 degrees C-60 degrees C) and the deterioration of materials by thermal cycling was evaluated by the measurement of the mechanical properties and the SEM observations of the surface of the thermocycled materials. Compressive strength and bending elastic moduli for all materials did not change greatly by thermal cycling. However, bending strength, toothbrush abrasion resistance and surface hardness decreased with increasing number of thermal cycles between 0 and 30,000, and changed little after 30,000 cycles. The percentage of bending strength after 50,000 thermal cycles to that of the non-thermocycled sample was 75% for GR, 60% for LF, 50% for PC and 65% for SI, respectively. Deterioration of materials was observed as cracks on the surface, which generated at the interface of the filler and matrix. The cracks generated relatively earlier during thermal cycling for SI and PC which contained the organic composite filler, later for LF which contained the silanized inorganic fillers, and the number of cracks on LF were fewer than SI and PC. On the other hand, for GR, no cracks were observed even after 50,000 thermal cycles. From these results, it can be presumed that the pre-treatment of filler by the graft polymerization is more effective to improve the durability of composite resin.

  7. Influence of pre-heat treatment and different light-curing units on Vickers hardness of a microhybrid composite resin

    Science.gov (United States)

    Saade, E. G.; Bandeca, M. C.; Rastelli, A. N. S.; Bagnato, V. S.; Porto-Neto, S. T.

    2009-06-01

    The aim of this study was to evaluate the hardness of a dental composite resin submitted to temperature changes before photo-activation with two light-curing unite (LCUs). Five samples (4 mm in diameter and 2 mm in thickness) for each group were made with pre-cure temperatures of 37, 54, and 60°C. The samples were photo-activated with a conventional quartz-tungsten-halogen (QTH) and blue LED LCUs during 40 s. The hardness Vickers test (VHN) was performed on the top and bottom surfaces of the samples. According to the interaction between light-curing unit and different pre-heating temperatures of composite resin, only the light-curing unit provided influences on the mean values of initial Vickers hardness. The light-curing unit based on blue LED showed hardness mean values more homogeneous between the top and bottom surfaces. The hardness mean values were not statistically significant difference for the pre-cure temperature used. According to these results, the pre-heating of the composite resin provide no influence on Vickers hardness mean values, however the blue LED showed a cure more homogeneous than QTH LCU.

  8. Effect of light-curing units and activation mode on polymerization shrinkage and shrinkage stress of composite resins.

    Science.gov (United States)

    Lopes, Lawrence Gonzaga; Franco, Eduardo Batista; Pereira, José Carlos; Mondelli, Rafael Francisco Lia

    2008-01-01

    The aim of this study was to evaluate the polymerization shrinkage and shrinkage stress of composites polymerized with a LED and a quartz tungsten halogen (QTH) light sources. The LED was used in a conventional mode (CM) and the QTH was used in both conventional and pulse-delay modes (PD). The composite resins used were Z100, A110, SureFil and Bisfil 2B (chemical-cured). Composite deformation upon polymerization was measured by the strain gauge method. The shrinkage stress was measured by photoelastic analysis. The polymerization shrinkage data were analyzed statistically using two-way ANOVA and Tukey test (p contraction and the stress values when compared to CM. LED generated the same stress as QTH in conventional mode. Regardless of the activation mode, SureFil produced lower contraction and stress values than the other light-cured resins. Conversely, Z100 and A110 produced the greatest contraction and stress values. As expected, the chemically cured resin generated lower shrinkage and stress than the light-cured resins. In conclusion, The PD mode effectively decreased contraction stress for Z100 and A110. Development of stress in light-cured resins depended on the shrinkage value.

  9. Dentin Bond Strength of Two One-Bottle Adhesives after Delayed Activation of Light-Cured Resin Composites

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    F. Shafiei

    2007-12-01

    Full Text Available Objective: Adverse surface interactions between one-bottle adhesives and chemical-cured composites may occur with delayed light activation of light-cured composites. The purpose of this study was to assess the Effects of delayed activation of light-cured compositeson shear bond strength of two one-bottle adhesives with different acidity to bovine dentin.Materials and Methods: Flat dentin surface was prepared on sixty-six bovine incisors using 600 grit carbide papers. Prime&Bond NT, and One-Step adhesives and resin composite were applied in six groups: 1 immediate curing of the composite, 2 the composite was left 2.5 minutes over the cured adhesive before light activation, 3 prior to delayed activation of the composite, the cured adhesive was covered with a layer of nonacidic hydrophobic porcelain bonding resin (Choice 2 and cured immediately. After thermocycling,shear bond strength (SBS test was performed using a universal testing machine at 1 mm/min crosshead speed. Data were analyzed with Friedmans two-way Non-parametric ANOVA.Results: The SBS of delayed activation of Prime&Bond was significantly lower than immediate activated (P<0.05. Decrease in the SBS of One-Step was not statistically significant after delayed activation. The SBS of delayed activation of Prime&Bond and One-Step with an additional resin layer was significantly higher than delayed activation (P<0.001.Conclusion: The bond strength of Prime&Bond might be compromised by the higher acidity of this adhesive during the 2.5 minutes delayed activation of light-cured composite.Addition of a layer of hydrophobic resin compensated the effect of delayed activation andimproved the bond strength.

  10. Effect of light-curing units and activation mode on polymerization shrinkage and shrinkage stress of composite resins

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    Lawrence Gonzaga Lopes

    2008-02-01

    Full Text Available The aim of this study was to evaluate the polymerization shrinkage and shrinkage stress of composites polymerized with a LED and a quartz tungsten halogen (QTH light sources. The LED was used in a conventional mode (CM and the QTH was used in both conventional and pulse-delay modes (PD. The composite resins used were Z100, A110, SureFil and Bisfil 2B (chemical-cured. Composite deformation upon polymerization was measured by the strain gauge method. The shrinkage stress was measured by photoelastic analysis. The polymerization shrinkage data were analyzed statistically using two-way ANOVA and Tukey test (p<0.05, and the stress data were analyzed by one-way ANOVA and Tukey's test (p<0.05. Shrinkage and stress means of Bisfil 2B were statistically significant lower than those of Z100, A110 and SureFil. In general, the PD mode reduced the contraction and the stress values when compared to CM. LED generated the same stress as QTH in conventional mode. Regardless of the activation mode, SureFil produced lower contraction and stress values than the other light-cured resins. Conversely, Z100 and A110 produced the greatest contraction and stress values. As expected, the chemically cured resin generated lower shrinkage and stress than the light-cured resins. In conclusion, The PD mode effectively decreased contraction stress for Z100 and A110. Development of stress in light-cured resins depended on the shrinkage value.

  11. Curing kinetics of visible light curing dental resin composites investigated by dielectric analysis (DEA).

    Science.gov (United States)

    Steinhaus, Johannes; Hausnerova, Berenika; Haenel, Thomas; Großgarten, Mandy; Möginger, Bernhard

    2014-03-01

    During the curing process of light curing dental composites the mobility of molecules and molecule segments is reduced leading to a significant increase of the viscosity as well as the ion viscosity. Thus, the kinetics of the curing behavior of 6 different composites was derived from dielectric analysis (DEA) using especially redesigned flat sensors with interdigit comb electrodes allowing for irradiation at the top side and measuring the ion viscosity at the bottom side. As the ion viscosities of dental composites change 1-3 orders of magnitude during the curing process, DEA provides a sensitive approach to evaluate their curing behavior, especially in the phase of undisturbed chain growth. In order to determine quantitative kinetic parameters a kinetic model is presented and examined for the evaluation of the ion viscosity curves. From the obtained results it is seen that DEA might be employed in the investigation of the primary curing process, the quality assurance of ingredients as well as the control of processing stability of the light curing dental composites. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  12. Influence of curing tip distance on resin composite Knoop hardness number, using three different light curing units.

    Science.gov (United States)

    Caldas, Danilo Biazzetto de Menezes; de Almeida, Janaina Bertoncelo; Correr-Sobrinho, Lourenço; Sinhoreti, Mário Alexandre Coelho; Consani, Simonides

    2003-01-01

    This in vitro study evaluated the influence of curing tip distance on the Knoop Hardness Number (KHN) of a resin composite when using three different light curing units: (1) a halogen light (XL 1500 curing unit-3M), (2) a "softstart-polymerization" (Elipar Trilight curing in an exponential mode-ESPE) and (3) a PAC (Apolo 95E curing unit-DMD). The resin composite, Filtek Z250 (3M), was cured by these curing units at three light-tip distances from the resin composite: 0 mm, 6 mm and 12 mm. The resin composite specimens were flattened to their middle portion and submitted to 18 KHN measurements perspecimen. The results showed that for the Elipar Trilight unit, the hardness of the resin composite decreased as the light tip distance increased. The XL 1500 unit presented a significant decrease in hardness as the depth of cure of the resin composite increased. Apolo 95E caused a decrease in the resin composite hardness values when the depth of cure and light tip distance increased.

  13. Elution study of unreacted Bis-GMA, TEGDMA, UDMA, and Bis-EMA from light-cured dental resins and resin composites using HPLC.

    Science.gov (United States)

    Sideridou, Irini D; Achilias, Dimitris S

    2005-07-01

    In the present work the elution of residual monomers from light-cured dental resins and resin composites into a 75% ethanol:water solution was studied using High-Performance Liquid Chromatography (HPLC). The resins studied were made by light-curing of bisphenol A glycol dimethacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), ethoxylated bisphenol A glycol dimethacrylate [Bis-EMA(4)] and mixtures of these monomers. The resin composites were made from two commercial light-cured restorative materials (Z100 MP and Filtek Z250), the resin matrix of which is based on copolymers of these monomers. The effect of the curing time on the amount of monomers eluted was investigated. The concentration of the extractable monomers was determined at several immersion periods from 3 h to 30 days. For all the materials studied, it was observed that the chemical structure of the monomers used for the preparation of the resins, which defines the chemical and physical structure of the corresponding resin, directly affects the amount of eluted monomers, as well as the time needed for the elution of this amount. In the case of composites, it seems that the elution process it is not influenced by the presence of filler. Copyright 2005 Wiley Periodicals, Inc.

  14. Influence of the light-curing unit, storage time and shade of a dental composite resin on the fluorescence

    Science.gov (United States)

    Queiroz, R. S.; Bandéca, M. C.; Calixto, L. R.; Gaiao, U.; Cuin, A.; Porto-Neto, S. T.

    2010-07-01

    The aim of this study was to determine the influence of three light-curing units, storage times and colors of the dental composite resin on the fluorescence. The specimens (diameter 10.0 ± 0.1 mm, thickness 1.0 ± 0.1 mm) were made using a stainless steel mold. The mold was filled with the microhybrid composite resin and a polyethylene film covered each side of the mold. After this, a glass slide was placed on the top of the mold. To standardize the top surface of the specimens a circular weight (1 kg) with an orifice to pass the light tip of the LCU was placed on the top surface and photo-activated during 40 s. Five specimens were made for each group. The groups were divided into 9 groups following the LCUs (one QTH and two LEDs), storage times (immediately after curing, 24 hours, 7 and 30 days) and colors (shades: A2E, A2D, and TC) of the composite resin. After photo-activation, the specimens were storage in artificial saliva during the storage times proposed to each group at 37°C and 100% humidity. The analysis of variance (ANOVA) and Tukey’s posthoc tests showed no significant difference between storage times (immediately, 24 hours and 30 days) ( P > 0.05). The means of fluorescence had difference significant to color and light-curing unit used to all period of storage ( P 0.05).

  15. Effect of light curing modes and ethanol immersion media on the susceptibility of a microhybrid composite resin to staining.

    Science.gov (United States)

    Aguiar, Flávio Henrique Baggio; Oliveira, Thalita Regina Vieira E; Lima, Débora Alves Nunes Leite; Paulillo, Luis Alexandre Maffei Sartini; Lovadino, José Roberto

    2007-04-01

    The aim of this in vitro study was to evaluate the susceptibility of a hybrid composite resin (Filtek Z250 - 3M ESPE) to staining, when light cured in four different modes and immersed in two different media. Composite resin specimens were randomly prepared and polymerized according to the experimental groups (conventional -50 mW/cm(2) / 30 seconds; soft start -300 mW/cm(2) / 10 seconds + 550 mW/cm(2) / 20 seconds; high intensity -1060 mW/cm(2)--10 seconds; pulse delay -550 mW/cm(2)--1 seconds + 60 seconds of waiting time + 550 mW/cm(2)--20 seconds) and immersed in one of two media (distilled water or absolute ethanol) for 24 h. Next, the specimens were immersed in a 2% methylene blue solution for 12 hours. Afterwards, the specimens were washed and prepared for the spectrophotometric analysis. For statistical analysis, two-way ANOVA (4X2) and Tukey's test were performed on the data at 0.05 confidence level. Soft start showed the least staining, and was statistically different from the high intensity and pulse delay light curing modes (p0.05). There were no significant differences between the two immersion media (p>0.05). The soft start polymerization mode showed lower susceptibility of the composite resin to staining than high intensity and pulse delay, irrespective of the immersion medium.

  16. Effect of light curing modes and ethanol immersion media on the susceptibility of a microhybrid composite resin to staining

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    Flávio Henrique Baggio Aguiar

    2007-04-01

    Full Text Available The aim of this in vitro study was to evaluate the susceptibility of a hybrid composite resin (Filtek Z250 - 3M ESPE to staining, when light cured in four different modes and immersed in two different media. Composite resin specimens were randomly prepared and polymerized according to the experimental groups (conventional - 550 mW/cm² / 30 seconds; soft start - 300mW/cm² / 10 seconds + 550 mW/cm² / 20 seconds; high intensity - 1060 mW/cm² - 10 seconds; pulse delay - 550 mW/cm² - 1 seconds + 60 seconds of waiting time + 550 mW/cm² - 20 seconds and immersed in one of two media (distilled water or absolute ethanol for 24h. Next, the specimens were immersed in a 2% methylene blue solution for 12 hours. Afterwards, the specimens were washed and prepared for the spectrophotometric analysis. For statistical analysis, two-way ANOVA (4X2 and Tukey's test were performed on the data at 0.05 confidence level. Soft start showed the least staining, and was statistically different from the high intensity and pulse delay light curing modes (p0.05. There were no significant differences between the two immersion media (p>0.05. The soft start polymerization mode showed lower susceptibly of the composite resin to staining than high intensity and pulse delay, irrespective of the immersion medium.

  17. Polymerization contraction of light-cured composite resins containing silica/polymethylmethacrylate bonded microstructured networks.

    Science.gov (United States)

    Pefferkorn, A; Haïkel, Y; Pefferkorn, E

    2005-11-15

    The adsorption of methylmethacrylate polymer at silica/methylmethacrylate interfaces was determined to provide microstructured networks whose structural characteristics were determined to be controlled by the amount of polymer initially supplied to the system. First, the microstructure was investigated by determining as a function of the amount of polymer (i) the shrinking rate due to evaporation of the methylmethacrylate monomer, (ii) the rate of sedimentation of the silica/polymer complexes in the methylmethacrylate monomer, and (iii) the height of the sediment in the long term. These different characteristics were found to be strongly correlated. Second, the sedimentation characteristics were determined as a function of the amount of polymer initially supplied to the dispersion of the same silica/polymer system in the ethylene glycol dimethacrylate monomer. Then the rate of the polymerization contraction during light-curing of the resin was determined for the sediment recovered after centrifugation. The slowest polymerization contraction and the smallest contraction were obtained with the filler/polymer/resin system composed of aggregates of medium porosity and size.

  18. Physical properties of current dental nanohybrid and nanofill light-cured resin composites.

    Science.gov (United States)

    Sideridou, Irini D; Karabela, Maria M; Vouvoudi, Evangelia Ch

    2011-06-01

    The purpose of this work was the detailed study of sorption characteristics of water or artificial saliva, the determination of flexural strength and the flexural modulus, and the study of the thermal stability of some current commercial dental light-cured nanocomposites containing nano-sized filler particles. Three nanohydrid dental composites (Tetric EvoCeram (TEC), Grandio (GR) and Protofill-nano (PR)) and two nanofill composites (Filtek Supreme Body (FSB) and the Filtek Supreme Translucent (FST)) were used in this work. The volumetric shrinkage due to polymerization was first determined. Also the sorption, solubility and volumetric increase were measured after storage of composites in water or artificial saliva for 30 days. The flexural strength and flexural modulus were measured using a three-point bending set-up according to the ISO-4049 specification, after immersion of samples in water or artificial saliva for 1 day or 30 days. Thermal analysis technique TGA method was used to investigate the thermal stability of composites. GR and TEC composites showed statistically no difference in volumetric shrinkage (%) which is lower than the other composites, which follow the order PRcomposites studied the amount of water, which is sorbed (% on composite) is not statistically different than the amount of water, which is desorbed and follows the order: GRcomposites after immersion for one day follows the order TECcomposites studied, Grandio had the lowest polymer matrix content, consisting mainly of Bis-GMA. It showed the lowest polymerization shrinkage and water sorption and the highest flexural strength and flexural modulus after immersion in water or artificial saliva for 30 days. The water and artificial saliva generally showed the same effect on physical properties of the studied composites. Thermogravimetric analysis gave good information about the structure and the amount of organic polymer matrix of composites. Copyright © 2011 Academy of Dental Materials

  19. Water sorption characteristics of light-cured dental resins and composites based on Bis-EMA/PCDMA.

    Science.gov (United States)

    Sideridou, Irini; Achilias, Dimitris S; Spyroudi, Chrysa; Karabela, Maria

    2004-01-01

    The water uptake characteristics of resins and composites based on an ethoxylated bisphenol A glycol dimethacrylate (Bis-EMA) and a polycarbonate dimethacrylate (PCDMA) were studied in detail. Polydimethacrylate resins were prepared by photopolymerization of the neat monomers and mixtures of them with various weight ratios, using the camphoroquinone/N,N-dimethylaminoethyl methacrylate system as initiator, while the composites were prepared from the light-curing of commercial samples (Sculpt-It and Alert). Water sorption/desorption was examined both in equilibrium and dynamic conditions in two adjacent sorption-desorption cycles. The equilibrium water uptake from all resins was very small with a trend to increase as the amount of PCDMA was increased. The inverse effect was observed in the solubility values. The composites studied exhibited also very low water uptake values in comparison to other composite materials reported in the literature. It was also observed that the equilibrium uptake decreased with increasing filler loading. Slightly larger equilibrium water uptake and much smaller solubility values were obtained during the second sorption-desorption cycle in comparison to the first one. Concerning the sorption rate data, it was observed that the resin materials followed Fickian diffusion during almost the whole sorption or desorption curve, while the composites showed this behavior until only M(t)/M( infinity ) congruent with 0.5. The diffusion coefficients calculated for the resins were larger than those of the composites and always higher during desorption compared to sorption. The values of the diffusion coefficients for both resins and composites were in the same order of magnitude with the values of the corresponding materials reported in the literature.

  20. Influence of Sealer and Light-Curing Units on Push-Out Bond Strength Of Composite Resin to Weakened Roots.

    Science.gov (United States)

    Lima, Adriana Corrêa de; Rached-Junior, Fuad Jacob; Faria, Natália Spadini de; Messias, Danielle Cristine; Chaves, Carolina de Andrade Lima; Freitas, Jessica Vavassori de; Baratto-Filho, Flares; Silva-Sousa, Yara Teresinha Corrêa

    2016-01-01

    The aim of this study was to assess the influence of sealer and light-curing unit on regional bond strength of resin composite to the weakened roots. Ninety roots of incisors were experimentally weakened, subjected to biomechanical preparation and filled with either Endofill, AH Plus or MTA Fillapex The roots were desobturated e reinforced with resin composite and fiber post light-activated with one of the light sources: halogen at 600 mW/ cm2 (QTH-600), LED at 800 mW/ cm2 (LED-800) and LED at 1500 mW/ cm2 (LED-1500). The roots were sectioned in slices from cervical, middle and apical root-reinforcement regions and analyzed by push out test, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Bond strength data were analyzed using three-way ANOVA and Tukey´s test (α=0.05). Specimens filled with AH Plus had higher bond strength, followed by MTA Fillapex and Endofill (pfilling material in the dentinal tubules for all groups. The eugenol-containing sealer (Endofill) compromised the push-out bond strength of composite resin to the root dentin. Bond strength was favored in the cervical region, and when LED-1500 was used.

  1. Influence of light-curing unit systems on shear bond strength and marginal microleakage of composite resin restorations

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    Juliano Fernandes Sassi

    2008-03-01

    Full Text Available The aim of the present study was to evaluate the influence of different photopolymerization (halogen, halogen soft-start and LED systems on shear bond strength (SBS and marginal microleakage of composite resin restorations. Forty Class V cavities (enamel and dentin margins were prepared for microleakage assessment, and 160 enamel and dentin fragments were prepared for the SBS test, and divided into 4 groups. Kruskal-Wallis and Wilcoxon tests showed statistically significant difference in microleakage between the margins (p 0.05 neither between substrates nor among groups. It was concluded that Soft-Start technique with high intensity end-light influenced negatively the cervical marginal sealing, but the light-curing systems did not influence adhesion.

  2. Effect of food/oral-simulating liquids on dynamic mechanical thermal properties of dental nanohybrid light-cured resin composites.

    Science.gov (United States)

    Vouvoudi, Evangelia C; Sideridou, Irini D

    2013-08-01

    The purpose of this work was the study of the effect of food/oral simulating liquids on the dynamic mechanical thermal properties (viscoelastic properties) of current commercial dental light-cured resin composites characterized as nanohybrids. These nanohybrids were Grandio, Protofill-nano and Tetric EvoCeram. The properties were determined under dry conditions (1h at 37°C after light-curing) and also after storage in dry air, distilled water, artificial saliva SAGF(®) or ethanol/water solution (75 vol%) at 37°C for up 1, 7, 30 or 90 days. Dynamic mechanical thermal analysis tests were performed on a Diamond Dynamic Mechanical Analyzer in bending mode. A frequency of 1Hz and a temperature range of 25-185°C were applied, while the heating rate of 2°C/min was selected to cover mouth temperature and the materials' likely Tg. Storage modulus, loss modulus and tangent delta were plotted against temperature over this period. The Tg of composites was obtained as the temperature indicated by tanδ peak. Moreover, the maximum height of tanδ peak, the width at the half of tanδ maximum and a parameter known as "ζ" parameter were determined. All composites analyzed 1h after light-curing and 1 day in air or in food/oral simulating liquids showed two Tg. All composites stored for 7, 30 or 90 days in any medium showed unique Tg value. Also among the various properties studied the most sensible in the structural changes of composites seems to be the Tg. Storage of composites in dry air at 37°C which is very close to their Tg (40°C) for 1 or 7 days caused post curing reactions, while storage for 30 or 90 days has no further effect on composites. Storage in water or artificial saliva 37°C for 1 or 7 days caused post curing reactions, while storage for 30 or 90 days seems to cause plasticization effect affecting some parameters analogously. Storage in ethanol/water solution (75vol%) 37°C for 1 or 7 days caused also post curing reactions, while storage for 30 or 90 days

  3. Dynamic mechanical properties of dental nanofilled light-cured resin composites: Effect of food-simulating liquids.

    Science.gov (United States)

    Vouvoudi, Evangelia C; Sideridou, Irini D

    2012-06-01

    This work is aimed at the study by dynamic mechanical analysis (DMA) of viscoelastic properties that is, the elastic modulus (E'), the loss modulus (E″), the loss tangent (tanδ) and the glass transition temperature (T(g)), of two current commercial light-cured resin composites, Filtek Supreme Body and Filtek Supreme Translucent, characterized as nanofilled. These composites show differences in the filler content and type. For DMA analysis the bar-shaped specimens were divided into groups of three samples each. The first group consisted of dry samples measured 1 h after light-curing (at room temperature) during which they were placed in a desiccator at 37 °C. The other groups consisted of samples which had been stored in air, distilled water, artificial saliva SAGF or ethanol/water solution (75 v/v), at 37±1 °C for 1, 7, 30 or 90 days. DMA tests were performed on a Diamond Dynamic Mechanical Analyzer (Perkin-Elmer) in bending mode. A frequency of 1 Hz was applied and a temperature range of 25-185 °C, while a heating rate of 2 °C/min were selected to cover mouth temperature and the materials' likely T(g). The studied dry composites showed comparable values for their properties in spite of their differences in the filler content and type. Storage of composites in air 37 °C for 1 day caused a significant post curing which was not continued during storage up to 90 days. Water and artificial saliva showed the same effect on composites. They caused both post curing and plasticization. Ethanol/water solution 75% v/v had a more strong effect than water and artificial saliva due to its organophilic nature. It caused post curing, plasticization and most probably degradation of the bond filler-silane coupling agent. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. A review of the development of radical photopolymerization initiators used for designing light-curing dental adhesives and resin composites.

    Science.gov (United States)

    Ikemura, Kunio; Endo, Takeshi

    2010-10-01

    This paper reviews our recent studies on radical photopolymerization initiators, which are used in the design of light-curing dental adhesives and resin composites, by collating information of related studies from original scientific papers, reviews, and patent literature. The photopolymerization reactivities of acylphosphine oxide (APO) and bisacylphosphine oxide (BAPO) derivatives, and D,L-camphorquinone (CQ)/tertiary amine were investigated, and no significant differences in degree of conversion (DC) were found between BAPO and CQ/amine system (p>0.05). In addition, a novel 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carbonyldiphenyl phosphine oxide (DOHC-DPPO=CQ-APO) was synthesized and its ultraviolet and visible (UV-VIS) spectral behavior was investigated. CQ-APO possessed two maximum absorption wavelengths (λmax) at 350-500 nm [372 nm (from APO group) and 475 nm (from CQ moiety)], and CQ-APO-containing resins exhibited good photopolymerization reactivity, excellent color tone, relaxed operation time, and high mechanical strength. It was also found that a newly synthesized, water-soluble photoinitiator (APO-Na) improved adhesion to ground dentin.

  5. Light-cured resin for post patterns.

    Science.gov (United States)

    Waldmeier, M D; Grasso, J E

    1992-09-01

    A method of using light-cured acrylic resin as an alternative to the use of chemically-cured acrylic resins with elastomeric impressions for direct post patterns is presented. The GC Unifast LC acrylic resin is a powder/liquid type resin cured by exposure to visible light. The polymerization process has four stages before final curing: slurry, stringy, dough-like (plastic), and rubber-like (elastic). Advantages over current direct and indirect procedures include ease of manipulation of the material and no change in laboratory handling procedures. While in the dough-like state, the material can be contoured. In the rubber-like state, it is flexible to disengage from minor undercut areas.

  6. Thermal analysis of bulk filled composite resin polymerization using various light curing modes according to the curing depth and approximation to the cavity wall

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    Hoon-Sang Chang

    2013-07-01

    Full Text Available OBJECTIVE: The purpose of this study was to investigate the polymerization temperature of a bulk filled composite resin light-activated with various light curing modes using infrared thermography according to the curing depth and approximation to the cavity wall. MATERIAL AND METHODS: Composite resin (AeliteFlo, Bisco, Schaumburg, IL, USA was inserted into a Class II cavity prepared in the Teflon blocks and was cured with a LED light curing unit (Dr's Light, GoodDoctors Co., Seoul, Korea using various light curing modes for 20 s. Polymerization temperature was measured with an infrared thermographic camera (Thermovision 900 SW/TE, Agema Infra-red Systems AB, Danderyd, Sweden for 40 s at measurement spots adjacent to the cavity wall and in the middle of the cavity from the surface to a 4 mm depth. Data were analyzed according to the light curing modes with one-way ANOVA, and according to curing depth and approximation to the cavity wall with two-way ANOVA. RESULTS: The peak polymerization temperature of the composite resin was not affected by the light curing modes. According to the curing depth, the peak polymerization temperature at the depth of 1 mm to 3 mm was significantly higher than that at the depth of 4 mm, and on the surface. The peak polymerization temperature of the spots in the middle of the cavity was higher than that measured in spots adjacent to the cavity wall. CONCLUSION: In the photopolymerization of the composite resin, the temperature was higher in the middle of the cavity compared to the outer surface or at the internal walls of the prepared cavity.

  7. Thermal analysis of bulk filled composite resin polymerization using various light curing modes according to the curing depth and approximation to the cavity wall

    Science.gov (United States)

    CHANG, Hoon-Sang; CHO, Kyu-Jeong; PARK, Su-Jung; LEE, Bin-Na; HWANG, Yun-Chan; OH, Won-Mann; HWANG, In-Nam

    2013-01-01

    Objective The purpose of this study was to investigate the polymerization temperature of a bulk filled composite resin light-activated with various light curing modes using infrared thermography according to the curing depth and approximation to the cavity wall. Material and Methods Composite resin (AeliteFlo, Bisco, Schaumburg, IL, USA) was inserted into a Class II cavity prepared in the Teflon blocks and was cured with a LED light curing unit (Dr's Light, GoodDoctors Co., Seoul, Korea) using various light curing modes for 20 s. Polymerization temperature was measured with an infrared thermographic camera (Thermovision 900 SW/TE, Agema Infra-red Systems AB, Danderyd, Sweden) for 40 s at measurement spots adjacent to the cavity wall and in the middle of the cavity from the surface to a 4 mm depth. Data were analyzed according to the light curing modes with one-way ANOVA, and according to curing depth and approximation to the cavity wall with two-way ANOVA. Results The peak polymerization temperature of the composite resin was not affected by the light curing modes. According to the curing depth, the peak polymerization temperature at the depth of 1 mm to 3 mm was significantly higher than that at the depth of 4 mm, and on the surface. The peak polymerization temperature of the spots in the middle of the cavity was higher than that measured in spots adjacent to the cavity wall. Conclusion In the photopolymerization of the composite resin, the temperature was higher in the middle of the cavity compared to the outer surface or at the internal walls of the prepared cavity. PMID:24037066

  8. The effect of surface roughness on repair bond strength of light-curing composite resin to polymer composite substrate.

    Science.gov (United States)

    Kallio, Timo T; Tezvergil-Mutluay, Arzu; Lassila, Lippo V J; Vallittu, Pekka K

    2013-01-01

    The purpose of this study was to analyze the shear bond strength of a new composite resin to polymer-based composite substrates using various surface roughnesses and two kinds of polymer matrices. Particulate filler composite resin with cross-linked polymer matrix and fiber-reinforced composite with semi-interpenetrating polymer matrix were used as bonding substrates after being ground to different roughnesses. Substrates were aged in water for one week before bonding to new resin composites. Twelve specimens in the substrate groups were ground with grinding papers of four grits; 320, 800, 1200 and 2400. Corresponding values of surface roughness (Ra) varied from 0.09 to 0.40 for the particulate filler composite resin and 0.07 to 0.96 for the fiber-reinforced composite resin. Characteristic shear bond strength between the new resin and particulate filler composite resin was highest (27.8 MPa) with the roughest surface (Weibull modulus: 2.085). Fiber-reinforced composite showed the highest bond strength (20.8 MPa) with the smoothest surface (Weibull modulus: 4.713). We concluded that surface roughness did not increase the bonding of new resin to the substrate of IPN based fiber-reinforced composite, whereas the roughness contributed to bonding the new resin to the particulate filler composite resin with a cross-linked polymer matrix.

  9. The application of fluorinated aromatic dimethacrylates to experimental light-cured radiopaque composite resin, containing barium-borosilicate glass filler--a progress in nonwaterdegradable properties.

    Science.gov (United States)

    Tanaka, J; Inoue, K; Masamura, H; Matsumura, K; Nakai, H; Inoue, K

    1993-06-01

    This study investigated the durability, especially the nonwaterdegradable qualities, of experimental light-cured composite resin containing barium-borosilicate glass filler. For this purpose, Bis-GMA, a typical component of base monomer in conventional composite resin, was replaced by Bis-GMA-F which is water-repellent. After over 20,000 thermal cycles, the composite resin containing Bis-GMA retained only 60 approximately 70% of its initial compressive, diametral tensile, flexural strength and flexural elastic modulus. However, the experimental composite resin containing Bis-GMA-F as a resin matrix showed no loss of compressive, diametral tensile strength or flexural elastic modulus, although flexural strength showed some deterioration. It was considered that the difference between Bis-GMA-F and Bis-GMA, as resin matrix, caused variation in the characteristics of water sorption.

  10. Effects of irradiance, wavelength, and thermal emission of different light curing units on the Knoop and Vickers hardness of a composite resin.

    Science.gov (United States)

    Torno, Vladja; Soares, Paulo; Martin, Juliana M H; Mazur, Rui F; Souza, Evelise M; Vieira, Sérgio

    2008-04-01

    The aim of this study was to evaluate the effects of irradiance, light emission wavelength, and heating of different light curing units on the Knoop and Vickers hardness of a hybrid composite resin. The specimens were irradiated during 40 s with ten different light curing units, LEDs, and halogen lights. The spectral emission of each light curing unit was assessed by a spectrometer, the irradiance was measured by two commercial radiometers, and the heating measured with a thermocouple. After 48 h of storage in a dark recipient under a 100% humidity condition, the Knoop and Vickers hardness tests were carried out. The hardness results were analyzed by ANOVA, and Tukey HSD test (p surface hardness of the composite resin depends not only on the irradiance, but strongly on the emission wavelength and heating of the light curing units. It was observed, a linear correlation between the conversion degree and radiant exposure. In addition, it is suggested that the well known base to top surface hardness ratio convention of 80-90% is not appropriate to evaluate curing efficiency of composites, since the top surface is not always sufficiently polymerized.

  11. The effects of halogen and light-emitting diode light curing on the depth of cure and surface microhardness of composite resins

    Directory of Open Access Journals (Sweden)

    Batu Can Yaman

    2011-01-01

    Full Text Available Aim : Light-emitting diode light curing units (LED LCUs have become more popular than halogen LCUs in routine dental restorative treatment. The aim of the study was to compare the effects of two conventional halogen (Hilux Plus and VIP and two LED (Elipar FreeLight 2 and Smart Lite light curing units on the depth of cure and the microhardness of various esthetic restorative materials. Materials and Methods : The curing depth and microhardness of a compomer (Dyract Extra, a resin-modified glass ionomer (Vitremer, a packable composite (Sculpt It, an ormocer (Admira, a hybrid composite (Tetric Ceram, two microhybrid composites (Miris and Clearfil Photo Posterior and, a nanofil composite (Filtek Supreme were determined using a scraping method and a hardness tester. A total of 320 samples were prepared using the eight different materials (n = 10 samples for each subgroup. The scraping test was based on ISO 4049:2000. Vicker′s microhardness testing was carried out using hardness tester (Zwick 3212. Data were analyzed using one-way analysis of variance (ANOVA, Bonferroni and the Kolmogorov-Smirnov tests. Results : Best microhardness results were obtained with the LED light curing units and Tetric EvoCeram and Filtek Supreme achieved the highest hardness values. The nanofil composite, Filtek Supreme, showed the best curing depth results in all the tested light curing systems. Conclusions : The LEDs were found to be more successful than the halogen units with respect to both curing depth and microhardness properties.

  12. Effect of cross infection control barriers used on the light-curing device tips on the cure depth of a resin composite

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Celerino de Moraes Porto

    2013-01-01

    Full Text Available Background: Among the advice on prevent cross-infection was included usage of mechanical barriers on tips of photoactivation units. However, questions about the use of protective barriers placed on the light-curing unit′s tips and the possibility of interference with the ability of guaranteeing an effective polymerization of composite resins need to be clarified. Aims: The aim of this study was to evaluate the effect of cross infection control barriers used on the light-curing device tips on the cure depth of composite resin. Materials and Methods: Power density measurements from the light-cure unit were recorded with a radiometer on ten separate occasions with different types and placement modes of each barrier (low-density polyethylene and polyvinyl chloride (PVC film - smooth and folds and no-barrier (control. Cure depth of TPH™ Spectrum™ resin, A2-A4, was evaluated by the scraping test. Statistical Analysis: The data were analyzed using Student′s t-test or ANOVA one-way with Tukey′s test (α =0.05. Results: Same type of barrier and different shades (A2, A4 of composite exhibited significant difference in the cure depth among all groups (P < 0.05. Both low-density polyethylene and PVC film folded barriers produced a significant reduction in the light intensity (P < 0.05. Conclusions: Regarding the resin shade, there was a significant reduction in the cure depth of A4 composite resin (dark shade but this reduction is not enough to cause any adverse effect on the material′s clinical performance. Therefore, disposable barriers can be recommended for use over the end of the light guide.

  13. Effects of distance from tip of LED light-curing unit and curing time on surface hardness of nano-filled composite resin

    Science.gov (United States)

    Shafadilla, V. A.; Usman, M.; Margono, A.

    2017-08-01

    Polymerization process depends on several variables, including the hue, thickness, and translucency of the composite resin, the size of the filler particles, the duration of exposure to light (the curing time), the intensity of the light, and the distance from the light. This study aimed to analyze the effects of the distance from the tip of the light-emitting diode (LED) light-curing unit and of curing time on the surface hardness of nano-filled composite resin. 60 specimens were prepared in a mold and divided into 6 groups based on various curing distances and times: 2 mm, 5 mm, and 8 mm and 20 seconds and 40 seconds. The highest surface hardness was seen in the group both closest to the tip and having the longest curing time, while the lowest hardness was seen in the group both farthest from the tip and having the shortest curing time. Significant differences were seen among the various tip distances, except for in the two groups that had 8-mm tip distances, which had no significant differences due to curing time. Both decreased distance from the tip of the LED light-curing unit and increased curing time increase the surface hardness of nano-filled composite resin. However, curing time increases the surface hardness only if the tip distance is ≤ 5 mm.

  14. Photothermal radiometry monitoring of light curing in resins

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano-Arjona, M A [Applied Physics Department, Cinvestav-Unidad Merida, A.P. 73 Cordemex, Merida, 97310 (Mexico); Medina-Esquivel, R [Cinvestav-Unidad Queretaro, Libramiento Norponiente 2000 Fracc. Real de Juriquilla, CP 76230, Queretaro (Mexico); Alvarado-Gil, J J [Applied Physics Department, Cinvestav-Unidad Merida, A.P. 73 Cordemex, Merida, 97310 (Mexico)

    2007-10-07

    Real time measurement of thermal diffusivity during the evolution of the light curing process in dental resins is reported using photothermal radiometry. The curing is induced by a non-modulated blue light beam, and at the same time, a modulated red laser beam is sent onto the sample, generating a train of thermal waves that produce modulated infrared radiation. The monitoring of this radiation permits to follow the time evolution of the process. The methodology is applied to two different commercially available light curing resin-based composites. In all cases thermal diffusivity follows a first order kinetics with similar stabilization characteristic times. Analysis of this kinetics permits to exhibit the close relationship of increase in thermal diffusivity with the decrease in monomer concentration and extension of the polymerization in the resin, induced by the curing light. It is also shown that the configuration in which the resin is illuminated by the modulated laser can be the basis for the development of an in situ technique for the determination of the degree of curing.

  15. The effect of light curing units, curing time, and veneering materials on resin cement microhardness

    Directory of Open Access Journals (Sweden)

    Nurcan Ozakar Ilday

    2013-06-01

    Conclusion: Light-curing units, curing time, and veneering materials are important factors for achieving adequate dual cure resin composite microhardness. High-intensity light and longer curing times resulted in the highest microhardness values.

  16. 光固化复合树脂的乳光及荧光性能%Opalescence and fluorescence properties of light-cured resin composites

    Institute of Scientific and Technical Information of China (English)

    陈豆豆; 李继遥

    2011-01-01

    背景:光固化复合树脂在现代牙科美容修复中占重要位置,泛用于临床牙体缺损的直接修复,产生与牙体相似的颜色效果.目的:综述光固化复合树脂乳光、荧光效应的影响因素及研究现状.方法:由第一作者检索1989-01/2010-11中国期刊全文数据库和PubMed数据库,文检索词"光固化复合树脂,色,光,光",文检索词"resin composite,llumination,iller,cattering,palescence,luorescence,olor",检到129篇文献,纳入排除标准,留34篇归纳总结.结果与结论:光固化复合树脂材料能模拟天然牙的乳光性、荧光性,中,固化复合树脂中直径接近蓝光的无机填料对蓝光的散射、感光的有机基质对紫外光的吸收可以模拟天然牙,别产生材料的乳光或荧光效应;它们受光源条件、材料状态以及临床相关操作等的影响,可以影响光固化复合树脂的遮色力.%BACKGROUND: In esthetic restorative dentistry, light-cured resin composites are widely applied in direct repairing dental defects due to their excellent color performance.OBJECTIVE: To review research status of influencing factors on the opalescence and fluorescence of light-cured resin composites.METHODS: Databases of CNKI and PubMed were retrieved by the first author to research the papers with the key words of "resin composite, illumination, filler, scattering, opalescence, fluorescence, color". Papers underlying light mechanism,characteristics, and research status were included. In total 129 documents were initial searched, and 34 ones were included in the final analysis.RESULTS AND CONCLUSION : The light-cured resin composites, in particular, scattering of inorganic filler with similar diameter to blue light and absorption of photoreceptive organic matrix to ultraviolet light, have similar properties of opalescence and fluorescence as those of natural teeth. Opalescence and fluorescence of light-cured resin composite were affected by illumination, resin composition

  17. Clinical Stomatology Cosmetology Repair with Light Cured Composite Resin%光固化复合树脂临床口腔美容修复

    Institute of Scientific and Technical Information of China (English)

    王黎

    2014-01-01

    Objective:To study the effect of the application of light cured composite resin in clinical stomatology repair. Method:Collecting 87 cases of stomatology cosmetology repair with light cured composite resin in the hospital,and to observing the clinical efficacy and adverse reactions. Result:The total effective rate of the treatment group was 85.1%,and the total complication rate was 14.8%. The effective rate of dental fluorosis group was significantly higher than that of dentition malformation or absence of group, and the incidence of complications was significantly lower than that of the latter(P<0.05). Conclusion:Light cured composite resin used in dental cosmetic repair has obvious curative effect,simple operation and less complications,which can effectively protect the teeth,so it is worthy of popularization and application.%目的:研究光固化复合树脂在口腔美容修复中的应用效果。方法:收集我院接受口腔美容修复的患者87例,应用光固化复合树脂进行治疗,观察其临床疗效及不良反应。结果:本组87例患者的治疗总有效率为85.1%,总并发症发生率为14.8%。其中,氟斑牙组的治疗有效率显著高于牙列畸形或缺失组,而并发症发生率显著低于后者(P<0.05)。结论:光固化复合树脂用于口腔美容修复,疗效显著,操作简便、并发症少,可有效保护牙体,值得推广应用。

  18. Light-cured dimethacrylate-based resins and their composites: comparative study of mechanical strength, water sorption and ion release

    Science.gov (United States)

    O’Donnell, J.N.R.; Langhorst, S.E.; Fow, M.D.; Antonucci, J.M.; Skrtic, D.

    2008-01-01

    This study explored how resin type affects selected physicochemical properties of complex methacrylate copolymers and their amorphous calcium phosphate (ACP)-filled and glass-filled composites. Two series of photo-polymerizable resin matrices were formulated employing 2,2-bis[p-(2’-hydroxy-3’-methacryloxypropoxy)phenyl]propane (Bis-GMA) or an ethoxylated bisphenol A dimethacrylate (EBPADMA) as the base monomer, Unfilled copolymers and composites filled with a mass fraction with 40 %, 35 % and 30 %, respectively, of ACP or the un-silanized glass were assessed for biaxial flexure strength (BFS), water sorption (WS) and mineral ion release upon immersion in HEPES-buffered saline solution for up to six months. Substituting EBPADMA for Bis-GMA significantly reduced the WS while only marginally affected the BFS of both dry and wet copolymers. Independent of the filler level, both dry and wet ACP composites formulated with either BTHM or ETHM resins were mechanically weaker than the corresponding copolymers. The BFS of ACP composite specimens after 1 month in saline did not further decrease with further aqueous exposure. The BFS of glass-filled composites decreased with the increased level of the glass filler and the time of aqueous exposure. After 6 months of immersion, the BFS of glass-filled BTHM and ETHM composites, respectively, remained 58 % and 41 % higher than the BFS of the corresponding ACP composites. Ion release data indicated that a minimum mass fraction of 35 % ACP was required to attain the desired solution supersaturation with respect to hydroxyapatite for both the BTHM and ETHM derived composites. PMID:18607513

  19. 光固化复合树脂治疗牙体病牙位的疗效%Effect of light-cured composite resin on dental disease

    Institute of Scientific and Technical Information of China (English)

    王燕

    2016-01-01

    目的:探讨光固化复合树脂用于治疗牙体病牙位的临床疗效。方法选取2012年8月至2013年10月于驻马店市第二中医院口腔修复科治疗牙体病患者78例作为研究对象,患者通过光固化复合树脂进行治疗,分析其治疗牙体病牙位的疗效。通过观察前牙和双尖牙牙位变化对牙体出现磨损,形态是否保持良好,牙体是否出现变色,并观察其契合度及不良反应等指标。结果在牙体病的治疗过程中,通过光固化复合树脂材料的应用,可以减少牙体病患者对牙体的磨损,保持牙体形态良好,与患者的牙齿契合度较高,患者未出现任何不适。结论把光固化复合树脂材料应用于牙体病牙位治疗中,可以有效提高患者牙齿的美观度,并且对于患者牙齿修复的固化方面也有较好的效果,能够改善患者牙齿修复的舒适度,具有较高的临床意义,值得临床推广。%Objective To investigate the effect of light-cured composite resin on dental disease. Methods From August 2012 to December 2013, Seventy eight patients with dental disease in hospital were selected as the objects of study. The patients were given light-cured composite resin dental treatment, the effect was analyzed. The anterior and bicuspid tooth for tooth abrasion level changes, tooth shape, tooth discoloration, and the fit and adverse reactions were observed. Results During the treatment of dental disease, light cured composite resin materials, can reduce tooth abrasion, maintain good tooth shape, have higher tooth fit, and there was no any discomfort. Conclusions The light-cured composite resin material applied to dental treatment can effectively improve the appearance of the teeth of the patient, and has good effect on immobilization dental restoration, can improve patient comfort in dental restoration, has high clinical significance, so it is worthy of promotion.

  20. Comparison of Mechanical Properties of Two Kinds of Light-cure Composite Resins.%两种光固化树脂材料机械性能的对比研究

    Institute of Scientific and Technical Information of China (English)

    迟惠熔; 陈力; 刘静; 马肃

    2011-01-01

    目的:探讨光固化流体树脂直接用于恒牙早期或可疑窝沟龋微创治疗的可行性.方法:使用万能材料实验机测定两种树脂的机械性能,用t检验方法进行统计学分析.结果:光固化流体树脂的压缩强度和挠曲强度分别为(284.41±24.33)MPa和(104.28±15.31)MPa,与后牙树脂的(320.34±29.59)MPa和(109.44±14.56)MPa无显著性差别,两种材料的弹性模量分别为(6.00±0.567)GPa和(12.10±0.884)GPa,光固化流体树脂小于后牙树脂(P<0.05).结论:光固化流体树脂是一种值得临床推广的微创充填材料.%Obieetive: To explore the feasibility of light-cure flowable resin in minimal invasive treatment of permanent teeth with early or suspicious pit-and-fissure caries. Methods: We tested the mechanical properties of two kinds of materials with a universal material testing machine. The results were analyzed by t-test. Results: The compressive strength and flexural strength of light-cure flowable resin were(284. 414± 24.33)MPa and(104.28 ± 15.31)MPa respectively, and the measurements for light-cure posterior composite resin were(320.34 4±29. 59) MPa and(109. 44±14.56) MPa. There were no statistically significant differences. The elastic modulus of lightcure flowable resin and light-cure posterior composite resin were (6. 004±0. 567)GPa and (12. 104±0. 884)GPa respectively. The light-cure flowable resin was lower than light-cure posterior composite resin(P<0.05). Conclusion: The light-cure flowable resin is worth to apply clinically.

  1. Pengaruh ketebalan bahan dan lamanya waktu penyinaran terhadap kekerasan permukaan resin komposit sinar (Effects of materials thickness and length of light exposure on the surface hardness light-cured composite resins

    Directory of Open Access Journals (Sweden)

    Annette Alexandra Susanto

    2006-03-01

    Full Text Available Light-cured resin composite is one of the most commonly used molding materials due to its easy-to-mold characteristic. Nevertheless, care must be taken while treating this material, especially with respect to material thickness and how long it is exposed to light. Failure to treat the material with these optimal parameters will result in undesired hardness. To determine the most favorable value of these two parameters, an experiment was done with 3 different material thicknesses, and 3 different exposure times. After the sample of the resin composite was removed from its molding, it was stored under humid condition for 24 hours. Afterwards hardness test was done on the sample using Micro Vickers Hardness tester from this experiment, the significant difference in hardness was obtained and the maximum hardness was evaluated from the resin composite sample with 2 mm thickness and 60 seconds light exposure.

  2. Effect of High-Irradiance Light-Curing on Micromechanical Properties of Resin Cements

    Science.gov (United States)

    Peutzfeldt, Anne; Lussi, Adrian

    2016-01-01

    This study investigated the influence of light-curing at high irradiances on micromechanical properties of resin cements. Three dual-curing resin cements and a light-curing flowable resin composite were light-cured with an LED curing unit in Standard mode (SM), High Power mode (HPM), or Xtra Power mode (XPM). Maximum irradiances were determined using a MARC PS radiometer, and exposure duration was varied to obtain two or three levels of radiant exposure (SM: 13.2 and 27.2 J/cm2; HPM: 15.0 and 30.4 J/cm2; XPM: 9.5, 19.3, and 29.7 J/cm2) (n = 17). Vickers hardness (HV) and indentation modulus (EIT) were measured at 15 min and 1 week. Data were analyzed with nonparametric ANOVA, Wilcoxon-Mann-Whitney tests, and Spearman correlation analyses (α = 0.05). Irradiation protocol, resin-based material, and storage time and all interactions influenced HV and EIT significantly (p ≤ 0.0001). Statistically significant correlations between radiant exposure and HV or EIT were found, indicating that high-irradiance light-curing has no detrimental effect on the polymerization of resin-based materials (p ≤ 0.0021). However, one resin cement was sensitive to the combination of irradiance and exposure duration, with high-irradiance light-curing resulting in a 20% drop in micromechanical properties. The results highlight the importance of manufacturers issuing specific recommendations for the light-curing procedure of each resin cement. PMID:28044129

  3. Effect of High-Irradiance Light-Curing on Micromechanical Properties of Resin Cements

    Directory of Open Access Journals (Sweden)

    Anne Peutzfeldt

    2016-01-01

    Full Text Available This study investigated the influence of light-curing at high irradiances on micromechanical properties of resin cements. Three dual-curing resin cements and a light-curing flowable resin composite were light-cured with an LED curing unit in Standard mode (SM, High Power mode (HPM, or Xtra Power mode (XPM. Maximum irradiances were determined using a MARC PS radiometer, and exposure duration was varied to obtain two or three levels of radiant exposure (SM: 13.2 and 27.2 J/cm2; HPM: 15.0 and 30.4 J/cm2; XPM: 9.5, 19.3, and 29.7 J/cm2 (n=17. Vickers hardness (HV and indentation modulus (EIT were measured at 15 min and 1 week. Data were analyzed with nonparametric ANOVA, Wilcoxon-Mann-Whitney tests, and Spearman correlation analyses (α=0.05. Irradiation protocol, resin-based material, and storage time and all interactions influenced HV and EIT significantly (p≤0.0001. Statistically significant correlations between radiant exposure and HV or EIT were found, indicating that high-irradiance light-curing has no detrimental effect on the polymerization of resin-based materials (p≤0.0021. However, one resin cement was sensitive to the combination of irradiance and exposure duration, with high-irradiance light-curing resulting in a 20% drop in micromechanical properties. The results highlight the importance of manufacturers issuing specific recommendations for the light-curing procedure of each resin cement.

  4. 光固化复合树脂在口腔美容修复中的作用探讨%Investigate of the Role of Light Cured Composite Resin in Stomatology Cosmetology Repair

    Institute of Scientific and Technical Information of China (English)

    王晓峰

    2014-01-01

    目的:分析讨论光固化复合树脂在口腔美容修复中的作用。方法:选取于本院行口腔美容修复的96例患者,包括氟斑牙,对照组为牙痛畸形及牙体缺损。均应用光固化复合树脂,采取分层塑形固化的方式,进行口腔美容修复。结果:经口腔美容修复患者总有效率为89.6%(86/96)。结论:在口腔美容修复中,经采用光固化复合树脂,患者可获得满意临床疗效,其操作简单,且并发症较少,保持时间长,为口腔美容修复中最佳材料。%Objective:To analyze and discuss the effect of light cured composite resin in stomatology cosmetology repair. Method:Selecting 96 stomatology cosmetology repair patients in the hospital,including dental fluorsis,and the control group had toothache deformity and tooth defect. Both groups had light cured composite resin,and adopted layered shaping curing and stomatology cosmetology repair. Result:Through stamatology cosmetology repair,the total effective rate was 89.6%(86/96). Conclusion:In stomatology cosmetology repair,by using light cured composite resin,patients can obtain satisfactory clinical effect, with simple operation,less complications and long-lasting. Light cured composite resin can provide best material for stomatology cosmetology.

  5. Clinical Application of Light-cured Composite Resin Restoration in Clinical Oral Beauty%光固化复合树脂在临床口腔美容修复中的临床应用

    Institute of Scientific and Technical Information of China (English)

    邓剑兰; 查伯涛

    2013-01-01

    目的:探讨光固化复合树脂在临床口腔美容修复中的疗效。方法:选取氟斑牙患者65例98颗、牙体缺损患者及牙体畸形患者68例100颗,均采用光固化复合树脂进行口腔修复,比较疗效。结果:光固化复合树脂治疗氟斑牙的总有效率为92.9%,对牙体缺损及牙体畸形总有效率为78.0%。结论:光固化复合树脂对口腔美容修复具有较高的实际应用价值,值得临床推广使用。%Objective To investigate the efficacy of light-cured composite resin restoration in the clinical oral beauty. Methods 65 patients with dental fluorosis(98 teeth)and 68 patients with malformations(100 teeth)were carried by light-cured dental composite resin and the efficacy were compared. Results The total efficiency rate of the light-cured composite resin for the treatment of dental fluorosis was 92.9%,and for dental defects and tooth abnormalities 78.0%,respectively. Conclusion Light-cured composite resin for dental cosmetic restoration has high practical value and is worthy of clinical use.

  6. 光固化复合树脂材料修复牙冠缺损的疗效分析%Light-cured composite resin materials for dental crown defective repair

    Institute of Scientific and Technical Information of China (English)

    于华; 张晓东; 王亦菁; 魏静; 刘佼佼; 李予杰

    2013-01-01

    背景:光固化复合树脂修复缺损牙冠,既能修复其应用功能又能修复其形态功能。目的:探讨光固化复合树脂修复牙冠缺损的治疗效果。  方法:应用文献检索的方法获取光固化复合树脂修复牙冠缺损的相关研究文献,对符合研究标准的文献进行深入的数据分析。并将解放军沈阳军区总医院临床应用光固化复合树脂修复牙冠缺损患者的随访治疗效果与文献研究中的结果进行比较,以明确光固化复合树脂修复牙冠缺损应用的可行性。  结果与结论:文献数据研究中,光固化复合树脂材料修复牙冠缺损的成功率达90%以上。临床治疗随访的12例患者修复后检查患牙修复的光固树脂冠稳固,修复的外观与邻牙对侧同名牙对称,有正常的咬颌关系。随访观察修复后的19颗患牙,稳固无松动,无脱落,咬颌关系正常,无叩痛,X射线片显示根尖无阴影。而光照对双固化树脂修复牙冠缺损影响的研究中显示,光固化的效果仅限于根上段和根中段,不能影响根尖段的固化效果,且能够获得较好的治疗效果。%BACKGROUND:Light-cured composite resin is used for dental crown defective repair in terms of both function and morphology. OBJECTIVE:To investigate the therapeutic effects of light-cured composite resins on crown defects. METHODS:Relevant literatures concerning light-cured composite resins for repair of crown defects were retrieved. Literatures which met the study standard were deeply analyzed. Meanwhile, fol ow-up results and literature results were compared for patients receiving light-cured composite resins for repair of crown defects to identify the feasibility of light-cured composite resins for repair of crown defects. RESULTS AND CONCLUSION:Based on the included data, the successful rate of light-cured composite resins for repair of crown defects was over 90%. Clinical fol ow-up of 12

  7. Influência do tipo de ponteira condutora de luz na microdureza de uma resina composta Influence of the different light-curing TIPS in the microhardness of a composite resin

    Directory of Open Access Journals (Sweden)

    Máx Dobrovolski

    2010-01-01

    Full Text Available O objetivo desta pesquisa foi avaliar a influência do tipo de ponteira condutora de luz na microdureza de uma resina composta micro-híbrida. Foram confeccionados 14 corpos de prova da resina composta Opallis (FGM com dimensões: 5 x 2 mm, divididos em dois grupos de acordo com a ponteira condutora de luz do aparelho fotoativador de lâmpada halógena Optilight Plus - GNATUS/300 mW.cm-2. GI - ponteira condutora de luz de fibra óptica; GII - ponteira condutora de luz de polímero. Após 24 horas, as medidas de microdureza foram efetuadas com um microdurômetro HMV 2000 (Shimadzu Japão. Cinco penetrações foram efetuadas em cada superfície (topo e base totalizando 10 penetrações para cada corpo de prova. A análise estatística dos resultados realizada por meio do teste de ANOVA não apresentou diferenças significativas entre os tipos de ponta condutora de luz nas superfícies avaliadas. A análise estatística demonstrou diferença significativa nos valores médios de microdureza superficial entre as superfícies de topo e de base, para ambas as ponteiras. Com base nos resultados obtidos, foi possível concluir que as ponteiras de luz não interferem na microdureza da resina composta, e que ambas apresentaram diferenças estatisticamente significativas nos valores de microdureza das superfícies topo e base.The aim of this study is to evaluate the influence of the light-curing tips on the microhardness of a micro-hybrid composite resin. Fourteen samples of Opallis (FGM composite resin with 5 x 2 mm were prepared. The specimens were divided into two groups according to the light-curing tips from a halogen light curing unit (Optilight Plus -GNATUS/300 mW.cm-2: GI - optical fiber light-curing; GII - polymer light-curing. After 24 hours, the microhardness measurements were determined using the HMV 2000 (Shimadzu Japan. Five measurements were made on each surface (top and bottom totalizing 10 indentations for each sample. Statistical analysis

  8. CURING EFFICIENCY OF DUAL-CURE RESIN CEMENT UNDER ZIRCONIA WITH TWO DIFFERENT LIGHT CURING UNITS

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    Pınar GÜLTEKİN

    2015-04-01

    Full Text Available Purpose: Adequate polymerization is a crucial factor in obtaining optimal physical properties and a satisfying clinical performance from composite resin materials. The aim of this study was to evaluate the polymerization efficiency of dual-cure resin cement cured with two different light curing units under zirconia structures having differing thicknesses. Materials and Methods: 4 zirconia discs framework in 4 mm diameter and in 0.5 mm, 1 mm and 1.5 mm thickness were prepared using computer-aided design system. One of the 0.5 mm-thick substructures was left as mono-layered whereas others were layered with feldspathic porcelain of same thickness and ceramic samples with 4 different thicknesses (0.5, 1, 1.5 and 2.0 mm were prepared. For each group (n=12 resin cement was light cured in polytetrafluoroethylene molds using Light Emitting Diode (LED or Quartz-Tungsten Halogen (QHT light curing units under each of 4 zirconia based discs (n=96. The values of depth of cure (in mm and the Vickers Hardness Number values (VHN were evaluated for each specimen. Results: The use of LED curing unit produced a greater depth of cure compared to QTH under ceramic discs with 0.5 and 1 mm thickness (p<0.05.At 100μm and 300 μm depth, the LED unit produced significantly greater VHN values compared to the QTH unit (p<0.05. At 500 μm depth, the difference between the VHN values of LED and QTH groups were not statistically significant. Conclusion: Light curing may not result in adequate resin cement polymerization under thick zirconia structures. LED light sources should be preferred over QTH for curing dual-cure resin cements, especially for those under thicker zirconia restorations.

