WorldWideScience

Sample records for conventional restorative materials

  1. Reinforcement of conventional glass-ionomer restorative material with short glass fibers.

    Science.gov (United States)

    Hammouda, Ibrahim M

    2009-01-01

    This study investigated the strengthening effect of glass fibers when added to conventional glass-ionomer restorative material. Glass fibers were incorporated into glass-ionomer powder in 3 wt% and 5 wt%. The fibers used had 1 mm length and 10 microm thickness. These criteria of fiber length, diameter, and concentration represent a new approach for reinforcing conventional glass-ionomer [Medifill, conventional restorative glass-ionomer]. The mechanical properties tested were diametral tensile strength, hardness, flexural strength, flexural modulus and fracture toughness after 24-h and 7-days of storage in deionized water. Glass short fibers were mixed thoroughly into the glass-ionomer powder before mixing with the cement liquid. Samples of specific dimensions were prepared for each time interval and fiber loading according to the manufacturer's instructions and international standards. Hardness was measured using a micro-hardness tester at 100 gram applied load for 15 s. The other mechanical properties were measured using a Lloyd universal testing machine. The results showed increased diametral tensile strength, flexural strength, flexural modulus, and fracture toughness by the addition of glass fibers. There was an appreciable increase of the tested mechanical properties of glass-ionomer restorative material as a result of increasing fiber loading and water storage for 1 week. It was concluded that conventional glass-ionomer can be reinforced by the addition of short glass fibers.

  2. Adherence of Streptococcus mutans to Fiber-Reinforced Filling Composite and Conventional Restorative Materials.

    Science.gov (United States)

    Lassila, Lippo V J; Garoushi, Sufyan; Tanner, Johanna; Vallittu, Pekka K; Söderling, Eva

    2009-12-04

    OBJECTIVES.: The aim was to investigate the adhesion of Streptococcus mutans (S. mutans) to a short glass fibers reinforced semi-IPN polymer matrix composite resin. The effect of surface roughness on adhesion was also studied. For comparison, different commercial restorative materials were also evaluated. MATERIALS AND METHODS.: Experimental composite FC resin was prepared by mixing 22.5 wt% of short E-glass fibers, 22.5 wt% of IPN-resin and 55 wt% of silane treated silica fillers using high speed mixing machine. Three direct composite resins (Z250, Grandio and Nulite), resin-modified glass ionomers (Fuji II LC), amalgam (ANA 2000), fiber-reinforced composite (FRC) (everStick and Ribbond), and pre-fabricated ceramic filling insert (Cerana class 1) were tested in this study. Enamel and dentin were used as controls. The specimens (n=3/group) with or without saliva were incubated in a suspension of S. mutans allowing initial adhesion to occur. For the enumeration of cells on the disc surfaces as colony forming units (CFU) the vials with the microbe samples were thoroughly Vortex-treated and after serial dilutions grown anaerobically for 2 days at +37 degrees C on Mitis salivarius agars (Difco) containing bacitracin. Bacterial adhesion was also evaluated by using scanning electron microscopy. Surface roughness (Ra) of the materials was also determined using a surface profilometer. All results were statistically analyzed with one-way analysis of variance (ANOVA). RESULTS.: Composite FC resin and other commercial restorative materials showed similar adhesion of S. mutans, while adhesion to dentin and enamel was significantly higher (p<0.05). Surface roughness had no effect on bacterial adhesion. Saliva coating significantly decreased the adhesion for all materials (p<0.05). Composite FC resin had a significantly higher Ra value than control groups (p<0.05). CONCLUSIONS.: Short fiber-reinforced composite with semi-IPN polymer matrix revealed similar S. mutans adhesion

  3. Antimicrobial properties of conventional restorative filling materials and advances in antimicrobial properties of composite resins and glass ionomer cements-A literature review.

    Science.gov (United States)

    Farrugia, Cher; Camilleri, Josette

    2015-04-01

    It has been reported that complete caries removal from cavities during restoration of teeth is difficult. Furthermore with the tissue saving approach it is expected that more of the saved affected tissue will possibly harbor more residual bacteria. Antimicrobial restorative filling materials would be ideal to prevent the spread of caries after completion of tooth restoration, thus preventing recurrent decay and eventually restoration failure. This paper reviews the literature on the antimicrobial properties of dental restorative filling materials. Pubmed searches on the antibacterial properties of restorative materials were carried out. Keywords were chosen to assess antibacterial properties of conventional filling materials. Methods of introducing antimicrobial agents in restorative materials were also reviewed together with the methodology used to assess antimicrobial activity. 174 articles from 1983 till 2014 were included. Adhesive materials have decreased antimicrobial activity when compared to amalgams and zinc oxides. Several techniques have been employed in order to increase the antimicrobial activity of restorative materials. Although antimicrobial activity of restorative materials is important, the introduction of antimicrobial agents/techniques should not be at the expense of other material properties. Environmental changes within a material may affect the bacterial response to the antimicrobial. Bacterial adhesion to the restorative materials should be assessed. Long term assessment of antimicrobial activity is important and is clinically relevant. The use of antimicrobial dental materials is important unless such characteristics are gained to the detriment of other material properties. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  4. [New direct restorative materials].

    Science.gov (United States)

    Hickel, R; Dasch, W; Janda, R; Tyas, M; Anusavice, K

    1999-04-01

    People worldwide have become increasingly aware of the potential adverse effects on the environment, of pollution control and of toxic effects of food, drugs and biomaterials. Amalgam and its potential toxic side effects (still scientifically unproven) continue to be discussed with increasing controversy by the media in some countries. Consequently, new direct restorative materials are now being explored by dentists, materials scientists and patients who are searching for the so-called 'amalgam substitute' or 'amalgam alternative'. From a critical point of view some of the new direct restorative materials are good with respect in aesthetics, but all material characteristics must be considered, such as mechanical properties, biological effects, and longterm clinical behaviour.

  5. Fracture Resistance of Endodontically Treated Teeth Restored with 2 Different Fiber-reinforced Composite and 2 Conventional Composite Resin Core Buildup Materials: An In Vitro Study.

    Science.gov (United States)

    Eapen, Ashly Mary; Amirtharaj, L Vijay; Sanjeev, Kavitha; Mahalaxmi, Sekar

    2017-09-01

    The purpose of this in vitro study was to comparatively evaluate the fracture resistance of endodontically treated teeth restored with 2 fiber-reinforced composite resins and 2 conventional composite resin core buildup materials. Sixty noncarious unrestored human maxillary premolars were collected, endodontically treated (except group 1, negative control), and randomly divided into 5 groups (n = 10). Group 2 was the positive control. The remaining 40 prepared teeth were restored with various direct core buildup materials as follows: group 3 teeth were restored with dual-cure composite resin, group 4 with posterior composite resin, group 5 with fiber-reinforced composite resin, and group 6 with short fiber-reinforced composite resin. Fracture strength testing was performed using a universal testing machine. The results were statistically analyzed by 1-way analysis of variance and the post hoc Tukey test. Fracture patterns for each sample were also examined under a light microscope to determine the level of fractures. The mean fracture resistance values (in newtons) were obtained as group 1 > group 6 > group 4 > group 3 > group 5 > group 2. Group 6 showed the highest mean fracture resistance value, which was significantly higher than the other experimental groups, and all the fractures occurred at the level of enamel. Within the limitations of this study, a short fiber-reinforced composite can be used as a direct core buildup material that can effectively resist heavy occlusal forces against fracture and may reinforce the remaining tooth structure in endodontically treated teeth. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Flouride release from various restorative materials.

    Science.gov (United States)

    Bala, O; Uçtaşli, M; Can, H; Türköz, E; Can, M

    1997-09-01

    Fluoride release from six light-activated restorative materials, including two resinmodified glass-ionomers, two composites, and two compomers, was evaluated and compared with one conventional acid-based glass-ionomer cement. The amount and rate of release varied among the tested materials. Both resin-modified glass-ionomers and the conventional acid-base glass-ionomer cements released more fluoride then the composites and compomers (p < 0.05). Additionally, composite materials released less fluoride than compomer materials (p < 0.05). Release of fluoride by the tested materials showed a significant decrease after all the tested time intervals.

  7. [Pulp response to restorative materials].

    Science.gov (United States)

    Advokaat, J G

    1990-03-01

    Restorations may affect the pulp negatively, rather due to microleakage than to toxic properties of the materials used. Hyperalgesia occurs more frequently after restoration with composite resins than with amalgam, though the resins in contrast to amalgam may be bonded to the enamel margins. A number of recommendations are presented in order to minimize the marginal gap between cavity walls and amalgam and to prevent marginal fracture.

  8. Ormocer: An aesthetic direct restorative material; An in vitro study comparing the marginal sealing ability of organically modified ceramics and a hybrid composite using an ormocer-based bonding agent and a conventional fifth-generation bonding agent

    Directory of Open Access Journals (Sweden)

    Sarika Kalra

    2012-01-01

    Full Text Available Aims and Objectives : To compare the marginal sealing ability of ormocer with a hybrid composite using an ormocer based bonding agent and a conventional fifth generation bonding agent. Materials and Methods : Fifty four human premolars were randomly distributed into four test groups of 12 teeth each and two control groups of 3 teeth each. Class I occlusal preparation of 1.5 mm depth were made in each tooth. These were restored using the adhesive and restorative material according to the group. The restorations were finished using a standard composite finishing and polishing kit. Thermocycling between 5 o C and 55 o C was carried out. Having blocked the root apex and the entire tooth surface except 1 mm around the restoration margin, the teeth were immersed in 2% methylene blue for 48 hours, after which the dye penetration through the margins of each sample was studied under a stereomicroscope. Results and Discussion : Group IV (Admira with Admira Bond showed the minimum marginal leakage with a mean of 0.200 mm. Four samples in this group showed no microleakage at all and a maximum of 0.400 mm was seen in one sample. Group II (Spectrum TPH with Admira Bond showed the maximum leakage with a mean of 0.433 mm. One sample showed as much as 1.00 mm of microleakage. Admira when used with Admira Bond showed lesser microleakage than Spectrum TPH used with Prime & Bond NT, the difference being statistically insignificant.

  9. Interactions of liposomes with dental restorative materials.

    Science.gov (United States)

    Nguyen, Sanko; Adamczak, Malgorzata; Hiorth, Marianne; Smistad, Gro; Kopperud, Hilde Molvig

    2015-12-01

    The in vitro adsorption and retention of liposomes onto four common types of dental restorative materials (conventional and silorane-based resin composites as well as conventional and resin-modified glass ionomer cements (GIC)) have been investigated due to their potential use in the oral cavity. Uncoated liposomes (positively and negatively charged) and pectin (low- and high-methoxylated) coated liposomes were prepared and characterized in terms of particle size and zeta potential. The adsorption of liposomes was performed by immersion, quantified by fluorescence detection, and visualized by fluorescence imaging and atomic force microscopy. Positive liposomes demonstrated the highest adsorption on all four types of materials likely due to their attractive surface charge. They also retained well (minimum 40% after 60 min) on both conventional resin composite and GIC even when exposed to simulated salivary flow. Although an intermediate initial level of adsorption was found for the pectin coated liposomes, at least 70% high methoxylated-pectin coated liposomes still remained on the conventional resin composite after 60 min flow exposure. This indicates significant contribution of hydrophobic interactions in the prolonged binding of liposomes to resin composites. Based on these results, the present paper suggests two new possible applications of liposomes in the preservation of dental restorations.

  10. 四种充填材料根管充填术后磨牙抗折强度的对比%A comparative study of fracture resistance of molars restored with different materials after conventional endodontic treatment

    Institute of Scientific and Technical Information of China (English)

    杨宗范; 曾长余; 卓钺; 郭志远; 张波

    2015-01-01

    目的::比较4种不同充填材料对根管充填术后磨牙抗折强度的影响。方法:选择牙体牙根完整的成人离体下颌第一、二磨牙80个,制备牙合面洞,常规根管预备、充填后随机分成4组( n=20),分别采用银汞合金(A组)、光固化复合树脂(B组)、银粉玻璃离子(C组)、玻璃离子(D组)进行充填,用万能试验机垂直加压至样本冠根纵折,记录最大抗压载荷。结果:A、B、C、D组最大抗压载荷( N)分别为1126.15±291.66、1682.90±368.69、1614.55±424.09、1818.75±439.54(P0.05。结论:根管充填后磨牙修复,光固化复合树脂、银粉玻璃离子及玻璃离子材料抗折强度优于银汞合金。%AIM:To compare the fracture resistance of molars restored with 4 different materials after con-ventional endodontic treatment. METHODS:80 extracted molars were instrumented and then randomly divided into 4 groups(n=20). The teeth were then restored with silver amalgam(group A), light-cured composite resin(group B), glass ionomer silver reinforced restoration(group C) and glass ionomer(group D) respectively. All specimens were subjected to a vertical load to cause vertical crown and root fracture. The force required to fracture was measured. RE-SULTS:The mean fracture load values( N) of group A, B, C and D were 1126. 15 ± 291. 66, 1682. 90 ± 368. 69, 1614. 55 ± 424. 09 and 1818. 75 ± 439. 54 respectively (P0. 05). CONCLUSION:The molars restored with light-cured composite resin, glass ionomer silver reinforced restoration or glass ionomer have higher fracture resistance than those restored with silver amalgam.

  11. Restoration of primary molars using a new "compomer" material.

    Science.gov (United States)

    Swift, E J; Vann, W F

    1995-10-01

    The primary advantages of glass ionomer restorative materials are adhesion to tooth structure and release of fluoride. A new material has been recently introduced for the restoration of cervical lesions and Class I defects in primary teeth. The material combines the properties of glass ionomers with the advantages of a single-component, light-activated composite resin and is known as a "compomer". This new material contains two resins, instead of the acidic polymers found in conventional glass ionomers. The restorative material releases fluoride and can be infected directly into the cavity. With its own bonding agent, the compomer offers a simple and relatively rapid technique. The learning objective of this paper is to describe the utilization of the new restorative material in conjunction with a bonding agent to restore conservative cavity preparations in primary molars. Two clinical cases are used to illustrate the presentation.

  12. Materials for chairside CAD/CAM restorations.

    Science.gov (United States)

    Fasbinder, Dennis J

    2010-01-01

    Chairside computer-aided design/computer-aided manufacturing (CAD/CAM) systems have become considerably more accurate, efficient, and prevalent as the technology has evolved in the past 25 years. The initial restorative material option for chairside CAD/CAM restorations was limited to ceramic blocks. Restorative material options have multiplied and now include esthetic ceramics, high-strength ceramics, and composite materials for both definitive and temporary restoration applications. This article will review current materials available for chairside CAD/CAM restorations.

  13. Radiopacity of restorative composites by conventional radiography and digital images with different resolutions

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Raquel Venancio; Samento, Hugo Ramalho [Graduate Program in Dentistry, Federal University of Pelotas, Pelotas (Brazil); Duarte, Rosangela Marques; Raso, Sonia Saeger Meireles Monte; De Andrade Ana Karina Maciel; Anjos-Pontual Maria Luiza Dos [Dept. of Operative Dentistry, Federal University of Paraiba, Pelotas (Brazil)

    2013-09-15

    This study was performed to evaluate and compare the radiopacity of dentin, enamel, and 8 restorative composites on conventional radiograph and digital images with different resolutions. Specimens were fabricated from 8 materials and human molars were longitudinally sectioned 1.0 mm thick to include both enamel and dentin. The specimens and tooth sections were imaged by conventional radiograph using 4 sized intraoral film and digital images were taken in high speed and high resolution modes using a phosphor storage plate. Densitometric evaluation of the enamel, dentin, restorative materials, a lead sheet, and an aluminum step wedge was performed on the radiographic images. For the evaluation, the Al equivalent (mm) for each material was calculated. The data were analyzed using one-way ANOVA and Tukey's test (p<0.05), considering the material factor and then the radiographic method factor, individually. The high speed mode allowed the highest radiopacity, while the high resolution mode generated the lowest values. Furthermore, the high resolution mode was the most efficient method for radiographic differentiation between restorative composites and dentin. The conventional radiograph was the most effective in enabling differentiation between enamel and composites. The high speed mode was the least effective in enabling radiographic differentiation between the dental tissues and restorative composites. The high speed mode of digital imaging was not effective for differentiation between enamel and composites. This made it less effective than the high resolution mode and conventional radiographs. All of the composites evaluated showed radiopacity values that fit the ISO 4049 recommendations.

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

    DEFF Research Database (Denmark)

    van Dijken, Jan Wv; Pallesen, Ulla

    2014-01-01

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

  15. Radiopacity of restorative materials using digital images.

    Science.gov (United States)

    Salzedas, Leda Maria Pescinini; Louzada, Mário Jefferson Quirino; de Oliveira Filho, Antonio Braz

    2006-04-01

    The radiopacity of esthetic restorative materials has been established as an important requirement, improving the radiographic diagnosis. The aim of this study was to evaluate the radiopacity of six restorative materials using a direct digital image system, comparing them to the dental tissues (enamel-dentin), expressed as equivalent thickness of aluminum (millimeters of aluminum). Five specimens of each material were made. Three 2-mm thick longitudinal sections were cut from an intact extracted permanent molar tooth (including enamel and dentin). An aluminum step wedge with 9 steps was used. The samples of different materials were placed on a phosphor plate together with a tooth section, aluminum step wedge and metal code letter, and were exposed using a dental x-ray unit. Five measurements of radiographic density were obtained from each image of each item assessed (restorative material, enamel, dentin, each step of the aluminum step wedge) and the mean of these values was calculated. Radiopacity values were subsequently calculated as equivalents of aluminum thickness. Analysis of variance (ANOVA) indicated significant differences in radiopacity values among the materials (Pcomposite restorations it is important that the restorative material to be used has enough radiopacity, in order to be easily distinguished from the tooth structure in the radiographic image. Knowledge on the radiopacity of different materials helps professionals to select the most suitable material, along with other properties such as biocompatibility, adhesion and esthetic.

  16. New direct restorative materials. FDI Commission Project.

    Science.gov (United States)

    Hickel, R; Dasch, W; Janda, R; Tyas, M; Anusavice, K

    1998-02-01

    People worldwide have become increasingly aware of the potential adverse effects on the environment, of pollution control and of toxic effects of food, drugs and biomaterials. Amalgam and its potential toxic side effects (still scientifically unproven) continue to be discussed with increasing controversy by the media in some countries. Consequently, new direct restorative materials are now being explored by dentists, materials scientists and patients who are searching for the so-called 'amalgam substitute' or 'amalgam alternative'. From a critical point of view some of the new direct restorative materials are good with respect to aesthetics, but all material characteristics must be considered, such as mechanical properties, biological effects, and longterm clinical behaviour.

  17. What constitutes an ideal dental restorative material?

    Science.gov (United States)

    Rekow, E D; Bayne, S C; Carvalho, R M; Steele, J G

    2013-11-01

    Intense environmental concerns recently have prompted dentistry to evaluate the performance and environmental impact of existing restoration materials. Doing so entices us to explore the 'what if?' innovation in materials science to create more ideal restorative materials. Articulating a specification for our design and evaluation methods is proving to be more complicated than originally anticipated. Challenges exist not only in specifying how the material should be manipulated and perform clinically but also in understanding and incorporating implications of the skill of the operator placing the restoration, economic considerations, expectations patients have for their investment, cost-effectiveness, influences of the health care system on how and for whom restorations are to be placed, and global challenges that limit the types of materials available in different areas of the world. The quandary is to find ways to actively engage multiple stakeholders to agree on priorities and future actions to focus future directions on the creation of more ideal restorative materials that can be available throughout the world.

  18. [Dental restoration materials in pediatric dentistry].

    Science.gov (United States)

    Davidson, C L

    1997-02-01

    Restorative materials in pediatric dentistry have to fulfill special requirements. They should be easy to handle and applicable in a not always dry mouth. They should potentially be adhesive in order to avoid too much mechanical preparation. They do not have to be extremely wear resistant as the dwell time of the restorations is relatively short. Glass-ionomer cements and in particular the resin modified types possess properties which make them almost ideal for the required purpose.

  19. Directly Placed Restorative Materials: Review and Network Meta-analysis.

    Science.gov (United States)

    Schwendicke, F; Göstemeyer, G; Blunck, U; Paris, S; Hsu, L-Y; Tu, Y-K

    2016-06-01

    For restoring cavitated dental lesions, whether carious or not, a large number of material combinations are available. We aimed to systematically review and synthesize data of comparative dental restorative trials. A systematic review was performed. Randomized controlled trials published between 2005 and 2015 were included that compared the survival of ≥2 restorative and/or adhesive materials (i.e., no need for restorative reintervention). Pairwise and Bayesian network meta-analyses were performed, with separate evaluations for cervical cavitated lesions and load-bearing posterior cavitated lesions in permanent and primary teeth. A total of 11,070 restorations (5,330 cervical, 5,740 load bearing) had been placed in 3,633 patients in the included trials. Thirty-six trials investigated restoration of cervical lesions (all in permanent teeth) and 36 of load-bearing lesions (8 in primary and 28 in permanent teeth). Resin-modified glass ionomer cements had the highest chance of survival in cervical cavitated lesions; composites or compomers placed via 2-step self-etch and 3-step etch-and-rinse adhesives were ranked next. Restorations placed with 2-step etch-and-rinse or 1-step self-etch adhesives performed worst. For load-bearing restorations, conventional composites had the highest probability of survival, while siloranes were found least suitable. Ambiguity remains regarding which adhesive strategy to use in load-bearing cavitated lesions. Most studies showed high risk of bias, and several comparisons were prone for publication bias. If prioritized for survival, resin-modified glass ionomer cements might be recommended to restore cervical lesions. For load-bearing ones, conventional or bulk fill composites seem most suitable. The available evidence is quantitatively and qualitatively insufficient for further recommendations, especially with regard to adhesive strategies in posterior load-bearing situations. Moreover, different material classifications might yield

  20. Microleakage of Composite Restorations Following Chemo-mechanical and Conventional Caries Removal

    Directory of Open Access Journals (Sweden)

    SM. Mousavinenasab

    2004-12-01

    Full Text Available Statement of Problem: Microleakage is the most important factor in composite restorations failure, resulting in marginal degradation, marginal staining, secondary caries and pulp damage. One of the factors that influence microleakage is the method of cariesremoval. Convention rotary instrumentation generates smear layer on the dental surface,whereas chemo -mechanical caries removal increases surface roughness.Purpose: The aim of this study was to compare the microleakage of composite restorations following caries removal via conventional versus chemo -mechanical methods.Materials and Methods : One hundred class V carious human posterior teeth were randomly divided into two equal groups. Caries were completely removed with carbide burs in group one and according to manufacturer's instruction in chemo -mechanical group (Carisolv group or group two. Then the same composite restorative material, followed by finishing and polishing, filled all the cavities. Subsequently the specimens were thermocycled and then placed in dye solution. The teeth were sectioned through the restorations and evaluated for microleakage scores using a stereomicroscope. The data were analyzed using Mann-Whitney-U test.Results: Prevalence of scores 0 and 1 of microleakage in occlusal margins in group one was 80% and 20%, respectively and in group two 74% and 36%, respectively. Prevalence of scores 0, 1 and 2 of microleakage in gingival margins in group one was 56%, 36% and8%, respectively and 42%, 42% and 16% in group two, respectively. Scores 3 and 4 of microleakage were not seen in any of the groups. Statistical analysis showed significant difference in microleakage between occlusal and gingival margins in each group (P0.05.Conclusion: The results from this study indicate no significant difference in microleakage between conventional and chemo -mechanical caries removal methods.

  1. Comparative Evaluation of Microleakage in Conventional and RMGIC Restorations following Conventional and Chemomechanical Caries Removal: An in vitro Study.

    Science.gov (United States)

    Pavuluri, Chaitanya; Nuvvula, Sivakumar; Kamatham, Rekha Lakshmi; Nirmala, Svsg

    2014-01-01

    Conventional caries removal involves use of high-speed handpiece. Current concepts of caries excavation in cavitated lesions consist of manual excavators. Principles of minimal invasive approach indicate the need to excavate only carious tissue. The aim of this study was to compare the microleakage in conventional and resin modified glass ionomer cement restorations following conventional and chemomechanical caries removal. Hundred class I carious human mandibular first molar s were collected and divided into two groups: I and II (50 each). Each group was further divided into subgroups, i.e. (IA, IB and IIA, IIB). Caries was completely removed using conventional method in group one and chemomechanically in group two. The teeth in group IA, IIA are restored with conventional glass ionomer comment (GIC) and in group IB, IIB restored with resign-modified glass ionomer comments (RMGIC), followed by fnishing and polishing. Subsequently, the specimens were thermocycled and then placed in dye solution. The teeth were sectioned through the restorations and evaluated for microleakage scores using a stereomicroscope. The data were analyzed using Mann-Whitney U-test. Statistical analysis showed no significant difference in microleakage between the conventional GIC and RMGIC following conventional and chemomechanical caries removal method. Carisolv is minimally invasive and an effective alternative treatment for the removal of occlusal caries. How to cite this article: Pavuluri C, Nuvvula S, Kamatham RL, Nirmala SVSG. Comparative Evaluation of Microleakage in Conventional and RMGIC Restorations following Conventional and Chemomechanical Caries Removal: An in vitro Study. Int J Clin Pediatr Dent 2014;7(3):172-175.

  2. Selection of direct restorative and rooting filling materials by Kenyan ...

    African Journals Online (AJOL)

    Selection of direct restorative and rooting filling materials by Kenyan dentists in 2014. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... To establish the categories of direct restorative and root filling materials used by ...

  3. One year survival of ART and conventional restorations in patients with disability

    OpenAIRE

    Molina, G.F.; Faulks, D.; Mazzola, I.; Mulder, J.; Frencken, J.E.F.M.

    2014-01-01

    BACKGROUND: Providing restorative treatment for persons with disability may be challenging and has been related to the patient's ability to cope with the anxiety engendered by treatment and to cooperate fully with the demands of the clinical situation. The aim of the present study was to assess the survival rate of ART restorations compared to conventional restorations in people with disability referred for special care dentistry. METHODS: Three treatment protocols were distinguished: ART (ha...

  4. 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.

  5. The Effect of Lucite Glass Reinforcement on the Properties of Conventional Glass-Ionomer Filling Materials

    OpenAIRE

    Haleh Kazemi Yazdi; Richard van Noort; Mona Mansouri

    2016-01-01

    Statement of the Problem: The usage of glass ionomer cements (GICs) restorative materials are very limited due to lack of flexural strength and toughness. Purpose: The aim of this study was to investigate the effect of using a leucite glass on a range of mechanical and optical properties of commercially available conventional glass ionomer cement. Materials and Method: Ball milled 45μm leucite glass particles were incorporated into commercial conventional GIC, Ketac-Molar Easymix (KMEm...

  6. Color stability of esthetic restorative material after topical fluoride application

    OpenAIRE

    2015-01-01

    AIM: Present study was conducted to compare the effect of topical fluoride agents on color change of three aesthetic restorative materials. MATERIAL AND METHODS: Restorative material used were Ketac Fill type II (GIC), Filtek Z350(Composite) and Beuttifull II (Giomer). Topical Fluorides used were Pascal (1.23% APF gel) and Fluoride Varnish (Bifluoride). 24 samples of each restorative material were prepared, which were divided into 8 each, among three groups. Treatment of Group A with APF gel,...

  7. Class III Restoration of Anterior Primary Teeth: In Vitro Retention Comparison of Conventional, Modified and Air-abrasion Treated Preparations

    Directory of Open Access Journals (Sweden)

    Naser Asl Aminabadi

    2014-06-01

    Full Text Available Background and aims. Anterior esthetic restoration is challenging in pediatric dentistry, due to limited durability and poor retention of the restoration.This study assessed the effect of air abrasion on tensile failure load of composite class III restorations using different preparation techniques. Materials and methods. 100 extracted human anterior primary teeth were divided, based on the preparation methods, into four groups each consisting of 25 subjects : conventional (A, labial surface bevel (B, conventional + air abrasion (C, and labial surface bevel + air abrasion (D. After restoring cavities, tensile failure load of samples was measured in Newton by Universal testing machine at a crosshead speed of 1 mm per minute. The data were analyzed by Kruskal-Wallis and Mann Whitney U tests using SPSS software. Results. There were statistically significant differences between groups A and C (P = 0.003, groups A and B (P < 0.001, groups A and D (P < 0.001, groups B and C (P = 0.028, groups B and D (P = 0.027, and also groups C and D (P < 0.001. Group D demonstrated the highest mean tensile failure load. Conclusion. Labial surface bevel treated by air abrasion showed significantly more retention of composite restoration.

  8. Class III Restoration of Anterior Primary Teeth: In Vitro Retention Comparison of Conventional, Modified and Air-abrasion Treated Preparations.

    Science.gov (United States)

    Asl Aminabadi, Naser; Najafpour, Ebrahim; Erfanparast, Leila; Samiei, Mohammad; Haghifar, Monireh; Sighari Deljavan, Alireza; Jamali, Zahra; Pournaghi Azar, Fatemeh; Shokravi, Marzieh

    2014-01-01

    Background and aims. Anterior esthetic restoration is challenging in pediatric dentistry, due to limited durability and poor retention of the restoration.This study assessed the effect of air abrasion on tensile failure load of composite class III restorations using different preparation techniques. Materials and methods. 100 extracted human anterior primary teeth were divided, based on the preparation methods, into four groups each consisting of 25 subjects : conventional (A), labial surface bevel (B), conventional + air abrasion (C), and labial surface bevel + air abrasion (D). After restoring cavities, tensile failure load of samples was measured in Newton by Universal testing machine at a crosshead speed of 1 mm per minute. The data were analyzed by Kruskal-Wallis and Mann Whitney U tests using SPSS software. Results. There were statistically significant differences between groups A and C (P = 0.003), groups A and B (P & 0.001), groups A and D (P & 0.001), groups B and C (P = 0.028), groups B and D (P = 0.027), and also groups C and D (P& 0.001). Group D demonstrated the highest mean tensile failure load. Conclusion. Labial surface bevel treated by air abrasion showed significantly more retention of composite restoration.

  9. Microleakage evaluation of class V restorations with conventional and resin-modified glass ionomer cements.

    Science.gov (United States)

    Pontes, Danielson Guedes; Guedes-Neto, Manoel Valcacio; Cabral, Maria Fernanda Costa; Cohen-Carneiro, Flávia

    2014-09-01

    The aim of this study was to evaluate in vitro the marginal microleakage of conventional Glass Ionomer Cements (GIC) and Resin Modified Glass Ionomer Cements (RMGIC). The tested materials were grouped as follows: GIC category - G1 (Vidrion R - SSWhite); G2 (Vitro Fill - DFL); G3 (Vitro Molar - DFL); G4 (Bioglass R - Biodinâmica); and G5 (Ketac Fill - 3M/ESPE); and RMGIC category - G6 (Vitremer - 3M/ESPE); G7 (Vitro Fill LC - DFL); and G8 (Resiglass - Biodinâmica). Therefore, 80 class V cavities (2.0X2.0 mm) were prepared in bovine incisors, either in the buccal face. The samples were randomly divided into 8 groups and restored using each material tested according to the manufacturer. The root apices were then sealed with acrylic resin. The teeth were stored for 24 h in 100% humidity at 37°C. After storage, the specimens were polished with extra-slim burs and silicon disc (Soft-lex - 3M/ESPE), then were isolated with cosmetic nail polish up to 1 mm around the restoration. Then, the samples were immersed in 50% AgNO3 solution for 12 h and in a developing solution for 30 min. They were rinsed and buccal-lingual sectioned. The evaluation of the microleakage followed scores from 0 to 3. The Kruskal-Wallis test and Dunn method test were applied (a=0.05). The results showed that there was no difference between the enamel and dentin margins. However, GIC materials presented more microleakage than RMGIC.