  9. 光固化复合树脂在临床口腔美容修复中的临床应用%Light-cured composite resin in clinical dental cosmetic repair of clinical application

    Institute of Scientific and Technical Information of China (English)

    席俊明; 席小茜

    2014-01-01

    目的:探讨光固化复合树脂在临床口腔美容修复中的临床应用效果。方法:选取2011年9月至2014年6月我院收治的100例接受口腔美容修复的患者,随机分成两组,观察组主要为氟斑牙,对照组主要为牙体缺损、畸形,每组50例,两组均采用光固化复合树脂进行口腔美容修复,观察两组的临床修复效果以及不良反应。结果:经治疗,观察组的临床疗效明显高于对照组(94.0%vs80.0%),P<0.05,有统计学意义。结论:采用光固化复合树脂进行临床口腔美容修复,具有操作简便以及并发症较少的优势,能够起到保护牙体的作用,效果显著,尤其适用于氟斑牙的美容修复,值得临床推广。%Objective:To investigate the clinical application of light-cured composite resin results in clinical oral cosmetic repair. Methods:To choose between September 2011 and June 2011,100 cases of our hospital in patients undergoing oral cosmetic repair,randomly divided into two groups,observation group mainly for dental fluorosis,control group is mainly for the tooth defect and deformity,50 cases in each group,two groups are using oral cosmetic repair of light-cured composite resin,observe two groups of clinical repairing effects and adverse reactions. Results:After treatment,the clinical curative effect of observation group was obviously higher than that of control group(94.0% vs80.0 %),P<0.05,with statistical significance. Conclusion:Using clinical dental cosmetic repair of light-cured composite resin,with the advantages of convenient operation and less complications,can protect the tooth,effect is remarkable,especially suitable for cosmetic repair of dental fluorosis,worth clinical promotion.

  10. Do light cured ART conventional high-viscosity glass-ionomer sealants perform better than resin-composite sealants: a 4-year randomized clinical trial

    NARCIS (Netherlands)

    Zhang, W.; Chen, X.; Fan, M.W.; Mulder, J.; Huysmans, M.C.D.N.J.M.; Frencken, J.E.F.M.

    2014-01-01

    OBJECTIVE: The hypotheses tested were: the cumulative survival rates of dentin caries lesion-free pits and fissures of ART conventional high-viscosity glass-ionomer sealants with light-curing (high-intensity LED) and glass-carbomer sealants are higher than those of conventional ART sealants and resi

  11. Micro-hardness evaluation of a micro-hybrid composite resin light cured with halogen light, light-emitting diode and argon ion laser.

    Science.gov (United States)

    Rode, Katia M; de Freitas, Patricia M; Lloret, Patricia R; Powell, Lynn G; Turbino, Miriam L

    2009-01-01

    This in vitro study aimed to determine whether the micro-hardness of a composite resin is modified by the light units or by the thickness of the increment. Composite resin disks were divided into 15 groups (n = 5), according to the factors under study: composite resin thickness (0 mm, 1 mm, 2 mm , 3 mm and 4 mm) and light units. The light activation was performed with halogen light (HL) (40 s, 500 mW/cm(2)), argon ion laser (AL) (30 s, 600 mW/cm(2)) or light-emitting diode (LED) (30 s, 400 mW/cm(2)). Vickers micro-hardness tests were performed after 1 week and were carried out on the top surface (0 mm-control) and at different depths of the samples. Analysis of variance (ANOVA) and Tukey tests (P hardness values than the LED. In groups with 3 mm and 4 mm thickness, the HL also showed higher micro-hardness values than the groups activated by the AL and the LED. Only the HL presented satisfactory polymerization with 3 mm of thickness. With a 4 mm increment no light unit was able to promote satisfactory polymerization.

  12. in vitro evaluation of marginal leakage using invasive and noninvasive technique of light cure glass ionomer and flowable polyacid modified composite resin used as pit and fissure sealant

    Directory of Open Access Journals (Sweden)

    Anshu Singla

    2011-01-01

    Full Text Available Aim: This study compared the microleakage of light cure glass ionomer and flowable compomer as pit and fissure sealant, with and without tooth preparation. Materials and Methods: One hundred premolars that were extracted for orthodontic purpose were used. After adequate storage and surface debridement, the teeth were randomly divided into four groups. In Group I and III, the occlusal surfaces were left intact, while in Group II and Group IV, tooth surfaces were prepared. Teeth in Group I and Group II were sealed with Light cure glass ionomer, whereas flowable compomer was used to seal teeth in Group III and IV. The sealed teeth were then immersed in dye. Subsequently, buccolingual sections were made and each section was examined under stereomicroscope for microleakage followed by scoring. Results: In group I, microleakage score ranged from 2 to 4 with mean of 3.64 (±0.757, while in group II the range was observed to be 1-4 with mean of 2.88 (±1.236. Group III recorded a range of 0-4 with the mean of 2.20 (±1.443 while 0-2 and 0.60 (±0.707 being the range and mean observed, respectively, for group IV. Conclusion: Flowable compomer placed after tooth preparation showed better penetration and less marginal leakage than the light cure glass ionomer.

  13. Volumetric dimensional changes of dental light-cured dimethacrylate resins after sorption of water or ethanol.

    Science.gov (United States)

    Sideridou, Irini D; Karabela, Maria M; Vouvoudi, Evagelia Ch

    2008-08-01

    This study evaluated the influence of water and ethanol sorption on the volumetric dimensional changes of resins prepared by light curing of Bis-GMA, Bis-EMA, UDMA, TEGDMA or D(3)MA. The resin specimens (15mm diameterx1mm height) were immersed in water or ethanol 37+/-1 degrees C for 30 days. Volumetric changes of specimens were obtained via accurate mass measurements using Archimedes principle. The specimens were reconditioned by dry storage in an oven at 37+/-1 degrees C until constant mass was obtained and then immersed in water or ethanol for 30 days. The volumetric changes of specimens were determined and compared to those obtained from the first sorption. Resins showed similar volume increase during the first and second sorptions of water or ethanol. The volume increase due to water absorption is in the following order: poly-TEGDMA>poly-Bis-GMA>poly-UDMA>poly-Bis-EMA>poly-D(3)MA. On the contrary, the order in ethanol is poly-Bis-GMA>poly-UDMA>poly-TEGDMA>poly-Bis-EMA approximately poly-D(3)MA. The volume increase was found to depend linearly on the amount of water or ethanol absorbed. In the choice of monomers for preparation of composite resin matrix the volume increase in the resin after immersion in water or ethanol must be taken into account. Resins of Bis-EMA and D(3)MA showed the lowest values.

  14. The Experiment of Creep with Glass Ionomer Cement and Light-cured Composite Resin%玻璃离子水门汀与光固化复合树脂的蠕变实验

    Institute of Scientific and Technical Information of China (English)

    丁杰; 李新颖; 李鹏; 罗民

    2014-01-01

    通过蠕变实验得出了光固化型玻璃离子水门汀试样、银粉玻璃离子水门汀试样、光固化复合树脂试样的蠕变数据、蠕变曲线,建立了各组试样的蠕变函数方程,对比分析三种材料的蠕变特性,为临床提供蠕变力学参数。取光固化型玻璃离子水门汀试样、银粉玻璃离子水门汀试样、光固化复合树脂试样各10个,在电子万能试验机上进行蠕变实验,模拟人体温在36.5±1℃的温度下,以0.1 Mpa/s 的应力增加速度对试样施加应力,每个试样采集100个实验数据,以归一化分析的方法处理蠕变数据,拟合蠕变曲线。光固化型玻璃离子水门汀试样7200 s蠕变量为0.301%,银粉玻璃离子水门汀试样7200 s蠕变量为0.262%,光固化复合树脂试样7200 s蠕变量为0.230%,光固化型玻璃离子水门汀试样7200 s蠕变量大于银粉玻璃离子水门汀试样7200 s蠕变量,光固化复合树脂试样7200 s蠕变量差异显著(P<0.05)。各组试样蠕变曲线是以指数关系变化的。光固化型玻璃离子水门汀由于采用了光化处理,改善了其蠕变特性。%To get the creep data and the creep curves by creep test with the light cured glass ionomer cement specimen,the glass ionomer cement specimen and the light cured composite resin sample,we established the creep equation of different sample,and we analyzed the creep characteristics of three kinds of materials,which provide a clinical creep parameters were analyed.10 glass ionomer cement specimen of the light cared,10 glass ionomer cement specimen,and the 10 specimen of light cured composite resin sample were taken,and we conducted creep experiments in electronic universal testing machine.We simulated human body temperature at a tem-perature of 36.5 ±0.5 ℃ and applied to the specimen stress with stress increasing speed of 0.1Mpa/s,then 100 experimental data in each of samples were collected,then the

  15. Influence of light curing source on microhardness of composite resins of different shades Influência da fonte de luz polimerizadora na microdureza da resina composta de diferentes cores

    Directory of Open Access Journals (Sweden)

    André Luiz Fraga Briso

    2006-01-01

    Full Text Available INTRODUCTION: The evolution of light curing units can be noticed by the different systems recently introduced. The technology of LED units promises longer lifetime, without heating and with production of specific light for activation of camphorquinone. However, further studies are still required to check the real curing effectiveness of these units. PURPOSE: This study evaluated the microhardness of 4 shades (B-0.5, B-1, B-2 and B-3 of composite resin Filtek Z-250 (3M ESPE after light curing with 4 light sources, being one halogen (Ultralux - Dabi Atlante and three LED (Ultraled - Dabi Atlante, Ultrablue - DMC and Elipar Freelight - 3M ESPE. METHODS: 192 specimens were distributed into 16 groups, and materials were inserted in a single increment in cylindrical templates measuring 4mm x 4mm and light cured as recommended by the manufacturer. Then, they were submitted to microhardness test on the top and bottom aspects of the cylinders. RESULTS: The hardness values achieved were submitted to analysis of variance and to Tukey test at 5% confidence level. It was observed that microhardness of specimens varied according to the shade of the material and light sources employed. The LED appliance emitting greater light intensity provided the highest hardness values with shade B-0.5, allowing the best curing. On the other hand, appliances with low light intensity were the least effective. It was also observed that the bottom of specimens was more sensitive to changes in shade. CONCLUSION: Light intensity of LED light curing units is fundamental for their good functioning, especially when applied in resins with darker shades.INTRODUCTION: A evolução dos aparelhos fotopolimerizadores pode ser notada nos diferentes sistemas introduzidos recentemente no mercado. A tecnologia apresentada pelos aparelhos LED promete maior tempo de vida útil, não gerar aquecimento e produzir luz específica para a ativação da canforoquinona. No entanto, ainda são necess

  16. Feasibility of light-cured composite resin for adult crown restorationduring orthodontic treatment%光固化复合树脂修复成人正畸牙冠缺损的可行性

    Institute of Scientific and Technical Information of China (English)

    程德盛

    2016-01-01

    背景:光固化复合树脂性能好,色泽美观持久,具有一定的的抗压强度,因此被广泛应用于口腔修复,但目前关于其修复成人正畸牙冠缺损的报道相对较少。  目的:探讨光固化复合树脂修复成人正畸牙冠缺损的可行性。  方法:纳入300例成人正畸牙冠缺损患者,其中男160例,女140例,年龄16-41岁,均实施光固化复合树脂充填修复。修复结束后随访36个月,了解修复大体外观效果、临床修复效果及不良反应发生情况。  结果与结论:①经修复,患者咬颌关系正常,光固化树脂冠十分稳固,外观与邻牙对侧同名牙对称,无叩痛,X射线片检查根尖无阴影;②随访36个月,300例患者中,修复成功268例,其余32例出现脱落,修复成功率为89.33%;300例患者中,对修复效果表示满意的有271例,满意率为90.33%,300例患者均未出现严重不良反应;③结果表明:光固化复合树脂修复成人正畸牙冠缺损的成功率及患者满意率高,且无严重不良反应。%BACKGROUND:Because ofgood performance, beautiful and permanent color, andcertain compressive strength,light-cured composite resinhas beenwidely used in dental restoration. Butthere are less reports about its usage inadultcrown restoration during orthodontic treatment. OBJECTIVE:To explore the feasibility of light-cured composite resin in the adult crownres to rationduring orthodontic treatment. METHODS:300 adultcases of crown defectss cheduled for orthodontic treatmentwere enroled, including 160 males and 140 females, aged from16 to 41years. Al the crown defects were filed with light-cured compositeresins. After 36-month folow-up, the gross appearances of repaired teeth,repairingeffect and adverse reactions were statisticaly recorded and analyzed. RESULTS AND CONCLUSION:Afterrestoration, patients exhibited normal occlusion,and thefiled crowns were fixed stably and

  17. Effect of light-curing method and indirect veneering materials on the Knoop hardness of a resin cement

    Directory of Open Access Journals (Sweden)

    Nelson Tetsu Iriyama

    2009-06-01

    Full Text Available This study evaluated the Knoop hardness of a dual-cured resin cement (Rely-X ARC activated solely by chemical reaction (control group or by chemical / physical mode, light-cured through a 1.5 mm thick ceramic (HeraCeram or composite (Artglass disc. Light curing was carried out using conventional halogen light (XL2500 for 40 s (QTH; light emitting diodes (Ultrablue Is for 40 s (LED; and Xenon plasma arc (Apollo 95E for 3 s (PAC. Bovine incisors had their buccal face flattened and hybridized. On this surface a rubber mold (5 mm in diameter and 1 mm in height was bulk filled with the resin cement. A polyester strip was seated for direct light curing or through the discs of veneering materials. After dry storage in the dark (24 h 37°C, the samples (n = 5 were sectioned for hardness (KHN measurements, taken in a microhardness tester (50 gF load 15 s. The data were statistically analyzed by ANOVA and Tukey's test (α = 0.05. The cement presented higher Knoop hardness values with Artglass for QTH and LED, compared to HeraCeram. The control group and the PAC/Artglass group showed lower hardness values compared to the groups light-cured with QTH and LED. PAC/HeraCeram resulted in the worst combination for cement hardness values.

  18. Light-Curing Volumetric Shrinkage in Dimethacrylate-Based Dental Composites by Nanoindentation and PAL Study

    Science.gov (United States)

    Shpotyuk, Olha; Adamiak, Stanislaw; Bezvushko, Elvira; Cebulski, Jozef; Iskiv, Maryana; Shpotyuk, Oleh; Balitska, Valentina

    2017-01-01

    Light-curing volumetric shrinkage in dimethacrylate-based dental resin composites Dipol® is examined through comprehensive kinetics research employing nanoindentation measurements and nanoscale atomic-deficient study with lifetime spectroscopy of annihilating positrons. Photopolymerization kinetics determined through nanoindentation testing is shown to be described via single-exponential relaxation function with character time constants reaching respectively 15.0 and 18.7 s for nanohardness and elastic modulus. Atomic-deficient characteristics of composites are extracted from positron lifetime spectra parameterized employing unconstrained x3-term fitting. The tested photopolymerization kinetics can be adequately reflected in time-dependent changes observed in average positron lifetime (with 17.9 s time constant) and fractional free volume of positronium traps (with 18.6 s time constant). This correlation proves that fragmentation of free-volume positronium-trapping sites accompanied by partial positronium-to-positron traps conversion determines the light-curing volumetric shrinkage in the studied composites.

  19. Evaluation of mechanical properties of Z250 composite resin light-cured by different methods Avaliação de propriedades mecânicas da resina composta Z250 fotoativada com diferentes métodos

    Directory of Open Access Journals (Sweden)

    Andresa Carla Obici

    2005-12-01

    Full Text Available This study evaluated some mechanical parameters of Z250 composite resin using different light-curing methods. Ten specimens were prepared for each mechanical test group with different dimensions according to the test. Light-curing was performed by: a. continuous light (800mW/cm²-40s; b. exponential light (0-800mW/cm²-40s; c. intermittent light (2s-600mW/cm²; 2s without light-80s; d. stepped light (10s-150mW/cm²; 30s-650mW/cm²; e. PAC (1320mW/cm²-3s; f. LED (350mW/cm²-40s. After 24 ± 1 h, the specimens were loaded at a crosshead speed of 0.5 mm/min until fracture. The mechanical properties were calculated and analyzed by ANOVA and Tukey test (5%. The results showed that the highest compressive strength values were found for the continuous, exponential, intermittent and stepped light methods, whereas PAC and LED obtained the lowest values. LED, stepped light, PAC, exponential and continuous light presented the highest values for diametral tensile strength. The intermittent light showed the lowest value, which was significantly lower than the value obtained for LED only. Flexural strength results were not significantly different between all light-curing methods. Finally, the highest modulus of elasticity values were obtained for LED, exponential, continuous and intermittent light, whereas PAC and stepped light showed the lowest values. The mechanical properties were affected by light-curing methods employed.Este estudo avaliou algumas propriedades mecânicas da resina composta Z250 usando diferentes métodos de fotoativação. Dez amostras foram preparadas para cada grupo, com diferentes dimensões de acordo com o ensaio. Os métodos de fotoativação foram: a luz contínua (800mW/cm²-40s; b luz exponencial (0-800mW/cm²-40s; c luz intermitente (2s-600mW/cm²; 2s sem luz-80s; d dupla intensidade (10s-150mW/cm²; 30s-650mW/cm²; e PAC (1320mW/cm²-3s; f LED (350mW/cm²-40s. Após 24 ± 1 h, as amostras foram carregadas até fraturar (v=0

  20. Influence of light-curing mode on the cytotoxicity of resin-based surface sealants

    Science.gov (United States)

    2014-01-01

    Background Surface sealants have been successfully used in the prevention of erosive tooth wear. However, when multiple tooth surfaces should be sealed, the light-curing procedure is very time-consuming. Therefore, the aim of this study was to investigate whether reduced light-curing time (while maintaining similar energy density) has an influence on resin-based surface sealant cytotoxicity. Methods Bovine dentine discs were treated as follows: group 1: untreated, groups 2–5: Seal&Protect and groups 6–9: experimental sealer. Groups 2 and 6 were light-cured (VALO LED light-curing device) for 40 s (1000 mW/cm2), groups 3 and 7 for 10 s (1000 mW/cm2), groups 4 and 8 for 7 s (1400 mW/cm2) and groups 5 and 9 for 3 s (3200 mW/cm2). Later, materials were extracted in culture medium for 24 h, and released lactate dehydrogenase (LDH) activity as a measure of cytotoxicity was determined photometrically after cells (dental pulp cells and gingival fibroblasts) were exposed to the extracts for 24 h. Three independent experiments, for both sample preparation and cytotoxicity testing, were performed. Results Overall, lowest cytotoxicity was observed for the unsealed control group. No significant influence of light-curing settings on the cytotoxicity was observed (p = 0.537 and 0.838 for pulp cells and gingival fibroblasts, respectively). No significant difference in the cytotoxicity of the two sealants was observed after light-curing with same light-curing settings (group 2 vs. 6, 3 vs. 7, 4 vs. 8 and 5 vs. 9: p > 0.05, respectively). Conclusions Shortening the light-curing time, while maintaining constant energy density, resulted in no higher cytotoxicity of the investigated sealants. PMID:24885810

  1. Study of Light Cured Composite Resin Clinical Repair on Teratology Cosmetology%光固化复合树脂临床口腔美容修复的研究

    Institute of Scientific and Technical Information of China (English)

    彭彩燕

    2014-01-01

    目的:探讨针对口腔美容修复中使用光固化复合树脂进行修复的临床疗效和应用价值。方法:选取2004年12月-2006年12月牙科接受治疗的128例患者,均实施光固化复合树脂分层实施塑性固化,对比不同牙科疾病的治疗结果,保持对患者1~6年的随访,观察分析长期效果。结果:45例前牙邻面龋患者治疗优秀36例(80.00%),总有效率91.11%;染色牙、四环素牙、斑釉牙40例患者治疗后优秀32例(80.00%),总有效率90.00%;15例颌面磨损患者治疗后优秀14例(93.33%),总有效率100%;15例折断牙患者治疗后优秀12例(80.00%),总有效率93.33%;8例牙缝间隙修补患者治疗后优秀7例(87.50%),总有效率100%;5例畸形牙患者治疗后优秀3例(60.00%),总有效率80.00%。其中颌面磨损修补优秀率最高,畸形牙修补优秀率最低,两者比较差异有统计学意义(P<0.05)。随访显示共有10例失败,其中1例患者1年之后发生脱落,其余9例患者发生脱落时间为修复后5年。结论:光固化复合树脂用于口腔美容修复,总体临床效果较为理想。光固化复合树脂的选材较为简便,操作过程不复杂,安全性高,且长期效果不错,方便再次修复,值得推广应用。%Objective:To investigate the clinical effect and application value on the use of light cured composite resin dental restoration in the repair. Method:128 cases of patients with dental treatment from December 2004 to December 2006 were selected,the implementation of light-cured composite resin layered implementation plastic solidified,compared the treatment outcome of different dental diseases,keep on patients with 1-6 years of follow-up,observed the long-term effect. Result:45 patients with front teeth adjacent surface caries treatment had 36 cases(80.00%)in excellent,the total effective rate was 91.11%;40 patients with stained teeth

  2. Effects of light-curing modes on the polymerization shrinkage and surface hardness of composite resins%光照模式对复合树脂聚合收缩率和表面硬度的影响

    Institute of Scientific and Technical Information of China (English)

    韩冰; 董艳梅; 王晓燕; 高学军

    2011-01-01

    Objective: To investigate the effects of light-curing modes on the polymerization shrinkage and surface hardness of resins and to explore the related clinical relevance. Methods: Resins with filler content of 76% ( mass fraction) were light-cured by high intensity, low intensity and soft start curing modes for 10 s and 20 s, respectively. Specimens for detecting volumetric shrinkage and surface hardness were prepared. Volumetric shrinkage was measured with Acuvol (n =7) and surface hardness were tested with an indenter (n=5). Results: The volumetric shrinkage of composites cured by high intensity, low intensity and soft-start curing mode was: 2.95% ±0. 08%/3.06% ±0.03% (10 s/20 s), 2.98% ± 0. 12%/3.05% ±0. 13% (10 s/20 s), and 3.03% ±0.05%/3. 11% ±0.07% (10 s/20 s), respectively. No significant difference existed among polymerization shrinkage of composites cured by the three light-curing modes (P>0. 05). The hardness of composites cured by high intensity, low intensity and soft-start curing mode was; (36.82 ±4.45) Mpa/(47.58 ±3.16) Mpa (10 s/20 s), (32.30 ±1.33) Mpa/(41.60±1.83) Mpa (10 s/20 s), and (34. 56 ± 1. 38) Mpa/(44. 62 ±2. 13) Mpa (10 s/20 s) , respectively. There existed significant difference among hardness of composites cured by the three light-curing modes ( P<0. 05 ). Polymerization shrinkage was correlated with energy density ( r = -0. 363, P = 0. 018). Surface hardness was also correlated with energy density (r = -0. 890, P < 0.001 ). Conclusion:It would be better to use high intensity curing mode to improve the physical properties of restorations. In order to keep the physical properties of composites, it is necessary to prolong the curing time using soft-start/low intensity curing modes to increase the energy density.%目的:研究光固化模式对复合树脂聚合收缩率和表面硬度的影响,探讨这些因素的影响对临床工作的指导意义.方法:研究使用填料含量为76%(质量分数)的

  3. 光固化冠桥复合树脂强化作用的实验研究%Experimental Study on the Reinforced Effect of Light-Curing Composite Resins Used for Crowns and Bridges

    Institute of Scientific and Technical Information of China (English)

    孙健; 张建中

    2001-01-01

    Objective To evaluate the reinforced effect of the light-curingcomposite resins used for crowns and bridges. Method Three light-curing composite resins which were used for crowns and bridges were chosen, and three polyester fiber sieves and three stainless steel sieves in different mesh were used as the additional reinforced materials.Compressive strength and three point flexural strength of test bars made of those materials were evaluated. The reinforced bridges with special fibers were used as control groups.Result (1)There was significant increase in the stainless steel sieves groups. Nevertheless, there was some decrease after use of the polyester fibers as the additional reinforced material. (2)The increase of the reinforced crowns was especially obvious. (3)Among the three resins, the property of Targis was better than that of Arglass and Solidex.Conclusion The properties of the whole composite material were closely correlated with the additional reinforced materials, the resistance to compression of the sieves are better than its resistance to bend.%目的 探讨光固化冠桥复合树脂的强化效果。方法 选择3种光固化冠桥树脂,3种不同目数的涤纶和3种不同目数的不锈钢筛网作外加强。制作试件及冠桥,并与专用纤维网加强桥相比,测定抗压、3点抗弯强度。结果 ⑴不锈钢丝网增强效果明显,涤纶丝网无强化效果;⑵冠的加强效果尤为明显;⑶Targis的性能好于Artglss和Solidex。结论 复合材料的性能与外加强材料密切相关,金属网状结构对压缩的耐受性优于对屈曲的耐受性。

  4. Effect of light power density on the anti-aging property ot light-cure composite resin%光功率密度对光固化复合树脂耐老化性能的影响

    Institute of Scientific and Technical Information of China (English)

    韩冰; 王晓燕; 高学军

    2011-01-01

    目的:比较不同引发光功率密度对光周化复合树脂耐老化性能的影响.方法:选择光功率密度不同的3种引发固化光模式:(1)模式A,低光功率密度500 mW/cm2,22 s;(2)模式B,高光功率密度1100 mW/cm2,10 s;(3)模式C,渐强式光功率密度,0~650 mW/cm2,5 s,1 100 mW/cm2,8.5 s.3种模式总能量密度均为11 J/cm2.用不同光引发模式同化复合树脂样本,随机分为4绀(n=15),其中3组进行老化,分别浸泡于乙醇中24 h、7 d和30 d.对照组为纯水浸泡24 h.使用显微硬度仪测量样本表面维氏(VHN)硬度.同时使用Acuvol聚合收缩仪测定不同光功率密度引发光固化复合树脂的聚合收缩率(n=7).结果:不同引发光功率密度同化复合树脂的表面硬度为模式A 44.26±6.16,模式B 42.31±2.33,模式C 45.60±2.76.乙醇老化24 h后,树脂表面硬度均有明显下降(P0.05).乙醇老化30 d后,样本表面硬度不再继续降低,与7 d组相比差异无统计学意义(P>0.05),表面硬度值为模式A 28.53±0.86,模式B 28.55±1.53,模式C 29.08±1.60.不同光功率密度模式固化复合树脂的聚合收缩率分别为模式A2.67%±0.28%,模式B 2.76%±0.29%,模式C2.73%±0.06%,差异无统计学意义(P>0.05).结论:光能量密度一致时,引发光功率密度对光固化复合树脂聚合收缩无显著影响,对树脂耐老化性能的影响与老化作用时间相关.%Objective:The purpose of this study was to investigate the effect of light power density on anti-aging property of composite resins. Methods: Three light curing modes with different power density (1. Mode A: low power density, 500 mW/cm2 for 22 s; 2. Mode B: high power density, 1 100 mW/ cm2 for 10 s; 3. Mode C: gradually enhanced power density, 0 ~650 mW/cm2 for 5 s + 1 100 mW/cm2 for 8.5 s) were used. The total energy density of these modes was all 11 J/cm2. Composite resin specimens were cured with three light curing modes respectively and divided into 4 groups randomly ( n= 15 ).Three

  5. The curative effect observation of super adhesive bonding of light cured composite resin inlay in the repair of deciduous teeth Ⅱ complex cavities%超级黏接剂黏接光固化复合树脂嵌体在修复乳牙Ⅱ类复面洞型的疗效观察

    Institute of Scientific and Technical Information of China (English)

    辜赵娜

    2015-01-01

    目的:观察超级黏接剂黏接材料黏接复合树脂嵌体在修复乳牙Ⅱ类洞型的临床疗效。方法:收治乳牙Ⅱ类洞型患者18例,采用超级黏接剂黏接材料黏接复合树脂嵌体进行修复治疗,观察临床效果。结果:经过随访观察,用超级黏接剂黏接材料黏接光固化复合树脂嵌体在口腔无脱落,嵌体边缘继发龋发生率4.8%。结论:使用超级黏接剂材料黏接光固化复合树脂嵌体具有很好防止脱落和防止继发龋的效果。%Objective:To explore the curative effect observation of super adhesive bonding of light cured composite resin inlay in the repair of deciduous teeth Ⅱ complex cavities.Methods:18 patients with deciduous teeth Ⅱ complex cavities were selected. They were treated by super adhesive bonding of light cured composite resin inlay.We observed the clinical effect.Results:After follow-up observation,with super adhesive bonding of light cured composite resin inlay,there was no shedding in oral,and secondary caries incidence at inlay edge was 4.8%.Conclusion:Using super adhesive bonding of light cured composite resin inlay was good to prevent the shedding and prevent the incidence of secondary caries.

  6. Translucency,opalescence and fluorescence properties of six light-cured resin composites%6种光固化复合树脂的半透性、乳光性及荧光性研究

    Institute of Scientific and Technical Information of China (English)

    杨琳; 陈豆豆; 张君平; 李继遥

    2016-01-01

    目的:体外测定6种光固化复合树脂的半透性、乳光性及荧光性参数。方法:将6种光固化复合树脂,包括 Filtek Supreme XT-YT(XT)、Filtek Supreme XT-A3B(3M)、Clearfil Majesty-A3(MJ)、Gradia Direct-A3(GC)、Venus-A3(VE)、Cha-risma Diamond-A3(CA)制备成直径9 mm,厚度为2.0 mm 的盘状树脂块。采用 PR-650光谱扫描色度仪,测量并计算样本半透性参数(TP 值)、乳光参数(OP 值)及荧光参数(FL 值),并绘制荧光反射曲线。结果:TP 值,除 XT 与 MJ 外,余下树脂均在天然牙范围内;OP 值,仅 XT 在天然牙牙釉质范围内;FL 值,XT 最接近天然牙;GC、MJ、VE、CA 的荧光峰值波长在天然牙范围内,峰值均高于天然牙;样本的 TP、OP 正相关(r =0.85,P <0.05),而 TP 与 FL、OP 与 FL 的相关均无统计学意义(P>0.05)。结论:现常用树脂能较好模拟天然牙光学特性,但在乳光性方面与天然牙尚有差异。%Objective:To evaluate the translucency,opalescence and fluorescence reflection of 6 light-cured resin composites. Methods:Disks of 6 resin composites including Filtek Supreme XT-YT(XT),Filtek Supreme XT-A3B(3M),Clearfil Majesty-A3 (MJ),Gradia Direct-A3(GC),Venus-A3(VE)and Charisma Diamond-A3(CA)were prepared in the diameter of 9 mm with the thickness 2.0 mm.PR-650 spectral scanning colorimeter was used to measure and caculate translucency parameters(TP),opal-escence parameter(OP)and fluorescence reflection(FL)and to draw the fluorescence reflection curves.Results:Except XT and MJ,TP value of other resin composites were in the range of natural tooth.Only OP value of XT was in the range of natural tooth en-amel.FL value of XT was close to that of natural tooth dentin.Fluorescent peak wavelength of GC,MJ,VE and CA were in the range of natural tooth,but fluorescent peak height was higher than that of natual tooth.TP was positively correlated with OP(r =0

  7. Effect of different light-curing devices and aging procedures on composite knoop microhardness

    Directory of Open Access Journals (Sweden)

    Fernanda Regina Voltarelli

    2009-12-01

    Full Text Available The aim of this study was to evaluate the effect of light-curing devices (Halogen/HAL, Light Emitting Diodes/LED, Argon Laser/LAS and Plasma Arc/PAC and aging procedures (Mechanical Cycling/MC, Thermal Cycling/TC, Storage/S, MC+TC and MC+TC+S on the micro-hardness of bottom/B and top/T surfaces of 2-mm-high composite resin cylinders. The Knoop microhardness test (25 g, 20 s on both B and T was performed before and after each aging procedure. For B and T, before aging procedures, PAC showed reduced polymerization effectiveness when compared with HAL. In the T, after TC, PAC and LAS had also showed reduced polymerization effectiveness when compared to HAL and LED. For all light-curing devices, MC+TC+S and S affected the Knoop microhardness values. In the B, no difference could be observed among the aging procedures for PAC. From all light-curing units, PAC may have rendered composites of reduced quality and the storage aging procedures were the most harmful to the polymer hardness.

  8. Influence of composite restorative materials and light-curing units on diametrical tensile strength.

    Science.gov (United States)

    Tolosa, Maria Cecília Caldas Giorgi; Paulillo, Luís Alexandre Maffei Sartini; Giannini, Marcelo; Santos, Alex José Souza dos; Dias, Carlos Tadeu dos Santos

    2005-01-01

    The aim of this study was to evaluate the diametrical tensile strength (DTS) of three light-curing photo-activated composites with two different light curing units (LCU). Three types of dental restorative composites were used in this study: micro filled A110 (3M Espe); P60 (3M Espe) for posterior restorations, and micro-hybrid Charisma (Heraeus-Kulzer). The two LCUs were: halogen light (HAL) (Degulux, Degussa) and blue light emitting diode (LED) (Ultrablue, DMC). Resin composite specimens were inserted incrementally into a Teflon split mold measuring 3 mm in depth and 6 mm in internal diameter, and cured using either LCU (n = 10). Specimens were placed into a dark bottle containing distilled water at 37 degrees C for 7 days. DTS tests were performed in a Universal Testing Machine (0.5 mm/min). Data were submitted to two-way ANOVA and Tukey's test. Results were (MPa): A110/HAL: 276.50 +/- 62.94a; A110/LED: 306.01 +/- 65.16a; P60/HAL: 568.29 +/- 60.77b and P60/LED: 543.01 +/- 83.65b; Charisma/HAL: 430.94 +/- 67.28c; Charisma/LED: 435.52 +/- 105.12c. Results suggested that no significant difference in DTS was obtained with LCUs for the same composite. However, resin composite restorative materials presented different DTS.

  9. Comparison of Shear Bond Strength and Estimation of Adhesive Remnant Index between Light-cure Composite and Dual-cure Composite: An in vitro Study.

    Science.gov (United States)

    Verma, Geeta; Trehan, Mridula; Sharma, Sunil

    2013-09-01

    To measure and compare the shear bond strength and adhesive remnant index of light-cure composite. (Enlight, Ormco.) and dual-cure composite (Phase II dual cure, Reliance Ortho). Sixty extracted human premolar teeth were divided into two groups: group I (blue): conventional light cure composite resin. (Enlight, Ormco.) and group II (green): dual cure composite resin. (Phase II dual cure, Reliance Ortho.) with 30 teeth in each group. These samples were tested on the universal testing machine to measure the shear bond strength. Student t-test showed that the mean shear bond strength of the conventional light cure group (8.54 MPa - 10.42 MPa) was significantly lower than dual cure group (10.45 MPa -12.17 MPa). These findings indicate that the shear bond strength of dual-cure composite resin (Phase II dual cure, Reliance Ortho) is comparatively higher than conventional light-cure composite resin (Enlight, Ormco). In the majority of the samples, adhesive remnant index (ARI) scores were 4 and 5 in both the groups whereas score 1 is attained by the least number of samples in both the groups. How to cite this article: Verma G, Trehan M, Sharma S. Comparison of Shear Bond Strength and Estimation of Adhesive Remnant Index between Light-cure Composite and Dual-cure Composite: An in vitro Study. Int J Clin Pediatr Dent 2013;6(3):166-170.

  10. Avaliação in vitro da microinfiltração em cavidades classe II de molares decíduos, restaurados com resina composta auto e fotopolimerizável Analysis in vitro of microleaking in class II cavities of deciduous molars, restored with auto and light-cured composite resin

    Directory of Open Access Journals (Sweden)

    Alessandro Leite CAVALCANTI

    1999-04-01

    Full Text Available Estudou-se a microinfiltração marginal presente na interface da parede gengival de cavidades classe II em molares decíduos, restaurados com resina composta (auto e fotopolimerizável, através da penetração de uma solução corante. Os preparos cavitários apresentavam a parede gengival em esmalte e foram restaurados segundo 4 diferentes técnicas: 1 resina composta fotopolimerizável; 2 resina composta autopolimerizável; 3 resina composta auto e fotopolimerizável; e 4 ionômero de vidro/resina composta. Após a análise estatística dos resultados, concluiu-se que todos os grupos apresentaram microinfiltração em graus variados; todavia, os grupos 2, 3 e 4 apresentaram os menores graus de infiltração.The purpose of this study was the evaluation in vitro of marginal microleaking, present on gum’s edges of class II cavities of deciduous molars, restored with composite resin (auto and light-cured, with the use of a staining solution to verify the leaking. The prepared cavities presented enamel on gum’s edges and were restored according to four different techniques: 1 light-cured composite resin; 2 auto-cured composite resin; 3 mixed technique (auto and light-cured composite resin; and 4 glass-ionomer/composite resin. After the statistical analysis of the results, it was concluded that all the groups presented microleaking, in variable degrees. However, groups 2, 3 and 4 presented the smallest levels of leaking.

  11. 纳米复合树脂和光固化复合树脂材料用于前牙美容修复的效果比较%Effect of Nano-Composite Resin Material and Light-Cured Composite Resin Material on Cosmetic Restoration of Anterior Teeth

    Institute of Scientific and Technical Information of China (English)

    王玫

    2014-01-01

    目的:比较纳米复合树脂材料和光固化复合树脂材料用于前牙美容修复的效果。方法选择接受前牙美容修复的患者100例作为研究对象,分别使用光固化复合树脂材料及纳米复合树脂材料,比较治疗后牙齿敏感发生率及自觉疼痛评分差异。结果观察组治疗后1 d、1周、1个月牙齿敏感发生率分别为8.00%,6.00%,4.00%,均明显低于对照组( P﹤0.05);平均疼痛评分为(2.63±0.72)分,并发症发生率为22.22%,均明显低于对照组( P﹤0.05);优良率为88.00%,满意度为92.00%,均明显高于对照组( P﹤0.05)。结论纳米复合树脂材料用于患者前牙美容修复可有效降低近期牙齿敏感发生率,减轻自觉疼痛感受,优于光固化复合树脂材料。%Objective To compare the effect of the nano-composite resin material and the light-cured composite resin material on cosmetic restoration of anterior teeth. Methods The 100 patients receiving cosmetic restoration of anterior teeth were selected as the research subjects and used the light-cured composite resin materials and the nano-composite resin materials respectively. The occur-rence rates of the tooth sensitivity and the perceived pain scores after therapy were compared between the two kinds of materi-als. Results The occurrence rates of the teeth sensitive on 1 d' 1 week' 1 month after treatment in the observation group were 8. 00%' 6. 00% and 4. 00% respectively' which were significantly lower than those in the control group ( P﹤0. 05 ) . The average pain scores in the observation group were ( 2. 63 ± 0. 72 ) and the occurrence rate of complications was 22. 22%' which were significantly lower than those in the control group ( P﹤0. 05 ) . The excellent rate in the observation group was 88. 00% and the satisfaction was 92. 00%' which were significantly higher than those in the control group( P﹤0. 05). Conclusion Nano-composite resin can effectively

  12. Analysis of clinical efficacy of light-cured composite resin and GC FUJI Ⅸglass ionomer in dental caries fill- ing%光固化复合树脂和 GC FUJI Ⅸ玻璃离子充填龋齿临床疗效分析

    Institute of Scientific and Technical Information of China (English)

    周丽

    2014-01-01

    Objective To observe the clinical curative effect of light cured composite resin and GC FUJI Ⅸglass ionomer in filling dental caries .Methods One hundred and eight patients with 326 caries teeth were randomly divided into light cured resin group (54 cases, 150 teeth) and GC FUJI Ⅸ group(54 cases, 176 teeth) and were treated respectively by light cured composite resin and GC FUJI Ⅸglass ionomer for restorations of dental caries .One year after filling , the clinical efficacy was compared between the two groups .Results The restoration success rate of GC FUJIⅨgroup(97.2%) was higher than that of light cured resin group (87.3%)(P<0.01).Conclusion The efficacy of deep caries filling of GC FUJI Ⅸglass ionomer is better than that of light cured composite resin .%目的:观察光固化复合树脂和GC FUJIⅨ玻璃离子两种材料充填龋齿的临床疗效。方法将108例(326颗患牙)随机分为光固化树脂组(54例150颗)和GC FUJI Ⅸ组(54例176颗),光固化树脂组采用光固化复合树脂材料充填修复,GC FUJIⅨ组采用GC FUJIⅨ玻璃离子材料充填修复,随访观察一年,比较两组的临床疗效。结果采用GC FUJI Ⅸ玻璃离子材料充填修复成功率(97.2%)高于光固化复合树脂组(87.3%)(P<0.01)。结论 GC FUJI Ⅸ玻璃离子充填深龋疗效优于光固化复合树脂。

  13. Degree of Conversion of a Resin Cement Light-Cured Through Ceramic Veneers of Different Thicknesses and Types

    OpenAIRE

    Runnacles,Patrício; Correr, Gisele Maria; Flares BARATTO FILHO; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

    2014-01-01

    During the cementation of ceramic veneers the polymerization of resin cements may be jeopardized if the ceramics attenuate the irradiance of the light-curing device. The aim of this study was to evaluate the effect of different types and thicknesses of ceramic veneers on the degree of conversion of a light-cured resin-based cement (RelyX Veneer). The cement was light-cured after interposing ceramic veneers [IPS InLine, IPS Empress Esthetic, IPS e.max LT (low translucency) and IPS e.max HT (hi...

  14. Hardness of a bleaching-shade resin composite polymerized with different light-curing sources Microdureza de uma resina composta para dentes clareados polimerizada com diferentes fontes de luz fotoativadora

    Directory of Open Access Journals (Sweden)

    Giovana Mongruel Gomes

    2006-12-01

    Full Text Available The microhardness of a bleaching-shade resin composite polymerized with different light-curing units was evaluated. Composite samples (3M ESPE Filtek Supreme were applied to brass rings (2 mm in thickness, 5 mm in diameter. Three commercial LED lights were used to polymerize the specimens and the results were compared to those of a conventional halogen light. The light sources used in the present study were: Demetron Optilux 401 (QTH, 3M ESPE Elipar FreeLight (LED 1; Kerr L.E.Demetron I (LED 2, and ColtoluxLED lights (LED 3. The microhardness of the top and bottom surfaces was assessed with a digital Vickers hardness-measuring instrument, under load. At the bottom surface, no significant difference among the light sources was observed (two-way ANOVA. At the top surface, the QTH light source presented significantly higher hardness values compared to the values observed when LED 1 and LED 3 were used. There were no significant differences between the QTH and LED 2 light sources. Significantly higher hardness values were also found at the top surface when compared to the values observed at the bottom surface. The power density of the polymerization light sources seemed to be responsible for the observed resin composite hardness, not their irradiance.Avaliou-se a microdureza de uma resina composta para dentes clareados fotoativada com diferentes fontes de luz fotoativadora. Espécimes de resina composta (3M ESPE Filtek Supreme foram aplicados a cilindros de latão (2 mm de espessura, 5 mm de diâmetro. Três fontes comerciais de luz LED foram utilizadas para polimerizar os espécimes e os resultados foram comparados aos obtidos utilizando-se uma fonte de luz halógena convencional. As fontes de luz utilizadas no presente estudo foram: Demetron Optilux 401 (QTH, 3M ESPE Elipar FreeLight (LED 1; Kerr L.E.Demetron I (LED 2, e ColtoluxLED lights (LED 3. A microdureza das superfícies topo e base foram avaliadas com um microdurômetro digital (Dureza

  15. Polymerization contraction and conversion of light-curing BisGMA-based methacrylate resins.

    Science.gov (United States)

    Venhoven, B A; de Gee, A J; Davidson, C L

    1993-09-01

    The aim of this study was to investigate the polymerization contraction and the conversion of light-curing methacrylate resins based on bisphenol-A bis(2-hydroxypropyl)methacrylate (BisGMA) diluted with triethylene glycol dimethyacrylate (TEGDMA), methyl methacrylate (MMA), hydroxypropyl methacrylate (HPMA) or (+/-)-2-ethylhexyl methacrylate (EHMA). The contraction measurements were carried out with a linometer, a simple device to determine true linear polymerization contraction of liquid monomers at ambient temperature. The contraction increased with the amount of diluting monomer. The estimated conversion of the BisGMA-TEGDMA, calculated using the contraction, is consistent with literature values. The BisGMA-HPMA mixtures showed high conversions at moderate contraction.

  16. Evaluation of wear rate of dental composites polymerized by halogen or LED light curing units

    Directory of Open Access Journals (Sweden)

    Alaghehmand H.

    2006-08-01

    Full Text Available Background and Aim: Sufficient polymerization is a critical factor to obtain optimum physical properties and clinical efficacy of resin restorations. The aim of this study was to evaluate wear rates of composite resins polymerized by two different systems Light Emitting Diodes (LED to and Halogen lamps. Materials and Methods: In this laboratory study, 20 specimens of A3 Tetric Ceram composite were placed in brass molds of 2*10*10 mm dimensions and cured for 40 seconds with 1 mm distance from surface. 10 specimens were cured with LED and the other 10 were cured with Halogen unit. A device with the ability to apply force was developed in order to test the wear of composites. After storage in distilled water for 10 days, the specimens were placed in the wear testing machine. A chrome cobalt stylus with 1.12 mm diameter was applied against the specimens surfaces with a load of 2 kg. The weight of each samples before and after 5000, 10000, 20000, 40000, 80000 and 120000 cycles was measured using an electronic balance with precision of 10-4 grams. Data were analyzed using t test and paired t test. P0.05. Conclusion: Based on the results of this study, LED and halogen light curing units resulted in a similar wear rate in composite resin restorations.

  17. Observation of Clinical Therapeutic Effect of Combination of Glass Gonomer Gement and Light Cured Composite Resin on Restoring Wedge Shaped Defect%两种材料联合修复牙齿楔状缺损的临床疗效观察

    Institute of Scientific and Technical Information of China (English)

    戴晓枫

    2012-01-01

    Objective To evaluate clinical therapeutic effect of combination of glass ionomer cement and light cured composite resin on restoring wedge shaped defect. Methods 110 teeth with wedge shaped defects in treatment group were filled and repaired with glass ionomer cement. The light cured composite resin was used to repair the teeth permanently after 24 hours. The other two control groups were treated with glass ionomer cement and light cured composite resin respectively. The treatment results and cure rates were compared between the three groups after one year follow-up. Results The cure rates of treatment group and two control groups were 98.61%, 77.85%, 77.46% respectively. The difference between treatment group and control groups was significant (p<0.01). Conclusion The combination of glass ionomer cement and light cured composite resin is a better method to restore the wedge shaped defect.%目的探讨玻璃离子水门汀联合光固化复合树脂充填修复牙齿楔状缺损的临床疗效.方法对110例楔状缺损患牙采用玻璃离子水门汀常规充填雕刻成形,然后行光固化复合树脂永久修复.对照组分别用玻璃离子、光固化复合树脂.随访一年后比较3组修复楔状缺损治愈率.结果两种材料联合修复牙齿楔状缺损的治愈率98.61%,对照组的治愈率77.85%和77.46%;两组有显著差异(P<0.01).结论两种材料联合修复牙齿楔状缺损技术是理想方法之一.

  18. Observation of Effect onFilling of 50 CasesWedge Shaped DefectTeeth by Light Cured Composite Resin and Glass Ionomer Cement%光固化复合树脂、玻璃离子水门汀填充牙楔状缺损50例的疗效观察

    Institute of Scientific and Technical Information of China (English)

    马勇

    2016-01-01

    Objective To investigate the clinical efficacyonfilling of 50 caseswedge shaped defectteeth by light cured composite resin and glass ionomer cement.Methods50 cases (186 teeth) with wedge shaped defect in our hospital were selected.They were randomly divided into light cured composite resin and glass ionomer cement joint repair group (observation group),62 teeth, light cured composite resin repair group (control group 1),58 teeth, glass ionomer cement group (control group 2),66 teeth, therapeutic effect of three groups of patients were compared.ResultsAfter 2 years of observation, the success rate of observation group was significantly higher than that of control group 1 and control group 2, the difference was statistically significant (P0.05).ConclusionIt canobtain good therapeutic effect thatwedge shaped defectteeth was repaired by light cured composite resin and glass ionomer cement. This method is worthy to be popularized and applied in clinical practice.%目的:探讨光固化复合树脂联合玻璃离子水门汀填充牙楔状缺损的临床疗效。方法选取本院门诊收治的50例(共186颗)牙楔状缺损患者,随机将其分为光固化复合树脂与玻璃离子水门汀联合修复组(观察组),共62颗,光固化复合树脂修复组(对照1组),共58颗,玻璃离子水门汀修复组(对照2组),共66颗,对三组患者的治疗效果进行比较。结果经2年的修复观察,观察组的修复成功率明显高于对照1组和对照2组,差异具有统计学意义(P0.05)。结论光固化复合树脂联合玻璃离子水门汀填充牙楔状缺损能取得良好的治疗效果,值得在临床推广与应用。

  19. Effect of preheating and light-curing unit on physicochemical properties of a bulk fill composite

    Directory of Open Access Journals (Sweden)

    Theobaldo JD

    2017-05-01

    Full Text Available Jéssica Dias Theobaldo,1 Flávio Henrique Baggio Aguiar,1 Núbia Inocencya Pavesi Pini,2 Débora Alves Nunes Leite Lima,1 Priscila Christiane Suzy Liporoni,3 Anderson Catelan3 1Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, 2Ingá University Center, Maringá, 3Departament of Dentistry, University of Taubaté, Taubaté, Brazil Objective: The aim of this study is to evaluate the effect of composite preheating and polymerization mode on degree of conversion (DC, microhardness (KHN, plasticization (P, and depth of polymerization (DP of a bulk fill composite.Methods: Forty disc-shaped samples (n = 5 of a bulk fill composite were prepared (5 × 4 mm thick and randomly divided into 4 groups according to light-curing unit (quartz–tungsten–halogen [QTH] or light-emitting diode [LED] and preheating temperature (23 or 54 °C. A control group was prepared with a flowable composite at room temperature. DC was determined using a Fourier transform infrared spectrometer, KHN was measured with a Knoop indenter, P was evaluated by percentage reduction of hardness after 24 h of ethanol storage, and DP was obtained by bottom/top ratio. Data were statistically analyzed by analysis of variance and Tukey’s test (α = 0.05.Results: Regardless of light-curing, the highest preheating temperature increased DC compared to room temperature on bottom surface. LED showed a higher DC compared to QTH. Overall, DC was higher on top surface than bottom. KHN, P, and DP were not affected by curing mode and temperature, and flowable composite showed similar KHN, and lower DC and P, compared to bulk fill.Conclusion: Composite preheating increased the polymerization degree of 4-mm-increment bulk fill, but it led to a higher plasticization compared to the conventional flowable composite evaluated. Keywords: composite resins, physicochemical phenomena, polymerization, hardness, heating

  20. Effectiveness of composite resin polymerization using light-emitting diodes (LEDs or halogen-based light-curing units Efetividade de polimerização de uma resina composta fotopolimerizada por diodos emissores de luz (LEDs ou luz halógena

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    Bianca Micali

    2004-09-01

    Full Text Available The clinical performance of composite resins is greatly influenced by the quality of the light-curing unit used. The aim of this study was to compare the efficiency of a commercial light-emitting diode (LED with that of a halogen-based light-curing unit by means of dye penetration of a micro hybrid composite resin. The composite resin evaluated was Filtek Z250 (3M Dental. The composite was filled into acrylic moulds that were randomly polymerized for 40 seconds by each of the light-emitting systems: light-emitting diode Ultraled (Dabi Atlante or halogen light Degulux (Degussa Hüls curing units. Immediately after polymerization, each specimen was individually immersed in 1 ml of 2% methylene blue solution at 37°C ± 2°C. After 24 hours, the specimens were rinsed under running distilled water for 1 minute and stored at 37°C ± 2°C at relative humidity for 24 hours. The composite resins were removed from the moulds and individually triturated before being immersed in new test tubes containing 1 ml of absolute alcohol for 24 hours. The solutions were filtered and centrifuged for 3 minutes at 4,000 rpm and the supernatant was used to determine absorbance in a spectrophotometer at 590 nm. To verify the differences between groups polymerized by LED or halogen light t-test was applied. No significant differences were found between composite resins light-cured by LED or halogen light-curing unit (p > 0.05. The commercially LED-based light-curing unit is as effective to polymerize hybrid composite resins as the halogen-based unit.A longevidade clínica das resinas compostas é grandemente influenciada pela qualidade do aparelho fotopolimerizador utilizado. O objetivo deste trabalho foi comparar a eficácia de um aparelho fotopolimerizador de diodos emissores de luz e a de um de luz halógena através do grau de penetração de um corante em uma resina composta micro-híbrida. A resina composta utilizada (Filtek Z250/3M Dental foi inserida em matrizes

  1. Degree of conversion of a resin cement light-cured through ceramic veneers of different thicknesses and types.

    Science.gov (United States)

    Runnacles, Patrício; Correr, Gisele Maria; Baratto Filho, Flares; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

    2014-01-01

    During the cementation of ceramic veneers the polymerization of resin cements may be jeopardized if the ceramics attenuate the irradiance of the light-curing device. The aim of this study was to evaluate the effect of different types and thicknesses of ceramic veneers on the degree of conversion of a light-cured resin-based cement (RelyX Veneer). The cement was light-cured after interposing ceramic veneers [IPS InLine, IPS Empress Esthetic, IPS e.max LT (low translucency) and IPS e.max HT (high translucency) - Ivoclar Vivadent] of four thicknesses (0.5 mm, 1.0 mm, 1.5 mm and 2.0 mm). As control, the cement was light-cured without interposition of ceramics. The degree of conversion was evaluated by FTIR spectroscopy (n=5). Data were analyzed with one-way ANOVA and Tukey's test (α=0.05). Significant differences were observed among groups (p0.05). Among 1.5-mm-thick veneers, IPS e.max LT was the only one that showed different results from the control (pveneers were able to produce cements with degrees of conversion similar to the control (p>0.05). The degree of conversion of the evaluated light-cured resin cement depends on the thickness and type of ceramics employed when veneers thicker than 1.5 mm are cemented.