  10. Polymerization shrinkage of flowable resin-based restorative materials

    OpenAIRE

    Stavridakis, Minos M; Dietschi, Didier; Krejci, Ivo

    2005-01-01

    This study measured the linear polymerization displacement and polymerization forces induced by polymerization shrinkage of a series of flowable resin-based restorative materials. The materials tested were 22 flowable resin-based restorative materials (Admira Flow, Aelite Flow, Aeliteflow LV, Aria, Crystal Essence, Definite Flow, Dyract Flow, Filtek Flow, FloRestore, Flow-it, Flow-Line, Freedom, Glacier, OmegaFlo, PermaFlo, Photo SC, Revolution 2, Star Flow, Synergy Flow, Tetric Flow, Ultrase...

  11. Marginal adaptation and performance of bioactive dental restorative materials in deciduous and young permanent teeth.

    OpenAIRE

    Elizabeta Gjorgievska; John W. Nicholson; Snezana Iljovska; Slipper, Ian J.

    2008-01-01

    Objective: The aim of this study was to investigate the adaptation of different types of restorations towards deciduous and young permanent teeth. Materials and Methods: Class V cavities were prepared in deciduous and young permanent teeth and filled with different materials (a conventional glass-ionomer, a resin-modified glass-ionomer, a poly-acid-modified composite resin and a conventional composite resin). Specimens were aged in artificial saliva for 1, 6, 12 and 18 months, then examined b...

  12. Monitoring the restoration of interfacial contact for self healing thermal interface materials for LED and microelectronic applications

    NARCIS (Netherlands)

    Lafont, U.L.; Van Zeijl, H.W.; Van der Zwaag, S.

    2013-01-01

    While conventional self healing materials focus on the restoration of mechanical properties, newer generations of self healing materials focus on the restoration of other functional (i.e. non-mechanical) properties. Thermal conductivity is an example of an important functional property of a Thermal

  13. [Wear and different restorative materials--a review].

    Science.gov (United States)

    Beyth, N; Sharon, E; Lipovetsky, M; Smidt, A

    2006-07-01

    Wear of materials is a complex and unpredictable phenomenon. The variables affecting the mechanism of wear include the properties of the two contacting materials and the surrounding and interfacial media. This paper reviews the dental wear of different restorative materials and their counter effect on the tooth structure. It presents the updated classifications for tooth surface lesions termed dental wear, and discusses the wear behavior of various restorative materials. Some guidelines for restorative material selection are given. Clinical wear bears a multifactorial etiology, understanding the mechanism of action is an important step in an appropriate restoration material selection. Each material selected should meet the individual wear behavior and needs. Individual factors may enhance the wear rates: aggressive tooth brushing, parafunctions, diet, acidic/aqueous environment, surface geometry, and diminished tooth support. Supportive treatment following restoration is important to monitor wear rates.

  14. Adhesive Restorative Materials in the Pediatric Dentistry: Review of Literature

    Directory of Open Access Journals (Sweden)

    Márcia Pereira Alves dos SANTOS

    2006-04-01

    Full Text Available Introduction: A range of direct adhesive restorative materials are available in the market and can be used for filling primary molars by Pediatric Dentistry. Objective: The aim of this study was to review in the dental literature the main properties of many direct resin based restorative materials and associates them with their clinical performance, in order to better understand their clinical behaviour. Conclusion: Considering this review of dental literature, the selection of direct adhesive restorative materials should based on the knowledge of them, in order to improve the life span of these restorations.

  15. Material and clinical considerations for full-coverage indirect restorations.

    Science.gov (United States)

    Martin, Margaret P

    2012-11-01

    Because dental ceramics have been used for decades and continuously improved over the years, there is a plethora of information regarding their material characteristics, applications, and contraindications. Each restorative ceramic material demonstrates benefits and disadvantages, making it difficult for dentists to research, retain, and apply the ideal material for individual restorations and/or combination cases. This article outlines the applications and benefits of dental ceramics in general and examines and reviews the current ceramic alternatives available for restorative dentistry today. It also discusses the material composition and properties of a recently introduced new classification of indirect material: resin nano-ceramic.

  16. Various Effects of Sandblasting of Dental Restorative Materials.

    Directory of Open Access Journals (Sweden)

    Goro Nishigawa

    Full Text Available Sandblasting particles which remain on the surfaces of dental restorations are removed prior to cementation. It is probable that adhesive strength between luting material and sandblasting particle remnants might exceed that with restorative material. If that being the case, blasting particles adhere to sandblasted material surface could be instrumental to increasing adhesive strength like underlying bonding mechanism between luting material and silanized particles of tribochemical silica coating-treated surface. We hypothesize that ultrasonic cleaning of bonding surfaces, which were pretreated with sandblasting, may affect adhesive strength of a resin luting material to dental restorative materials.We therefore observed adhesive strength of resin luting material to aluminum oxide was greater than those to zirconia ceramic and cobalt-chromium alloy beforehand. To measure the shear bond strengths of resin luting material to zirconia ceramic and cobalt-chromium alloy, forty specimens of each restorative material were prepared. Bonding surfaces were polished with silicon abrasive paper and then treated with sandblasting. For each restorative material, 40 sandblasted specimens were equally divided into two groups: ultrasonic cleaning (USC group and non-ultrasonic cleaning (NUSC group. After resin luting material was polymerized on bonding surface, shear test was performed to evaluate effect of ultrasonic cleaning of bonding surfaces pretreated with sandblasting on bond strength.For both zirconia ceramic and cobalt-chromium alloy, NUSC group showed significantly higher shear bond strength than USC group.Ultrasonic cleaning of dental restorations after sandblasting should be avoided to retain improved bonding between these materials.

  17. Compressive fatigue limit of four types of dental restorative materials.

    Science.gov (United States)

    Chen, Song; Öhman, Caroline; Jefferies, Steven R; Gray, Holly; Xia, Wei; Engqvist, Håkan

    2016-08-01

    The purpose of this study was to evaluate the quasi-static compressive strength and the compressive fatigue limit of four different dental restorative materials, before and after aging in distilled water for 30 days. A conventional glass ionomer cement (Fuji IX GP; IG), a zinc-reinforced glass ionomer cement (Chemfil rock; CF), a light curable resin-reinforced glass ionomer cement (Fuji II LC; LC) and a resin-based composite (Quixfil; QF) were investigated. Cylindrical specimens (4mm in diameter and 6mm in height) were prepared according to the manufacturer׳s instructions. The compressive fatigue limit was obtained using the staircase method. Samples were tested in distilled water at 37°C, at a frequency of 10Hz with 10(5) cycles set as run-out. 17 fatigue samples were tested for each group. Two-way ANOVA and one-way ANOVA followed by Tukey׳s post-hoc test were used to analyze the results. Among the four types of materials, the resin-based composite exhibited the highest compressive strength (244±13.0MPa) and compressive fatigue limit (134±7.8MPa), followed by the light-cured resin reinforced glass ionomer cement (168±8.5MPa and 92±6.6MPa, respectively) after one day of storage in distilled water. After being stored for 30 days, all specimens showed an increase in compressive strength. Aging showed no effect on the compressive fatigue limit of the resin-based composite and the light-cured resin reinforced glass ionomer cement, however, the conventional glass ionomer cements showed a drastic decrease (37% for IG, 31% for CF) in compressive fatigue limit. In conclusion, in the present study, resin modified GIC and resin-based composite were found to have superior mechanical properties to conventional GIC.

  18. Recent advances and developments in composite dental restorative materials.

    Science.gov (United States)

    Cramer, N B; Stansbury, J W; Bowman, C N

    2011-04-01

    Composite dental restorations represent a unique class of biomaterials with severe restrictions on biocompatibility, curing behavior, esthetics, and ultimate material properties. These materials are presently limited by shrinkage and polymerization-induced shrinkage stress, limited toughness, the presence of unreacted monomer that remains following the polymerization, and several other factors. Fortunately, these materials have been the focus of a great deal of research in recent years with the goal of improving restoration performance by changing the initiation system, monomers, and fillers and their coupling agents, and by developing novel polymerization strategies. Here, we review the general characteristics of the polymerization reaction and recent approaches that have been taken to improve composite restorative performance.

  19. Comparative Analysis of Effects of Oral Restoration Between Zirconium, Titanium Niobium Tin Alloy and Conventional Repair Material%新型口腔修复用钛锆铌锡合金和常规修复材料在口腔修复中的效果对比分析

    Institute of Scientific and Technical Information of China (English)

    王晓静

    2015-01-01

    Objective Comparative analysis of new type dental restorations with zirconium titanium niobium tin alloy and conventional repair materials in oral cavity repair. Methods Selected 50 cases of patients in our hospital with oral health problems as the research object, according to the digital method divided them into control group and observation group, 25 cases in each group, compared the repair effect and oral conditions. Results Observation group were significantly better than the control group, there was statistically signiifcant difference (P<0.05). Conclusion The effect of new dental restorations with zirconium titanium niobium tin alloy repair material is remarkable, safe and reliable.%目的:对比分析新型口腔修复用钛锆铌锡合金和常规修复材料在口腔修复中的效果。方法选取我院收治的50例口腔问题患者作为研究对象,按照数字法分为对照组(常规材料)和观察组(钛锆铌锡合金材料),每组25例,对比两组患者修复情况和口腔情况。结果观察组患者的口腔情况以及修复体情况均优于对照组,差异具有统计学意义(P<0.05)。结论新型口腔修复用钛锆铌锡合金修复材料效果显著,安全可靠。

  20. Material choice for restorative dentistry: inlays, onlays, crowns, and bridges.

    Science.gov (United States)

    Small, Bruce W

    2006-01-01

    New materials--specifically the new CAD/CAM zirconia-based systems--are available now for restorative dentistry. When esthetics are not a factor, gold remains the standard, particularly for intracoronal restorations and full posterior coverage. Tooth-colored crowns made with zirconia are new and offer great promise for the future, although more long-term in vivo studies are necessary.

  1. Fracture Resistance of Endodontically Treated Teeth Restored With Bulk Fill, Bulk Fill Flowable, Fiber-reinforced, and Conventional Resin Composite.

    Science.gov (United States)

    Atalay, C; Yazici, A R; Horuztepe, A; Nagas, E; Ertan, A; Ozgunaltay, G

    2016-01-01

    The aim of this in vitro study was to evaluate the fracture resistance of endodontically treated teeth restored with different types of restorative resins. Seventy-two sound maxillary premolar teeth were randomly divided into six groups (n=12). The teeth in the first group were left intact and tested as unprepared negative control (group I) specimens. The teeth in the remaining five groups were prepared with MOD cavities and endodontically treated. The teeth in one of the five groups (positive control group II) were unrestored. The rest of the prepared cavities were restored as follows: group III: bulk fill resin composite/Filtek Bulk Fill (3M ESPE); group IV: bulk fill flowable resin composite + nanohybrid/SureFil SDR Flow + Ceram.X Mono (Dentsply); group V: fiber-reinforced composite + posterior resin composite/GC everX posterior + G-aenial posterior (GC Corp.); and group VI: nanohybrid resin composite/Tetric N-Ceram (Ivoclar/Vivadent). Each restorative material was used with its respective adhesive system. The restored teeth were stored in distilled water for 24 hours at 37°C and were then thermocycled (5-55°C, 1000×). Specimens were subjected to a compressive load until fracture at a crosshead speed of 0.5 mm/min. The data were analyzed using one-way analysis of variance followed by the post hoc Tukey honestly significantly different test (p0.05). The lowest values were obtained in the positive control group (group II); these values were significantly lower than those of the other groups (pcomposite were not different from those restored with conventional nanohybrid resin composite.

  2. Restoration of digital images with known space-variant blurs from conventional optical systems

    Science.gov (United States)

    Costello, Thomas P.; Mikhael, Wasfy B.

    1999-07-01

    Space-variant (SV) digital image restoration methods attempt to restore images degraded by blurs that vary over the image field. One specific source of SV blurs is that of geometrical optical aberrations, which divert light rays as they pass through the optical system away from an ideal focal point. For simple optical system, aberrations can become significant even at moderate field angles. Restoration methods have been developed for some space- variant aberrations when they are individually dominant, but such dominance is not typically characteristic of conventional optical systems. In this paper, an iterative method of restoration that is applicable to generalized, known space-variant blurs is applied to simulations of images generated with a spherical lines. The method is based on the Gauss-Seidel method of solution to systems of linear equations. The method is applied to sub-images having off- axis displacements of up to 453 pixels, and found to be superior in restoration effectiveness to Fourier methods in that range of field angles.

  3. In Vitro Fatigue Resistance of Teeth Restored With Bulk Fill versus Conventional Composite Resin.

    Science.gov (United States)

    Rauber, Gabrielle Branco; Bernardon, Jussara Karina; Vieira, Luiz Clovis Cardoso; Maia, Hamilton Pires; Horn, Françoá; Roesler, Carlos Rodrigo de Mello

    2016-01-01

    The aim of this study was to compare the fatigue resistance of restored teeth with bulk fill composite resin, conventional composite resin with incremental insertion and unprepared sound teeth. Twenty-eight extracted maxillary premolars were selected and divided into 4 groups based on composite resin and insertion technique: control (C), conventional composite resin with incremental insertion (I) and bulk fill composite resin with three (BF3) or single increment (BF1). The restored specimens were submitted to fatigue resistance test with a 5 Hz frequency. An initial application of 5,000 sinusoidal load cycles with a minimum force of 50 N and a maximum force of 200 N was used. Next, were applied stages of 30,000 load cycles with the maximum force increasing gradually: 400, 600, 800, 1000, 1200 and 1400 N. The test was concluded when 185,000 load cycles were achieved or the specimen failed. The fatigue resistance data were recorded for comparison, using the Kaplan-Meier survival curve and analyzed by log-rank test at 0.05 significance. Fractures were classified based on the position of the failure - above or below the cementoenamel junction (CEJ). Statistical analysis of the Kaplan-Meier survival curve and log-rank test showed a significant difference between groups (p=0.001). The fracture analysis demonstrated that only 28.58% of failures were below the CEJ in group C, while for groups I, BF1 and BF3 they were 42.85%, 85.71% and 85.71%, respectively. Teeth restored with composite bulk fill in both techniques present similar fatigue resistance values compared with those restored with a conventional incremental insertion of composite, while the fatigue strength values of unprepared sound teeth were higher. Furthermore, unprepared sound teeth showed a lower percentage of fractures below the CEJ.

  4. Comparison of Microleakage of Glass Ionomer Restoration in Primary Teeth Prepared by Er: YAG Laser and the Conventional Method

    Directory of Open Access Journals (Sweden)

    M. Ghandehari

    2012-01-01

    Full Text Available Objective: One of the main criteria in evaluating the restorative materials is the degree of microleakage. The aim of this study was to compare the microleakage of glass ionomer restored cavities prepared by Er:YAG laser or turbine and bur.Materials and Methods: Twenty extracted caries-free deciduous posterior teeth were selected for this study. The teeth were randomly divided into two groups for cavity preparation. Cavities in group one were prepared by high speed turbine and bur. In the second group, Er:YAG laser with a 3W output power, 300 mJ energy and 10 Hz frequency was used. Cavities were restored with GC Fuji II LC. After thermocycling, the samples were immersed into 0.5% methylene blue solution. They were sectioned for examination under optic microscope.Results: The Wilcoxon signed ranks test showed no significant difference between microleakage of the laser group and the conventional group (P>0.05.Conclusion: Er:YAG laser with its advantages in pediatric dentistry may be suggested as an alternative device for cavity preparation.Key Words: Er:YAG laser, Glass ionomer, Microleakage

  5. Nanotechnology-based restorative materials for dental caries management.

    Science.gov (United States)

    Melo, Mary A S; Guedes, Sarah F F; Xu, Hockin H K; Rodrigues, Lidiany K A

    2013-08-01

    Nanotechnology has been applied to dental materials as an innovative concept for the development of materials with better properties and anticaries potential. In this review we discuss the current progress and future applications of functional nanoparticles incorporated in dental restorative materials as useful strategies to dental caries management. We also overview proposed antimicrobial and remineralizing mechanisms. Nanomaterials have great potential to decrease biofilm accumulation, inhibit the demineralization process, to be used for remineralizing tooth structure, and to combat caries-related bacteria. These results are encouraging and open the doors to future clinical studies that will allow the therapeutic value of nanotechnology-based restorative materials to be established.

  6. Susceptibility of green and conventional building materials to microbial growth.

    Science.gov (United States)

    Mensah-Attipoe, J; Reponen, T; Salmela, A; Veijalainen, A-M; Pasanen, P

    2015-06-01

    Green building materials are becoming more popular. However, little is known about their ability to support or limit microbial growth. The growth of fungi was evaluated on five building materials. Two green, two conventional building materials and wood as a positive control were selected. The materials were inoculated with Aspergillus versicolor, Cladosporium cladosporioides and Penicillium brevicompactum, in the absence and presence of house dust. Microbial growth was assessed at four different time points by cultivation and determining fungal biomass using the N-acetylhexosaminidase (NAHA) enzyme assay. No clear differences were seen between green and conventional building materials in their susceptibility to support microbial growth. The presence of dust, an external source of nutrients, promoted growth of all the fungal species similarly on green and conventional materials. The results also showed a correlation coefficient ranging from 0.81 to 0.88 between NAHA activity and culturable counts. The results suggest that the growth of microbes on a material surface depends on the availability of organic matter rather than the classification of the material as green or conventional. NAHA activity and culturability correlated well indicating that the two methods used in the experiments gave similar trends for the growth of fungi on material surfaces.

  7. Interpreting finite element results for brittle materials in endodontic restorations.

    Science.gov (United States)

    Pérez-González, Antonio; Iserte-Vilar, José L; González-Lluch, Carmen

    2011-06-02

    Finite element simulation has been used in last years for analysing the biomechanical performance of post-core restorations in endodontics, but results of these simulations have been interpreted in most of the works using von Mises stress criterion. However, the validity of this failure criterion for brittle materials, which are present in these restorations, is questionable. The objective of the paper is to analyse how finite element results for brittle materials of endodontic restorations should be interpreted to obtain correct conclusions about the possible failure in the restoration. Different failure criteria (Von Mises, Rankine, Coulomb-Mohr, Modified Mohr and Christensen) and material strength data (diametral tensile strength and flexural strength) were considered in the study. Three finite element models (FEM) were developed to simulate an endodontic restoration and two typical material tests: diametral tensile test and flexural test. Results showed that the Christensen criterion predicts similar results as the Von Mises criterion for ductile components, while it predicts similar results to all other criteria for brittle components. The different criteria predict different failure points for the diametral tensile test, all of them under multi-axial stress states. All criteria except Von Mises predict failure for flexural test at the same point of the specimen, with this point under uniaxial tensile stress. From the results it is concluded that the Christensen criterion is recommended for FEM result interpretation in endodontic restorations and that the flexural test is recommended to estimate tensile strength instead of the diametral tensile test.

  8. A plastic micropump constructed with conventional techniques and materials

    NARCIS (Netherlands)

    Bohm, Sebastian; Olthuis, Wouter; Bergveld, P.

    1999-01-01

    A plastic micropump which can be produced using conventional production techniques and materials is presented. By applying well-known techniques and materials, economic fabrication of micropumps for various applications is feasible even at low production volumes. The micropump is capable of pumping

  9. Degradation of Resin Restorative Materials by Streptococcus Mutans: A Pilot Study.

    Science.gov (United States)

    Gautam, Ankit K; Thakur, Ruchi; Shashikiran, N D; Shilpy, Singla; Agarwal, Nikita; Tiwari, Shilpi

    To evaluate the degradation of three resin based restorative materials by S Mutans. Class I cavity was prepared in extracted premolars and were randomly divided into 3 groups (Group I - Conventional composite (CC), Group II - Resin Modified GIC and Group III-Giomer). Teeth were then restored by respective restorative material and equally divided in two subgroups (Control and Experimental). Experiment subgroup samples were then incubated in 2 ml of BHI with 1:10 dilution of SM (MTCC-497) grown overnight in BHI whereas control subgroup samples were incubated in BHI without SM. The incubation solution was collected at 2,14 and 30 days interval, and the analysis for identification and quantification of Bis-HPPP was done by High performance Liquid Chromatography. Statistical analysis of the collected data revealed a statistically increased Bis HPPP production in the presence of SM in all the tested materials, with minimum in Resin Modified GIC and a maximum in Conventional Composite (CC). SM degrades the resin based restorative materials & among the tested materials Resin Modified GIC appears to be most Biostable.

  10. Effect of two restorative materials on root dentine erosion.

    Science.gov (United States)

    Domiciano, Silvia Jorge; Colucci, Vivian; Serra, Mônica Campos

    2010-05-01

    This study sought to evaluate the microhardness of root dentine adjacent to glass-ionomer and composite resin restorations after erosive challenge. A crossover study was performed in two phases of 4 consecutive days each. One hundred twelve bovine root dentine slabs were obtained, and standardized box-shaped cavities were prepared at center of each specimen. The prepared cavities were randomly restored with glass-ionomer cement or composite resin. The slabs were randomly assigned among 14 volunteers, which wore intraoral palatal device containing four restored root dentin slabs. Starting on the second day, half of the palatal acrylic devices were immersed extraorally in a lemonade-like carbonated soft drink for 90 s, four times daily for 3 days. After 3-day wash-out, dentine slabs restored with the alternative material were placed into palatal appliance and the volunteers started the second phase of this study. After erosive challenges, microhardness measurements were performed. Regardless of the restorative material employed, eroded specimens demonstrated lower microhardness value (p < 0.0001). At eroded condition examined in this study, dentine restored with glass-ionomer cement showed higher microhardness values (p < 0.0001). It may be concluded that the glass-ionomer cement decreases the progression of root dentine erosion at restoration margin. (c) 2010 Wiley Periodicals, Inc.

  11. 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.

  12. Influence of citric acid on the surface texture of glass ionomer restorative materials

    Directory of Open Access Journals (Sweden)

    Dappili SwamiRanga Reddy

    2014-01-01

    Full Text Available Aim: This study determined the effectiveness of G-coat plus surface protective agent over petroleum jelly on the surface texture of conventional Glass ionomer restorative materials. Materials and Methods: Three chemically cured conventional glass ionomer restorative materials type II, type IX and ketac molar were evaluated in this study. Sixty specimens were made for each restorative material. They were divided into two groups of thirty specimens each. Of the sixty specimens, thirty were coated with G-coat plus (a nano-filler coating and the rest with petroleum jelly. Thirty samples of both protective coating agents were randomly divided into six groups of five specimens and conditioned in citric acid solutions of differing pH (pH 2, 3, 4, 5, 6 & 7. Each specimen was kept in citric acid for three hours a day, and the rest of time stored in salivary substitute. This procedure was repeated for 8 days. After conditioning, the surface roughness (Ra, ΅m of each specimen was measured using a surface profilometer (Taylor & Habson, UK. Data was analyzed using one-way analysis of variance (ANOVA and Tukey′s HSD test at a significance level of 0.05. Results: The surface textures of all the tested glass ionomer restorative materials protected with G-coat plus were not significantly affected by acids at low pH. The surface textures of all the tested glass ionomer restorative materials protected with petroleum jelly coating were significantly affected by acids at low pH. Conclusion: The effects of pH on the surface texture of glass ionomer restoratives are material dependent. Among all the materials tested the surface texture of Type II GIC (Group I revealed marked deterioration when conditioned in solutions of low pH and was statistically significant. Hence, a protective coating either with G-coat plus or with light polymerized low viscosity unfilled resin adhesives is mandatory for all the glass ionomer restorations to increase the wear resistance of

  13. FEATURES OF RESTORATION OF DISPERSE POROUS MATERIALS

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2016-01-01

    Full Text Available The article presents the results of research recycling of dispersed materials in rotary furnaces. Has been received new data on the of heat and mass transfer processes and carry out intensive and continuous process of solid- liquid-phase reduction of oxides in a single unit.

  14. Finite element calculation of residual stress in dental restorative material

    Science.gov (United States)

    Grassia, Luigi; D'Amore, Alberto

    2012-07-01

    A finite element methodology for residual stresses calculation in dental restorative materials is proposed. The material under concern is a multifunctional methacrylate-based composite for dental restorations, activated by visible light. Reaction kinetics, curing shrinkage, and viscoelastic relaxation functions were required as input data on a structural finite element solver. Post cure effects were considered in order to quantify the residual stresses coming out from natural contraction with respect to those debited to the chemical shrinkage. The analysis showed for a given test case that residual stresses frozen in the dental restoration at uniform temperature of 37°C are of the same order of magnitude of the strength of the dental composite material per se.

  15. Influence of thermal stress on marginal integrity of restorative materials

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    Maximiliano Sérgio Cenci

    2008-04-01

    Full Text Available The aim of this study was to evaluate the influence of thermal stress on the marginal integrity of restorative materials with different adhesive and thermal properties. Three hundred and sixty Class V cavities were prepared in buccal and lingual surfaces of 180 bovine incisors. Cervical and incisal walls were located in dentin and enamel, respectively. Specimens were restored with resin composite (RC; glass ionomer (GI or amalgam (AM, and randomly assigned to 18 groups (n=20 according to the material, number of cycles (500 or 1,000 cycles and dwell time (30 s or 60 s. Dry and wet specimens served as controls Specimens were immersed in 1% basic fuchsine solution (24 h, sectioned, and microleakage was evaluated under x40 magnification. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests: Thermal cycling regimens increased leakage in all AM restorations (p<0.05 and its effect on RC and GI restorations was only significant when a 60-s dwell time was used (p<0.05. Marginal integrity was more affected in AM restorations under thermal cycling stress, whereas RC and GI ionomer restoration margins were only significantly affected only under longer dwell times.

  16. 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.

  17. Embryotoxicity assays for leached components from dental restorative materials

    OpenAIRE

    Mummolo Stefano; Tecco Simona; Gallusi Gianni; Farini Donatella; Klinger Francesca G; Marzo Giuseppe; Libonati Antonio; De Felici Massimo; Campanella Vincenzo

    2011-01-01

    Abstract Background Currently, there are no suitable assays available to evaluate the embryotoxicity of leached components from restorative dental materials. Methods The effect of the medium conditioned by composites and amalgam on mouse blastocysts in vitro was tested. The materials were also subcutaneously implanted, and the effect of the medium supplemented with serum from the host blood was evaluated in the embryotoxicity assay. The embryo implantation rate in the material-transplanted mo...

  18. Marginal adaptation and performance of bioactive dental restorative materials in deciduous and young permanent teeth

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    Elizabeta Gjorgievska

    2008-02-01

    Full Text Available OBJECTIVE: The aim of this study was to investigate the adaptation of different types of restorations towards deciduous and young permanent teeth. MATERIAL AND METHODS: Class V cavities were prepared in deciduous and young permanent teeth and filled with different materials (a conventional glass-ionomer, a resin-modified glass-ionomer, a poly-acid-modified composite resin and a conventional composite resin. Specimens were aged in artificial saliva for 1, 6, 12 and 18 months, then examined by SEM. RESULTS: The composite resin and the polyacid-modified composite had better marginal adaptation than the glass-ionomers, though microcracks developed in the enamel of the tooth. The glass-ionomers showed inferior marginal quality and durability, but no microcracking of the enamel. The margins of the resin-modified glass-ionomer were slightly superior to the conventional glass-ionomer. Conditioning improved the adaptation of the composite resin, but the type of tooth made little or no difference to the performance of the restorative material. All materials were associated with the formation of crystals in the gaps between the filling and the tooth; the quantity and shape of these crystals varied with the material. CONCLUSIONS: Resin-based materials are generally better at forming sound, durable margins in deciduous and young permanent teeth than cements, but are associated with microcracks in the enamel. All fluoride-releasing materials give rise to crystalline deposits.

  19. Human epithelial tissue culture study on restorative materials.

    Science.gov (United States)

    Forster, András; Ungvári, Krisztina; Györgyey, Ágnes; Kukovecz, Ákos; Turzó, Kinga; Nagy, Katalin

    2014-01-01

    Health condition of the gingival tissues contacting the surfaces of fixed prostheses is a result of multiple etiologic factors. The aim of the investigation discussed here was to evaluate the attachment and proliferation rate of cultured human epithelial cells on three commonly used restorative materials under in vitro conditions. Morphological and chemical structure of polished lithium-disilicate (IPS e.max Press, Ivoclar Vivadent AG, Germany), yttrium modified zirconium dioxide (5-TEC ICE Zirkon Translucent, Zirkonzahn GmbH Srl, Germany) and cobalt chromium alloy (Remanium star, Dentaurum GmbH & Co. KG, Germany) discs were examined by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM). Human epithelial cells harvested and cultured from one donor, were applied to investigate cell attachment (24h observation) and proliferation (72h observation) via dimethylthiazol-diphenyl tetrazolium bromide (MTT) and AlamarBlue(®) (AB) assays on control surface (cell-culture plate) and on the restorative materials (n=3×20 specimens/material). SEM and AFM revealed typical morphology and roughness features for the materials. Zirconia presented significantly higher Ra value. EDS confirmed typical elements on the investigated restorative materials: lithium-disilicate (Si, O); Zirconia (Zi, Y, O); CoCr (Co, Cr, W). All surfaces except CoCr exhibited significant cell proliferation according to MTT and AB assays after 72h compared to 24h. Among the restorative materials, CoCr samples showed the highest cell attachment as indicated by MTT assay. AB results showed that attachment and proliferation of human epithelial cells is supported more on lithium-disilicate. Both assays indicated the lowest value for zirconia. The results indicate that the restorative materials examined are equally suitable for subgingival restorations. Lithium-disilicate exhibited the best biocompatibility. The examined materials are indicated for use

  20. Impact of erosive conditions on tooth-colored restorative materials.

    Science.gov (United States)

    Attin, Thomas; Wegehaupt, Florian J

    2014-01-01

    To give an overview of the impact of erosive conditions on the behavior of tooth-colored restoratives and performance of dental adhesives. Acid-induced erosive lesions of enamel and dentin often need restorative procedures for rehabilitation. Nowadays, mostly tooth-colored restoratives (ceramics or resin composites), which are adhesively fixed to the dental substrate are used for this purpose. In some cases it might be necessary to seal the exposed dentin before achieving this goal in order to combat hypersensitivities and to protect those teeth from further erosive and abrasive loss. Moreover, it is conceivable that patients will fall back into their old "erosive behavior" after the application of restoratives. The following overview describes in how far intra-oral erosive conditions might affect the integrity of restorative materials, such as composite resins and ceramics, or of dentin sealants. Additionally, the use of erosively altered enamel and dentin as substrate for adhesive technologies is elucidated. In the literature, information of the behavior of tooth-colored restoratives under still persisting erosive conditions are limited and mostly based on in vitro-studies. There is information that the adhesion of dental adhesives to eroded dentin is compromised as compared to regular dentin. The impact of erosive conditions relevant for the oral cavity on ceramics and resin composites seems to be rather low, although only few clinical studies are available. The review showed that erosive conditions might have only little impact on behavior of tooth-colored restorative materials, such as composites and ceramics. Dentin sealants also seem to be rather resistant against erosive conditions and might therefore serve as an intermediary treatment option for exposed dentin surfaces. The adhesion of dentin adhesives to eroded dentin might be increased by mechanical pre-treatment of the substrate, but needs further investigation. Copyright © 2013 Academy of Dental

  1. Role of dental restoration materials in oral mucosal lichenoid lesions

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    Rajneesh Sharma

    2015-01-01

    Full Text Available Background: Dental restorative materials containing silver-mercury compounds have been known to induce oral lichenoid lesions. Objectives: To determine the frequency of contact allergy to dental restoration materials in patients with oral lichenoid lesions and to study the effect of removal of the materials on the lesions. Results: Forty-five patients were recruited in three groups of 15 each: Group A (lesions in close contact with dental materials, Group B (lesions extending 1 cm beyond the area of contact and Group C (no topographic relationship. Thirty controls were recruited in two groups of 15 individuals each: Group D (oral lichenoid lesions but no dental material and Group E (dental material but no oral lichenoid lesions. Patch tests were positive in 20 (44.5% patients. Mercury was the most common allergen to elicit a positive reaction in eight patients, followed by nickel (7, palladium (5, potassium dichromate (3, balsam of Peru, gold sodium thiosulphate 2 and tinuvin (2 and eugenol (1, cobalt chloride (1 and carvone (1. Seven patients elicited positive response to more than one allergen. In 13 of 20 patients who consented to removal of the dental material, complete healing was observed in 6 (30%, marked improvement in 7 (35% and no improvement in 7 (35% patients. Relief of symptoms was usually observed 3 months after removal. Limitations: Limited number of study subjects and short follow up after removal/replacement of dental restoration materials are the main limitations of this study. Conclusion: Contact allergy to amalgam is an important etiologic factor in oral lichenoid lesions and removal of restorative material should be offered to patients who have lesions in close proximity to the dental material.