  2. 光固化复合树脂前体与超级粘接剂结合治疗乳牙洞型的临床疗效研究%Research on Light Curing Composite Resin Precursor Combined with Super Adhesive for Primary Cavity

    Institute of Scientific and Technical Information of China (English)

    辜赵娜

    2016-01-01

    Objective: To observe the clinical efficacy of super-BondC&B bonding light-cured compos-ite combined with light curing composite resin precursor on treatment of primary cavity and super adhesive. Method: 150 deciduous molar teeth caries after preparing into Ⅱ type complex surface hole type were ran-domly divided into two groups, the control group and observation group, 75 teeth in each group, both groups used light-curing resin inlay fill, the control group used ordinary adhesive, observation group used super-BondC&B. Results: Within the same time the bonding degree of observation group was better than the control group. According to the indicators re-checked 1 year later, the success rate control group observation group was 41.33% and 86.67%, which was higher observation group than the control group. The difference of the two groups data has statistical significance (P<0.05). Patients’ satisfaction survey of observation group was better than the control group. Conclusion: Using super-BondC&B bonding of light-cured composite resin in-lay in the repair teeth class Ⅱ when facing hole type success rate high, the effect is good. It should be the ma-terial of choice for he bonding light-cured composite resin inlay.%目的::观察超级粘结剂(super-BondC&B)粘结光固化复合树脂嵌体在修复乳牙Ⅱ类复面洞型的疗效。方法:150颗乳磨牙龋齿经过去龋备成Ⅱ类复面洞型后随机分为两组,对照组和观察组各75颗,两组都使用光固化树脂嵌体填充,对照组使用普通粘接剂,观察组使用 super-BondC&B。结果:相同时间内粘接程度观察组好于对照组。1年后复查时,对照组成功率为41.33%,观察组成功率为86.67%,观察组高于对照组,两组数据比较差异具有统计学意义(P <0.05)。在患者满意度调查中观察组的评价也好于对照组。结论:使用超级粘结剂( super-BondC&B)粘接的光固化复合树脂嵌体在修复乳牙Ⅱ

  3. 用布喇格光纤光栅传感器测定口腔复合树脂材料光固化收缩与温度演化特性%Evaluation of Shrinkage Stress and Exotherm during Light-curing of Dental Resin Composites

    Institute of Scientific and Technical Information of China (English)

    刘林; 叶志清; 饶春芳; 胡友德; 匡芬; 王燕

    2012-01-01

    复合树脂材料已成为重要的牙齿美容修复材料.本文利用两种布喇格光纤光栅传感器测定了口腔复合树脂材料在光固化过程中的收缩与温度演化特性.一种为普通的光纤布喇格光栅,另一种为经过了化学镀镍的光纤布喇格光栅,同时埋入复合树脂样品中,用光照射使其固化,测得光纤布喇格光栅在固化过程中温度和应力随时间的演化曲线.实验结果表明,在光固化过程中,因为聚合反应,树脂产生了强烈的收缩应力和温度变化,掌握复合树脂的光固化收缩特性和温度变化特性时不断改良材料性能以及优化口腔材料的治疗效果具有实际意义.%Light-cured composite resin is an important material in densitry for beauty and restoration. Fiber Bragg gratings (FBG) is used to determine composite resin shrinkage during the light-curing. Because FBGs are both sensitivity to temperature and strain, two different kinds of FBGs were used to calculate the temperature and strain respectively. One of the FBG was bare, and the other was chemical plated FBG, both of which were embedded in one sample of resin simultaneously. LED light source was used for light curing. Real time changes of temperature and shrinkage strain were gained. The experiments showed that the resin expressed strong shrinkage strain and temperature variation because of the polymerization reaction during the curing. The results are helpful for understanding the shrinkage and temperature change of the materials and improving more prefecable treatment effect.

  4. Effect of light curing tip distance and resin shade on microhardness of a hybrid resin composite Efeito da distância da ponta do aparelho de fotoativação e da cor na microdureza superficial de um compósito híbrido

    Directory of Open Access Journals (Sweden)

    Flávio Henrique Baggio Aguiar

    2005-12-01

    Full Text Available Resin composite shades and resin composite polymerization performed with a distanced light tip are factors that can affect polymerization effectiveness. Thisin vitro study aimed to evaluate the influence of curing tip distance and resin shade on the microhardness of a hybrid resin composite (Z250 - 3M ESPE. Forty-five resin composite specimens were randomly prepared and divided into nine experimental groups (n = 5: three curing tip distances (2 mm, 4 mm, and 8 mm and three resin shades (A1, A3.5, and C2. All samples were polymerized with a continuous output at 550 mW/cm². After 24 hours, Knoop microhardness measurements were obtained on the top and bottom surfaces of the sample, with a load of 25 grams for 10 seconds. Five indentations were performed on each surface of each sample. Results showed that bottom surface samples light-cured at 2 mm and 4 mm presented significantly higher hardness values than samples light-cured at 8 mm. The resin shade A1 presented higher hardness values and was statistically different from C2. The resin shade A3.5 did not present statistical differences from A1 and C2. For the top surface, there were no statistical differences among the curing tip distances. For all experimental conditions, the top surface showed higher hardness values than the bottom surface. It was concluded that light curing tip distance and resin shade are important factors to be considered for obtaining adequate polymerization.A cor do compósito e a polimerização realizada com a ponta do aparelho de fotoativação distante da superfície do compósito são fatores que podem afetar a efetividade de polimerização. Assim, o objetivo deste estudo in vitro foi avaliar a influência desses fatores na microdureza superficial de um compósito híbrido (Z250 - 3M ESPE. Quarenta e cinco espécimes de compósito foram aleatoriamente preparados de acordo com os nove grupos experimentais (n = 5: três distâncias de fotoativação (2 mm, 4 mm e 8 mm e

  5. Shrinkage Characteristics of Experimental Polymer Containing Composites under Controlled Light Curing Modes

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    Alain Pefferkorn

    2012-01-01

    Full Text Available The adsorption of polymethylmethacrylate polymer of different molecular weight at the aerosil/ethyleneglycol- or 1,3 butanediol-dimethacrylate interfaces was determined to provide microstructured networks. Their structural characteristics were determined to be controlled by the amount of polymer initially supplied to the system. The sediment (the settled phase characteristics, determined as a function of the polymer concentration and the rate of the polymerization shrinkage determined for composite resins, obtained by extrusion of the sediment after centrifugation, were found to be correlated. The specific role of the adsorbed polymer was found to be differently perturbed with the supplementary supply of dimethacrylate based monomer additives. Particularly, the bisphenol A dimethacrylate that generated crystals within the sediment was found to impede the shrinkage along the crystal lateral faces and strongly limit the shrinkage along its basal faces. Addition of ethyleneglycol- or polyethylene-glycoldimethacrylate monomers was determined to modify the sedimentation characteristics of the aerosil suspension and the shrinkage properties of the composites. Finally, the effects of stepwise light curing methods with prolonged lighting-off periods were investigated and found to modify the development and the final values of the composite shrinkage.

  6. Influence of curing time, overlay material and thickness on three light-curing composites used for luting indirect composite restorations.

    Science.gov (United States)

    D'Arcangelo, Camillo; De Angelis, Francesco; Vadini, Mirco; Carluccio, Fabio; Vitalone, Laura Merla; D'Amario, Maurizio

    2012-08-01

    To assess the microhardness of three resin composites employed in the adhesive luting of indirect composite restorations and examine the influence of the overlay material and thickness as well as the curing time on polymerization rate. Three commercially available resin composites were selected: Enamel Plus HRI (Micerium) (ENA), Saremco ELS (Saremco Dental) (SAR), Esthet-X HD (Dentsply/DeTrey) (EST-X). Post-polymerized cylinders of 6 different thicknesses were produced and used as overlays: 2 mm, 3 mm, 3.5 mm, 4 mm, 5 mm, and 6 mm. Two-mm-thick disks were produced and employed as underlays. A standardized amount of composite paste was placed between the underlay and the overlay surfaces which were maintained at a fixed distance of 0.5 mm. Light curing of the luting composite layer was performed through the overlays for 40, 80, or 120 s. For each specimen, the composite to be cured, the cured overlay, and the underlay were made out of the same batch of resin composite. All specimens were assigned to three experimental groups on the basis of the resin composite used, and to subgroups on the basis of the overlay thickness and the curing time, resulting in 54 experimental subgroups (n = 5). Forty-five additional specimens, 15 for each material under investigation, were produced and subjected to 40, 80, or 120 s of light curing using a microscope glass as an overlay; they were assigned to 9 control subgroups (n = 5). Three Vicker's hardness (VH) indentations were performed on each specimen. Means and standard deviations were calculated. Data were statistically analyzed using 3-way ANOVA. Within the same material, VH values lower than 55% of control were not considered acceptable. The used material, the overlay thickness, and the curing time significantly influenced VH values. In the ENA group, acceptable hardness values were achieved with 3.5-mm or thinner overlays after 120 or 80 s curing time (VH 41.75 and 39.32, respectively), and with 2-mm overlays after 40 s (VH 54

  7. Palate Fracture Repair With Light-Cured Resin Splint: Technical Note.

    Science.gov (United States)

    Waldrop, Jimmy; Dale, Elizabeth L; Halsey, Jordan; Sargent, Larry A

    2015-10-01

    Palate fractures are rare, and their treatment is a matter of debate. Although some investigators have favored rigid plate fixation, others have reported successful treatment without it. Sagittal split and comminuted fractures can require rigid fixation to reduce the maxillary width; however, additional stabilization is needed. Also, palate repair without a splint is complicated by prolonged intermaxillary fixation (IMF), causing stiffness to the temporomandibular joint. We introduce a technique using a rapid light-cured resin (TRIAD TranSheet) frequently used by orthodontists for making dental retainers. Its use is similar to the splints traditionally created preoperatively, but obviates the need for making impressions, a model, and a molded splint. A series of 13 patients treated with this technique during a 5-year period is presented. The average duration of IMF was 4.7 weeks (range 3 to 6). The average duration of the palate splint was 8.4 weeks (range 5 to 12). One patient had malocclusion, but none had malunion, infection, or oronasal fistula. Our series has demonstrated a simple, cost-effective, and successful technique. It can be used alone or combined with rigid fixation and allows for a shortened duration of maxillomandibular fixation.

  8. Glass transition and degree of conversion of a light-cured orthodontic composite

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    Michela M. D. S. Sostena

    2009-12-01

    Full Text Available OBJECTIVE: This study evaluated the glass transition temperature (Tg and degree of conversion (DC of a light-cured (Fill Magic versus a chemically cured (Concise orthodontic composite. MATERIAL AND METHODS: Anelastic relaxation spectroscopy was used for the first time to determine the Tg of a dental composite, while the DC was evaluated by infrared spectroscopy. The light-cured composite specimens were irradiated with a commercial LED light-curing unit using different exposure times (40, 90 and 120 s. RESULTS: Fill Magic presented lower Tg than Concise (35-84ºC versus 135ºC, but reached a higher DC. CONCLUSIONS: The results of this study suggest that Fill Magic has lower Tg than Concise due to its higher organic phase content, and that when this light-cured composite is used to bond orthodontic brackets, a minimum energy density of 7.8 J/cm² is necessary to reach adequate conversion level and obtain satisfactory adhesion.

  9. 光固化复合树脂释放成分的检测方法及评价%Detection methods and evaluation of released components from dental light-curing resin composites

    Institute of Scientific and Technical Information of China (English)

    严敏; 郭晓伟; 宫海环; 冯丹; 张佳慧; 朱松

    2016-01-01

    Light⁃curing resin composites are widely used as dental restorative materials in clinic. Partial monomers don’ t polymerize when the resin composites are cured with light, thus turning into residual monomers which will release in the oral environment. In addi⁃tion, resin can release some components due to biodegradation induced by saliva and enzyme. All of these components may affect body tissues. Released monomers can be measured by numerous techniques including HPLC, LC/MS, HPLC/MS, and GS/MS.The aim of this article was to review the reasons for the released components, their effects on human body and detection methods of these residual monomers.%光固化复合树脂是临床广泛使用的牙体修复材料,在光照发生聚合固化时,有部分单体未发生聚合,成为残余单体,残余单体在口腔环境中进行浸出释放,唾液、酶等也会引起树脂的生物降解从而释放一些成分,这些成分可能对机体组织形成一定的影响。目前有多种检测释放单体的方法,包括高效液相色谱法、液相色谱⁃质谱联用法、高效液相色谱⁃质谱联用法、气相色谱⁃质谱联用法等。该文从残余单体释放的原因及其对人体的影响、检测方法等方面作一综述。

  10. Effect of different light curing methods on mechanical and physical properties of resin-cements polymerized through ceramic discs

    Directory of Open Access Journals (Sweden)

    Isil Cekic-nagas

    2011-08-01

    Full Text Available OBJECTIVE: The aim of this study was to compare the polimerization ability of three different light-curing units (quartz tungsten halogen, light-emitting diodes and plasma arc and their exposure modes (high-intensity and soft-start by determination of microhardness, water sorption and solubility, and diametral tensile strength of 5 dual-curing resin cements. Material and methods: A total of 720 disc-shaped samples (1 mm height and 5 mm diameter were prepared from different dual-curing resin cements (Duolink, Nexus, Bifix-QM, Panavia F and RelyX Unicem. Photoactivation was performed by using quartz tungsten halogen (high-power and soft-up modes, light-emitting diode (standard and exponential modes and plasma arc (normal and ramp-curing modes curing units through ceramic discs. Then the samples (n=8/per group were stored dry in the dark at 37°C for 24 h. The Vickers hardness test was performed on the resin cement layer with a microhardness tester (Shimadzu HMV. For sorption and solubility tests; the samples were stored in a desiccator at 37°C and weighed to a constant mass. The samples were weighed both before and after being immersed in deionized water for different periods of time (24 h and 7 days and being desiccated. The diametral tensile strength of the samples was tested in a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by nonparametric Kruskal Wallis and Mann-Whitney U tests at 5% significance level. RESULTS: Resin cement and light-curing unit had significant effects (p0.05 were obtained with different modes of LCUs. Conclusion: The study indicates that polymerization of resin cements with different light-curing units may result in various polymer structures, and consequently different mechanical and physical properties.

  11. In vitro comparative study of share bond of light cured composite resins with halogen light and argon laser, using stainless steel brackets on human premolars; Estudo comparativo in vitro da capacidade adesiva da resina fotoativada pela luz halogena e por laser de argonio, utilizando-se brackets metalicos em pre-molares humanos

    Energy Technology Data Exchange (ETDEWEB)

    Carillo, Vitoria Eugenia Bismarck

    2004-07-01

    The aim of this study in vitro was to compare the share bond strength of the light-cured composite resins Transbond XT (Unitek), with halogen light and argon laser. The Adhesive Remmant Index (ARI) was also investigated. The brackets Dyna lock (3M-UNITEK) were bonded to 75 human premolars, divided into 5 groups (15 each) according to time and the polymerization: Group H20, 15 brackets bonded with halogen light for 20s (10s both sides); Group H40, 15 brackets bonded with halogen light for 40s (20s both sides); Group A40, 15 brackets bonded with argon laser for 40s (20s both sides); Group A20, 15 brackets bonded with argon laser for 20s (10s both sides); Group A10, 15 brackets bonded with argon laser for 10s (5s both sides). The pulpal temperature changes were determined during a polymerization, not exceeding 3,5 deg C. After bonding, the teeth were submitted to a thermo cycled of 700 cycles between 5 deg C and 55 deg C, to simulate the consuming that the light cured composite resin would have in a short space of time. The specimens were then placed in PVC ring and embedded in acrylic resin (Aero-Jet). The tensile bond strength test was performed on an Universal Machine set at a crosshead speed of 1,5 mm/min, and for each rupture we registered a graphic and the best load required in Newtons, was converted to MPa and kgf. The share bond strength showed bigger values for the exposure time of 20 seconds, for the Group bonded for halogen light (H20), 7,45 kgf (7,64 MPa) and for argon laser 7,50 kgf (7,69 MPa); lesser values for the exposure time of 40s for the Group with halogen light (H40), 6,15 kgf (6,30 MPa) and argon laser Group (A40), 6,20 kgf (6,35 MPa) 0; and A10, 4,85 kgf (4,97 MPa). In the ARI Index, only A40 Group showed the 1 Index, with statistical results. In this Group, less than half of the remainder adhesive stayed on the surface of the enamel, conferring specimens failed at the enamel-adhesive interface. The results of the in vitro study demonstrate that

  12. 玻璃离子水门汀、光固化复合树脂、流动树脂修复牙体浅型楔状缺损的疗效性%Curative Effect of Glass Sonomer Cement, Light-Cured Composite Resin and Flowable Resin in the Dental Repair of Wedge-Shaped Defect

    Institute of Scientific and Technical Information of China (English)

    李文进

    2015-01-01

    Objective:To compare the clinical efficacy of glass sonomer cement, light-cured composite resin and flowable resin in the dental repair of wedge-shaped defect.Method:90 patients with wedge-shaped defect in our dental clinic were selected from January 2010 to May 2014 and they were randomly divided into three groups, 30 cases in each group. Group A was given glass sonomer cement, group B adopted light-cured composite resin and group C was given the flowable resin. After 1 year of follow-up visits, the success rate of dental repair, loss rate of materials, incidence rate of irritation symptom of dental pulp and incidence rate of secondary caries of three groups were compared.Result: In 1 year, group A had 6 cases with loss of materials,group B had 4 cases and group C had 1 case,the loss rate of materials of group A was significantly higher than that of group C, the difference was statistically significant(P0.05).The incidence rate of irritation symptom of dental pulp of three groups was respectively 10.0%,40.0% and 3.3%,compared group A and C, the difference was not statistically significant(P>0.05)The rate of Group B was significantly higher than that of Group A and Group B, the difference was statistically significant(P0.05).Compared 3 months and 1 weeks after repair, the periodontal index of group B and group C were significantly reduced, the differences were statistically significant (P0.05).Conclusion:The flowable resin is featured as great adhesion, less irritation, ability of filling in the tooth edge, reduction of permeability and fewer damages for periodontal tissues. It has a high success rate of dental repair. It can be promoted and applied in clinical treatment.%目的:对玻璃离子水门汀、光固化复合树脂、流动树脂三种材料修复牙体浅型楔状缺损的临床疗效进行对比,并做出评价。方法:选取2010年1月-2014年5月本院口腔科门诊收治的牙体浅型楔状缺损患者90例为研究对象,将患者

  13. Influence of Light-Curing Mode on the Erosion Preventive Effect of Three Different Resin-Based Surface Sealants

    Directory of Open Access Journals (Sweden)

    Florian J. Wegehaupt

    2012-01-01

    Full Text Available Objectives. To investigate if reducing the light-curing time (while maintaining similar energy density of resin-based surface sealants influences their erosion-preventive potential and mechanical stability after thermomechanical loading. Methods. Dentine samples were treated as follows: group 1—untreated, groups 2–4—Seal&Protect, groups 5–7—experimental sealer, and groups 8–10—Syntac Classic system. Groups 2, 5 and 8 were light-cured for 10 s (1000 mW/cm2, groups 3, 6 and 9 for 7 s (1400 mW/cm2, and groups 4, 7, and 10 for 3 s (3200 mW/cm2. After water storage (7 d, first measurement was performed to evaluate baseline permeability of the sealants. After a thermomechanical loading (5000 cycles, 50/5°C, 12000 brushing strokes a second evaluation of permeability was conducted (measurement 2. Permeability was tested by storing the samples in HCl (pH 2.3; 24 h and measuring the dentine calcium release by atomic absorption spectroscopy. Results. For the first and second measurements, no influence of light-exposure time on permeability was observed (ANOVA: P>0.05. No significant difference in the stability of the respective sealants was observed when light-cured for different durations. Conclusion. Shortening the light-curing time, while maintaining energy density constant, has no influence on permeability and stability of the investigated sealants.

  14. Effect of preheating and light-curing unit on physicochemical properties of a bulk fill composite.

    Science.gov (United States)

    Theobaldo, Jéssica Dias; Aguiar, Flávio Henrique Baggio; Pini, Núbia Inocencya Pavesi; Lima, Débora Alves Nunes Leite; Liporoni, Priscila Christiane Suzy; Catelan, Anderson

    2017-01-01

    The aim of this study is to evaluate the effect of composite preheating and polymerization mode on degree of conversion (DC), microhardness (KHN), plasticization (P), and depth of polymerization (DP) of a bulk fill composite. Forty disc-shaped samples (n = 5) of a bulk fill composite were prepared (5 × 4 mm thick) and randomly divided into 4 groups according to light-curing unit (quartz-tungsten-halogen [QTH] or light-emitting diode [LED]) and preheating temperature (23 or 54 °C). A control group was prepared with a flowable composite at room temperature. DC was determined using a Fourier transform infrared spectrometer, KHN was measured with a Knoop indenter, P was evaluated by percentage reduction of hardness after 24 h of ethanol storage, and DP was obtained by bottom/top ratio. Data were statistically analyzed by analysis of variance and Tukey's test (α = 0.05). Regardless of light-curing, the highest preheating temperature increased DC compared to room temperature on bottom surface. LED showed a higher DC compared to QTH. Overall, DC was higher on top surface than bottom. KHN, P, and DP were not affected by curing mode and temperature, and flowable composite showed similar KHN, and lower DC and P, compared to bulk fill. Composite preheating increased the polymerization degree of 4-mm-increment bulk fill, but it led to a higher plasticization compared to the conventional flowable composite evaluated.

  15. Effect of Different Thicknesses of Pressable Ceramic Veneers on Polymerization of Light-cured and Dual-cured Resin Cements

    Science.gov (United States)

    Cho, Seok-Hwan; Lopez, Arnaldo; Berzins, David W.; Prasad, Soni; Ahn, Kwang Woo

    2015-01-01

    Aim This study evaluated the effects of ceramic veneer thicknesses on the polymerization of two different resin cements. Materials and Methods A total of 80 ceramic veneer discs were fabricated by using a pressable ceramic material (e.max Press; Ivoclar Vivadent) from a Low Translucency (LT) ingot (A1 shade). These discs were divided into light-cured (LC; NX3 Nexus LC; Kerr) and dual-cured (DC; NX3 Nexus DC; Kerr) and each group was further divided into 4 subgroups, based on ceramic disc thickness (0.3 mm, 0.6 mm, 0.9 mm, and 1.2 mm). The values of Vickers microhardness (MH) and degree of conversion (DOC) were obtained for each specimen after a 24-hour storage period. Association between ceramic thickness, resin cement type, and light intensity readings (mW/cm2) with respect to microhardness and degree of conversion was statistically evaluated by using ANOVA. Results For the DOC values, there was no significant difference observed among the LC resin cement subgroups, except in the 1.2 mm subgroup; only the DOC value (14.0 ± 7.4%) of 1.2 mm DC resin cement had significantly difference from that value (28.9 ± 7.5%) of 1.2 mm LC resin cement (P.05). Conclusion The degree of conversion and hardness of the resin cement was unaffected with veneering thicknesses between 0.3 and 0.9 mm. However, the DC resin cement group resulted in a significantly lower DOC and MH values for the 1.2 mm subgroup. Clinical Significance While clinically adequate polymerization of LC resin cement can be achieved with a maximum 1.2 mm of porcelain veneer restoration, the increase of curing time or light intensity is clinically needed for DC resin cements at the thickness of more than 0.9 mm. PMID:26162252

  16. Study on Synergy Effect of Free Radical-cationic Hybrid Light Curing Composite Resin of Epoxy-acrylate%自由基-阳离子混杂光固化环氧/丙烯酸酯协同效应的研究

    Institute of Scientific and Technical Information of China (English)

    王亦农

    2012-01-01

    Composite resin of Epoxy-Acrylic was prepared by free radical-cationic hybrid curing systemin visible light-cured, and the influence of the proportion of free radical (CQ) and cationic initiator (DPI ~ PF6) on curing time, curing depth, linear dimension change and properties of composition were mainly studied. The results show: when the mass fraction of CQ is 0.75, the curing time is 6s, the curing depth is 7. 86mm, the linear dimension change is 0. 2%, and the synthetic performance of the composite resin is excellent. This result demonstrated that free radical-cationic hybrid curing system combined the advantages of radical and cationic polymerization, and exhibited a better synergy effect.%采用可见光引发自由基-阳离子混杂光固化体系,固化环氧/丙烯酸酯制备的复合树脂,重点研究了自由基光引发剂樟脑醌和阳离子光引发剂二苯基碘锚六氟磷酸盐质量比对固化时间、固化深度、线尺寸变化率及树脂性能的影响。结果表明:在可见光的照射下,当樟脑醌在混合引发剂中的质量分数为0.75时,固化时间为6s,光固化深度为7.86ram,线尺寸变化率为0.2%,固化复合树脂的综合性能优良;很好地证明了自由基一阳离子混杂光固化体系结合了自由基聚合和阳离子聚合的优点,表现出较好的协同效应。

  17. The effect of light-curing source and mode on microtensile bond strength to bovine dentin

    OpenAIRE

    Amaral, CM; Peris, AR; Ambrosano, GMB; Swift, EJ; Pimenta, LAF

    2006-01-01

    Purpose: The purpose of this study was to evaluate the effects of different light-curing techniques on the microtensile bond strength of hybrid and packable resin composite to dentin. The null hypotheses were that different light-curing techniques do not affect the adhesion of resin composites to tooth structure and that different resin composites do not have a similar bond to dentin. Materials and Methods: One hundred four box-shaped buccal preparations were made and dentin/enamel adhesive w...

  18. 2种光固化灯固化对3种不同复合树脂聚合收缩的影响%Effect of polymerization-shrinkages of different resin composite curing by two different light curing units

    Institute of Scientific and Technical Information of China (English)

    邓小林; 张保卫; 陆鹏

    2011-01-01

    PURPOSE: To investigate the effect of light-emitting diode (LED) light curing unit (LCU) and quartztungsten (QTH) LCU on the polymerization-shrinkage of different resin composites.METHODS: Three composites Z100,Z250, AP-X were irradiated by QTH LCU and LED LCU.Polymerization-shrinkage of 50s and 400s after the composites curing were measured by 3D-profile measuring apparatus by phase-shifted projected grating.The polymerization-shrinkage of LED and QTH curing composites were analysed by SPSS12.0 software package of one-way ANOVA.RESULTS: At 50s curing and 400s curing period, the polymerization- shrinkage of Z100, Z250 resin was different by QTH LCU and LED LCU curing, the polymerization-shrinkage by LED LCU curing was less than that by QTH LCU (P<0.05); the polymerization-shrinkage of AP-X was not statistically different by QTH LCU and LED LCU curing (P>0.05).CONCLUSUINS: The polymerization-shrinkage of Z100,Z250 resin is statistically less cured by LED LCU than QTH;the polymerization-shrinkage of AP-X resin is not statistically different cured by QTH LCU and LED LCU.Supported by Research Fund of Science and Technology Commission of Shanghai Municipality(08DZ2271100).%目的:比较2种光固化灯对3种复合树脂聚合收缩的影响.方法:相移投影栅形貌测量仪测量Z100、Z250、AP-X 等3种复合树脂在卤素灯和发光二极管同化灯开始固化后50s及开始固化后400s的树脂聚合收缩量.使用SPSS12.0 软件包对 QTH 及LFD 固化组聚合收缩量进行单因素方差分析.结果:在开始固化后50s和400s,QTH同化灯和 LED 固化灯固化Z100、Z250树脂产生的聚合收缩量有显著差异,QTH 固化灯固化Z100、Z250树脂产生的聚合收缩量显著大于LED固化灯(P<0.05),QTH和 LED 固化灯固化 AP-X 树脂产生的聚合收缩量则无统计学差异(P>0.05).结论:LED及QTH固化灯固化Z100、Z250树脂产生的聚合收缩影响有显著差异(P<0.05),LED及QTH固化灯固化 AP-X 产生的

  19. EVALUATION OF DIELECTRIC CURING MONITORING INVESTIGATING LIGHT-CURING DENTAL FILLING COMPOSITES

    Directory of Open Access Journals (Sweden)

    Johannes Steinhaus

    2011-05-01

    Full Text Available The aim of this study is the evaluation of a dielectric analysis (DEA method monitoring the curing behaviour of a light curing dental filling material in real-time. The evaluation is to extract the influence of light intensity on the photo-curing process of dental composite filling materials. The intensity change is obtained by measuring the curing process at different sample depth. It could be shown that increasing sample thickness, and therefore exponentially decreasing light intensity, causes a proportional decrease in the initial curing rate. Nevertheless, the results give rise to the assumption that lower illumination intensities over a long period cause higher overall conversion, and thus better mechanical properties. This would allow for predictions of the impact of different curing-rates on the final mechanical properties.

  20. Effect of Layering Methods, Composite Type, and Flowable Liner on the Polymerization Shrinkage Stress of Light Cured Dental Composites

    Science.gov (United States)

    2011-08-01

    thickness of flowable liner, use of RMGI (resin modified glass ionomer ) liner, and light curing methods on the cuspal deflection should be...was pressed between a slide glass and a flexible cover glass (Marienfeld, Germany) using a metal wire with 0.5 mm diameter as a spacer, producing...a disc-shaped specimen 0.5 mm in thickness and 6.0 mm in diameter. The tip of a LVDT probe was placed on the center of the cover glass and set to

  1. SWELLING AND WETTABILITY OF LIGHT-CURED METHACRYLATE-BASED DENTAL RESINS PREPARED FROM CHOLIC ACID

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    2 '-methacryloxy-3α, 7α 12α- trimethacryloyl cholic acid ethyl ester (CAGE4MA) has been prepared from cholic acid. Photo-polymeric resins were prepared from CAGE4MA. 2,2-bis[4-(2-hydroxy-3-methacrylyloxypropoxy)phenyl]propane (bis-GMA) was used for comparison, triethyleneglycol dimethacrylate (TEGDMA) was used as diluent. The polymerization was initiated by camphoroquinone (CQ)/N, N-dimethylaminoethyl methacrylate (DMAEMA) system. The conversion of CAGE4MA was 39% when the reaction time is 60s, which is lower than bis-GMA and TEGDMA.The swelling value of CAGE4MA resin was 0.41% in distilled water, which is much lower than those of bis-GMA resin (2.04%) and TEGDMA resin (4.77%) under the same conditions. Copolymers from CAGE4MA and TEGDMA have been prepared. With the increase of TEGDMA in mixture, the degree of conversion of CA GE4MA and swelling value increased. The swelling values of photocured resins in 0. 1mol/L HCl were also measured.

  2. Influence of Photoinitiator and Light-Curing Source on Bond Strength of Experimental Resin Cements to Dentin.

    Science.gov (United States)

    Segreto, Dario Raimundo; Naufel, Fabiana Scarparo; Brandt, William Cunha; Guiraldo, Ricardo Danil; Correr-Sobrinho, Lourenço; Sinhoreti, Mário Alexandre Coelho

    2016-01-01

    This study evaluated the bond strength (BS) of experimental resin cements formulated with different photoinitiators when activated by two kinds of light-curing units (LCUs) through a ceramic material. Seven resin blends with different camphorquinone (CQ) and/or phenylpropanedione (PPD) concentrations (weight) were prepared: C5: 0.5% CQ; C8: 0.8% CQ; P5: 0.5% PPD; P8: 0.8% PPD; C1P4: 0.1% CQ and 0.4% PPD; C4P1: 0.4% CQ and 0.1% PPD; C4P4: 0.4% CQ and 0.4% PPD. Two LCUs were used: one quartz-tungsten-halogen (QTH - 850 mW/cm²) and one light-emitting diode (LED - 1300 mW/cm²). The microtensile bond strength of each blend was assessed. Data were submitted to two-way ANOVA and Tukey's test (α=0.05). The BS values did not exhibit significant differences for LCUs, regardless of the photoinitiator type. Three cements showed significant differences: P5 and C5 had higher BS with QTH, and C4P1 with LED. For QTH, P5 showed the highest and C1P4 the lowest BS. For the LED, C4P1 showed the highest BS of all the cements. The results indicated that PPD was a viable alternative in the formulation of photocured resin cements, reducing or eliminating CQ that is yellowish without impairing the bond strength. Furthermore, both LED and QTH were effective in curing resin cements that contain PPD or CQ.

  3. Effects of radiant exposure and wavelength spectrum of light-curing units on chemical and physical properties of resin cements

    Directory of Open Access Journals (Sweden)

    Adriano Fonseca Lima

    2016-11-01

    Full Text Available Objectives In this study, we evaluated the influence of different radiant exposures provided by single-peak and polywave light-curing units (LCUs on the degree of conversion (DC and the mechanical properties of resin cements. Materials and Methods Six experimental groups were established for each cement (RelyX ARC, 3M ESPE; LuxaCore Dual, Ivoclar Vivadent; Variolink, DMG, according to the different radiant exposures (5, 10, and 20 J/cm2 and two LCUs (single-peak and polywave. The specimens were made (7 mm in length × 2 mm in width × 1 mm in height using silicone molds. After 24 hours of preparation, DC measurement was performed using Fourier transform infrared spectrometry. The same specimens were used for the evaluation of mechanical properties (flexural strength, FS; elastic modulus, E by a three-point bending test. Data were assessed for normality, after which two-way analysis of variance (ANOVA and post hoc Tukey's test were performed. Results No properties of the Variolink cement were influenced by any of the considered experimental conditions. In the case of the RelyX ARC cement, DC was higher when polywave LCU was used; FS and E were not influenced by the conditions evaluated. The LuxaCore cement showed greater sensitivity to the different protocols. Conclusions On the basis of these results, both the spectrum of light emitted and the radiant exposure used could affect the properties of resin cements. However, the influence was material-dependent.

  4. Evaluation of the Effect of Porcelain Laminate Thickness on Degree of Conversion of Light Cure and Dual Cure Resin Cements Using FTIR

    Science.gov (United States)

    Hoorizad Ganjkar, Maryam; Heshmat, Haleh; Hassan Ahangari, Reza

    2017-01-01

    Statement of the Problem: Increasing the thickness of the veneering porcelain may affect the polymerization of resin cements. Incomplete polymerization of resin cements can lead to compromised quality of restoration and decrease the longevity of indirect restorations. Purpose: This study sought to assess the effect of IPS Empress porcelain thickness on the degree of conversion of light-cure and dual-cure resin cements using Fourier transform infrared spectroscopy. Materials and Method: In this experimental study, IPS Empress porcelain discs (A2 shade) with 10mm diameter and 0.5, 1 and 1.5 mm thicknesses were fabricated. Choice2 (Bisco, USA) and Nexus3 (Kerr, USA) resin cements were light cured through the three porcelain thicknesses in two groups of 3 samples using a LED light-curing unit (LEDemetron II; Kerr, USA). The control group samples were cured individually with no porcelain disc. The degree of conversion of resin cements was determined using FTIR (Bruker; Equinox55, Germany). The data were analyzed using Dunn’s test. Results: The degree of conversion (in percent) beneath the 0.5, 1.5 and 2 mm thicknesses of IPS Empress was 68.67±0.88, 71.06±0.94 and 72.51±0.41 for Choice2 resin cement and 69.60±2.12, 69.64±1.63 and 69.24±2.12 for Nexus3, respectively. Porcelain thickness and type of resin cement had no significant effect on degree of conversion (p≥ 0.05). Conclusion: It seems that increasing the porcelain thickness by up to 1.5 mm has no adverse effect on degree of conversion of both dual cure and light cure resin cements evaluated in this study. PMID:28280757

  5. Degree of conversion of micro-hybrid, nano-hybrid and Ormocer composites using LED and QTH light-curing units

    Directory of Open Access Journals (Sweden)

    Seied Mostafa Fatemi

    2012-01-01

    Full Text Available Background and Aims: The aim of this study was to measure the degree of conversion (DC of three types of composite resins (micro-hybrid, nano-hybrid and Ormocer with different light curing units (LED LCU and QTH LCU in two depths.Materials and Methods: Three commercially available dental resin composites were used in this study: (Tetric Ceram, Ivoclar Vivadent, Liechtenstein-A2 shade, (Tetric Evoceram, Ivoclar Vivadent, Liechtenstein-A2 shade, (Ceram X, Dentsply, Germany-M2 shade. Specimens were divided into two groups, 5 specimens were photo-activated by QTH unit (Coltolux 75-Colten and the other five specimens were cured by LED (Demi-Kerr. Then each specimen was sectioned at the top surface and at 2-mm depth. The DC was measured by FT-IR(Bruker-tensor 27. The data were analyzed by 3-way ANOVA test.Results: There was significant difference between tested composite resins (P<0.001. The results of top surfaces were significantly different from those observed at 2-mm depth (P<0.001. The type of curing unit affected the polymerization of Ceram X resin composite.Conclusion: This study showed a significant difference in the degree of conversion in different thicknesses within three groups of resin composites.

  6. Effect of different photo-initiators and light curing units on degree of conversion of composites

    Directory of Open Access Journals (Sweden)

    William Cunha Brandt

    2010-09-01

    Full Text Available The aim of this study was to evaluate: (i the absorption of photo-initiators and emission spectra of light curing units (LCUs; and (ii the degree of conversion (DC of experimental composites formulated with different photo-initiators when activated by different LCUs. Blends of BisGMA, UDMA, BisEMA and TEGDMA with camphorquinone (CQ and/ or 1-phenyl-1,2-propanedione (PPD were prepared. Dimethylaminoethyl methacrylate (DMAEMA was used as co-initiator. Each mixture was loaded with 65 wt% of silanated filler particles. One quartz-tungsten-halogen - QTH (XL 2500, 3M/ESPE and two lightemitting diode (LED LCUs (UltraBlue IS, DMC and UltraLume LED 5, Ultradent were used for activation procedures. Irradiance (mW/cm² was calculated by the ratio of the output power by the area of the tip, and spectral distribution with a spectrometer (USB 2000. The absorption curve of each photo-initiator was determined using a spectrophotometer (Varian Cary 5G. DC was assessed by Fourier transformed infrared spectroscopy. Data were submitted to two-way ANOVA and Tukey's test (5%. No significant difference was found for DC values when using LED LCUs regardless of the photo-initiator type. However, PPD showed significantly lower DC values than composites with CQ when irradiated with QTH. PPD produced DC values similar to those of CQ, but it was dependent on the LCU type.

  7. 光敏树脂修复前牙列稀疏%THE FRONT INTERDENTAL SPACES WERE TREATED BY LIGHT CURED RESIN

    Institute of Scientific and Technical Information of China (English)

    赵琼芝; 刘国华

    2001-01-01

    Objective: The clinical effect of light cured resin in treating front interdental spaces was studied. Methods: 116 patients with front interdental spaces were treated using acid--etching bonding technique, light cured resin and followed up from 6 months to 6 years. Results: More than 89% effective rate was found in the first three years and then gradually reduced with75%, 58%, 40% effective rate in 4th, 5th, 6th year.Conclusion: Light cured resin resin was effective in treating front interdental spaces.%目的:观察光敏树脂修复前牙列稀疏的临床效果。方法:用此法修复116名前牙稀疏患者,观察0.5年~6年,并简析操作要点及失败原因。结果:3年内有效率为89%以上,第4、5、6年分别为75%、58%、40%,示第4年以后有效率明显下降。结论:光敏树脂是修复前牙列稀疏较理想的材料

  8. Influence of cavity preparation, light-curing units, and composite filling on intrapulpal temperature increase in an in vitro tooth model.

    Science.gov (United States)

    Choi, S H; Roulet, J F; Heintze, S D; Park, S H

    2014-01-01

    This study examined the effect of both the tooth substance and restorative filling materials on the increase in pulp chamber temperature when using light-curing units with different power densities. The tip of a temperature sensor was positioned on the pulpal dentinal wall of the buccal side of a maxillary premolar. Metal tubes were inserted in the palatal and buccal root of the tooth, one for water inflow and the other for water outflow. Polyethylene tubes were connected from the metal tubes to a pump to control the flow rate. For the unprepared tooth group (group 1), the tooth was light-cured from the buccal side using two light-curing units (three curing modes): the VIP Junior (QTH, BISCO, Schaumburg, IL, USA) and the Bluephase LED light-curing units (two modes: LEDlow and LEDhigh; Ivoclar Vivadent, Schaan, Liechtenstein). The power densities of each light-curing unit for the LEDlow, QTH, and LEDhigh modes were 785 mW/cm(2), 891 mW/cm(2), and 1447 mW/cm(2), respectively. All light-curing units were activated for 60 seconds. For the prepared tooth group (group 2), a Class V cavity, 4.0 mm in width by 4.0 mm in height by 1.8 mm in depth in size, was prepared on the buccal surface of the same tooth for the temperature measurement. The light-curing and temperature measurements were performed using the same methods used in group 1. The cavity prepared in group 2 was filled with a resin composite (Tetric N Ceram A3 shade, Ivoclar Vivadent) (group 3) or a flowable composite (Tetric N Flow with A3 shade, Ivoclar Vivadent) (group 4). The light-curing and temperature measurements were performed for these groups using the same methods used for the other groups. The highest intrapulpal temperature (TMAX) was measured, and a comparison was conducted between the groups using two-way analysis of variance with a post hoc Tukey test at the 95% confidence level. The TMAX values were as follows: 38.4°C (group 1), 39.0°C (group 2), 39.8°C (group 3), and 40.3°C (group 4) for the

  9. Effect of the irradiance distribution from light curing units on the local micro-hardness of the surface of dental resins.

    Science.gov (United States)

    Haenel, Thomas; Hausnerová, Berenika; Steinhaus, Johannes; Price, Richard B T; Sullivan, Braden; Moeginger, Bernhard

    2015-02-01

    An inhomogeneous irradiance distribution from a light-curing unit (LCU) can locally cause inhomogeneous curing with locally inadequately cured and/or over-cured areas causing e.g. monomer elution or internal shrinkage stresses, and thus reduce the lifetime of dental resin based composite (RBC) restorations. The aim of the study is to determine both the irradiance distribution of two light curing units (LCUs) and its influence on the local mechanical properties of a RBC. Specimens of Arabesk TOP OA2 were irradiated for 5, 20, and 80s using a Bluephase® 20i LCU in the Low mode (666mW/cm(2)), in the Turbo mode (2222mW/cm(2)) and a Celalux® 2 (1264mW/cm(2)). The degree of conversion (DC) was determined with an ATR-FTIR. The Knoop micro-hardness (average of five specimens) was measured on the specimen surface after 24h of dark and dry storage at room temperature. The irradiance distribution affected the hardness distribution across the surface of the specimens. The hardness distribution corresponded well to the inhomogeneous irradiance distributions of the LCU. The highest reaction rates occurred after approximately 2s light exposure. A DC of 40% was reached after 3.6 or 5.7s, depending on the LCU. The inhomogeneous hardness distribution was still evident after 80s of light exposure. The irradiance distribution from a LCU is reflected in the hardness distribution across the surface. Irradiance level of the LCU and light exposure time do not affect the pattern of the hardness distribution--only the hardness level. In areas of low irradiation this may result in inadequate resin polymerization, poor physical properties, and hence premature failure of the restorations as they are usually much smaller than the investigated specimens. It has to be stressed that inhomogeneous does not necessarily mean poor if in all areas of the restoration enough light intensity is introduced to achieve a high degree of cure. Copyright © 2014 Academy of Dental Materials. Published by

  10. Effect of Distance on Light Transmission Through Polymerized Resin Composite.

    Science.gov (United States)

    Aromaa, M K; Lassila, L V J; Vallittu, P K

    2017-09-01

    Light transmittance of dental composites varies between products and shades, but also light curing units differ to each other in their irradiance and fiber optic structure of curing tip. The aim of this study was to investigate whether there is linear relationship between the distance of the curing tip to the resin composite and irradiance at lower surface of the resin composite. Disks of 1 mm thickness (6mm diameter) were fabricated. Light transmittance (intensity) through the disk was measured at distance of 0, 2, 4, 6, 8, 10 mm from the light tip with two light curing units Elipar S10 (3M-ESPE) and Silverlight (GC). Irradiance ratio (irradiance on the sensor surface without the composite disk / with the composite disk) was calculated and plotted against the distance of the light curing tip. Statistical analysis was carried out using analysis of covariance (ANCOVA, Tukey's, α =0.05). Irradiance ratio varied between 18% to 24% with Silverlight and 21% to 26% with Elipar S10 light curing units. There were statistically significant differences between the ratios with different distances of the light curing tip (p⟨0.05). Interestingly, the highest irradiance ratio for Elipar S10 unit was found with 4 mm distance of the tip, whereas Silverlight unit had the highest ratio with 6 mm distance. Out of two tested resin composites, the flowable composite showed higher irradiance ratio than regular packable resin composite. Increase of distance of the light curing tip from the composite surface decreased the absolute irradiance underneath of composite, as expected. However, there seemed to be device dependent optimal distance of 4-6 mm to reach the most efficient irradiance ratio through the composite resin keeping in mind that most efficient transmission of light through the material is reached by having light curing tip in contact to the material. Copyright© 2017 Dennis Barber Ltd.

  11. 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...

  12. 光固化流体树脂美容修复乳前牙龋的疗效观察%Clinical effect of light curing fl uid resin in the treatment of dental caries in primary teeth

    Institute of Scientific and Technical Information of China (English)

    高艳蕾; 李凌; 袁昌青

    2015-01-01

    ObjectiveTo explore the clinical effect of light curing fluid resin used in cosmetic restoration of dental caries.MethodsFrom February 2014 to April 2015, 92 patients with dental caries were selected. The patients were divided into observation group and control group with 40 cases, 52 cases were treated by light curing fl uid resin and the control group was treated with light cured composite resin. The effect and complications of two groups were compared.ResultsThe total recovery rate of the observation group was higher than that of the control group, and the incidence of complications was lower than that of the control group(P<0.05).ConclusionThe clinical effect of light curing fluid resin used in cosmetic restoration of anterior teeth is signifi cant. Worthy of clinical popularization and Application.%目的:观察光固化流体树脂用于美容修复乳前牙龋的疗效。方法选取2014年2月~2015年4月某院收治的乳前牙龋患儿92例,将其按照治疗所用方法分为观察组52例与对照组40例,观察组行光固化流体树脂修复,对照组行光固化复合树脂修复,比较两组修复效果及并发症情况。结果观察组总修复率比对照组高,且并发症发生率比对照组低,差异有统计学意义(P<0.05)。结论光固化流体树脂用于美容修复乳前牙的疗效显著。值得临床推广应用。

  13. Effect of light-cure initiation time on polymerization and orthodontic bond strength with a resin-modified glass-ionomer

    Science.gov (United States)

    Thomas, Jess

    Introduction: The polymerization and acid-base reactions in resin-modified glass-ionomers (RMGI) are thought to compete with and inhibit one another. The objective of this study was to examine the effect of visible light-cure (VLC) delay on the polymerization efficiency and orthodontic bond strength of a dual-cured RMGI. Methods: An RMGI light-cured immediately, 2.5, 5, or 10 minutes after mixing comprised the experimental groups. Isothermal and dynamic temperature scan differential scanning calorimetry (DSC) analysis of the RMGI was performed to determine extents of VLC polymerization and acid-base reaction exotherms. Human premolars (n = 18/group) were bonded with the RMGI. Shear bond strength and adhesive remnant index (ARI) scores were determined. Results: DSC results showed the 10 minute delay RMGI group experienced significantly (P 0.05) were noted among the groups for mean shear bond strength. A chi-square test showed no significant difference (P = 0.428) in ARI scores between groups. Conclusions: Delay in light-curing may reduce polymerization efficiency and alter the structure of the RMGI, but orthodontic shear bond strength does not appear to be compromised.

  14. Optimizing light-cured composite through variations in camphorquinone and butylhydroxytoluene concentrations

    Directory of Open Access Journals (Sweden)

    Hani NASSAR

    2016-01-01

    Full Text Available Abstract The use of a free-radical polymerization inhibitor, butylhydroxytoluene (BHT, and a common photo-initiator, camphorquinone (CQ, to reduce polymerization stress in dental composite was investigated in this study. Samples were prepared by mixing Bis-GMA, UDMA, and TEGDMA at a 1:1:1 ratio (wt%, and silanized borosilicate glass fillers at 70 wt% were added to form the composite. Sixteen groups of resin composite were prepared using combinations of four CQ (0.1%, 0.5%, 1.0%, and 1.5% and four BHT (0.0%, 0.5%, 1.0%, and 1.5% concentrations. For each group, six properties were tested, including flexural strength (FS, flexural modulus (FM, degree of conversion (DC, contraction stress (CS, stress rate, and gel point (GP. The effects of CQ and BHT combinations on each of these properties were evaluated using two-way analysis of variance (ANOVA and Fisher’s Protected Least Significant Differences test at the 5% significance level. Groups with low CQ and BHT showed moderate values for FS, FM, and CS with a 70% DC. Increasing the BHT concentration caused a decrease in CS and DC with an increase in GP values. Increasing the CQ content led to a steady increase in values for FS and FM. High CQ and BHT combinations showed the most promising values for mechanical properties with low stress values.

  15. [Effects of silicon carbide on the cure depth, hardness and compressive strength of composite resin].

    Science.gov (United States)

    Wang, Ke; Lin, Yi'na; Liu, Xiaoqing

    2009-08-01

    The hardness, compressive strength and cure depth are important indices of the composite resin. This investigation was made with regard to the effects of silicon carbide on the cure depth, hardness and compressive strength of the light-curing composite resin. Different amounts of silicon carbide were added to the light-curing composite resin, which accounted for 0 wt%, 1 wt%, 0.6 wt%, 0.3 wt%, 0.1 wt%, 0.05 wt% and 0.005 wt% of the composite resin, respectively. The hardness, compressive strength and cure depth of the six afore-mentioned groups of composite resin were measured by the vernier caliper, the vickers hardness tester and the tensile strength of machine, respectively. The results showed that silicon carbide improved the hardness and compressive strength of the light-curing composite resin,when the concentration was 0.05 wt%. And the cure depth was close to that of control.

  16. 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.

  17. [Improvement of light-cured indirect inlays durability by means of electromagnetic field].

    Science.gov (United States)

    Nidzel'skiĭ, M Ia; Korotetskaia-Zinkevich, V L

    2014-01-01

    The main strength characteristics of light-cured resins used for replacement of dental hard tissues defects are destructive stress by compression, microhardness, resistance to abrasion, impact and water absorption. The study focuses on some strength features of composite materials for inlays processed by electromagnetic field. Four sample series of light cured resin (Charisma, Heraus Kulzer, Germany) were used to assess strength features changes in various curing methods: 10 control samples were polymerized by conventional light-curing device, while 30 were additionally processed by electromagnetic field of various intensity (60, 80 and 100 Oe, 10 samples for each group). The obtained results confirm the positive effects of electromagnetic field on strength features of light-cured resins which improves the quality of inlays.

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

    OpenAIRE

    Naeimi Akbar, H.; Moharamzadeh, K.; Wood, D. J.; van Noort, R

    2012-01-01

    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 ...

  19. Comparison of the Shear Bond Strength of Light-cured and Chemically-cured Resin Adhesive%光固化和化学固化树脂粘接剂剪切强度的对比研究

    Institute of Scientific and Technical Information of China (English)

    张隆祺; 王野平

    2001-01-01

    Objective To compare the shear bond strength of light-cured and chemically-cured resin adhesive. Methods Twenty recently extracted human premolars were randomly divided into two groups of 10 each.: Group A, using the chemically-cured resin adhesive (Jing Jinenamel adhesive) and Group B, using the light-cured resin adhesive (Transbond XT,3M Unitek). The brackets were bonded to prepared enamel surfaces and the samples were placed in a water bath at 37℃ for 24 hours, then measured the shear bond strength and assessed the remaining adhesive after debonded. Results The shear bond strength and assessing the remaining adhesive after debonded both had no statistical significanct difference between two adhesives. Conclusion The light-cured and the chemically-cured resin adhesive both have strong bond strength, but the light-cured resin adhesive has the advantage to offer more sufficient time for positioning and bonding the brackets, so it is recommended for using.%-05)。结论光固化和化学固化树脂粘接剂均具有较强的粘接强度,但光固化树脂粘接剂能够为托槽的定位和粘接提供充足的时间,推荐使用。

  20. Bonded composite resin crowns for primary incisors: technique update.

    Science.gov (United States)

    Croll, T P

    1990-02-01

    A technique for restoration of carious primary maxillary incisors with a hybrid visible light-curing composite resin and a dentinal bonding agent is described. Careful use of this technique and the new materials can provide a restoration that is esthetic and resistant to fracture and displacement. The technique requires careful preparation of the operative field and precise handling of the restorative materials. The method is illustrated by the placement of bonded composite resin crowns in a 3-year-old boy.

  1. Clinical evaluation of pit and fissure sealant with light-cured flowable resin and light-cured pit and fissure sealants%光固化封闭剂与光固化流体树脂窝沟封闭临床效果评价

    Institute of Scientific and Technical Information of China (English)

    曹慧珍; 束陈斌; 汪隼; 黄伟

    2011-01-01

    目的:比较光固化流体树脂与光固化封闭剂在实施窝沟封闭方面防龋成本及保留率的差异.方法:选择上海市7~10岁儿童256名,口腔内至少有1对第一恒磨牙无龋.每名儿童一侧的恒磨牙用光固化流体树脂进行窝沟封闭,另一侧用传统光固化封闭剂进行窝沟封闭,使用便携式牙科椅吸取唾液,并用棉卷隔湿.使用2种方法操作时记录每个牙封闭所用去的棉卷数和操作时间.1a后,检查2种材料在牙面上的保留情况.所有操作均在学校内施行,检查由2名医师用镰形探针进行,采用SPSS 10.0软件包对数据进行统计学分析.结果:使用传统光固化封闭剂进行窝沟封闭操作时间每牙需3.53min,而光固化流体树脂组需3.32min(P<0.05).在封闭剂的保留率方面,光固化流体树脂组显著高于传统的窝沟封闭组(P<0.05).结论:应用光固化流体树脂进行窝沟封闭,能用较短操作时间达到防龋目的,适合在学校推广应用.%PURPOSE: To evaluate the difference between light-cured flowable resin and light-cured pit and fissure sealant in the cost and retention rate of pit and fissure sealant treatment. METHODS: Two hundred and fifty six children aged from 7 to 10 years were selected in this study. Each of them had at least two caries-free first molars. One first molar was sealed with light-cured flowable resin and the other one was sealed with traditional light-cured sealant. The portable dental chair were used to absorb saliva and cotton rolls were applied for moisture control. The operation time and number of cotton rolls used were recorded. After one year, the reservation of material was checked by two dentists using explorer. All the procedures were undertaken in schools.The data were analyzed using SPSS 10.0 software package. RESULTS: It took 3.53 minutes for one tooth to be sealed with traditional light-cured sealant and 3.32 minutes with light-cured flowable resin (P<0.05). The retention

  2. Effect of modulated photo-activation on polymerization shrinkage behavior of dental restorative resin composites

    NARCIS (Netherlands)

    T.T. Tauböck; A.J. Feilzer; W. Buchalla; C.J. Kleverlaan; I. Krejci; T. Attin

    2014-01-01

    This study investigated the influence of modulated photo-activation on axial polymerization shrinkage, shrinkage force, and hardening of light- and dual-curing resin-based composites. Three light-curing resin composites (SDR bulk-fill, Esthet X flow, and Esthet X HD) and one dual-curing material (Re

  3. In vitro analysis of shear bond strength and adhesive remnant index comparing light curing and self-curing composites

    Directory of Open Access Journals (Sweden)

    Murilo Gaby Neves

    2013-06-01

    Full Text Available OBJECTIVE: To evaluate, in vitro, the shear bond strength of self-curing (ConciseTM - 3M and Alpha Plast - DFL and light-curing composites (TransbondTM XT - 3M and Natural Ortho - DFL used in orthodontics bonding, associated to Morelli metal brackets, with further analysis of adhesive remnant index (ARI and enamel condition in scanning electron microscopy (SEM. METHODS: Forty human premolars, just extracted and stored in physiologic solution 0.9 % were used. Randomly, these samples were divided in four groups: G1 group, the brackets were bonded with ConciseTM - 3M composite; in G2 group, Alpha Plast - DFL composite was used; in G3 group, TransbondTM XT - 3M was used; in G4 group, Natural Ortho - DFL composite was used. These groups were submitted to shear strength tests in universal testing machine, at 0.5 mm per minute speed. RESULTS: Statistical difference between G3 and G4 groups was recorded, as G4 showing higher strength resistance than G3. In the other hand, there were no statistical differences between G1, G2 and G3 and G1, G2 and G4 groups. ARI analysis showed that there was no statistical difference between the groups, and low scores were recorded among then. The scanning electron microscopy (SEM analysis revealed the debonding spots and the enamel surface integrity. CONCLUSIONS: Shear bond strength was satisfactory and similar between the composites, however Natural Ortho - DFL revealed best comparing to TransbondTM XT - 3M.

  4. 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; de QUEIROZ, Alexandra Mussolino; da SILVA, Léa Assed Bezerra

    2016-01-01

    ABSTRACT The successful use of composite resins in Dentistry depends on physicochemical properties, but also on the biological compatibility of resins, because of the close association between pulp and dentin. Objective 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. Material and Methods 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). Results 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). Conclusions 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. PMID:27556204

  5. Hardness Evaluation of Composite Resins Cured with QTH and LED

    Directory of Open Access Journals (Sweden)

    Behnaz Esmaeili

    2014-03-01

    Full Text Available Background and aims. Today light cured composites are widely used. Physical and mechanical properties of composites are related to the degree of conversion. Light curing unit (LCU is an important factor for composite polymerization. Aim of this study is evaluation of composite resins hardness using halogen and LED light curing units. Materials and methods. In this study, 30 samples of Filtek Z250 and C-Fill composite resins were provided. Samples were light cured with Ultralume2, Valo and Astralis7. Vickers hardness number (VHN was measured in 0, 1, 2 mm depth. Statistical analysis used: Data were analysed by SPSS software and compared with each other by T-test, one-way and twoway ANOVA and Post-hoc Tukey test. Results. In Filtek Z250, at top surface, VHN of Ultralume2 was higher than VHN of Valo (P = 0.02 and Astralis7 (P = 0.04, but in depth of 1, 2 mm, VHN of Ultralume2 and Astralis7 were almost the same and both LCUs were more than Valo which the difference between Ultralume2 and Valo was significant in depth of 1mm (0.05 and 2mm (0.02. In C-Fill composite, at top surface, Astralis7 showed higher VHN, but in depth of 2 mm, performance of all devices were rather similar. Conclusion. In Z250, which contains camphorquinone initiator, light cure LED Ultra-lume2 with narrow wavelength showed higher hardness number than Valo. In C-fill, in top surface, Astralis7 with more exposure time, resulted higher VHN. But In depth of 2 mm, various light curing devices had rather similar hardness number.