  2. Shear bond strengths of self-adhesive luting resins fixing dentine to different restorative materials.

    Science.gov (United States)

    Zhang, Congxiao; Degrange, Michel

    2010-01-01

    The purpose of this study was to assess the bond strengths of three self-adhesive resin cements (Rely X Unicem, Maxcem and Multilink Sprint) fixing dentine to four different restorative substrates (Ni-Cr alloy, E-Max glass-ceramic, Y-TZP Zirconia and Adoro micro-filled composite) and to compare their performances with those of two conventional dual-cured luting cements (Variolink II + Total-etch Excite DSC and Multilink Automix + Self-etching Primer A + B). Cylindric specimens (5 x 5 mm) were prepared with the four restorative materials for bonding to human dentine. Three surface treatments were performed depending on the restorative material: (i) Al2O3 50 microm sandblasting (Ni-Cr, Adoro), (ii) #800 SiC polishing (Zirconia, E-Max), (iii) hydrofluoric acid (HF)-etching (E-Max). Twenty-five groups (n = 10) were designed according to luting cements, restorative materials and surface pre-treatments. In some experimental groups, Variolink II and Multilink Automix were coupled with, respectively, a silane primer (Monobond S) and an alloy/zirconia primer (Multilink A/Z primer). Specimens were stored in distilled water at 37 degrees C for 24 h and then loaded in shear until failure. Variolink II and Multilink Automix showed the highest bond strengths, regardless of the restorative substrate, when used with dentine bonding systems and primers, while the weakest bonds were with Maxcem. The bond strength recorded with the two other self-adhesive cements depended on the nature of the restorative substrate. Increasing retention at the interfaces (i.e., HF ceramic etching) and using specific primers significantly improves the bond strength of luted restorative materials to dentine.

  3. New materials for structural restoration: an old debate

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    Federica Ottoni

    2015-12-01

    Full Text Available The use of composites in architectural restoration is becoming more and more widespread, due to their technical advantages, in many cases. However, using these materials in the field of cultural heritage creates not only technical problems but also cultural issues. The paper deals with these issues, starting from some considerations on the use of “new” materials in the past, when – just to mention some examples – iron, steel and reinforced concrete were considered innovative. From Ruskin’s idea of  “crutch”, passing to the “hidden reinforcement” expressed in the Athens Charter, to some more recent examples, the past experiences offer once again the opportunity to evaluate new techniques and theoretical approaches. The authors underline the opportunity to identify a “correct methodology” rather than a “correct solution” in restoration.  Further knowledge and comprehension of a monument and – at the same time - a deep awareness of the limits and weaknesses of recent technologies and materials, may guide architects to a more efficient, respectful structural restoration project. Keywords: restoration, structure, materials, reinforcement, technique

  4. Effect of two anti-erosion pastes on surface roughness of different restorative materials.

    Science.gov (United States)

    Tirali, R E; Çehreli, S B; Yazici, R; Yalçinkaya, Z

    2013-06-01

    The aim of this study was to investigate the effect of two antierosive pastes, Pronamel and Tooth Mousse Plus, on surface roughness of two composite (Filtek Supreme Ultra Universal Restorative and TPH Spectrum Restorative), one compomer (Dyract Extra), and two conventional glass ionomer restorative materials (Ionofil U and SDI) MATERIALS AND METHODS STUDY DESIGN: 14 discs (10 mm diameter x 2 mm thickness) were prepared for each material (n =14 x 5). The discs were randomly divided into two groups to receive either GC Tooth Mousse Plus application or Sensodyne Pronamel application with toothbrush. The surface roughness of the brushed samples were recorded by laser profilometer. STATISTICS Wilcoxon, Kruskal Wallis test and multiple comparison tests were used to analyse the data. It was revealed that the surface roughness of the Filtek Supreme, TPH, Dyract and Riva Selfcure materials were not affected from application of either pastes (p>0.005). However, surface roughness of manually mixed glass ionomer (Ionofil U) was significantly increased when brushed with both Tooth Mousse and Pronamel paste (p<0.001). Neither Pronamel, nor Tooth Mousse caused a significant change on the surface roughness of tested restorative materials except Ionofil U. It was significantly increased following brushing with either paste.

  5. Evaluation of Marginal Leakage and Shear Bond Strength of Bonded Restorations in Primary Teeth after Caries Removal by Conventional and Chemomechanical Techniques.

    Science.gov (United States)

    Pravin Maru, Viral; Shakuntala, Bethur Siddaiah; Dharma, Nagarathna

    2014-01-01

    Background/Purpose. To evaluate and compare the marginal leakage and shear bond strength between conventional and Papacarie techniques of caries removal in primary molars. Materials and Methods. Sixty freshly extracted human carious primary molars were randomly divided into two groups: group I-caries removal by conventional method and group II-caries removal using Papacarie. After bonded restorations, both groups were further randomly subdivided into four subgroups for marginal leakage and shear bond strength evaluation. Results. Papacarie treated teeth (46.70%) showed less marginal leakage when compared to conventionally treated teeth (86.70%) for caries removal. The mean shear bond strength was found more in Papacarie treated teeth (12.91 MPa) than in those treated conventionally (9.64 MPa) for caries removal. Conclusion. Papacarie showed less marginal leakage and more shear bond strength when compared to those treated conventionally for caries removal.

  6. Discoloration of different esthetic restorative materials: A spectrophotometric evaluation.

    Science.gov (United States)

    Ceci, Matteo; Viola, Matteo; Rattalino, Davide; Beltrami, Riccardo; Colombo, Marco; Poggio, Claudio

    2017-01-01

    A crucial property of esthetic restorative materials is their long-term color stability. The aim of this in vitro study was to evaluate the color stability of esthetic restorative materials (one microfilled flowable composite, one nanofilled composite, one nanoybrid composite, one microfilled composite, and one nanoybrid ormocer-based composite) after surface roughening with cola and exposure to different staining solutions (coffee and red wine). All materials were polymerized into silicone rubber rings (2 mm × 6 mm × 8 mm) to obtain 150 specimens identical in size. Seventy-five specimens of Group A were first exposed to cola for 24 h, and then samples were immersed in coffee or red wine over a 28-day test period. A colorimetric evaluation, according to the CIE L*a*b* system, was performed at 7, 14, 21, 28 days. Shapiro-Wilk test and Kruskal-Wallis analysis of variance were applied to assess significant differences among restorative materials. Means were compared with Scheffe's multiple comparison test at the 0.05 level of significance. Specimens of Group A showed higher variations when compared with Group B's specimens (P materials tested (P materials tested. The first exposure to cola enhanced the subsequent staining with coffee or red wine. Nanohybrid composites reported the lowest color variations.

  7. Materials and methods for autonomous restoration of electrical conductivity

    Science.gov (United States)

    Blaiszik, Benjamin J; Odom, Susan A; Caruso, Mary M; Jackson, Aaron C; Baginska, Marta B; Ritchey, Joshua A; Finke, Aaron D; White, Scott R; Moore, Jeffrey S; Sottos, Nancy R; Braun, Paul V; Amine, Khalil

    2014-03-25

    An autonomic conductivity restoration system includes a solid conductor and a plurality of particles. The particles include a conductive fluid, a plurality of conductive microparticles, and/or a conductive material forming agent. The solid conductor has a first end, a second end, and a first conductivity between the first and second ends. When a crack forms between the first and second ends of the conductor, the contents of at least a portion of the particles are released into the crack. The cracked conductor and the released contents of the particles form a restored conductor having a second conductivity, which may be at least 90% of the first conductivity.

  8. Microleakage Evaluation Around Retrograde Filling Materials Prepared Using Conventional and Ultrasonic Techniques

    Science.gov (United States)

    Bolla, Nagesh; Thumu, Jayaprakash; Vemuri, Sayesh; Chukka, Sunil

    2015-01-01

    Introduction: The importance of the retrograde cavity preparation and the material used to restore is of utmost importance to achieve successful surgical endodontics. Aim: The aim of the present study is to evaluate the apical micro-leakage of root end cavities filled with Mineral trioxide aggregate, Biodentine and light cure GIC using two different cavity preparation techniques that is conventional bur preparation and ultrasonic tip preparation. Materials and Methods: Eighty extracted single rooted human teeth (except mandibular incisors) with one canal, fully developed apices and without any major carious lesion are collected for the study. The teeth were sectioned at CEJ to standardize the length. Roots are instrumented upto master apical file 40 K size and obturated with gutta percha and AH plus sealer in lateral condensation technique. The teeth were then resected apically at 90° angle axis to the long axis of the root removing 3 mm of the apex. The teeth were divided in to four groups of 20 each- • Group I- samples restored with MTA. • Group II- samples restored with Biodentine. • Group III- (Positive control group)- samples restored with Light activated GIC. • Group IV - (negative control group)- no filling material. Each group is divided into two subgroups (a, b) of ten teeth each 1. Retropreparation done with ultrasonic retrotip. 2. Retropreparation done with conventional bur. The teeth were then immersed in 0.5% Rhodamine B dye for 48 h. The teeth were split longitudinally and the interface between the restored material and the canal wall is observed under Confocal laser scanning microscope. Depth of dye penetration was examined under stereomicroscope. Results: The statistical analysis was performed by One way ANOVA, t test. Pair wise comparision was done by Newman – Keuls multiple post hoc test. The mean values of Dye penetration for Group Ia (321.23), Group Ib (490.11), Group IIa (1065.14), Group IIb (1170.96), Group IIIa (1888.90), Group

  9. Static slot testing of conventional lost circulation materials

    Energy Technology Data Exchange (ETDEWEB)

    Hinkebein, T.E.; Behr, V.L.; Wilde, S.L.

    1983-01-01

    A study of the utility of conventional lost circulation materials and testing methods was performed using a modified API slot tester. Five lost circulation materials were evaluated in 266 tests at both room temperature and temperature-aged conditions simulating expected geothermal environments. A large variation in the maximum pressure (or sealing pressure) the plug could withstand was attributed to nonrepeatability in plug strengths. Plugs were composed to multiple or single particle bridges, with the latter providing stronger, better sealing plugs. Seals occurred on the upstream surface of the slots in all cases. Sealing pressures generally decreased with increasing slot widths and decreasing solids concentration. When the slot width was less than the size of the largest rigid particle in the lost circulation slurry, sealing pressure was maximized. When the slot width was greater than three times the maximum rigid particle size, no significant sealing ability was observed with the conventional materials tested. Additionally, cellulosic lost circulation materials are severely degraded by temperature aging. Mud gellation provided no significant improvement in lost circulation material sealing ability.

  10. Overview: Damage resistance of graded ceramic restorative materials.

    Science.gov (United States)

    Zhang, Yu

    2012-08-01

    Improving mechanical response of materials is of great interest in a wide range of disciplines, including biomechanics, tribology, geology, optoelectronics, and nanotechnology. It has been long recognized that spatial gradients in surface composition and structure can improve the mechanical integrity of a material. This review surveys recent results of sliding-contact, flexural, and fatigue tests on graded ceramic materials from our laboratories and elsewhere. Although our findings are examined in the context of possible applications for next-generation, graded all-ceramic dental restorations, implications of our studies have broad impact on biomedical, civil, structural, and an array of other engineering applications.

  11. Recent advances in materials for all-ceramic restorations.

    Science.gov (United States)

    Griggs, Jason A

    2007-07-01

    The past 3 years of research on materials for all-ceramic veneers, inlays, onlays, single-unit crowns, and multi-unit restorations are reviewed in this article. The primary changes in the field were the proliferation of zirconia-based frameworks and computer-aided fabrication of prostheses, and a trend toward more clinically relevant in vitro test methods. This article includes an overview of ceramic fabrication methods, suggestions for critical assessment of material property data, and a summary of clinical longevity for prostheses constructed of various materials.

  12. Light induced polymerization of resin composite restorative materials

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    Blažić Larisa

    2004-01-01

    Full Text Available Introduction Dimensional stability of polymer-based dental materials is compromised by polymerization reaction of the monomer. The conversion into a polymer is accompanied by a closer packing of molecules, which leads to volume reduction called curing contraction or polymerization shrinkage. Curing contraction may break the adhesion between the adhesive system and hard tooth tissues forming micrographs which may result in marginal deterioration, recurrent caries and pulp injury. Polymerization shrinkage of resin-based restorative dental materials Polymerization of the organic phase (monomer molecules of resin-based dental materials causes shrinkage. The space occupied by filler particles is not associated with polymerization shrinkage. However, high filler loading within certain limits, can contribute to a lesser curing contraction. Polymerization shrinkage stress and stress reduction possibilities Polymerization shrinkage stress of polymer-based dental resins can be controlled in various ways. The adhesive bond in tooth-restoration interface guides the contraction forces to cavity walls. If leakage occurs, complications like secondary caries and pulpal irritation may jeopardize the longevity of a restoration. Stress relieve can be obtained by modifications of the monomer and photoinitiator, or by specially designed tooth preparation and application of bases and liners of low modulus of elasticity. The polymerization contraction can be compensated by water absorption due to oral cavity surrounding. The newest approach to stress relief is based on modulation of polymerization initiation. Conclusion This work deals with polymerization contraction and how to achieve leak-proof restoration. Restorative techniques that may reduce the negative effect of polymerization shrinkage stress need further research in order to confirm up-to-date findings.

  13. Marginal adaptation and CAD-CAM technology: A systematic review of restorative material and fabrication techniques.

    Science.gov (United States)

    Papadiochou, Sofia; Pissiotis, Argirios L

    2017-09-27

    The comparative assessment of computer-aided design and computer-aided manufacturing (CAD-CAM) technology and other fabrication techniques pertaining to marginal adaptation should be documented. Limited evidence exists on the effect of restorative material on the performance of a CAD-CAM system relative to marginal adaptation. The purpose of this systematic review was to investigate whether the marginal adaptation of CAD-CAM single crowns, fixed dental prostheses, and implant-retained fixed dental prostheses or their infrastructures differs from that obtained by other fabrication techniques using a similar restorative material and whether it depends on the type of restorative material. An electronic search of English-language literature published between January 1, 2000, and June 30, 2016, was conducted of the Medline/PubMed database. Of the 55 included comparative studies, 28 compared CAD-CAM technology with conventional fabrication techniques, 12 contrasted CAD-CAM technology and copy milling, 4 compared CAD-CAM milling with direct metal laser sintering (DMLS), and 22 investigated the performance of a CAD-CAM system regarding marginal adaptation in restorations/infrastructures produced with different restorative materials. Most of the CAD-CAM restorations/infrastructures were within the clinically acceptable marginal discrepancy (MD) range. The performance of a CAD-CAM system relative to marginal adaptation is influenced by the restorative material. Compared with CAD-CAM, most of the heat-pressed lithium disilicate crowns displayed equal or smaller MD values. Slip-casting crowns exhibited similar or better marginal accuracy than those fabricated with CAD-CAM. Cobalt-chromium and titanium implant infrastructures produced using a CAD-CAM system elicited smaller MD values than zirconia. The majority of cobalt-chromium restorations/infrastructures produced by DMLS displayed better marginal accuracy than those fabricated with the casting technique. Compared with copy

  14. Evaluation of the effect of adding micro-hydroxyapatite and nano-hydroxyapatite on the microleakage of conventional and resin-modified Glass-ionomer Cl V restorations

    Science.gov (United States)

    Sharafeddin, Farahnaz

    2017-01-01

    Background Pulpal reaction to restorative materials depends on marginal microleakage, which is a dynamic phenomenon that allows bacteria and fluids to traverse across the tooth-restoration interface. Glass-ionomer cement (GIC) exhibits low microleakage due to direct bonding to tooth structures. Hydroxyapatite (HAP) based on the similarity with tooth structure may decrease the microleakage. The aim of this in vitro study was to evaluate marginal microleakage of a mixture of conventional and resin-modified glass-ionomer (RMGI) with micro- and nano-HAP. Material and Methods In this in vitro study, 30 non-carious extracted human third molar teeth were used. Standard Cl V cavities were prepared on the buccal and lingual surfaces. The cavities were restored in six experimental groups as follows: group 1, conventional glass-ionomer cement (CGIC); group 2, CGIC with micro-HAP; group 3, CGIC with nano-HAP; group 4, RMGI; group 5, RMGI with micro-HAP; group 6, RMGI with nano-HAP. The restorations were finished and polished. The teeth were coated with nail polish, sealed with sticky wax, thermocycled and placed in a solution of 2% basic fuchsine for 24 hours. The teeth were sectioned and microleakage was measured. Kruskal-Wallis, Man-Whitney and Wilcoxon tests were used for data analysis (PGlass-ionomer, micro-hydroxyapatite, microleakage, nano-hydroxyapatite. PMID:28210443

  15. The material science of minimally invasive esthetic restorations.

    Science.gov (United States)

    Nový, Brian B; Fuller, Cameron E

    2008-01-01

    The term esthetic dentistry usually conjures up mental images of porcelain crowns and veneers. To some dentists, the term minimally invasive dentistry evokes thoughts of observing early lesions, and postponing treatment until lesions are closer to the pulp. (The World Congress of Minimally Invasive Dentistry defines minimally invasive dentistry as those techniques which respect health, function, and esthetics of oral tissue by preventing disease from occurring, or intercepting its progress with minimal tissue loss.) It would seem these two niches within dentistry are on opposite ends of the spectrum; however, composite resin and glass ionomer restorative materials unite these two ideologies. Understanding the limitations, benefits, and science behind each material allows clinicians to produce highly esthetic restorations that can resist future decay, internally remineralize the tooth, and help protect adjacent teeth from cariogenic attack.

  16. Enamel wear caused by three different restorative materials.

    Science.gov (United States)

    Hudson, J D; Goldstein, G R; Georgescu, M

    1995-12-01

    The ideal restorative material should cause minimal wear of opposing enamel. This study compared the effects of gold alloy, glazed porcelain, and a laboratory-processed composite on opposing enamel. Ten samples of a type III gold alloy, a porcelain, and a visible-light, heat, and vacuum-processed composite were abraded against cusps of extracted molars for 10,000 cycles on an abrading machine. Pretest and posttest profilometric measurements of the restorative materials demonstrated no statistical difference. Pretest and posttest tracings of the cusps were made on an optical comparator to determine loss of vertical height and surface area. The porcelain caused significantly more loss of vertical height and surface area than the gold alloy or the composite, which were similar.

  17. Reliability and properties of core materials for all-ceramic dental restorations

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    Seiji Ban

    2008-07-01

    Full Text Available Various core materials have been used as all-ceramic dental restorations. Since many foreign zirconia product systems were introduced to the Japanese dental market in the past few years, the researches and the papers on zirconia for ceramic biomaterials have immediately drawn considerable attention. Recently, most of the manufactures supply zirconia blocks available to multi-unit posterior bridges using CAD/CAM, because zirconia has excellent mechanical properties comparable to metal, due to its microstructures. The properties of conventional zirconia were further improved by the composite in nano-scale such as zirconia/alumina nanocomposite (NANOZR. There are many interesting behaviors such as long-term stability related to low temperature degradation, effect of sandblasting and heat treatment on the microstructure and the strength, bonding to veneering porcelains, bonding to cement, visible light translucency related to esthetic restoration, X-ray opacity, biocompatibility, fracture load of clinical bridge as well as lifetime and clinical survival rates of the restoratives made with zirconia. From the recent material researches on zirconia not only in Japan but also in the world, this review takes into account these interesting properties of zirconia and reliability as core material for all-ceramic dental restorations.

  18. Evaluation of color stability of different temporary restorative materials

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    José Vitor Quinelli Mazaro

    Full Text Available AbstractIntroductionTemporary restorative materials are widely used, however, little is know about their color stability.Objectiveto evaluate the color stability of the following temporary restorative materials: acrylic and bis-acrylic resins after immersion in pigmenting solutions for different periods of storage.Material and methodFour materials were tested (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG and 30 test specimens (15 mm in diameter and 2 mm thick per material were fabricated. They were divided according to the storage medium (artificial saliva, saliva + cola type soda, and saliva + coffee and storage time intervals (2, 5, 7 and 15 days. Color measurements were made before and after immersions, with use of a spectrophotometer, by means of the CIE L*a*b* system. The data were analyzed by the analysis of variance and the Tukey Test, at a level of significance of 5%.ResultAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001. When bis-acrylic resins were compared no significant difference was observed between the resins Structur and Luxatemp (p=0.767. As regards solutions tested, coffee showed the highest color change values (p<0.001, and the longer the storage time interval, the greater was the color change in all the temporary restorative materials analyzed (p<0.001.ConclusionAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001. Coffee caused the greatest color change, and immersion time was determinant in color stability of the temporary materials analyzed.

  19. Cariostatic effect of fluoride-containing restorative materials associated with fluoride gels on root dentin

    Directory of Open Access Journals (Sweden)

    Fernanda Tavares Borges

    2010-10-01

    Full Text Available Secondary caries is still the main cause of restoration replacement, especially on the root surface OBJECTIVE: This in vitro study evaluated the cariostatic effects of fluoride-containing restorative materials associated with fluoride gels, on root dentin. MATERIALS AND METHODS: A randomized complete block design was used to test the effects of the restorative systems, fluoride regimes and the interactions among them at different distances from restoration margins. Standardized cavities were prepared on 240 bovine root specimens and randomly assigned to 15 groups of treatments (n=16. Cavities were filled with the following restorative materials: Ketac-Fil (3M-ESPE; Vitremer (3M-ESPE; Dyract/Prime & Bond NT (Dentsply; Charisma/Gluma One Bond (Heraeus Kulzer and the control, Z250/Single Bond (3M-ESPE. The specimens were subjected to a pH-cycling model designed to simulate high-caries activity. During the cycles, 1.23% acidulated phosphate fluoride, 2.0% neutral sodium fluoride or deionized/distilled water (control was applied to the specimens for 4 min. The surface Knoop microhardness test was performed before (KHNi and after (KHNf the pH cycles at 100, 200 and 300 mm from the margins. Dentin microhardness loss was represented by the difference in initial and final values (KHNi - KHNf. Data were analyzed by Friedman's and Wilcoxon's tests, ANOVA and Tukey's test (α=5%. RESULTS: The interaction of restorative systems and topical treatments was not significant (p=0.102. Dentin microhardness loss was lowest closer to the restoration. Ketac-fil presented the highest cariostatic effect. Vitremer presented a moderate effect, while Dyract and Charisma did not differ from the control, Z250. The effects of neutral and acidulated fluoride gels were similar to each other and higher than the control. CONCLUSION: Conventional and resin-modified glass ionomer cements as well as neutral and acidulated fluoride gels inhibit the progression of artificial caries

  20. Effect of curing with a plasma light on the properties of polymerizable dental restorative materials.

    Science.gov (United States)

    Millar, B J; Nicholson, J W

    2001-06-01

    Specimens of light-curable dental restoratives have been prepared using either a conventional dental curing lamp (for 20 or 30 s) or a plasma light (for 1 or 2 s). The specimens were then stored in water until their mass equilibrated, then dried to constant mass. Most specimens lost material in this process but the losses in all specimens cured with the plasma light were significantly greater than those cured with the conventional lights (P cure times gave slightly reduced losses in water in most cases. The specimens were then returned to water and allowed to re-equilibrate and their equilibrium water uptake determined. There was no simple trend in this latter property because elution of loosely bound hydrophilic species may have resulted in a less hydrophilic specimen, whose equilibrium water content was therefore correspondingly lower. Overall, the losses through dissolution in water suggest that plasma curing is less effective for these materials than conventional light curing, as it probably results in material with lower molar mass. The losses for the resin-modified glass-ionomer were much greater than for other materials, and it was concluded that the more rapid polymerization with plasma light caused a significant inhibitation of the acid-base part of the setting process. These findings suggest that long-term durability of materials may be compromised by employing plasma light cure rather than a conventional cure system and further studies of this point are recommended.

  1. Resin-modified and conventional glass ionomer restorations in primary teeth: 8-year results

    DEFF Research Database (Denmark)

    Qvist, V.; Manscher, E.; Teglers, P.T.

    2004-01-01

    clinical trial, cariostatic effects, dental restorations, glass ionomer cement, long-term behaviour, pedodontics, resin-modified glass ionomer......clinical trial, cariostatic effects, dental restorations, glass ionomer cement, long-term behaviour, pedodontics, resin-modified glass ionomer...

  2. Candida albicans adherence to glass ionomer restorative dental material

    Directory of Open Access Journals (Sweden)

    Shirin Lawaf

    2009-06-01

    Full Text Available Background and aims. It is believed that adherence of Candida albicans to oral surfaces is a critical event in the colonization and development of oral diseases such as candida-associated denture stomatitis. Although there is considerable information about the adherence of Candida albicans to buccal epithelial cells and prosthetic materials, there is very little information available about the adherence of Candida albicans to glass ionomer materials. The purpose of this study was to investigate the degree of Candida albicans adherence to glass ionomer restorative material. Materials and methods. In this experimental study adherence of Candida albicans strains was studied with and without human whole saliva. First, glass ionomer fragments were prepared; then yeast cells were inoculated and incubated with different incubation times. After incubation, the fragments were removed from the wells and stained with 0.1% calcofluor white. Adhesion was quantified by counting the total number of cells at 40, 80 and 120 minutes. The analysis of variance and Student's test were used to assess the significance of differences between the means. Results. In the absence of saliva, the adherence of Candida albicans showed an increase, reaching a maximum at the end of the experiment (120 minutes. However, in the presence of saliva, the adherence of Candida albicans to glass ionomer significantly decreased. Conclusion. The presence of human whole saliva is an important factor in the adherence of Candida albicans to glass ionomer restorative material.

  3. Finite element stress analysis of short-post core and over restorations prepared with different restorative materials.

    Science.gov (United States)

    Gurbuz, Taskin; Sengul, Fatih; Altun, Ceyhan

    2008-07-01

    The present study was conducted to determine the effect on the distribution of stress with the use of short-post cores and over restorations composed of different materials. The restorative materials used were namely two different composite resin materials (Valux Plus and Tetric Flow), a polyacid-modified resin material (Dyract AP), and a woven polyethylene fiber combination (Ribbond Fiber + Bonding agent + Tetric Flow). Finite element analysis (FEA) was used to develop a model for the maxillary primary anterior teeth. A masticatory force of 100 N was applied at 148 degrees to the incisal edge of the palatal surface of the crown model. Stress distributions and stress values were compared using von Mises criteria. The tooth model was assumed to be isotropic, homogeneous, elastic, and asymmetrical. It was observed that the highest stress usually occurred in the cervical area of the tooth when Tetric Flow was used as the short-post core and over restoration material. The same maximum stress value was also obtained when Ribbond fiber + Tetric Flow material was used for the short-post core. The results of FEA showed that the mechanical properties and elastic modulus of the restorative material influenced the stresses generated in enamel, dentin, and restoration when short-post core restorations were loaded incisally. Resin-based restorative materials with higher elastic moduli were found to be unsuitable as short-post core materials in endodontically treated maxillary primary anterior teeth.

  4. Poor quality evidence suggests that failure rates for atraumatic restorative treatment and conventional amalgam are similar.

    Science.gov (United States)

    Hurst, Dominic

    2012-06-01

    The Medline, Cochrane CENTRAL, Biomed Central, Database of Open Access Journals (DOAJ), OpenJ-Gate, Bibliografia Brasileira de Odontologia (BBO), LILACS, IndMed, Sabinet, Scielo, Scirus (Medicine), OpenSIGLE and Google Scholar databases were searched. Hand searching was performed for journals not indexed in the databases. References of included trials were checked. Prospective clinical trials with test and control groups with a follow up of at least one year were included. Data abstraction was conducted independently and clinical and methodologically homogeneous data were pooled using a fixed-effects model. Eighteen trials were included. From these 32 individual dichotomous datasets were extracted and analysed. The majority of the results show no differences between both types of intervention. A high risk of selection-, performance-, detection- and attrition bias was identified. Existing research gaps are mainly due to lack of trials and small sample size. The current evidence indicates that the failure rate of high-viscosity GIC/ART restorations is not higher than, but similar to that of conventional amalgam fillings after periods longer than one year. These results are in line with the conclusions drawn during the original systematic review. There is a high risk that these results are affected by bias, and thus confirmation by further trials with suitably high numbers of participants is needed.

  5. Effects of ultrasonic and sonic scaling on surfaces of tooth-colored restorative materials: An in vitro study.

    Science.gov (United States)

    Erdilek, D; Sismanoglu, S; Gumustas, B; Efes, B G

    2015-01-01

    The effects of sonic and ultrasonic scalings (USSs) on the surface roughness of nanohybrid, flowable, and polyacid-modified resin composites and conventional glass ionomer cement were examined, and the effectiveness of repolishing on the scaled material surfaces was determined. The surface roughness of each sample was measured three times before and after each scaling and after repolishing, and the data were analyzed using repeated measuresanalysis of variance, Tukey's multiple comparisons, and paired t-tests by a statistical program. Although sonic and USS both significantly increased the surface roughness of all the tooth-colored materials, USS roughened the surfaces of all the test materials more than SS did. Hence, USS may detrimentally affect tooth-colored restorative materials, especially conventional glass ionomers and compomers. Repolishing decreased the surface roughness of all the materials to near their baseline levels. On the basis of these results, the repolishing of restoration surfaces is strongly recommended after dental scalings.

  6. Survival of self-etch adhesive Class II composite restorations using ART and conventional cavity preparations in primary molars.