  6. Comparison of the Effect of Two Incremental Composite Placement and Two Light Curing Methods on Microleakage of Composite Class I Restorations

    Directory of Open Access Journals (Sweden)

    E. Yarmohammadi

    2014-10-01

    Full Text Available Introduction & Objective: Light curing and composite placement is effective on microleakage prevention. The aim of the present study was to compare the effect of two incremental com-posite placement and two light curing methods on microleakage of composite class one resto-rations. Materials & Methods: In this experimental study 60 maxillary premolars after class one prepa-ration were assigned to 4 different groups according to light curing method (soft or full power and two incremental methods (horizontal or oblique 1. Horizontal incremental placement with full power cure 2. Horizontal incremental placement with soft star cure 3. Oblique incremental placement with full power cure and 4. Oblique incremental placement with soft start cure. After etching and bonding, teeth were restored with Tetric Ceram HB composite. Samples were thermocycled and immersed in 0.2% fuchsin solution for 48 hours. Samples were sectioned buccolingually and evaluated under stereomicroscope (40×. Micro-leakage was scored as follow; 0: No microleakage, 1: Microleakage till enamel edge, 2: Microleakage between dentin edge and floor of the cavity and 3:Microleakage extended to the floor of cavity or pulp. Data was analyzed by SPSS software version 16 using Kruscal Wallis and Mann Whitney U test at the significant level of 0.05. Results: There was a significant difference between four experimental groups, micro leakage (P=0.000. The mean micro leakage of group 1 was significantly different from groups 2, 3 and 4 (P0.05. Conclusion: Restorative material placement technique and curing mode was effective on the microleakage of class 1 composite restoration, however, curing mode was more effective on reduced composite microleakage compared to the placement technique. (Sci J Hamadan Univ Med Sci 2014; 21 (3: 177-184

  7. Review: Resin Composite Filling

    OpenAIRE

    Desmond Ng; Jimmy C. M. Hsiao; Keith C. T. Tong; Harry Kim; Yanjie Mai; Keith H. S. Chan

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin ...

  8. Clinical evaluation on porcelain laminate veneers bonded with light-cured composite: results up to 7 years.

    Science.gov (United States)

    D'Arcangelo, Camillo; De Angelis, Francesco; Vadini, Mirco; D'Amario, Maurizio

    2012-08-01

    The purpose of this study was to evaluate the clinical performance of laminate porcelain veneers bonded with a light-cured composite. Thirty patients were restored with 119 porcelain laminate veneers. The veneers were studied for an observation time of 7 years. Marginal adaptation, marginal discoloration, secondary caries, color match, and anatomic form were clinically examined following modified United States Public Health Service (USPHS) criteria. Each restoration was also examined for cracks, fractures, and debonding. Pulp vitality was verified. In addition, plaque and gingival indexes and increase in gingival recession were recorded. Survival rate evaluating absolute failures and success rate describing relative failures were statistically determined, using both restoration and patient-related analyses. On the basis of the criteria used, most of the veneers rated Alfa. After 7 years, the results of the clinical investigation regarding marginal adaptation and marginal discoloration revealed only 2.5% and 4.2% Bravo ratings, respectively, among the 119 initially placed veneers. Using the restoration as the statistical unit, the survival rate was 97.5%, with a high estimated success probability of 0.843 after 7 years. Using the patient as the statistical unit, the survival rate was 90.0% and the estimated success probability after 7 years was 0.824. Gingival response to the veneers was all in the satisfactory range. Porcelain laminate veneers offer a predictable and successful treatment modality giving a maximum preservation of sound tooth. The preparation, cementation, and finishing procedures adopted are considered key factors for the long-term success and aesthetical result of the veneer restorations.

  9. Porcelain crown with light-cured composite resin to repair all the clinical effect of anterior teeth defect%全瓷冠与光固化复合树脂修复前牙缺损的临床效果

    Institute of Scientific and Technical Information of China (English)

    姜守贵

    2016-01-01

    目的:探讨全瓷冠与光固化复合树脂修复前牙缺损的临床效果。方法选取我科2012年3月至2014年12月25例上前牙缺损的患者,对其36颗缺损的上前牙,按病例及年龄分类分为2组,全瓷冠修复组18颗患牙采用氧化锆全瓷冠修复,复合树脂修复组18颗患牙用卡瑞斯玛复合树脂充填修复。修复完成后检查修复体边缘密合性,外观及颜色,随访1年后复查,评价修复体的满意率。结果刚完成全瓷冠修复组的满意率94%,复合树脂组89%,差异无统计学意义(P>0.05)。1年后全瓷冠修复组的满意率89%,复合树脂组61%,差异有统计学意义(P 0.05). 1 years later the whole porcelain crown repair group, the satisfaction rate of 89%, the composite resin group 61%, the difference was statistically significant (P< 0.01).Conclusion the whole porcelain crown repair anterior tooth defect is a kind of ideal repair method.

  10. Application of light-cure resin-modified glass ionomer cement in orthodontic practice%光固化树脂加强型玻璃离子水门汀在正牙学实践中的作用

    Institute of Scientific and Technical Information of China (English)

    单丽华; 崔占琴; 沈庆华; 高琪; 邱志香

    2008-01-01

    BACKGROUND: Resin-modified glass ionomer (RMGI) cements have higher bond strength, especially can release fluoride. But there are fewer reports of the clinical application for the prevention of decalcification.OBJECTIVE: To test the benefit from using RMGI cement instead of a conventional composite resin in bracket bonding for patients with malocclusion, and observe bracket-failure rates and decalcification on enamel surfaces at pretreatment and at debonding.DESIGN: Observational and comparative trial.SETTING: The Second Hospital Affiliated to Hebei Medical University.PARTICIPANTS: Forty successive patients (358 teeth) with malocclusion admitted to the Department of Orthodontics in the Second Hospital Affiliated to Hebei Medical University, were selected for the study from July to August in 2002. All the patients (21 females and 19 males, mean age 16 years) had normal and complete anterior teeth, good oral hygiene. There were no obvious differences in bilateral teeth. Informed consents were obtained from all the subjects. The experiment was also approved by the ethical committee of the hospital. Experimental materials were RMGI adhesive (Fuji, GC, Japan, Lot 0005111) and composite resin cement (enamel adhesive of Beijing and Tianjin, Tianjin product, Lot 020402). Brackets produced from Hangzhou 3B and 37% phosphoric acid were used.METHODS: ①Bonding brackets: Subjects selected according to random procedure were divided into two groups, each with 20. GroupⅠ: The left buccal surfaces bonded with light-cure RMGI were etching for 30 seconds with 37% phosphoric acid, rinsed with water; the right buccal surfaces bonded with composite resin cement were etching for 60 seconds with 37% phosphoric acid, rinsed with water and dried; Group Ⅱ: After etching for 30 seconds with 37% phosphoric acid, the right buccal surfaces were rinsed with water and bonded brackets with light-cure RMGI. The left buccal surfaces were bonded brackets with composite resin cement after etching

  11. A Study on Effect of Surface Treatments on the Shear Bond Strength between Composite Resin and Acrylic Resin Denture Teeth.

    Science.gov (United States)

    Chatterjee, Nirmalya; Gupta, Tapas K; Banerjee, Ardhendu

    2011-03-01

    Visible light-cured composite resins have become popular in prosthetic dentistry for the replacement of fractured/debonded denture teeth, making composite denture teeth on partial denture metal frameworks, esthetic modification of denture teeth to harmonize with the characteristics of adjacent natural teeth, remodelling of worn occlusal surfaces of posterior denture teeth etc. However, the researches published on the bond strength between VLC composite resins and acrylic resin denture teeth is very limited. The purpose of this study is to investigate the effect of five different methods of surface treatments on acrylic resin teeth on the shear bond strength between light activated composite resin and acrylic resin denture teeth. Ninety cylindrical sticks of acrylic resin with denture teeth mounted atop were prepared. Various treatments were done upon the acrylic resin teeth surfaces. The samples were divided into six groups, containing 15 samples each. Over all the treated and untreated surfaces of all groups, light-cured composite resin was applied. The shear strengths were measured in a Universal Testing Machine using a knife-edge shear test. Data were analyzed using one way analysis of variance (ANOVA) and mean values were compared by the F test. Application of bonding agent with prior treatment of methyl methacrylate on the acrylic resin denture teeth resulted in maximum bond strength with composite resin.

  12. Posterior resin-based composite: review of the literature.

    Science.gov (United States)

    Burgess, J O; Walker, Richard; Davidson, J M

    2002-01-01

    The use of direct posterior resin-based composite has increased primarily due to patient esthetic desires and product improvements. Other factors (substantiated or not) contributing to increased use of resin-based composite are environmental and health concerns with dental amalgam. New visible light cured resin-based composite products are introduced yearly, as manufacturers continue to improve this tooth-colored restorative material. This paper will characterize current posterior resin-based composite materials (hybrid, microfill, flowable, and packable), review recent in vitro and clinical research, and recommend indications for these materials. In addition, the literature on compomers will be reviewed and recommendation made for their use. The data indicates that composite resin is a technique sensitive restorative material that can be used in large preparations if proper manipulation and isolation can be maintained. Compomers may also be used as an esthetic posterior restorative if proper isolation is provided.

  13. Review: Resin Composite Filling

    Science.gov (United States)

    Chan, Keith H. S.; Mai, Yanjie; Kim, Harry; Tong, Keith C. T.; Ng, Desmond; Hsiao, Jimmy C. M.

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin composite has aesthetic advantages over amalgam, one of the major disadvantage include polymerization shrinkage and future research is needed on reaction kinetics and viscoelastic behaviour to minimize shrinkage stress.

  14. A comparison of the accuracy of patterns processed from an inlay casting wax, an auto-polymerized resin and a light-cured resin pattern material

    Directory of Open Access Journals (Sweden)

    Praveen Rajagopal

    2012-01-01

    Conclusion: The resin pattern materials studied, undergo a significantly less dimensional change than the inlay waxes on prolonged storage. They would possibly be a better alternative to inlay wax in situations requiring high precision or when delayed investment (more than 1 h of patterns can be expected.

  15. 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

  16. 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

    2011-01-01

    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 fo

  17. Cytotoxicity of Light-Cured Dental Materials according to Different Sample Preparation Methods

    Science.gov (United States)

    Lee, Myung-Jin; Kim, Mi-Joo; Kwon, Jae-Sung; Lee, Sang-Bae; Kim, Kwang-Mahn

    2017-01-01

    Dental light-cured resins can undergo different degrees of polymerization when applied in vivo. When polymerization is incomplete, toxic monomers may be released into the oral cavity. The present study assessed the cytotoxicity of different materials, using sample preparation methods that mirror clinical conditions. Composite and bonding resins were used and divided into four groups according to sample preparation method: uncured; directly cured samples, which were cured after being placed on solidified agar; post-cured samples were polymerized before being placed on agar; and “removed unreacted layer” samples had their oxygen-inhibition layer removed after polymerization. Cytotoxicity was evaluated using an agar diffusion test, MTT assay, and confocal microscopy. Uncured samples were the most cytotoxic, while removed unreacted layer samples were the least cytotoxic (p cytotoxicity. Clinicians should remove unreacted monomers on the resin surface immediately after restoring teeth with light-curing resin to improve the restoration biocompatibility. PMID:28772647

  18. Relation between in-vitro wear and nanomechanical properties of commercial light-cured dental composites coated with surface sealants

    Directory of Open Access Journals (Sweden)

    Emanuel Santos Jr

    2013-01-01

    Full Text Available This work investigates the correlation between the in-vitro wear resistance and the nanomechanical properties of dental sealants commercially available. Mechanical properties, namely hardness (H and elastic modulus (E, were assessed by nanoindentation technique. The coated samples presented lower H and E values than the Z250 composite resin substrate. Such measurements were used to calculate H/E ratios. Wear tests were carried out in water by using a pin-on-plate apparatus. Scars formed on the samples were qualitatively examined by optical microscopy, while their wear depths were measured by contact profilometry. Based on the findings, an empirical correlation between the wear depths and H/E was obtained. A high H/E ratio was associated to surfaces with enhanced wear resistance. For the tribological conditions here employed, the H/E ratio could be, therefore, considered a useful parameter for ranking the in-vitro wear of dental sealants.

  19. Sorption kinetics of ethanol/water solution by dimethacrylate-based dental resins and resin composites.

    Science.gov (United States)

    Sideridou, Irini D; Achilias, Dimitris S; Karabela, Maria M

    2007-04-01

    In the present investigation the sorption-desorption kinetics of 75 vol % ethanol/water solution by dimethacrylate-based dental resins and resin composites was studied in detail. The resins examined were made by light-curing of bisphenol A glycol dimethacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), bisphenol A ethoxylated dimethacrylate (Bis-EMA), and mixtures of these monomers. The resin composites were prepared from two commercial light-cured restorative materials (Z100 MP and Filtek Z250), the resin matrix of which is based on copolymers of the above-mentioned monomers. Ethanol/water sorption/desorption was examined in both equilibrium and dynamic conditions in two adjacent sorption-desorption cycles. For all the materials studied, it was found that the amount of ethanol/water sorbed or desorbed was always larger than the corresponding one reported in literature in case of water immersion. It was also observed that the chemical structure of the monomers used for the preparation of the resins directly affects the amount of solvent sorbed or desorbed, as well as sorption kinetics, while desorption rate was nearly unaffected. In the case of composites studied, it seems that the sorption/desorption process is not influenced much by the presence of filler. Furthermore, diffusion coefficients calculated for the resins were larger than those of the composites and were always higher during desorption than during sorption. Finally, an interesting finding concerning the rate of ethanol/water sorption was that all resins and composites followed Fickian diffusion kinetics during almost the whole sorption curve; however, during desorption the experimental data were overestimated by the theoretical model. Instead, it was found that a dual diffusion-relaxation model was able to accurately predict experimental data during the whole desorption curve. Kinetic relaxation parameters, together with diffusion coefficients, are reported

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

    Directory of Open Access Journals (Sweden)

    Emel KARAMAN

    2014-08-01

    Full Text Available 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. Effectiveness analysis of light-curing resin esthetic restoration on defected incisor%前牙光固化美容修复的方法与效果分析

    Institute of Scientific and Technical Information of China (English)

    穆磊; 王巧云

    2014-01-01

    Objective:To explore the light-curing resin esthetic restoration effect on defected incisor. Methods:40 cases of defected incisor were randomly divided into treatment group and control group, with 20 cases. Control group was given routine orthodontic restoration therapy, and treatment group was given light-curing resin esthetic restoration therapy. Results:The satisfaction in treatment group was significantly higher than in control (100% vs. 80%,P<0.05). Pain relief and teeth functional recovery time in treatment group was significantly less than control (P<0.05). Conclusions:Light-curing resin esthetic restoration therapy in treatment of defected incisor increases satisfaction and promotes the recovery of teeth function.%目的:探讨前牙光固化美容修复的方法与效果。方法:前牙列缺损患者40例随机分为治疗组与对照组各20例。对照组给予传统正畸修复方法,治疗组给予基于光固化复合树脂的美容修复治疗。结果:治疗组的满意度明显高于对照组(100%vs.80%,P<0.05)。治疗组的疼痛缓解时间和牙齿功能恢复时间显著少于对照组(P<0.05)。结论:前牙光固化美容修复的应用能提高患者满意度,促进牙齿功能的恢复,值得推广应用。

  2. Light-cured glass ionomer versus resin reinforced glass ionomer for dental restoration%光固化和双重固化玻璃离子水门汀修复牙体的效果比较

    Institute of Scientific and Technical Information of China (English)

    刘艳; 陈晖

    2013-01-01

    BACKGROUND: Glass ionomer cement is a kind of new dental material. It has strong adhesiveness, low irritating, which is perfect to prevent dental caries. Currently, glass ionomer cement has been widely used in dental fil ing, adhesive, hole-lining, dentin hypersensitivity and temporary sealing. OBJECTIVE: To compare the repair effects of light-cured glass ionomer and resin reinforced glass ionomer on dental restoration. METHODS: Forty-eight dental caries patients were randomly divided into two groups: one group was repaired by light-cured glass ionomer and the other by resin reinforced glass ionomer. A fol ow-up of 6 months to 2 years was performed by comparison of integrityof the prosthesis, edge sealing, secondary caries and periodontal and endodontic lesions. RESULTS AND CONCLUSION: The fol ow-up of 6 months showed that the successful rate was 97% in the light-cured glass ionomer group and 99% in the resin reinforced glass ionomer group was 99%. There were no significant difference between the successful rates of the two groups after fol ow-up for 6 months (P > 0.05). The fol ow-up of 2 years showed that the successful rate was 74% in the light-cured glass ionomer group and 92% in the resin reinforced glass ionomer group, and a significant difference occurred between the two groups (P 0.05)。修复2年后复查,光固化玻璃离子水门汀组修复成功率为74%,双重固化离子水门汀组修复成功率为92%,两组比较差异有显著性意义(P <0.05)。表明双重固化玻璃离子水门汀材料修复体保持完整时间更长,边缘密闭性更好,继发龋和牙髓及牙周病变发生率更低,更适用于临床应用。

  3. The effects of restorative composite resins on the cytotoxicity of dentine bonding agents.

    Science.gov (United States)

    Kim, Kyunghwan; Son, Kyung Mi; Kwon, Ji Hyun; Lim, Bum-Soon; Yang, Hyeong-Cheol

    2013-01-01

    During restoration of damaged teeth in dental clinics, dentin bonding agents are usually overlaid with restorative resin composites. The purpose of this study was to investigate the effects of restorative resin composites on cytotoxicity of dentin bonding agents. Dentin bonding agents were placed on glass discs, pre-cured and uncured resin composite discs. Bonding agents on the glass discs and composite resins discs were light cured and used for agar overlay cytotoxicity testing. Dentin bonding agents on composite resin discs exhibited far less cytotoxicity than that on glass discs. The polymerization of resin composite increased the surface hardness and decreased the cytotoxicity of bonding agents. In conclusion, composite resins in dental restorations are expected to enhance the polymerization of dentin bonding agents and reduce the elution of resin monomers, resulting in the decrease of cytotoxicity.

  4. Effects of different curing methods and microleakage and degree of conversion of composite resin restorations

    OpenAIRE

    2003-01-01

    Statement of Problem: Recently, investigators have presented new methods to reduce polymerization shrinkage of composite resin restorations. It is claimed that more powerful light cure systems associated with a change in radiation patterns, lead to improved mechanical properties and reduced microleakage. Purpose: The aim of the present study was to evaluate the effects of two curing systems, known as Soft-Start, Pulse-Delay, on microleakage and degree of conversion of composite resin restorat...

  5. [Radiopacity of composite resins].

    Science.gov (United States)

    Tamburús, J R

    1990-01-01

    The author studied the radiopacity of six composite resins, submitted to radiographic examination in standardized conditions, only with kilovoltage variations. Along with resins it was radiographed an aluminium penetrometer, to compare their optical densities. The results showed that kilovoltagem variations interfered in optical densities of the resins, being more pronounced in 50-55, 55-60 and 60-65 kilovoltages. Despite this, the relations of optical densities as compared with that of penetrometer steps kept unaltered most fo the kilovoltages used.

  6. Biocompatibility of composite resins

    OpenAIRE

    Sayed Mostafa Mousavinasab

    2011-01-01

    Dental materials that are used in dentistry should be harmless to oral tissues, so they should not contain any leachable toxic and diffusible substances that can cause some side effects. Reports about probable biologic hazards, in relation to dental resins, have increased interest to this topic in dentists. The present paper reviews the articles published about biocompatibility of resin-restorative materials specially resin composites and monomers which are mainly based on Bis-GMA and concern...

  7. [Effects of composite resin materials on gingiva and pulp].

    Science.gov (United States)

    Yamaguchi, S; Ishikawa, I; Masunaga, H; Matsue, M; Matsue, I

    1989-09-01

    Composite resin materials are now widely used for dental therapy. The purpose of this study was to clarify the effect of composite resins on gingiva and pulp in case of application of them for temporally splint in periodontal treatment. 60 teeth in 6 female dogs ranging between 1 and 2 years of age with healty teeth and gingiva were divieded to 4 groups; (1) 12 teeth, controls; (2) 12 teeth, self-cured composite resin (Clearfil F II, CF II); (3) 18 teeth, light-cured resin (Belfel LX, BLX), curing time 20 sec. and (4) 18 teeth, BLX, 40 sec., and then 48 class V composite resins were restored supragingivally. The experimental procedure were carried out for 5 days and 30 days. Histopathological observations of 60 teeth inclusive of controls were made by applying to specimens with Hematoxylin eosin staining. For the materials and time periods in this study it was found that; 1. Light-cured composite resin was superior to self-cured composite resin on handlings. 2. There were no significant differences in periodontium between the experimentals (BLX, CF II) and controls in 5 days. At the 30 days the histologic score showed more gingivitis for the experimental teeth than for the controls (BLX-40 greater than BLX-20 greater than CF II greater than Cont.). 3. At 5 days hyperemia occurred in some cases of experimentals (both BLX and CF II). The appearance of predentin and changes of odontblastic layer were observed slightly in 30 days. But there were no significant differences between BLX and CF II. 4. The result suggested that applying to composite resin materials for temporally splint, both gingiva and pulp have to be protected.

  8. 光固化流体树脂窝沟封闭防龋疗效的评价%Clinical evaluation of light-cured flowable resin in preventing pit and fissure caries

    Institute of Scientific and Technical Information of China (English)

    韩静; 于洪波; 焦菲菲

    2016-01-01

    目的:比较光固化流体树脂与光固化窝沟封闭剂在儿童新生恒牙窝沟封闭预防龋坏的临床效果。方法临床选取150名7~10岁,双侧下颌第一恒磨牙无龋坏的儿童。每个儿童随机选取一侧作为试验组,用光固化流体树脂进行窝沟封闭,另一侧为对照组,用传统光固化窝沟封闭剂进行封闭。封闭治疗后6、12、24个月复查,检查封闭剂在牙面的保留率及龋病发生率,并进行统计学分析。结果2年后试验组光固化流体树脂脱落率和龋病发生率分别为7.80%和2.13%,对照组传统窝沟封闭剂的脱落率和龋病发生率分别为21.43%和7.09%,两组封闭剂脱落率和龋病发生率均有显著性差异(P<0.05)。结论光固化流体树脂在窝沟封闭预防龋坏治疗效果确切,值得临床推广。%Objective To compare the clinical effect of light-cured flowable resin and traditional light-cured pit and fissure sealant in preventing pit and fissure caries. Methods 150 children aged from 7 to 10 years with healthy permanent mandibular first molars were enrolled in this study. One side of permanent mandibular first molar was selected randomly as experimental group, which was sealed with light-cured flowable resin. The other side, as control group, was treated with traditional light-cured pit and fissure sealant. Pa-tients were followed up 6, 12 and 24 months later. The rate of resin loss and incidence of dental caries between two groups were com-pared by χ2 test. Results After two years, the rate of sealant loss and the incidence of caries of experimental group ( 7. 80%;2. 13%) were significantly lower than those of the control group(21. 43%;7. 09%) (P<0. 05). Conclusions Light-cured flowable resin is an effectively anticarious and reliable pit and fissure sealant.

  9. Repair bond strength of dual-cured resin composite core buildup materials.

    Science.gov (United States)

    El-Deeb, Heba A; Ghalab, Radwa M; Elsayed Akah, Mai M; Mobarak, Enas H

    2016-03-01

    The reparability of dual-cured resin composite core buildup materials using a light-cured one following one week or three months storage, prior to repair was evaluated. Two different dual-cured resin composites; Cosmecore™ DC automix and Clearfil™ DC automix core buildup materials and a light-cured nanofilled resin composite; Filtek™ Z350 XT were used. Substrate specimens were prepared (n = 12/each substrate material) and stored in artificial saliva at 37 °C either for one week or three months. Afterward, all specimens were ground flat, etched using Scotchbond™ phosphoric acid etchant and received Single Bond Universal adhesive system according to the manufacturers' instructions. The light-cured nanofilled resin composite (Filtek™ Z350 XT) was used as a repair material buildup. To determine the cohesive strength of each solid substrate material, additional specimens from each core material (n = 12) were prepared and stored for the same periods. Five sticks (0.8 ± 0.01 mm(2)) were obtained from each specimen (30 sticks/group) for microtensile bond strength (μTBS) testing. Modes of failure were also determined. Two-way ANOVA revealed a significant effect for the core materials but not for the storage periods or their interaction. After one week, dual-cured resin composite core buildup materials (Cosmecore™ DC and Clearfil™ DC) achieved significantly higher repair μTBS than the light-cured nanofilled resin composite (Filtek™ Z350 XT). However, Clearfil™ DC revealed the highest value, then Cosmecore™ DC and Filtek™ Z350 XT, following storage for 3-month. Repair strength values recovered 64-86% of the cohesive strengths of solid substrate materials. The predominant mode of failure was the mixed type. Dual-cured resin composite core buildup materials revealed acceptable repair bond strength values even after 3-month storage.

  10. Efficacy Observation of Light-cured Compounded Resin in the Treatment of Tooth Diseases%光固化复合树脂在牙体病治疗中的疗效观察

    Institute of Scientific and Technical Information of China (English)

    陈少华

    2015-01-01

    目的:观察不同部位的牙体缺损使用光固化复合树脂修复的临床疗效,并探讨影响疗效的因素。方法:采用光固化复合树脂修复不同部位的64颗牙缺损,并随访3、5、8年,对临床修复效果及影响因素进行分析。结果:64颗牙缺损修复后随访3、5、8年,治疗成功率分别为成功率分别为90.63%、81.25%及68.75%,失败病例主要表现修复体松动脱落、折裂、变色、继发龋、患者出现牙髓炎和根尖周炎。结论:光固化复合树脂治疗不同部位的牙体病成功率较高,远期疗效有待进一步提高。%Objective:To observe the clinical effects of light-cured compounded resin in the treatment of tooth defect in different parts and to discuss the factors that affect efficacy.Method:64 defected teeth in different parts were given the light-cured compounded resin to restore. The patients were then followed up after three, five and eight years of the treatment.Finally,the effectiveness and elements affecting clinical restoration during the treatment were analyzed. Result:According to the interviews of 64 defected teeth after three,five and eight years of the treatment, the success rate was respectively 90.63%,81.25% and 68.75%.Failure cases included abrasion, detachment of fillings, secondary caries, color change and stain.Conclusion:The success rate of light-cured compounded resin in the treatment of tooth defect in different parts is high, but in the long term the efficacy remains to be improved.

  11. Biocompatibility of composite resins

    Directory of Open Access Journals (Sweden)

    Sayed Mostafa Mousavinasab

    2011-01-01

    Full Text Available Dental materials that are used in dentistry should be harmless to oral tissues, so they should not contain any leachable toxic and diffusible substances that can cause some side effects. Reports about probable biologic hazards, in relation to dental resins, have increased interest to this topic in dentists. The present paper reviews the articles published about biocompatibility of resin-restorative materials specially resin composites and monomers which are mainly based on Bis-GMA and concerns about their degradation and substances which may be segregated into oral cavity.

  12. Battery Charge Affects the Stability of Light Intensity from Light-emitting Diode Light-curing Units.

    Science.gov (United States)

    Tongtaksin, A; Leevailoj, C

    This study investigated the influence of battery charge levels on the stability of light-emitting diode (LED) curing-light intensity by measuring the intensity from fully charged through fully discharged batteries. The microhardness of resin composites polymerized by the light-curing units at various battery charge levels was measured. The light intensities of seven fully charged battery LED light-curing units-1) LY-A180, 2) Bluephase, 3) Woodpecker, 4) Demi Plus, 5) Saab II, 6) Elipar S10, and 7) MiniLED-were measured with a radiometer (Kerr) after every 10 uses (20 seconds per use) until the battery was discharged. Ten 2-mm-thick cylindrical specimens of A3 shade nanofilled resin composite (PREMISE, Kerr) were prepared per LED light-curing unit group. Each specimen was irradiated by the fully charged light-curing unit for 20 seconds. The LED light-curing units were then used until the battery charge fell to 50%. Specimens were prepared again as described above. This was repeated again when the light-curing units' battery charge fell to 25% and when the light intensity had decreased to 400 mW/cm(2). The top/bottom surface Knoop hardness ratios of the specimens were determined. The microhardness data were analyzed by one-way analysis of variance with Tukey test at a significance level of 0.05. The Pearson correlation coefficient was used to determine significant correlations between surface hardness and light intensity. We found that the light intensities of the Bluephase, Demi Plus, and Elipar S10 units were stable. The intensity of the MiniLED unit decreased slightly; however, it remained above 400 mW/cm(2). In contrast, the intensities of the LY-A180, Woodpecker, and Saab II units decreased below 400 mW/cm(2). There was also a significant decrease in the surface microhardnesses of the resin composite specimens treated with MiniLED, LY-A180, Woodpecker, and Saab II. In conclusion, the light intensity of several LED light-curing units decreased as the battery was

  13. Acceleration of curing of resin composite at the bottom surface using slow-start curing methods.

    Science.gov (United States)

    Yoshikawa, Takako; Morigami, Makoto; Sadr, Alireza; Tagami, Junji

    2013-01-01

    The aim of this study was to evaluate the effect of two slow-start curing methods on acceleration of the curing of resin composite specimens at the bottom surface. The light-cured resin composite was polymerized using one of three curing techniques: (1) 600 mW/cm(2) for 60 s, (2) 270 mW/cm(2) for 10 s+0-s interval+600 mW/cm(2) for 50 s, and (3) 270 mW/cm(2) for 10 s+5-s interval+600 mW/cm(2) for 50 s. After light curing, Knoop hardness number was measured at the top and bottom surfaces of the resin specimens. The slow-start curing method with the 5-s interval caused greater acceleration of curing of the resin composite at the bottom surface of the specimens than the slow-start curing method with the 0-s interval. The light-cured resin composite, which had increased contrast ratios during polymerization, showed acceleration of curing at the bottom surface.

  14. 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

    Objectives: 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. Materials and Methods: 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). Results: 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. Conclusion: 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. PMID:27843507

  15. 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.

  16. Retention of a Flowable Composite Resin in Comparison to a Conventional Resin-Based Sealant: One-year Follow-up

    OpenAIRE

    N. Tadayon; B. Malekafzali; M.Jafarzadeh; Fallahi, S.

    2010-01-01

    Objective: Long-term retention of pit and fissure sealants is crucial for their success. This clinical study evaluated the retention rate of a flowable composite resin (Filtek Supreme XT Flowable Restorative) compared to a conventional resin-based sealant (Concise Light Cure White Sealant) over 12 months. Materials and Methods: Forty subjects aged 6 to 9 years were included in the study. Using a half-mouth design, a total of 80 first permanent molars were sealed with conventional fissure seal...

  17. Vickers Hardness of Composite Resins Cured with LED and QTH Units

    Directory of Open Access Journals (Sweden)

    Alaghemand H

    2016-03-01

    Full Text Available Statement of Problem: One of the factors affecting the degree of polymerization of light-cured composites is the type of light-curing unit used. In addition, physicomechanical properties of the composite resins depend on the degree of conversion and polymerization. Objectives: Since the type of initiator in new composite resins is not explained by manufacturers, this study is an attempt to compare the depth of hardening, with two LED and QTH light-curing units. Materials and Methods: Fifteen samples prepared from Gradia Direct and Filtek Z250, both of which being universal, were cured with QTH (Astralis 7 and LED (Bluephase C8 light-curing units. All the samples were molded in polyester resin and cut from the middle by a disk. The hardness of the cut area was evaluated at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5 and 4-mm depth intervals and also at the same interval as the width of the sample, with Vickers hardness machine, while the samples were placed in a darkroom. Data were statistically analyzed using one-way ANOVA, two-way ANOVA, t-test and post Hoc Tukey’s tests in SPSS, version 16. Results: Filtek Z250 was harder than Gradia Direct at all the depth with both light-curing units. The hardness of Filtek Z250 sample cured with Astralis 7 was higher than that cured with LED, but with Gradia Direct the LED unit resulted in higher hardness. Curing depth was not significantly different between the groups (p = 0.109. Conclusions: Vickers hardness number for both composites used in this study is in an acceptable range for clinical implications. The composites’ composition is important to be considered for selection of light unit. Based on the findings of the present study, LED did not present more curing depth compared with QTH.

  18. The influence of lining techniques on the marginal seal of Class II composite resin restorations.

    Science.gov (United States)

    Blixt, M; Coli, P

    1993-03-01

    Various sealing techniques using a light-curing dental adhesive (Scotchbond 2) and bulk application of a light-curing resin-bonded ceramic were examined in 203 Class II cavities. Different pretreatment procedures and lining materials were used, and in one series resin impregnation of the contraction gap was included. The presence of gaps or leakage was disclosed either by a dye or a fluorescent resin penetration technique. In many restorations, Scotchbond 2 and a light-curing glass-ionomer lining did not prevent gap formation at the cervical wall. The gap usually occurred between the liner and the dentin, with dye penetration into the dentin. Three liners, one containing polytrifluorethylene sodium fluoride and calcium fluoride, one containing polyamide resin, and one containing calcium hydroxide, did not prevent dye penetration to the dentin at all; good dentinal protection was frequently observed, however, in cavities treated with a hydrophilic shellac film prior to placement of a polystyrene liner. The best results were observed when dentinal treatment with this lining system was followed by resin impregnation of the contraction gap after the composite resin had set.

  19. Cytotoxicity of dental resin composites: an in vitro evaluation.

    Science.gov (United States)

    Ausiello, Pietro; Cassese, Angela; Miele, Claudia; Beguinot, Francesco; Garcia-Godoy, Franklin; Di Jeso, Bruno; Ulianich, Luca

    2013-06-01

    Resin-based dental restorative materials release residual monomers that may affect the vitality of pulp cells. The purpose of this study was to evaluate the cytotoxic effect of two light-cured restorative materials with and without bis-GMA resin, respectively (Clearfil Majesty Posterior and Clearfil Majesty Flow) and a self-curing one (Clearfil DC Core Automix) when applied to the fibroblast cell line NIH-3T3. Samples of the materials were light-cured and placed directly in contact to cells for 24, 48, 72 and 96 h. Cytotoxicity was evaluated by measuring cell death by flow cytometry, cell proliferation by proliferation curves analysis and morphological changes by optical microscopy analysis. All the composite materials tested caused a decrease in cell proliferation, albeit at different degrees. However, only Clearfil DC Core Automix induced cell death, very likely by increasing apoptosis. Morphological alteration of treated cells was also evident, particularly in the Clearfil DC Core Automix-treated cells. The different cytotoxic effects of dental composites should be considered when selecting an appropriate resin-based dental restorative material for operative restorations.

  20. Bond strength of a light-cured and two auto-cured glass ionomer liners.

    Science.gov (United States)

    Holtan, J R; Nystrom, G P; Olin, P S; Rudney, J; Douglas, W H

    1990-10-01

    Ninety-nine extracted human molar teeth were used in this study comparing the shear bond strengths on dentine of one light-cured and two auto-cured polyalkenoate (glass ionomer) cements. Bond strength can be influenced by differences in tooth structure. A balanced-incomplete block design (Hull and Nie, 1981) was used to reduce variation attributable to such differences. Cements were applied to paired dentine surfaces in combinations such that 66 tooth sides were treated with each material. A light-cured dentinal adhesive and composite resin restorative material were then placed and shear bond strength testing was conducted exactly 24 h after the completion of each specimen. Mean forces (MPa) for the three materials were compared using an appropriate analysis of variance model (balanced-incomplete-blocks) The shear bond strengths (MPa) of the light-cured liner (Espe, Seefeld/Oberbay, FRG) was 4.71 +/- 1.16. Vitrabond showed the greatest variance of all three materials tested, however this material's average bond strength was greater than the maximum achieved for the other materials. Student-Newman-Keuls comparison of means showed that all cements differed significantly from each other (alpha = 0.05). It is concluded that the light-cured glass ionomer liner exhibited significantly better shear bond strength performance than the two auto-cured glass ionomers tested.

  1. 光固化树脂分层充填技术的应用现状%Application of layered filling technology with light cured resin

    Institute of Scientific and Technical Information of China (English)

    赵奇; 吴艳

    2012-01-01

    Layered resin filling technology is based on resin curing shrinkage characteristics and aesthetic effects. This article, from several aspects such as curing light of cured resin, aesthetic effect needs, reducing shrinkage and shrinkage tension, wear resistance and intensity, gives a detailed description.%分层树脂充填技术是基于树脂的固化收缩特性和美学需要所采取的操作步骤,本文从光固化灯的树脂固化、美学效果的需要、减少收缩率和收缩张力、耐磨性及强度几个方面作一描述.

  2. Depth of cure of dental composites submitted to different light-curing modes Profundidade de polimerização de compósitos restauradores submetidos a diferentes métodos de fotoativação

    Directory of Open Access Journals (Sweden)

    Raphael Vieira Monte Alto

    2006-04-01

    Full Text Available OBJECTIVE: This study evaluated the depth of cure of five dental composites submitted to different light-curing modes. MATERIAL AND METHODS: Canal-shaped cavities with 5mm of length were prepared on the buccal surfaces of extracted third molars, and restored using P-60, A-110, Admira, Z-250 and Supreme resin composites. Materials were light-cured from the top, according to three modes (Group 1- Conventional (C: 500 mW/cm² / 40 s; Group 2 - Soft-Start (SS: 250 mW/cm²/ 20 s + 500 mW/cm²/ 20 s + 500 mW/cm²/ 10 s and Group 3 - LED: 250 mW/cm²/ 40 s. After that, cavity longitudinal surfaces were polished and marked with a millimeter scale of 4mm of length. Depth of cure was evaluated by means of Knoop hardness number (KHN, so that five indentations were performed at each millimeter. Original data were submitted to three-way ANOVA and Fisher's LSD test (alpha = 0.01. RESULTS: All materials presented a significant reduction on KHN from first to third millimeter. Regarding depth of cure, the results obtained for Conventional and Soft-Start modes were similar, but statistically superiors to those found for group 3 (LED. CONCLUSION: This performance may be related to the differences among energy densities obtained with different light-curing modes.OBJETVO: Este estudo avaliou a profundidade de polimerização de cinco compósitos fotopolimerizáveis submetidos a diferentes métodos de fotoativação. MATERIAL E MÉTODO: Cavidades em forma de canaleta com 5 mm de comprimento, preparadas nas faces vestibulares de terceiros molares, foram restauradas com os compósitos P-60, A-110, Admira, Z-250 e Supreme. Os materiais foram fotoativados pelo topo das cavidades com três técnicas (Grupo 1 - Convencional (C: 500 mW / cm² / 40 s; Grupo 2 - Soft-Start (SS: 250 mW / cm² / 20 s + 500 mW / cm² / 20 s + 500 mW / cm² / 10 s e Grupo 3 - LED: 250 mW / cm² / 40 s. Após a fotoativação, as superfícies longitudinais dos materiais foram polidas e marcadas

  3. Effect of temperature, curing time, and filler composition on surface microhardness of composite resins

    OpenAIRE

    Dimitrios Dionysopoulos; Constantinos Papadopoulos; Eugenia Koliniotou-Koumpia

    2015-01-01

    Aim: The aim of this study was to evaluate the microhardness of two composite resins when subjected to three different temperatures and three different light-curing times. Materials and Methods: Two composites were used; Filtek Z250 and Grandio. Three different temperatures (23, 37, and 55 o C) were used, utilizing a composite warmer. The heated samples were immediately injected into cylindrical molds (6 mm × 2 mm) and the top surface of the specimens was polymerized for 10, 20, and 40 se...

  4. 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

  5. Influence of composite restorative materials and light-curing units on diametrical tensile strength Influência do material restaurador e de aparelhos fotoativadores na resistência à tração diametral

    Directory of Open Access Journals (Sweden)

    Maria Cecília Caldas Giorgi Tolosa

    2005-06-01

    Full Text Available The aim of this study was to evaluate the diametrical tensile strength (DTS of three light-curing photo-activated composites with two different light curing units (LCU. Three types of dental restorative composites were used in this study: micro filled A110 (3M Espe; P60 (3M Espe for posterior restorations, and micro-hybrid Charisma (Heraeus-Kulzer. The two LCUs were: halogen light (HAL (Degulux, Degussa and blue light emitting diode (LED (Ultrablue, DMC. Resin composite specimens were inserted incrementally into a Teflon split mold meas-uring 3 mm in depth and 6 mm in internal diameter, and cured using either LCU (n = 10. Specimens were placed into a dark bottle containing distilled water at 37°C for 7 days. DTS tests were performed in a Universal Testing Machine (0.5 mm/min. Data were submitted to two-way ANOVA and Tukey's test. Results were (MPa: A110/HAL: 276.50 ± 62.94ª; A110/LED: 306.01 ± 65.16ª; P60/HAL: 568.29 ± 60.77b and P60/LED: 543.01 ± 83.65b; Charisma/HAL: 430.94 ± 67.28c; Charisma/LED: 435.52 ± 105.12c. Results suggested that no significant difference in DTS was obtained with LCUs for the same composite. However, resin composite restorative materials presented different DTS.O objetivo deste estudo foi avaliar a resistência à tração diametral (DTS de três compósitos fotoativados com dois aparelhos de fotoativação (LCU. Os compósitos utilizados neste estudo foram: resina de micropartículas A110 (3M Espe; P60 (3M Espe, indicada para restaurações posteriores, e micro-híbrida Charisma (Heraeus-Kulzer. As fontes de luz foram: halógena (HAL - Degulux (Degussa e luz emitida por diodos (LED - Ultrablue (DMC. As amostras foram confeccionadas através de dois incrementos inseridos em uma matriz de Teflon bipartida medindo 3 mm de profundidade e 6 mm de diâmetro interno e foram fotoativadas pelas LCUs (n = 10. As amostras foram armazenadas dentro de recipientes escuros contendo água destilada a 37°C por 7 dias. O

  6. Effect of Dental Chair Light on Enamel Bonding of Orthodontic Brackets Using Light Cure Based Adhesive System: An In-Vitro Study

    Science.gov (United States)

    Tiwari, Anil; Shyagali, Tarulatha; Kohli, Sarvraj; Joshi, Rishi; Gupta, Abhishek; Tiwari, Rana

    2016-01-01

    Aim: The aim of this in vitro study was to evaluate the influence of the Dental chair light on the bond strength of light cured composite resin. Materials and Methods: Sixty therapeutically extracted human premolar teeth were randomly allocated to two groups of 30 specimens each. In both groups light cured composite resin (Transbond XT) and MBT premolar metal brackets (3M Unitek) was used to bond brackets. In group I and II light curing was done using Light-emitting diode light curing units without and with the dental chair light respectively. After bonding, all samples were stored in distilled water at room temperature for 24 hours and subsequently tested for shear bond strength and Adhesive Remnant Index (ARI) scores. Data was subjected to Mann Whitney U statistical test. Results: Results indicated that there was significantly higher shear bond strength (7.71 ± 1.90) for the Group II (composite cured with LED and dental chair light) compared with Group I (composite cured with LED LCU only) (5.74 ± 1.13).the obtained difference was statistically significant. There was no statistical significant difference between ARI scores in between the groups. Conclusions: light cure bonding with dental chair light switched on will produce greater bond strength than the conventional bonding. However, the ARI score were similar to both the groups. It is advised that the inexperienced orthodontist should always switch off the dental chair light while bonding for enough working time during the bracket placement. PMID:28077886

  7. µCT-3D visualization analysis of resin composite polymerization and dye penetration test of composite adaptation.

    Science.gov (United States)

    Yoshikawa, Takako; Sadr, Alireza; Tagami, Junji

    2017-08-25

    This study evaluated the effects of the light curing methods and resin composite composition on composite polymerization contraction behavior and resin composite adaptation to the cavity wall using μCT-3D visualization analysis and dye penetration test. Cylindrical cavities were restored using Clearfil tri-S Bond ND Quick adhesive and filled with Clearfil AP-X or Clearfil Photo Bright composite. The composites were cured using the conventional or the slow-start curing method. The light-cured resin composite, which had increased contrast ratio during polymerization, improved adaptation to the cavity wall using the slow-start curing method. In the μCT-3D visualization method, the slow-start curing method reduced polymerization shrinkage volume of resin composite restoration to half of that produced by the conventional curing method in the cavity with adhesive for both composites. Moreover, μCT-3D visualization method can be used to detect and analyze resin composite polymerization contraction behavior and shrinkage volume as 3D image in the cavity.

  8. Indirect resin composites

    Directory of Open Access Journals (Sweden)

    Nandini Suresh

    2010-01-01

    Full Text Available Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses. Indirect composites offer an esthetic alternative to ceramics for posterior teeth. This review article focuses on the material aspect of the newer generation of composites. This review was based on a PubMed database search which we limited to peer-reviewed articles in English that were published between 1990 and 2010 in dental journals. The key words used were ′indirect resin composites,′ composite inlays,′ and ′fiber-reinforced composites.′

  9. Comparison of Shear Bond Strength between Composite Resin and Porcelain Using Different Bonding Systems

    Directory of Open Access Journals (Sweden)

    E.Yassini

    2005-03-01

    Full Text Available Statement of Problem: Ceramics as in ceramo-metallic and all ceramic tooth restorations have grown popular owing to their high tissue compatibility and esthetic advantages. Such restorations have the capability to deliver valuable services over a long period of time; however, failures under intraoral conditions are not unanticipated.Purpose: The purpose of this in-vitro study was to investigate the shear bond strength of composite resin to porcelain using different bonding system materials.Materials and Methods: In this experimental study forty porcelain blocks were prepared and randomly divided into four equal groups. The porcelain surfaces were then etched with HF for 2 minutes, washed with water for 2 minutes and treated with a silane layer. The silane treated porcelain surfaces were left for one minute and then the specimens were bonded to composite resin as follow:Group 1 (control group, hybrid composite Z100 was applied and light cured from four directions for 20 seconds. Group 2, flowable composite was applied and light cured for 20 seconds. Group 3, unfilled resin was used and photo cured for 20 seconds. Group 4,(Dentin bonding agent adhesive resin was used followed by 20 seconds photo curing.Hybrid composite resin Z100 was subsequently applied on all porcelain surfaces of groups 2, 3 and 4, and light cured for 20 seconds from four directions. Specimens were then subjected to thermocycling 1000 times. Shear bond strength was determined by a Universal testing machine. The data obtained was subjected to a one-way ANOVA test.Results: The results indicate that there is a statistically significant difference between adhesive group and the other three groups of hybrid, flowable and unfilled resin (P<0.05.Conclusion: The results from this study showed that the shear bond strength of composite resin to porcelain was significantly higher for porcelain bonded surfaces using a dentin bonding agent than that of other materials tested.

  10. 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.

  11. 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.

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

    Science.gov (United States)

    Samimi, Pooran; Alizadeh, Mehdi; Shirban, Farinaz; Davoodi, Amin; Khoroushi, Maryam

    2016-01-01

    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. 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. 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.

  13. 光固化流体树脂与非创伤性充填窝沟封闭成本效果评价%Cost-effectiveness evaluation of pit and fissure sealant with light-cured flowable resin and ART

    Institute of Scientific and Technical Information of China (English)

    曹慧珍; 束陈斌; 汪隼

    2011-01-01

    Objective To compare the difference of the cost and retention rate between pit and fissure sealants light-cured flowable resin and ART. Methods 267 children aged 7 ~ 10 from two primary schools were selected for this study. Each of them had at least two caries-free and deep fissure first molars. One first molar was sealed with ART techniques and the other molar were sealed with light-cured flowable resin. The portable dental chair was used to absorb saliva and cotton rolls were applied for moisture control. The number of cotton rolls and time cost in the operation were recorded. One year later, the retention rates of the two materials were checked by two dentists using explorer. All procedures were performed in primary schools. Results It took 3. 18 minutes for one tooth to be sealed with ART and 3.32 minutes with flowable resin ( P 0.05 ). The retention rate of the light-cured flowable resin group was higher compared to ART group (P < 0.01). Conclusions Both flowable resin composites and ART can prevent caries. They're recommended to be performed in schools.%目的 比较光固化流体树脂与非创伤性充填(ART)封闭技术在实施窝沟封闭方面防龋成本及保留率的差异.方法 选择上海市两所小学7~10岁儿童267名,口腔内至少有2个第一恒磨牙无龋及有较深窝沟.随机选择每名儿童第一恒磨牙一侧用ART技术进行窝沟封闭,其它的第一恒磨牙用光固化流体树脂进行窝沟封闭,使用便携式牙科椅吸取唾液,并用棉卷隔湿.两种方法在操作时记录每个牙封闭所用去的棉卷数和操作时间.1年后检查两种材料在牙面上的保留情况.所有操作均在学校内施行,检查由两名医师使用镰形探针进行检查.结果 使用ART封闭技术进行窝沟封闭操作时间每牙需3.18 min,而光固化流体树脂组需3.32 min(P<0.01),所用棉花卷数和重复次数无差异(P>0.05).在封闭剂的保留率方面,光固化流体树脂

  14. The effect of resin shades on microhardness, polymerization shrinkage, and color change of dental composite resins.

    Science.gov (United States)

    Jeong, Tae-Sung; Kang, Ho-Seung; Kim, Sung-Ki; Kim, Shin; Kim, Hyung-Il; Kwon, Yong Hoon

    2009-07-01

    The present study sought to evaluate the effect of resin shades on the degree of the polymerization. To this end, response variables affected by the degree of polymerization were examined in this study - namely, microhardness, polymerization shrinkage, and color change. Two commercial composite resins of four different shades were employed in this study: shades A3, A3.5, B3, and C3 of Z250 (Z2) and shades A3, A3.5, B3, and B4 of Solitaire 2 (S2). After light curing, the reflectance/absorbance, microhardness, polymerization shrinkage, and color change of the specimens were measured. On reflectance and absorbance, Z2 and S2 showed similar distribution curves regardless of the resin shade, with shade A3.5 of Z2 and shade A3 of S2 exhibiting the lowest/highest distributions. Similarly for attenuation coefficient and microhardness, the lowest/highest values were exhibited by shade A3.5 of Z2 and shade A3 of S2. On polymerization shrinkage, no statistically significant differences were observed among the different shades of Z2. Similarly for color change, Z2 specimens exhibited only a slight (DeltaE*=0.5-0.9) color change after immersion in distilled water for 10 days, except for shades A3 and A3.5. Taken together, results of the present study suggested that the degree of polymerization of the tested composite resins was minimally affected by resin shade.

  15. 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...... spectroscopy (FTIR). Wear was assessed by a three-body test. Data were submitted to Levene's test, one and three-way ANOVA, and Tukey HSD test (alpha = 0.05). Results: Immersion in ethanol, curing mode, and material all had significant effects on Wallace hardness. After ethanol storage, resin composites...

  16. Curing efficiency of various types of light-curing units.

    Science.gov (United States)

    Rahiotis, Chris; Kakaboura, Afrodite; Loukidis, Michalis; Vougiouklakis, George

    2004-02-01

    This study compared monomer conversion (DC), the per cent linear polymerization shrinkage (%LS), the wall-to-wall contraction pattern (per cent of peripheral opening, %DM, and maximal marginal gap, MG) and depth of cure (DOC), of a hybrid resin composite (Spectrum TPH) exposed to different types of light-curing units and exposure modes (Virtuoso-PAC, Elipar TriLight-QTH, and FreeLight-LED). The QTH and LED units were used in two curing modes: the exponential ramp and the continuous output modes. Monomer conversion was investigated by micro Multiple Internal Reflection (MIR)-Fourier-transform infrared (FTIR) spectroscopy and %LS was measured by the deflective disc method. The wall-to-wall contraction method used a cylindrical cavity model in extracted human teeth. The per cent debonded margins relative to the cavity periphery (%DM) and the width of maximum gap (MG) was evaluated. The DOC was determined using Vickers microhardness measurements (200 g load, 20 s) at the top surface (H0), at 2 mm (H2) and at 4 mm (H4) depths, and the results expressed as H2/H0 and H4/H0 ratios. Significantly lower %DC and %LS values were provided by PAC and LED units. No differences were found in %DM among the curing units and PAC exhibited the highest MG. No significant differences were noted among light-curing groups in terms of H2/H0 microhardness values. The QTH, operated in exponential mode, resulted in the highest H4/H0 value. The exponential mode of the QTH demonstrated superior performance for the total of the characteristics evaluated.

  17. Repair of dental resin-based composites.

    Science.gov (United States)

    Baur, Veronika; Ilie, Nicoleta

    2013-03-01

    The study analyzed the reparability and compatibility of light-curing resin-based composites (RBCs) of the categories "microhybrid," "nanohybrid," and "packable." Six RBCs with different matrix and filler formulation--purely methacrylate-based composites (MBCs), ormocer-based composites (OBCs), and silorane-based composites (SBCs)--were used for the specimens. Every material was combined with itself and with the other five RBCs, resulting in a total of 36 combination groups (n = 20). The specimens were polymerized, aged for 8 weeks in distilled water at 37 °C, and then repaired by means of a repair kit. Shear bond strength and fracture mode were measured after aging of the specimens, undergoing storage for 24 h in distilled water at 37 °C followed by thermocycling (5,000 cycles, 5-55 °C) and an additional 4-week storage in distilled water at 37 °C. Data were statistically analyzed using ANOVA with TUKEY HSD post hoc test (α = 0.05). On average, the OBC Admira reached the highest value as a substrate material (30.41 MPa), and the SBC Filtek Silorane reached the lowest value (8.14 MPa). Filtek Silorane was identified as the repair material with the highest bond strength value (28.70 MPa), while a packable composite reached the lowest bond strength value (15.55 MPa). The analysis of the break modes showed that adhesive breaks are typical when strength is at its lowest (6.27 MPa). A large number of cohesive fractures are conspicuous when identical materials are used for repair, except Filtek Silorane (2 % cohesive fractures). The study demonstrated that the effect of the different materials on bond strength varies strongly, depending on whether the material is used as filling or as repair material. It is generally advisable but not compulsory to combine identical RBCs.

  18. Secondary caries formation in vitro around glass ionomer-lined amalgam and composite restorations.

    Science.gov (United States)

    Dionysopoulos, P; Kotsanos, N; Papadogianis, Y

    1996-08-01

    The aim of this in vitro secondary caries study was to examine the glass-ionomer liner's effect on wall-lesion inhibition when a conventional and a light-cured glass ionomer liner was placed under amalgam and composite resin restorations. Class V preparations in extracted upper premolars were used and ten restorations were used for each of the following groups: (i) two layers of copal varnish and amalgam; (ii) conventional glass-ionomer and amalgam; (iii) light-cured glass-ionomer and amalgam; (iv) bonding agent and light-cured composite resin; (v) conventional glass-ionomer, bonding agent and light-cured composite resin; (vi) light-cured glass-ionomer, extended 0.3 mm short of the enamel margin bonding agent and light-cured composite resin; and (vii) light-cured glass-ionomer, extended 1 mm short of the enamel margin, bonding agent and light-cured composite resin. The teeth were thermocycled and artificial caries were created using an acid-gel. The results of this study showed that artificial recurrent caries can be reduced significantly (P amalgam restorations. The results also showed that when the light-cured glass-ionomer liner was placed 0.3 mm from the cavosurface margin under composite resin restoration, the artificial recurrent caries reduced significantly (P < 0.05).

  19. Polymerization shrinkage, flexural and compression properties of low-shrinkage dental resin composites.

    Science.gov (United States)

    Park, Jeong-Kil; Lee, Geun-Ho; Kim, Jong-Hwa; Park, Mi-Gyoung; Ko, Ching-Chang; Kim, Hyung-Il; Kwon, Yong Hoon

    2014-01-01

    This study evaluated the polymerization shrinkage, flexural and compressive properties of low-shrinkage resin composites. For the study, four methacrylate-based and one silorane-based resin composites were light cured using three different light-curing units (LCUs) and their polymerization shrinkage, flexural (strength (FS) and modulus (FM)) and compressive (strength (CS) and modulus (CM)) properties were evaluated. Data were statistically analyzed using ANOVA and a post-hoc Tukey test. The polymerization shrinkage ranged approximately 7.6-14.2 μm for 2-mm thick specimens depending on the resin product and LCU. Filtek LS showed the least shrinkage while the rest shrank approximately 13.2-14.2 μm. However, Filtek LS showed the greatest shrinkage difference for the used LCUs. FS and CS of the tested specimens ranged 96.2-152.1 MPa and 239.2-288.4 MPa, respectively, depending on the resin product and LCU. The highest and lowest FS and FM were recorded for the methacrylate-based resin composites. Among the specimens, Filtek LS showed the lowest CS and CM.