    NARCIS (Netherlands)

    Eden, E.; Topaloglu-Ak, A.; Frencken, J.E.F.M.; Hof, M.A. van 't

    2006-01-01

    PURPOSE: To test the null-hypothesis that there was no difference in the survival percentages of Class II composite restorations in primary teeth produced through either ART or conventional approaches after 2 years. METHODS: 157 children with 325 Class II cavitated dentin lesions were included in a

  7. Evaluation of Four Different Restorative Materials for Restoration of the Periodontal Condition of Wedge-Shaped Defect: A Comparative Study.

    Science.gov (United States)

    Ruan, Jian-Yong; Gong, Zheng-Lin; Zhang, Rui-Zhi; Zhang, Zhe; Xu, Ran; Li, Da-Xu; Ren, Le; Tao, Hong

    2017-09-16

    BACKGROUND This study aimed to conduct a clinical evaluation of four restorative materials for restoration of dental wedge-shaped defect (WSD) and their impacts on periodontal tissues. MATERIAL AND METHODS A total of 280 maxillary premolars with dental WSD were selected from 106 patients; the patient cases were divided into eight groups according to different combinations of restorative materials (flowable resin composites, Dyract compomers, glass ionomer cement (GIC), light-curing composite resin), and WSD positions (approaching gingival and subgingival positions). Gingival crevicular fluid (GCF) volume, levels of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and interleukin-1β (IL-1β) in GCF were analyzed, while probing depth (PD), plaque index (PLI), and sulcus bleeding index (SBI) were also measured. The periodontal conditions of all patients were followed prior to restoration, as well as six months and 12 months after restoration. RESULTS After six months of restoration, the overall clinical success rates of flowable resin composites, Dyract compomers, and light-curing composite resin were greater than those of GIC. GCF volume, GCF-AST, IL-1β levels, PD, PLI, and SBI of cases restored by GIC were higher than those restored by the other three materials. After 12 months of restoration, the overall clinical success rates of flowable resin composites and Dyract compomers were greater than those of light-curing composite resin and GIC. GCF volume, GCF-AST, GCF-ALP, IL-1β levels, PD, PLI, and SBI of cases restored by GIC were higher than those restored by the other three materials. CONCLUSIONS Our study provided evidence that the clinical efficacy of flowable resin composites, Dyract compomers, and light-curing composite resin was greater than that of GIC for restoration of dental WSD.

  8. Visual evaluation of in vitro cariostatic effect of restorative materials associated with dentifrices.

    Science.gov (United States)

    Rodrigues, José Augusto; Marchi, Giselle Maria; Serra, Mônica Campos; Hara, Anderson Takeo

    2005-01-01

    This study evaluated in vitro the cariostatic effect of 6 restorative materials with and without fluoride release (Fuji II LC, F-2000, Degufil Mineral, Sure Fil and Z-250) associated with a fluoridated and a non-fluoridated dentifrice (Sensodyne Original Formula and Sensodyne Sodium Bicarbonate), on human enamel. Class V-like cavities were prepared on 240 enamel slabs, assigned to 12 groups (6 materials and 2 dentifrices). After cavity restoration, the slabs were submitted to a thermocycling regimen of 1000 thermal cycles and demineralization/remineralization cycles. During pH cycles, slurries of fluoridated and non-fluoridated dentifrices were applied for 5 min. Formation of artificial caries-like lesions was scored independently and blindly by 5 calibrated examiners according to an ordinal scale ranked 0 to 3 by visual examination. The results were analyzed statistically by the Kruskal-Wallis test and pair-wise comparisons (alpha=0.05). There were no significant differences (p>0.05) among the restorative materials associated with the fluoridated dentifrice. When used in association with the non-fluoridated dentifrice, Ketac-Fil showed the highest cariostatic effect followed by Fuji II LC and the other materials. Ketac-Fil was the only material that did not differ statistically when combined with either the fluoridated or the non-fluoridated dentifrice. In conclusion, under the tested experimental conditions, the association of restorative materials and fluoridated dentifrice yielded higher cariostatic effect, except for the conventional glass ionomer cement, whose cariostatic effect was not influenced by the type of dentifrice.

  9. Initial in vitro bacterial adhesion on dental restorative materials.

    Science.gov (United States)

    Kim, Ha-Young; Yeo, In-Sung; Lee, Jai-Bong; Kim, Sung-Hun; Kim, Dae-Joon; Han, Jung-Suk

    2012-10-01

    The purpose of this study was to evaluate initial bacterial adhesion on several restorative materials with similar roughness. Sixty cylindrical slabs were prepared from four restorative materials: zirconia (Zr), alumina-toughened zirconia (Al-Zr), type III gold alloy (Au), and cp-titanium (Ti). All the materials were polished until a mirror-like shine was achieved. The average surface roughness and topography were determined by atomic force microscopy. Contact angles were measured to calculate surface free energy by the sessile drop technique. After the formation of a salivary pellicle, S. sanguinis, S. gordonii, and S. oralis were inoculated onto the specimens and incubated for 4 h. Quantification of the adherent bacteria was performed by crystal violet staining technique and resazurin reduction assay. One-way ANOVA and Tukey's post hoc test were adopted for statistical analysis. The level of significance was 0.05. The Ra values determined with atomic force microscopy for all specimens were lower than 5 nm. Surface free energy increased in the order of Al-Zr, Zr, Ti, and Au. Differences were significant between the investigated materials in both crystal violet absorbance and fluorescence intensities. Gold alloy showed the highest values for all bacterial strains (padhesion and subsequent advance of peri-implantitis.

  10. In situ effects of restorative materials on dental biofilm and enamel demineralisation.

    Science.gov (United States)

    Sousa, R P; Zanin, I C J; Lima, J P M; Vasconcelos, S M L C; Melo, M A S; Beltrão, H C P; Rodrigues, L K A

    2009-01-01

    Since secondary caries is one of the main reasons for replacing restorations, this study assessed the effects of different restorative materials on the microbiological composition of dental biofilm and on enamel demineralisation around the restoration. A randomized, double-blind, split-mouth in situ design was conducted in one phase of 14 days, during which, 20 volunteers wore palatal devices containing five human dental enamel slabs. Each slab was randomly restored with one of the following materials: Filtek-Z-250/Single Bond, control group (composite resin), Permite (amalgam), Fuji II (encapsulated resin-modified glass ionomer), Vitremer (resin-modified glass ionomer) and Ketac Molar (conventional glass ionomer). The volunteers used fluoride dentifrice, 3x/day and a 20% sucrose solution was dripped onto the slabs 8x/day. The biofilm formed on the slabs was analyzed to determine the counts of total streptococci, mutans streptococci and lactobacilli. Enamel demineralisation was determined by cross-sectional microhardness (CSMH) at 20 and 70 microm from the margin of the restoration. Kruskal-Wallis and analysis of variance, followed by least mean squares (LMS) test, were used to evaluate microbiota and CSMH among the groups. The significance level used was 5%. No statistically significant differences were found in the cariogenic microbiota grown on the slabs. At a 20-mum distance, only Fuji II statistically differed from the other groups, showing the lowest demineralisation. At 70 microm, Fuji II significantly inhibited demineralisation when compared to Permite, Filtek-Z-250 and Ketac Molar. In the context of fluoride dentifrice and under the cariogenic exposure conditions of this study, only the encapsulated resin-modified glass ionomer material provided additional protection against secondary caries.

  11. Analysis of microleakage of temporary restorative materials in primary teeth

    Directory of Open Access Journals (Sweden)

    Geórgia Linhares dos Santos

    2014-01-01

    Full Text Available Aim: The aim of this study was to compare the coronal microleakage of restorative materials used between sessions of endodontic treatment in primary teeth. Materials and Methods: Forty healthy primary canines were chosen and randomly allocated to four groups: Group 1 - Cimpat Branco ® (n = 10, Group 2 - Bioplic ® (n = 10, Group 3 - Maxxion R ® glass ionomer cement (n = 10, and Group 4 (control - Z350 ® composite resin (n = 10. Class V cavities were created and fillings carried out following the manufacturer′s instructions. The teeth were submitted to thermocycling, sealed, and immersed in 0.5% basic fuchsin solution for 24 h. The teeth were split along their long axis in the vestibulolingual direction and the tooth-restorative material interface was photographed. The percentage of microleakage was calculated using the ImageJ program. Data were analyzed using the analysis of variance (ANOVA F-test and Bonferroni′s t-test, with a 5% level of significance. Results: The following mean percentages of microleakage were found: Group 1 = 16.08%, Group 2 = 46.98%, Group 3 = 47.93%, and Group 4 = 11.03%. Statistically, significant differences were found in the comparison of Groups 1 and 4 to Groups 2 and 3. Conclusion: Cimpat Branco ® had a lower percentage of microleakage in comparison to Bioplic ® and Maxxion R ® glass ionomer cement.

  12. A revised classification for direct tooth-colored restorative materials.

    Science.gov (United States)

    Mount, Graham J; Tyas, Martin J; Ferracane, Jack L; Nicholson, John W; Berg, Joel H; Simonsen, Richard J; Ngo, Hien C

    2009-09-01

    Composite resins and glass-ionomer cements were introduced to dentistry in the 1960s and 1970s, respectively. Since then, there has been a series of modifications to both materials as well as the development other groups claiming intermediate characteristics between the two. The result is a confusion of materials leading to selection problems. While both materials are tooth-colored, there is a considerable difference in their properties, and it is important that each is used in the appropriate situation. Composite resin materials are esthetic and now show acceptable physical strength and wear resistance. However, they are hydrophobic, and therefore more difficult to handle in the oral environment, and cannot support ion migration. Also, the problems of gaining long-term adhesion to dentin have yet to be overcome. On the other hand, glass ionomers are water-based and therefore have the potential for ion migration, both inward and outward from the restoration, leading to a number of advantages. However, they lack the physical properties required for use in load-bearing areas. A logical classification designed to differentiate the materials was first published by McLean et al in 1994, but in the last 15 years, both types of material have undergone further research and modification. This paper is designed to bring the classification up to date so that the operator can make a suitable, evidence-based, choice when selecting a material for any given situation.

  13. A comparison of the fracture resistances of endodontically treated mandibular premolars restored with endocrowns and glass fiber post-core retained conventional crowns

    Science.gov (United States)

    Guo, Jing; Wang, Zhiming; Li, Xuesheng; Sun, Chaoyang; Gao, Erdong

    2016-01-01

    PURPOSE This in-vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post-core retained crowns. MATERIALS AND METHODS Thirty mandibular premolars were assigned into three groups (n=10): GI, intact teeth; GE, teeth with endocrowns; GC, teeth with conventional post-core supported crowns. Except for the teeth in group GI, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. Both endocrowns and conventional crowns were fabricated from lithium-disilicate blocks using a CEREC 3D CAD/CAM unit. All specimens were subjected to thermocycling and then to 45° oblique compressive load until fracture occurred. The fracture resistance and failure mode of each specimen were recorded. Data were analyzed with one-way ANOVA and LSD Post Hoc Test (α=.05). RESULTS The fracture resistances of GE and GC were significantly lower than that of GI (P<.01), while no significant difference was found between GE and GC (P=.702). As of the failure mode, most of the specimens in GE and GC were unfavorable while a higher occurrence of favorable failure mode was presented in GI. CONCLUSION For the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. Both of the two methods cannot rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have. PMID:28018567

  14. A randomized controlled 30 years follow up of three conventional resin composites in Class II restorations

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2015-01-01

    of the enamel. The chemical-cured resincomposites were placed in bulk and the light-cured in increments. One operator placed 99restorations (33 sets). The restorations were evaluated with slightly modified USPHS crite-ria at baseline, 2, 3, 5, 10, 15, 20 and 30 years. Statistical analyses were performed by the...

  15. STUDY OF SURFACE PHENOMENA IN MATERIALS OF PROSTHETIC RESTORATION

    Directory of Open Access Journals (Sweden)

    Mihaela-Păpuşa Vasiliu

    2012-12-01

    Full Text Available As a direct consequence of their application domain – the oral cavity – dental materials are subjected to the corosive action of saliva, being surrounded by microorganisms, fluids and alimentary rests, which modify their surface characteristics. Concerns on the quality of the dental materials explain the numeorus interdisciplinary studies, characterized by a close relation among various scientific domains (physics, chemistry, biology, science of biomaterials, techniques also applied in clinical stomatology. Analysis of the saliva–dental materials interface made use of ceramic surfaces, composites and artificial saliva, permitting to determine the main surface parameters of the materials of prosthetic restoration, calculated with some physical models, starting from measurements of the contact angle: surface energy, its polar and dispersive components, surface rugosity, adhesion mechanic work. All composites showed low values of the adhesion mechanic work, the conclusion being that they are much more hydrophobic than the ceramic materials. Such a property is especially important from an aesthetic perspective, as the hydrophobic materials have a better colour stability in time.

  16. Embryotoxicity assays for leached components from dental restorative materials

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    Mummolo Stefano

    2011-10-01

    Full Text Available Abstract Background Currently, there are no suitable assays available to evaluate the embryotoxicity of leached components from restorative dental materials. Methods The effect of the medium conditioned by composites and amalgam on mouse blastocysts in vitro was tested. The materials were also subcutaneously implanted, and the effect of the medium supplemented with serum from the host blood was evaluated in the embryotoxicity assay. The embryo implantation rate in the material-transplanted mothers was also evaluated. Results The results show that while the culture in media conditioned by amalgams did not affect blastocyst development, the medium conditioned by composites caused blastocyst degeneration and apoptosis. The development of blastocysts in a medium containing serum obtained from animals after transplantation was, however, without effect. Finally, inconsistent reduction in the implantation rate in transplanted mothers was observed. Conclusions In this study, we provide examples of in vitro and in vivo tests that may be used to evaluate embryotoxicity for dental materials. Our results show that leached components from our composite-material induced embryotoxicity in vitro, however, no toxicity was observed when subcutaneously implanted in vivo. This highlights the necessity of integrated in vitro and in vivo tests for valuable predictive estimation of embryotoxicity for complex materials.

  17. Criteria for clinical translucency evaluation of direct esthetic restorative materials

    Science.gov (United States)

    2016-01-01

    The purpose of this review was to suggest practical criteria for the clinical translucency evaluation of direct esthetic restorative materials, and to review the translucency with these criteria. For the evaluation of reported translucency values, measuring instrument and method, specimen thickness, background color, and illumination should be scrutinized. Translucency parameter (TP) of 15 to 19 could be regarded as the translucency of 1 mm thick human enamel. Visual perceptibility threshold for translucency difference in contrast ratio (ΔCR) of 0.07 could be transformed into ΔTP value of 2. Translucency differences between direct and indirect resin composites were perceivable (ΔTP > 2). Universal and corresponding flowable resin composites did not show perceivable translucency differences in most products. Translucency differed significantly by the product within each shade group, and by the shade group within each product. Translucency of human enamel and perceptibility threshold for translucency difference may be used as criteria for the clinical evaluation of translucency of esthetic restorative materials. PMID:27508156

  18. Colour measurements of surfaces to evaluate the restoration materials

    Science.gov (United States)

    Lo Monaco, Angela; Marabelli, Maurizio; Pelosi, Claudia; Picchio, Rodolfo

    2011-06-01

    In this paper two case studies on the application of colour measurements for the evaluation of some restoration materials are discussed. The materials related to the research are: watercolours employed in restoration of wall paintings and preservative/consolidants for wood artifacts. Commercial watercolours, supplied by Maimeri, Windsor&Newton and Talens factories have been tested. Colour measurements have been performed by means of a reflectance spectrophotometer (RS) before and after accelerated ageing of watercolours at 92% relative humidity (RH) and in a Solar Box chamber. The experimental results show that watercolours based on natural earths and artificial ultramarine undergo the main colour changes, expressed as L*, a* and b* variations and total colour difference (▵E*). In the other cases colour differences depend on both watercolour typology and suppliers. The other example concerns the evaluation of colour change due to surface treatment of Poplar (Populus sp.) and chestnut (Castanea sativa L.) wood samples. The wooden samples have been treated with a novel organic preservative/consolidant product that has been tested also in a real case as comparison. The treated samples have been artificially aged in Solar Box chamber equipped with a 280 nm UV filter. Colour has been measured before and after the artificial ageing by means of a RS. Colour changes have been determined also for the main door of an historical mansion in Viterbo, made of chestnut wood, and exposed outdoors.

  19. Criteria for clinical translucency evaluation of direct esthetic restorative materials.

    Science.gov (United States)

    Lee, Yong-Keun

    2016-08-01

    The purpose of this review was to suggest practical criteria for the clinical translucency evaluation of direct esthetic restorative materials, and to review the translucency with these criteria. For the evaluation of reported translucency values, measuring instrument and method, specimen thickness, background color, and illumination should be scrutinized. Translucency parameter (TP) of 15 to 19 could be regarded as the translucency of 1 mm thick human enamel. Visual perceptibility threshold for translucency difference in contrast ratio (ΔCR) of 0.07 could be transformed into ΔTP value of 2. Translucency differences between direct and indirect resin composites were perceivable (ΔTP > 2). Universal and corresponding flowable resin composites did not show perceivable translucency differences in most products. Translucency differed significantly by the product within each shade group, and by the shade group within each product. Translucency of human enamel and perceptibility threshold for translucency difference may be used as criteria for the clinical evaluation of translucency of esthetic restorative materials.

  20. Restoration materials and secondary caries using an in vitro biofilm model

    NARCIS (Netherlands)

    Kuper, N.K.; van de Sande, F.H.; Opdam, N.J.M.; Bronkhorst, E.M.; de Soet, J.J.; Cenci, M.S.; Huysmans, M.C.D.N.J.M.

    2015-01-01

    This in vitro study investigated whether restoration materials and adhesives influence secondary caries formation in gaps using a short-term in vitro biofilm model. Sixty enamel-dentin blocks were restored with 6 different restoration materials with or without adhesives (n = 10 per group) with a

  1. In situ reaction kinetic analysis of dental restorative materials

    Science.gov (United States)

    Younas, Basma; Samad Khan, Abdul; Muzaffar, Danish; Hussain, Ijaz; Chaudhry, Aqif Anwar; Rehman, Ihtesham Ur

    2013-12-01

    The objective of this study was to evaluate in situ structural and thermal changes of dental restorative materials at periodical time intervals. The commercial materials included zinc oxide eugenol (ZOE), zinc phosphate type I (ZnPO4), glass ionomer cement type II (GIC) and resin-based nano-omposite (Filtek Z350 XT). These materials were processed according to manufacturer's instructions. For the structural analysis Fourier transform infrared spectroscopy (FTIR) was used at high resolution. TGA was used to evaluate thermal weight-loss. The FTIR spectra were collected at periodic time intervals. FTIR spectra showed that with time passing all materials exhibited an increase in peak intensities and a new appearance of shoulders and shifting of peaks for example, ZnPO4 (P-O), ZOE (C═O, C═N, C-O-C), GIC (COO-, C-H, Si-OH), composites (C═O, C═C, C═N, C-N-H). The peaks were replaced by bands and these bands became broader with time interval. Composites showed a degree of conversion and new peaks corresponded to the cross-linking of polymer composites. TGA analysis showed that significant changes in weight loss of set materials were observed after 24 h, where ZOE showed continuous changes in thermal degradation. The spectral changes and thermal degradation with time interval elucidated in situ setting behaviour and understanding of their bonding compatibility with tooth structure and change in relation to time.

  2. In vitro color stability of provisional restorative materials

    Directory of Open Access Journals (Sweden)

    Hamid Jalali

    2012-01-01

    Aims: The purpose of this study was to investigate the effect of tea on provisional restorative materials. Setting and Design: This study was designed to measure the degree of color change of three acrylic resin provisional materials, before and after immersion in artificial saliva and artificial saliva-tea solution for 2 and 4 weeks. Materials and Methods : Three types of acrylic provisional materials (duralay, tempron, acropars TRP, were studied. Twenty disks (20±0.1 mm by 2±0.05 mm were fabricated from each material. Specimens were polished with acrylic bur using pumice and diamond polishing paste. Base line color was measured using a spectrophotometer. Ten disks were stored in artificial saliva and 10 were stored in a solution of artificial saliva and tea at room temperature. Color measurements were made after 2 and 4 weeks of immersion. Statistical analysis used: Differences in color changes were compared by two way ANOVA, across the six groups, followed by a Turkey-Kramer′s multiple comparison test. Results: For specimens immersed in artificial saliva, the color change of methyl methacrylate materials; duralay (ΔE=4.94 and tempron (ΔE=6.54, was significantly more than butyl methacrylate material; acropars (ΔE=4.10. After immersion in an artificial saliva- tea solution, tempron exhibited less color change (ΔE=8.50 compared to duralay (ΔE=10.93 and acropars (ΔE=15.64. Conclusion: Color stability of methyl methacrylate is higher than butyl methacrylates so if provisional materials are used for extended periods of time; tempron is preferred.

  3. A comparison of an accelerated technique for casting post-and-core restorations with conventional techniques.

    Science.gov (United States)

    Campagni, W V; Reisbick, M H; Jugan, M

    1993-09-01

    This project compares an accelerated technique for the casting of post-and-core restorations with four traditional techniques. The accelerated technique uses two phosphate-bonded investments and the traditional techniques use a gypsum- and a phosphate-bonded investment. The study measures and compares the differences between the seating of the casting and the seating of the acrylic resin pattern. The effects of the techniques on the fit of castings with and without a ferrule are also compared. Six groups of 10 castings were made from plastic patterns formed on a stainless steel test die. A different investment and/or burnout method was used for each group. Each group had two subgroups: ferruled and nonferruled. The fit of the plastic patterns was measured at two time intervals after forming, 2 weeks and 3 months. The patterns were invested immediately after the 3-month measurement, and the difference in fit of the castings was calculated. An ANOVA and Tuckey-Kramer test were done to determine the statistical validity. The seating of the patterns after 3 months of storage was consistently worse than the 2-week measurements of fit. The ferrule and nonferrule patterns were not statistically different in seating. Measurement of the castings showed that the ferruled castings seated significantly worse than the nonferrule castings. The difference in the seating of the castings as compared with the patterns was considered clinically unacceptable, showing a range of 0.301 mm to 0.528 mm. The nonferrule castings showed a significant difference in seating among groups. The difference ranged from -0.099 mm to 0.322 mm. The castings of the ferrule subgroups were considered clinically unacceptable and were not analyzed for significance. Among the nonferrule castings, the group using a gypsum investment and conventional technique for investing and burnout but no ring liner showed the best seating. The accelerated technique was intermediate in seating with a difference of 0

  4. Repeated exposure of acidic beverages on esthetic restorative materials: an in-vitro surface microhardness study

    OpenAIRE

    Xavier, Arun M.; Sunny, Steffy M.; Rai, Kavita; Amitha M Hegde

    2016-01-01

    Background A manifold increase in the consumption of aerated beverages has witnessed a twin increase in tooth wear and raised demand for esthetic restorative materials. This study aimed to evaluate the surface microhardness changes of esthetic restorative materials following treatment with aerated beverages in an in-vitro situation. Material and Methods The initial surface microhardness of the restorative materials GC Fuji II LC, GC Fuji IX, Nano Glass ionomer, Resin and Nano composite was re...

  5. Microleakage in primary teeth restored by conventional or bonded amalgam technique.

    Science.gov (United States)

    Myaki, S I; Rodrigues, C R; Raggio, D P; Flores, T A; Matson, M R

    2001-01-01

    The aim of this in vitro study was to evaluate marginal leakage in class V restorations in primary teeth restored with amalgam, using three different techniques. Thirty maxillary anterior primary teeth, clinically sound and naturally exfoliated, were used. In group 1 (n = 10), two thin layers of a copal varnish (Cavitine) were applied. In group 2 (n = 10), Scotchbond Multi-Purpose Plus, a dual adhesive system, was used according to manufacturer instructions. In group 3 (n = 10), One-Step adhesive system in combination with a low-viscosity resin (Resinomer) were used according to manufacturer instructions. All samples were restored with a high-copper dental amalgam alloy (GS 80, SDI). After restoration, the samples were stored in normal saline at 37 degrees C for 72 h. The specimens were polished, thermocycled (500 cycles, 5 degrees and 55 degrees C, 30-s dwell time) and impermeabilized with fingernail polish to within 1.0 mm of the restoration margins. The teeth were then placed in 0.5% methylene blue for 4 h. Finally, the samples were sectioned and evaluated for marginal leakage. The Kruskal-Wallis test showed that the filled adhesive resin (group 3) had the least microleakage. There was no significant difference between groups 1 and 2.

  6. Treatment of abraded teeth using metal free ceramics and conventional metal-ceramic restorations

    Directory of Open Access Journals (Sweden)

    Bošković Mirjana V.

    2012-01-01

    Full Text Available Introduction. Contemporary reconstructive dentistry is considered to be a bioesthetic discipline, the study of the beauty of living creatures in their original form and functions. A discussion of esthetic dentistry, the sophisticated artificial restorations in the patient mouth, hardly discernible to an observer or expert eye, implies a whole series of qualities. Damage of hard tooth-tissue, which is not caused by caries, is a physiological process present throughout the whole life, but some factors can bring about great losses of the hard tissue. This damage can be caused by a combination of different etiological factors, such as genetical and functional ones. Case report. A patient is coming in dental surgery complaining of a large damage of the hard-tooth tissue, ugly appearance of his teeth, speech dysfunction and masticatory problems. An intraoral view shows the presence of a large teeth-abrasion. The treatment plan simplified the treatment with a combination of metal-ceramic restorations and a new ceramic system IPS e.max (Ivoclar Vivadentm Schaan, Liechtenstien. Conclusion. In this clinical case with presented abrasion the treatment was presented using all-ceramic restorations and classical metal-ceramic restorations to establish good health, function and estehetic. The use of restorations based on zirconium (IPS e.max ZirPress, Ivoclar Vivadent, Schaan, Liechtenstein can produce excellent clinical results in the frontal, as well as in lateral segments.

  7. Fluoride release from restorative materials coated with an adhesive.

    Science.gov (United States)

    Miranda, Letícia Algarves; Weidlich, Patrícia; Samuel, Susana Maria Werner; Maltz, Marisa

    2002-01-01

    The retention of both fluoride resins and resin-modified glass ionomer cements to dental tissues can be improved by the association of an adhesive system which promotes the bonding between the resin component and dentin, forming a hybrid layer. The purpose of this investigation was to evaluate if the presence of the adhesive, being part of the hybrid layer composition, interfered with the fluoride released to tooth tissues. The restorative materials studied were: Vitremer (3M), Heliomolar (Vivadent) and Z100 (3M) using an adhesive application (Scotch Bond MultiPurpose Plus--3M). Ten discs of each material were prepared: 5 were covered with the adhesive and 5 were not. The discs were immersed in individual flasks containing artificial saliva which was changed daily. Fluoride release was measured at days 1, 5, 10, 15 and 20 by a fluoride combined electrode (9609 BN--Orion) coupled to an ion analyzer (SA-720 Procyon). One-way ANOVA and the Student-Newman-Keuls test were applied to compare the materials. The results showed that the use of a dental adhesive significantly decreased the fluoride release of Vitremer and reduced the fluoride release of Heliomolar to undetectable levels with the methodology used.

  8. A study on the radiopacity of cavity lining materials for posterior composite resin restoration

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Joo Hoon [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chosun University, Kwangju (Korea, Republic of); Choi, Eui Hwan [Dept. of Conservative Dentistry, College of Dentistry, Chosun University, Kwangju (Korea, Republic of)

    2000-12-15

    The aim of this study was to determine the relative radiopacities of cavity lining materials (Resin-modified Glass Ionomer cement, Compomer and Flowable resin) for posterior composite resin restoration. Resin-modified glass ionomer cement (Fuji II LC, Vitrebond (TM)), Compomers (Dyract , Compoglass, F2000, Dyract(R) flow Compoglass Flow) and Flowable resins (Tetric (R) flow, Aeliteflo (TM) Revolution (TM)) were used. Five specimens of 5 mm in diameter and 2 mm thick were fabricated with each material. Human molars were horizontally sectioned 2 mm thick to include both enamel and dentin. The radiopacities of enamel, dentin, cavity lining materials, aluminum step wedge were obtained from conventional radiograph and NIH image program. All the tested lining materials showed levels of radiopacity the same as or greater than that of dentin. All compomer tested (Dyract (R), Compoglass, F2000, Dyract (R) flow, Compoglass Flow) and Vitrebond (TM), Tetric (R) flow were more radiopaque than enamel. The radiopacities of Fuji II LC and Revolution (TM) were between enamel and dentin and resin-modified glass ionomer cement, Compomer and Tetric (R) flow were greater than those of Revolution (TM), Aeliteflo (TM) or dentin. The level of radiopacity of the tested materials was variable; those with low radiopacity should be avoided in class II restorations, where a clear determination of recurrent caries by the examining clinician could be compromised. Clinician should be able to distinguish these cavity lining materials radiographically from recurrent decay, voids, gaps, or other defects that lead to clinical failure. Utilization of materials ranked more radiopaque than enamel would enable clinicians to distinguish the lining material from tooth structure.

  9. Adhesive dentistry and endodontics: materials, clinical strategies, and procedures for restoration of access cavities: a review.

    Science.gov (United States)

    Schwartz, Richard S; Fransman, Ron

    2011-06-01

    The complexity of restorative dentistry has increased greatly in recent years, with the myriad of products used in "adhesive dentistry." So too has the "simple" matter of restoring access cavities after completion of endodontic treatment. This review discusses current methods of "bonding" to tooth structure, ceramic materials, and metals, with emphasis on those aspects that are important to endodontics. Specific materials, procedures and major decision making elements are discussed, as well as how to avoid problems in compatibility between endodontic and restorative materials.

  10. One year survival of ART and conventional restorations in patients with disability

    NARCIS (Netherlands)

    Molina, G.F.; Faulks, D.; Mazzola, I.; Mulder, J.; Frencken, J.E.F.M.

    2014-01-01

    BACKGROUND: Providing restorative treatment for persons with disability may be challenging and has been related to the patient's ability to cope with the anxiety engendered by treatment and to cooperate fully with the demands of the clinical situation. The aim of the present study was to assess the

  11. Evaluation of cavity wall adaptation of bulk esthetic materials to restore class II cavities in primary molars.

    Science.gov (United States)

    Gaintantzopoulou, Maria D; Gopinath, Vellore K; Zinelis, Spiros

    2017-05-01

    The purpose of the study was to assess the cavity wall adaptation and gap formation of a bulk fill composite resin and reinforced conventional glass ionomer cement and a resin-modified glass ionomer cement in class II restorations on primary molars. Standardized class II slot cavity preparations were prepared in exfoliating primary molars. Teeth were restored with one of the three tested materials (n = 10): SonicFill bulk fill composite resin (SF), EQUIA Fil conventional reinforced glass ionomer cement (EQF), and Vitremer resin-reinforced glass ionomer cement (VT). Cavity wall adaptation of the restorations was investigated by computerized X-ray micro-tomography and the percentage void volume fraction (%VVF) was calculated. Same specimens were sectioned and the interfaces were evaluated by reflection optical microscopy to measure the percentage linear length (%LD) of the interfacial gaps. Samples were further evaluated by environmental scanning electron microscopy (ESEM). EQF and SF showed significantly lower %VVF and %LD values than VT (p materials showed good cavity wall adaptation. Short operating time and good cavity wall adaptation are advantages of the materials in restorative and pediatric dentistry, especially while working on children with limited attention span.

  12. Microhardness of esthetic restorative materials at different depths

    Directory of Open Access Journals (Sweden)

    Palma-Dibb Regina Guenka

    2003-01-01

    Full Text Available The aim of this study was to analyze the microhardness of two resin-modified glass ionomer cements (Vitremer; Fuji II LC; two polyacid-modified composite resins (Freedom; F2000 and a hybrid composite resin (Prodigy, at different depths from the upper surface. Six hemi-cylinders (3 mm height; 3 mm radius per tested material were obtained. Vickers Hardness was determined using a micro-indentation tester. For each hemi-cylinder, three indentations were taken at one of the following depths: 0.4, 1.0, 2.0 and 2.6 mm. For each material, microhardness average was calculated. Statistical analysis was performed using two-way ANOVA and Tukey test Fuji II LC and Vitremer showed no statistically significant difference among hardness means recorded at the four analyzed depths. The hybrid and the polyacid-modified composite resins showed significant decrease microhardness with increasing depth. It may be concluded that for the RMGIC, microhardness was not affected at depths up to 2.6 mm. On the other hand, both hybrid and PMCRs should de better placed in increments not thicker than 2 mm to achieve optimal hardness throughout the restoration.

  13. In silico comparison of the reproducibility of full-arch implant provisional restorations to final restoration between a 3D Scan/CAD/CAM technique and the conventional method.

    Science.gov (United States)

    Mino, Takuya; Maekawa, Kenji; Ueda, Akihiro; Higuchi, Shizuo; Sejima, Junichi; Takeuchi, Tetsuo; Hara, Emilio Satoshi; Kimura-Ono, Aya; Sonoyama, Wataru; Kuboki, Takuo

    2015-04-01

    The aim of this article was to investigate the accuracy in the reproducibility of full-arch implant provisional restorations to final restorations between a 3D Scan/CAD/CAM technique and the conventional method. We fabricated two final restorations for rehabilitation of maxillary and mandibular complete edentulous area and performed a computer-based comparative analysis of the accuracy in the reproducibility of the provisional restoration to final restoration between a 3D scanning and CAD/CAM (Scan/CAD/CAM) technique and the conventional silicone-mold transfer technique. Final restorations fabricated either by the conventional or Scan/CAD/CAM method were successfully installed in the patient. The total concave/convex volume discrepancy observed with the Scan/CAD/CAM technique was 503.50mm(3) and 338.15 mm(3) for maxillary and mandibular implant-supported prostheses (ISPs), respectively. On the other hand, total concave/convex volume discrepancy observed with the conventional method was markedly high (1106.84 mm(3) and 771.23 mm(3) for maxillary and mandibular ISPs, respectively). The results of the present report suggest that Scan/CAD/CAM method enables a more precise and accurate transfer of provisional restorations to final restorations compared to the conventional method. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  14. Classifying dental ceramics: numerous materials and formulations available for indirect restorations.

    Science.gov (United States)

    Helvey, Gregg A

    2014-01-01

    Because there are numerous ceramic systems available to clinicians for all types of indirect restorations, deciding which system works best for a given clinical situation can be a challenge. Understanding the different classifications of ceramic restoratives can be helpful not only to the clinician but also the dental technician. Manufacturers are constantly introducing newer ceramic materials and improving their existing systems, which has resulted in an increase in all-ceramic restorations and fewer porcelain-to-metal restorations. The classification of ceramic materials remains mostly constant; however, it is subject to change based on newer materials and formulations. The classifications of ceramics are described using several different methods.

  15. Comparison of Candida Albicans Adherence to Conventional Acrylic Denture Base Materials and Injection Molding Acrylic Materials

    Directory of Open Access Journals (Sweden)

    Masoomeh Aslanimehr

    2017-03-01

    Full Text Available Statement of the Problem: Candida species are believed to play an important role in initiation and progression of denture stomatitis. The type of the denture material also influences the adhesion of candida and development of stomatitis. Purpose: The aim of this study was comparing the adherence of candida albicans to the conventional and injection molding acrylic denture base materials. Materials and Method: Twenty injection molding and 20 conventional pressure pack acrylic discs (10×10×2 mm were prepared according to their manufacturer’s instructions. Immediately before the study, samples were placed in sterile water for 3 days to remove residual monomers. The samples were then sterilized using an ultraviolet light unit for 10 minutes. 1×108 Cfu/ml suspension of candida albicans ATCC-10231 was prepared from 48 h cultured organism on sabouraud dextrose agar plates incubated at 37oC. 100 μL of this suspension was placed on the surface of each disk. After being incubated at 37oC for 1 hour, the samples were washed with normal saline to remove non-adherent cells. Attached cells were counted using the colony count method after shaking at 3000 rmp for 20 seconds. Finally, each group was tested for 108 times and the data were statistically analyzed by t-test. Results: Quantitative analysis revealed that differences in colony count average of candida albicans adherence to conventional acrylic materials (8.3×103 comparing to injection molding acrylic resins (6×103 were statistically significant (p<0.001. Conclusion: Significant reduction of candida albicans adherence to the injection acrylic resin materials makes them valuable for patients with high risk of denture stomatitis.

  16. Comparison of Candida Albicans Adherence to Conventional Acrylic Denture Base Materials and Injection Molding Acrylic Materials

    Science.gov (United States)

    Aslanimehr, Masoomeh; Rezvani, Shirin; Mahmoudi, Ali; Moosavi, Najmeh

    2017-01-01

    Statement of the Problem: Candida species are believed to play an important role in initiation and progression of denture stomatitis. The type of the denture material also influences the adhesion of candida and development of stomatitis. Purpose: The aim of this study was comparing the adherence of candida albicans to the conventional and injection molding acrylic denture base materials. Materials and Method: Twenty injection molding and 20 conventional pressure pack acrylic discs (10×10×2 mm) were prepared according to their manufacturer’s instructions. Immediately before the study, samples were placed in sterile water for 3 days to remove residual monomers. The samples were then sterilized using an ultraviolet light unit for 10 minutes. 1×108 Cfu/ml suspension of candida albicans ATCC-10231 was prepared from 48 h cultured organism on sabouraud dextrose agar plates incubated at 37oC. 100 μL of this suspension was placed on the surface of each disk. After being incubated at 37oC for 1 hour, the samples were washed with normal saline to remove non-adherent cells. Attached cells were counted using the colony count method after shaking at 3000 rmp for 20 seconds. Finally, each group was tested for 108 times and the data were statistically analyzed by t-test. Results: Quantitative analysis revealed that differences in colony count average of candida albicans adherence to conventional acrylic materials (8.3×103) comparing to injection molding acrylic resins (6×103) were statistically significant (pcandida albicans adherence to the injection acrylic resin materials makes them valuable for patients with high risk of denture stomatitis. PMID:28280761

  17. Use of temporary filling material for index fabrication in Class IV resin composite restoration.

    Science.gov (United States)

    Kim, Kun-Young; Kim, Sun-Young; Kim, Duck-Su; Choi, Kyoung-Kyu

    2013-05-01

    When a patient with a fractured anterior tooth visits the clinic, clinician has to restore the tooth esthetically and quickly. For esthetic resin restoration, clinician can use 'Natural Layering technique' and an index for palatal wall may be needed. In this case report, we introduce pre-restoration index technique on a Class IV defect, in which a temporary filling material is used for easy restoration. Chair-side index fabrication for Class IV restoration is convenient and makes a single-visit treatment possible.

  18. [Adhesion as criterion of choice of materials for dental restorations of defects in cervical area].

    Science.gov (United States)

    Rusanov, F S; Poyurovskaya, I Ya; Krechina, E K; Sogachev, G V

    2015-01-01

    The paper presents the results of comparative in vitro evaluation of classical and flow consistency restorative polymeric materials (Japan and Russia) adhesion to dentin in cervical area. The adhesive properties of these materials were compared with the experimental systems of "sandwich" type, combining layers of classic and flow consistency, glass-ionomer cement Fuji 8 (Japan) and material SMARTCEM 2 (Switzerland). The highest dentin adhesion strength showed Fuji 8, restoration materials of classical consistency proved to have advantage in adhesion properties.

  19. Effects of elevated temperatures on different restorative materials: An aid to forensic identification processes

    Directory of Open Access Journals (Sweden)

    Chetan A Pol

    2015-01-01

    Full Text Available Background: Heat-induced alterations to dental and restorative materials can be of great interest to forensic dentistry. Knowing the specific optical behavior of dental materials can be of high importance as recognition of changes induced by high temperatures can lead to the determination of material which was used in a dental restoration, facilitating identification of burned human remains. Aim: To observe the effects of predetermined temperatures (200°C-400°C-600°C-800°C-1000°C on unrestored teeth and different restorative materials macroscopically and then examine them under a stereomicroscope for the purpose of identification. Materials and Methods: The study was conducted on 375 extracted teeth which were divided into five groups of 75 teeth each as follows: group 1- unrestored teeth, group 2- teeth restored with all-ceramic crowns, Group 3- with class I silver amalgam filling, group 4- with class I composite restoration, and group 5- with class I glass ionomer cement restoration. Results: Unrestored and restored teeth display a series of specific macroscopic & stereomicroscopic structural changes for each range of temperature. Conclusion: Dental tissues and restorative materials undergo a series of changes which correlate well with the various temperatures to which they were exposed. These changes are a consequence of the nature of the materials and their physicochemical characteristics.

  20. Effects of a paste-free prophylaxis polishing cup and various prophylaxis polishing pastes on tooth enamel and restorative materials.

    Science.gov (United States)

    Covey, David A; Barnes, Caren; Watanabe, Hidehiko; Johnson, William W

    2011-01-01

    The application of cleaning and polishing agents to a patient's dentition is a routine part of many dental practices. This study measured the surface roughness and surface gloss of tooth enamel, composite resin, and dental porcelain restorative materials when exposed to a paste-free prophylaxis polishing cup as well as a conventional prophylaxis polishing paste. Samples of human tooth enamel, a composite resin restorative material, and dental porcelain were prepared by a series of polishing papers to produce a flat smooth surface. The baseline average surface roughness (Ra) was measured using a contact stylus profilometer, and the surface gloss was measured with a glossmeter. The test samples were subjected to a standardized polishing routine using a paste-free prophylaxis polishing cup and a fine- or coarse-particle prophylaxis paste. Post-treatment surface roughness and gloss measurements were compared using a paired t statistical test. The conventional prophylaxis pastes increased surface roughness and decreased the gloss of the composite resin and tooth enamel test groups. The paste-free cups did not significantly affect the surface roughness of the enamel or the restorative materials. Dental porcelain surface roughness essentially was not affected by the application of paste-free cups and the fine and coarse pastes.

  1. The Effect of Lucite Glass Reinforcement on the Properties of Conventional Glass-Ionomer Filling Materials

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    Haleh Kazemi Yazdi

    2016-12-01

    Full Text Available Statement of the Problem: The usage of glass ionomer cements (GICs restorative materials are very limited due to lack of flexural strength and toughness. Purpose: The aim of this study was to investigate the effect of using a leucite glass on a range of mechanical and optical properties of commercially available conventional glass ionomer cement. Materials and Method: Ball milled 45μm leucite glass particles were incorporated into commercial conventional GIC, Ketac-Molar Easymix (KMEm. The characteristics of the powder particles were observed under scanning electron microscopy. The samples were made for each experimental group; KMEm and lucite- modified Ketac-Molar easy Mix (LMKMEm according to manufacturer’s instruction then were collected in damp tissue and stored in incubator for 1 hour. The samples were divided into two groups, one stored in distilled water for 24 hours and the others for 1 week.10 samples were made for testing biaxial flexural strength after 1 day and 1 week, with a crosshead speed of 1mm/min, calculated in MPa. The hardness (Vickers hardness tester of each experimental group was also tested. To evaluate optical properties, 3 samples were made for each experimental group and evaluated with a spectrophotometer. The setting time of modified GIC was measured with Gillmore machine. Result: The setting time in LMKMEm was 8 minutes. The mean biaxial flexural strength was LMKMEm/ 1day: 24.13±4.14 MPa, LMKMEm/ 1 week: 24.22±4.87 MPa KMEm/1day:28.87±6.31 MPa and KMEm/1 week: 26.65±5.82 MPa which were not statistically different from each other. The mean Vickers hardness was LMKMEm: 403±66 Mpa and KMEm: 358±22 MPa; though not statistically different from each other. The mean total transmittance (Tt was LMKMEm: 15.9±0.7, KMEm: 22.3±1.2, the mean diffuse transmittance (Td was LMKMEm: 12.2±0.5, KMEm: 18.0±0.5 which were statistically different from each other. Conclusion: Leucite glass can be incorporated with a

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

    Directory of Open Access Journals (Sweden)

    Rodrigo Vieira Caixeta

    2015-01-01

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

  3. Discrimination of tooth layers and dental restorative materials using cutting sounds.

    Science.gov (United States)

    Zakeri, Vahid; Arzanpour, Siamak; Chehroudi, Babak

    2015-03-01

    Dental restoration begins with removing carries and affected tissues with air-turbine rotary cutting handpieces, and later restoring the lost tissues with appropriate restorative materials to retain the functionality. Most restoration materials eventually fail as they age and need to be replaced. One of the difficulties in replacing failing restorations is discerning the boundary of restorative materials, which causes inadvertent removal of healthy tooth layers. Developing an objective and sensor-based method is a promising approach to monitor dental restorative operations and to prevent excessive tooth losses. This paper has analyzed cutting sounds of an air-turbine handpiece to discriminate between tooth layers and two commonly used restorative materials, amalgam and composite. Support vector machines were employed for classification, and the averaged short-time Fourier transform coefficients were selected as the features. The classifier performance was evaluated from different aspects such as the number of features, feature scaling methods, classification schemes, and utilized kernels. The total classification accuracies were 89% and 92% for cases included composite and amalgam materials, respectively. The obtained results indicated the feasibility and effectiveness of the proposed method.

  4. Survival of directly placed ormocer-based restorative materials: A systematic review and meta-analysis of clinical trials.

    Science.gov (United States)

    Monsarrat, Paul; Garnier, Sarah; Vergnes, Jean-Noel; Nasr, Karim; Grosgogeat, Brigitte; Joniot, Sabine

    2017-05-01

    In-vitro experiments on ormocers (ORganically MOdified CERamics) have provided controversial results. Consequently, the objectives of this meta-analysis were to (1) compare clinical performances of first generation ormocers versus conventional composite restorations, (2) explore the influence of various clinical factors and the impact of the quality of studies on published results. The following databases were explored until 2017/01/08: Ovid MEDLINE In-Process, Pubmed, CENTRAL, HTA, DARE, LILACS and Google Scholar. Studies of more than two years with quantitative comparisons between ormocers and control groups were selected. Outcome was the failure of a restoration (need to repair, remove or replace). Multivariate random-effects Poisson's regression was used to obtain a summary estimate. 75% of the 8 included trials concerned Class I/II restorations. Although non-significant, the global failures were higher for ormocers (0.22 [-0.16; 0.61]). For Class I/II restorations, a significantly higher sensitivity was observed for ormocer-based materials compared to other composites (0.75 [0.01; 1.50]). An increase of the number of restorations per patient was associated with higher marginal adaptation failures for ormocers in Class I/II obturations (0.59 [0.11; 1.08]). This study did not identify clear advantages of using the first generation of ormocer-based fillings rather than conventional composites. Given the recent development of new, dimethacrylate-diluent-free ormocer matrices, potentially more stable and resistant, new randomized clinical trials should be developed comparing this new family of pure ormocers with current composites. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. A field-trial of two restorative materials used with atraumatic restorative treatment in rural Turkey: 24-month results

    Directory of Open Access Journals (Sweden)

    Ertugrul Ercan

    2009-08-01

    Full Text Available OBJECTIVE: The purpose of this study was to investigate the clinical performance of high-strength glass ionomer cement (HSGIC and resin-modified glass ionomer (RMGIC in single and multiple surface carious cavities in the field conditions. MATERIAL AND METHODS: A split-mouth design, including ninety-one fillings placed on contra lateral molar pairs of 37 children, was used in permanent dentition. As filling materials, a HSGIC (Ketac Molar/3M ESPE and a RMGIC (Vitremer/ 3M ESPE were used with the Atraumatic Restorative Treatment (ART. Baseline and 6, 12 and 24-month evaluations of the fillings were made with standard-ART and USPHS criteria by two examiners with kappa values of 0.92 and 0.87 for both criteria. RESULTS: According to the USPHS criteria, the retention rates of RMGIC and HSGIC restorations were 100% and 80.9% for single surface, and 100% and 41.2% for multiple surface restorations after 24 months, respectively. Irrespective of surface number, RMGIC was significantly superior to HSGIC (p= 0.004, according to both standard-ART and USPHS criteria. CONCLUSION: The results indicate that RMGIC may be an alternative restorative technique in comparison to high-strength GIC applications in ART-field-trials. However, further clinical and field trials are needed to support this conclusion.

  6. Surface hardness of different restorative materials after long-term immersion in sports and energy drinks.

    Science.gov (United States)

    Erdemir, Ugur; Yildiz, Esra; Eren, Meltem Mert; Ozel, Sevda

    2012-01-01

    The purpose of this study was to evaluate the effect of sports and energy drinks on the surface hardness of different restorative materials over a 6-month period. Forty-two disk-shaped specimens were prepared for each of the four restorative materials tested: Compoglass F, Filtek Z250, Filtek Supreme, and Premise. Specimens were immersed for 2 min daily, up to 6 months, in six storage solutions (n=7 per material for each solution): distilled water, Powerade, Gatorade, X-IR, Burn, and Red Bull. Surface hardness was measured at baseline, after 1 week, 1 month, and 6 months. Data were analyzed statistically using repeated measures ANOVA followed by the Bonferroni test for multiple comparisons (α=0.05). Surface hardness of the restorative materials was significantly affected by both immersion solution and immersion period (p<0.001). All tested solutions induced significant reduction in surface hardness of the restorative materials over a 6-month immersion period.

  7. Influence of dental restorative material properties on bond interface reliability: a finite element analysis

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan-tao; ZHANG Yu-mei; HOU Shu-xun; KONG Liang; LIN Jun; ZHAO Yi-min; HUO Na

    2013-01-01

    Background Varieties of restorative materials are widely used in dentistry.The aim of this study is to explore the influence of different dental restorative materials on bond interface reliability.Methods A two-dimensional finite element analysis method was adopted to simulate the shear-bond efficacy test.The influence of elastic modulus and Poisson's ratio were investigated separately.Several dental restorative materials including resins,metals,and ceramics were analyzed in this study.Results The deformation and peak equivalent stress level of the dentin-adhesive interface rose sharply following a decrease in the elasticity of restorative materials,especially those with a low elastic modulus range.The influence of the Poisson's coefficient was not significant.Ceramics and gold alloy were preferred to resin composite in restorations bearing extensive shear load during service.Conclusions Restorative materials with an elastic modulus similar to that of teeth are not always the best clinical choice.This research provides a helpful guide for the application of different restorative materials in clinical practice.

  8. A comparison of fatigue resistance of three materials for cusp-replacing adhesive restorations.

    NARCIS (Netherlands)

    Kuijs, R.H.; Fennis, W.M.M.; Kreulen, C.M.; Roeters, F.J.M.; Verdonschot, N.J.J.; Creugers, N.H.J.

    2006-01-01

    OBJECTIVES: To investigate the fatigue resistance and failure behaviour of cusp-replacing restorations in premolars using different types of adhesive restorative materials. METHODS: A class 2 cavity was prepared and the buccal cusp was removed in an extracted sound human upper premolar. By using a c

  9. Gold and palladium burden from dental restoration materials.

    Science.gov (United States)

    Drasch, G; Muss, C; Roider, G

    2000-06-01

    From 81 volunteers (16 without dental restorations, 65 with gold crowns or inlays) samples of saliva before and after chewing gum, blood, serum, urine and faeces were taken and analysed for gold (Au) and palladium (Pd). The Au concentration in all analysed biomonitors correlates significantly to the number of teeth with gold restorations. For Pd the correlations were still significant, but weaker than for Au. Persons with gold restorations show maximal Au and Pd concentrations, 10(2)-10(3) higher than the background burden. The calculated maximal daily Au load in saliva (1.38 mg Au per day) reaches the range of an oral Au therapy for rheumatoid arthritis with 6 mg Auranofin (= 1.74 mg Au per day). During this therapy severe and frequent side effects are reported. In contrast, the Au concentration in serum maximally reached from Au restorations, amounts to only approximately 1/20 of the Au level during arthritis therapy. But even under subtherapeutic doses of 1 mg Auranofin/day severe side effects have been reported (4 out of 56 cases). The mean Au blood concentration from 1 mg Auranofin daily was only 3 times higher than our maximum value. A toxicological classification of the Pd values is difficult, because no toxicological threshold limit has been established, especially for the low-level long-term burden with Pd.

  10. Biofilm Formation on Dental Restorative and Implant Materials

    NARCIS (Netherlands)

    Busscher, H. J.; Rinastiti, M.; Siswomihardjo, W.; van der Mei, H. C.

    Biomaterials for the restoration of oral function are prone to biofilm formation, affecting oral health. Oral bacteria adhere to hydrophobic and hydrophilic surfaces, but due to fluctuating shear, little biofilm accumulates on hydrophobic surfaces in vivo. More biofilm accumulates on rough than on

  11. Survival of extensively damaged endodontically treated incisors restored with different types of posts-and-core foundation restoration material.

    Science.gov (United States)

    Lazari, Priscilla Cardoso; de Carvalho, Marco Aurélio; Del Bel Cury, Altair A; Magne, Pascal

    2017-09-16

    analysis (log-rank post hoc test at α=.05 for pairwise comparisons). None of the tested specimen withstood all 140 000 cycles. All specimens without a ferrule were affected by an initial failure phenomenon (wide gap at the lingual margin between the core foundation restoration/crown assembly and the root). NfPfP, NfPt, and NfPtB had similar survival (29649 to 30987 mean cycles until initial failure). NfPfB outperformed NfPt and NfPtB. None of the post-and-core foundation restoration materials were able to match the performance of the ferrule group FPf (72667 cycles). In all groups, 100% of failures were catastrophic. The survival of extensively damaged endodontically treated incisors without a ferrule was slightly improved by the use of a fiber post with a bulk-fill composite resin core foundation restoration. However, none of the post-and-core techniques was able to compensate for the absence of a ferrule. The presence of the posts always adversely affected the failure mode. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  12. Clinical Evaluation of Restorative Materials in Primary Teeth Class II Lesions.

    Science.gov (United States)

    Sengul, F; Gurbuz, T

    2015-01-01

    The aim of this study was to evaluate clinical success of primary teeth class II lesions restored with different restorative materials [Hybrid Composite Resin (HCR), Resin Modified Glass Ionomer Cement (RMGIC), compomer, and Giomer Composite Resin (GCR)] followed up for 24 months. This study was carried out on 146 primary molars of 41 children in the age range of 5-7 years. The class II lesions in primary molars of a patient were restored using different restorative materials. Restorations were evaluated according to FDI-criteria and their survival rates were determined. Data were analysed with Pearson chi-square, Kaplan-Meier and Wilcoxon (Breslow) tests (α = 0.05). The failure rates of restorative materials were as follows: compomer 33.3%, RMGIC 28.1%, HCR 22.5% and GCR 21.1%. While the functional failure was the most important factor in restorative material failure, RMGIC was the most successful material in terms of biological evaluation criterion and GCR had the longest survival rate.

  13. Practitioner, patient and carious lesion characteristics associated with type of restorative material

    DEFF Research Database (Denmark)

    Makhija, Sonia K; Gordan, Valeria V; Gilbert, Gregg H

    2011-01-01

    The authors conducted a study to identify factors associated with the materials that dentists in The Dental Practice-Based Research Network (DPBRN) use when placing the first restoration on permanent posterior tooth surfaces.......The authors conducted a study to identify factors associated with the materials that dentists in The Dental Practice-Based Research Network (DPBRN) use when placing the first restoration on permanent posterior tooth surfaces....

  14. The teaching of all-ceramic restorations in North American dental schools: materials and techniques employed.

    Science.gov (United States)

    Frazier, K B; Mjör, I A

    1997-01-01

    North American dental schools were surveyed to determine the types of clinical experiences and the extent of material use that predoctoral students encounter with restorative procedures that employ all-ceramic materials. The results were based on an overall response rate of 80% from the 64 surveyed schools. The majority (96%) of the 51 schools responding to the survey did offer an opportunity to become experienced with all-ceramic restorations. The selection of bases and liners for all-ceramic restorations included dentin adhesive agents, glass ionomer materials, and calcium hydroxide products, by a ratio of 5:4:1, respectively. The most commonly used impression material types were addition silicone and polyether. One or both of these materials were used by every school. Dicor glass ceramic and alumina core ceramic were the most commonly used materials by the responding schools for veneers, onlays, and crowns. Dicor glass ceramic and CAD/CAM ceramic were most commonly used for inlays. Crowns were made of more different all-ceramic material types than the other restoration classes. Fabrication of all-ceramic restorations was primarily by commercial laboratories and school technicians. Students have hands-on experience in the fabrication of all-ceramic restorations in 6% of the responding schools. Luting agents for all-ceramic restorations include dual-cured resin, in 96% of the responding schools, light-cured resin, 43%, and glass ionomer cement, 33%. Zinc phosphate, chemical-cured composite, and polycarboxylate were used by less than one fourth of the respondents. Only resin-based composite materials were used to lute ceramic veneers. Rubber dam was applied primarily during luting procedures involving all-ceramic inlays and onlays. Crowns and veneers were isolated by this method in less than 30% of the responding schools. Finishing procedures with all-ceramic restorations were accomplished with three or more instruments by 89% of the schools.

  15. Archaeomagnetic studies in Mesoamerica using non-conventional materials

    Science.gov (United States)

    Soler-Arechalde, A.; Gogichaishvili, A.; Urrutia-Fucugauchi, J.

    2004-12-01

    For the first time results of an archaeomagnetic study of mural paintings and unburned lime-plasters from Mesoamerica are presented. The magnetic measurements show that at least four murals (sites: Cacaxtla, Cholula and Templo Mayor) retain a remanent magnetization carried by a mixture of hematite and magnetite grains. In most specimens, a characteristic magnetization is successfully isolated by alternating field demagnetization. The mean directions are reasonably well determined for each murals and within the range of secular variation during the last centuries. Studied Mesoamerican murals apparently retain the direction of the magnetic field at the time they were painted and are therefore an invaluable source of information concerning its secular variation. Lime-plaster samples were selected from two archaeological excavation projects in the Teopancazco residential compound of Teotihuacan and the large multi-stage structure of Templo Mayor in Tenochtitlan, where chronological information is available. The intensity of remanent magnetization and low-field susceptibility are weak reflecting low relative content of magnetic minerals. NRM directions are well grouped and alternating field demagnetization shows single or two-component magnetizations. Rock-magnetic experiments point to fine-grained titanomagnetites with pseudo-single domain behavior. Anisotropy of magnetic susceptibility measurements document a depositional fabric, with normal to free-surface minimum AMS axes. Characteristic mean site directions were correlated to the paleosecular variation curve for Mesoamerica. Our results suggest that archaeomagnetic dating can be applied to mural paintings and lime-plasters, which are materials widely employed in Mesoamerica.

  16. Effect of the lasers used in periodontal therapy on the surfaces of restorative materials.

    Science.gov (United States)

    Hatipoğlu, Mükerrem; Barutcigil, Çağatay; Harorlı, Osman Tolga; Ulug, Bülent

    2016-05-01

    The present study aimed to reveal potential damage of the lasers, which are used as an alternative to manual instruments in periodontal therapy, might cause to the surface of restorative materials. Four different restorative materials were used: a glass-ionomer cement (GIC), a flowable composite (FC), a universal composite (UC) and an amalgam. Ten cylindrical samples (8 mm × 2 mm) were prepared for each restorative material. Two laser systems were used in subgingival curettage mode; an 940 nm diode laser (Epic Biolase, Irvine, CA) and an Er,Cr:YSGG laser (Waterlase iPlus, Biolase, Irvine, CA). After laser irradiation, roughness of the sample surfaces was measured using a profilometer. Additionally, atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses were performed to evaluate the morphology and surface deformations of the restorative materials and surfaces. The laser irradiation did not affect the surface roughness of any restorative materials relative to that of the control group (p > 0.05) except for the Er,Cr:YSGG treatment on GIC (p surface roughness tests. Within the limitations of the present study, it was demonstrated that Er,Cr:YSGG and diode lasers, aside from the Er;Cr:YSGG treatment on GIC, caused no harmful surface effects on adjacent restorative materials. SCANNING 38:227-233, 2016. © 2015 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  17. Effect of whitening toothpastes on bonding of restorative materials to ...

    African Journals Online (AJOL)

    2015-03-26

    Mar 26, 2015 ... Materials and Methods: Eighty labial enamel surfaces of primary incisors were randomly distributed into 8 groups of 10 .... left for 10 min to allow undisturbed interactions of these materials ... testing machine (Instron, model no.

  18. Evidence-based Update of Pediatric Dental Restorative Procedures: Dental Materials.

    Science.gov (United States)

    Dhar, V; Hsu, K L; Coll, J A; Ginsberg, E; Ball, B M; Chhibber, S; Johnson, M; Kim, M; Modaresi, N; Tinanoff, N

    2015-01-01

    The science of dental materials and restorative care in children and adolescent is constantly evolving, and the ongoing search for ideal restorative materials has led to plethora of research. To provide an evidence base to assist dental practitioners choose appropriate restorative care for children and adolescents. This evidence-based review appraises this literature, primarily between the years 1995-2013, for efficacy of dental amalgam, composites, glass ionomer cements, compomers, preformed metal crowns and anterior esthetic restorations. The assessment of evidence for each dental material was based on a strong evidence, evidence in favor, expert opinion, and evidence against by consensus of the authors. There is varying level of evidence for the use of restorative materials like amalgam, composites, glass ionomers, resin-modified glass-ionomers, compomers, stainless steel crowns and anterior crowns for both primary and permanent teeth. A substantial amount data is available on restorative materials used in pediatric dentistry; however, there exists substantial evidence from systematic reviews and randomized clinical trials and clinicians need to examine and understand the available literature evidence carefully to aid them in clinical decision making.

  19. NEW TECHNOLOGIES FOR RESTORATION AND PROTECTION OF POWER EQUIPMENT WITH THE AID OF COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    A. O. Ischenko

    2017-01-01

    Full Text Available The analysis of possible variants of reconstruction of the power equipment is fulfilled and the conclusion concerning the prospects of such work with the use of composite materials is reached. The data on the technical characteristics of composite repair materials for various purposes are presented, the results of repairs of power equipment, in particular the technology for the recovery of the boarding surfaces of the diffuser rings and protection of the pumps D1250 casings are provided. The technology of the recovery pneumatic cylinder, hydraulic cylinder rod, as well as the unique technology of restoration of working surfaces of the impeller vanes of transfer pump, that had been destroyed by corrosion in conjunction with the cavitation processes and were considered as not restorable is described. The restored impeller was in operation during a year and only thereafter it was removed for restoration. Another composite material discussed in the article – diagum – makes it possible to perform a series of repairs associated with restoration of the rubber-covered surfaces of pump casings as well as with restoration of various surfaces of the conveyor belts. Taking the excellent adhesive properties of this composite into account, restoration of worn stainless steel sieve screens to remove abrasive material was fulfilled with the aid of it. The restoration was accomplished via the use of the conveyor belt which application time had expired, that was glued to a metal sieve with diagum. The use of the composites is economically justified, because the application of them in repairs reduces, firstly, terms of restoration work and, secondly, the price of repairs. Third, equipment that was damaged beyond repair is being commissioned by the use of the mentioned composites. 