  20. 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

  1. Temperature rise during polymerization of different cavity liners and composite resins

    Directory of Open Access Journals (Sweden)

    Ozcan Karatas

    2015-01-01

    Full Text Available Objective: The purpose of this study was to evaluate the thermal insulating properties of different light curing cavity liners and composite resins during light emitting diode (LED curing. Materials and Methods: Sixty-four dentin discs, 1 mm thick and 8 mm in diameter, were prepared. Specimens were divided into four groups. Calcium hydroxide (Ca[OH] 2 , resin-modified glass ionomer cement, flowable composite and adhesive systems were applied to dentin discs according to the manufacturers′ instructions. The rise in temperature during polymerization with a LED curing unit (LCU was measured using a K-type thermocouple connected to a data logger. Subsequently, all specimens were randomly divided into one of two groups. A silorane-based composite resin and a methacrylate-based composite resin were applied to the specimens. Temperature rise during polymerization of composite resins with LCU were then measured again. Data were analyzed using one-way ANOVA and post hoc Tukey analyses. Results: There were significant differences in temperature rise among the liners, adhesives, and composite resins (P < 0.05. Silorane-based composite resin exhibited significantly greater temperature rises than methacrylate-based resin (P < 0.05. The smallest temperature rises were observed in Ca(OH 2 specimens. Conclusion: Thermal insulating properties of different restorative materials are important factors in pulp health. Bonding agents alone are not sufficient to protect pulp from thermal stimuli throughout curing.

  2. Fatigue resistance and failure mode of adhesively restored custom metal-composite resin premolar implant abutments.

    Science.gov (United States)

    Boff, Luís Leonildo; Oderich, Elisa; Cardoso, Antônio Carlos; Magne, Pascal

    2014-01-01

    To evaluate the fatigue resistance and failure mode of composite resin and porcelain onlays and crowns bonded to premolar custom metal-composite resin premolar implant abutments. Sixty composite resin mesostructures were fabricated with computer assistance with two preparation designs (crown vs onlay) and bonded to a metal implant abutment. Following insertion into an implant with a tapered abutment interface (Titamax CM), each metal-composite resin abutment was restored with either composite resin (Paradigm MZ100) or ceramic (Paradigm C) (n = 15) and attached with adhesive resin (Optibond FL) and a preheated light-curing composite resin (Filtek Z100). Cyclic isometric chewing (5 Hz) was then simulated, starting with 5,000 cycles at a load of 50 N, followed by stages of 200, 400, 600, 800, 1,000, 1,200, and 1,400 N (25,000 cycles each). Samples were loaded until fracture or to a maximum of 180,000 cycles. The four groups were compared using life table survival analysis (log-rank test). Previously published data using zirconia abutments of the same design were included for comparison. Paradigm C and MZ100 specimens fractured at average loads of 1,133 N and 1,266 N, respectively. Survival rates ranged from 20% to 33.3% (ceramic crowns and onlays) to 60% (composite resin crowns and onlays) and were significantly different (pooled data for restorative material). There were no restoration failures, but there were adhesive failures at the connection between the abutment and the mesostructure. The survival of the metal-composite resin premolar abutments was inferior to that of identical zirconia abutments from a previous study (pooled data for abutment material). Composite resin onlays/crowns bonded to metal-composite resin premolar implant abutments presented higher survival rates than comparable ceramic onlays/crowns. Zirconia abutments outperformed the metal-composite resin premolar abutments.

  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. Bond strength of self-adhesive resin cements to composite submitted to different surface pretreatments.

    Science.gov (United States)

    Dos Santos, Victor Hugo; Griza, Sandro; de Moraes, Rafael Ratto; Faria-E-Silva, André Luis

    2014-02-01

    Extensively destroyed teeth are commonly restored with composite resin before cavity preparation for indirect restorations. The longevity of the restoration can be related to the proper bonding of the resin cement to the composite. This study aimed to evaluate the microshear bond strength of two self-adhesive resin cements to composite resin. COMPOSITE DISCS WERE SUBJECT TO ONE OF SIX DIFFERENT SURFACE PRETREATMENTS: none (control), 35% phosphoric acid etching for 30 seconds (PA), application of silane (silane), PA + silane, PA + adhesive, or PA + silane + adhesive (n = 6). A silicone mold containing a cylindrical orifice (1 mm(2) diameter) was placed over the composite resin. RelyX Unicem (3M ESPE) or BisCem (Bisco Inc.) self-adhesive resin cement was inserted into the orifices and light-cured. Self-adhesive cement cylinders were submitted to shear loading. Data were analyzed by two-way ANOVA and Tukey's test (p composite resin surface might have an effect on the bond strength of self-adhesive resin cements to this substrate.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    Sohrab Asefi

    2016-08-01

    Full Text Available 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 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of 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.

  7. 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 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of 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. PMID:27651887

  8. A randomized controlled 27 years follow up of three resin composites in Class II restorations

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2015-01-01

    Objective: To evaluate the durability of three conventional resin composites in Class II restorations during 27 years. Methods: Thirty participants, 25 female and 5 male (mean age 38.2 years, range 25–63), received at least three (one set) as similar as possible Class II restorations of moderate...... size. The three cavities were chosen at random to be restored with a chemical-cured (Clearfil Posterior) and two visible light-cured resin composites (Adaptic II, Occlusin). A chemical-cured enamel bonding agent (Clearfil New Bond) was applied after Ca(OH)2 covering of dentin and enamel etch. Marginal......: Class II restorations of the three conventional resin composites showed an acceptable success rate during the 27 year evaluation....

  9. Clinical application of Dyract light curing composite resin%Dyract光固化复合体的临床应用

    Institute of Scientific and Technical Information of China (English)

    陈慧华; 胡惠珍; 张龙泉

    2001-01-01

    目的 观察Dyract光固化复合体对牙体病损各类洞型修复的临床疗效。方法 用DyractAP修复277个患牙,随访1年~1.5年,共复查到206个患牙,从修复物形态、密合度、边缘着色、继发龋等几方面来观察疗效。结果 失败率最高为II类洞,达15.38%,依次为IV类洞6.90%,I类洞4.55%,V类洞4.39%,III类洞充填体无脱落。结论 DyractAP粘结性能良好,而在承受咀嚼力上还有欠缺,但其色泽和粘结性能优于GIC。

  10. Improving Composite Resin Performance Through Decreasing its Viscosity by Different Methods

    Science.gov (United States)

    Baroudi, Kusai; Mahmoud, Said

    2015-01-01

    The aim of this work was to present the different current methods of decreasing viscosity of resin composite materials such as (using flowable composites, lowering the viscosity of the monomer mixture, heating composites and applying sonic vibration) and furnish dentists with a basis that can provide criteria for choosing one or another to suit their therapeutic requirements. The four discussed methods proved that lowering composite viscosity improves its handling and facilitates its application to cavities with complicated forms, decreasing time for procedure and improving marginal adaptation. Other properties improved by decreasing composite resin viscosity were controversial between the four methods and affected by other factors such as composite brand and light cure unit. PMID:26312094

  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. 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. PMID:26889359

  13. 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.

  14. Influence of post-cure treatments on hardness and marginal adaptation of composite resin inlay restorations: an in vitro study

    Directory of Open Access Journals (Sweden)

    Laiza Tatiana Poskus

    2009-12-01

    Full Text Available OBJECTIVES: The purpose of this study was to evaluate the Vickers hardness number (VHN and the in vitro marginal adaptation of inlay restorations of three hybrid composite resins (Filtek Z250, Opallis and Esthet-X subjected to two post-cure treatments. MATERIAL AND METHODS: For the microhardness test, three different groups were prepared in accordance with the post-cure treatments: control group (only light cure for 40 s, autoclave group (light cure for 40 s + autoclave for 15 min at 130ºC; and microwave group (light cure for 40 s + microwave for 3 min at 450 W. To assess the marginal adaptation, the composite resin was inserted incrementally into a mesial-occlusal-distal cavity brass mold and each increment light-cured for 40 s. A previous reading in micrometers was taken at the cervical wall, using a stereomicroscope magnifying glass equipped with a digital video camera and image-analysis software. Subsequently, the specimens were subjected to the post-cure treatments (autoclave and microwave and a reading was taken again at the cervical wall. Data were compared using ANOVA for the hardness test, split-plot ANOVA for the adaptation assessment and Tukey's test for multiple comparisons. A significance level of 5% was adopted for all analyses. RESULTS: The post-cure treatments increased the hardness of conventional composites (p<0.001 and the gap values of inlay restorations (p<0.01. Filtek Z250 showed higher hardness (p<0.001 and lower gap values than Opallis and Esthet-X (p<0.05. Gap values did not exceed 90 µm for any of the experimental conditions. CONCLUSION: The post-cure treatments increased the VHN and the gap values on the cervical floor of composite resin inlays. Moreover, Filtek Z250 showed the best results, with higher hardness and lower gap values.

  15. Diametral tensile strength of composite resins submitted to different activation techniques.

    Science.gov (United States)

    Casselli, Denise Sá Maia; Worschech, Claudia Cia; Paulillo, Luis Alexandre Maffei Sartini; Dias, Carlos Tadeu Dos Santos

    2006-01-01

    The aim of this study was to evaluate the diametral tensile strength (DTS) of composite resins submitted to different curing techniques. Four composite resins were tested in this study: Targis (Ivoclar), Solidex (Shofu), Charisma (Heraeus-Kulzer) and Filtek Z250 (3M Espe). Sixty-four cylindrical specimens were prepared and divided into eight groups according to each polymerization technique (n = 8). The indirect composite resins (Targis and Solidex) were polymerized with their respective curing systems (Targis Power and EDG-lux); Charisma and Filtek Z250 were light-cured with conventional polymerization (halogen light) and additionally, with post-curing systems. Specimens were stored in artificial saliva at 37 degrees C for one week. DTS tests were performed in a Universal Testing Machine (0.5 mm/min). The data were statistically analyzed by ANOVA and Duncan tests. The results were (MPa): Z250/EDG-lux: 69.04 feminine; Z250/Targis Power: 68.57 feminine; Z250/conventional polymerization: 60.75b; Charisma/Targis Power: 52.34c; Charisma/conventional polymerization: 49.17c; Charisma/EDG-lux: 47.98c; Solidex: 36.62d; Targis: 32.86d. The results reveal that the post-cured Z250 composite resin showed the highest DTS means. Charisma composite presented no significant differences when activation techniques were compared. Direct composite resins presented higher DTS values than indirect resins.

  16. Optical density and chemical composition of microfilled and microhybrid composite resins

    Directory of Open Access Journals (Sweden)

    Ana Paula Braun

    2008-04-01

    Full Text Available This study evaluated the optical density of two microfilled and two microhybrid resins, as well as the composition of these materials with regard to their optical density. Cavities prepared in 12 2-mm- or 4-mm-thick acrylic plastic plates were filled with Z250 (3M-ESPE, A110 (3M-ESPE, Charisma (Heraeus-Kulzer and DurafillVS (Heraeus-Kulzer. The resin increments (2-mm-thick were light-cured for 40 s. Three 0.12-s radiographic exposures were made of each #2 acrylic plastic plate. DenOptix system optical plates were used to obtain the digital images. Three readings of the composite resin surface were made in each radiograph, totalizing 216 readings. The mean of highest and lowest grey-scale values was obtained. Two specimens of each composite resin were prepared for SEM analysis of the chemical elements related to optical density, using energy dispersive x-ray analysis (EDX. The results were subjected to Shapiro-Wilk's test, ANOVA, Tukey's test at 1% level of significance and Pearson's correlation. The mean grey-scale values at 2 mm and 4 mm were: Z250 = 154.27a and 185.33w; A110 = 46.77b and 63.05y; Charisma = 163.40c and 200.46z; DurafillVS = 43.92b and 58.99x, respectively. Pearson's test did not show any positive correlation between optical density and percentage weight of optical density chemical elements. It was concluded that the microhybrid resins had higher optical density means than the microfilled resins; among the evaluated resins, Charisma had the highest optical density means.

  17. 复合树脂的不同固化方法对抗压强度影响%Effect of composite resins with different curing methods on compressive strength

    Institute of Scientific and Technical Information of China (English)

    徐晓; 崔智骁

    2001-01-01

    目的 探讨不同固化方法处理后对复合树脂抗压强度的影响。方法 采用光固化、光固化+光固化、光固化+热固化,3种不同固化方法处理3M和贺利氏复合树脂,在万能验试机上测试抗压强度。结果 2次处理的复合树脂抗压强度均比1次处理的复合树脂有较大提高,范围在51.8%~91.6%之间。不同的2次固化方法相比,统计学无显著差异。结论 复合树脂经2次固化方法处理,其抗压强度高于1次光固化方法的处理。%Objective To investigate the effect of composite resins dealedwith different curing methods on compressive strength. Methods The compressive strength change were determined by dealing with 3M composite resins and Herues composite resins by light cured, light cured + light cured and light cured + heat cured. Results The compressive strength with secondary cure was significantly higher than that of control groups (light cured only),a range from 51.8%~91.6% (P<0.05) , but there were no statistical difference between two secondary cure groups. Conclusion The compressive strength of secondary cured composite resins is higher than that of light cured only.

  18. Microhybrid and Flowable Microhybrid Dental Resin Composites Measured in Fracture Toughness

    Directory of Open Access Journals (Sweden)

    Decky J. Indrani

    2012-10-01

    Full Text Available Objectives. The aim of this study was to compare the fracture toughness of a microhybrid and a flowable microhyrid resin composites. Methods. Test specimens (30x15x2mm made of a microhybrid and a flowable microhybrid were prepared in a double torsion mould and were then polymerized for 20 seconds using a light-curing device. Taken out from the mould, the specimens were than soaked in disfilled water (37°C for 1 hour and then fractured in a double-torsion technique. t-Test was used to test significance difference between the microhybrid and flowable microhybrid resin composites. Result. The use of double-torsion technique resulted in crack initition and crack arrest which revealed Klc of 1.14 MN/m3/2 and 1.045 MN/m3/2 for the microhybrid and the flowable microhybrid resin composites, respectively. Both resin composites were insignificantly different in the fracture toughness values showed by t–Test. Conclusions. The present study suggested that there was no significant difference between the microhybrid and the flowable microhybrid resin composites tested. It appreared that filler fraction might not affect the fracture toughness of the resin composties tested.DOI: 10.14693/jdi.v16i1.15

  19. Effect of light sources and curing mode techniques on sorption, solubility and biaxial flexural strength of a composite resin

    Directory of Open Access Journals (Sweden)

    Andreia Assis Carvalho

    2012-04-01

    Full Text Available Adequate polymerization plays an important role on the longevity of the composite resin restorations. OBJECTIVES: The aim of this study was to evaluate the effect of light-curing units, curing mode techniques and storage media on sorption, solubility and biaxial flexural strength (BFS of a composite resin. MATERIAL AND METHODS: Two hundred and forty specimens were made of one composite resin (Esthet-X in a stainless steel mold (2 mm x 8 mm Ø, and divided into 24 groups (n=10 established according to the 4 study factors: light-curing units: quartz tungsten halogen (QTH lamp and light-emitting diodes (LED; energy densities: 16 J/cm² and 20 J/cm²; curing modes: conventional (CM and pulse-delay (PD; and permeants: deionized water and 75% ethanol for 28 days. Sorption and solubility tests were performed according to ISO 4049:2000 specifications. All specimens were then tested for BFS according to ASTM F394-78 specification. Data were analyzed by three-way ANOVA followed by Tukey, Kruskal-Wallis and Mann-Whitney tests (α=0.05. RESULTS: In general, no significant differences were found regarding sorption, solubility or BFS means for the light-curing units and curing modes (p>0.05. Only LED unit using 16 J/cm² and PD using 10 s produced higher sorption and solubility values than QTH. Otherwise, using CM (16 J/cm², LED produced lower values of BFS than QTH (p<0.05. 75% ethanol permeant produced higher values of sorption and solubility and lower values of BFS than water (p<0.05. CONCLUSION: Ethanol storage media produced more damage on composite resin than water. In general the LED and QTH curing units using 16 and 20 J/cm² by CM and PD curing modes produced no influence on the sorption, solubility or BFS of the tested resin.

  20. Effect of modulated photo-activation on polymerization shrinkage behavior of dental restorative resin composites.

    Science.gov (United States)

    Tauböck, Tobias T; Feilzer, Albert J; Buchalla, Wolfgang; Kleverlaan, Cornelis J; Krejci, Ivo; Attin, Thomas

    2014-08-01

    This study investigated the influence of modulated photo-activation on axial polymerization shrinkage, shrinkage force, and hardening of light- and dual-curing resin-based composites. Three light-curing resin composites (SDR bulk-fill, Esthet X flow, and Esthet X HD) and one dual-curing material (Rebilda DC) were subjected to different irradiation protocols with identical energy density (27 J cm(-2) ): high-intensity continuous light (HIC), low-intensity continuous light (LIC), soft-start (SS), and pulse-delay curing (PD). Axial shrinkage and shrinkage force of 1.5-mm-thick specimens were recorded in real time for 15 min using custom-made devices. Knoop hardness was determined at the end of the observation period. Statistical analysis revealed no significant differences among the curing protocols for both Knoop hardness and axial shrinkage, irrespective of the composite material. Pulse-delay curing generated the significantly lowest shrinkage forces within the three light-curing materials SDR bulk-fill, Esthet X flow, and Esthet X HD. High-intensity continuous light created the significantly highest shrinkage forces within Esthet X HD and Rebilda DC, and caused significantly higher forces than LIC within Esthet X flow. In conclusion, both the composite material and the applied curing protocol control shrinkage force formation. Pulse-delay curing decreases shrinkage forces compared with high-intensity continuous irradiation without affecting hardening and axial polymerization shrinkage. © 2014 Eur J Oral Sci.

  1. Biomechanical model produced from light-activated dental composite resins: a holographic analysis

    Science.gov (United States)

    Pantelić, Dejan; Vasiljević, Darko; Blažić, Larisa; Savić-Šević, Svetlana; Murić, Branka; Nikolić, Marko

    2013-11-01

    Light-activated dental composites, commonly applied in dentistry, can be used as excellent material for producing biomechanical models. They can be cast in almost any shape in an appropriate silicone mold and quickly solidified by irradiation with light in the blue part of the spectrum. In that way, it is possible to obtain any number of nearly identical casts. The models can be used to study the behavior of arbitrary structure under mechanical loads. To test the technique, a simple mechanical model of the tooth with a mesio-occluso-distal cavity was manufactured. Composite resin restoration was placed inside the cavity and light cured. Real-time holographic interferometry was used to analyze the contraction of the composite resin and its effect on the surrounding material. The results obtained in the holographic experiment were in good agreement with those obtained using the finite element method.

  2. 3M Filtek Z350流动树脂与Pekaseal光固化窝沟封闭剂预防儿童龋病的临床效果研究%Comparison of Preventive Effect of 3M Filtek Z350 Flowable Resin and Pekaseal Light-Cured Sealant for Caries in Children

    Institute of Scientific and Technical Information of China (English)

    蒲寒秋; 肖世芳; 勾京东

    2013-01-01

      目的对比观察3M Filtek Z350流动复合树脂与Pekaseal光固化窝沟封闭剂预防儿童恒磨牙龋病的临床效果。方法对2009年1月至2011年6月间本院门诊符合纳入标准的126名6~10岁儿童的315颗恒磨牙随机分为两组,观察组选择3M Filtek Z350流动复合树脂进行窝沟封闭治疗(病例数=63,牙数=136),对照组采用Pekaseal光固化窝沟封闭剂进行窝沟封闭治疗(病例数=63,牙数=179),随访6个月~1年,复查封闭剂保留情况和患龋情况。结果术后6个月观察组和对照组窝沟封闭剂保留率无统计学差异(P>0.05),术后1年观察组封闭剂保留率高于对照组,差异有统计学意义(P<0.05)。术后6个月、1年,观察组患龋率均低于对照组,差异均有统计学意义(P<0.05)。结论采用3M Filtek Z350流动复合树脂进行窝沟封闭预防儿童恒磨牙窝沟龋效果显著,使龋病发生率大大降低,优于传统的窝沟封闭剂,值得临床推广应用。%Objective To compare the preventive effect of 3M Filtek Z350 flowable resin and Pekaseal light-cured pit and fissure sealant for caries in children. Methods One hundred and twenty six children aged 6 to 10 years were selected to perform sealant technique on their first permanent molars. First molars in trial group were sealed with 3M Filtek Z350 flowable resin and in control group were sealed with Pekaseal light-cured sealant. Sealant retention rate and caries prevalence were observed during 1-year follow up. Rusults At 6-month follow up, there were no statistical difference in sealant retention rate between the two groups(P>0.05). At 1 year follow up, the retention rate of flowable resin group was significantly higher than that of light-cured sealant group(P<0.05). However,caries prevalence of flowable resin group was significantly lower than that of light-cured sealant group at both 6-month and 1-year follow up(P<0.05).Conclusion 3M Filtek Z350 flowable

  3. Failure analysis of resin composite bonded to ceramic.

    Science.gov (United States)

    Della Bona, Alvaro; Anusavice, Kenneth J; Mecholsky, John J

    2003-12-01

    To use fractographic principles to classify the mode of failure of resin composite bonded to ceramic specimens after microtensile testing. A leucite-based ceramic (IPS Empress)-E1) and a lithia disilicate-based ceramic (IPS Empress2)-E2) were selected for the study. Fifteen blocks of E1 and E2 were polished through 1 microm alumina abrasive. The following ceramic surface treatments were applied to three blocks of each ceramic: (1) 9.5% hydrofluoric acid (HF) for 2 min; (2) 4% acidulated phosphate fluoride (APF) for 2 min; (3) Silane coating (S); (4) HF+S; (5) APF+S. An adhesive resin and a resin composite were applied to all treated surfaces and light cured. Twenty bar specimens for each group were prepared from the composite-ceramic blocks and stored in 37 degrees C distilled water for 30 days before loading to failure under tension in an Instron testing machine. Fracture surfaces were examined using scanning electron microscopy and X-ray dot mapping. Statistical analysis was performed using one-way ANOVA, Duncan's multiple range test, and Weibull analyses. Similar surface treatments were associated with significantly different bond strengths and modes of failures for E1 and E2. All fractures occurred within the adhesion zone. The microstructural difference between etched E1 and E2 ceramics was a major controlling factor on adhesion. The quality of the bond should not be assessed based on bond strength data alone. Mode of failure and fractographic analyses should provide important information leading to predictions of clinical performance limits.

  4. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments

    OpenAIRE

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    Objective: The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. Materials and Methods: A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the res...

  5. Shear bond strength between titanium alloys and composite resin: sandblasting versus fluoride-gel treatment.

    Science.gov (United States)

    Lim, Bum-Soon; Heo, Seok-Mo; Lee, Yong-Keun; Kim, Cheol-We

    2003-01-15

    The aim of this study was to investigate the effect of fluoride gel treatment on the bond strength between titanium alloys and composite resin, and the effect of NaF solution on the bond strength of titanium alloys. Five titanium alloys and one Co-Cr-Mo alloy were tested. Surface of the alloys were treated with three different methods; SiC polishing paper (No. 2000), sandblasting (50-microm Al2O3), and commercially available acidulated phosphate fluoride gel (F-=1.23%, pH 3.0). After treatment, surfaces of alloy were analyzed by SEM/EDXA. A cylindrical gelatin capsule was filled with a light-curable composite resin. The composite resin capsule was placed on the alloy surface after the application of bonding agent, and the composite resin was light cured for 30 s in four different directions. Shear bond strength was measured with the use of an Instron. Fluoride gel did not affect the surface properties of Co-Cr-Mo alloy and Ni-Ti alloy, but other titanium alloys were strongly affected. Alloys treated with the fluoride gel showed similar bond strengths to the alloys treated with sandblasting. Shear bond strength did not show a significant difference (ptitanium alloys. To enhance the bond strength of composite resin to titanium alloys, fluoride-gel treatment may be used as an alternative technique to the sandblasting treatment.

  6. Odontological light-emitting diode light-curing unit beam quality.

    Science.gov (United States)

    de Magalhães Filho, Thales Ribeiro; Weig, Karin de Mello; Werneck, Marcelo Martins; da Costa Neto, Célio Albano; da Costa, Marysilvia Ferreira

    2015-05-01

    The distribution of light intensity of three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] was calculated. The index is based on the M2 index, which is used for laser beams. An optical spectrum analyzer was used with an optical fiber to produce an x-y power profile of each LCU light guide. The FTF-calculated values were 0.51 for LCU1 and 0.55 for LCU2, which was the best FTF, although it still differed greatly from the perfect FTF = 1, and 0.27 for LCU3, which was the poorest value and even lower than the Gaussian FTF = 0.5. All LCUs presented notably heterogeneous light distribution, which can lead professionals and researchers to produce samples with irregular polymerization and poor mechanical properties.

  7. Polymerization shrinkage and contraction force of composite resin restorative inserted with "Megafiller".

    Science.gov (United States)

    Tani, Y; Nambu, T; Ishikawa, A; Katsuyama, S

    1993-12-01

    This study quantified the contraction force and polymerization shrinkage of composite resins with/without beta-Quartz Glass Ceramic Inserts (BQCI) as "Megafiller". The materials used for the determination included a chemically cured composite and five light-cured composites. The system for measuring contraction force consisted of a transparent teflon tube for preparing the specimen, a small load cell, a dynamic strain gauge and a pen-recorder. After the composite was packed into the teflon mold, a BQCI (Type R3) was inserted through the opening and the specimen was cured. Linear polymerization shrinkage of the composites was measured every 10 seconds from the start of mixing or irradiation to 90 minutes by the mercury bath method. Three pieces each of BQCI (Type T3) were inserted in each specimen. The results suggested that BQCI was markedly effective in reducing polymerization shrinkage, but was not always effective in reducing the contraction force during polymerization.

  8. Release and toxicity of dental resin composite

    OpenAIRE

    Saurabh K Gupta; Saxena, Payal; Pant, Vandana A.; Pant, Aditya B.

    2012-01-01

    Dental resin composite that are tooth-colored materials have been considered as possible substitutes to mercury-containing silver amalgam filling. Despite the fact that dental resin composites have improved their physico-chemical properties, the concern for its intrinsic toxicity remains high. Some components of restorative composite resins are released in the oral environment initially during polymerization reaction and later due to degradation of the material. In vitro and in vivo studies h...

  9. Effect of a multi-layer infection control barrier on the micro-hardness of a composite resin

    OpenAIRE

    In-Nam Hwang; Sung-Ok Hong; Bin-Na Lee; Yun-Chan Hwang; Won-Mann Oh; Hoon-Sang Chang

    2012-01-01

    OBJECTIVE: The aim of this study was to evaluate the effect of multiple layers of an infection control barrier on the micro-hardness of a composite resin. MATERIAL AND METHODS: One, two, four, and eight layers of an infection control barrier were used to cover the light guides of a high-power light emitting diode (LeD) light curing unit (LCU) and a low-power halogen LCU. The composite specimens were photopolymerized with the LCUs and the barriers, and the micro-hardness of the upper and lower...

  10. Resin composites in minimally invasive dentistry.

    Science.gov (United States)

    Jacobsen, Thomas

    2004-01-01

    The concept of minimally invasive dentistry will provide favorable conditions for the use of composite resin. However, a number of factors must be considered when placing composite resins in conservatively prepared cavities, including: aspects on the adaptation of the composite resin to the cavity walls; the use of adhesives; and techniques for obtaining adequate proximal contacts. The clinician must also adopt an equally conservative approach when treating failed restorations. The quality of the composite resin restoration will not only be affected by the outline form of the preparation but also by the clinician's technique and understanding of the materials.

  11. Advanced resin systems for graphite epoxy composites

    Science.gov (United States)

    Gilwee, W. J.; Jayarajan, A.

    1980-01-01

    The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.

  12. Color stability of different composite resin materials.

    Science.gov (United States)

    Falkensammer, Frank; Arnetzl, Gerwin Vincent; Wildburger, Angelika; Freudenthaler, Josef

    2013-06-01

    Data are needed to better predict the color stability of current composite resin materials. The purpose of this study was to evaluate the impact of different storage solutions on the color stability of different composite resin materials. Different restorative and adhesive composite resin specimens (dual-polymerizing self-adhesive resin cement, autopolymerizing resin-based composite resin, dual-polymerizing resin-based composite resin, nanohybrid composite resin, and microhybrid composite resin) were fabricated and stored in red wine, black tea, chlorhexidine, sodium fluoride, tea tree oil, or distilled water for 4 weeks at 37°C. Color parameters were measured with a colorimeter before and after storage. Total color differences and specific coordinate differences were expressed as ΔE, ΔL, Δa, and Δb. A 2-way and 1-way analysis of variance (ANOVA) with Bonferroni adjustment for multiple comparisons were applied for statistical calculations (α=.05). Red wine caused the most severe discoloration (ΔE >10), followed by black tea with perceptible (ΔE >2.6) to clinically unacceptable discoloration (ΔE >5.5). Colored mouth rinses discolored the materials to a lesser extent with clinically acceptable values. Dual-polymerizing resin adhesives showed a higher amount of discoloration. Current restorative and adhesive composite resin materials discolor over time under the influence of different storage solutions. The composition related to the polymerizing mode seemed to be a causative factor. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  13. Shear Bond Strength of Resin Buttons to Lithium Disilicate and Leucite Reinforced Feldspathic Restorations

    Science.gov (United States)

    2016-05-01

    restorative materials and found that self- adhesive resins could provide clinically acceptable bond strengths to enamel, restorative resin composite and...Comparative tensile strengths of brackets bonded to porcelain with orthodontic adhesive and porcelain repair systems . Am J Orthod Dentofac Orthop (94): 421...sample of each group was photographed with scanning electron microscopy (SEM). 1) Group A: silane coupling agent, light cured composite , and

  14. 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.

  15. Measurement of solubility and water sorption of dental nanocomposites light cured by argon laser.

    Science.gov (United States)

    Mirsasaani, Seyed Shahabeddin; Ghomi, Farhad; Hemati, Mehran; Tavasoli, Tina

    2013-03-01

    Different parameters used for photoactivation process and also composition provide changes in the properties of dental composites. In the present work the effect of different power density of argon laser and filler loading on solubility (SL) and water sorption (WS) of light-cure dental nanocomposites was studied. The resin of nanocomposites was prepared by mixing bisphenol A glycol dimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) with a mass ratio of 65/35. 20 wt.% and 25 wt.% of nanosilica fillers with a primary particle size of 10 nm were added to the resin. Camphorquinone (CQ) and DMAEMA were added as photoinitiator system. The nanocomposites were cured by applying the laser beam at the wavelength of 472 nm and power densities of 260 and 340 mW/cm(2) for 40 sec. Solubility and water sorption were then measured according to ISO 4049, which in our case, the maximums were 2.2% and 4.3% at 260 mW/cm(2) and 20% filler, respectively. The minimum solubility (1.2%) and water sorption (3.8%) were achieved for the composite containing 25% filler cured at 340 mW/cm(2). The results confirmed that higher power density and filler loading decreased solubility of unreacted monomers and water sorption and improved physico-mechanical properties of nanocomposites.

  16. 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.

  17. [An in vitro study of wear and marginal fracture of posterior composite resins].

    Science.gov (United States)

    Futatsuki, M; Nakata, M

    1990-01-01

    The collision-and-abrasion test was performed to reproduce the change of the surface structures of posterior composite resins by the stress of mastication and occlusion. Also the effect of the stress on wear and marginal fracture of composites was estimated qualitatively and quantitatively between the cavities with round bevel, straight bevel and butt joint. Extracted human posterior teeth were used as materials, and round or straight bevels were prepared along the margin of the standardized cavities using the bevel-preparing burs which had been designed by us. Light cured posterior composite resin (Occlusin/ICI Co.) was used as the restoration material. Also the surface structures were examined before and after the collision-and-abrasion test with the scanning electron microscope and laser measuring device for the surface morphology. The following results were obtained. 1. The collision-and-abrasion test with use of the slurry of polymethyl methacrylate (PMMA) powder as abrasive showed better reproducing ability of the in vivo change of the posterior composite restorations. 2. The collision stress was found to be one of the main causes for the wear and marginal fracture of composites. 3. It was found that the measurement for wear and marginal fracture of restorations could be performed three-dimensionally with high precision and in shorter time by using a laser device. 4. Marginal fracture resistance of composite resins is influenced by the adhesion with tooth structure and the marginal thickness. Therefore, the best marginal shape for posterior composite restoration is the round bevel.

  18. Release and toxicity of dental resin composite.

    Science.gov (United States)

    Gupta, Saurabh K; Saxena, Payal; Pant, Vandana A; Pant, Aditya B

    2012-09-01

    Dental resin composite that are tooth-colored materials have been considered as possible substitutes to mercury-containing silver amalgam filling. Despite the fact that dental resin composites have improved their physico-chemical properties, the concern for its intrinsic toxicity remains high. Some components of restorative composite resins are released in the oral environment initially during polymerization reaction and later due to degradation of the material. In vitro and in vivo studies have clearly identified that these components of restorative composite resins are toxic. But there is a large gap between the results published by research laboratories and clinical reports. The objective of this manuscript was to review the literature on release phenomenon as well as in vitro and in vivo toxicity of dental resin composite. Interpretation made from the recent data was also outlined.

  19. Posterior adhesive composite resin: a historic review.

    Science.gov (United States)

    Fusayama, T

    1990-11-01

    Since development of the BIS-GMA composite resin, there have been many innovations to improve the physical properties for posterior use. Subsequent development of a caries detector and chemically adhesive composite resin has further revolutionally raised the value of composite resin restoration, replacing the traditional restorative system of mechanical approach by the new system of biological approach. In this system only the infected irreversibly deteriorated insensitive tissue, stainable with the caries detector, is removed painlessly. The cavity is immediately filled with the composite resin with no further tissue reduction for retention or resistance form or extension for prevention. Both enamel and dentin walls are etched by a single etchant without lining. The chemical adhesion to the cavity margin and wall minimizes the marginal failure in size and prevalence and prevents secondary caries penetration along the wall. The chemically adhesive composite resin is thus a useful restorative material much kinder to teeth than amalgam.

  20. Luminous Efficient Compositions Based on Epoxy Resin

    Directory of Open Access Journals (Sweden)

    R.S. Palaiah

    2006-07-01

    Full Text Available Magnesium/sodium nitrate illuminating compositions with epoxy resin - E 605 have beenstudied for luminosity and luminous efficiency by varying fuel oxidizer ratio and binder content.The compositions have been evaluated for impact and friction sensitivities, burn rate, thermalcharacteristics, and mechanical properties. Flame temperature and combustion products areevaluated theoretically by using REAL program. Experimental results show that, luminosity,burn rate, and calorimetric value are higher for polyester resin-based compositions. The highluminous efficiency composition is achieved with magnesium/sodium nitrate ratio of 70/30 with4 per cent epoxy resin.

  1. Cytotoxicity of resin composites containing bioactive glass fillers.

    Science.gov (United States)

    Salehi, Satin; Gwinner, Fernanda; Mitchell, John C; Pfeifer, Carmem; Ferracane, Jack L

    2015-02-01

    To determine the in vitro cytotoxicity of dental composites containing bioactive glass fillers. Dental composites (50:50 Bis-GMA/TEGDMA resin: 72.5wt% filler, 67.5%Sr-glass and 5% OX50) containing different concentrations (0, 5, 10 and 15wt%) of two sol-gel bioactive glasses, BAG65 (65mole% SiO2, 31mole% CaO, 4mole% P2O5) and BAG61 (3mole% F added) were evaluated for cytotoxicity using Alamar Blue assay. First, composite extracts were obtained from 7 day incubations of composites in cell culture medium at 37°C. Undifferentiated pulp cells (OD-21) were exposed to dilutions of the original extracts for 3, 5, and 7 days. Then freshly cured composite disks were incubated with OD-21 cells (n=5) for 2 days. Subsequently, fresh composite disks were incubated in culture medium at 37°C for 7 days, and then the extracted disks were incubated with OD-21 cells for 2 days. Finally, fresh composites disks were light cured for 3, 5, and 20s and incubated with OD-21 cells (n=5) for 1, 3, 5, and 7 days. To verify that the three different curing modes produced different levels of degree of conversion (DC), the DC of each composite was determined by FTIR. Groups (n=5) were compared with ANOVA/Tukey's (α≤0.05). Extracts from all composites significantly reduced cell viability until a dilution of 1:8 or lower, where the extract became equal to the control. All freshly-cured composites showed significantly reduced cell viability at two days. However, no reduction in cell viability was observed for any composite that had been previously soaked in media before exposure to the cells. Composites with reduced DC (3s vs. 20s cure), as verified by FTIR, showed significantly reduced cell viability. The results show that the composites, independent of composition, had equivalent potency in terms of reducing the viability of the cells in culture. Soaking the composites for 7 days before exposing them to the cells suggested that the "toxic" components had been extracted and the materials were

  2. The influence of "C-factor" and light activation technique on polymerization contraction forces of resin composite

    Directory of Open Access Journals (Sweden)

    Sérgio Kiyoshi Ishikiriama

    2012-12-01

    Full Text Available OBJECTIVES: This study evaluated the influence of the cavity configuration factor ("C-Factor" and light activation technique on polymerization contraction forces of a Bis-GMA-based composite resin (Charisma, Heraeus Kulzer. MATERIAL AND METHODS: Three different pairs of steel moving bases were connected to a universal testing machine (emic DL 500: groups A and B - 2x2 mm (CF=0.33, groups C and D - 3x2 mm (CF=0.66, groups e and F - 6x2 mm (CF=1.5. After adjustment of the height between the pair of bases so that the resin had a volume of 12 mm³ in all groups, the material was inserted and polymerized by two different methods: pulse delay (100 mW/cm² for 5 s, 40 s interval, 600 mW/cm² for 20 s and continuous pulse (600 mW/cm² for 20 s. Each configuration was light cured with both techniques. Tensions generated during polymerization were recorded by 120 s. The values were expressed in curves (Force(N x Time(s and averages compared by statistical analysis (ANOVA and Tukey's test, p<0.05. RESULTS: For the 2x2 and 3x2 bases, with a reduced C-Factor, significant differences were found between the light curing methods. For 6x2 base, with high C-Factor, the light curing method did not influence the contraction forces of the composite resin. CONCLUSIONS: Pulse delay technique can determine less stress on tooth/restoration interface of adhesive restorations only when a reduced C-Factor is present.

  3. 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.

  4. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments.

    Science.gov (United States)

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the restorations were removed out leaving only middle part. One side of the cavity was finished with course diamond bur and the other was air-abraded with 50 μm Al2O3. They were randomly divided into four groups (n = 10) to receive: Group 1: Adper Single Bond 2; Group 2: All Bond 3; Group 3: ClearfilSE; Group 4: BeautiBond, before being repaired with the same resin composite (Filtek Z250). The specimens were re-thermocycled (1000×), sealed with nail varnish, stained with 0.5% basic fuchsin, sectioned mesiodistally and photographed digitally. The extent of dye penetration was measured by image analysis software (ImageJ) for both bur-finished and air-abraded surfaces at resin-tooth and resin-resin interfaces. The data were analyzed statistically. BeautiBond exhibited the most microleakage at every site. Irrespective of adhesive and initial composite type, air-abrasion showed less microleakage except for BeautiBond. The type of initial repaired restorative material did not affect the microleakage. BeautiBond adhesive may not be preferred in resin composite repair in terms of microleakage prevention. Surface treatment with air-abrasion produced the lowest microleakage scores, independent of the adhesive systems and the pre-existing resin composite type. Pre-existing composite type does not affect the microleakage issue. All-in-one adhesive resin (BeautiBond) may not be preferred in resin composite repair in terms of microleakage prevention.

  5. Color changes of dental resin composites before and after polymerization and storage in water.

    Science.gov (United States)

    Çelık, Esra Uzer; Aladağ, Akin; Türkün, L Şebnem; Yilmaz, Gökhan

    2011-06-01

    The aims of this study were to: (1) evaluate the A2 shades of various types and brands of resin composites to determine if any color differences occurred before and after polymerization and after 1 month of storage in water and (2) examine the correlation among the color changes and changes in Commission internationale de l'éclairage L*, a*, and b* values after polymerization and after 1 month of storage in water. One submicron-hybrid (Spectrum TPH3, DENTSPLY DeTrey, Milford, DE, USA), one nano-filled (Filtek Supreme XT, 3 M ESPE, St. Paul, MN, USA), three micro-hybrid (Filtek Z250, 3 M ESPE; Esthet X, DENTSPLY DeTrey; and Gradia Direct, GC, Tokyo, Japan), and five nano-hybrid (Ceram X, DENTSPLY DeTrey; Clearfil Majesty Esthetics, Kuraray, Osaka, Japan; Premise, Kerr Corporation, Orange, CA, USA; Tetric Evo Ceram, Ivoclar Vivadent, Schaan, Liechtenstein and Tetric N Ceram, Ivoclar Vivadent) light-curing resin composites were tested. The specimens (N = 10 for each composite) were prepared as discs, 12 mm in diameter and 2 mm in thickness, using round molds. The measurements were performed "before polymerization,"after polymerization," and "after 1 month of storage in water" using a contact type dental spectrophotometer (Vita Easyshade, Vident, Brea, CA, USA). The range of ΔE* values after polymerization (ΔE*1) and storage in water (ΔE*2) were 4.59 to 14.13 and 1.26 to 6.29, respectively. Nested analysis of variance and post hoc tests revealed that the type of resin composites significantly affected Δa*1, Δa*2, Δb*1, Δb*2, ΔE*2-values, whereas the brand of resin composites affected the changes in all color parameters (p compositions and fillers of the contemporary composites, color changes after polymerization were perceptible in all resin composites. However, color changes after storage in water were in the acceptable ranges for all resin composites except Clearfil Majesty Esthetic and Gradia Direct. In spite of many improvements in chemical compositions

  6. Clinical applications of preheated hybrid resin composite.

    Science.gov (United States)

    Rickman, L J; Padipatvuthikul, P; Chee, B

    2011-07-22

    This clinical article describes and discusses the use of preheated nanohybrid resin composite for the placement of direct restorations and luting of porcelain laminate veneers. Two clinical cases are presented. Preheating hybrid composite decreases its viscosity and film thickness offering the clinician improved handling. Preheating also facilitates the use of nanohybrid composite as a veneer luting material with relatively low polymerisation shrinkage and coefficient of thermal expansion compared to currently available resin luting cements.

  7. Histo-pathological study of pulp response to a composite resin restoration with two lining materials.

    Science.gov (United States)

    Aoki, S; Ishikawa, T

    1990-11-01

    This histopathological study investigated the pulp reaction to a restoration system employing a posterior composite resin with or without the pulp protection of visible light curing calcium hydroxide composition and alpha-TCP cement lining to dentin. Black's class V cavities were prepared in 120 adult dog teeth. They were then extracted for histological examination. As a result of this study, their lining materials were found to be effective in pulp protection. To understand the pathological finding, the pH values of "Fulfil", "Universal bond", "VLC Dycal" and "Vitacemen Type II" were measured. The pH levels of "Fulfil" and "Universal Bond" were mildly acidic (4.79-5.18) before polymerization, with no subsequent changes. "VLC Dycal" was initially a strongly alkaline (11.75) and remained this condition. "Vitacemen Type II" was initially acidic (3.78), but eventually reached the milder acidity of 5.12 after 24 hours.

  8. Streptococcus mutans-induced secondary caries adjacent to glass ionomer cement, composite resin and amalgam restorations in vitro.

    Science.gov (United States)

    Gama-Teixeira, Adriana; Simionato, Maria Regina Lorenzeti; Elian, Silvia Nagib; Sobral, Maria Angela Pita; Luz, Maria Aparecida Alves de Cerqueira

    2007-01-01

    The aim of this study was to define, in vitro, the potential to inhibit secondary caries of restorative materials currently used in dental practice. Standard cavities were prepared on the buccal and lingual surfaces of fifty extracted human third molars. The teeth were randomly divided into five groups, each one restored with one of the following materials: glass ionomer cement (GIC); amalgam; light-cured composite resin; ion-releasing composite; and light-cured, fluoride-containing composite resin. The teeth were thermocycled, sterilized with gamma irradiation, exposed to a cariogenic challenge using a bacterial system using Streptococcus mutans, and then prepared for microscopic observation. The following parameters were measured in each lesion formed: extension, depth, and caries inhibition area. The outer lesions developed showed an intact surface layer and had a rectangular shape. Wall lesions were not observed inside the cavities. After Analysis of Variance and Component of Variance Models Analysis, it was observed that the GIC group had the smallest lesions and the greatest number of caries inhibition areas. The lesions developed around Amalgam and Ariston pHc restorations had an intermediate size and the largest lesions were observed around Z-100 and Heliomolar restorations. It may be concluded that the restorative materials GIC, amalgam and ion-releasing composites may reduce secondary caries formation.

  9. Comparative evaluation of surface hardness and depth of cure of silorane and methacrylate-based posterior composite resins: An in vitro study

    Directory of Open Access Journals (Sweden)

    Abhishek Agrawal

    2015-01-01

    Full Text Available Aim: This in vitro study was carried out to compare the effect of LED light curing system on polymerization and hardness of silorane-based and methacrylate-based posterior composite resin. Materials and Methods: A total of 40 samples, 20 of silorane-based composite Filtek P-90 and 20 of methacrylate-based composite Heliomolar HB measuring 2 mm thickness and 8 mm diameter were prepared using Teflon molds and cured using LED curing light. The samples were polished and tested in Knoop hardness tester using a 50-gram load and dwell time of 15 seconds on top and bottom surfaces. The percentage depth of cure was calculated, and statistical analysis was performed using two-way ANOVA test and Student t- test. Results: Higher statistically significant values were seen for both the top and bottom surface hardness in silorane-based resins than methacrylate-based resins on LED light curing. Conclusion: Greater depth of cure was achieved in silorane-based posterior composite than in methacrylate-based posterior composite resins with a statistically significant difference.

  10. 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

  11. Comparison of Surface Hardness of Various Shades of Twinky Star Colored Compomer Light-cured with QTH and LED Units

    Science.gov (United States)

    Khodadadi, Effat; Khafri, Soraya; Aziznezhad, Mahdiyeh

    2016-01-01

    Introduction Colored compomers are a group of restorative materials that were introduced in 2002 to repair primary teeth, and they provide attractive color and ease of use in pediatric dentistry. The aim of this study was to evaluate the effect of QTH and LED light-curing units on the surface hardness of different colors of Twinky Star compomers. Methods In this experimental study, a composite resin (Z250, 3M, and USA), an ionosit compomer (DMG, Germany) with A3 shade and 8 different Twinky Star colored compomer (Voco, Germany) samples were used. In all, 100 samples were prepared with 10 samples in each group, i.e., 10 Z250 composite resin, 10 ionosit compomers, and 10 Twinky Star compomer samples of each color. The samples were prepared in a 4×4-mm Teflon mold. Half of the samples were light-cured with QTH and the other half with LED units. Then, the surface microhardness was measured by Vickers hardness test. The data were analyzed with IBM-SPSS version 22, using the t-test and ANOVA. Results Two-way ANOVA showed that the mean surface hardness of the compomer samples cured with the QTH unit was significantly higher than that cured with the LED unit (p < 0.001). In each curing unit, surface hardness of some materials exhibited significant differences with the highest hardness being observed in the Z250 composite resin (650.35 ± 56.320) and the lowest hardness being detected in the ionosit compomers (461.10 ± 96.170). One-way ANOVA also showed that, among the different colors of the Twinky Star compomer, the lowest hardness with both units (QTH and LED) was observed in the gold color (214.32 ± 22.026 and 175.116 ± 15.918, respectively). Conclusion The colored compomer and the type of light-curing unit affected the microhardnesses of the surfaces. Different colors of Twinky Star compomers exhibited different surface microhardnesses. PMID:27382444

  12. Indirect composite resin materials for posterior applications.

    Science.gov (United States)

    Shellard, E; Duke, E S

    1999-12-01

    Indirect composite resin restorations were introduced a number of years ago as possible alternatives to traditional metallic or ceramic-based indirect restorations. However, the earlier formulations did not provide evidence of improvement in mechanical and physical properties over chairside-placed direct composite resin materials. Because they required more tooth structure removal than direct restorations, their use became unpopular and was abandoned by most clinicians. Over the past few years, a new class of composite resin indirect materials has surfaced in the profession. Various technologies have been suggested as reinforcement mechanisms. Fibers, matrix modifications, and an assortment of innovations have been proposed for enhancing indirect composite resin restorations. Applications are from inlay restorations all the way to multi-unit fixed prostheses. This manuscript summarizes some of the progress made in this area. When available, data is presented to provide clinicians with guidelines and indications for the use of these materials.

  13. Application of glass ionomer and light-cured resin sealant to the pit and fissure of deciduous teeth%玻璃离子与光固化树脂封闭剂封闭乳牙窝沟

    Institute of Scientific and Technical Information of China (English)

    任飞; 刘建平; 黄少宏; 李艳容; 范卫华; 陈晓春; 陈清

    2011-01-01

    背景:传统方法玻璃离子作为封闭剂耐磨性能差,抗折强度低,位于合面的封闭剂很容易脱落,很难取代树脂封闭剂.目的:观察光固化树脂封闭剂和非创伤性充填技术玻璃离子窝沟封闭幼儿乳牙的效果.方法:按同人半口随机比较的方法,对89名3岁幼儿的左或右半口符合窝沟封闭条件的乳磨牙在非创伤性充填技术下行玻璃离子窝沟封闭,对侧半口符合窝沟封闭条件的乳磨牙进行树脂封闭.结果与结论:窝沟封闭后6,18个月玻璃离子组封闭物脱落率均低于树脂材料组(P < 0.05).玻璃离子材料最易脱落的牙位是下颌第二乳磨牙;树脂材料最易脱落的牙位是上颌第二乳磨牙.封闭后6个月,玻璃离子组封闭的乳牙患龋率低于树脂材料组,18个月时两组间差异无显著性意义.说明非创伤性充填技术玻璃离子窝沟封闭幼儿乳牙的脱落率低,操作简单,防龋效果肯定,且成本低,在经济学上可行性优于树脂封闭.%BACKGROUND: Traditional glass ion sealant has a poor abradability and a low rupture strength. The sealant on the occlusal surfaces easily fell off, and is difficult to replace resin sealant. OBJECTIVE: To observe the effects of traditional resin sealant and atraumatic restorative treatment (ART) glass ionomer-based pit and fissure sealant for the young children. METHODS: Randomized comparison method was used to compare ART glass ionomer-based pit on molars of one side with resin sealant on the opposite side in 89 3-year-old children. RESULTS AND CONCLUSION: The retention rates of ART glass ionomer sealant after 6 and 18 months were significantly lower than those of resin sealant (P < 0.05). The caducous position of ART gliass ionomer sealant was the second deciduous molar of the lower mandible, but the caducous position of resin sealant was the second deciduous molar of the upper mandible. The secondary caries rate of ART glass ionomer sealant was significantly

  14. Composite resin in medicine and dentistry.

    Science.gov (United States)

    Stein, Pamela S; Sullivan, Jennifer; Haubenreich, James E; Osborne, Paul B

    2005-01-01

    Composite resin has been used for nearly 50 years as a restorative material in dentistry. Use of this material has recently increased as a result of consumer demands for esthetic restorations, coupled with the public's concern with mercury-containing dental amalgam. Composite is now used in over 95% of all anterior teeth direct restorations and in 50% of all posterior teeth direct restorations. Carbon fiber reinforced composites have been developed for use as dental implants. In medicine, fiber-reinforced composites have been used in orthopedics as implants, osseous screws, and bearing surfaces. In addition, hydroxyapatite composite resin has become a promising alternative to acrylic cement in stabilizing fractures and cancellous screw fixation in elderly and osteoporotic patients. The use of composite resin in dentistry and medicine will be the focus of this review, with particular attention paid to its physical properties, chemical composition, clinical applications, and biocompatibility.

  15. Resin composites : Sandwich restorations and curing techniques

    OpenAIRE

    Lindberg, Anders

    2005-01-01

    Since the mid-1990s resin composite has been used for Class II restorations in stress-bearing areas as an alternative to amalgam. Reasons for this were the patients’ fear of mercury in dental amalgam and a growing demand for aesthetic restorations. During the last decades, the use of new resin composites with more optimized filler loading have resulted in reduced clinical wear. Improved and simplified amphiphilic bonding systems have been introduced. However, one of the main problems with res...

  16. A restorative approach for class II resin composite restorations: a two-year follow-up.

    Science.gov (United States)

    Santos, M J M C

    2015-01-01

    This clinical report describes a restorative technique used to replace two Class II resin composite restorations on the upper premolars. A sectional matrix band was used in conjunction with an elastic ring (Composi-Tight) to obtain tight proximal contact. A nanofilled resin composite (Filtek Supreme Ultra) was incrementally applied using oblique layers to reduce the C-factor, each layer being no more than 2 mm thick, and then light cured for 20 seconds with a light-emitting diode lamp (EliparFreeLight 2 LED Curing Light) with a power density of 660 mW/cm(2). A centripetal technique was used to restore the lost tooth structure from the periphery toward the center of the cavity in order to achieve a better contour and anatomy with less excess, thereby minimizing the use of rotary instruments during the finishing procedures. Finally, the resin composite restorations were finished and polished, and a surface sealer (Perma Seal) was applied to fill small gaps and defects that may have been present on the surfaces and margins of the restorations after the finishing and polishing procedures.

  17. 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.

  18. Influence of light curing units on failure of directcomposite restorations

    Directory of Open Access Journals (Sweden)

    Sameer Jadhav

    2011-01-01

    Full Text Available Light polymerizable tooth colored restorative materials are most widely preferred for advantages such as esthetics, improved physical properties and operator′s control over the working time. Since the introduction of these light polymerizable restorative materials, there has been a concern about the depth of appropriate cure throughout the restoration. Photopolymerization of the composite is of fundamental importance because adequate polymerization is a crucial factor for optimization of the physical and mechanical properties and clinical results of the composite material. Inadequate polymerization results in greater deterioration at the margins of the restoration, decreased bond strength between the tooth and the restoration, greater cytotoxicity, and reduced hardness. Therefore, the dentist must use a light curing unit that delivers adequate and sufficient energy to optimize composite polymerization. Varying light intensity affects the degree of conversion of monomer to polymer and depth of cure.

  19. 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

  20. 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.

  1. Effect of temporary filling materials on repair bond strengths of composite resins.

    Science.gov (United States)

    Erdemir, Ali; Eldeniz, Ayce Unverdi; Belli, Sema

    2008-08-01

    Endodontic access cavities sometimes can be prepared through a permanent composite restoration. Between the appointments, temporary cements are used to seal access cavities and may have negative effect on bonding of further composite restoration. The purpose of this study was to compare shear bond strength of composite to composite which had been in contact with various temporary filling materials. Standard cavities were prepared on 160 acrylic resin blocks, obturated with composite resin (Clearfil AP-X, Kuraray, Japan) and randomly divided into eight groups (n = 20). Group 1 received no treatment. From group 2-8, composite surfaces were covered with the following cements temporarily: Zinc-oxide/calcium-sulphate (Cavit-G, ESPE, Germany), two different Zinc-Oxide-Eugenol materials (ZnOE, Cavex, Holland and IRM, Dentsply, USA), Zinc-phosphate cement (Adhesor, Spofa-Dental, Germany), Zinc-polycarboxylate cement (Adhesor-Carbofine, Spofa-Dental, Germany), Glass-Ionomer-Cement (Argion-Molar, Voco, Germany), or light curing temporary material (Clip, Voco, Germany). The cements were removed mechanically after 1 week storage in distilled water at 37 degrees C and composite surfaces were treated with a self-etch adhesive system (SE-Bond, Kuraray, Japan). Composite resin build-ups were created on composite surfaces. Shear bond strength values were measured using universal testing machine at crosshead speed of 1 mm/min. The data was calculated in MPa and statistically analyzed using one-way ANOVA and Tukey tests. Eugenol-containing cements significantly reduced shear bond strengths of composite to composite (p materials had no adverse effect on shear bond strength (p > 0.05). These findings suggested that temporary filling materials except eugenol-containing materials have no negative effect on composite repair bond strengths.

  2. Effects of different solutions on the surface hardness of composite resin materials.

    Science.gov (United States)

    Yanikoğlu, Nuran; Duymuş, Zeynep Yeşil; Yilmaz, Baykal

    2009-05-01

    In this study, the surface hardness of five light-cured composite resins were evaluated, namely: filled (Estelite), nanofil (AElite), unfilled (Valux Plus), hybrid (Tetric ceram), and Ormocer-based (Admira) composite resins. The microhardness values of composite specimens were measured at the top and bottom surfaces after 24 hours or 30 days of immersion in different solutions (tea, coffee, Turkish coffee, mouthwash, cola, and distilled water). Comparisons were made with univariate analysis of variance and Duncan's multiple range test. It was found that rough specimens of reinforced nano-hybrid composite material immersed in cola for 30 days had the lowest surface hardness (33.20), whereas rough specimens of hybrid composite material immersed in cola for 24 hours had the highest surface hardness (156.00). In both tea and coffee, the top surfaces tended to be harder than the bottom ones. In conclusion, the five different materials exhibited different hardnesses, and that the hardness values of composite materials were statistically different in different immersion solutions.

  3. Effect of surface treatments of laboratory-fabricated composites on the microtensile bond strength to a luting resin cement.