  20. In Vitro Inhibition of Enamel Demineralisation by Fluoride-releasing Restorative Materials and Dental Adhesives.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Koliniotou-Koumpia, Eugenia; Helvatzoglou-Antoniades, Maria; Kotsanos, Nikolaos

    2016-01-01

    To determine the ability of 5 contemporary fluoride-releasing restoratives and 3 fluoride-releasing adhesives to inhibit enamel demineralisation surrounding restorations, and the associations between inhibition and the levels of fluoride released from these materials. Five fluoride-releasing restoratives (Fuji IX GP, Ketac N100, Dyract Extra, Beautifil II and Wave) and 3 fluoride-releasing adhesives (Stae, Prime & Bond NT and Fluoro Bond II) were investigated. Eight disks of each material were prepared. Fluoride release was measured daily using a fluoride-ion-selective electrode for 15 days. Twenty-four cavities for each group were restored with a restorative and an adhesive. Specimens were subjected to thermal stress and stored for 30 days in saline solution. After a 15-day pH-cycling regimen, two 150-μm-thick sections were derived from each specimen. Enamel lesion depth was measured at 0, 100, and 200 μm from each restoration's margin via polarised light microscopy. Of the restoratives investigated, Fuji IX GP released the most fluoride. The fluoride-releasing restoratives tested exhibited shallower enamel lesions than did the control group at all distances tested (p enamel lesion depth than did the other experimental materials. The depths of enamel lesions did not differ significantly when comparing restoratives applied with a fluoride-releasing adhesive with those applied with a non-fluoride-releasing adhesive. The fluoride-releasing materials tested reduced enamel demineralisation but to different extents, depending on their levels of fluoride release. Fluoride-releasing adhesives did not influence enamel lesion formation.

  1. Repeated exposure of acidic beverages on esthetic restorative materials: An in-vitro surface microhardness study.

    Science.gov (United States)

    Xavier, Arun M; Sunny, Steffy M; Rai, Kavita; Hegde, Amitha M

    2016-07-01

    A manifold increase in the consumption of aerated beverages has witnessed a twin increase in tooth wear and raised demand for esthetic restorative materials. This study aimed to evaluate the surface microhardness changes of esthetic restorative materials following treatment with aerated beverages in an in-vitro situation. The initial surface microhardness of the restorative materials GC Fuji II LC, GC Fuji IX, Nano Glass ionomer, Resin and Nano composite was recorded. These materials were studied under 3 groups that included those exposed to the acidic beverages daily, weekly once in a month and those that had no exposures at all. The final surface microhardness of the materials was recorded following experimentation and was subjected to statistical comparisons. The restorative materials were compared for their surface microhardness changes following respective treatments using the T-test and One-way ANOVA analysis. Inter-comparisons between the groups showed statistical significance (pmaterials revealed surface microhardness loss; the maximum reduction noticed with the Nano glass ionomer cement tested (pmaterials markedly reduced upon repeated exposures with acidic beverages; the product with phosphoric acid producing the maximum surface microhardness loss. Restorative materials, acidic beverages, surface microhardness, resin composites, glass ionomers.

  2. Assessment of marginal stability and permeability of an interim restorative endodontic material.

    Science.gov (United States)

    Kazemi, R B; Safavi, K E; Spångberg, L S

    1994-12-01

    The purpose of this study was to assess the marginal stability and permeability of a new interim restorative endodontic material, Tempit (Centrix Inc., Milford, Conn.), and to compare the findings with the results of two commonly used restorative endodontic materials, Cavit (Premier Dental Products Co., Philadelphia, Pa.) and IRM (Intermediate Restorative Material Capsules, The Caulk Co., Division of Dentsply International Inc., Milford, Del.) This study was performed in several steps. First, the endodontic access cavities were prepared and restored on 80 extracted mandibular molars. The samples were exposed to methylene blue dye solution for 6 days, thermocycled, and sectioned; the dye penetration and diffusion were measured along the margins and into the body of the materials. The second experiment was a special study performed in standardized glass tubes to better evaluate the marginal and body dye penetration into the materials by increasing the length of the fillings. To eliminate the possibility of hygroscopic setting mechanisms of materials, samples were first allowed to set under water before dye was introduced. Cavit and Tempit showed a substantial amount of dye diffusion into the body of the materials. Cavit exhibited the best sealing ability at all times. The marginal and body dye penetration were significantly different for the Tempit material in all experiments than Cavit (p IRM demonstrated the least body penetration of all three materials (p material (p = 0.6 and p = 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Influence of Curing Units and Indirect Restorative Materials on the Hardness of Two Dual-curing Resin Cements Evaluated by the Nanoindentation Test.

    Science.gov (United States)

    Kuguimiya, Rosiane Noqueira; Rode, Kátia Martins; Carneiro, Paula Mendes Acatauassú; Aranha, Ana Cecilia Corrêa; Turbino, Miriam Lacalle

    2015-06-01

    To evaluate the hardness of a dual-curing self-adhesive resin cement (RelyX U200) and a conventional dual-curing resin cement (RelyX ARC) cured with different light curing units of different wavelengths (Elipar Freelight 2 LED [430 to 480 nm, conventional], Bluephase LED [380 to 515 nm, polywave], AccuCure 3000 Laser [488 nm]) by means of the nanoindentation test. Bovine incisors were cleaned and then sectioned at the cementoenamel junction to remove the crown. After embedding in acrylic, dentin surfaces of the specimens were exposed and ground flat to standardize the surfaces. To simulate clinically placing indirect restorations, ceramic (IPS e.maxPress/Ivoclar Vivadent) or indirect composite resin (SR Adoro/Ivoclar Vivadent) slabs were cemented on dentin surfaces. The specimens were sectioned longitudinally at low speed under constant irrigation and then polished. In the positive control group, the cement was light cured without the interposition of indirect restorative material; in the negative control group, after the indirect restorative material was cemented, no light curing was performed, allowing only chemical polymerization of the cement. All specimens were stored in distilled water at 37°C for 7 days. Nanoindentadion hardness of the cement layer was measured under a 100-mN load. Data were statistically analyzed using ANOVA and Tukey's test (p < 0.05). Although the self-adhesive cement is technically simple, conventional cement showed the best polymerization performance. The polywave LED technology did not differ significantly from other light-curing units. The hardness of the resin cements evaluated was negatively influenced by the interposition of an indirect restorative material; only the LEDs were able to maintain the same degree of cement polymerization when an indirect restorative material was used. The photoactivation step is required during the cementation of indirect restorations to ensure adequate polymerization of dual-curing resin cements.

  4. A useful and non-invasive microanalysis method for dental restoration materials

    Science.gov (United States)

    Hosoki, M.; Satsuma, T.; Nishigawa, K.; Takeuchi, H.; Asaoka, K.

    2012-12-01

    The elemental analysis of intraoral dental restorations provides considerable information for the treatment of dental metal allergy. Elemental analyses require specific instruments and complicated procedures, so this examination is not commonly carried out in private dental clinics. We describe a novel, simple and useful micro-analytical method for dental metal restorations. Micro metal dust was obtained by polishing the surface of restorative metal material with an unused silicone point (SUPER-SNAP). The metal dust on the silicone point was then rubbed onto adhesive tape, and this tape was covered with polyethylene film. The amount of metal dust material was <20 μg. An energy dispersive X-ray fluorescence spectrometer was used to carry out the elementary analysis of the metal dust on the polyethylene film. Three types of dental metal alloy materials of known components were examined. The results of elementary analyses were compared with the specifications provided by the manufacturer. The same procedure was carried out for three dental metal restorations of an adult female volunteer in vivo. The results of elemental analyses for five alloy materials exactly matched the product specification. Three metal samples obtained from intraoral restoration were also available for elemental analyses. The distinct advantage of this method is that it enables sample extraction without an invasive effect for the restoration. The metal sample is in a polyethylene film, so it is easy to mail it for inspection at specialist institutes yet it can be also be used in general dental clinics.

  5. Influence of photo-activation source on enamel demineralization around restorative materials

    Directory of Open Access Journals (Sweden)

    Juliana de Oliveira Ferla

    2013-06-01

    Full Text Available This study evaluated the effects of the photoactivation source and restorative material on the development of caries-like lesions on human enamel after an in vitro pH challenge. Enamel cavities were prepared in 36 blocks, which were assigned to two groups according to the restorative material: resin-modified glass ionomer (RMGI and composite resin (CR. Samples were exposed to quartz-tungsten-halogen lamp, argon-ion laser, or light-emitting diode (n = 6. The Knoop microhardness (KHN values of the top surface of all materials were evaluated. Restored enamel blocks were thermocycled and subjected to 10 demineralization-remineralization cycles at 37°C. KHN analysis of the superficial enamel was performed by four indentations located 100 mm from the restoration margin. The material KHN was not affected by the photoactivation source. No significant difference in KHN was noted between CR and RMGI. The enamel surface around RMGI exhibited a higher KHN (272.8 KHN than the enamel around CR (93.3 KHN, regardless of the photoactivation source. Enamel demineralization around the dental restoration was not influenced by the photoactivation source. Less enamel demineralization was observed around the RMGI than around the CR restoration.

  6. The effect of polishing systems on microleakage of tooth coloured restoratives: Part 1. Conventional and resin-modified glass-ionomer cements.

    Science.gov (United States)

    Yap, A U; Tan, S; Teh, T Y

    2000-02-01

    The purpose of this in vitro study was to investigate the effect of polishing systems on the microleakage of conventional and resin-modified glass-ionomer cements. Class V cavities were prepared at the cemento-enamel junction of 80 freshly extracted posterior teeth. The prepared teeth were randomly divided into two groups and restored with conventional or resin-modified glass-ionomer cements. The restored teeth were stored in distilled water at 37 degrees C for 1 week after removal of excess restorative with diamond finishing burs. The restored teeth were then divided into four groups of 10 and finished and polished using the following systems: Two Striper MFS; Sof-Lex XT; Enhance Composite Finishing and Polishing System; Shofu Composite Finishing Kit. The finished restorations were subjected to dye penetration testing. Results showed that the microleakage at dentin margins of conventional glass-ionomer cements and enamel margins of resin-modified glass-ionomer cements are significantly affected by the different polishing systems.

  7. Forensic applications: Fluorescence properties of tooth-coloured restorative materials using a fluorescence DSLR camera.

    Science.gov (United States)

    Kiran, Ramya; Walsh, Laurence J; Forrest, Alexander; Tennant, Marc; Chapman, James

    2017-02-03

    The objective of this study was to compare the fluorescence properties of dry and wet samples of contemporary tooth-coloured restorative materials using a fluorescence based DSLR camera and a variety of LEDs emitting different wavelengths of visible light as excitation sources. The materials examined included resin composites; ceramics and hybrid restorative materials such as ormocers, Vita Enamic™ and resin reinforced glass-ionomer cements. The levels of fluorescence for each sample under different combinations of incident light wavelengths and filters was analysed by using histogram data for colour channels from Adobe Photoshop software. Fluorescence patterns were influenced by water sorption of the materials. UV-A/Violet light (405±nm) produced the greatest range of luminosity values (10-204) amongst the tooth-coloured restorative materials, and showed the greatest differences between restorations and tooth structure. The best filter combinations with violet light were orange or yellow filters. Under ultraviolet excitation, Fuji VIII A2 exhibited a unique bright pink fluorescence emission, while VitaEnamic™, ormocer and glass-ionomer cements emitted bluish-pink fluorescence emissions. In conclusion, restorative materials exhibited varied emission pattern under UV-A (405nm) light, which enables their detection and differentiation from natural tooth structure.

  8. Effect of finishing technique on the microleakage and surface texture of resin-modified glass ionomer restorative materials.

    Science.gov (United States)

    Wilder, A D; Swift, E J; May, K N; Thompson, J Y; McDougal, R A

    2000-07-01

    The purpose of this study was to evaluate the effects of wet and dry finishing/polishing procedures on the microleakage and surface texture of resin-modified glass ionomer (RMGI) restorative materials. Class V cavity preparations were made at the cemento-enamel junction (CEJ) on the buccal and lingual surface of 30 extracted human molars. The teeth were restored in three groups of 10 (20 preparations in each group) using Fuji II LC and Vitremer, both RMGIs, and Fuji II, a capsulated conventional glass ionomer cement (control). One restoration per tooth was finished/polished with copious applications of water and the other was finished/polished without water. All restorations were finished/polished using a sequence of four abrasive disks. Finishing/polishing was initiated according to manufacturers' instructions-immediately after light-curing Fuji II LC and Vitremer, and 15min after placement for Fuji II. The specimens were thermocycled and subjected to a silver nitrate leakage test. Each tooth was sectioned buccolingually and examined with an optical microscope at 40x to determine the extent of microleakage at enamel and dentin margins. The data were subjected to a non-parametric statistical analysis. To evaluate surface roughness after polishing, three disks each of Vitremer and Fuji II LC were fabricated in Teflon molds. One disk of each material was not finished/polished (control). The others were finished/polished using Sof-Lex abrasive disks. One specimen of each material was kept wet during all finishing/polishing procedures, while the other was kept dry. Atomic force microscopy was used to determine the average roughness (R(a)) of the specimens. For each material, microleakage at the enamel margin was very slight. Leakage of the conventional glass ionomer Fuji II was severe at dentin margins. Statistical analysis indicated that both Vitremer and Fuji II LC had significantly less leakage than Fuji II, and that Vitremer had significantly less leakage than Fuji

  9. Informatics systems to assess and apply clinical research on dental restorative materials.

    Science.gov (United States)

    Anusavice, K J

    2003-12-01

    Dental biomaterials are used clinically for one or more of the following purposes: to restore function, to enhance esthetics, and to prevent or arrest demineralization of tooth structure. Studies of the clinical performance of restorations and prostheses made from these materials have generally focused on quality assessment and survival statistics. Data from these studies should provide probabilities of specific treatment outcomes that are useful for practicing dentists. However, the utility of these data is limited by the lack of national and international standards for assessing these clinical outcomes. Standardized approaches toward clinical informatics and treatment-decision analysis are urgently needed to minimize the variability of clinical outcomes reported in publications associated with direct and indirect restorative materials used for dental restorations and prostheses.

  10. A six-year prospective randomized study of a nano-hybrid and a conventional hybrid resin composite in Class II restorations

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2013-01-01

    The objective of this 6 year prospective randomized equivalence trial was to evaluate the long-term clinical performance of a new nano-hybrid resin composite (RC) in Class II restorations in an intraindividual comparison with its well-established conventional hybrid RC predecessor....

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

    Science.gov (United States)

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

    2016-01-01

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

  12. Methods to achieve the effect of «dry shine» of composite restorative materials

    OpenAIRE

    Mekhtieva R.R.; Nelovko T.V.; Eremin O.V.; Zaitseva E.M.; Ivashchenko Y.Y.

    2013-01-01

    The purpose: to determine the most effective method and sequence of polishing systems to achieve the effect of «dry light» of the final restoration ofthevestibular surface of the incisors and molars chewing surface of the hybrid light-cured composite materials. Material and methods. Material for polishing for the restoration divided into three groups: 1. Grinding discs — firm TOR VM with three types of grit: coarse, medium, soft and super soft, firm 3M ESPE «Sof-Lex» ultrafine polishing wheel...

  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. [Exploration of basic restorative dental materials teaching in the field of dental technology].

    Science.gov (United States)

    Jin, Yan-ting

    2012-12-01

    This study was to compare the difference of the existing course materials of basic restorative dental with the past materials, found out the weakness of teaching mode before the reform, and explored the reform in education through teaching content, method and evaluation, in order to improve the teaching quality.

  15. Effect of antibacterial varnishes applied to root dentin on shear bond strength of tooth-colored restorative materials.

    Science.gov (United States)

    Korkmaz, Yonca; Baseren, Meserret

    2008-01-01

    This study investigated the effect of certain varnishes on the bond strength of different tooth-colored restorative materials applied to root dentin. One-hundred and eighty tooth slabs, including mesial and distal surfaces, were attained through dividing the teeth, then embedding them in methylmethacrylate. The root surfaces were ground flat through cementum, exposing the dentin. The samples were then randomly divided into three main groups: Group 1: Cervitec; Group 2: Fluor Protector and Group 3: No applications (control). Cervitec and Fluor Protector were applied to the root dentin surfaces according to the manufacturer's instructions. All the samples were kept in artificial saliva for six months. Each main group was subdivided into five groups of 12 teeth each: Group A: Flowable Resin Composite (Grandio Flow); Group B: Microhybrid Resin Composite (Artemis); Group C: Polyacid Modified Resin Composite (Dyract Extra); Group D: Resin Modified Glass Ionomer Cement (Vitremer) and Group E: Conventional Glass-Ionomer Cement (Ionofil Molar). Restorative materials were applied to the root dentin surfaces using a cylindrical mold. After thermocycling (1000 cycles, 5 degrees C/55 degrees C, dwell time 30 seconds), the shear bond strength of the restored samples was determined by a universal testing machine (Zwick Test Machine, Zwick GmbH & Co, Ulm, Germany) at a 5 mm/minute crosshead speed. Failure mode was determined under a stereomicroscope. The data were evaluated statistically by using one-way Analysis of Variance and Duncan tests (p< or =0.05). In the fluoride varnish group, all of the restorative materials except for Ionofil Molar, showed lower bond strengths when compared to the control group (p<0.05). In the Cervitec group, Artemis and Dyract Extra showed lower bond strengths; whereas, Ionofil Molar showed a higher bond strength than the control group (p<0.05). The highest percentage of cohesive fracture was observed in Artemis and Dyract Extra in the control group.

  16. Effect of cariogenic biofilm challenge on the surface hardness of direct restorative materials in situ.

    Science.gov (United States)

    Barbosa, Renata Pereira de Sousa; Pereira-Cenci, Tatiana; Silva, Wagner Missio da; Coelho-de-Souza, Fabio Herrmann; Demarco, Flávio Fernando; Cenci, Maximiliano Sérgio

    2012-05-01

    The presence of cariogenic biofilm could result in surface degradation of composite and ionomeric restorative materials. Thus, this study evaluated in situ the alterations in the surface microhardness of these materials under biofilm accumulation and cariogenic challenge. In a split-mouth, double-blind, cross-over study, 10 volunteers wore palatal intra-oral devices containing bovine enamel slabs restored with composite resin (CR - Z250) or resin-modified glass ionomer (RMGI - Vitremer). Two phases of 14 days were carried out, one for each restorative material. In one side of the device, biofilm was allowed to accumulate under a plastic mesh, whereas in the opposing side, regular brushing was carried out 3 times/day with a dentifrice containing 1100 μg F/g as NaF. A 20% sucrose solution was applied extra-orally 10×/day on each restored dental slab. Knoop microhardness was used to calculate the percentage of surface hardness loss (%SHL). All materials showed a decrease in surface hardness after the in situ period. The restorative materials presented the following average for %SHL: RMGI without biofilm accumulation=8.9 and with biofilm accumulation=25.6, CR without biofilm accumulation=14.7 and with biofilm accumulation=17.0. Biofilm accumulation and the presence of cariogenic challenge promoted faster degradation of ionomeric materials, but this was not observed for composite resin. The oral environment affects the surface hardness of aesthetic restorative materials. Biofilm accumulation and cariogenic challenge promote surface degradation for ionomeric materials, but not for composite resin. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Biofilm formation on dental restorative and implant materials.

    Science.gov (United States)

    Busscher, H J; Rinastiti, M; Siswomihardjo, W; van der Mei, H C

    2010-07-01

    Biomaterials for the restoration of oral function are prone to biofilm formation, affecting oral health. Oral bacteria adhere to hydrophobic and hydrophilic surfaces, but due to fluctuating shear, little biofilm accumulates on hydrophobic surfaces in vivo. More biofilm accumulates on rough than on smooth surfaces. Oral biofilms mostly consist of multiple bacterial strains, but Candida species are found on acrylic dentures. Biofilms on gold and amalgam in vivo are thick and fully covering, but barely viable. Biofilms on ceramics are thin and highly viable. Biofilms on composites and glass-ionomer cements cause surface deterioration, which enhances biofilm formation again. Residual monomer release from composites influences biofilm growth in vitro, but effects in vivo are less pronounced, probably due to the large volume of saliva into which compounds are released and its continuous refreshment. Similarly, conflicting results have been reported on effects of fluoride release from glass-ionomer cements. Finally, biomaterial-associated infection of implants and devices elsewhere in the body is compared with oral biofilm formation. Biomaterial modifications to discourage biofilm formation on implants and devices are critically discussed for possible applications in dentistry. It is concluded that, for dental applications, antimicrobial coatings killing bacteria upon contact are more promising than antimicrobial-releasing coatings.

  18. Use of lining materials under posterior resin composite restorations in the UK.

    Science.gov (United States)

    Blum, Igor R; Younis, Nadeem; Wilson, Nairn H F

    2017-02-01

    To investigate opinions on, and current use of lining materials prior to the placement of posterior resin composite restorations by general dental practitioners (GDPs) in the UK. A further objective was to investigate aspects of posterior resin composite restoration placement techniques employed by UK GDPs. A questionnaire was devised to gain the information sought. It was sent to 500 UK dentists, chosen at random from the register of the General Dental Council. Three hundred and fifty four replies were received, which gave a response rate of 71%. Eighty two percent of respondents reported placing lining materials in deep cavities to be restored with resin composite. Regarding moderately deep cavities, half of the respondents indicated a preference to place a lining material, whilst 44% were not sure if a lining was required. The remaining 6% did not respond to the question. Of the respondents, 39% reported that they did not place lining materials in shallow cavities. Regarding techniques for posterior resin composite placement, two-step etch and rinse systems were the most common adhesive bonding systems used (60%). The majority of respondents (80%) reported not using rubber dam when restoring posterior teeth with resin composite. There was considerable confusion about the need to place a lining prior to resin composite restorations placement in moderate depth and shallow cavities, whilst most favoured the placement of a lining in deep posterior cavities. The majority of GDPs may not routinely use rubber dam for the placement of posterior resin composite restorations. Decision making and operative techniques for cavity linings under posterior composite restorations in moderately deep and deep cavities is contentious among dentists, resulting in a need to generate more convincing, practice-relevant data on the use of lining materials to inform the dental profession. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Clinical Evaluation and Early Finishing of Glass Ionomer Restorative Materials

    Science.gov (United States)

    1988-01-01

    material reported in this study compare fa- present after 9 30 7 23 vorably with a study by Timmons, Laswell , and Robinson (1983) of eight composite...R W (1978) "ji TIMMONS, J H. LASWELL , H R & ROBINSON, F B (1983) A in vitro study of certain properties of a glass ionomer three-year clinical study

  20. Effect of polishing on the microleakage of three different restorative materials: An in vitro study

    Directory of Open Access Journals (Sweden)

    Arnab Sengupta

    2014-01-01

    Full Text Available Aims and Objectives: The purpose of this in vitro study was to investigate the effect of polishing systems on the microleakage of three different restorative materials (Ketac Molar Easymix, Ketac N100 and Filtek P90. Materials and Methods: Class V cavities were prepared at the cemento-enamel junction of 60 freshly extracted premolars. The prepared teeth were randomly divided into three groups and restored with the three materials. The restored teeth were stored in distilled water at 37°C for 1 week. The restored teeth were then divided into two subgroups (polished and not polished of 10. Finishing and polishing of the polished group was done using the Sof-Lex polishing system. Furthermore, all the restorations were subjected to dye penetration testing. Results: Results showed that maximum microleakage was observed for the not polished group of Filtek P90 and least levels of microleakage were seen for the polished group of Ketac Molar Easymix. Conclusion: There was a significant difference seen when Ketac Molar Easymix was compared with Ketac N100 and Filtek P90 in terms of the extent of microleakage exhibited on polishing of the three materials; with the former exhibiting the least microleakage scores.

  1. Effects of plaque disclosing agents on esthetic restorative materials used in pediatric dentistry.

    Science.gov (United States)

    Hino, Débora Maki; Mendes, Fausto Medeiros; de Figueiredo, José Luiz Guimarães; Gomide, Katya Luce Moura Naves; Imparato, José Carlos Pettorossi

    2005-01-01

    The aim of study was to evaluate the color stability of tooth-colored restorative materials usually used in pediatric dentistry after the application of two plaque disclosing agents. Twenty specimens of each material: a resin-modified glass ionomer, a composite resin and an ion-releasing composite resin, were prepared. Baseline color evaluation was performed, samples were exposed to the plaque disclosing agents: a basic fuchsin solution and a fluorescent dye, and new color evaluations were made. The resin-modified glass ionomer stained with basic fuchsin presented the greatest color change in the present study, and the fluorescent dye did not show statistically significant changes among the restorative materials. In conclusion, basic fuchsin dyes should be carefully used in children with a great number of tooth-colored restorations.

  2. A comparison of the dimensional accuracy of microwave and conventionally polymerized denture base materials.

    Science.gov (United States)

    Harrison, A; Huggett, R; Zissis, A; Vowles, R W

    1993-01-01

    This study compares the dimensional changes of microwave and conventionally polymerized denture bases and also establishes the degree of monomer conversion using gas-liquid chromatography. Dimensional changes of three denture base materials were assessed using an optical comparator and the results showed no significant differences between the materials employed or the curing method used. Efficient monomer conversion was demonstrated with levels of residual monomer of less than 1% for all materials.

  3. Effect of prophylactic polishing protocols on the surface roughness of esthetic restorative materials.

    Science.gov (United States)

    Neme, A L; Frazier, K B; Roeder, L B; Debner, T L

    2002-01-01

    Many polishing protocols have been evaluated in vitro for their effect on the surface roughness of restorative materials. These results have been useful in establishing protocols for in vivo application. However, limited research has focused on the subsequent care and maintenance of esthetic restorations following their placement. This investigation evaluated the effect of five polishing protocols that could be implemented at recall on the surface roughness of five direct esthetic restorative materials. Specimens (n=25) measuring 8 mm diameter x 3 mm thick were fabricated in an acrylic mold using five light-cured resin-based materials (hybrid composite, microfilled composite, packable composite, compomer and resin-modified glass ionomer). After photopolymerization, all specimens were polished with Sof-Lex Disks to produce an initial (baseline) surface finish. All specimens were then polished with one of five prophylactic protocols (Butler medium paste, Butler coarse paste, OneGloss, SuperBuff or OneGloss & SuperBuff). The average surface roughness of each treated specimen was determined from three measurements with a profilometer (Surface 1). Next, all specimens were brushed 60,000 times at 1.5 Hz using a brush-head force of 2 N on a Manly V-8 cross-brushing machine in a 50:50 (w/w) slurry of toothpaste and water. The surface roughness of each specimen was measured after brushing (Surface 2) followed by re-polishing with one of five protocols, then final surface roughness values were determined (Surface 3). The data were analyzed using repeated measures ANOVA. Significant differences (p=0.05) in surface roughness were observed among restorative materials and polishing protocols. The microfilled and hybrid resin composite yielded significantly rougher surfaces than the other three materials following tooth brushing. Prophylactic polishing protocols can be used to restore a smooth surface on resin-based esthetic restorative materials following simulated tooth

  4. In vitro evaluation of fracture strength of zirconia restoration veneered with various ceramic materials

    OpenAIRE

    Choi, Yu-Sung; Kim, Sung-Hun; Lee, Jai-Bong; Han, Jung-Suk; Yeo, In-Sung

    2012-01-01

    PURPOSE Fracture of the veneering material of zirconia restorations frequently occurs in clinical situations. The purpose of this in vitro study was to compare the fracture strengths of zirconia crowns veneered with various ceramic materials by various techniques. MATERIALS AND METHODS A 1.2 mm, 360° chamfer preparation and occlusal reduction of 2 mm were performed on a first mandibular molar, and 45 model dies were fabricated in a titanium alloy by CAD/CAM system. Forty-five zirconia copings...

  5. Physical Property Investigation of Contemporary Glass lonomer and Resin Modified Glass lonomer Restorative Materials

    Science.gov (United States)

    2016-05-24

    fracture toughness. vi Manuscript Introduction The optimal dental restorative material would be biocompatible, demonstrate adhesion to tooth material...10 GICs are self- adhesive materials that bond to tooth hard tissues through chemica l bonding to dental hard tissues, 11 as the ionic bond between...Colonel Michael N. Wajdowi Dean, Air Fo rce Postgraduate Dental School Acknowledgements Special thanks to Col Howard Roberts, Col Michael Wajdowicz

  6. Shear Bond Strength of Ormocer-Based Restorative Material Using Specific and Nonspecific Adhesive Systems

    OpenAIRE

    Hamouda, Ibrahim M.; Shehata, Salah H.

    2011-01-01

    The aim of this study was to evaluate the shear bond strength of ormocer-based restorative material bonded to tooth structure using specific ormocer and nonspecific resin-based adhesives. Human molars were prepared to obtain flat buccal enamel surfaces and flat occlusal dentin surfaces. Admira bond, and Prime & Bond NT, Excite, AdheSE, and Prompt-L-Pop were applied to the prepared enamel and dentin surfaces. Ormocer restorative material was inserted into a mold fixed onto the prepared tooth s...

  7. Adhesion of oral streptococci to all-ceramics dental restorative materials in vitro.

    Science.gov (United States)

    Meier, R; Hauser-Gerspach, I; Lüthy, H; Meyer, J

    2008-10-01

    In recent years, patients have benefited from the development of better and more esthetic materials, including all-ceramics dental restorative materials. Dental plaque formation on teeth and restorative materials plays an important role in the pathogenesis of oral diseases. This study investigates initial adhesion of stationary phase streptococcal species to different all-ceramics dental restorative materials. The saliva-coated materials were incubated with the bacteria for 1 h in an in vitro flow chamber which mimics environmental conditions in the oral cavity. Number and vitality of adhering bacteria were determined microscopically after staining. Surface roughness and the composition of the materials had no distinctive influence on bacterial adhesion. However, S. mutans and S. sobrinus adhered about tenfold less numerous to all materials than the other streptococcal species. Further, there was a correlation between bacterial vitality and materials' glass content. The results showed that early plaque formation was influenced predominantly by the presence of the salivary pellicle rather than by material dependent parameters whereas the composition of the all-ceramics appeared to have influenced the percentage of viable cells during the adhesion process. This presented in vitro technique may provide a useful model to study the influence of different parameters on adherence of oral streptococcal species.