    Science.gov (United States)

    Soares, Carlos José; Giannini, Marcelo; Oliveira, Marcelo Tavares de; Paulillo, Luis Alexandre Maffei Sartini; Martins, Luis Roberto Marcondes

    2004-03-01

    The purpose of this study was to evaluate the influence of different surface treatments on composite resin on the microtensile bond strength to a luting resin cement. Two laboratory composites for indirect restorations, Solidex and Targis, and a conventional composite, Filtek Z250, were tested. Forty-eight composite resin blocks (5.0 x 5.0 x 5.0mm) were incrementally manufactured, which were randomly divided into six groups, according to the surface treatments: 1- control, 600-grit SiC paper (C); 2- silane priming (SI); 3- sandblasting with 50 mm Al2O3 for 10s (SA); 4- etching with 10% hydrofluoric acid for 60 s (HF); 5- HF + SI; 6 - SA + SI. Composite blocks submitted to similar surface treatments were bonded together with the resin adhesive Single Bond and Rely X luting composite. A 500-g load was applied for 5 minutes and the samples were light-cured for 40s. The bonded blocks were serially sectioned into 3 slabs with 0.9mm of thickness perpendicularly to the bonded interface (n = 12). Slabs were trimmed to a dumbbell shape and tested in tension at 0.5mm/min. For all composites tested, the application of a silane primer after sandblasting provided the highest bond strength means.

  4. Degree of conversion of different composite resins photo-activated with light-emitting diode and argon ion laser

    Science.gov (United States)

    Messias, A. M.; Galvão, M. R.; Boaventura, J. M. C.; Jacomassi, D. P.; Bernardi, M. I. B.; Bagnato, V. S.; Rastelli, A. N. S.; Andrade, M. F.

    2015-02-01

    This study evaluated the degree of conversion (DC%) of one experimental and different brands of composite resins light-cured by two light sources (one LED and one argon laser). The percentage of unreacted C = C was determined from the ratio of absorbance intensities of aliphatic C = C (peak at 1637 cm-1) against internal standards before and after curing: aromatic C-C (peak at 1610 cm-1) except for P90, where %C = C bonds was given for C-O-C (883 cm-1) and C-C (1257 cm-1). ANOVA and Tukey’s test revealed no statistically significant difference among Z350 (67.17), Z250 (69.52) and experimental (66.61  ±  2.03) with LED, just among them and Evolu-X (75.51) and P90 (32.05) that showed higher and lower DC%, respectively. For the argon laser, there were no differences among Z250 (70.67), Z350 (69.60), experimental (65.66) and Evolu-X (73, 37), however a significant difference was observed for P90 (36.80), which showed lowest DC%. The light sources showed similar DC%, however the main difference was observed regarding the composite resins. The lowest DC% was observed for the argon laser. P90 showed the lowest DC% for both light-curing sources.

  5. Penumpatan Lesi Abrasi Servikal dengan "Light-Cured Glass Ionomer Cement" (Laporan Kasus

    Directory of Open Access Journals (Sweden)

    Gatot Sutrisno

    2015-10-01

    Full Text Available Penumpatan cacat gigi pada daerah servikal dengan bahan tumpat sewarna gigi masih banyak mengalami masalah. Beberapa bahan tumpat mulai dari semen silikat sampai dengan resin komposit masih belum memberikan kepuasan bagi para dokter gigi. Silikat banyak menimbulkan kematian terhadap jaringan pulpa karena daya iritasinya yang sangat besar, dan resin komposit banyak mengalami kegagalan dalam retensinya.Semen ionomer gelas memberikan harapan yang baik walaupun pada generasi pertama menunjukkan hasil yang tidak memuaskan."Light-cured glass-ionomer cement" yang merupakan pengembangan semen ionomer gelas konvensional menunjukkan hasil yang baik dalam retensi, estetika, dan sifatnya yang cocok terhadap jaringan keras gigi dan pulpa. Pada penumpatan lesi abrasi daerah servikal dengan "light-cured glass-ionomer cement" menunjukkan hasil yang sangat baik untuk menghilangkan gejala hipersensitivitas, retensi, dan estetikanya setelah kontrol selama 3 minggu. Evaluasi dalam waktu mendatang sangat perlu guna melihat penampilan klinis dan efeknya terhadap jaringan pulpa untuk mendukung penggunaan bahan ini secara luas.

  6. Comparison of the hardness and bond strength of different composite resin materials%不同复合树脂材料硬度及黏结强度的比较

    Institute of Scientific and Technical Information of China (English)

    王南燕; 张辉燕

    2015-01-01

    BACKGROUND:Compared with the conventional composite resin materials, large pieces of filing composite resin materials have the features of increasing light-curing depth, decreasing the polymerization shrinkage rate and streamlining operational procedures; however, the properties of different types of large pieces of filing composite resin materials are different. OBJECTIVE:To analyze the hardness and bond strength of four kinds of composite resin materials. METHODS: Large pieces of filing composite resin Tetric EvoCeram Bulk Fil, SDR, as wel as conventional composite resin P60, Z350 were obtained. The vickers microhardness of these four kinds of composite resin materials under the light-curing depth of 2, 3, 4, 5 mm was detected. The shear bond strength between these four kinds of composite resin materials and the dentin was also detected. RESULTS AND CONCLUSION:The hardness order under different light-curing depths was: P60 composite resin > Z350 composite resin > Tetric EvoCeram BulkFil composite resin > SDR composite resin, there was a significant difference between these four groups (P Z350复合树脂>Tetric EvoCeram BulkFil复合树脂> SDR复合树脂,4组间比较差异有显著性意义(P <0.05);Tetric EvoCeram BulkFill和SDR复合树脂光固化后的硬度未随着固化深度的增加而明显减小。Tetric EvoCream BulkFil和SDR复合树脂的剪切黏结强度显著高于P60和Z350复合树脂(P <0.05)。表明大块充填树脂材料Tetric EvoCeram BulkFil和SDR的综合机械性能较高,并且具有较高的剪切黏结强度。

  7. Fluorinated Alkyl Ether Epoxy Resin Compositions and Applications Thereof

    Science.gov (United States)

    Wohl, Christopher J. (Inventor); Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Siochi, Emilie J. (Inventor); Gardner, John M. (Inventor); Palmieri, Frank M. (Inventor)

    2017-01-01

    Epoxy resin compositions prepared using amino terminated fluoro alkyl ethers. The epoxy resin compositions exhibit low surface adhesion properties making them useful as coatings, paints, moldings, adhesives, and fiber reinforced composites.

  8. Polymerization shrinkage and depth of cure of bulk-fill resin composites and highly filled flowable resin.

    Science.gov (United States)

    Jang, J-H; Park, S-H; Hwang, I-N

    2015-01-01

    The aim of this study was to evaluate the polymerization behavior and depth of cure (DOC) of recently introduced resin composites for posterior use: highly filled flowable composite and composites for bulk fill. A highly filled flowable (G-aenial Universal Flo [GUF]), two bulk-fill flowables (Surefil SDR Flow [SDR] and Venus Bulk fill [VBF]), and a bulk-fill nonflowable composite (Tetric N-Ceram Bulk fill [TBF]) were compared with two conventional composites (Tetric Flow [TF], Filtek Supreme Ultra [FS]). Linear polymerization shrinkage and polymerization shrinkage stress were each measured with custom-made devices. To evaluate DOC, the composite specimen was prepared using a mold with a hole of 4 mm depth and 4 mm internal diameter. The hole was bulk filled with each of the six composites and light cured for 20 seconds, followed by 24 hours of water storage. The surface hardness was measured on the top and the bottom using a Vickers microhardness (HV) indenter. The linear polymerization shrinkage of the composite specimens after photo-initiation decreased in the following order: TF and GUF > VBF > SDR > FS and TBF (pcomposite groups decreased in the following order: GUF > TF and VBF > SDR > FS and TBF (pflowable (GUF) revealed limitations in polymerization shrinkage and DOC. Bulk-fill flowables (SDR and VBF) were properly cured in 4-mm bulk, but they shrank more than the conventional nonflowable composite. A bulk-fill nonflowable (TBF) showed comparable shrinkage to the conventional nonflowable composite, but it was not sufficiently cured in the 4-mm bulk.

  9. Flexural and diametral tensile strength of composite resins

    Directory of Open Access Journals (Sweden)

    Álvaro Della Bona

    2008-03-01

    Full Text Available This study evaluated the flexural strength (sf and the diametral tensile strength (st of light-cured composite resins, testing the hypothesis that there is a positive relation between these properties. Twenty specimens were fabricated for each material (Filtek Z250- 3M-Espe; AM- Amelogen, Ultradent; VE- Vit-l-escence, Ultradent; EX- Esthet-X, Dentsply/Caulk, following ISO 4049 and ANSI/ADA 27 specifications and the manufacturers’ instructions. For the st test, cylindrical shaped (4 mm x 6 mm specimens (n = 10 were placed with their long axes perpendicular to the applied compressive load at a crosshead speed of 1.0 mm/min. The sf was measured using the 3-point bending test, in which bar shaped specimens (n = 10 were tested at a crosshead speed of 0.5 mm/min. Both tests were performed in a universal testing machine (EMIC 2000 recording the fracture load (N. Strength values (MPa were calculated and statistically analyzed by ANOVA and Tukey (a = 0.05. The mean and standard deviation values (MPa were Z250-45.06 ± 5.7; AM-35.61 ± 5.4; VE-34.45 ± 7.8; and EX-42.87 ± 6.6 for st; and Z250-126.52 ± 3.3; AM-87.75 ± 3.8; VE-104.66 ± 4.4; and EX-119.48 ± 2.1 for sf. EX and Z250 showed higher st and sf values than the other materials evaluated (p < 0.05, which followed a decreasing trend of mean values. The results confirmed the study hypothesis, showing a positive relation between the material properties examined.

  10. Contraction stresses of composite resin filling materials.

    Science.gov (United States)

    Hegdahl, T; Gjerdet, N R

    1977-01-01

    The polymerization shrinkage of composite resin filling materials and the tensile stresses developed when the shrinkage is restrained were measured in an in vitro experiment. This allows an estimation to be made of the forces exerted upon the enamel walls of cavities filled with the resin in the acid etch technique. The results indicate that the stresses acting on the enamel are low compared to the tensile strength of the enamel.

  11. PMR Resin Compositions For High Temperatures

    Science.gov (United States)

    Vannucci, Raymond D.

    1989-01-01

    Report describes experiments to identify polymer matrix resins suitable for making graphite-fiber laminates used at 700 degree F (371 degree C) in such applications as aircraft engines to achieve higher thrust-to-weight ratios. Two particular high-molecular-weight formulations of PMR (polymerization of monomer reactants) resins most promising. PMR compositions of higher FMW exhibit enhanced thermo-oxidative stability. Formation of high-quality laminates with these compositions requires use of curing pressures higher than those suitable for compositions of lower FMW.

  12. Effects of tributylborane-activated adhesive and two silane agents on bonding computer-aided design and manufacturing (CAD/CAM) resin composite.

    Science.gov (United States)

    Shinohara, Ayano; Taira, Yohsuke; Sawase, Takashi

    2017-01-09

    The present study was conducted to evaluate the effects of an experimental adhesive agent [methyl methacrylate-tributylborane liquid (MT)] and two adhesive agents containing silane on the bonding between a resin composite block of a computer-aided design and manufacturing (CAD/CAM) system and a light-curing resin composite veneering material. The surfaces of CAD/CAM resin composite specimens were ground with silicon-carbide paper, treated with phosphoric acid, and then primed with either one of the two silane agents [Scotchbond Universal Adhesive (SC) and GC Ceramic Primer II (GC)], no adhesive control (Cont), or one of three combinations (MT/SC, MT/GC, and MT/Cont). A light-curing resin composite was veneered on the primed CAD/CAM resin composite surface. The veneered specimens were subjected to thermocycling between 4 and 60 °C for 10,000 cycles, and the shear bond strengths were determined. All data were analyzed using analysis of variance and a post hoc Tukey-Kramer HSD test (α = 0.05, n = 8). MT/SC (38.7 MPa) exhibited the highest mean bond strengths, followed by MT/GC (30.4 MPa), SC (27.9 MPa), and MT/Cont (25.7 MPa), while Cont (12.9 MPa) and GC (12.3 MPa) resulted in the lowest bond strengths. The use of MT in conjunction with a silane agent significantly improved the bond strength. Surface treatment with appropriate adhesive agents was confirmed as a prerequisite for veneering CAD/CAM resin composite restorations.

  13. Light-Cured Self-Etch Adhesives Undergo Hydroxyapatite-Triggered Self-Cure.

    Science.gov (United States)

    Liu, Y; Bai, X; Liu, Y W; Wang, Y

    2016-03-01

    Light cure is a popular mode of curing for dental adhesives. However, it suffers from inadequate light delivery when the restoration site is less accessible, in which case a self-cure mechanism is desirable to salvage any compromised polymerization. We previously reported a novel self-cure system mediated by ethyl 4-(dimethylamino)-benzoate (4E) and hydroxyapatite (HAp). The present work aims to investigate if such self-cure phenomenon takes place in adhesives that underwent prior inadequate light cure and to elucidate if HAp released from the dental etching process is sufficient to trigger it. Model self-etch adhesives were formulated with various components, including bis[2-methacryloyloxy)ethyl]-phosphate (2MP) as acidic monomer and trimethylbenzoyl-diphenylphosphine oxide (TPO) as photoinitiator. In vitro evolution of degree of conversion (DC) of HAp-incorporated adhesives was monitored by infrared spectroscopy during light irradiation and dark storage. Selected adhesives were allowed to etch and extract HAp from enamel, light-cured in situ, and stored in the dark, after which Raman line mapping was used to obtain spatially resolved DC across the enamel-resin interface. Results showed that TPO+4E adhesives reached DC similar to TPO-only counterparts upon completion of light irradiation but underwent another round of initiation that boosted DC to ~100% regardless of HAp level or prior light exposure. When applied to enamel, TPO-only adhesives had ~80% DC in resin, which gradually descended to ~50% in enamel, whereas TPO+4E adhesives consistently scored ~80% DC across the enamel-resin interface. These observations suggest that polymerization of adhesives that underwent insufficient light cure is salvaged by the novel self-cure mechanism, and such salvaging effect can be triggered by HAp released from dental substrate during the etching process.

  14. Advances in the history of composite resins.

    Science.gov (United States)

    Minguez, Nieves; Ellacuria, Joseba; Soler, José Ignacio; Triana, Rodrigo; Ibaseta, Guillermo

    2003-11-01

    The use of composite resins as direct restoration material in posterior teeth has demonstrated a great increase, due to esthetic requirements and the controversy regarding the mercury content in silver amalgams. In this article, we have reviewed the composition modifications which have occurred in materials based on resins since their introduction over a half a century ago which have enabled great improvements in their physical and mechanical properties. Likewise, we have highlighted current lines of research, centered on finding the ideal material for replacing silver amalgam as a direct filling material.

  15. Shear bond strength between porcelain and nano filler composite resin with or without 9% hydrofluoric acid etching

    Directory of Open Access Journals (Sweden)

    Kun Ismiyatin

    2009-06-01

    Full Text Available Background: Reparation technique on restorations with broken or damaged porcelain which are still attached with the teeth are difficult, because it is very hard to remove the porcelain restoration without damaging it, and it needs a long time. Various ways have been developed to repair the broken porcelain, one of them is the use of composite resin as the material for the restoration of fractured porcelain. Repairing porcelain inside the mouth without removing the restoration of the damaged porcelain using light cured composite resins material seems to be an advantageous option because it is relatively simple, has low risks, good esthetically and cheap. Purpose: The objective of this study was to find out the difference of shear bond strength in porcelain reparation using nano filler composite resin with or without 9% hydrofluoric acid etching by using Autograph measuring device. Methods: Twenty pieces of the porcelain samples devided into 2 groups. Group I: etching process using 9% hydrofluoric acid, and group II : without etching process. Result: The data was analyzed using t test in a p value of 0.0001 (p≤0.05, which means there is a significant different of shear bond strength between treated group I and II. The biggest shear bond strength was in treatment group I. Conclusion: The use of 9% hydrofluoric acid on the surface of porcelain can increase the shear bond strength between porcelain and nano filler composite resin.

  16. 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...

  17. Retention of a Flowable Composite Resin in Comparison to a Conventional Resin-Based Sealant: One-year Follow-up

    Directory of Open Access Journals (Sweden)

    N. Tadayon

    2010-03-01

    Full Text Available Objective: Long-term retention of pit and fissure sealants is crucial for their success. This clinical study evaluated the retention rate of a flowable composite resin (Filtek SupremeXT Flowable Restorative compared to a conventional resin-based sealant (Concise Light Cure White Sealant over 12 months.Materials and Methods: Forty subjects aged 6 to 9 years were included in the study. Using a half-mouth design, a total of 80 first permanent molars were sealed with conventional fissure sealant on one side of the mouth and flowable composite on the contralateralside. Clinical evaluation was performed at 3, 6, and 12 months by a single blind examiner and the retention was classified as complete retention, partial loss, or total loss.Results: For both materials, there was no total loss of sealants over 12 months. Partial loss of both materials was observed in one sealant after 3 months. After 6 months, 36 teeth sealed with conventional fissure sealant were intact compared with 37 sealed with a flowable composite, and after 12 months, 33 teeth sealed with conventional fissure sealant were intact compared with 35 that were sealed with a flowable composite. There were no statistically significant difference (P>0.05 between the two materials regarding the retention rate at each follow-up period.Conclusion: As flowable composite resulted in comparable sealant retention rates, this material could be a good choice for fissure sealant.

  18. Restoration of traumatized teeth with resin composites

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2017-01-01

    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...

  19. Extended Resin Composite Restorations: Techniques and Procedures

    NARCIS (Netherlands)

    Loomans, B.A.C.; Hilton, T.

    2016-01-01

    This article gives an overview of the state of the art of different restorative treatment procedures and techniques needed for placing extended posterior resin composite restorations. Clinical aspects related to the procedure are discussed and reviewed based on the current literature, such as the

  20. The influence of a packable resin composite, conventional resin composite and amalgam on molar cuspal stiffness.

    Science.gov (United States)

    Molinaro, J D; Diefenderfer, K E; Strother, J M

    2002-01-01

    Packable resin composites may offer improved properties and clinical performance over conventional resin composites or dental amalgam. This in vitro study examined the cuspal stiffness of molars restored with a packable resin composite, a conventional posterior microfilled resin composite and amalgam. Forty-eight intact caries-free human third molars were distributed into four treatment groups (n=12) so that the mean cross-sectional areas of all groups were equal. Standardized MOD cavity preparations were made and specimens restored using one of four restorative materials: (1) a spherical particle amalgam (Tytin); (2) Tytin amalgam with a dentin adhesive liner (OptiBond Solo); (3) a conventional microfilled posterior resin composite (Heliomolar); (4) a packable posterior resin composite (Prodigy Posterior). Cuspal stiffness was measured using a Bionix 200 biomaterials testing machine (MTS). Specimens were loaded vertically to 300 N at a crosshead speed of 1.0 mm/minute. Stiffness was measured at 10 intervals: (1) prior to cavity preparation (intact); (2) following cavity preparation, but before restoration; (3) seven days after restoration; then (4) 1, 2, 3, 4, 5, 6 and 12 months after restoration. All specimens were stored at 37 degrees C in deionized water throughout the study and thermocycled (5 degrees/55 degrees C; 2000 cycles) monthly for 12 months. Repeated Measures ANOVA revealed significant differences among treatment groups over time (presin composite increased cuspal stiffness over that of amalgam.

  1. 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.

  2. 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.

  3. 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 (pLEDs. 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.

  4. 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.

  5. Simulated fatigue resistance of composite resin versus porcelain CAD/CAM overlay restorations on endodontically treated molars.

    Science.gov (United States)

    Magne, Pascal; Knezevic, Alena

    2009-02-01

    To assess the influence of material selection (porcelain versus composite resin) for overlay-type restoration of endodontically treated molars and its effect on the in vitro fatigue resistance and failure mode. A standardized tooth preparation was applied to 30 extracted molars, including root canal treatment, 3-mm coverage of all cusps, a mesial box 1.5 mm below the cementoenamel junction (CEJ), a distal box in enamel, a glass-ionomer base, and immediately sealed dentin. Using the Cerec machine (Sirona), all teeth were restored with an overlay of standardized thickness and occlusal anatomy. Fifteen restorations were milled in the ceramic Vita MKII block (Vident) and the other 15 using the composite resin Paradigm MZ100 block (3M ESPE). The intaglio surfaces of the ceramic restorations were etched and silanated. The intaglio surfaces of the composite resin overlays were airborne-particle abraded and silanated. Preparations were airborne-particle abraded and etched before restoration insertion. All restorations were adhesively luted with an adhesive resin (Optibond FL, Kerr) and a light-curing composite resin (Filtek Z100, 3M ESPE). Cyclic isometric chewing (5 Hz) was simulated, starting with a load of 200 N (5,000 cycles), followed by stages of 400, 600, 800, 1,000, 1,200, and 1,400 N at a maximum of 30,000 cycles each. Samples were loaded until fracture or to a maximum of 185,000 cycles. MKII overlays fractured at a mean load of 1,147 N, and none of them withstood all 185,000 loading cycles (survival = 0%); with MZ100, the survival rate was 73%. With MKII, 40% of the fractures ended below the CEJ; with MZ100, only 25% did. Composite resin MZ100 increased the fatigue resistance of overlay-type restorations in endodontically treated molars when compared to porcelain MKII. The efficiency of the bond strategy (immediate dentin sealing) was demonstrated by the absence of adhesive failures.

  6. Color difference of composite resins after cementation with different shades of resin luting cement.

    Science.gov (United States)

    Cengiz, Esra; Kurtulmus-Yilmaz, Sevcan; Karakaya, Izgen; Aktore, Huseyin

    2017-07-26

    The purpose of this study was to evaluate the color difference of nanohybrid and ormocer-based composite resins with different thicknesses when 4 different shades of resin luting cement were used. 56 disc specimens of each composite resin (Aelite aesthetic enamel, Ceram-X mono) with 0.5 and 1 mm thicknesses were fabricated. Baseline color measurements were performed using a clinical spectrophotometer. The specimens of each thicknesses of each resin were randomly divided into 4 groups according to the shades of resin luting cement (white/A1, yellow/universal/A3, transparent and white opaque) (n = 7). Mixed resin cement was applied onto the resin specimens using a Teflon mold in 0.1 mm thickness. Color measurements of cemented composite resin specimens were repeated and color difference (∆E) between baseline and after cementation measurements was calculated. ANOVA and Tukey's test were used for statistical analysis. The opaque shade had significantly increased ∆E values as compared to the other shades (p resins in terms of ∆E values. The shade of resin cement and the type of the resin affected the final color; however, the thickness of composite resin had no influence on the final color of restoration. Selecting the shade of resin luting cement before cementation of indirect composite laminate restoration is important to achieve final color match.

  7. Effects of preheating and precooling on the hardness and shrinkage of a composite resin cured with QTH and LED.

    Science.gov (United States)

    Osternack, F H; Caldas, D B M; Almeida, J B; Souza, E M; Mazur, R F

    2013-01-01

    The aim of this study was to evaluate in vitro the hardness and shrinkage of a pre-cooled or preheated hybrid composite resin cured by a quartz-tungsten-halogen light (QTH) and light-emitting diode (LED) curing units. The temperature on the tip of the devices was also investigated. Specimens of Charisma resin composite were produced with a metal mold kept under 37°C. The syringes were submitted to 4°C, 23°C, and 60°C (n=20) before light-curing, which was carried out with the Optilux 501 VCL and Elipar FreeLight 2 units for 20 seconds. The specimens were kept under 37°C in a high humidity condition and darkness for 48 hours. The Knoop hardness test was carried out with a 50 gram-force (gf) load for 10 seconds, and the measurement of the shrinkage gap was carried out using an optical microscope. The data were subjected to analysis of variance and the Games-Howell test (α=0.05). The mean hardness of the groups were similar, irrespective of the temperatures (p>0.05). For 4°C and 60°C, the top surface light-cured by LED presented significantly reduced shrinkage when compared with the bottom and to both surfaces cured by QTH (phardness was not affected by pre-cooling or preheating. However, polymerization shrinkage was slightly affected by different pre-polymerization temperatures. The QTH-curing generated greater shrinkage than LED-curing only when the composite was preheated. Different temperatures did not affect the composite hardness and shrinkage when cured by a LED curing unit.

  8. Shear bond strength between alumina substrate and prosthodontic resin composites with various adhesive resin systems.

    Science.gov (United States)

    AlJehani, Yousef A; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Vallittu, Pekka K

    2015-05-02

    With the increase in demand for cosmetics and esthetics, resin composite restorations and all-ceramic restorations have become an important treatment alternative. Taking into consideration the large number of prosthodontic and adhesive resins currently available, the strength and durability of these materials needs to be evaluated. This laboratory study presents the shear bond strengths of a range of veneering resin composites bonded to all-ceramic core material using different adhesive resins. Alumina ceramic specimens (Techceram Ltd, Shipley, UK) were assigned to three groups. Three types of commercially available prosthodontic resin composites [BelleGlass®, (BG, Kerr, CA, USA), Sinfony® (SF, 3 M ESPE, Dental Products, Germany), and GC Gradia® (GCG, GC Corp, Tokyo, Japan)] were bonded to the alumina substrate using four different adhesive resins. Half the specimens per group (N = 40) were stored dry for 24 hours, the remaining were stored for 30 days in water. The bonding strength, so-called shear bond strengths between composite resin and alumina substrate were measured. Data were analysed statistically and variations in bond strength within each group were additionally evaluated by calculating the Weibull modulus. Bond strengths were influenced by the brand of prosthodontic resin composites. Shear bond strengths of material combinations varied from 24.17 ± 3.72-10.15 ± 3.69 MPa and 21.20 ± 4.64-7.50 ± 4.22 at 24 h and 30 days, respectively. BG resin composite compared with the other resin composites provided the strongest bond with alumina substrate (p resin composite was found to have a lower bond strength than the other composites. The Weibull moduli were highest for BG, which was bonded by using Optibond Solo Plus adhesive resin at 24 h and 30 days. There was no effect of storage time and adhesive brand on bond strength. Within the limitations of this study, the shear bond strengths of composite resins to alumina substrate are related to the composite

  9. Effect of resin matrix ratio, storage medium, and time upon the physical properties of a radiopaque dental composite.

    Science.gov (United States)

    Deepa, C S; Krishnan, V K

    2000-01-01

    Three light curing composite pastes with varying resin matrix ratios [bisphenol A-glycidyl methacrylate (BIS-GMA)/urethane tetramethacrylate (UTMA) 25:75, BIS-GMA/UTMA 50:50, and BIS-GMA/UTMA 75:25 w/w%] were prepared in combination with a radiopaque glass powder and camphorquinone photoinitiator. Cured samples were aged at 37 degrees C in three food simulating media such as citrate buffer (pH 4.0), PBS buffer (pH 7.4), and 75% ethyl alcohol. Samples were withdrawn at specific intervals of 1, 15, 30, 45, and 60 days and tested for changes in mechanical properties, sorption, and solubility characteristics. Statistical calculations revealed significant changes in compressive strength (CS) for composites depending on the resin matrix ratio and type of medium used for aging. While diametral tensile strength (DTS) was affected adversely in citrate medium for composites with higher urethane content, samples stored in alcohol medium showed deterioration of transverse strength (TS) and microhardness (VMH) for all composites studied. Increase in BIS-GMA content in the resin matrix and storage in alcohol medium resulted in higher sorption and solubility values and lower microhardness.

  10. effect of light curing unit characteristics on light intensity output ...

    African Journals Online (AJOL)

    2013-09-09

    Sep 9, 2013 ... Objective: To determine the characteristics of light curing units (LCUs) in dental clinics in Nairobi and ... generation which has dogged the new generation of. LEDs without ..... Knezevic A, Tarle Z, Meniga A, Sutalo J, Pichler G.

  11. Light-Curing Adhesive Repair Tapes

    Science.gov (United States)

    Allred, Ronald; Haight, Andrea Hoyt

    2009-01-01

    Adhesive tapes, the adhesive resins of which can be cured (and thereby rigidized) by exposure to ultraviolet and/or visible light, are being developed as repair patch materials. The tapes, including their resin components, consist entirely of solid, low-outgassing, nonhazardous or minimally hazardous materials. They can be used in air or in vacuum and can be cured rapidly, even at temperatures as low as -20 C. Although these tapes were originally intended for use in repairing structures in outer space, they can also be used on Earth for quickly repairing a wide variety of structures. They can be expected to be especially useful in situations in which it is necessary to rigidize tapes after wrapping them around or pressing them onto the parts to be repaired.

  12. New Resins for Dental Composites.

    Science.gov (United States)

    Fugolin, A P P; Pfeifer, C S

    2017-09-01

    Restorative composites have evolved significantly since they were first introduced in the early 1960s, with most of the development concentrating on the filler technology. This has led to improved mechanical properties, notably wear resistance, and has expanded the use of composites to larger posterior restorations. On the organic matrix side, concerns over the polymerization stress and the potential damage to the bonded interface have dominated research in the past 20 y, with many "low-shrinkage" composites being launched commercially. The lack of clinical correlation between the use of these materials and improved restoration outcomes has shifted the focus more recently to improving materials' resistance to degradation in the oral environment, caused by aqueous solvents and salivary enzymes, as well as biofilm development. Antimicrobial and ester-free monomers have been developed in the recent past, and evidence is mounting for their potential benefit. This article reviews literature on the newest materials currently on the market and provides an outlook for the future developments needed to improve restoration longevity past the average 10 y.

  13. Influence of different light-curing units on the surface roughness of restorative materials: in situ study

    Directory of Open Access Journals (Sweden)

    Juliane Cristina Ciccone-Nogueira

    2007-09-01

    Full Text Available The aim of this study was to evaluate the influence of different light sources (LED and Halogen lamp on the roughness (superficial of composite resin (Filtek Z250, Filtek P60, Charisma and Durafill varying post-irradiation times, in an in situ experiment. For this purpose, 80 specimens were made in polyurethane moulds. Ten volunteers without medicament use and good oral condition were selected and from them study moulds were obtained. A palatal intra-oral acrylic resin appliance was made for each of the subjects of the experiment. In each appliance, two specimens of each material were fixed (LED/Halogen lamp - control group. Roughness tests were performed immediately and 30 days after initial light-curing. Statistical analysis was performed using ANOVA. Statistically significant difference was observed only between post-irradiation times, where the 30th day showed the highest roughness values. It be concluded that roughness was influenced only by post-irradiation times, presenting the 30- days period inferior behavior.

  14. Properties of magnetically attractive experimental resin composites.

    Science.gov (United States)

    Hirano, S; Yasukawa, H; Nomoto, R; Moriyama, K; Hirasawa, T

    1996-12-01

    SUS444 stainless steel filled chemically cured resin composites that can attract magnet were fabricated. The filler was treated with various concentrations of silane. The experimental composite was easy to handle and showed a good shelf life. The maximal properties obtained are as follows; The attraction force to a magnetic attachment was 1/3-1/4 lower than the commercially available magnet-keeper system for dental magnetic attachment. Flexural strength and Knoop hardness of the composite were 76MPa (7.7 kgf/mm2) and 64 KHN. These values were lower than the commercially available chemically cured composite used as a reference. Eluted metal from the composite in 1% lactic acid solution for 7 days showed 0.7 mg/cm2, but in 0.9% NaCl solution for 7 days, it could not be detected.

  15. Silanising agents promote resin-composite repair.

    Science.gov (United States)

    Staxrud, Frode; Dahl, Jon E

    2015-12-01

    The aim of this study was to investigate the effect of silane in the repair of old and new resin-composite restorations. Part 1: repair of old composite was performed on 60 resin-composite substrates that were 6 years old and were made of six different brands of composite. Three experiments were performed. In the first experiment, the substrates were ground flat and composite was fixed to the surface with bonding agent without silane (i.e. Clearfil Bond SE only, the control). Shear bond strength (SBS) was tested according to ISO/TS 11405 after thermocycling. In the second experiment, the same 60 substrates were ground again and treated with bis-silane a 2-part silane mixed shortly before application before applying bonding agent (Clearfil Bond SE plus silane) and repair composite before SBS testing. In the third experiment, the same substrates were ground again and a one-step bonding product containing silane (Scotchbond Universal bond containing silane) was used for the repair procedure before SBS testing. Part 2: to evaluate the repair of newly made composite restorations, 66 composite substrates were made and stored in water for 2 months. The specimens were divided into three groups and were tested using the same protocols as used to evaluate repair of old composite. Mean SBS (± standard deviation), in MPa, for repair of old composite was 6.2 ± 4.0 (Clearfil Bond SE only, control), 14.8 ± 7.8 (Clearfil Bond SE plus silane) and 15.3 ± 5.6 (Scotchbond Universal bond with silane), whereas for new composite mean SBS was 15.4 ± 8.6 (Clearfil Bond SE only, control), 23.4 ± 8.3 (Clearfil Bond SE with silane) and 23.7 ± 5.8 (Scotchbond Universal containing silane). A significant difference was observed between the control and the test groups with silanising agents, both in Part 1 (P resin composite repair. © 2015 FDI World Dental Federation.

  16. 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

  17. 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; de BRITO-GONÇALVES, Joel; RASTELLI, Alessandra Nara de Souza; BAGNATO, Vanderlei Salvador; SAAD, José Roberto Cury

    2012-01-01

    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 FiltekTM 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

  18. Influence of aging solutions on wear resistance and hardness of selected resin-based dental composites.

    Science.gov (United States)

    Chladek, Grzegorz; Basa, Katarzyna; Żmudzki, Jarosław; Malara, Piotr; Nowak, Agnieszka J; Kasperski, Jacek

    2016-01-01

    The purpose of this study was to investigate the effect of different plasticizing aging solutions on wear resistance and hardness of selected universal resin-based dental composites. Three light cured (one nanofilled, two microhybride) and one hybride chemical cured composites were aged at 37 °C for 48 h in distillated water, ethyl alcohol solution or Listerine mouthwash. After aging the microhardness tests were carried out and then tribological tests were performed in the presence of aging solution at 37 °C. During wear testing coefficients of friction were determined. The maximal vertical loss in micrometers was determined with profilometer. Aging in all liquids resulted in a significant decrease in hardness of the test materials, with the largest values obtained successively in ethanol solution, mouthwash and water. The effect of the liquid was dependent on the particular material, but not the type of material (interpreted as the size of filler used). Introduction of mouthwash instead of water or ethanol solution resulted in a significant reduction in the coefficient of friction. The lowest wear resistance was registered after aging in ethanol and for the chemical cured hybrid composite, but the vertical loss was strongly material dependent. The effect of different aging solution, including commercial mouthrinse, on hardness and wear was material dependent, and cannot be deduced from their category or filler loading. There is no simple correlation between hardness of resin-based dental composites and their wear resistance, but softening of particular composites materials during aging leads to the reduction of its wear resistance.

  19. Design of a new, multi-purpose, light-curing adhesive comprising a silane coupling agent, acidic adhesive monomers and dithiooctanoate monomers for bonding to varied metal and dental ceramic materials.

    Science.gov (United States)

    Ikemura, Kunio; Tanaka, Hisaki; Fujii, Toshihide; Deguchi, Mikito; Negoro, Noriyuki; Endo, Takeshi; Kadoma, Yoshinori

    2011-01-01

    A newly designed, light-curing adhesive was investigated for its bonding effectiveness to porcelain, alumina, zirconia, Au, Au alloy, Ag alloy, Au-Ag-Pd alloy, and Ni-Cr alloy. Four experimental adhesives were prepared using varying contents of the following: a silane coupling agent [3-methacryloyloxypropyltriethoxysilane (3-MPTES)], acidic adhesive monomers [6-methacryloyloxyhexyl phosphonoacetate(6-MHPA),6-methacryloyloxyhexyl3-phosphonopropionate(6-MHPP)and 4-methacryloyloxyethoxycarbonylphthalic acid (4-MET)], and dithiooctanoate monomers [6-methacryloyloxyhexyl 6,8-dithiooctanoate (6-MHDT) and 10-methacryloyloxydecyl 6,8-dithiooctanoate (10-MDDT)]. After all adherend surfaces were sandblasted and applied with an experimental adhesive, shear bond strengths (SBSs) of a light-curing resin composite (Beautifil II, Shofu Inc., Kyoto, Japan) to the adherend materials after 2,000 times of thermal cycling were measured. For the experimental adhesive which contained 3-MPTES (30.0 wt%), 6-MHPA (1.0 wt%), 6-MHPP (1.0 wt%), 4-MET (1.0 wt%), 6-MHDT (0.5 wt%) and 10-MDDT (0.5 wt%), it consistently yielded the highest SBS for all adherend surfaces in the range of 20.8 (4.8)-30.3 (7.9) MPa, with no significant differences among all the adherend materials (p>0.05). Therefore, the newly designed, multi-purpose, light-curing adhesive was able to deliver high SBS to all the adherend materials tested.

  20. Comparison of Cashew Nut Shell Liquid (CNS Resin with Polyester Resin in Composite Development

    Directory of Open Access Journals (Sweden)

    C. C. Ugoamadi

    2013-12-01

    Full Text Available Natural resins can compete effectively with the synthetic ones in composite development. In this research, cashew nuts were picked and processed for the extraction of the resin content. The resin (natural resin so obtained was mixed with cobalt amine (accelerator, methyl ethyl ketone peroxide (catalyst to develop two sets of composite specimens – specimens without fibres and specimens reinforced with glass fibres. This method of sample specimen development was repeated with polyester (synthetic resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate compressive strength of 55MPa compared to that of polyester resin with an ultimate strength of 68MPa. The result of tensile strength proved cashew nut shell liquid resin (with ultimate strength of 44MPa to be better than polyester resin with 39MPa as ultimate tensile strength. This means that natural resins could be a better substitute for the synthetic ones when the required quantities of fibers (reinforcements and fillers are used in the fibre-reinforced plastic composite developments.

  1. 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.

  2. Conventional and microfilled composite resins. Part II. Chip fractures.

    Science.gov (United States)

    Lambrechts, P; Ameye, C; Vanherle, G

    1982-11-01

    Dentists are accustomed to advantages and disadvantages in the materials at their disposal. This article was concerned with one disadvantage of microfilled composite resins, namely, chip fractures. Probably due to their higher coefficient of thermal expansion, higher water sorption, higher polymerization shrinkage, and lower tensile strengths, cohesive as well as adhesive chip fractures occur three to four times more often with microfilled composite resins than with conventional composite resins. Microfilled composite resins are indicated for esthetic purposes. They are contraindicated for Class IV and stress-bearing restorations. They are indicated for limited use in Class I restorations where esthetics is of primary importance. The technique of use must include acid-etching and intermediate bonding. The microfilled composite resins enjoy a smooth finish and high luster. This offers advantages in areas where smoothness is paramount. They may replace conventional composite resins for resurfacing existing restorations and veneering stained or mottled anterior teeth. They are indicated for treatment of cervical erosion.

  3. Candida albicans adhesion to composite resin materials.

    Science.gov (United States)

    Bürgers, Ralf; Schneider-Brachert, Wulf; Rosentritt, Martin; Handel, Gerhard; Hahnel, Sebastian

    2009-09-01

    The adhesion of Candida albicans to dental restorative materials in the human oral cavity may promote the occurrence of oral candidosis. This study aimed to compare the susceptibility of 14 commonly used composite resin materials (two compomers, one ormocer, one novel silorane, and ten conventional hybrid composites) to adhere Candida albicans. Differences in the amount of adhering fungi should be related to surface roughness, hydrophobicity, and the type of matrix. Cylindrical specimens of each material were made according to the manufacturers' instructions. Surface roughness R (a) was assessed by perthometer measurements and the degree of hydrophobicity by computerized contact angle analysis. Specimens were incubated with a reference strain of C. albicans (DMSZ 1386), and adhering fungi were quantified by using a bioluminometric assay in combination with an automated plate reader. Statistical differences were analyzed by the Kruskal-Wallis test and Mann-Whitney U test. Spearman's rank correlation coefficients were calculated to assess correlations. Median R (a) of the tested composite resin materials ranged between 0.04 and 0.23 microm, median contact angles between 69.2 degrees and 86.9 degrees . The two compomers and the ormocer showed lower luminescence intensities indicating less adhesion of fungi than all tested conventional hybrid composites. No conclusive correlation was found between surface roughness, hydrophobicity, and the amount of adhering C. albicans.

  4. [Classification and several mechanical properties of core composite resins].

    Science.gov (United States)

    Yamada, T; Hosoda, H; Tsurugai, T

    1990-03-01

    According to the classification proposed by Hosoda, six core resins could be divided into two categories on the basis of the elemental composition and size distribution of filler particles by SEM observation and EDX analysis. Furthermore, several mechanical properties of the resins were determined. The following facts were found: Bell Feel Core, Clearfil Core, Clearfil PhotoCore, Core Max, and Core Max II resins were classified as a semihybrid resin, and Microrest Core resin as a hybrid type resin. The elements detected in the resins by the EDX were Si, Zr, Al, Ba and La. The mechanical properties of the resins were shown to be highly stable at one day or one week after curing. The mechanical properties of the resins suggest that the subsequent crown preparation and impression taking should be postponed until the next appointment.

  5. The effect of curing units and methods on degree of conversion of two types of composite resins

    Directory of Open Access Journals (Sweden)

    Hasani Tabatabaei M

    2007-06-01

    Full Text Available Background and Aim: Halogen lamp is the commonly used light source for composite photo polymerization. Recently, high power halogen lamps, LED and plasma arc are introduced for improving the polymerization. The aim of this study was to investigate the effect of conventional and high power halogen lamps and LED light curing unit on degree of conversion of two different composite resins.Materials and Methods: In this in vitro experimental study two halogen units (Coltolux 50 with the intensity of  330 mW/cm2 and Optilux 501 with two different operating modes of standard with the intensity of 820 mW/cm2 and Ramp with the intentsiy of 100-1030mW/cm2 and one LED light curing unit (620 mW/cm2 were used. The composites were hybrid (Tetric ceram and nanofilled (Filteke supreme. Each materials/curing method contained three samples and degree of conversion (DC was measured with FTIR. Data were analyzed statistically with one way and two way ANOVA, Tukey HSD. P<0.05 was considered as the limit of significance.Results: Tetric ceram revealed higher DCthan Supreme. Tetric ceram showed a significant decrease in DC when Coltolux 50 was used in comparison to LED and Optilux 501. The latters did not show significant effect on DC of this material. DC of Supreme polymerized with various curing modes was not significantly different.Conclusion: Based on the results of this study, degree of conversion in hybrid composites was higher than nanofilled. In comparison with conventional halogen lamp (Coltolux 50, high intensity halogen lamps and LED unit significantly lead to higher degree of conversion in hybrid composites.

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

    Science.gov (United States)

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

    2017-09-28

    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 (ΔE00 )] 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.

  7. Evaluation of Resin-Resin Interface in Direct Composite Restoration Repair

    Science.gov (United States)

    Stoleriu, S.; Andrian, S.; Pancu, G.; Nica, I.; Iovan, G.

    2017-06-01

    The aim of this study was to evaluate the resin-resin interface when a universal bonding agent was used in two different strategies in direct restoration repair. Two composite resins (a micro-filled hybrid and a nano-filled hybrid) as old restorations that have to be repair, a universal bonding agent and a micro-filled hybrid composite resin (different then that aged) as new material for repair were chosen for the study. Non-aged samples were used as control and aged samples were used as study groups. The universal bonding agent was applied in etch-and-rinse and in self-etch strategies. The interface between old and new composite resins was evaluated by SEM and the microleakage was assessed by scoring the dye penetration. Very good adaptation of the two different composite resins placed in direct contact in non-aged samples was recorded. No gaps or defects were visible and strong resin-resin contact was observed. After aging, enlargement of resin-resin junction were observed in most of the samples and a increased dye penetration was recorded irrespective of the strategy (etch-and-rinse or self-etch) used for bonding agent application.

  8. 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

  9. Has resin-based composite replaced amalgam?

    Science.gov (United States)

    Christensen, Gordon J; Child, Paul L

    2010-02-01

    The major health organizations in the world continue to accept amalgam use, but the "amalgam war" of the 1800s is still going on. The end is not in sight. There is little disagreement that amalgam serves well and, although controversial, it appears to have minimal to no health hazards. There is a wide variation in the relative amount of amalgam placed in developed countries, and many dentists in North America do not use it. However, amalgam is still being used at least some of the time by the majority of practitioners in North America, and most of those practitioners also place resin-based composite in Class II locations. The evolution from amalgam to tooth-colored restorations has been a slow and tumultuous journey. The acceptability of resin-based composite in Class II locations continues to be a question for some dentists, while others have concluded that amalgam is "dead." It would be highly desirable if some of dentists using the alleged poisonous properties of amalgam as a "practice building" ploy would find more legitimate methods to increase their practice activity.

  10. Synthesis and study of properties of dental resin composites with different nanosilica particles size.

    Science.gov (United States)

    Karabela, Maria M; Sideridou, Irini D

    2011-08-01

    The aim of this work was the synthesis of light-cured resin nanocomposites using nanosilica particles with different particle size and the study of some physical-mechanical properties of the composites. Various types of silica nanoparticles (Aerosil) with average particle size of 40, 20, 16, 14, and 7 nm, used as filler were silanized with the silane 3-methacryloxypropyl-trimethoxysilane (MPS). The total amount of silane used was kept constant at 10 wt% relative to the filler weight to ensure the complete silanization of nanoparticles. The silanizated silica nanoparticles were identified by FT-IR spectroscopy and thermogravimetric analysis (TGA). Then the silanized nanoparticles (55 wt%) were mixed with a photoactivated Bis-GMA/TEGDMA (50/50 wt/wt) matrix. Degree of conversion of composites was determined by FT-IR analysis. The static flexural strength and flexural modulus were measured using a three-point bending set up. The dynamic thermomechanical properties were determined by dynamic mechanical analyzer (DMA). Sorption, solubility and volumetric change were determined after storage of composites in water or ethanol/water solution 75 vol% for 30 days. The TGA for composites was performed in nitrogen atmosphere from 30 to 700 °C. As the average silica particle size decreases, the percentage amount of MPS attached on the silica surface increases. However, the number of MPS molecules attached on the silica surface area of 1 nm(2) is independent of filler particle size. As the average filler particles size decreases a progressive increase in the degree of conversion of composites and an increase in the amount of sorbed water is observed. The prepared composites containing different amount of silica filler, with different particle size, but with the same amount of silanized silica and organic matrix showed similar flexural strength and flexural modulus, except composite with the lowest filler particle size, which showed lower flexural modulus. Copyright © 2011

  11. 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

  12. Transmission of composite polymerization contraction force through a flowable composite and a resin-modified glass ionomer cement.

    Science.gov (United States)

    Castañeda-Espinosa, Juan Carlos; Pereira, Rosana Aparecida; Cavalcanti, Ana Paula; Mondelli, Rafael Francisco Lia

    2007-12-01

    The purpose of this study was to evaluate the individual contraction force during polymerization of a composite resin (Z-250), a flowable composite (Filtek Flow, FF) and a resin-modified glass ionomer cement (Vitrebond, VB), and the transmission of Z-250 composite resin polymerization contraction force through different thicknesses of FF and VB. The experiment setup consisted of two identical parallel steel plates connected to a universal testing machine. One was fixed to a transversal base and the other to the equipment's cross head. The evaluated materials were inserted into a 1-mm space between the steel plates or between the inferior steel plate and a previously polymerized layer of an intermediate material (either FF or VB) adhered to the upper steel plate. The composite resin was light-cured with a halogen lamp with light intensity of 500 mW/cm(2) for 60 s. A force/time graph was obtained for each sample for up to 120 s. Seven groups of 10 specimens each were evaluated: G1: Z-250; G2: FF; G3: VB; G4: Z-250 through a 0.5-mm layer of FF; G5: Z-250 through a 1-mm layer of FF; G6: Z-250 through a 0.5-mm of VB; G7: Z-250 through a 1-mm layer of VB. They were averaged and compared using one-way ANOVA and Tukey test at a = 0.05. The obtained contraction forces were: G1: 6.3N + 0.2N; G2: 9.8 + 0.2N; G3: 1.8 + 0.2N; G4: 6.8N + 0.2N; G5: 6.9N + 0.3N; G6: 4.0N + 0.4N and G7: 2.8N + 0.4N. The use of VB as an intermediate layer promoted a significant decrease in polymerization contraction force values of the restorative system, regardless of material thickness. The use of FF as an intermediate layer promoted an increase in polymerization contraction force values with both material thicknesses.

  13. Transmission of composite polymerization contraction force through a flowable composite and a resin-modified glass ionomer cement

    Directory of Open Access Journals (Sweden)

    Juan Carlos Castañeda-Espinosa

    2007-12-01

    Full Text Available The purpose of this study was to evaluate the individual contraction force during polymerization of a composite resin (Z-250, a flowable composite (Filtek Flow, FF and a resin-modified glass ionomer cement (Vitrebond, VB, and the transmission of Z-250 composite resin polymerization contraction force through different thicknesses of FF and VB. The experiment setup consisted of two identical parallel steel plates connected to a universal testing machine. One was fixed to a transversal base and the other to the equipment's cross head. The evaluated materials were inserted into a 1-mm space between the steel plates or between the inferior steel plate and a previously polymerized layer of an intermediate material (either FF or VB adhered to the upper steel plate. The composite resin was light-cured with a halogen lamp with light intensity of 500 mW/cm² for 60 s. A force/time graph was obtained for each sample for up to 120 s. Seven groups of 10 specimens each were evaluated: G1: Z-250; G2: FF; G3: VB; G4: Z-250 through a 0.5-mm layer of FF; G5: Z-250 through a 1-mm layer of FF; G6: Z-250 through a 0.5-mm of VB; G7: Z-250 through a 1-mm layer of VB. They were averaged and compared using one-way ANOVA and Tukey test at a = 0.05. The obtained contraction forces were: G1: 6.3N + 0.2N; G2: 9.8 + 0.2N; G3: 1.8 + 0.2N; G4: 6.8N + 0.2N; G5: 6.9N + 0.3N; G6: 4.0N + 0.4N and G7: 2.8N + 0.4N. The use of VB as an intermediate layer promoted a significant decrease in polymerization contraction force values of the restorative system, regardless of material thickness. The use of FF as an intermediate layer promoted an increase in polymerization contraction force values with both material thicknesses.

  14. 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....

  15. Bond Strength of Repaired Composite Resin Restorations

    Directory of Open Access Journals (Sweden)

    Rodrigo Máximo de ARAÚJO

    2007-05-01

    Full Text Available Purpose: To evaluate the bond strength of direct composite resins and composite repairs, using 3 different commercial brands - GI: Palfique Estelite Ó (Tokuyama, GII: Filtek Z350 (3M/ESPE and GIII: Te Econon (Ivoclar/Vivadent - and the use of AdperTM Single Bond 2 (3M/ESPE adhesive system at the base/repair interface. Method: Thirty conic bases (5 mm x 5 mm x 3 mm of each commercial brand of composite resin were fabricated. All bases of each group were submitted to a thermocycling regimen of 20,000 cycles (5ºC to 55ºC ± 2ºC, for 30 s. The bases of each group were randomly assigned to 3 sub-groups, in which a combination of the commercial brands was performed for the repairs. The specimens were stored in distilled water at 37°C during 7 days and were thereafter tested in tensile strength in a universal testing machine (EMIC - MEM 2000 with 500 kgf load cell running at a crosshead speed of 1.0 mm/min until fracture. Data in MPa were submitted to ANOVA and Tukey’s test (5%.Results: The following results were found: GI: Palfique Estelite Ó (11.22±4.00 MPa, Te Econom (12.03±3.47 MPa and Filtek Z350 (10.66±2.89 MPa; GII: Palfique Estelite Ó (8.88±2.04 MPa, Te Econom (7.77±1.64 MPa and Filtek Z350 (10.50±6.14 MPa; and GIII: Palfique Estelite Ó (8.41±2.50 MPa, Te Econom (12.33±3.18 MPa and Z350 (11.73±3.54 MPa.Conclusion: The bond strengths at the interface of the different composite resins submitted to repair were statistically similar regardless of the commercial brand.

  16. Assessment of Microleakage of a Composite Resin Restoration in Primary Teeth Following Class III Cavity Preparation Using Er, Cr: YSGG laser: An In Vitro Study

    Science.gov (United States)

    Subramaniam, Priya; Pandey, Annu

    2016-01-01

    Introduction: Marginal seal integrity is important for a successful adhesive dental restoration. Alterations caused by laser irradiation in the enamel and dentin surface can affect the marginal integrity of adhesive restorations. The aim of this study was to evaluate the microleakage of a composite resin restoration in primary teeth following laser irradiation of enamel and dentin. Methods: Forty freshly extracted sound human primary maxillary and mandibular anterior teeth were used in this study. The teeth were randomly divided into two groups (I and II), with 20 teeth in each. In group I, proximal cavities (Class III) were prepared using an airotor hand –piece and diamond bur. The cavities were etched for 15 seconds with 35% phosphoric acid gel, rinsed with water for 15 seconds, air dried and a bonding agent was applied onto the cavity surfaces and light cured for 20 seconds. The cavities were restored with composite resin and light cured for 40 seconds. In group II, proximal (Class III) cavities were prepared using Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) (Er,Cr:YSGG) (Biolaseiplus, wave length 2.78 μm). The cavity was then rinsed, air dried and without etching, a bonding agent was applied and light cured for 20 seconds. The cavities were restored in the same manner as that of group I. The treated teeth were mounted on acrylic resin blocks and were subjected to a thermocycling regimen. Following, the teeth were immersed in 2% methylene blue for 24 hours. The teeth were sectioned longitudinally in a bucco-lingual direction using a diamond disc at slow speed. The sections of all the groups were examined under a stereomicroscope for micro-leakage. Results: The mean scores for microleakage in group I was 1.95 ± 1.31 and in group II it was 1.4 ± 1.27. There was no significant difference between the two groups (P = 0.882). Conclusion: No significant difference in microleakage was noticed between the composite resin bonded to lased enamel and

  17. Glass Fiber Resin Composites and Components at Arctic Temperatures

    Science.gov (United States)

    2015-06-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited GLASS FIBER RESIN...3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE GLASS FIBER RESIN COMPOSITES AND COMPONENTS AT ARCTIC TEMPERATURES 5...public release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) Glass fiber reinforced composites (GFRC

  18. 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.

  19. Effect of light intensity and irradiation time on the polymerization process of a dental composite resin

    Directory of Open Access Journals (Sweden)

    Discacciati José Augusto César

    2004-01-01

    Full Text Available Polymerization shrinkage is a critical factor affecting the longevity and acceptability of dental composite resins. The aim of this work was to evaluate the effect of light intensity and irradiation time on the polymerization process of a photo cured dental composite resin by measuring the Vickers hardness number (VHN and the volumetric polymerization shrinkage. Samples were prepared using a dental manual light-curing unit. The samples were submitted to irradiation times of 5, 10, 20 and 40 s, using 200 and 400 mW.cm-2 light intensities. Vickers hardness number was obtained at four different moments after photoactivation (immediate, 1 h, 24 h and 168 h. After this, volumetric polymerization shrinkage values were obtained through a specific density method. The values were analyzed by ANOVA and Duncan's (p = 0.05. Results showed increase in hardness values from the immediate reading to 1 h and 24 h readings. After 24 h no changes were observed regardless the light intensities or activation times. The hardness values were always smaller for the 200 mW.cm-2 light intensity, except for the 40 s irradiation time. No significant differences were detected in volumetric polymerization shrinkage considering the light intensity (p = 0.539 and the activation time (p = 0.637 factors. In conclusion the polymerization of the material does not terminate immediately after photoactivation and the increase of irradiation time can compensate a lower light intensity. Different combinations between light intensity and irradiation time, i.e., different amounts of energy given to the system, have not affected the polymerization shrinkage.

  20. A four to six years follow-up of indirect resin composite inlays/onlays.

    Science.gov (United States)

    Leirskar, Jakob; Nordbø, Håkon; Thoresen, Nina Rygh; Henaug, Turid; von der Fehr, Frithjof Ramm

    2003-08-01

    The objective of this clinical survival study was to evaluate the performance of indirect resin composite inlays and onlays. Patients were recruited among the dental school clientele needing posterior approximal restorations and preferring esthetic restorations. Two clinical teachers and 6 trained students under supervision carried out the preparations, made impressions, and prepared stone casts. Inlays/onlays from Tetric, Z100, or Maxxim were light-cured and transferred to a light oven for secondary curing. At the 4 6 year recall, the inlays/onlays were evaluated using slightly modified US Public Health Service criteria, bitewing radiographs, and plastic dies based on replica impressions. All 25 treated patients with a total of 64 inlays/onlays presented for the assessment. The right-censored observation periods ranged from 48 to 75 months, with a mean of 59. With the exception of three failed inlays/onlays scored as 'D' (2 fractures, 1 caries), i.e. 5%, the majority were classified as successful. This was based on 43 'A' (optimal) and 18 'B' (acceptable) ratings, each of which represented the lowest rating for each individual restoration. The major reason for 'B' ratings was imperfect anatomical form, mostly absence of proximal contacts. The present clinical trial demonstrated that inlays/onlays made from Tetric, Z100, and Maxxim performed equally well over the 5-year period. Within the limits of this study it is concluded that the resin composite inlay/onlay technique should be considered as an alternative to direct fillings in the approximal posterior region.