  8. Trends in material choice for posterior restorations in an Israeli dental school: composite resin versus amalgam.

    Science.gov (United States)

    Ben-Gal, Gilad; Weiss, Ervin I

    2011-12-01

    According to a recent American Dental Association survey, posterior composite resin restorations now outnumber amalgam restorations in the United States. Dental schools around the world vary considerably in the extent to which they teach the use of composite resins. We aimed to determine if there has been an increase in the placement of posterior composite restorations in an Israeli dental school and if faculty experience affects the type of posterior restoration placed. In this retrospective study, we recorded and analyzed all the restorations performed by undergraduate students in the last five academic years at the Hebrew University Hadassah School of Dental Medicine in Jerusalem. All clinical records of student treatments between 2004 and 2009 were screened, and direct restorations were registered. Out of 6,094 posterior restorations performed during the study period, 42.3 percent were made of composite resin, increasing from 36.8 percent in 2004-05 to 48.5 percent in 2008-09, an increase of 11.7 percent. When clinical instructors were asked to state their preference if they themselves were to undergo posterior restoration, similar results were obtained. Instructors with less than ten years' experience preferred posterior composite resin restorations in 54.8 percent of the hypothetical situations, compared with 37.2 percent preferred by instructors with ten years of experience or more. It appears that the use of composite resin was influenced mainly by the prevailing trend and was not based on scientific evidence. Dental faculties should define criteria, based on up-to-date clinical studies, for using new materials, taking into consideration differences among instructors regarding treatment concept.

  9. Restoration of endodontically treated anterior teeth: an evaluation of coronal microleakage of glass ionomer and composite resin materials.

    Science.gov (United States)

    Diaz-Arnold, A M; Wilcox, L R

    1990-12-01

    A glass ionomer material was evaluated for coronal microleakage in permanent lingual access restorations of endodontically treated anterior teeth. The material was tested as a restoration, placed over a zinc oxide-eugenol base, and as a base with an acid-etched composite resin veneer and a dentinal bonding agent. Restored teeth were thermocycled, immersed in silver nitrate, developed, and sectioned to assess microleakage. Significant coronal leakage was observed with all materials used.

  10. Surface roughness of restorative materials after immersion in mouthwashes

    Directory of Open Access Journals (Sweden)

    Lauren Oliveira Lima Bohner

    2016-01-01

    Full Text Available Objective: To evaluate the surface roughness of resin composite and ceramic material after immersion in mouthwashes. Methodology: Thirty specimens of resin composite and ceramic material were prepared with a stainless steel matrix (6 mm × 2 mm. The samples of each material were divided into three groups (n = 10, according to the mouthwashes: Distilled water (DW, chlorhexidine (CL 0.12%, and cetylpyridinium chloride (CC. Specimens were individually submitted to the immersion cycle in 15 mL of mouthwash for 30 days, three times per day, for 1 min/cycle. Surface roughness measurements were performed at three different time intervals: Before the first cycle (T0, after 7 (T1, and 30 days (T2 of immersion. Data were analyzed by the two-way ANOVA and Tukey tests (P ≤ 0.05. Results: There was no statistically significant difference in surface roughness of resin composite among mouthwashes (DW - 1.4 ± 0.13 μm; CL - 1.16 ± 0.13 μm; CC - 1.18 ± 0.13 μm. Surface roughness was statistically significantly lower after 30 days (T2-0.56 ± 0.60 μm compared with the initial period (T0-1.63 ± 0.60 μm and after 7 days (T1-1.57 ± 0.60 μm. For ceramic material, CC (3.75 ± 0.60 μm caused a higher level of surface roughness compared with DW (2.57 ± 0.60 μm and CL (3.39 ± 0.60 μm. There was no statistically significant difference among the different time intervals (T0-3.05 ± 0.18 μm; T1-3.41 ± 0.18 μm; T2-3.26 ± 0.18 μm. Conclusion: Mouthwashes did not promote a significant change in surface roughness of composite resin. Cetylpyridinium chloride promoted an increase in surface roughness of dental ceramic.

  11. Fracture Resistance of Endodontically Treated Maxillary Premolars Restored by Various Direct Filling Materials: An In Vitro Study

    Science.gov (United States)

    Mincik, Jozef; Timkova, Silvia; Urban, Renata

    2016-01-01

    The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars (n = 64) with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each: group A intact teeth, group B unfilled cavity, group C composite made by oblique layering technique, group D composite with 2 mm cusp coverage, group E bulk-filled posterior composite, group F glass-ionomer, group G amalgam, and group H composite with proximal boxes. The specimens were subjected to an axial compression load with the mean values of fracture resistance in group A: 1289 N, group B: 181.75 N, group C: 445.38 N, group D: 645.88 N, group E: 355.13 N, group F: 352.00 N, group G: 191.38 N, and group H: 572.00 N. There was no significant difference between groups B and G, between C and D, E, and F, and between group D and H. All other measurements were statistically significant. We conclude that composite restoration with cusp coverage is the most ideal nonprosthetic solution for endodontically treated teeth. Cusp coverage increases the fracture resistance compared to the conventional cavity design. PMID:27656212

  12. A useful and non-invasive microanalysis method for dental restoration materials

    Energy Technology Data Exchange (ETDEWEB)

    Hosoki, M., E-mail: hosoki@tokushima-u.ac.jp [Department of Fixed Prosthodontics, Institute of Health Biosciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8504 (Japan); Satsuma, T.; Nishigawa, K.; Takeuchi, H. [General Dentistry, Tokushima University Hospital, 3-18-15 Kuramoto-cho, Tokushima 770-8504 (Japan); Asaoka, K. [Department of Biomaterials and Bioengineering, Institute of Health Biosciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8504 (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer This method for the microanalysis of dental alloys is beneficial for patients with allergies to dental materials. Black-Right-Pointing-Pointer This metal sample is easy to mail it for inspection at specialist institutes. Black-Right-Pointing-Pointer This method can be also be used in general dental clinics. - Abstract: The elemental analysis of intraoral dental restorations provides considerable information for the treatment of dental metal allergy. Elemental analyses require specific instruments and complicated procedures, so this examination is not commonly carried out in private dental clinics. We describe a novel, simple and useful micro-analytical method for dental metal restorations. Micro metal dust was obtained by polishing the surface of restorative metal material with an unused silicone point (SUPER-SNAP). The metal dust on the silicone point was then rubbed onto adhesive tape, and this tape was covered with polyethylene film. The amount of metal dust material was <20 {mu}g. An energy dispersive X-ray fluorescence spectrometer was used to carry out the elementary analysis of the metal dust on the polyethylene film. Three types of dental metal alloy materials of known components were examined. The results of elementary analyses were compared with the specifications provided by the manufacturer. The same procedure was carried out for three dental metal restorations of an adult female volunteer in vivo. The results of elemental analyses for five alloy materials exactly matched the product specification. Three metal samples obtained from intraoral restoration were also available for elemental analyses. The distinct advantage of this method is that it enables sample extraction without an invasive effect for the restoration. The metal sample is in a polyethylene film, so it is easy to mail it for inspection at specialist institutes yet it can be also be used in general dental clinics.

  13. Effect of polishing on the microleakage of three different restorative materials: an in vitro study.

    Science.gov (United States)

    Sengupta, Arnab; Gupta, Anil; Dagur, Renu

    2014-01-01

    The purpose of this in vitro study was to investigate the effect of polishing systems on the microleakage of three different restorative materials (Ketac Molar Easymix, Ketac N100 and Filtek P90). Class V cavities were prepared at the cemento-enamel junction of 60 freshly extracted premolars. The prepared teeth were randomly divided into three groups and restored with the three materials. The restored teeth were stored in distilled water at 37°C for 1 week. The restored teeth were then divided into two subgroups (polished and not polished) of 10. Finishing and polishing of the polished group was done using the Sof-Lex polishing system. Furthermore, all the restorations were subjected to dye penetration testing. Results showed that maximum microleakage was observed for the not polished group of Filtek P90 and least levels of microleakage were seen for the polished group of Ketac Molar Easymix. There was a significant difference seen when Ketac Molar Easymix was compared with Ketac N100 and Filtek P90 in terms of the extent of microleakage exhibited on polishing of the three materials; with the former exhibiting the least microleakage scores.

  14. Quantification of Staphylococcus aureus adhesion forces on various dental restorative materials using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Merghni, Abderrahmen, E-mail: abderrahmen_merghni@yahoo.fr [Laboratoire des Maladies Transmissibles et Substances biologiquement actives (LR99ES27) Faculté de Pharmacie de Monastir, Université de Monastir (Tunisia); Kammoun, Dorra [Laboratoire de Biomatériaux et Biotechnologie, Faculté de Médecine Dentaire, Monastir (Tunisia); Hentati, Hajer [Laboratoire de Recherche en Santé Orale et Réhabilitation Bucco-Faciale (LR12ES11), Faculté de Médecine Dentaire de Monastir, Université de Monastir (Tunisia); Janel, Sébastien [BioImaging Center Lille-FR3642, Lille (France); Popoff, Michka [Cellular Microbiology and Physics of Infection-CNRS UMR8204, INSERM U1019, Institut Pasteur de Lille, Lille University (France); Lafont, Frank [BioImaging Center Lille-FR3642, Lille (France); Cellular Microbiology and Physics of Infection-CNRS UMR8204, INSERM U1019, Institut Pasteur de Lille, Lille University (France); Aouni, Mahjoub [Laboratoire des Maladies Transmissibles et Substances biologiquement actives (LR99ES27) Faculté de Pharmacie de Monastir, Université de Monastir (Tunisia); Mastouri, Maha [Laboratoire des Maladies Transmissibles et Substances biologiquement actives (LR99ES27) Faculté de Pharmacie de Monastir, Université de Monastir (Tunisia); Laboratoire de Microbiologie, CHU Fattouma Bourguiba de Monastir (Tunisia)

    2016-08-30

    Highlights: • 4 dental restorative materials were characterized for roughness, angle contact water and surface free energy. • AFM adhesion forces of S. aureus to tested materials were achieved in presence and absence of salivary conditioning film. • S. aureus initial adhesion is dependent on the surface free energy and roughness. - Abstract: In the oral cavity dental restorative biomaterials can act as a reservoir for infection with opportunistic Staphylococcus aureus pathogen, which can lead to the occurrence of secondary caries and treatment failures. Our aim was to evaluate the adhesion forces by S. aureus on four dental restorative biomaterials and to correlate this finding to differences in specific surface characteristics. Additionally, the influence of salivary conditioning films in exerted adhesion forces was investigated. The substrate hydrophobicity was measured by goniometer and the surface free energy was calculated using the equilibrium advancing contact angle values of water, formamide, and diiodomethane on the tested surfaces. The surface roughness was determined using atomic force microscope (AFM). Additionally, cell force spectroscopy was achieved to quantify the forces that drive cell-substrate interactions. S. aureus bacterium exerted a considerable adhesion forces on various dental restorative materials, which decreased in the presence of saliva conditioning film. The influence of the surface roughness and free energy in initial adhesion appears to be more important than the effect of hydrophobicity, either in presence or absence of saliva coating. Hence, control of surface properties of dental restorative biomaterials is of crucial importance in preventing the attachment and subsequent the biofilm formation.

  15. Effect of cyclic loading on the bond strength of class II restorations with different composite materials.

    Science.gov (United States)

    Cavalcanti, Andrea Nóbrega; Mitsui, Fabio Hiroyuki Ogata; Silva, Flávia; Peris, Alessandra Rezende; Bedran-Russo, Ana; Marchi, Giselle Maria

    2008-01-01

    This study evaluated the effect of cyclic loading on the bond strength of Class II restorations using different composite materials. Class II preparations with gingival margins located in dentin were performed on the mesial surface of 80 bovine incisors. The teeth were randomly allocated to eight groups (n=10) according to resin composite (Filtek Z250, Filtek Supreme, Tetric Ceram HB and Esthet-X) and use of cyclic loading. The restorations were bonded with the Single Bond adhesive system. Simulated aging groups were cyclic loaded for 200,000 cycles with 80N load (2Hz). The specimens were vertically sectioned (two slabs per restoration) and further trimmed into an hour-glass shape at the adhesive interface to obtain a final bonded area 1 mm2. Samples were placed in an apparatus and tested under tension using a universal testing machine. The data were analyzed using two-way ANOVA and Tukey test with a 95% confidence level. Aged groups presented significantly lower means when compared to the groups that were not aged (p=0.03). However, significant differences among composite materials were not observed (p=0.17). Regardless of the restorative composite material used, it could be concluded that the bond strength of Class II restorations at the gingival wall was affected by simulated cyclic loading.

  16. Comparison of microleakage from stainless steel crowns margins used with different restorative materials: An in vitro study

    Directory of Open Access Journals (Sweden)

    Mahtab Memarpour

    2016-01-01

    Conclusion: When SSC margins overlaid the restoration materials, cavity restoration with amalgam or GI before SSC placement led to less microleakage and material loss. Regarding microleakage and material loss, resin-based composite, zinc phosphate, and Zonalin were not suitable options.

  17. In vitro electrical impedance spectroscopy of human dentine: the effect of restorative materials.

    Science.gov (United States)

    Rivas, Berta; Botta, Pablo M; Varela, Purificación; Martín, Benjamín; Fondado, Alfonso; Rivas, Jose

    2008-04-01

    The influence of different restorative materials on in vitro dielectric properties of sound dentine was investigated. The studied samples were three-layer materials consisting of successive disks of dentine and silver amalgam or nanohybrid composite resin. Before being tested, the samples were maintained in physiological solution never more than 48 h from the extraction. Also, sections of intact dentine were similarly prepared for electrical measurements. Complex dielectric permittivity of these specimens was determined in a wide frequency range using the parallel-plate capacitor technique. Very similar dielectric responses of intact dentine and amalgam-dentine material were observed. This is explained on the basis of high dc conductivity exhibited by both samples. In contrast, resin-dentine specimen revealed a much more insulating behavior. A simple theoretical model for heterogeneous systems could be applied to these dental three-layer materials. The dielectric properties of restored dentine are strongly dependent on the kind of restorative material employed in each case. This suggests that electrical data should be used carefully in caries diagnosis on restored teeth.

  18. Effect of Soft Drinks and Fresh Fruit Juice on Surface Roughness of Commonly used Restorative Materials.

    Science.gov (United States)

    Maganur, Prabhadevi; Satish, V; Prabhakar, A R; Namineni, Srinivas

    2015-01-01

    In this in vitro study, the effects of a Cola drink, and fresh fruit juice (citrus) on the surface roughness on flowable composite and resin-modified glass ionomer cement (RMGIC) each was evaluated and compared. Using a brass mold 70 pellets each of flowable composite (Filtek™ Flow) and RMGIC tricure restorative material were prepared according to the manufacturer's instructions. Two groups (groups I and II) were formed containing 30 pellets of each material. Remaining 10 pellets of each restorative material did form the control group [water (group III)]. Experimental group pellets were again divided into three subgroups (mild, moderate and severe) containing 10 pellets each and were kept in plastic containers with 30 ml Cola drink (group I) and fresh fruit juice (group II) respectively. Immersion regime was followed according to M aupome G et al. Baseline and final surface roughness (Ra) value for each pellet was evaluated using a profilometer. Statistical analysis was done with Wilcoxon's signed rank test and analysis of variance (ANOVA) followed by Mann-Whitney test. Results showed that the erosive effect of both Cola drink and fresh fruit juice caused significant surface roughness on both flowable composite and RMGIC restorative materials in the mild, moderate and severe immersion regimes. How to cite this article: Maganur P, Satish V, Prabhakar AR, Namineni S. Effect of Soft Drinks and Fresh Fruit Juice on Surface Roughness of Commonly used Restorative Materials. Int J Clin Pediatr Dent 2015;8(1):1-5.

  19. Fluoride release and recharge abilities of contemporary fluoride-containing restorative materials and dental adhesives.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Koliniotou-Koumpia, Eugenia; Helvatzoglou-Antoniades, Maria; Kotsanos, Nikolaos

    2013-01-01

    The aim of this study was to evaluate the fluoride release of five fluoride-releasing restorative materials and three dental adhesives, before and after NaF solution treatment. Five restorative materials (Fuji IX GP, GC Corp.; Ketac N100, 3M ESPE; Dyract Extra, Dentsply; Beautifil II, Shofu Inc.; Wave, SDI) and three dental adhesives (Stae, SDI; Fluorobond II - Shofu Inc.; Prime & Bond NT, Dentsply) were investigated before and after NaF solution treatment. A fluoride ion-selective electrode was to measure fluoride concentrations. During the 86-day period before NaF solution treatment, Fuji IX GP released the highest amount of fluoride among the restorative materials while Prime & Bond NT was the highest among the dental adhesives. After NaF solution treatment, Fuji IX GP again ranked the highest in fluoride release among the restorative materials while Fluorobond II ranked the highest among dental adhesives. It was concluded that the compositions and setting mechanisms of fluoride-containing dental materials influenced their fluoride release and recharge abilities.

  20. Fracture resistance of endodontically treated teeth restored with Zirconia filler containing composite core material and fiber posts

    Science.gov (United States)

    Jeaidi, Zaid Al

    2016-01-01

    Objectives: To assess the fracture resistance of endodontically treated teeth with a novel Zirconia (Zr) nano-particle filler containing bulk fill resin composite. Methods: Forty-five freshly extracted maxillary central incisors were endodontically treated using conventional step back preparation and warm lateral condensation filling. Post space preparation was performed using drills compatible for fiber posts (Rely X Fiber Post) on all teeth (n=45), and posts were cemented using self etch resin cement (Rely X Unicem). Samples were equally divided into three groups (n=15) based on the type of core materials, ZirconCore (ZC) MulticCore Flow (MC) and Luxacore Dual (LC). All specimens were mounted in acrylic resin and loads were applied (Universal testing machine) at 130° to the long axis of teeth, at a crosshead speed of 0.5 mm/min until failure. The loads and the site at which the failures occurred were recorded. Data obtained was tabulated and analyzed using a statistical program. The means and standard deviations were compared using ANOVA and Multiple comparisons test. Results: The lowest and highest failure loads were shown by groups LC (18.741±3.02) and MC (25.16±3.30) respectively. Group LC (18.741±3.02) showed significantly lower failure loads compared to groups ZC (23.02±4.21) and MC (25.16±3.30) (pcomposite cores was comparable to teeth restored with conventional Zr free bulk fill composites. Zr filled bulk fill composites are recommended for restoration of endodontically treated teeth as they show comparable fracture resistance to conventional composite materials with less catastrophic failures. PMID:28083048

  1. EFFECTS OF POLISHING TIME AND THERMALCYCLINGON THE MICROLEAKAGE OF FOUR TOOTH –COLOURED DIRECT RESTORATIVE MATERIALS

    Directory of Open Access Journals (Sweden)

    V MORTAZAVI

    2002-09-01

    Full Text Available Introdaction. Microleakage has been recognized as a major clinical problem with direct filled dental restorations.The purpose of this study was to investigate and to compare the microleakage of four direct filled tooth-coloured materials, evaluation the effects of polishing time and thermocycling on the microleakage of these materials. Methods. Wedge-shaped class V cavities were prepared on buccal and lingual surfaces of 96 intact extracted human molar teeth. The teeth were randomly divided into three treatment groups and four subgroups. The cavities of each subgroup were filled using one of these materials: a conventional glass ionomer; a resin modified glass ionomer; a composite resin and a compomer. Polishing in the teeth of group 1 was done immediately after placement of restorations and in group 2 one week later. In group 3 delayed polishing and thermocycling (X100 was done. All of the teeth were stored in distilled water for one week and then stained with dye, sectioned, and scored for microleakage on occlusal and cervical edges. Results were statistically analyzed by Kruskal wallis and Mann whitney tests. Results. There was a statistically difference between the microleakage scores of four materials (P < 0.001. Immediately polished glass ionomer and compomer groups have significantly more microleakage than delayed polished groups (P < 0.001. Thermocycting could infulence the microleakage of composite on cervical edges (P < 0.05. Discussion. The precense of differences between the nature of materials and also the surface treatment such as primer or etchant application could influence the microleakage. The prescence of differences in reaction rate between the materials and the time that they reach to their adequate mechanical strength and adhesive bond strength lead to presence of differences between the effect of polishing time on the microleakage scores of materials.

  2. In vitro Comparative Evaluation of Various Restorative Materials used for restoring Class III Cavities in Deciduous Anterior Teeth: A Clinical Study.

    Science.gov (United States)

    Priyank, Harsh; Verma, Ankita; Gupta, Komal; Chaudhary, Esha; Khandelwal, Deepak; Nihalani, Shweta

    2016-12-01

    Beauty standards in today's modernized world scenario are formed by well-aligned and well-designed bright white teeth. One of the major reasons behind patients reporting to dental clinics is pain. Caries in the anterior primary teeth forms one of the major concerns from a restorative point of view. Very few studies are quoted in literature which stresses on the follow-up of anterior restorations in primary teeth. Hence, we evaluated and compared the efficacy of composite resin and resin-modified glass ionomer cement (RGIC) for class III restorations in primary anterior teeth. The present study was conducted in the pediatric dental wing and included a total of 80 patients aged 3 to 5½ years who reported with the chief complaint of carious lesions in the primary anterior teeth. Patients having minimal of a pair of similar appearing small carious lesions on the same proximal surfaces of the deciduous maxillary incisors were included for the study. All the patients were randomly divided into two groups: One in which RGIC restoration was done and other in which composite restoration was done. Cavity preparation was done and filling of the cavity with the restorative materials was carried out. Assessment of the restorations was done at 4, 8, and 12 months time following criteria given by Ryge et al. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software. Mann-Whitney test and one-way analysis of variance (ANOVA) were used to evaluate the level of significance; p value less than 0.05 was considered as significant. For composite and RGIC restorations, the mean score for anatomic shape was 1.21 and 1.10 respectively. While comparing the clinical parameters, nonsignificant results were obtained between composite and RGIC restorative materials at 4-, 8-, and 12-month interval. On comparing the clinical parameters for individual restorative materials at different time intervals, statistically significant results were obtained only for

  3. In vitro comparative evaluation of mechanical properties of temporary restorative materials used in fixed partial denture.

    Science.gov (United States)

    Saisadan, D; Manimaran, P; Meenapriya, P K

    2016-10-01

    Materials used to fabricate provisional restorations can be classified as acrylics or resin composites. Provisional crows can be either prefabricated or custom made. These materials have been used to fabricate provisional restorations since the 1930s and usually available as powder and liquid. They are the most commonly used materials today for both single-unit and multiple-unit restorations. In general, their popularity is due to their low cost, acceptable esthetics, and versatility. Composite provisional materials use bis-acryl resin, a hydrophobic material that is similar to bis-GMA. Composites are available as auto-polymerized, dualpolymerized and visible light polymerized. Preformed provisional crowns or matrices usually consist of tooth-shaped shells of plastic, cellulose acetate or metal. They are commercially available in various tooth sizes and are usually selected for a particular tooth anatomy. They are commonly relined with acrylic resin to provide a more custom fit before cementation, but the plastic and metal crown shells can also be cemented directly onto prepared teeth. The aim of this study is to choose a material to serve as a better interim prosthesis and to compare three different properties - flexural strength, compressive strength, and color stability. The samples were made with three different provisional materials (Revotek LC, Protemp 4, TemSpan). It was inferred from the study that no one material was superior in all three tested parameters.

  4. Comparative evaluation of secondary caries formation around light-cured fluoride-releasing restorative materials

    Directory of Open Access Journals (Sweden)

    N Sathyajith Naik

    2017-01-01

    Full Text Available Aim: The aim of this study was to compare and evaluate secondary caries formation around light-cured fluoride-releasing restorative materials. Methodology: Standard Class V cavities were prepared on the buccal and lingual surfaces of forty extracted healthy premolars. The teeth were randomly divided into four groups of ten teeth each and labeled as Group I, II, III, and IV and restored with one of the following materials, namely, Fuji II LC (Group I, Vitremer (Group II, F-2000 (Group III, and Z-100 (Group IV; Control. The teeth were thermocycled and immersed in jars containing an acid gel for caries-like lesion formation. After 15 weeks, the samples were removed, washed, and sectioned buccolingually through the restoration. The sections were then grounded to a thickness of 80–100 µm. After imbibition in water, the sections were mounted on slides and lesions were examined, measured, and photographed with Leica DMRB Research Microscope. The observation recorded was subjected to (a analysis of variance, (b Studentized range test (Newman–Keuls, (c Snedecor's F-test. Results: The depth of the outer lesion in teeth restored with Z-100 (Group IV; Control was significantly higher than the teeth restored with F-2000 (Group III, Vitremer (Group II, and Fuji II LC (Group I (P < 0.01. The depth of the outer lesion in teeth restored with F-2000 (Group III was also significantly higher than the teeth restored with Vitremer (Group II and Fuji II LC (Group I (P < 0.01. However, there was no significant difference in depth of the outer lesions among the teeth restored with Vitremer (Group II and Fuji II LC (Group I. No wall lesion (WL was evident in teeth restored with Vitremer (Group II and Fuji II LC (Group I. The WL length and body depth in teeth restored with Z-100 (Group IV; Control were significantly higher than the teeth restored with F-2000 (Group III (P < 0.01. Conclusion: It was concluded that Fuji II LC and Vitremer had a inhibitory effect on the

  5. A new classification system for all-ceramic and ceramic-like restorative materials.

    Science.gov (United States)

    Gracis, Stefano; Thompson, Van P; Ferencz, Jonathan L; Silva, Nelson R F A; Bonfante, Estevam A

    2015-01-01

    Classification systems for all-ceramic materials are useful for communication and educational purposes and warrant continuous revisions and updates to incorporate new materials. This article proposes a classification system for ceramic and ceramic-like restorative materials in an attempt to systematize and include a new class of materials. This new classification system categorizes ceramic restorative materials into three families: (1) glass-matrix ceramics, (2) polycrystalline ceramics, and (3) resin-matrix ceramics. Subfamilies are described in each group along with their composition, allowing for newly developed materials to be placed into the already existing main families. The criteria used to differentiate ceramic materials are based on the phase or phases present in their chemical composition. Thus, an all-ceramic material is classified according to whether a glass-matrix phase is present (glass-matrix ceramics) or absent (polycrystalline ceramics) or whether the material contains an organic matrix highly filled with ceramic particles (resin-matrix ceramics). Also presented are the manufacturers' clinical indications for the different materials and an overview of the different fabrication methods and whether they are used as framework materials or monolithic solutions. Current developments in ceramic materials not yet available to the dental market are discussed.

  6. Effect of preheating on the film thickness of contemporary composite restorative materials

    Directory of Open Access Journals (Sweden)

    Dimitrios Dionysopoulos

    2014-12-01

    Conclusion: The film thickness of the composites tested is material dependent. The thickness of the preheated conventional composites is significantly lower than those at room temperature. The conventional composites provide film thickness values greater than those of the flowable composites regardless of preheating temperature.

  7. In vitro comparison of coronal microleakage of four temporary restorative materials used in endodontic treatment

    Directory of Open Access Journals (Sweden)

    Shahi Sh.

    2008-10-01

    Full Text Available "nBackground and Aim: The use of proper temporary restorative materials between appointments is critical in successful root canal treatment. The purpose of this study was to compare the coronal microleakage of four temporary restorative materials including Zonalin, Zamherir, Coltosol and IRM. "nMaterials and Methods: In this in vitro study, standard access cavities were prepared in 120 intact extracted maxillary and mandibular human first molars. Canal preparation was carried out by the step-back technique, and obturation was performed with gutta-percha and AH26 sealer using the lateral condensation technique. Teeth were randomly divided into 4 experimental groups of 25 teeth each and two positive and negative control groups, each containing 10 teeth. In each experimental group the access cavity was restored with one of the tested materials (Zamherir, Zonalin, IRM and Coltosol. In the negative control group the access cavity was filled entirely with sticky wax and in the positive control group no restorative material was applied. Dye penetration technique was used to evaluate microleakage which was measured under a stereomicroscope. Data were analyzed with one way ANOVA and post hoc Tukey tests. P<0.05 was considered as the limit of significance. "nResults: Dye penetration was observed in all groups. Zonalin and Coltosol had the highest and the lowest dye penetration respectively, with a statistically significant difference (p<0.001. There was no significant difference in dye penetration between IRM, and either Coltosol or Zamherir (p>0.05. "nConclusion: The results of this study showed that using Coltosol as a temporary restorative material can provide a better coronal seal in endodontic treatments

  8. Development of North American forb plant materials for rangeland revegetation and restoration

    Science.gov (United States)

    Plant materials development for Intermountain rangelands is a primary mission of the USDA-ARS Forage and Range Research Laboratory. Currently there is a significant demand for North American forbs (including legumes) for rangeland revegetation and restoration in the Great Basin, but commercial quan...

  9. POLYTETRAFLUOROETYLENE TAPE AS TEMPORARY RESTORATIVE MATERIAL: A FLUID FILTRATION STUDY ⃰

    Directory of Open Access Journals (Sweden)

    Keziban Olcay

    2015-10-01

    Full Text Available Purpose: The purpose of this study was to compare the sealing ability of temporary restorative materials at 24 hrs and 1 week. Materials and Methods: Endodontic access cavities were prepared in 56 extracted lower incisor-teeth and divided into 5 groups (n=10. Standard 5 mm deep access preparations were completed and root canals were prepared to size ISO #30 file. The access cavities were restored as follows: Group 1: temporary restorative material (Ceivitron; Group 2: glass ionomer cement (Fuji II; Group 3: zinc oxide-eugenol cement (IRM; Group 4: zinc phosphate cement (Adhesor; Group 5: polytetrafluoroetylene tape (PTFE. The quality of the coronal sealing of each specimen was measured (24 hrs and 1 week using fluid transport model. The data was analysed with repeated measurements of ANO VA, Tukey, Paired samples T-Tests. Results: A significant difference was found among the groups at all time-periods (p0.05. Sealing ability of IRM and PTFE groups significantly increased by time (p<0.05 and p<0.001 respectively. Conclusion: Within the limitations of this study, PTFE showed an acceptable short-term sealing capability when compared to the other commonly used temporary restorative materials at 1 week measurements.

  10. Graphite immobilisation in iron phosphate glass composite materials produced by microwave and conventional sintering routes

    Energy Technology Data Exchange (ETDEWEB)

    Mayzan, M.Z.H. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia); Stennett, M.C.; Hyatt, N.C. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Hand, R.J., E-mail: r.hand@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2014-11-15

    An investigation of microwave and conventional processing of iron phosphate based graphite glass composite materials as potential wasteforms for the immobilisation of irradiated graphite is reported. For the base iron phosphate glass, full reaction of the raw materials and formation of a glass melt occurs with consequent removal of porosity at 8 min microwave processing. When graphite is present, iron phosphate crystalline phases are formed with higher levels of residual porosity than in the sample prepared using conventional sintering under argon. It is found that graphite reacts with the microwave field when in powder form but this reaction is minimised when the graphite is incorporated into a pellet, and that the graphite also impedes sintering of the glass. Mössbauer spectroscopy indicates that reduction of iron also occurs with concomitant graphite oxidation. Conventionally sintered samples had lower porosities than the equivalent microwaved ones.

  11. Thermal Properties of Contemporary and Conventional Gutta Percha Materials Used in Root Canal Treatment

    Science.gov (United States)

    2015-01-15

    HQWU\\LQWKLVEORFNLVQHFHVVDU\\LI WKHDEVWUDFWLVWREHOLPLWHG FINAL TECHNICAL REPORT Thermal Properties of Contemporary and Conventional Gutta...been extensively described in the scientific literature . 1-22 The gutta-percha polymer, trans-polyisoprene, can exist in two crystalline and/or...clinical technique. Furthermore, some literature has suggested that not all commercially available endodontic gutta-percha materials exist in the same

  12. Effect of cyclic loading on fracture strength of endodontically treated teeth restored with conventional and esthetic posts

    National Research Council Canada - National Science Library

    Anuar Antônio Xible; Rudys Rodolfo de Jesus Tavarez; Carlos dos Reis Pereira de Araujo; Paulo César Rodrigues Conti; Wellington Cardoso Bonachella

    2006-01-01

    ...: This study compared the effect of cyclic loading on survival rate, residual strength and mode of fracture of endodontically treated teeth restored with esthetic and direct metallic post systems...