  1. Abrasive wear and surface roughness of contemporary dental composite resin.

    Science.gov (United States)

    Han, Jian-min; Zhang, Hongyu; Choe, Hyo-Sun; Lin, Hong; Zheng, Gang; Hong, Guang

    2014-01-01

    The purpose of this study was to evaluate the abrasive wear and surface roughness of 20 currently available commercial dental composite resins, including nanofilled, supra-nanofilled, nanohybrid and microhybrid composite resins. The volume loss, maximum vertical loss, surface roughness (R(a)) and surface morphology [Scanning electron microscopy (SEM)] were determined after wear. The inorganic filler content was determined by thermogravimetric analysis. The result showed that the volume loss and vertical loss varied among the materials. The coefficients of determination (R(2)) of wear volume loss and filler content (wt%) was 0.283. SEM micrographs revealed nanofilled composites displayed a relatively uniform wear surfaces with nanoclusters protrusion, while the performance of nanohybrid composites varied. The abrasive wear resistance of contemporary dental composite resins is material-dependent and cannot be deduced from its category, filler loading and composite matrix; The abrasive wear resistance of some flowable composites is comparable to the universal/posterior composite resins.

  2. Effect of epoxy resin properties on the mechanical properties of carbon fiber/epoxy resin composites

    Energy Technology Data Exchange (ETDEWEB)

    He, Hong-Wei; Gao, Feng [Taiyuan Univ. of Technology (China). College of Materials Science and Engineering; Taiyuan Univ. of Technology (China). Key Laboratory of Interface Science and Engineering in Advanced Materials; Li, Kai-Xi [Chinese Academy of Sciences, Taiyuan, Shanxi (China). Key Laboratory of Carbon Materials

    2013-09-15

    Three kinds of epoxy resins, i.e. tetraglycidyl diaminodiphenyl methane (AG80), difunctional diglycidyl ether of bisphenol-A (E51) and novolac type epoxy resin (F46) were selected as matrices for carbon fiber/epoxy composites. The objective of this work is to study the mechanical properties of fiber/epoxy composites by using these three kinds of epoxy resins with different physical and chemical performance. The results show that the composites fabricated with AG80 present the best stiffness and the composites prepared with E5 1have the best toughness. The stiffness and toughness of the composites prepared with F46 are middle values located between those for AG80/epoxy and E51/epoxy composites. Thus, the mixed epoxy resin is a promising approach for industrial production. (orig.)

  3. Composites with improved fiber-resin interfacial adhesion

    Science.gov (United States)

    Cizmecioglu, Muzaffer (Inventor)

    1989-01-01

    The adhesion of fiber reinforcement such as high modulus graphite to a matrix resin such as polycarbonate is greatly enhanced by applying a very thin layer, suitably from 50 Angstroms to below 1000 Angstroms, to the surface of the fiber such as by immersing the fiber in a dilute solution of the matrix resin in a volatile solvent followed by draining to remove excess solution and air drying to remove the solvent. The thin layer wets the fiber surface. The very dilute solution of matrix resin is able to impregnate multifilament fibers and the solution evenly flows onto the surface of the fibers. A thin uniform layer is formed on the surface of the fiber after removal of the solvent. The matrix resin coated fiber is completely wetted by the matrix resin during formation of the composite. Increased adhesion of the resin to the fibers is observed at fracture. At least 65 percent of the surface of the graphite fiber is covered with polycarbonate resin at fracture whereas uncoated fibers have very little matrix resin adhering to their surfaces at fracture and epoxy sized graphite fibers exhibit only slightly higher coverage with matrix resin at fracture. Flexural modulus of the composite containing matrix resin coated fibers is increased by 50 percent and flexural strength by 37 percent as compared to composites made with unsized fibers.

  4. Shear Bond Strength between Fiber-Reinforced Composite and Veneering Resin Composites with Various Adhesive Resin Systems.

    Science.gov (United States)

    AlJehani, Yousef A; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Vallittu, Pekka K

    2016-07-01

    The aim of this research was to evaluate the shear bond strength of different laboratory resin composites bonded to a fiber-reinforced composite substrate with some intermediate adhesive resins. Mounted test specimens of a bidirectional continuous fiber-reinforced substrate (StickNet) were randomly assigned to three equal groups. Three types of commercially available veneering resin composites - BelleGlass®, Sinfony®, and GC Gradia® were bonded to these specimens using four different adhesive resins. Half the specimens per group were stored for 24 hours; the remaining were stored for 30 days. There were 10 specimens in the test group (n). The shear bond strengths were calculated and expressed in MPa. Data were analyzed statistically, and variations in bond strength within each group were additionally evaluated by calculating the Weibull modulus. Shear bond values of those composites are influenced by the different bonding resins and different indirect composites. There was a significant difference in the shear bond strengths using different types of adhesive resins (p = 0.02) and using different veneering composites (p composite resin exhibited the lowest shear bond strength values when used with the same adhesive resins. The adhesive mode of failure was higher than cohesive with all laboratory composite resins bonded to the StickNet substructure at both storage times. Water storage had a tendency to lower the bond strengths of all laboratory composites, although the statistical differences were not significant. Within the limitations of this study, it was found that bonding of the veneering composite to bidirectional continuous fiber-reinforced substrate is influenced by the brand of the adhesive resin and veneering composite. © 2015 by the American College of Prosthodontists.

  5. Micromechanical properties of veneer luting resins after curing through ceramics.

    Science.gov (United States)

    Oztürk, Elif; Hickel, Reinhard; Bolay, Sükran; Ilie, Nicoleta

    2012-02-01

    The aim of this study was to assess the performance of light-cured luting resin after curing under the ceramic restoration in comparison to dual-cured luting resin, by evaluating the micromechanical properties. Two hundred seventy thin luting composite films of ca. 170 μm in thickness were prepared by using two light-cured luting resins (Variolink Veneer, Ivoclar Vivadent; RelyX Veneer, 3M ESPE) and a dual-cured luting resin (Variolink II, Ivoclar Vivadent). The composites were cured by using a LED-unit (Bluephase®, Ivoclar Vivadent) with three different curing times (10, 20, and 30 s) under two ceramics (IPS e.max Press, Ivoclar Vivadent; IPS Empress® CAD, Ivoclar Vivadent) of different thicknesses (0, 0.75, and 2 mm). Forty-five groups were included, each containing six thin films. The samples were stored after curing for 24 h at 37°C by maintaining moisture conditions with distilled water. Micromechanical properties of the composites were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). For each sample, ten indentations were made, thus totalizing 60 measurements per group. Micromechanical properties of the luting resins were statistically analyzed (SPSS 17.0). Significant differences were observed between the micromechanical properties of the luting resins (p mechanical properties compared to the light-cured luting resins. The effect of luting resin type on the micromechanical properties of the luting resins was higher than the effect of curing time, ceramic type and ceramic thickness respectively (*The values of reference without ceramics for 30 s curing time).

  6. 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.

  7. Smile makeover utilizing direct composite resin veneers.

    Science.gov (United States)

    Koczarski, Michael

    2008-12-01

    Creating a beautiful smile is more than restoring a single tooth back to its proper form. One must take into account the entire aesthetic zone, along with the mechanics of restoring the teeth to proper form and function. To make this effort even more challenging, the clinician is in full control and completely accountable for making the direct composite resin restorations from which the smile is created. Patients usually won't critique the aesthetics of a posterior direct resin, but once we move into the visible smile (along with the fact that most cosmetic procedures are patient desire- and want-driven) we must be able to deliver what the patient expects. Preplanning the case and avoiding the "prep and pray" approach to the smile-design process is the cornerstone of success. Utilizing tools for the creation of the restorations, such as a preoperative wax-up and silicone putty matrix, help the clinician break the procedure down to individual restorations that when created in harmony with the pre-operative design or wax-up, will allow a final "smile design" to emerge with predictability without getting lost in the daunting task of creating the entire smile all at once. Proper use of ideal composite materials adds the final touch on creating realistic results that even the most discerning patients demand. Layering colors, utilizing differing opacities and translucencies within the restorative process, is a must. Having a "recipe" to follow simplifies the process and gives the clinician confidence that the final result will have that realistic look. All in all, the easiest way to handle a challenging case is to break it down into smaller and more manageable increments in order to ensure a predictable outcome.

  8. Dental repair material: a resin-modified glass-ionomer bioactive ionic resin-based composite.

    Science.gov (United States)

    Croll, Theodore P; Berg, Joel H; Donly, Kevin J

    2015-01-01

    This report documents treatment and repair of three carious teeth that were restored with a new dental repair material that features the characteristics of both resin-modified glass-ionomer restorative cement (RMGI) and resin-based composite (RBC). The restorative products presented are reported by the manufacturer to be the first bioactive dental materials with an ionic resin matrix, a shock-absorbing resin component, and bioactive fillers that mimic the physical and chemical properties of natural teeth. The restorative material and base/liner, which feature three hardening mechanisms, could prove to be a notable advancement in the adhesive dentistry restorative materials continuum.

  9. Color Stability of IDM Composite Resin

    Directory of Open Access Journals (Sweden)

    Ghavam M

    2000-06-01

    Full Text Available Discoloration of composite resins is considered to be a major factor in esthetic restoration"nfailures. The aim of this study was to evaluate color stability of IDM composite (both light and self cure"nsamples namely IL and IS, and to compare it with a self-cure composite (Degufill named DS and a light"ncure ormocer composite (Definite, called DL in the Report. 60 disk shaped samples of each composite"nwere prepared, according to ISO-7491. The samples were divided into 3 groups and aged as follows:"nA- (Control 7 days in dark 37°c chamber"nB- Foil covered and kept in 100% humidity, and 37°c in xenotest chamber for 24 hours, then transferred"nto a dark 37°c chamber for 6 more days."nC- Kept in 37°c, 100% humidity under the emission of xiiion lamp of xenotest chamber for 24 hours,"nand then transferred to 37°c dark chamber for 6 more days"nThe lightness and chromaticity values of samples were measured both before and after aging using a"nspectrophotometer (Data Flash. The total color changes as well as changes in lightness and chromaticity"nvalues were measured in the CIE L * a * b * scale, and analyzed. Color change was recorded to be"nsignificant in all samples after aging. The maximum change belonged to IL, which was significantly"ndifferent from DL and DS. It seems, in order to have a durable esthetic restoration using IDM, more"nscientific and professional consideration is needed in the production process.

  10. Clinical Evaluation of Indirect Composite Resin Restorations Cemented with Different Resin Cements.

    Science.gov (United States)

    Marcondes, Maurem; Souza, Niélli; Manfroi, Fernanda Borguetti; Burnett, Luiz Henrique; Spohr, Ana Maria

    2016-01-01

    To clinically evaluate the performance of indirect composite resin restorations cemented with conventional and self-adhesive resin cements over a 12-month period. Ten patients fulfilled all the inclusion criteria. Twenty-four composite resin restorations were performed using an indirect technique and cemented with a resin cement (RelyX ARC) or a self-adhesive resin cement (RelyX U100). Two independent evaluators analyzed the restorations using modified USPHS criteria after periods of two weeks and 6 and 12 months. Statistical significance between the cements at each timepoint was evaluated with the Wilcoxon test and between timepoints with the Mann-Whitney test, both at a significance level of 5%. Fisher's exact test was used to assess the occurrence of absolute failures. No statistically significant differences were found between the groups at the same timepoint nor between groups at different timepoints. The only significant difference was found for color match for both groups after 12 months. After 12 months, indirect composite resin restorations cemented with self-adhesive resin cement performed similarly to those cemented with conventional resin cement.

  11. Processing of continuous fiber composites using thermoplastic polyimide matrix resins

    Energy Technology Data Exchange (ETDEWEB)

    Kranjc, M.D.

    1993-01-01

    Composites have been produced which contain a solvent resistant polyimide matrix with favorable physical properties. The polyimide matrix resin has been designated as P12. The prepegs used to produce the composite contain a low molecular weight resin which is the polyamic acid precursor to P12. Polymerization and imidization of the precursor resin occurs in-situ during processing. Similar commercial systems are often processed in an autoclave and pressure is used at high temperatures to obtain consolidation between prepreg laminates. Pressure is generally applied after polymerization and imidization are complete and at temperatures above the melting point of the polymer. In this research a significant decrease in composite void content was obtained by applying pressure earlier in the cure. Obtaining composites with low void content with these types of systems can be difficult. This is due in part to the generation of low molecular weight reaction by products, water and methanol. High void content results in a decrease in the physical properties of the composite structure. This is especially true for fracture properties. An empirical equation was used to describe the rate of resin removal from the composite to the bleeder cloth during processing. This equation is based on Springer-Loos resin flow model. The conditions in which this model does not apply were also determined. Determining resin removal rates is helpful in producing composites with consistent fiber/resin ratios. In addition, conditions which favor void growth can be prevented.

  12. Clinical evaluation of a flowable resin composite and flowable compomer for preventive resin restorations.

    Science.gov (United States)

    Qin, Man; Liu, HongSheng

    2005-01-01

    This clinical study evaluated the retention and caries protection of a flowable resin composite (Flow Line) and a flowable compomer (Dyract Flow) used in preventive resin restorations as compared to the conventional preventive resin technique which uses a resin composite (Brilliant) and a sealant (Concise). This study observed 205 permanent molars with small carious cavities less than 1.5 mm in width, which were obtained from 165 children aged 7 to 15 years. Flowable resin composite was used to treat 75 teeth, and 71 teeth were treated with flowable compomer in both cavities and caries-free fissures. For the control group, 59 teeth were treated with resin composite in cavities and sealant in caries-free fissures. The teeth were evaluated at 3, 6, 12, 18 and 24-month intervals. After three months, all 205 treated teeth were completely intact. After six months, 66 of the 71 teeth treated with flowable resin composite and 65 of the 70 teeth treated with flowable compomer were complete, compared to 57 of the 58 teeth treated with the conventional preventive resin technique. After 12 months, 60 of the 67 teeth treated with flowable resin composite and 61 of the 67 teeth treated with flowable compomer were complete, compared to 51 of the 55 teeth treated with the conventional preventive resin technique. After 18 months, 53 of the 61 teeth treated with flowable resin composite and 54 of the 62 teeth treated with flowable compomer were complete, compared to 47 of the 53 teeth treated with the conventional preventive resin technique. After 24 months, 49 of the 58 teeth treated with flowable resin composite and 45 of the 57 teeth treated with flowable compomer were complete, compared to 42 of the 52 teeth treated with the conventional preventive resin technique. There were no statistically significant differences in retention rates among all groups after 3, 6, 12, 18 or 24-months (p>0.05). One tooth treated with flowable resin composite and one tooth treated with flowable

  13. Properties of Graphene Oxide/Epoxy Resin Composites

    OpenAIRE

    Jijun Tang; Haijun Zhou; Yunxia Liang; Xinlan Shi; Xin Yang; Jiaoxia Zhang

    2014-01-01

    The graphene oxide (GO) was obtained by pressurized oxidation method using natural graphite as raw materials. Then the GO/epoxy resin composites were prepared by casting. The mechanical and damping properties of composites were studied. As a result, the impact intensity of GO/epoxy resin composites was prominently improved with the content of the graphene oxide increasing. The glass transition temperature decreased and the damping capacity is improved.

  14. Properties of Graphene Oxide/Epoxy Resin Composites

    OpenAIRE

    Jijun Tang; Haijun Zhou; Yunxia Liang; Xinlan Shi; Xin Yang; Jiaoxia Zhang

    2014-01-01

    The graphene oxide (GO) was obtained by pressurized oxidation method using natural graphite as raw materials. Then the GO/epoxy resin composites were prepared by casting. The mechanical and damping properties of composites were studied. As a result, the impact intensity of GO/epoxy resin composites was prominently improved with the content of the graphene oxide increasing. The glass transition temperature decreased and the damping capacity is improved.

  15. Properties of Graphene Oxide/Epoxy Resin Composites

    Directory of Open Access Journals (Sweden)

    Jijun Tang

    2014-01-01

    Full Text Available The graphene oxide (GO was obtained by pressurized oxidation method using natural graphite as raw materials. Then the GO/epoxy resin composites were prepared by casting. The mechanical and damping properties of composites were studied. As a result, the impact intensity of GO/epoxy resin composites was prominently improved with the content of the graphene oxide increasing. The glass transition temperature decreased and the damping capacity is improved.

  16. [Stress profile during curing contraction of composite resin adhesives].

    Science.gov (United States)

    Kunzelmann, K H; Hickel, R

    1990-11-01

    The wall-to-wall curing contraction of thin composite resin layers was recorded with a tensometer. The composite resin was applied to cylindrically shaped ceramic sample holders with diameters of 3 mm, 4 mm and 8 mm. The distances of the sample holders was set at 50 microns, 100 microns, 150 microns, 200 microns and 300 microns. The shrinkage stress recordings clearly show that the shrinkage forces are governed by the distance of the sample holders and not by the volume or the configuration factor of the composite resin layers.

  17. Composite resin: a versatile, multi-purpose restorative material.

    Science.gov (United States)

    Margeas, Robert

    2012-01-01

    Introduced more than some 50 years ago, composite resin technology has simplified the manner in which clinicians practice restorative dentistry, offering greater predictability and improved physical properties. Decades of material science and laboratory development along with clinical trials in human subjects have culminated in composite resin being validated as a reliable, multifunctional restorative material. With a wide range of composite resins available today, clinicians can benefit from knowing the infrastructure of a given material in order to determine which type will work best in a particular clinical situation.

  18. Characterization and Process Development of Cyanate Ester Resin and Composite

    Energy Technology Data Exchange (ETDEWEB)

    Frame, B.J.

    1998-03-01

    Cyanate ester (or polycyanate) resins offer advantages as composite matrices because of their high thermal stability, low outgassing, low water absorption and radiation resistance. This report describes the results of a processing study to develop high-strength hoop-wound composite by the wet-filament winding method using Toray T1000G carbon fiber and YLA RS-14A polycyanate resin as the constituent materials. Process trials, tests and analyses were conducted in order to gain insight into factors that can affect final properties of the cured cyanate ester resin and its composites. The study shows that the cyanate ester resin has a broad process envelope but that an inert-atmosphere cure is essential for obtaining optimum resin and composite properties. Minimizing moisture exposure prior to cure is also crucial as it affects the T{sub g} of the resin and composite. Recommendations for reducing moisture contact with the resin during wet-winding are presented. High fiber volume fraction ({approximately}80%) composites wound and cured with these methods yielded excellent hoop tensile strengths (660 to 670 ksi average with individual rings failing above 700 ksi), which are believed to be the highest recorded strengths for this class of materials. The measured transverse properties were also exceptional for these high fiber fraction composites. Based on the available data, this cyanate ester resin system and its composites are recommended for space and vacuum applications only. Further testing is required before these materials can be recommended for long term use at elevated temperatures in an ambient air environment. The results of all analyses and tests performed as part of this study are presented as well as baseline process for fabricating thick, stage-cured composites. The manufacture of a 1 in. thick composite cylinder made with this process is also described.

  19. Effect of a multi-layer infection control barrier on the micro-hardness of a composite resin

    Directory of Open Access Journals (Sweden)

    In-Nam Hwang

    2012-10-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the effect of multiple layers of an infection control barrier on the micro-hardness of a composite resin. MATERIAL AND METHODS: One, two, four, and eight layers of an infection control barrier were used to cover the light guides of a high-power light emitting diode (LeD light curing unit (LCU and a low-power halogen LCU. The composite specimens were photopolymerized with the LCUs and the barriers, and the micro-hardness of the upper and lower surfaces was measured (n=10. The hardness ratio was calculated by dividing the bottom surface hardness of the experimental groups by the irradiated surface hardness of the control groups. The data was analyzed by two-way ANOVA and Tukey's HSD test. RESULTS: The micro-hardness of the composite specimens photopolymerized with the LED LCU decreased significantly in the four- and eight-layer groups of the upper surface and in the two-, four-, and eight-layer groups of the lower surface. The hardness ratio of the composite specimens was <80% in the eight-layer group. The micro-hardness of the composite specimens photopolymerized with the halogen LCU decreased significantly in the eight-layer group of the upper surface and in the two-, four-, and eight-layer groups of the lower surface. However, the hardness ratios of all the composite specimens photopolymerized with barriers were <80%. CONCLUSIONS: The two-layer infection control barrier could be used on high-power LCUs without decreasing the surface hardness of the composite resin. However, when using an infection control barrier on the low-power LCUs, attention should be paid so as not to sacrifice the polymerization efficiency.

  20. Hardness of resin cement cured under different thickness of lithium disilicate-based ceramic

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuan; WANG Fu

    2011-01-01

    Background The lithium disilicate-based ceramic is a newly developed all-ceramic material,which is lithium disilicate-based and could be used for fabricating almost all kinds of restorations.The extent of light attenuation by ceramic material was material-dependent.Ceramic materials with different crystal composition or crystalline content would exhibit distinct light-absorbing characteristics.The aim of this study was to analyze the influence of ceramic thickness and light-curing time on the polymerization of a dual-curing resin luting material with a lithium disilicate-based ceramic.Methods A lithium disilicate-based ceramic was used in this study.The light attenuation caused by ceramic with different thickness was determined using a spectral radiometer.The commercial dual-cured resin cement was light-cured directly or through ceramic discs with different thickness (1,2 and 3 mm,respectively) for different times (10,20,30,40,50 and 60 seconds,respectively).The polymerization efficiency of resin cement was expressed in terms as Vickers hardness (VHN) measured after 24 hours storage.Two-way analysis of variance (ANOVA) and Tukey's HSD tests were used to determine differences.Results Intensity of polymerizing light transmitted through ceramic discs was reduced from 584 mW/cm2 to about 216 mW/cm2,80 mW/cm2 and 52 mW/cm2 at thicknesses of 1 mm,2 mm and 3 mm,respectively.Resin cement specimens self-cured alone showed significantly lower hardness values.When resin cement was light-cured through ceramic discs with a thickness of 1 mm,2 mm and 3 mm,no further increasing in hardness values was observed when light-curing time was more than 30 seconds,40 seconds and 60 seconds,respectively.Conclusions Within the limitation of the present study,ceramic thickness and light-curing time had remarkable influence on the polymerization of dual-cured resin cement.When resin cement is light-cured beneath a lithium disilicate ceramic with different thickness,prolonging light-curing

  1. 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 Supre

  2. Polimerización de un cemento de composite a través de restauraciones de cerómero utilizando lámparas halógenas y LEDs Polymerization of dual-cure resin luting cements through laboratory-processed-resins: LED versus halogen lights

    Directory of Open Access Journals (Sweden)

    P. Grau Grullón

    2008-08-01

    Full Text Available Este estudio evaluó la influencia del grosor de una restauración indirecta de cerómero, el tipo de lámpara fotoactivadora y el tiempo de almacenamiento en la dureza Vickers de un cemento de composite. Dos lámparas de diodos (Optilight CL [CL] y Ultra-Lume 5 [UL] fueron comparadas con la lámpara halógena (Optilux 401 [OH]. Fueron confeccionados especímenes en cerómero con un diámetro de 5 mm y una espesura de 1 y 2 mm, los cuales fueron interpuestos entre la luz y la matriz metálica de 5 mm de ancho y 0,5 mm de grosor que contenía el cemento de composite. Los 45 cuerpos de prueba fueron divididos en 9 grupos: G1: exposición directa de luz DLE/OH; G2: 1 mm/OH; G3: 2 mm/OH; G4: DLE/CL; G5: 1 mm/CL; G6: 2 mm/CL; G7: DLE/UL; G8: 1 mm/UL y G9: 2 mm/UL. La fotoactivación fue realizada durante 60 segundos. La dureza Vickers (50 g/30s fue medida en la superficie tope de todos los especímenes luego de 24 horas y 180 días de almacenamiento. La lámpara fotoactivadora y el grosor del cerómero fueron estadísticamente significativas (pThis study evaluated the influence of indirect composite resin thickness, the storage time and light-curing units on the Vickers hardness of a dual-cure resin luting cement. Two light-emitting diodes lights (Optilight CL [CL] and UltraLume5 [UL] were compared with a quartz tungsten halogen unit (Optilux 401 [OH]. Laboratory-processed composite specimens with a diameter of 5mm and thickness of 1 and 2 mm were constructed to be interposed between the light guide and the metal matrix (5mm wide and 0.5 mm deep with the resin luting cement. Then, 45 dual-cure resin luting specimens were divided in nine groups: G1: direct light exposure DLE/OH; G2: 1 mm/OH; G3: 2 mm/OH; G4: DLE/CL; G5: 1 mm/CL; G6: 2 mm/CL; G7: DLE/UL; G8: 1 mm/UL and G9: 2 mm/UL. The light curing was performed for 60 seconds. The Vickers hardness (50g/30s was measured at the top surface of all specimens, either after 24 hours or 180 days. The Light-curing

  3. Cytotoxicity evaluation of methacrylate- and silorane-based composite resins

    Directory of Open Access Journals (Sweden)

    Gulsah Goktolga Akin

    2012-10-01

    Full Text Available

    Objectives: The objective of this study was to investigate and compare the cytotoxic effects of four composite resin materials with different content.

    Material and Methods: Two traditional methacrylate-based (Clearfil AP-X, RefleXions, as well as a self-adhering methacrylate-based (Vertise Flow and a silorane-based (Filtek Silorane composite resin were tested in the experiment. Ten cylindrical specimens were made of each material, using a mould (2mm. thick and 8 mm. in diameter. An agar diffusion method was employed, and cytotoxicity rankings were determined using lysis index scores. For statistical analysis, Kruskal-Wallis and Mann-Whitney U-tests were used.

    Results: Amongst the composite resins, the silorane-based composite was found to be less cytotoxic than the methacrylate-based composite resins, which all had the same cytotoxicity ranking.

    Conclusions: The silorane-based composite resin was considered more biocompatible than the methacrylate-based composite resins.

  4. [Influence Factors on Monomer Conversion of Dental Composite Resin].

    Science.gov (United States)

    Wang, Shuang; Gao, Yan; Wang, Jing; Zhang, Yan; Zhang, Yuntao; Wang, Fanghui; Wang, Qingshan

    2015-04-01

    Dental composite resin is a kind of material which has been widely used in dental restoration. Research has found that the influence of residual monomer on the material mechanical, chemical and biological properties cannot be ignored. This paper elaborates these harms of residual monomers. The effects of resin matrix, inorganic filler and initiating system, illumination, secondarily treatment on the degree of conversion were also analyzed. The paper also discusses the effective measures to increase the conversion, and offers theoretical basis for the clinical application and development of composite resin.

  5. Resin-based composites and compomers in primary molars.

    Science.gov (United States)

    García-Godoy, F

    2000-07-01

    Resin-based composite resins and polyacid-modified resin-based composites (compomers) have become popular for the restoration of primary anterior and posterior teeth. In some European countries, resin-based composites or glass-ionomers are the materials of choice for primary teeth because of the controversy over dental amalgam and its alleged adverse health effects resulting from the release of mercury, although a clear correlation between amalgam restorations and health has not been determined. Another reason for the worldwide increased use of resin-based composites and glass-ionomers in pediatric dentistry could be attributed to the growing demand from parents to provide esthetic restorations to their children. More conservative preparations can be performed maintaining more tooth structure because of the adhesive properties of the composites and compomers. The most conservative treatment planning and meticulous care in the placement of the resin-based composites and compomers would produce long-term satisfactory results. These restorations should be placed in patients with low-to-moderate caries risk, and after placement the restorations should be monitored carefully to avoid complications mainly produced by recurrent caries and wear.

  6. Clinical Effectiveness of Different Polishing Systems and Self-Etch Adhesives in Class V Composite Resin Restorations: Two-Year Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Jang, J-H; Kim, H-Y; Shin, S-M; Lee, C-O; Kim, D S; Choi, K-K; Kim, S-Y

    The aim of this randomized controlled clinical trial was to compare the clinical effectiveness of different polishing systems and self-etch adhesives in class V composite resin restorations. A total of 164 noncarious cervical lesions (NCCLs) from 35 patients were randomly allocated to one of four experimental groups, each of which used a combination of polishing systems and adhesives. The two polishing systems used were Sof-Lex XT (Sof), a multistep abrasive disc, and Enhance/Pogo (EP), a simplified abrasive-impregnated rubber instrument. The adhesive systems were Clearfil SE bond (CS), a two-step self-etch adhesive, and Xeno V (XE), a one-step self-etch adhesive. All NCCLs were restored with light-cured microhybrid resin composites (Z250). Restorations were evaluated at baseline and at 6, 12, 18, and 24 months by two blinded independent examiners using modified FDI criteria. The Fisher exact test and generalized estimating equation analysis considering repeated measurements were performed to compare the outcomes between the polishing systems and adhesives. Three restorations were dislodged: two in CS/Sof and one in CS/EP. None of the restorations required any repair or retreatment except those showing retention loss. Sof was superior to EP with regard to surface luster, staining, and marginal adaptation (p0.05). Sof is clinically superior to EP for polishing performance in class V composite resin restoration. XE demonstrates clinically equivalent bonding performance to CS.

  7. Surface modification with alumina blasting and H2SO4-HCl etching for bonding two resin-composite veneers to titanium.

    Science.gov (United States)

    Taira, Yohsuke; Egoshi, Takafumi; Kamada, Kohji; Sawase, Takashi

    2014-02-01

    The purpose of this study was to investigate the effect of an experimental surface treatment with alumina blasting and acid etching on the bond strengths between each of two resin composites and commercially pure titanium. The titanium surface was blasted with alumina and then etched with 45wt% H2SO4 and 15wt% HCl (H2SO4-HCl). A light- and heat-curing resin composite (Estenia) and a light-curing resin composite (Ceramage) were used with adjunctive metal primers. Veneered specimens were subjected to thermal cycling between 4 and 60°C for 50,000 cycles, and the shear bond strengths were determined. The highest bond strengths were obtained for Blasting/H2SO4-HCl/Estenia (30.2 ± 4.5 MPa) and Blasting/Etching/Ceramage (26.0 ± 4.5 MPa), the values of which were not statistically different, followed by Blasting/No etching/Estenia (20.4 ± 2.4 MPa) and Blasting/No etching/Ceramage (0.8 ± 0.3 MPa). Scanning electron microscopy observations revealed that alumina blasting and H2SO4-HCl etching creates a number of micro- and nanoscale cavities on the titanium surface, which contribute to adhesive bonding.

  8. Influence of the curing method on the post-polymerization shrinkage stress of a composite resin

    Directory of Open Access Journals (Sweden)

    Leonardo Gonçalves Cunha

    2008-08-01

    Full Text Available The aim of this study was to evaluate the effect of different curing methods on the stress generated by the polymerization shrinkage of a restorative composite in two moments: immediately after light exposure and after 5 min. Photoactivation was performed using two different light sources: (1 xenon plasma arc (PAC light (1,500 mW/cm2 - 3s and (2 a quartz-tungsten-halogen (QTH light with three light-curing regimens: continuous exposure (40 s at 800 mW/cm2 - CL; soft-start (10 s at 150 mW/cm2 and 30 s at 800 mW/cm2 - SS and intermittent light [cycles of 4 s (2 s with light on at 600 mW/cm2 and 2 s of light off, for 80s - IL]. The composite resin was applied between two 5-mm diameter metallic rods, mounted in a servohydraulic machine. The maximum stress was recorded immediately after light exposure (FF and after 5 min (5F. The results were submitted to ANOVA and Tukey's test (5%. For each method, the results obtained in FF and 5F were, respectively: CL (3.58 and 4.46 MPa; SS (2.99 and 4.36 MPa; IL (3.11 and 4.32 MPa and PAC (0.72 and 3.27 MPa. The stress generated by the polymerization shrinkage during light exposure can be associated with the photoactivation method used. A significant increase in the stress level was observed during the post-curing period up to 5 min, for all evaluated methods.

  9. Direct composite resin layering techniques for creating lifelike CAD/CAM-fabricated composite resin veneers and crowns.

    Science.gov (United States)

    LeSage, Brian

    2014-07-01

    Direct composite resin layering techniques preserve sound tooth structure and improve function and esthetics. However, intraoral placement techniques present challenges involving isolation, contamination, individual patient characteristics, and the predictability of restorative outcomes. Computer-aided design and computer-aided manufacturing (CAD/CAM) restorations enable dentists to better handle these variables and provide durable restorations in an efficient and timely manner; however, milled restorations may appear monochromatic and lack proper esthetic characteristics. For these reasons, an uncomplicated composite resin layering restoration technique can be used to combine the benefits of minimally invasive direct restorations and the ease and precision of indirect CAD/CAM restorations. Because most dentists are familiar with and skilled at composite resin layering, the use of such a technique can provide predictable and highly esthetic results. This article describes the layered composite resin restoration technique.

  10. Effect of ultraviolet light irradiation on bonding of experimental composite resin artificial teeth.

    Science.gov (United States)

    Loyaga-Rendon, Paola G; Takahashi, Hidekazu; Iwasaki, Naohiko; Reza, Fazal

    2007-11-01

    The purpose of the present study was to evaluate how ultraviolet light (UV) irradiation using an ordinary UV sterilizer would affect the bonding of experimental composite resins to an autopolymerizing acrylic resin. To this end, three composite resins and one unfilled resin--of which the compositions were similar to commercial composite resin artificial teeth--were prepared as repair composites. Their shear bond strengths after UV irradiation for one to 60 minutes were significantly greater than those before UV irradiation regardless of composite resin type. Failure mode after UV irradiation for one to 60 minutes was mainly cohesive failure of the composite resins, but that before UV irradiation and after 24 hours' irradiation was mainly adhesive failure. These results thus suggested that a short period of UV irradiation on composite resin teeth would improve the bonding efficacy of composite resin artificial teeth to autopolymerizing resin.

  11. 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,

  12. 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, U

  13. PENYINARAN BERLEBIHAN PADA TAMBALAN RESIN KOMPOSIT DAN AKIBAT YANG DITIMBULKAN

    Directory of Open Access Journals (Sweden)

    Venita Tanusuwito

    2015-07-01

    Full Text Available Dentists are often taught that 'overcure' is better than ' undercure'. Undercure is said to cause serious problem with resin composite fillings. Actually it does not always happen this way. Overcure also has several bad impacts that have never been thought before by practitioners. Researchers claim that curing time informed by resin composite manufacturers is not always correct. Filling material is not the only factor that determines the correct curing time for each filling. Light cure unit performance also plays a major role.

  14. Microtensile bond strength of repaired indirect resin composite.

    Science.gov (United States)

    Visuttiwattanakorn, Porntida; Suputtamongkol, Kallaya; Angkoonsit, Duangjai; Kaewthong, Sunattha; Charoonanan, Piyanan

    2017-02-01

    The objective of this study was to investigate the effect of surface treatments on microtensile bond strengths (MTBSs) of two types of indirect resin composites bonded to a conventional direct resin composite. Indirect resin composite blocks of Ceramage and SR Nexco were prepared in a plastic mold having a dimension of 10 × 10 × 4 mm. These composite blocks were divided into three groups according to their surface treatments: Group1: Sandblast (SB); Group2: Sandblast and ultrasonically clean (SB+UL); Group3: Sandblast plus silane (SB+SI). After bonding with direct resin composite, indirect-direct resin composite blocks were kept in distilled water for 24 hours at 37℃ and cut into microbars with the dimension of 1 × 1 × 8 mm. Microbar specimens (n = 40 per group) were loaded using a universal testing machine. Failure modes and compositions were evaluated by SEM. The statistical analyses of MTBS were performed by two-way ANOVA and Dunnett's test at α = .05. Surface treatments and brands had effects on the MTBS without an interaction between these two factors. For SR Nexco, the MTBSs of SB and SB+SI group were significantly higher than that of SB+UL. For Ceramage, the MTBSs of SB and SB+SI were significantly higher than that of SB+UL. The mean MTBS of the Ceramage specimens was significantly higher than that of SR Nexco for all surface treatments. Sandblasting with or without silane application could improve the bond strengths of repaired indirect resin composites to a conventional direct resin composite.

  15. Microtensile bond strength of repaired indirect resin composite

    Science.gov (United States)

    Suputtamongkol, Kallaya; Angkoonsit, Duangjai; Kaewthong, Sunattha; Charoonanan, Piyanan

    2017-01-01

    PURPOSE The objective of this study was to investigate the effect of surface treatments on microtensile bond strengths (MTBSs) of two types of indirect resin composites bonded to a conventional direct resin composite. MATERIALS AND METHODS Indirect resin composite blocks of Ceramage and SR Nexco were prepared in a plastic mold having a dimension of 10 × 10 × 4 mm. These composite blocks were divided into three groups according to their surface treatments: Group1: Sandblast (SB); Group2: Sandblast and ultrasonically clean (SB+UL); Group3: Sandblast plus silane (SB+SI). After bonding with direct resin composite, indirect-direct resin composite blocks were kept in distilled water for 24 hours at 37℃ and cut into microbars with the dimension of 1 × 1 × 8 mm. Microbar specimens (n = 40 per group) were loaded using a universal testing machine. Failure modes and compositions were evaluated by SEM. The statistical analyses of MTBS were performed by two-way ANOVA and Dunnett's test at α = .05. RESULTS Surface treatments and brands had effects on the MTBS without an interaction between these two factors. For SR Nexco, the MTBSs of SB and SB+SI group were significantly higher than that of SB+UL. For Ceramage, the MTBSs of SB and SB+SI were significantly higher than that of SB+UL. The mean MTBS of the Ceramage specimens was significantly higher than that of SR Nexco for all surface treatments. CONCLUSION Sandblasting with or without silane application could improve the bond strengths of repaired indirect resin composites to a conventional direct resin composite. PMID:28243390

  16. A temporary space maintainer using acrylic resin teeth and a composite resin.

    Science.gov (United States)

    Kochavi, D; Stern, N; Grajower, R

    1977-05-01

    A one-session technique for preparing a temporary space maintainer has been described. The technique consists of attaching an acrylic resin pontic to etched surfaces of natural adjacent teeth by means of a composite resin. The main advantages of this technique are elimination of premature tooth preparation, good esthetics, fair strength, low cost, and rapid completion of the restoration without the need of a dental laboratory.

  17. Effect of configuration factor on gap formation in hybrid composite resin, low-shrinkage composite resin and resin-modified glass ionomer.

    Science.gov (United States)

    Boroujeni, Parvin M; Mousavinasab, Sayyed M; Hasanli, Elham

    2015-05-01

    Polymerization shrinkage is one of the important factors in creation of gap between dental structure and composite resin restorations. The aim of this study was to evaluate the effect of configuration factor (C-factor) on gap formation in a hybrid composite resin, a low shrinkage composite resin and a resin modified glass ionomer restorative material. Cylindrical dentin cavities with 5.0 mm diameter and three different depths (1.0, 2.0 and 3.0 mm) were prepared on the occlusal surface of 99 human molars and the cavities assigned into three groups (each of 33). Each group contained three subgroups depend on the different depths and then cavities restored using resin modified glass ionomer (Fuji II LC Improved) and two type composite resins (Filtek P90 and Filtek Z250). Then the restorations were cut into two sections in a mesiodistal direction in the middle of restorations. Gaps were measured on mesial, distal and pulpal floor of the cavities, using a stereomicroscope. Data analyses using Kruskal-Wallist and Mann-Whitney tests. Increasing C-factor from 1.8 to 3.4 had no effect on the gap formation in two type composite resins, but Fuji II LC Improved showed significant effect of increasing C-factor on gap formation. Taken together, when C-factor increased from 1.8 up to 3.4 had no significant effect on gap formation in two tested resin composites. Although, Filtek P90 restorations showed smaller gap formation in cavities walls compared to Filtek Z250 restorations. High C-factor values generated the largest gap formation. Silorane-based composite was more efficient for cavity sealing than methacrylate-based composites and resin modified glass ionomer. © 2014 Wiley Publishing Asia Pty Ltd.

  18. Timing for composite resin placement on mineral trioxide aggregate.

    Science.gov (United States)

    Tsujimoto, Masaki; Tsujimoto, Yasuhisa; Ookubo, Atsushi; Shiraishi, Takanobu; Watanabe, Ikuya; Yamada, Shizuka; Hayashi, Yoshihiko

    2013-09-01

    The aim of this study was to investigate the proper time to restore composite resin over mineral trioxide aggregate (MTA). Thirty-five samples of MTA blocks were divided into 7 groups with 3 different times (10 minutes, 1 day, and 7 days) selected for restoring the composite resin over MTA with and without bonding resin, and a control group was included for comparison. After 21 days, the distances between MTA and the composite resin or between MTA and the bonding agent on sectioned planes along the long axis were measured using a scanning electron microscope (×2,000 magnification). The hardness of the MTA near the composite resin was presented as the Vickers microhardness. There were no gaps at the interface in the 10-minute groups, the 1-day group with a bonding agent, and the 7-day group with a bonding agent. The groups without a bonding agent at 1 and 7 days presented a separation or gap at the interface. The value of the Vickers microhardness in the 1-day groups was significantly decreased compared with those of the other groups regardless of the presence or absence of a bonding agent. These findings suggest that composite resin with a bonding agent over MTA can be restored almost immediately after MTA mixing during a single visit. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. 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.

  20. Effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin

    Directory of Open Access Journals (Sweden)

    Marjaneh Ghavamnasiri

    2015-01-01

    Full Text Available Objectives: To evaluate the effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin. Materials and Methods: One hundred and sixty-one Class I cavities were prepared on extracted premolars and divided into seven groups. Group 1: Light-cured composite; Groups 2, 3, and 4: Amalgam stored in 37°C normal saline for respectively 1, 3, and 6 months and then replaced with composite leaving the cavity walls intact. Groups 5, 6, and 7: Identical to Groups 2, 3, and 4, except the cavity walls were extended 0.5 mm after amalgam removal. Eighteen specimens from each group were selected for shear bond strength testing, while on remaining five samples, elemental microanalysis was conducted. Data were analyzed using Mann-Whitney and Freidman (α = 0.05. Results: There was a significant difference between Groups 1 and 4 and also between Group 1 and Groups 5, 6, and 7. However, Groups 1, 2, and 3 showed no significant difference regarding bond strength. Bond strengths of Group 4 was significantly less than Groups 2 and 3. However, Groups 5, 6, and 7 showed similar bond strength. There was no difference among all groups in terms of metal elements at any storage times.

  1. 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.......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....

  2. Estudo laboratorial de teste de resistência ao tracionamento da resina composta fotopolimerizável Fill Magic® destinada à colagem de braquetes para tracionamento ortodôntico de dentes retidos Laboratorial study to test traction resistance of Fill Magic® light-cured resin intended for orthodontic traction of unerupted teeth

    Directory of Open Access Journals (Sweden)

    Felipe Ladeira Pereira

    2006-02-01

    Full Text Available OBJETIVO: Avaliar a resistência à tração de duas resinas utilizadas para colagem de acessórios para tracionamento dentário. METODOLOGIA: o presente estudo comparou a adesividade e praticidade de duas resinas destinadas ao tracionamento ortodôntico de dentes impactados: a Concise® da 3M®, presente no mercado há alguns anos e tida como referência na realização deste procedimento; e a Fill Magic® da Vigodent®, cuja técnica é julgada mais simples pelo fabricante. Foram incluídos 40 terceiros molares em corpos de prova e estes divididos em dois grupos de 20, um para cada resina. Uma vez colados os braquetes, os corpos de prova foram submetidos à força de tração horizontal (10 de cada grupo e vertical (10 de cada grupo, até que os braquetes se soltassem. Os valores obtidos na máquina universal de ensaios foram registrados e comparados por meio de médias para que fosse possível estabelecer as vantagens e desvantagens de cada resina. RESULTADO E CONCLUSÃO: apesar dos valores obtidos com a resina Fill Magic® terem sido menores que os da resina Concise®, comprovou-se que eles são suficientes para a realização do tracionamento ortodôntico.AIM: comparisson of two composite adhesives used for orthodontic traction procedures. METHODS: this article compared the bonding capability and practice of two resins for direct orthodontic traction: the 3M®'s Concise®, been sold in the market for a few years and the reference for this kind of procedure; and Vigodent®'s Fill Magic®, which technique is much simpler according to the manufacturer. Forty third molars were included into acrylic resin and divided in two groups of 20, one for each resin. Once the brackets were bonded, the specimens were submitted to horizontal force (10 of each group and vertical (10 of each group, till the bracket got lost. The score obtained in the universal testing machine were recorded and compared by the average to set the advantages and disadvantages of

  3. 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.

  4. Three-year clinical evaluation of a silorane composite resin.

    Science.gov (United States)

    Walter, Ricardo; Boushell, Lee W; Heymann, Harald O; Ritter, Andre V; Sturdevant, John R; Wilder, Aldridge D; Chung, Yunro; Swift, Edward J

    2014-01-01

    Composite resins are still outperformed by amalgams in the clinical practice with secondary caries and fractures being their most common failures. A material that suffers less polymerization shrinkage might improve the clinical performance of composite resins. To evaluate the clinical performance of a low-shrink silorane-based composite resin (Filtek LS Low Shrink Posterior Restorative, 3M ESPE, St. Paul, MN, USA) in comparison with a methacrylate-based composite resin (Tetric EvoCeram, Ivoclar Vivadent, Schaan, Principality of Liechtenstein) over time. Candidates in need of Class II composite resin restorations participated in this randomized controlled clinical trial. Those were 25 female and six male subjects with average age of 44.3 ± 12.7 years. Participants received 82 restorations, being 54 in premolars and 28 in molars. Procedures, which included the restoration of primary caries lesions or replacement of failing restorations, were done using modified preparations with no bevels or additional retention. Restorations were placed using Filtek LS (and dedicated self-etch adhesive) or Tetric EvoCeram (with AdheSE, Ivoclar Vivadent), following manufacturers' instructions. Incremental placement technique was applied and the restorations were immediately finished. Follow-up evaluations occurred at six, 12, 24, and 36 months and were done using the Fédération Dentaire Internationale criteria. Statistical analysis was performed using generalized estimating equations. The recall rate at 36 months was 89%. All interaction terms were not significant. Filtek LS performs as well as Tetric EvoCeram performs in the clinical setting at 36 months. The silorane-based composite resin Filtek LS and the conventional methacrylate-based composite resin Tetric EvoCeram performed similarly well in posterior restorations over at least 36 months of clinical service. © 2013 Wiley Periodicals, Inc.

  5. Immediate vs delayed repair bond strength of a nanohybrid resin composite.

    Science.gov (United States)

    El-Askary, Farid S; El-Banna, Ahmed H; van Noort, Richard

    2012-06-01

    To evaluate both the immediate and water-stored repair tensile bond strength (TBS) of a nanohybrid resin composite using different bonding protocols. One hundred sixty half hourglass-shaped slabs were prepared. Eighty half-slabs were wet ground immediately after light curing using high-speed abrasive burs, while the other half-slabs were stored in water for one month (delayed) and then wet ground for repair. Each set of the 80 repaired slabs was split into two groups to be tested for TBS after 24 h or 1 month of water storage. For all repaired slabs, either immediate or delayed, four bonding procedures were used involving wet and dry bonding with a 3-step etch-and-rinse adhesive with or without silane pretreatment. TBS tests were performed at a crosshead speed of 0.5 mm/min. To determine the cohesive strength of the resin composite itself, which served as the reference, additional whole slabs were prepared and tested in tension after a 24-h (n = 10) and a 1-month storage period (n = 10). Failure modes were evaluated using a stereomicroscope at 40X magnification. Three-way ANOVA was run to test the effect of water storage, testing time, bonding protocols, and their interactions on the repair TBS, which was given as a percentage of the reference values. For the immediate repair groups, the repair TBS ranged from 40% to 61.9% after 24-h storage and from 26% to 53.1% after 1-month water storage compared to the TBS of the whole slabs. For the delayed repair group, the repaired TBS ranged from 47.2% to 63.6% for the 24-h repairs and from 32.2% to 44.2% for the test groups stored in water for 1 month. Three-way ANOVA revealed that water storage had no significant effect on the repair TBS (p = 0.619). Both testing time and bonding protocols had a significant effect on the repair TBS (p = 0.001). The interactions between the independent variables (water storage, testing time, and bonding protocols) had no significant effect (p = 0.067). The repair bond strength was

  6. Characterization and Process Development of Cyanate Ester Resin Composites

    Energy Technology Data Exchange (ETDEWEB)

    Frame, B.J.

    1999-05-23

    Cyanate ester resins offer advantages as composite matrices because of their high thermal stability, low outgassing, low water absorption, and radiation resistance. This paper describes the results of a processing study to develop a high-strength hoop-wound composite by the wet-filament winding method using Toray TI 000G carbon fiber and YLA RS- 14A cyanate ester resin as the constituent materials. The study shows that the cyanate ester resin has a broad process envelope but that an inert-atmosphere cure is essential for obtaining optimum resin and composite properties. Minimizing moisture exposure prior to and during cure is also crucial as it affects the glass transition temperature of the resin and composite. Composite cylinders wound and cured with these methods yielded excellent ring tensile strengths both at room and elevated temperature. A summary of the measured mechanical and thermal property data for these composites is presented. Potential applications for these materials include flywheeI energy storage systems for space and satellite structures.

  7. 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)

  8. Degradation, Fatigue, and Failure of Resin Dental Composite Materials

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, J.L. (UIC)

    2008-11-03

    The intent of this article is to review the numerous factors that affect the mechanical properties of particle- or fiber-filler-containing indirect dental resin composite materials. The focus will be on the effects of degradation due to aging in different media, mainly water and water and ethanol, cyclic loading, and mixed-mode loading on flexure strength and fracture toughness. Several selected papers will be examined in detail with respect to mixed and cyclic loading, and 3D tomography with multi-axial compression specimens. The main cause of failure, for most dental resin composites, is the breakdown of the resin matrix and/or the interface between the filler and the resin matrix. In clinical studies, it appears that failure in the first 5 years is a restoration issue (technique or material selection); after that time period, failure most often results from secondary decay.

  9. Degradation, fatigue, and failure of resin dental composite materials.

    Science.gov (United States)

    Drummond, J L

    2008-08-01

    The intent of this article is to review the numerous factors that affect the mechanical properties of particle- or fiber-filler-containing indirect dental resin composite materials. The focus will be on the effects of degradation due to aging in different media, mainly water and water and ethanol, cyclic loading, and mixed-mode loading on flexure strength and fracture toughness. Several selected papers will be examined in detail with respect to mixed and cyclic loading, and 3D tomography with multi-axial compression specimens. The main cause of failure, for most dental resin composites, is the breakdown of the resin matrix and/or the interface between the filler and the resin matrix. In clinical studies, it appears that failure in the first 5 years is a restoration issue (technique or material selection); after that time period, failure most often results from secondary decay.

  10. High elastic modulus nanopowder reinforced resin composites for dental applications

    Science.gov (United States)

    Wang, Yijun

    2007-12-01

    Dental restorations account for more than $3 billion dollars a year on the market. Among them, all-ceramic dental crowns draw more and more attention and their popularity has risen because of their superior aesthetics and biocompatibility. However, their relatively high failure rate and labor-intensive fabrication procedure still limit their application. In this thesis, a new family of high elastic modulus nanopowder reinforced resin composites and their mechanical properties are studied. Materials with higher elastic modulus, such as alumina and diamond, are used to replace the routine filler material, silica, in dental resin composites to achieve the desired properties. This class of composites is developed to serve (1) as a high stiffness support to all-ceramic crowns and (2) as a means of joining independently fabricated crown core and veneer layers. Most of the work focuses on nano-sized Al2O3 (average particle size 47 nm) reinforcement in a polymeric matrix with 50:50 Bisphenol A glycidyl methacrylate (Bis-GMA): triethylene glycol dimethacrylate (TEGDMA) monomers. Surfactants, silanizing agents and primers are examined to obtain higher filler levels and enhance the bonding between filler and matrix. Silane agents work best. The elastic modulus of a 57.5 vol% alumina/resin composite is 31.5 GPa compared to current commercial resin composites with elastic modulus alumina, diamond/resin composites are studied. An elastic modulus of about 45 GPa is obtained for a 57 vol% diamond/resin composite. Our results indicate that with a generally monodispersed nano-sized high modulus filler, relatively high elastic modulus resin-based composite cements are possible. Time-dependent behavior of our resin composites is also investigated. This is valuable for understanding the behavior of our material and possible fatigue testing in the future. Our results indicate that with effective coupling agents and higher filler loading, viscous flow can be greatly decreased due to the

  11. Postoperative sensitivity in class I composite resin restorations in vivo

    OpenAIRE

    Casselli, DSM; Martins, LRM

    2006-01-01

    Purpose: This study evaluated the postoperative sensitivity of posterior Class I composite resin restorations, restored with a self-etching or a total-etch one-bottle adhesive system. Materials and Methods: One hundred four restorations were replaced by one clinician in 52 patients. Each patient received two restorations. After cavity preparations were completed under rubber-dam isolation, they were restored using Clearfil SE Bond or Single Bond and a resin-based restorative material (Filtek ...

  12. Development of strong and bioactive calcium phosphate cement as a light-cure organic-inorganic hybrid.

    Science.gov (United States)

    Barounian, M; Hesaraki, S; Kazemzadeh, A

    2012-07-01

    In this research, light cured calcium phosphate cements (LCCPCs) were developed by mixing a powder phase (P) consisting of tetracalcium phosphate and dicalcium phosphate and a photo-curable resin phase (L), mixture of hydroxyethylmethacrylate (HEMA)/poly acrylic-maleic acid at various P/L ratios of 2.0, 2.4 and 2.8 g/mL. Mechanical strength, phase composition, chemical groups and microstructure of the cured cements were evaluated at pre-set times, i.e. before and after soaking in simulated body fluid (SBF). The proliferation of Rat-derived osteoblastic cells onto the LCCPCs as well as cytotoxicity of cement extracts were determined by cell counting and 3-{4,5-dimethylthiazol-2yl}-2,5-diphenyl-2H-tetrazolium bromide assay after different culture times. It was estimated from Fourier transforming infrared spectra of cured cements that the setting process is ruled by polymerization of HEMA monomers as well as formation of calcium poly-carboxylate salts. Microstructure of the cured cements consisted of calcium phosphate particles surrounded by polymerized resin phase. Formation of nano-sized needlelike calcium phosphate phase on surfaces of cements with P/L ratios of 2.4 and 2.8 g/mL was confirmed by scanning electron microscope images and X-ray diffractometry (XRD) of the cured specimen soaked in SBF for 21 days. Also, XRD patterns revealed that the formed calcium phosphate layer was apatite phase in a poor crystalline form. Biodegradation of the cements was confirmed by weight loss, change in molecular weight of polymer and morphology of the samples after different soaking periods. The maximum compressive strength of LCCPCs governed by resin polymerization and calcium polycarboxylate salts formation was about 80 MPa for cement with P/L ratio of 2.8 g/mL, after incubation for 24 h. The strength of all cements decreased by decreasing P/L ratio as well as increasing soaking time. The preliminary cell studies revealed that LCCPCs could support proliferation of

  13. Preparation and properties of lignin-epoxy resin composite

    Directory of Open Access Journals (Sweden)

    Quanfu Yin

    2012-11-01

    Full Text Available A cross-linked biomass-polymer composite with a lignin content of up to 60% was prepared by blending lignin with an epoxy resin and polyamine using a hot press molding process. The characteristics of the curing reaction of lignin with epoxy resin were studied using DSC and FTIR analysis. The effect of molding temperature and molding pressure on the mechanical properties and microstructure of the lignin/epoxy resin composite was also studied by SEM, DMA, and TG analyses. The results showed that the epoxy resin can be cured by lignin, and the curing temperature for the blends can be reduced by the introduction of a polyamine cure agent. The properties of the composite, such as bending strength, impact strength, glass-transition temperature, and thermal stability, were evidently influenced by the molding process. A good interfacial combination was formed between lignin and epoxy resin. Increasing the molding temperature and pressure proved beneficial to achieve a better interfacial combination for the composite, and the degree of ductile fracture was increased in the fracture surface of the composite.

  14. One year comparative clinical evaluation of EQUIA with resin-modified glass ionomer and a nanohybrid composite in noncarious cervical lesions

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    Deepa Sunil Vaid

    2015-01-01

    Full Text Available Aims: Comparative evaluation of EQUIA with a resin-modified glass ionomer cement (RMGIC; GC Gold Label glass ionomer light cured universal restorative cement and a nanohybrid composite (Tetric N-Ceram in noncarious cervical lesions (NCCLs. Background: To establish the most suitable material for the restoration of NCCLs. Settings and Design: In vivo study. Materials and Methods: Eighty-seven NCCLs were randomly restored with EQUIA, a RMGIC, and a nanohybrid composite. Clinical evaluation of the restorations was done following the Unites States Public Health criteria by a single-blinded investigator. Data were formulated, and statistical analysis was done by Chi-square test. Statistical Analysis Used: Chi-square test. Results: No significant difference was found between EQUIA, RMGIC, and nanohybrid composite at 1-month, at 6 months, and at 1-year (P > 0.05. Conclusions: EQUIA, resin-modified glass ionomer, and nanohybrid composite performed equally at 1-month, 6 months, and 1-year follow-up periods.

  15. Properties of hybrid resin composite systems containing prepolymerized filler particles.

    Science.gov (United States)

    Blackham, Jason T; Vandewalle, Kraig S; Lien, Wen

    2009-01-01

    This study compared the properties of newer hybrid resin composites with prepolymerized-filler particles to traditional hybrids and a microfill composite. The following properties were examined per composite: diametral tensile strength, flexural strength/modulus, Knoop microhardness and polymerization shrinkage. Physical properties were determined for each Jason T Blackham, DMD, USAF, General Dentistry, Tyndall composite group (n = 8), showing significant differences between groups per property (p hybrid composites (Z250, Esthet-X) had higher strength, composites containing pre-polymerized fillers (Gradia Direct Posterior, Premise) performed more moderately and the microfill composite (Durafill VS) had lower strength. Premise and Durafill VS had the lowest polymerization shrinkage.

  16. Effect of preheating of low shrinking resin composite on intrapulpal temperature and microtensile bond strength to dentin

    Science.gov (United States)

    El-Deeb, Heba A.; Abd El-Aziz, Sara; Mobarak, Enas H.

    2014-01-01

    The effect of preheating of the silorane-based resin composite on intrapulpal temperature (IPT) and dentin microtensile bond strength (μTBS) was evaluated. For the IPT, teeth (n = 15) were sectioned to obtain discs of 0.5 mm thickness (2 discs/tooth). The discs were divided into three groups (n = 10/group) according to the temperature of the Filtek LS™ silorane-based resin composite during its placement, either at room temperature (23 ± 1 °C) or preheated to 54 °C or 68 °C using a commercial Calset™ device. Discs were subjected to a simulated intrapulpal pressure (IPP) and placed inside a specially constructed incubator adjusted at 37 °C. IPT was measured before, during and after placement and curing of the resin composite using K-type thermocouple. For μTBS testing, flat occlusal middentin surfaces (n = 24) were obtained. P90 System Adhesive was applied according to manufacturer’s instructions then Filtek LS was placed at the tested temperatures (n = 6). Restorative procedures were done while the specimens were connected to IPP simulation. IPP was maintained and the specimens were immersed in artificial saliva at 37 °C for 24 h before testing. Each specimen was sectioned into sticks (0.9 ± 0.01 mm2). The sticks (24/group) were subjected to μTBS test and their modes of failure were determined using scanning electron microscope (SEM). For both preheated groups, IPT increased equally by 1.5–2 °C upon application of the composite. After light curing, IPT increased by 4–5 °C in all tested groups. Nevertheless, the IPT of the preheated groups required a longer time to return to the baseline temperature. One-way ANOVA revealed no significant difference between the μTBS values of all groups. SEM revealed predominately mixed mode of failure. Preheating of silorane-based resin composite increased the IPT but not to the critical level and had no effect on dentin μTBS. PMID:26257945

  17. Effect of preheating of low shrinking resin composite on intrapulpal temperature and microtensile bond strength to dent

    Directory of Open Access Journals (Sweden)

    Heba A. El-Deeb

    2015-05-01

    Full Text Available The effect of preheating of the silorane-based resin composite on intrapulpal temperature (IPT and dentin microtensile bond strength (μTBS was evaluated. For the IPT, teeth (n = 15 were sectioned to obtain discs of 0.5 mm thickness (2 discs/tooth. The discs were divided into three groups (n = 10/group according to the temperature of the Filtek LS™ silorane-based resin composite during its placement, either at room temperature (23 ± 1 °C or preheated to 54 °C or 68 °C using a commercial Calset™ device. Discs were subjected to a simulated intrapulpal pressure (IPP and placed inside a specially constructed incubator adjusted at 37 °C. IPT was measured before, during and after placement and curing of the resin composite using K-type thermocouple. For μTBS testing, flat occlusal middentin surfaces (n = 24 were obtained. P90 System Adhesive was applied according to manufacturer’s instructions then Filtek LS was placed at the tested temperatures (n = 6. Restorative procedures were done while the specimens were connected to IPP simulation. IPP was maintained and the specimens were immersed in artificial saliva at 37 °C for 24 h before testing. Each specimen was sectioned into sticks (0.9 ± 0.01 mm2. The sticks (24/group were subjected to μTBS test and their modes of failure were determined using scanning electron microscope (SEM. For both preheated groups, IPT increased equally by 1.5–2 °C upon application of the composite. After light curing, IPT increased by 4–5 °C in all tested groups. Nevertheless, the IPT of the preheated groups required a longer time to return to the baseline temperature. One-way ANOVA revealed no significant difference between the μTBS values of all groups. SEM revealed predominately mixed mode of failure. Preheating of silorane-based resin composite increased the IPT but not to the critical level and had no effect on dentin μTBS.

  18. Effect of preheating of low shrinking resin composite on intrapulpal temperature and microtensile bond strength to dentin.

    Science.gov (United States)

    El-Deeb, Heba A; Abd El-Aziz, Sara; Mobarak, Enas H

    2015-05-01

    The effect of preheating of the silorane-based resin composite on intrapulpal temperature (IPT) and dentin microtensile bond strength (μTBS) was evaluated. For the IPT, teeth (n = 15) were sectioned to obtain discs of 0.5 mm thickness (2 discs/tooth). The discs were divided into three groups (n = 10/group) according to the temperature of the Filtek LS™ silorane-based resin composite during its placement, either at room temperature (23 ± 1 °C) or preheated to 54 °C or 68 °C using a commercial Calset™ device. Discs were subjected to a simulated intrapulpal pressure (IPP) and placed inside a specially constructed incubator adjusted at 37 °C. IPT was measured before, during and after placement and curing of the resin composite using K-type thermocouple. For μTBS testing, flat occlusal middentin surfaces (n = 24) were obtained. P90 System Adhesive was applied according to manufacturer's instructions then Filtek LS was placed at the tested temperatures (n = 6). Restorative procedures were done while the specimens were connected to IPP simulation. IPP was maintained and the specimens were immersed in artificial saliva at 37 °C for 24 h before testing. Each specimen was sectioned into sticks (0.9 ± 0.01 mm(2)). The sticks (24/group) were subjected to μTBS test and their modes of failure were determined using scanning electron microscope (SEM). For both preheated groups, IPT increased equally by 1.5-2 °C upon application of the composite. After light curing, IPT increased by 4-5 °C in all tested groups. Nevertheless, the IPT of the preheated groups required a longer time to return to the baseline temperature. One-way ANOVA revealed no significant difference between the μTBS values of all groups. SEM revealed predominately mixed mode of failure. Preheating of silorane-based resin composite increased the IPT but not to the critical level and had no effect on dentin μTBS.

  19. The effect of flowable and dual-cure resin composite liners on gingival microleakage of posterior resin composites

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    Shirani F.

    2008-11-01

    Full Text Available "nBackground and Aim: Microleakage has been always a major concern in restorative dentistry. The curing contraction of composites still presents a problem with controlling microleakage and postoperative sensitivity. The aim of this study was to investigate the effect of flowable and dual-cure resin composite liners on gingival microleakage of packable resin composite restorations. "nMaterials and Methods: Sixty Class II cavities with cervical margins 1 mm below the CEJ were prepared in 30 extracted human molars. The teeth were randomly divided into five groups of 12 each. In control group, each tooth was restored incrementally with Tetric Ceram composite without applying any liner. In the second and forth groups, flowable materials- Tetric Flow and dual-cure composite resin cement Relay X ARC were placed respectively as a 1-mm thick gingival increment and cured before the resin composite restoration, whereas, in the third and fifth groups liners were cured with the first increment of packable composite.The restored teeth were stored for one week in distilled water at 370C, and thermocycled between 50C and 550C, sealed with nail varnish except the tooth - composite interface in cervical restoration margins and immersed in 2% basic fuchsin for 24 hours. Dye penetration was evaluated using a stereomicroscope with 28x magnification. The data were analyzed by Kruskal-Wallis and Mann-Whitney U-tests with p<0.05 as the level of significance. "nResults: The results of this study indicated that there were significant statistical differences between control - cured flowable liner, control-flowable liner without separately curing, control-cured dual cure composite resin cement groups.However there were no significant differences between dual-cure composite resin cement without separately curing-control,cured flowable liner-cured dual cure composite resin cement, flowable liner without separately curing-dual cure composite resin cement without separately

  20. Propiedades mecánicas de resinas compuestas modificadas o no con poliácidos Mechanical properties of resin composites modified or not with polyacids

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    JM Ruiz

    2003-12-01

    Full Text Available Objetivo: Determinar la resistencia a la flexión y el módulo de elasticidad de cinco resinas compuestas: Tetric Ceram, Ecusit, Spectrum TPH, Filtek Z-250, Degufill mineral; y dos resinas modificadas con poliácidos: Luxat e lonosit. Material y método: Se prepararon cinco muestras de cada material en un molde metálico rectangular (22x2x2 mm. Las muestras fueron polimerizadas, primero en el centro y luego en ambos extremos con una lámpara de luz halógena y después se conservaron en agua a 37° C durante 48 horas. Las muestras se pulieron para eliminar la capa de resina superficial y se sometieron al ensayo de flexión en 3 puntos con una máquina de tracción universal Instron con una velocidad de travesaño de 1mm/min. Los resultados (MPa fueron analizados mediante los tests de ANOVA y Student-Newman-Keuls (p The aim of this study was to determine the flexural strength and modulus of elasticity of five resin composites: Tetric Ceram, Ecusit, Spectrum TPH, Filtek Z-250, Degufill mineral; and two polyacid-modified resin composites: Luxat e lonosit. Five rectangular specimens of each material were prepared (22x2x2 mm. They were light-cured, first in the middle and after in both extremes, by means of a visible-light curing unit. The specimens were stored in water at 37° C for 48 hours and ground to eliminate the resin layer inhibited by oxygen. Three-point bending test was performed in an universal testing machine (Instron at a cross-head speed of 1mm/min. Results were expressed in MPa and analysed by ANOVA and Student-Newman-Keuls tests (p <0.05. Flexural strength and modulus of elasticity of the polyacid-modified resin composite, lonosit, were significantly lower than the values obtained for the rest of the materials evaluated.

  1. 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.

  2. 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.

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

    Science.gov (United States)

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

    2010-02-01

    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.

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

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    Beheshteh Malek Afzali

    2016-04-01

    Full Text Available Objectives: 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.Materials and Methods: 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 (P< 0.05.Results: There was no significant difference in ΔE* values between the two types of composite resins (P>0.05. In both composite materials, the difference among the solutions was not significant (P>0.05. Conclusion: 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.

  5. Color stability of bulk-fill and incremental-fill resin-based composites polished with aluminum-oxide impregnated disks

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    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.

  6. Microbiological characterization and effect of resin composites in cervical lesions

    Science.gov (United States)

    Carlo, Bonfanti; Piccinelli, Giorgio; Faus-Matoses, Vicente; Cerutti, Antonio

    2017-01-01

    Background Non carious cervical lesions associated to muscle hyperfunctions are increasing. Microhybrid resin composites are used to restore cervical abfractions. The purpose of this study was to investigate if resin composites modify tooth plaque, inducing an increment of cariogenic microflora and evaluate their effect, in vivo and in vitro, against S. mutans. Material and Methods Eight abfractions were restored with two microhybrid resin composites (Venus, Heraeus-Kulzer® and Esthet-X, Dentsply®), after gnatological therapy, in three patients with muscle hyperfunctions. For each abfraction three samples of plaque were taken from the cervical perimeter: before the restoration, one week and three months after restoration. The samples were evaluated both by traditional microbiological methods and by Polymerase Chain Reaction (PCR). In vitro, disk-shaped specimens of the two composites were prepared to estimate the effects against pre-cultured S. mutans, after incubation at 37°C for 24h and assessed by a turbidimetric technique. Results In vivo no differences were found in plaque growth, for all samples, before and after restoration with both composites; in vitro, instead, a significant reduction of S. mutans growth was found between specimens of two composites (Mann-Whitney U-test p>0,06). Conclusions In this study a relevant consideration was elicited: composite materials, in vivo, do not modify plaque composition of non carious cervical lesions to a potential cariogenic plaque. Key words:Abfraction, restoration, S. mutans, composite, class V. PMID:28149461

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

    Science.gov (United States)

    Shembish, Fatma A; Tong, Hui; Kaizer, Marina; Janal, Malvin N; Thompson, Van P; Opdam, Niek J; Zhang, Yu

    2016-04-01

    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. Fully anatomically shaped monolithic resin composite molar crowns (Lava Ultimate, n=24) and leucite reinforced glass-ceramic crowns (IPS Empress CAD, n=24) were fabricated using CAD/CAM systems. Crowns were cemented on aged dentin-like resin composite tooth replicas (Filtek Z100) with resin-based cements (RelyX Ultimate for Lava Ultimate or Multilink Automix for IPS Empress). Three step-stress profiles (aggressive, moderate and mild) were employed for the accelerated sliding-contact mouth-motion fatigue test. Twenty one crowns from each group were randomly distributed among these three profiles (1:2:4). Failure was designated as chip-off or bulk fracture. Optical and electron microscopes were used to examine the occlusal surface and subsurface damages, as well as the material microstructures. The resin composite crowns showed only minor occlusal damage during mouth-motion step-stress fatigue loading up to 1700N. Cross-sectional views revealed contact-induced cone cracks in all specimens, and flexural radial cracks in 2 crowns. Both cone and radial cracks were relatively small compared to the crown thickness. Extending these cracks to the threshold for catastrophic failure would require much higher indentation loads or more loading cycles. In contrast, all of the glass-ceramic crowns fractured, starting at loads of approximately 450N. Monolithic CAD/CAM resin composite crowns endure, with only superficial damage, fatigue loads 3-4 times higher than those causing catastrophic failure in glass-ceramic CAD crowns. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Shear Bond Strength of Self-Adhering Flowable Composite and Resin-modified Glass Ionomer to Two Pulp Capping Materials

    Science.gov (United States)

    Doozaneh, Maryam; Koohpeima, Fatemeh; Firouzmandi, Maryam; Abbassiyan, Forugh

    2017-01-01

    Introduction: The aim of this study was to compare the shear bond strength of a self-adhering flowable composite (SAFC) and resin-modified glass ionomer (RMGI) to mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement. Methods and Materials: A total of 72 acrylic blocks with a central hole (4 mm in diameter and 2 mm in depth) were prepared. The holes were filled with MTA (sub group A) and CEM cement. The specimens of both restorative materials were divided into 6 groups; overall there were 12 groups. In groups 1 and 4, SAFC was used without bonding while in groups 2 and 5 SAFC was used with bonding agent. In all these groups the material was placed into the plastic mold and light cured. In groups 3 and 6, after surface conditioning with poly acrylic acid and rinsing, RMGI was placed into the mold and photo polymerized. After 24 h, the shear bond strength values were measured and fracture patterns were examined by a stereomicroscope. Data were analyzed using the two-way ANOVA and student’s t-test. Results: The use of bonding agent significantly increased the shear bond strength of FC to MTA and CEM cement (P=0.008 and 0.00, respectively). In both materials, RMGI had the lowest shear bond strength values (2.25 Mpa in MTA and 1.32 Mpa in CEM). The mean shear bond strength were significantly higher in MTA specimen than CEM cement (P=0.003). There was a significant differences between fracture patterns among groups (P=0.001). Most failures were adhesive/mix in MTA specimen but in CEM cement groups the cohesive failures were observed in most of the samples. Conclusion: The bond strength of self-adhering flowable composite resin to MTA and CEM cement was higher than RMGI which was improved after the additional application of adhesive. PMID:28179935

  9. Effect of LED curing on the microleakage, shear bond strength and surface hardness of a resin-based composite restoration.

    Science.gov (United States)

    Oberholzer, Theunis G; Du Preez, Ignatius C; Kidd, M

    2005-06-01

    To determine the effect of Light emitting diode (LED) curing on dental resins, microleakage, shear bond strength and surface hardness of a dental composite cured with different LEDs were determined and compared with conventional halogen curing. For microleakage, Class V cavities were restored with Esthet-X, divided into groups, and exposed to one of the curing protocols (Elipar Freelight in soft start and standard modes; Ultra-Lume 2; Spectrum 800). Standard dye penetration tests were performed and the data summarised in a 2-way contingency table of observed frequencies. The Chi-square test was used (psurface hardness, samples of Esthet-X were exposed to the light-curing units (LCUs). Vickers hardness was determined on the upper and the bottom surfaces. Data was subjected to statistical analysis using ANOVA (phardness score for the halogen light was significantly lower than for the LED lights (p<0.01). The Spectrum 800 and the Elipar Freelight (soft start) have significantly higher shear bond strengths than the others (p<0.01). It was concluded that the LED source is more efficient for a comparable overall power output.

  10. 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.

  11. Indirect composite restorations luted with two different procedures: A ten years follow up clinical trial

    Science.gov (United States)

    Preti, Alessandro; Vano, Michele; Derchi, Giacomo; Mangani, Francesco; Cerutti, Antonio

    2015-01-01

    Objectives: The aim of this clinical trial was to evaluate posterior indirect composite resin restoration ten years after placement luted with two different procedures. Study Design: In 23 patients 22 inlays/onlays (Group A) were luted using a dual-cured resin composite cement and 26 inlays/onlays (Group B) were luted using a light cured resin composite for a total of 48 Class I and Class II indirect composite resin inlays and onlays. The restorations were evaluated at 2 time points: 1) one week after placement (baseline evaluation) and 2) ten years after placement using the modified USPHS criteria. The Mann-Whitney and the Wilcoxon tests were used to examine the difference between the results of the baseline and 10 years evaluation for each criteria. Results: Numerical but not statistically significant differences were noted on any of the recorded clinical parameters (p>0.05) between the inlay/onlays of Group A and Group B. 91% and 94 % of Group A and B respectively were rated as clinically acceptable in all the evaluated criteria ten years after clinical function. Conclusions: Within the limits of the study the results showed after ten years of function a comparable clinical performance of indirect composite resin inlays/onlays placed with a light cure or dual cure luting procedures. Key words:Light curing composite, dual curing composite, indirect composite restoration, inlays/onlays, clinical trial. PMID:25810842

  12. Evaluation of shear bond strength of composite resin to nonprecious metal alloys with different surface treatments

    Directory of Open Access Journals (Sweden)

    Yassini E.

    2007-07-01

    Full Text Available Background and Aim: Replacing fractured ceramometal restorations may be the best treatment option, but it is costly. Many different bonding systems are currently available to repair the fractured ceramometal restorations. This study compared the shear bond strength of composite to a base metal alloy using 4 bonding systems.Materials and Methods: In this experimental in vitro study, fifty discs, casted in a Ni-Cr-Be base metal alloy (Silvercast, Fulldent,were ground with 120, 400 and 600 grit sandpaper and divided equally into 5 groups receiving 5 treatments for veneering. Conventional feldspathic porcelain (Ceramco2, Dentsply Ceramco was applied on control group (PFM or group1 and the remaining metal discs were air- abraded for 15 seconds with 50 mm aluminum oxide at 45 psi and washed for 5 seconds under tap water.Then the specimens were dried by compressed air and the  groups were treated with one of the bonding systems as follows: All-Bond 2 (AB, Ceramic Primer (CP, Metal Primer II (MP and Panavia F2 (PF. An opaque composite (Foundation opaque followed by a hybrid composite (Gradia Direct was placed on the treated metal surface and light cured separately. Specimens were stored in distilled water at 370C and thermocycled prior to shear strength testing. Fractured specimens were evaluated under a stereomicroscope. Statistical analysis was performed with one way ANOVA and Tukey HSD tests. P<0.05 was considered as the level of significance.Results: Mean shear bond strengths of the groups in MPa were as follows: PFM group 38.6±2, All-Bond 2 17.06±2.85, Ceramic Primer 14.72±1.2, Metal Primer II 19.04±2.2 and Panavia F2 21.37±2.1. PFM group exhibited the highest mean shear bond strength and Ceramic Primer showed the lowest. Tukey's HSD test revealed the mean bond strength of the PFM group to be significantly higher than the other groups (P<0.001. The data for the PF group was significantly higher than AB and CP groups (P<0.05 and the shear

  13. Physical Properties of a New Sonically Placed Composite Resin Restorative Material

    Science.gov (United States)

    2013-06-06

    resins . Packable composite resins were first introduced as an alternative to amalgam .10 They are characterized by a high filler load and a filler...clearance: -"_Paper _Article _ Book _ Poster _ Presentation _Other 6. Title: Physical Properties of a New Sonically Placed Composite Resin Restorative...Properties of a New Sonically Placed Composite Resin Restorative Material ABSTRACT A new nanohybrid composite activated by sonic energy (SonicFill

  14. The application of nanotechnology in the improvement of dental composite resins

    Institute of Scientific and Technical Information of China (English)

    Xia Yang; Xie Haifeng; Zhang Feimin; Gu Ning

    2012-01-01

    In this paper, nanotechnology for the improvement of dental composite resins has been reviewed in the back- ground of the existing shortcomings, focusing on the improvement for polymerization shrinkage, anti-bacterial properties and mechanical properties of composite resins. The results show that the use of nanotechnology and nano materials can be an effective method to improve the performance of dental composite resins in a various ways. At last, the paper also discusses the perspective about the dental composite resins.

  15. Mechanical and Physical Properties and Adhesion Durability of Flowable Resin Composite

    OpenAIRE

    金丸, 充徳; カナマル, ミツノリ; Mitsunori, KANAMARU

    2004-01-01

    The purpose of this study was to examine the mechanical and physical properties and adhesion durability to bovine dentin of the flowable resin composites in comparison with those of conventional resin composites and glass ionomers. In this experiment, four flowable resin composites, two conventional resin composites and two glass ionomers were used. The consistency, thermal expansion coefficiency, compressive strength, diametral tensile strength, brittleness, Vickers hardness, elastic modulus...

  16. The Basic Ply Properties of a Kevlar 49/Epoxy Resin Composite System,

    Science.gov (United States)

    1983-11-01

    Fibre 4 2.3 Composite 4 3 Results 7 3.1 Resin Properties 7 3.2 Composite Properties 9 4 Discussion 14 4.1 Resin System 14 4.2 Composite System 15 5...of the fibre creels before and after fabrication and from the weight of the composite. 3 RESULTS 3.1 Resin Properties TABLE I Resin Tensile Properties

  17. The effect of resin infiltration and oxidative pre-treatment on microshear bond strength of resin composite to hypomineralised enamel.

    Science.gov (United States)

    Chay, Pui Ling; Manton, David J; Palamara, Joseph E A

    2014-07-01

    Reduced bond strengths of resin composites to hypomineralised enamel increase restorative failure. To investigate if the adhesion of resin composite to hypomineralised enamel can be improved by pre-treatments: resin infiltration, oxidative pre-treatment followed by a resin infiltration, or oxidative pre-treatment. Twenty-one enamel specimens in each of five Groups: 1) Normal enamel; 2) Hypomineralised enamel; 3) Hypomineralised enamel pre-treated with a resin infiltrant, (Icon(®)); 4) Hypomineralised enamel pre-treated with 5.25% sodium hypochlorite then treatment with resin infiltrant; 5) Hypomineralised enamel pre-treated with 5.25% sodium hypochlorite. A resin composite rod was bonded to each specimen using Clearfil™ SE bond as the adhesive (hereafter termed 'routine bonding'), then subjected to microshear bond strength (MSBS) testing. Overall, the mean MSBS between the five groups differed significantly (P = 0.001). Pre-treatment of hypomineralised enamel with 5.25% sodium hypochlorite with or without subsequent resin infiltration in Groups 4 and 5 prior to routine bonding resulted in increased mean MSBS compared to Groups 2 and 3, with mean MSBS values not differing significantly when compared to routine bonding to normal enamel. Increased bond strength of resin composite to hypomineralised enamel was obtained by pre-treatment of hypomineralised enamel specimens with 5.25% sodium hypochlorite with or without subsequent resin infiltration. © 2013 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Flexural properties of experimental nanofiber reinforced composite are affected by resin composition and nanofiber/resin ratio.

    Science.gov (United States)

    Vidotti, Hugo A; Manso, Adriana P; Leung, Victor; do Valle, Accácio L; Ko, Frank; Carvalho, Ricardo M

    2015-09-01

    To evaluate the influence of different resin blends concentrations and nanofibers mass ratio on flexural properties of experimental Poliacrylonitrile (PAN) nanofibers reinforced composites. Poliacrylonitrile (PAN) nanofibers mats were produced by electrospinning and characterized by tensile testing and scanning electron microscopy (SEM). Experimental resin-fiber composite beams were manufactured by infiltrating PAN nanofiber mats with varied concentrations of BisGMA-TEGDMA resin blends (BisGMA/TEGDMA: 30/70, 50/50 and 70/30weight%). The mass ratio of fiber to resin varied from 0% to 8%. Beams were cured and stored in water at 37°C. Flexural strength (FS), flexural modulus (FM) and work of fracture (WF) were evaluated by three-point bending test after 24h storage. The tensile properties of the PAN nanofibers indicated an anisotropic behavior being always higher when tested in a direction perpendicular to the rotation of the collector drum. Except for WF, the other flexural properties (FS and FM) were always higher as the ratio of BisGMA to TEGDMA increased in the neat resin beams. The addition of different ratios of PAN fibers did not affect FS and FM of the composite beams as compared to neat resin beams (p>0.05). However, the addition of fibers significantly increased the WF of the composite beams, and this was more evident for the blends with higher TEGDMA ratios (presin blends did not negatively affect the properties of the composite and resulted in an increase in toughness that is a desirable property for a candidate material for prosthodontics application. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  19. Resin cement to indirect composite resin bonding: effect of various surface treatments.

    Science.gov (United States)

    Kirmali, Omer; Barutcugil, Cagatay; Harorli, Osman; Kapdan, Alper; Er, Kursat

    2015-01-01

    Debonding at the composite-adhesive interface is a major problem for indirect composite restorations. The aim of this study was to evaluate the bond strength (BS) of an indirect composite resin after various surface treatments (air-abrasion with Al2O3, phosphoric acid-etchig and different applications of NdYAG laser irradiations). Fifty composite disks were subjected to secondary curing to complete polymerization and randomly divided into five experimental groups (n = 10) including Group 1, untreated (control); Group 2, phosphoric acid-etched; Group 3, air-abrasion with Al2 O3 ; Group 4, Nd:YAG laser irradiated with non-contact and Group 5, Nd:YAG laser irradiated with contact. They were then bonded to resin cement and shear BS was determined in a universal testing device at a crosshead speed of 1 mm/min. One way analysis of variance (ANOVA) and Tukey post-hoc tests were used to analyze the BS values. The highest BS value was observed in Group 4 and followed by Group 3. Tukey test showed that there was no statistical difference between Group1, 2 and 5. Furthermore, differences in BSs between Group 4 and the other groups except Group 3 were significant (p composite and resin cement. © Wiley Periodicals, Inc.

  20. Use of dental adhesives as modeler liquid of resin composites.

    Science.gov (United States)

    Münchow, Eliseu Aldrighi; Sedrez-Porto, José Augusto; Piva, Evandro; Pereira-Cenci, Tatiana; Cenci, Maximiliano Sergio

    2016-04-01

    Resin adhesives (RA) have been applied between resin composite (RC) increments, but there is no consensus on the impact of this technique on the properties of the final restoration. This study evaluated the effect of the presence of RA between RC layers on physical properties, translucency and long-term color stability of the restorative material. Scotchbond™ Multi-Purpose (bond, 3M ESPE) and Adper™ Single Bond 2 (3M ESPE) were used as RA, and Filtek™ Z350 (3M ESPE) as RC. Specimens containing RA were prepared by applying 3 layers of the adhesive between 4 increments of RC; adhesive-free specimens were also used (control). Tests of water sorption and solubility, mechanical performance (microtensile cohesive strength, flexural strength, and flexural modulus, after immediate and long-term water storage), and translucency and color stability (after immediate and 1, 7, 90, and 180 days of water or wine storage) were performed. Scanning electron microscopy (SEM) images were also taken from the fractured specimens (flexural strength test). Data were analyzed using ANOVA and Tukey test (padhesive resin (SBMP). This study is the first to show positive results from the use of resin adhesives as modeler liquid of resin composite, which is common in clinical practice. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  1. Composite resin fillings and inlays. An 11-year evaluation

    DEFF Research Database (Denmark)

    Pallesen, Ulla; Qvist, Vibeke

    2003-01-01

    The purpose of this randomized, clinical study was to evaluate the clinical performance of composite resin materials used for fillings and indirect inlays. Twenty-eight sets of five class II restorations (two fillings, three inlays) were placed in 88 premolars and 52 molars in 28 adults. Brillian...

  2. 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

  3. 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 attribu

  4. BACTERIAL ADHESION TO DENTAL AMALGAM AND 3 RESIN COMPOSITES

    NARCIS (Netherlands)

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

    1995-01-01

    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

  5. Bond strength of resin composite to differently conditioned amalgam

    NARCIS (Netherlands)

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

    2006-01-01

    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

  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. 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

  8. 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

    This study determined whether the strength with which resin composite bonds to dentin is influenced by variations in the curing rate of resin composites. Resin composites were bonded to the dentin of extracted human molars. Adhesive (AdheSE, Ivoclar Vivadent) was applied and cured (10 seconds...

  9. The effect of resin thickness on polymerization characteristics of silorane-based composite resin

    Directory of Open Access Journals (Sweden)

    Sung-Ae Son

    2014-11-01

    Full Text Available Objectives This study examined the influence of the resin thickness on the polymerization of silorane- and methacrylate-based composites. Materials and Methods One silorane-based (Filtek P90, 3M ESPE and two methacrylate-based (Filtek Z250 and Z350, 3M ESPE composite resins were used. The number of photons were detected using a photodiode detector at the different thicknesses (thickness, 1, 2 and 3 mm specimens. The microhardness of the top and bottom surfaces was measured (n = 15 using a Vickers hardness with 200 gf load and 15 sec dwell time conditions. The degree of conversion (DC of the specimens was determined using Fourier transform infrared spectroscopy (FTIR. Scratched powder of each top and bottom surface of the specimen dissolved in ethanol for transmission FTIR spectroscopy. The refractive index was measured using a Abbe-type refractometer. To measure the polymerization shrinkage, a linometer was used. The results were analyzed using two-way ANOVA and Tukey's test at p < 0.05 level. Results The silorane-based resin composite showed the lowest filler content and light attenuation among the specimens. P90 showed the highest values in the DC and the lowest microhardness at all depth. In the polymerization shrinkage, P90 showed a significantly lower shrinkage than the rest two resin products (p < 0.05. P90 showed a significantly lower refractive index than the remaining two resin products (p < 0.05. Conclusions DC, microhardness, polymerization rate and refractive index linearly decreased as specimen thickness linearly increased. P90 showed much less polymerization shrinkage compared to other specimens. P90, even though achieved the highest DC, showed the lowest microhardness and refractive index.

  10. Light Curing 3 D Printing Materials%光固化3D打印高分子材料

    Institute of Scientific and Technical Information of China (English)

    谢彪; 王小腾; 邱俊峰; 林润雄

    2014-01-01

    快速成型(RP)技术是近几十年发展起来的一项新兴技术,3D打印就是其中一种非常有前途的,被誉为推动了第三次工业革命快速发展的快速成型技术。本文就3D打印之一的光固化3D打印进行简单介绍,对光固化3D打印材料的组分、特点进行较详细的阐述,并对光固化3D打印高分子材料未来予以展望。%Rapid prototyping(RP)technology is a new technology developed in recent decades,3D printing,one kind of these rapid prototyping technology,is very promising and known as the promoted the rapid development of the third industrial revolution. This paper gave a briefintroduction to the light curing 3D printing,the light curing composition, characteristics of 3D printing materials were described in detail,and gave the expectation of 3D printing light curing polymer.

  11. Implications of resin-based composite (RBC) restoration on cuspal deflection and microleakage score in molar teeth: Placement protocol and restorative material.

    Science.gov (United States)

    McHugh, Lauren E J; Politi, Ioanna; Al-Fodeh, Rami S; Fleming, Garry J P

    2017-09-01

    To assess the cuspal deflection of standardised large mesio-occluso-distal (MOD) cavities in third molar teeth restored using conventional resin-based composite (RBC) or their bulk fill restorative counterparts compared with the unbound condition using a twin channel deflection measuring gauge. Following thermocycling, the cervical microleakage of the restored teeth was assessed to determine marginal integrity. Standardised MOD cavities were prepared in forty-eight sound third molar teeth and randomly allocated to six groups. Restorations were placed in conjunction with (and without) a universal bonding system and resin restorative materials were irradiated with a light-emitting-diode light-curing-unit. The dependent variable was the restoration protocol, eight oblique increments for conventional RBCs or two horizontal increments for the bulk fill resin restoratives. The cumulative buccal and palatal cuspal deflections from a twin channel deflection measuring gauge were summed, the restored teeth thermally fatigued, immersed in 0.2% basic fuchsin dye for 24h, sectioned and examined for cervical microleakage score. The one-way analysis of variance (ANOVA) identified third molar teeth restored using conventional RBC materials had significantly higher mean total cuspal deflection values compared with bulk fill resin restorative restoration (all presin restored teeth had significantly the lowest microleakage scores compared with Tetric EvoCeram Bulk Fill (bonded and non-bonded) teeth (all presin restoratives behave in a similar manner when used to restore standardised MOD cavities in third molar teeth. It would appear that light irradiation of individual conventional RBCs or bulk fill resin restoratives may be problematic such that material selection is vital in the absence of clinical data. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  12. Depth of Cure of New Flowable Composite Resins

    Science.gov (United States)

    2012-03-30

    Flowable composites were introduced to the dental community in the late 1990’s (Ikeda, 2009; Bayne , 1998). The advantage of flowable composite-based...allowing the increased resin to reduce the viscous nature of the material (Ikeda, 2009; Bayne 1998). They also exhibit low wear resistance (Ikeda...Oper Dent 2008; 33:31-6. Bayne SC, Thompson JY, Swift EJ Jr, Stamatiades P, Wilkerson M. A characterization of first-generation flowable

  13. Resin-based composite as a direct esthetic restorative material.

    Science.gov (United States)

    Malhotra, Neeraj; Mala, Kundabala; Acharya, Shashirashmi

    2011-06-01

    The search for an ideal esthetic material for tooth restoration has resulted in significant improvements in both materials and the techniques for using them. Various resin-based composite (RBC) materials have recently been introduced into the market that offer improved esthetic and physical properties. This article reviews RBCs, including their compositions, advantages, and disadvantages, that are contemporary to today's clinical practice as well as those that are under research consideration and/ or in clinical trial phase.

  14. 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; Faughnan, Patrick D.; Batterson, Lawrence M.; Caraccio, Anne J.; Sampson, Jeffery W.

    2013-01-01

    Engineers today are presented with the opportunity to design and build the next generation of space vehicles out of the lightest, strongest, and most durable materials available. Composites offer excellent structural characteristics and outstanding reliability in many forms that will be utilized in future aerospace applications including the Commercial Crew and Cargo Program and the Orion space capsule. NASA's Composites for Exploration (CoEx) project researches the various methods of manufacturing composite materials of different fiber characteristics while using proven infusion methods of different resin compositions. Development and testing on these different material combinations will provide engineers the opportunity to produce optimal material compounds for multidisciplinary applications. Through the CoEx project, engineers pursue the opportunity to research and develop repair patch procedures for damaged spacecraft. Working in conjunction with Raptor Resins Inc., NASA engineers are utilizing high flow liquid infusion molding practices to manufacture high-temperature composite parts comprised of intermediate modulus 7 (IM7) carbon fiber material. IM7 is a continuous, high-tensile strength composite with outstanding structural qualities such as high shear strength, tensile strength and modulus as well as excellent corrosion, creep, and fatigue resistance. IM7 carbon fiber, combined with existing thermoset and thermoplastic resin systems, can provide improvements in material strength reinforcement and deformation-resistant properties for high-temperature applications. Void analysis of the different layups of the IM7 material discovered the largest total void composition within the [ +45 , 90 , 90 , -45 ] composite panel. Tensile and compressional testing proved the highest mechanical strength was found in the [0 4] layup. This paper further investigates the infusion procedure of a low-cost/high-performance BMI resin into an IM7 carbon fiber material and the

  15. 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.

  16. Microwave absorption properties of graphite flakes-phenolic resin composite

    Science.gov (United States)

    Gogoi, Jyoti P.; Gogoi, Pragyan J.; Bhattacharyya, Nidhi S.

    2013-01-01

    In the present investigation, microwave absorption properties of a conductor back single layer designed on graphite flakes (GF)-novolac phenolic resin (NPR) composites is studied. The complex permittivity of the developed composite enhance for higher GF percentages. The reflection loss(RL) measured using E8362C VNA shows a maximum RL values -25 dB at 9.8 GHz for 7 wt. % composition with -10 dB bandwidth of 0.3 GHz. The developed composites are being light weight and cost effective shows potential to be used as dielectric absorber.

  17. 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.

  18. Cariogenic bacteria degrade dental resin composites and adhesives.

    Science.gov (United States)

    Bourbia, M; Ma, D; Cvitkovitch, D G; Santerre, J P; Finer, Y

    2013-11-01

    A major reason for dental resin composite restoration replacement is related to secondary caries promoted by acid production from bacteria including Streptococcus mutans (S. mutans). We hypothesized that S. mutans has esterase activities that degrade dental resin composites and adhesives. Standardized specimens of resin composite (Z250), total-etch (Scotchbond Multipurpose, SB), and self-etch (Easybond, EB) adhesives were incubated with S. mutans UA159 or uninoculated culture medium (control) for up to 30 days. Quantification of the BisGMA-derived biodegradation by-product, bishydroxy-propoxy-phenyl-propane (BisHPPP), was performed by high-performance liquid chromatography. Surface analysis of the specimens was performed by scanning electron microscopy (SEM). S. mutans was shown to have esterase activities in levels comparable with those found in human saliva. A trend of increasing BisHPPP release throughout the incubation period was observed for all materials and was more elevated in the presence of bacteria vs. control medium for EB and Z250, but not for SB (p adhesives; degree of degradation was dependent on the material's chemical formulation. This finding suggests that the resin-dentin interface could be compromised by oral bacteria that contribute to the progression of secondary caries.

  19. Development of a composite resin disclosing agent based on the understanding of tooth staining mechanisms.

    Science.gov (United States)

    Abdallah, Mohamed-Nur; Light, Nathan; Amin, Wala M; Retrouvey, Jean-Marc; Cerruti, Marta; Tamimi, Faleh

    2014-06-01

    To characterize the surface composition of dental enamel and composite resin, assess the ability of dyes with different affinities to stain these surfaces, and use this information to develop a disclosing agent that stains composite resin more than dental enamel. One hundred and ten sound extracted teeth were collected and 60 discs of composite resin, 9 mm diameter and 3 mm thick, were prepared. X-ray photoelectron spectroscopy (XPS) was employed to determine the elemental composition on the different surfaces. A tooth shade spectrophotometer was used to assess the change in shade after staining the surfaces with different dyes. XPS analysis revealed that surfaces of both outer dental enamel and composite resin contained relatively high amounts of carbon, specifically hydrocarbons. Both dental enamel and composite surfaces were stainable with the hydrophobic dye (pcomposite resin was stained more than the dental enamel (pcomposite resin might explain their high affinity to be stained by food and beverages containing hydrophobic molecules. The composite resin is more stainable by hydrophobic dyes than dental enamel. We used this information to develop an agent for disclosing composite resins that could be used to visualize composite resins that need to be removed. Removal of composite resin can be problematic, time consuming and stressful to the dental practitioner. A composite disclosing agent would help the dental practitioner identify the composite resin and facilitate its removal without damaging the adjacent healthy tooth tissues. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. 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...

  1. Blue light curing units--a dermatological hazard?

    Science.gov (United States)

    Chadwick, R G; Traynor, N; Moseley, H; Gibbs, N

    1994-01-08

    The setting reactions of a large number of dental materials are activated upon exposure to visible blue light emitted from a curing unit. Although the wavelength (lambda) from such devices is principally in the visible spectrum (lambda > 400 nm) a small amount of ultraviolet radiation (UV) is also present. Little attention has been paid to the consequences of such exposure upon the skin of dental surgeons' fingers. This investigation studied the level of UVA I (lambda = 340-400 nm) emitted by three commonly used polymerisation sources and assessed the level of protection afforded by six brands of surgical glove. The integrated irradiances of the Translux, Topaz T100 and Heliomat units in the UVA I range were 15861, 3611 and 305 mW/m2 respectively. For all gloves the mean % transmission, at lambda = 400 nm, was less than 4% with the exception of one brand where, in the stretched state, the level of transmission was 7%. It is concluded that the risk of initiating adverse dermatological consequences as a result of exposure to UVA I, emitted by light polymerisation units, is minimal in normal usage. The combined effects of exposure to radiation of this type and contamination of the fingers with quantities of irritant chemicals, such as found in many dental materials, are unknown. Due to the ability of the gloves to shield the skin from both chemicals and UVA I it is recommended that gloves are routinely worn for all light curing procedures.

  2. 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)

  3. Synthesis of Photochromic AgCl-Urethane Resin Composite Films

    Directory of Open Access Journals (Sweden)

    Hidetoshi Miyazaki

    2012-01-01

    Full Text Available AgCl-resin photochromic composite films were prepared using AgNO3, HCl-EtOH, CuCl2 solution, and a liquid-state urethane resin as starting materials. The obtained composite films showed a photochromic property. The rate of darkening of the composite film increased after mixing with CuCl2. The AgCl particle size in the film without heat treatment was 6–20 nm, and that of the heat-treated film was 25–80 nm; these results were confirmed using TEM observations. The fading rate of the film without heat treatment was higher than that of the heat-treated films.

  4. Wear characteristics of trimethylolpropane trimethacrylate filler-containing resins for the full crown restoration of primary molars.

    Science.gov (United States)

    Wada, Kanae; Ikeda, Eri; Wada, Junichiro; Inoue, Go; Miyasaka, Munenaga; Miyashin, Michiyo

    2016-01-01

    Although the demand for aesthetic restoration of primary molars has increased, the full-crown restorations using resin and the details of the wear characteristics of trimethylolpropane trimethacrylate (TMPT) filler containing resins for primary molars are not well understood. This study was conducted to determine whether new light-cured composite resin (Fantasista) and 4-META/MMATBB resin (Bondfill SB) are appropriate for full crown restoration of primary molars by evaluating their wear characteristics. Both resins products contain TMPT filler. The properties of the resins were evaluated through in vitro impacting-sliding wear tests; the wear properties of the opposing enamel specimens used in the tests were also studied. The properties of the resins were compared with those of Litefill, MetafilC, and Clearfil FII, which had been evaluated previously. Fantasista exhibited simple shape of wear that was suggestive of a higher wear resistance than that of Litefill. Fantasista caused the least damage to the antagonistic primary enamel.

  5. [Marginal leakage in composite resin restorations in posterior teeth. Effect of material, cavity preparation and enamel conditioning at the cervical level].

    Science.gov (United States)

    Marotta Araujo, R; da Silva Filho, F P; Dias Mendes, A J

    1990-01-01

    The purpose of this "in vitro" study was to investigate the cervical marginal leakage in class II restorations with chemically cured resin (P10) and light-cured resin (P30) in two types of cavities: conventional and adhesive. The effect of acid-etching in this area was also observed. Dentine adhesive Scotchbond was used in all experimental groups. Leakage was evidenced by Rodamina B dye penetration after thermocycling procedure between 10 degrees C and 50 degrees C temperature and analysed by using Zeiss Stereoscopic Magnifying Glass (10 X). According to the results obtained marginal leakage occurred in all experimental groups, with lower percentage for adhesives cavities when enamel acid-etching and light-cured resin P30 was used.

  6. 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.

  7. Color stability of bulk-fill and incremental-fill resin-based composites polished with aluminum-oxide impregnated disks.

    Science.gov (United States)

    Koc-Vural, Uzay; Baltacioglu, Ismail; Altinci, Pinar

    2017-05-01

    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. 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). 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 composites can be significantly affected by the polishing procedures.

  8. Heat conduciton properties of flowable composite resins

    Directory of Open Access Journals (Sweden)

    Muhammet Yalçin

    2016-01-01

    Full Text Available Objectives: To investigate and compare heat conduction of different flowable composites. Materials and Methods: In this study, four different flowable composites; GC Gradia Direct LoFlo (GC Corporation, Tokyo, Japan, Filtek Ultimate (3M ESPE, St. Paul, USA, Grandio Flow (VOCO GmbH, Cuxhaven, Germany and SDI Wave (SDI, Victoria, Australia were used. Flowable composites were placed into standard molds and used according to manufacturer instructions. The samples were prepared for every brand of flowable composites. The Heat Conduction Unit's (P. A. Hilton Ltd., England linear heat conduction module was used in determining the flowable composites heat conductivity. The data were statistically analyzed by Mann–Whitney U-test (SPSS 13.0, SPSS, Chicago, IL, USA. Results: Heat conduction values of flowable composites were found different each other. Results for GC Gradia Direct and Grandio Flow were significantly different from 3M ESPE and SDI (P 0.005. Conclusions: Within the limits of this study, flowable composites transmit the heat. However, results for GC Gradia Direct and Grandio Flow were significantly different from 3M ESPE and SDI.

  9. Comparative evaluation of shear bond strength of conventional composite resin and nanocomposite resin to sandblasted primary anterior stainless steel crown

    Directory of Open Access Journals (Sweden)

    Khatri A

    2007-06-01

    Full Text Available To evaluate and compare the shear bond strength of conventional composite resin and nanocomposite resin to sandblasted primary anterior stainless steel crown. The study samples consisted of 30 primary anterior stainless steel crowns (Unitek TM , size R4, embedded in resin blocks with crown, in test groups of 15 samples each. Mounting of the crown was done using resin block with one crown each. Sandblasting was done and the bonding agent Prime and Bond NT (Dentsply was applied on the labial surface of the primary anterior sandblasted crown. The composite resin and nanocomposite resin were placed into the well of Teflon jig and bonded to Stainless Steel Crowns. The cured samples were placed in distilled water and stored in incubator at 37°C for 48 hours. Shear bond strength was measured using universal testing machine (Hounsefield U.K. Model, with a capacity of 50 KN. Independent sample ′t′ test revealed a nonsignificant ( P < 0.385 difference between mean shear bond strength values of conventional and nanocomposite group. The bond strength values revealed that nanocomposite had slightly higher mean shear bond strength (21.04 ± 0.56 compared to conventional composite (20.78 ± 0.60. It was found that conventional composite resin and nanocomposite resin had statistically similar mean shear bond strength, with nanocomposite having little more strength compared to conventional composite.

  10. Penggunaan Composit Resin pada Kasus Resisi Gingiva

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    S. Suryono

    2012-06-01

    Full Text Available Background: The clinical appearance of gingival tissue play an essential role in aesthetics. Gingival morphology and color effect on the aesthetic concerns for the patient. Gingival recession can cause exposure of the underlying rootsurface and hypersensitive of the tooth. Purpose: this case reports showed the treatment of gingival recession by using gingival-shaded composite. Case and treatment: Exposed root surface is layered by gingival-shaded composite and its also improved aesthetics by replacement of the restoration. Conclusion: The use of gingival-shaded composite in the area of exposed root surface for layering improved the aesthetic and relief the sensitive denting of patient.

  11. Comparison of the effect of light-cure and dual-cure bondings on regional bond strength of fiber reinforced posts to root canal

    Directory of Open Access Journals (Sweden)

    Aminsalehi E.

    2008-04-01

    Full Text Available Background and Aim: The use of fiber reinforced posts in endodontically treated teeth has become increasingly common. But their retention in root canals must be considered seriously. The aim of this study was to evaluate the effect of light-cure and dual-cure bondings on regional bond strength of a fiber composite post.Materials and Methods: In this experimental in vitro study, 20 endodontically treated teeth were randomly divided into two groups. In the first group, a dual-cure bonding (Scotchbond Multi-Purpose Plus, 3M ESPE/USA [SBMP] was used and in the other group, a light-cure bonding (Single Bond, 3M ESPE/USA [SB] was applied according to the manufacturer's instructions. A dual-cure resin cement (Rely X ARC, 3M ESPE/USA was used to cement the post (Glassix, Harald Nordin SA,Switzerland. Coronal 8mm of cemented posts were sectioned in equal thirds using a 0.1mm diamond disc. Each slice was polished by a soft and wet abrasive paper in order to get a 2mm thickness. Loading was performed by a testing machine (Zwick/Germany at a speed of 1mm/min until the post was dislodged. Data were analyzed using one-sample Kolmogorov-Smirnov, T and ANOVA tests with P<0.05 as the level of significance.Results: There was a significant difference between the two adhesive systems in the middle third of the canal block with higher bond strength in SBMP group (p=0.02. In SB group the bond strength of the cervical region was higher than the middle and apical thirds (p<0.05. In SBMP group, there was no statistically difference between bond strength of the three regions (p=0.117.Conclusion: Based on the results of this study, dual-cure bonding could be recommended for composite post cementation into root canals, because its bond strength was more uniform in different regions of root and greater in the middle and third regions.

  12. Silicone Resin Applications for Ceramic Precursors and Composites

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    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.

  13. Dynamic thermo-mechanical properties of various flowable resin composites

    Science.gov (United States)

    Balthazard, Rémy; Vincent, Marin; Dahoun, Abdessellam; Mortier, Eric

    2016-01-01

    Background This study compared the storage modulus (E’), the loss modulus (E’’) and the loss tangent (tan δ) of various flowable resin composites. Material and Methods Grandio Flow (GRF), GrandioSo Heavy Flow (GHF), Filtek Supreme XTE (XTE) and Filtek Bulk Fill (BUL) flowable resins and Clinpro Sealant (CLI) ultra-flowable pit and fissure sealant resin were used. 25 samples were tested using a dynamical mechanical thermal analysis system in bending mode. Measurements were taken within a temperature range of 10 to 55°C. The results were statistically analyzed using mixed-effect and repeated-measure analysis of variance followed by paired multiple comparisons. Results For all the materials, the E’ values decrease with temperature, whereas the tan δ values increase. Irrespective of the temperature, GHF and GRF present E’ and E’’ values significantly higher than all the other materials and CLI presents values significantly lower than all the other materials. Observation of the values for all the materials reveals a linear progression of the tan δ values with temperature. Conclusions A variation in temperature within a physiological range generates modifications in mechanical properties without damaging the material, however. Filler content in volume terms appears to be the crucial parameter in the mechanical behavior of tested materials. Key words:Dynamic mechanical thermal analysis, elastic modulus, filler content, flowable resin composites, loss modulus, loss tangent. PMID:27957266

  14. Profile of Fluoride Release from a Nanohybrid Composite Resin

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    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.

  15. 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.

  16. 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.

  17. Alternative methods for determining shrinkage in restorative resin composites.

    Science.gov (United States)

    de Melo Monteiro, Gabriela Queiroz; Montes, Marcos Antonio Japiassú Resende; Rolim, Tiago Vieira; de Oliveira Mota, Cláudia Cristina Brainer; de Barros Correia Kyotoku, Bernardo; Gomes, Anderson Stevens Leônidas; de Freitas, Anderson Zanardi

    2011-08-01

    The purpose of this study was to evaluate polymerization shrinkage of resin composites using a coordinate measuring machine, optical coherence tomography and a more widely known method, such as Archimedes Principle. Two null hypothesis were tested: (1) there are no differences between the materials tested; (2) there are no differences between the methods used for polymerization shrinkage measurements. Polymerization shrinkage of seven resin-based dental composites (Filtek Z250™, Filtek Z350™, Filtek P90™/3M ESPE, Esthet-X™, TPH Spectrum™/Dentsply 4 Seasons™, Tetric Ceram™/Ivoclar-Vivadent) was measured. For coordinate measuring machine measurements, composites were applied to a cylindrical Teflon mold (7 mm × 2 mm), polymerized and removed from the mold. The difference between the volume of the mold and the volume of the specimen was calculated as a percentage. Optical coherence tomography was also used for linear shrinkage evaluations. The thickness of the specimens was measured before and after photoactivation. Polymerization shrinkage was also measured using Archimedes Principle of buoyancy (n=5). Statistical analysis of the data was performed with ANOVA and the Games-Howell test. The results show that polymerization shrinkage values vary with the method used. Despite numerical differences the ranking of the resins was very similar with Filtek P90 presenting the lowest shrinkage values. Because of the variations in the results, reported values could only be used to compare materials within the same method. However, it is possible rank composites for polymerization shrinkage and to relate these data from different test methods. Independently of the method used, reduced polymerization shrinkage was found for silorane resin-based composite. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Laboratory evaluation of several nanofilled dental resin composites: mechanical and chemical properties

    OpenAIRE

    Scotti, Nicola

    2015-01-01

    The present thesis focused on nanofilled dental resins. The first year activity focused on depth of cure analysis of nanofilled composites. The second year activity focused on hardness, depth of cure and shrinkage stress analysis of bulk fill resin composites. The third year focused on degree of conversion and hardness of nanofilled resin cements. 2013/2014

  19. Laboratory evaluation of several nanofilled dental resin composites: mechanical and chemical properties

    OpenAIRE

    Scotti, Nicola

    2015-01-01

    The present thesis focused on nanofilled dental resins. The first year activity focused on depth of cure analysis of nanofilled composites. The second year activity focused on hardness, depth of cure and shrinkage stress analysis of bulk fill resin composites. The third year focused on degree of conversion and hardness of nanofilled resin cements. 2013/2014

  20. Effects of cement-curing mode and light-curing unit on the bond durability of ceramic cemented to dentin

    Directory of Open Access Journals (Sweden)

    Sheila Pestana Passos

    2013-04-01

    Full Text Available The aim of this study was to evaluate the effects of different light-curing units and resin cement curing types on the bond durability of a feldspathic ceramic bonded to dentin. The crowns of 40 human molars were sectioned, exposing the dentin. Forty ceramic blocks of VITA VM7 were produced according to the manufacturer's recommendations. The ceramic surface was etched with 10% hydrofluoric acid / 60s and silanized. The dentin was treated with 37% phosphoric acid / 15s, and the adhesive was applied. The ceramic blocks were divided and cemented to dentin according to resin cement / RC curing type (dual- and photo-cured, light-curing unit (halogen light / QTH and LED, and storage conditions (dry and storage / 150 days + 12,000 cycles / thermocycling. All blocks were stored in distilled water (37°C / 24h and sectioned (n = 10: G1 - QTH + RC Photo, G2 - QTH + RC Dual, G3 - LED + RC Photo, G4 - LED + RC Dual. Groups G5, G6, G7, and G8 were obtained exactly as G1 through G4, respectively, and then stored and thermocycled. Microtensile bond strength tests were performed (EMIC, and data were statistically analyzed by ANOVA and Tukey's test (5%. The bond strength values (MPa were: G1 - 12.95 (6.40ab; G2 - 12.02 (4.59ab; G3 - 13.09 (5.62ab; G4 - 15.96 (6.32a; G5 - 6.22 (5.90c; G6 - 9.48 (5.99bc; G7 - 12.78 (11.30ab; and G8 - 8.34 (5.98bc. The same superscript letters indicate no significant differences. Different light-curing units affected the bond strength between ceramic cemented to dentin when the photo-cured cement was used, and only after aging (LED > QTH. There was no difference between the effects of dual- and photo-cured resin-luting agents on the microtensile bond strength of the cement used in this study.

  1. Fiber Optic Systems for Light Curing Rigidization of Inflatable Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Light (UV and visible) curing composite matrix resins are being explored as an attractive means for rigidizing inflatable spacecraft for large space-deployed...

  2. Surface hardness properties of resin-modified glass ionomer cements and polyacid-modified composite resins.

    Science.gov (United States)

    Bayindir, Yusuf Ziya; Yildiz, Mehmet

    2004-11-15

    In this study the top and bottom surface hardness of two polyacid-modified composite resins (PMCRs), one resin-modified glass ionomer cement (RMGIC), and one composite resin were evaluated. The affect of water storage on their hardness was also investigated. The study was conducted using four different groups, each having five specimens obtained from fiberglass die molds with a diameter of 5 mm and a height of 2 mm. Measurements were made on the top and bottom surface of each specimen and recorded after 24 hours and again at 60 days. All tested materials showed different hardness values, and the values of top surfaces of the specimens were found to be higher than the bottom surface in all test groups. There was no statistical difference in the Vickers hardness (HV) values when the test specimens were kept in water storage. In conclusion Hytac displayed microhardness values higher than Vitremer and Dyract. We found the order of HV values to be Surfil > Hytac > Dyract > Vitremer, respectively. Vitremer presented the lowest microhardness level and Surfil the highest.

  3. Handling characteristics of resin composites in posterior teeth.

    Science.gov (United States)

    Ferrari, M; Kugel, G

    1998-09-01

    In the last 10 years, tremendous improvements in strength and shade selection for resin composites have been achieved. Also, a new generation of enamel-dentin bonding systems has been developed, and patient expectations of esthetic treatment have risen. Several techniques are available for restoring posterior teeth. When a caries lesion is limited, a direct esthetic restoration is indicated. Essential elements for obtaining good, long-term clinical results for direct esthetic restorations of posterior teeth are: (1) cavity preparation; (2) knowledge of the characteristics of the three dental substrates; (3) rubber dam use and matrix and wedge placement; (4) correct use of the enamel-dentin bonding system; (5) proper selection of the resin composite material; (6) use of the multilayering technique; (7) finishing and polishing procedures; and (8) maintenance of the restoration.

  4. Factors involved in mechanical fatigue degradation of dental resin composites.

    Science.gov (United States)

    Lohbauer, U; Belli, R; Ferracane, J L

    2013-07-01

    The design of clinical trials allows for limited insights into the fatigue processes occurring in resin composites and the factors involved therein. In vitro studies, in contrast, can fundamentally narrow study interests to focus on particular degradation mechanisms and, to date, represent the major contributors to the state of knowledge on the subject. These studies show that microstructural features are important in determining strength and fracture toughness, whereas fatigue resistance is mainly related to the susceptibility of the matrix and the filler/matrix interface to mechanical and chemical degradation. In this review, we focus on fracture mechanisms occurring during fatigue, on the methods used to assess them, and on additional phenomena involved in the degradation of initial mechanical