  13. RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

  14. Comparative study on stiffness properties of WOODCAST and conventional casting materials.

    Science.gov (United States)

    Pirhonen, Eija; Pärssinen, Antti; Pelto, Mika

    2013-08-01

    Plaster-of-Paris and synthetic materials (e.g. fibreglass) have been in clinical use as casting materials for decades. An innovative casting material, WOODCAST, brings interesting alternatives to the traditional materials. The aim of this study was to compare the stiffness properties of the WOODCAST material to traditional casting materials. In immobilization by casting, materials with variable stiffness properties are required. Ring stiffness of cylindrical samples correlates well with cast rigidity. For load-bearing structures, the use of the WOODCAST Splint is recommended as equally high stiffness was obtained with the WOODCAST Splint as was with fibreglass. The WOODCAST 2 mm product is optimal for structures where some elasticity is required, and WOODCAST Ribbon can be used in any WOODCAST structure where further reinforcement is needed. The results show that WOODCAST material can be used in replacing traditional casting materials used in extremity immobilization. The mechanical properties of casting material play an important role in safe and effective fracture immobilization. Stiffness properties of the WOODCAST casting material and conventional materials - fibreglass and plaster-of-Paris - were analysed in this study. The WOODCAST Splint appears to compare favorably with traditional materials such as Scotchcast.

  15. Longevity of silicate ceramic restorations.

    Science.gov (United States)

    Beier, Ulrike Stephanie; Dumfahrt, Herbert

    2014-09-01

    The demand for esthetic restorations has resulted in an increased use of dental ceramics as a biocompatible and functionally sufficient alternative to conventional restorative materials. Silicate ceramic restorations are widely used for veneers, inlays, onlays, and crowns in dentistry. Long-term data are of crucial importance to optimize clinical practice. The purpose of the present article is to summarize data of the Innsbruck ceramic evaluation up to 261 months with the focus on longevity and failure characteristics.

  16. Comparative evaluation of microleakage between bulk esthetic materials versus resin-modified glass ionomer to restore Class II cavities in primary molars

    Directory of Open Access Journals (Sweden)

    Vellore Kannan Gopinath

    2017-01-01

    Full Text Available Aim: The aim of the study was to assess the microleakage of one high-viscosity conventional glass ionomer cement (GIC and a bulk-fill composite resin, in comparison to a resin-modified GIC in Class II restorations in primary molars. Materials and Method: Standardized Class II slot cavity preparations were prepared in exfoliating primary molars. Teeth were restored using one of the three materials tested (n = 10: SonicFill bulk-fill composite resin (SF, EQUIA Fil conventional reinforced GIC (EQF, and Vitremer resin-reinforced GIC (VT. The restorations were then subjected to thermocycling procedure (×2000 5°C–55°C 10 s/min and soaked in 1% neutralized fuchsin solution (pH: 7.4 for 24 h at 37°C. Teeth were sectioned longitudinally in a mesiodistal direction under continuous cooling into three slabs of 1 mm thickness and studied under a stereomicroscope for dye penetration. Statistical Analysis: Data were evaluated by one-way analysis of variance and the Tukey's multiple comparison test employing 95% (α = 0.05. Results: EQF and SF showed significantly lower microleakage scores and percentage of dye penetration (%RL when compared to VT resin-reinforced GIC (P < 0.001. Conclusion: SF and EQF produced the minimum microleakage when compared to VT in Class II restorations on primary molars. Fewer application procedures and reduction in treatment time in SF and EQF systems proved advantageous in pediatric dentistry.

  17. Calculation of the shrinkage-induced residual stress in a viscoelastic dental restorative material

    Science.gov (United States)

    Grassia, Luigi; D'Amore, Alberto

    2013-02-01

    A procedure able to describe the curing process of a particulate composite material used in a dental restoration is developed in the ANSYS environment. The material under concern is a multifunctional methacrylate-based composite for dental restoration, activated by visible light. The model accounts for the dependence of the viscoelastic functions on temperature and degree of cure. Three geometries have been considered in the analysis that are representative of three different classes of dental restoration and mainly differ by the C (constrained)-factor, (i.e. the bounded to unbounded surface ratio). It was found that the temperature could give a necrosis in the vicinity of the tooth nerve and that the average stress at the interface between the composite and the tooth scales exponentially with the C-factor. The residual stress at the dental restoration interface is also compared with the uniaxial tensile strength of twelve commercially available composite materials: it clearly appears that the level of residual stress may overcome the strength of the composite, especially at high C-factors.

  18. Impact of intracoronal dentin treatment prior to bleaching on bond strength of restorative materials.

    Science.gov (United States)

    Zanconato-Carvalho, Erica Moreno; Bruniera, João Felipe; Faria, Natália Spadini de; Colucci, Vivian; Messias, Danielle Cristine

    2014-01-01

    Surface treatment of dentin before the bleaching procedure may affect its permeability and influence the bond strength of restorative materials. This study evaluated the influence of surface treatment before the bleaching on shear bond strength (SBT) of restorative materials to intracoronal dentin. Dentin slabs were subjected to surface treatment: no bleaching (control - CON), no surface treatment + bleaching (HP), 37% phosphoric acid + bleaching (PA) and Er:YAG laser + bleaching (L). After the bleaching procedure, specimens (n=10) were restored with: microhybrid composite resin (MH), flowable composite resin (F), and resin-modified glass-ionomer cement (RMGIC). The shear test was carried out. ANOVA and Tukey's test (α=0.05) showed significant difference for surface treatment and restorative materials (p0.05). STB for MH and F were higher than RMGIC (p0.05). The surface treatments with phosphoric acid and Er:YAG laser before the bleaching procedure provided shear bond strength at the same level of unbleached dentin and the composite resins presented superior bond strength to the intracoronal dentin.

  19. Insights into functional tea infused-chitosan hydrogels as potential bio-active restorative materials

    Directory of Open Access Journals (Sweden)

    Tamara V Perchyonok

    2014-01-01

    Full Text Available Introduction: We described novel chitosan hydrogels (chitosan-H containing tea infusions (green, red and black as functional additive prototypes with special focus on the design and functionality of dual action composite restorative materials. Their intended uses include remineralizing bases/liners, therapeutically active restorative materials and/or functional additives as well as functional prototype of the drug delivery system. Materials and Methods: The above mentioned hydrogels were prepared by dispersion of the corresponding component in glycerol and acetic acid with the addition of chitosan gelling agent. The surface morphology scanning electron microscope (SEM, release behavior (physiological pH as well as acidic conditions, stability of the hydrogels as well as antioxidant capacity of the tea infused hydrogels was evaluated. Results: It was found that all the anti-oxidant chitosan-H hydrogels treated dentine gave significantly (P < 0.05; Non-parametric ANOVA test higher shear bond strength values than dentine treated or not treated with phosphoric acid. Overall, there was a small relapse in the shear bond strength after 6 months. The SEM is employed to observe the surface of the newly made functional restorative materials. The anti-oxidant capacity of various black, red and green tea infusions was investigated and demonstrated increased antioxidant stability of the newly prepared material stability. Conclusion: We have developed and evaluated several functional chitosan hydrogels with several targets as therapeutic restorative materials, the added benefits of their unique functionality involve increased dentin adhesive bond strengths (after 24 h and after 6 month, concept of using functional materials as carriers for pro-drugs as well as display certain degree of defense mechanism for a free radical damage.

  20. A 7-year randomized prospective study of a one-step self-etching adhesive in non-carious cervical lesions. The effect of curing modes and restorative material

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2012-01-01

    Objective: The aim of this study was to evaluate the clinical retention of a one-step self-etching adhesive system (Xeno III) in Class V non-carious cervical lesions and the effect of restorative material and curing techniques on longevity of the restorations. Material and methods: A total of 139...... Class V restorations were placed with the self-etching primer Xeno III and a resin composite (Tetric Ceram) or a poly-acid modified resin composite (Dyract AP) in non-carious cervical lesions without intentional enamel involvement. The materials were cured with a conventional continuous light, a soft...... be evaluated. No post-operative sensitivity was reported by the participants. Overall relative cumulative loss rate frequencies for the adhesive system at 6, 18 and 7 years, independent of curing technique and restorative material, were 0.8%, 6.9% and 23.0%, respectively. The self-etching adhesive fulfilled...

  1. Priorities for future innovation, research, and advocacy in dental restorative materials.

    Science.gov (United States)

    Watson, T; Fox, C H; Rekow, E D

    2013-11-01

    Innovations in materials science, both within and outside of dentistry, open opportunities for the development of exciting direct restorative materials. From rich dialog among experts from dental and non-dental academic institutions and industry, as well as those from policy, research funding, and professional organizations, we learned that capitalizing on these opportunities is multifactorial and far from straightforward. Beginning from the point when a restoration is needed, what materials, delivery systems, and skills are needed to best serve the most people throughout the world's widely varied economic and infrastructure systems? New research is a critical element in progress. Effective advocacy can influence funding and drives change in practice and policy. Here we articulate both research and advocacy priorities, with the intention of focusing the energy and expertise of our best scientists on making a difference, bringing new innovations to improve oral health.

  2. Translucency of human teeth and dental restorative materials and its clinical relevance

    Science.gov (United States)

    Lee, Yong-Keun

    2015-04-01

    The purpose was to review the translucency of human teeth and related dental materials that should be considered for the development of esthetic restorative materials. Translucency is the relative amount of light transmission or diffuse reflection from a substrate surface through a turbid medium. Translucency influences the masking ability, color blending effect, and the degree of light curing through these materials. Regarding the translucency indices, transmission coefficient, translucency parameter, and contrast ratio have been used, and correlations among these indices were confirmed. Translucency of human enamel and dentine increases in direct proportion to the wavelength of incident light in the visible light range. As for the translucency changes by aging, limited differences were reported in human dentine, while those for enamel proved to increase. There have been studies for the adjustment of translucency in dental esthetic restorative materials; the size and amount of filler and the kind of resin matrix were modified in resin composites, and the kind of ingredient and the degree of crystallization were modified in ceramics. Based on the translucency properties of human enamel and dentine, those of replacing restorative materials should be optimized for successful esthetic rehabilitation. Biomimetic simulation of the natural tooth microstructure might be a promising method.

  3. A comparative evaluation of four restorative materials to support undermined occlusal enamel of permanent teeth.

    Science.gov (United States)

    Prabhakar, A R; Thejokrishna, P; Kurthukoti, A J

    2006-09-01

    The purpose of this study was to test the support to undermined occlusal enamel provided by posterior restorative composite (FiltekTM P60, 3M Dental products USA), polyacid modified resin composite (F2000 compomer, 3M Dental products, USA.), radiopaque silver alloy-glass ionomer cement (Miracle Mix. GC Corp, Tokyo, Japan) and Glass Ionomer cement (Fuji IX GP). To test each material, 20 human permanent mandibular third molars were selected. The lingual cusps were removed and the dentin supporting the facial cusps was cut away, leaving a shell of enamel. Each group of prepared teeth was restored using the materials according to the manufacturer's instructions. All the specimens were thermocycled (250 cycles, 6 degrees C- 60 degrees C, dwell time 30 seconds) and then mounted on an acrylic base. Specimens were loaded evenly across the cusp tips at a crosshead speed of 5 mm /minute in Hounsfield universal testing machine until fracture occurred. Data obtained was analyzed using analysis of variance and Studentized- Newman- Keul's range test. No significant differences were detected in the support provided by P-60, F 2000, Miracle Mix or Fuji IX GP groups. The support provided to undermined occlusal enamel by these materials was intermediate between no support and that provided by sound dentin. Without further development in dental material technology and evidence of its efficacy, restorative materials should not be relied upon to support undermined occlusal enamel to a level comparable to that provided by sound dentin.

  4. A comparative evaluation of four restorative materials to support undermined occlusal enamel of permanent teeth

    Directory of Open Access Journals (Sweden)

    Prabhakar A

    2006-09-01

    Full Text Available The purpose of this study was to test the support to undermined occlusal enamel provided by posterior restorative composite (FiltekTM P60, 3M Dental products USA, polyacid modified resin composite (F2000 compomer, 3M Dental products, USA., radiopaque silver alloy-glass ionomer cement (Miracle Mix. GC Corp, Tokyo, Japan and Glass Ionomer cement (Fuji IX GP. To test each material, 20 human permanent mandibular third molars were selected. The lingual cusps were removed and the dentin supporting the facial cusps was cut away, leaving a shell of enamel. Each group of prepared teeth was restored using the materials according to the manufacturer′s instructions. All the specimens were thermocycled (250 cycles, 6°C- 60°C, dwell time 30 seconds and then mounted on an acrylic base. Specimens were loaded evenly across the cusp tips at a crosshead speed of 5 mm /minute in Hounsfield universal testing machine until fracture occurred. Data obtained was analyzed using analysis of variance and Studentized- Newman- Keul′s range test. No significant differences were detected in the support provided by P-60, F 2000, Miracle Mix or Fuji IX GP groups. The support provided to undermined occlusal enamel by these materials was intermediate between no support and that provided by sound dentin. Without further development in dental material technology and evidence of its efficacy, restorative materials should not be relied upon to support undermined occlusal enamel to a level comparable to that provided by sound dentin.

  5. Coronal microleakage with five different temporary restorative materials following walking bleach technique: An ex-vivo study

    Directory of Open Access Journals (Sweden)

    G. P. V Srikumar

    2012-01-01

    Full Text Available Context: Walking bleach technique uses 30% hydrogen peroxide and sodium perborate, and this paste mixture causes loosening of the coronal temporary restorative materials and thus decreasing its clinical effectiveness and causing irritation to the patients oral tissues. In the present study, sealing ability of hygroscopic coronal temporary restorative materials were compared with the other commonly used temporary restorative materials. Aim: To evaluate the effects of walking bleach material on the marginal sealing ability and coronal microleakage of the hydrophilic temporary restorative materials with that of the other commonly used temporary restorative materials in endodontic practice. Materials and Methods: Seventy-five extracted human maxillary central incisor teeth were prepared chemo-mechanically and obturated with gutta-percha in lateral condensation technique. Surface of each tooth was double coated with cyanoacrylate glue. All the teeth were randomly divided in to five groups. Out of 15 teeth in each group, 10 teeth served as experimental specimens, in which bleaching agent was placed in the pulp chamber and 5 teeth served as control, in which no bleaching agent was placed. The access cavities were restored with temporary restorative materials being tested per each group respectively. The specimens were then immersed in 1% India ink dye and subjected to thermo cycling for 7 days. All the teeth were longitudinally sectioned and observed with stereomicroscope and were graded according to the depth of linear dye penetration. Statistical Analysis Used: Mann-Whitney U test and Kruskal-Wallis test. Results: Hydrophilic temporary restorative materials Cavit G and Coltosol F have shown minimal coronal dye leakage with better sealing ability when exposed to walking bleach paste mixture in the dye penetration tests compared to other commonly used temporary restorative materials. Conclusion: Marginal sealing ability of Cavit G and Coltosol F were

  6. Effect of dental restorative materials on total antioxidant capacity and calcium concentration of unstimulated saliva

    Science.gov (United States)

    Moghadam, Mona-Momeni; Garcia-Godoy, Franklin; Asatourian, Armen; Aminsobhani, Mohsen; Scarbecz, Mark; Sheibani, Nader

    2017-01-01

    Background To evaluate the effect of dental amalgam and composite restorations on total antioxidant capacity (TAC) and calcium (Ca) ion concentration of unstimulated saliva. Material and Methods Forty-eight children aged 6-10 years selected and divided into three groups of sixteen (8 males, 8 females). In group A and B, samples consisted of two class II dental composite or amalgam restorations, while in group C samples were caries-free (control group). Unstimulated saliva from all samples was collected and TAC was measured by spectrophotometry using an adaptation of 2, 2’-azino-di-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) assay. The Ca ion level was estimated by an auto- analyzer. Data were analyzed with one- and two-way ANOVA test, at a p<.05 level of significance. Results Composite samples showed significantly higher TAC and lower Ca ion levels compared to amalgam and caries-free samples (p<.05). The TAC values showed only significant difference between groups (p<.05), while the Ca ion results showed significant differences within and between groups (p<.05). Conclusions Dental composite restorations increased TAC and decreased Ca ion levels more than amalgam restorations in saliva. Gender is an effective factor in changes induced in oral cavity as females showed more emphatic reaction to dental filling materials than males. Statement of Clinical Relevance Patients who have dental restorations, especially dental composites, should pay more attention to their dental hygiene, because dental restorations can increase oxidative stress and decrease Ca ion level in saliva, which might jeopardize remineralization process of tooth structures after demineralization. Key words:Amalgam, caries, composite, saliva, total antioxidant capacity. PMID:28149467

  7. Evaluation of the Flexural Strength of Interim Restorative Materials in Fixed Prosthodontics.

    Science.gov (United States)

    Mehrpour, Hanieh; Farjood, Ehsan; Giti, Rashin; Barfi Ghasrdashti, Alireza; Heidari, Hossein

    2016-09-01

    Mechanical properties of interim restorations are considered as important factors specially when selecting materials for long-term application or for patients with para-functional habits. Flexural strength is one of the most important components of these restorations. The purpose of this study was to compare the flexural strength of five interim restorative materials. Fifty identical samples sized 25×2×2-mm were made from five interim materials (TempSpan; Protemp 4, Unifast III, Trim, and Revotek LC) according to ADA specification #27. The specimens were stored in artificial saliva for 2 weeks and then thermocycled for 2500 cycles (5-55˚C). A standard three-point bending test was conducted on the specimens with a universal testing machine at a crosshead speed of 0.75mm/min. Data were analyzed by using one-way ANOVA and Tamhane's post-hoc tests to measure the flexural strength of temporary materials. One of the bis-acryl resins (TempSpan) showed the highest, and the light polymerized resin (Revotek LC) showed the lowest flexural strength. The mean values of flexural strength (MPa) for the examined materials were as follow: TempSpan=120.00, Protemp 4=113.00, Unifast III=64.20, Trim= 63.73 and Revotek LC=47.16. There were significant differences between all materials except Trim and Unifast III which did not show any statistical significant difference. Bis-acryl resins were statistically superior to traditional methacrylate and light-cured resins. Therefore, application of bis-acryl resins should be deliberated in patients with heavy occlusion and in cases that need long-term use of interim restorations.

  8. Effect of using different base materials on microleakage of class V restorations

    OpenAIRE

    Yıkılgan, İhsan; Akgül, Sinem; Kuşoğlu, Aslı; Bala, Oya; Ömürlü, Hüma; Türköz, Mehmet Emin

    2017-01-01

    Objective: The aim of this in vitro study was to evaluate and compare the effect of using different base materials on microleakage of class V restorations.Materials and Method: In this study 60 extracted non-cavitated human molar teeth were used. Class V cavities were prepared on the buccal surfaces in 4 mm mesio-distal, 3 mm gingivo-occlusal width and 3 mm depth. The teeth were randomly divided into five groups: Group 1: resin-modified calcium silicate material (TheraCal LC), Group 2: self-a...

  9. Effect of using different base materials on microleakage of class V restorations

    OpenAIRE

    İhsan Yıkılgan; Sinem Akgül; Aslı Kuşoğlu; Oya Bala; Hüma Ömürlü; Mehmet Emin Türköz

    2017-01-01

    Objective: The aim of this in vitro study was to evaluate and compare the effect of using different base materials on microleakage of class V restorations. Materials and Method: In this study 60 extracted non-cavitated human molar teeth were used. Class V cavities were prepared on the buccal surfaces in 4 mm mesio-distal, 3 mm gingivo-occlusal width and 3 mm depth. The teeth were randomly divided into five groups: Group 1: resin-modified calcium silicate material (TheraCal LC), Group 2: s...

  10. Effects of pulp capping materials on fracture resistance of Class II composite restorations

    OpenAIRE

    2015-01-01

    Objective: The aim of this study was to investigate the effect of cavity design and the type of pulp capping materials on the fracture resistance of Class II composite restorations. Materials and Methods: Sixty freshly extracted, sound molar teeth were selected for the study. A dovetail cavity on the mesio-occlusal and a slot cavity on disto-occlusal surfaces of each tooth were prepared, and the teeth were divided 4 groups which one of them as a control group. The pulp capping materials (Ther...

  11. Recommendations for conducting controlled clinical studies of dental restorative materials. Science Committee Project 2/98--FDI World Dental Federation study design (Part I) and criteria for evaluation (Part II) of direct and indirect restorations including onlays and partial crowns.

    Science.gov (United States)

    Hickel, Reinhard; Roulet, Jean-François; Bayne, Stephen; Heintze, Siegward D; Mjör, Ivar A; Peters, Mathilde; Rousson, Valentin; Randall, Ros; Schmalz, Gottfried; Tyas, Martin; Vanherle, Guido

    2007-01-01

    About 35 years ago, Ryge provided a practical approach to the evaluation of the clinical performance of restorative materials. This systematic approach was soon universally accepted. While that methodology has served us well, a large number of scientific methodologies and more detailed questions have arisen that require more rigor. Current restorative materials have vastly improved clinical performance, and any changes over time are not easily detected by the limited sensitivity of the Ryge criteria in short-term clinical investigations. However, the clinical evaluation of restorations not only involves the restorative material per se but also different operative techniques. For instance, a composite resin may show good longevity data when applied in conventional cavities but not in modified operative approaches. Insensitivity, combined with the continually evolving and nonstandard investigator modifications of the categories, scales, and reporting methods, has created a body of literature that is extremely difficult to interpret meaningfully. In many cases, the insensitivity of the original Ryge methods leads to misinterpretation as good clinical performance. While there are many good features of the original system, it is now time to move on to a more contemporary one. The current review approaches this challenge in two ways: (1) a proposal for a modern clinical testing protocol for controlled clinical trials, and (2) an in-depth discussion of relevant clinical evaluation parameters, providing 84 references that are primarily related to issues or problems for clinical research trials. Together, these two parts offer a standard for the clinical testing of restorative materials/procedures and provide significant guidance for research teams in the design and conduct of contemporary clinical trials. Part 1 of the review considers the recruitment of subjects, restorations per subject, clinical events, validity versus bias, legal and regulatory aspects, rationales for

  12. Cytogenetic genotoxic investigation in peripheral blood lymphocytes of subjects with dental composite restorative filling materials.

    Science.gov (United States)

    Pettini, F; Savino, M; Corsalini, M; Cantore, S; Ballini, A

    2015-01-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. The objective of this study was to evaluate the genotoxicity of a common dental composite material (Enamel Plus-HFO), in subjects with average 13 filled teeth with the same material, compared to a control group (subjects having neither amalgam nor composite resin fillings). Genotoxicity assessment of composite materials was carried out in vitro in human peripheral blood leukocytes using sister-chromatid exchange (SCE) and chromosomal aberrations (CA) cytogenetic tests. The results of correlation and multiple regression analyses confirmed the absence of a relationship between SCE/cell, high frequency of SCE(HFC) or CA frequencies and exposure to dental composite materials. These results indicate that composite resins used for dental restorations differ extensively in vivo in their cytotoxic and genotoxic potential and in their ability to affect chromosomal integrity, cell-cycle progression, DNA replication and repair.

  13. Effectiveness of the temporary sealing of three restorative materials to the 50% silver nitrate solution

    Directory of Open Access Journals (Sweden)

    Elias Pandonor Motcy de OLIVEIRA

    2010-03-01

    Full Text Available Introduction and objective: The aim of this study was to analyze threetemporary restorative materials – Coltosol®, Cavit® W and Cimpat®–, concerning their sealing capacity to the 50% silver nitrate solution.Material and methods: 30 samples were divided into 3 experimental groups. Inside of each sample there was an antibiogram disc with 5 mm of diameter and 1 mm of depth, with 4 mm of one of the three sealing materials on it. After restorations, the samples were inserted into recipients with 50% silver nitrate solution, which were taken to the heater at 37ºC, where they remained for 7 days. Following this period and with the restorative materials removed, antibiogram disc analyses were performed, which were scored according to the leakage. Results and conclusion: Data obtained were submitted to the Kruskal-Wallis non-parametric statistical test, with a level of significance of 5%. Results showed that Cimpat® had the greatest levels of leakage, while Coltosol® and Cavit® W did not differ between themselves (p > 0.05.

  14. Shear Bond Strength of Repair Systems to New CAD/CAM Restorative Materials.

    Science.gov (United States)

    Üstün, Özlem; Büyükhatipoğlu, Işıl Keçik; Seçilmiş, Aslı

    2016-11-23

    To evaluate the bond strength of repair systems (Ceramic Repair, Clearfil Repair) to computer-aided design/computer-assisted machining (CAD/CAM) restorative materials (IPS e.max CAD, Vita Suprinity, Vita Enamic, Lava Ultimate). Thermally aged CAD/CAM restorative material specimens (5000 cycles between 5°C and 55°C) were randomly divided into two groups according to the repair system: Ceramic Repair (37% phosphoric acid + Monobond-S + Heliobond + Tetric N Ceram) or Clearfil Repair (40% phosphoric acid + mixture of Clearfil Porcelain Bond Activator and Clearfil SE Bond Primer + Clearfil SE Bond + Filtek Z250). The resin composite was light-cured on conditioned specimens. All specimens were stored in distilled water at 37°C for 24 hours and then additionally aged for 5000 thermal cycles. The shear bond strength test was performed using a universal testing machine (0.5 mm/min). Two-way ANOVA was used to detect significance differences according to the CAD/CAM material and composite repair system factors. Subgroup analyses were conducted using the least significant difference post-hoc test. The results of two-way ANOVA indicated that bond strength values varied according to the restorative materials (p CAD/CAM restorative materials (p > 0.05), except in the Vita Suprinity group (p < 0.05). Moreover, no differences were observed between the repair systems. Both the Clearfil and Ceramic repair systems used in the study allow for successful repairs. © 2016 by the American College of Prosthodontists.

  15. Effect of using different base materials on microleakage of class V restorations

    Directory of Open Access Journals (Sweden)

    İhsan Yıkılgan

    2017-01-01

    Full Text Available Objective: The aim of this in vitro study was to evaluate and compare the effect of using different base materials on microleakage of class V restorations. Materials and Method: In this study 60 extracted non-cavitated human molar teeth were used. Class V cavities were prepared on the buccal surfaces in 4 mm mesio-distal, 3 mm gingivo-occlusal width and 3 mm depth. The teeth were randomly divided into five groups: Group 1: resin-modified calcium silicate material (TheraCal LC, Group 2: self-adhesive flowable composite resin (Fusio Liquid Dentin, Group 3: flowable composite resin liner (Tetric N Flow, Group 4: resin-modified glass ionomer liner (Ketac N100, Group 5: control group. Materials in the experimental groups were placed in 1 mm thickness as liner. Then, a nanohybrid composite resin (Grandio was placed and restorations were completed. In the control group, no base material was applied. After finishing and polishing procedures, thermocycling was performed 5000 times between 5-55 °C. Microleakage of restorations was evaluated by using dye penetration method (basic fuchsin. Results were analyzed by Kruskal Wallis with Bonferroni correction and Mann-Whitney U tests. Results: Regarding occlusal microleakage, no statistically significant difference was found between the groups (p=0.267; however significant difference was found between the gingival microleakage scores (p=0.004. Compared to Fusio Liquid Dentin and control groups, significantly less dye penetration was found in Theracal LC, Tetric N-Flow and Ketac N-100 groups (p0.01. Conclusion: Within the limitation of this study, the conclusion was that the use of a liner (except Fusio Liquid Dentin under composite resin in a class V cavity reduced the microleakage of the restoration.

  16. Influence of intermediary filling material on microleakage of intracoronally bleached and restored teeth

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2009-01-01

    Full Text Available Background: Failure of composite restorations in terms of microleakage after intracoronal bleaching has been reported. The purpose of this study was to assess in vitro effect of sodium ascorbate and calcium hydroxide as intermediary filling materials to repair the microleakage associated with adhe-sive restoration following intracoronal bleaching. Methods: Sixty endodontically-treated incisors with access cavities extended to the cementoenamel junction in gingival margin were randomly divided into five equal groups. In group 1, cavities were restored by applying Single Bond and Z100 composite resin. In groups 2-5, 35% hydrogen peroxide gel was placed into the pulp chamber and sealed for 5 days. In group 2, teeth were then restored as in group 1. In groups 3 and 4, 10% sodium ascorbate gel and calcium hydroxide paste were applied in the pulp chamber for 40 hours, removed, rinsed and then, restored. In group 5, the cavities were incu-bated for 7 days and then, restored. Samples were thermocycled, immersed in basic fuschin, and sec-tioned. Dye penetration was scored using a stereomicroscope. Data were analyzed using Kruskal- Wallis and Mann-Whitney U tests (α = 0.05. Results: There was no significant difference in enamel margins (P = 0.163. In dentinal margins (P = 0.003, groups 1, 3 and 5 exhibited similar leakage patterns, each one of groups 1, 3 and 5 had sig-nificant differences with each one of groups 2 and 4. Conclusion: Intracoronal bleaching using 35% H2O2 gel increases the microleakage in dentinal margins. Application of the antioxidant agent or a seven-day delay following bleaching may improve the marginal integrity. Applying calcium hydroxide might jeopardize dentinal sealing.

  17. Comparative evaluation of microleakage between bulk esthetic materials versus resin-modified glass ionomer to restore Class II cavities in primary molars.

    Science.gov (United States)

    Gopinath, Vellore Kannan

    2017-01-01

    The aim of the study was to assess the microleakage of one high-viscosity conventional glass ionomer cement (GIC) and a bulk-fill composite resin, in comparison to a resin-modified GIC in Class II restorations in primary molars. Standardized Class II slot cavity preparations were prepared in exfoliating primary molars. Teeth were restored using one of the three materials tested (n = 10): SonicFill bulk-fill composite resin (SF), EQUIA Fil conventional reinforced GIC (EQF), and Vitremer resin-reinforced GIC (VT). The restorations were then subjected to thermocycling procedure (×2000 5°C-55°C 10 s/min) and soaked in 1% neutralized fuchsin solution (pH: 7.4) for 24 h at 37°C. Teeth were sectioned longitudinally in a mesiodistal direction under continuous cooling into three slabs of 1 mm thickness and studied under a stereomicroscope for dye penetration. Data were evaluated by one-way analysis of variance and the Tukey's multiple comparison test employing 95% (α = 0.05). EQF and SF showed significantly lower microleakage scores and percentage of dye penetration (%RL) when compared to VT resin-reinforced GIC (P < 0.001). SF and EQF produced the minimum microleakage when compared to VT in Class II restorations on primary molars. Fewer application procedures and reduction in treatment time in SF and EQF systems proved advantageous in pediatric dentistry.

  18. Impression materials and techniques used for cast restorations in eight states.

    Science.gov (United States)

    Shillingburg, H T; Hatch, R A; Keenan, M P; Hemphill, M W

    1980-05-01

    In a survey of dentists practicing in eight states, it was found that polysulfide is used by 35.8% of them for cast restorations. Polyether and hydrocolloid are the second most used materials; silicone putty/reline and double mix standard silicone follow. Epinephrine cord was chosen for gingival retraction by 73.3% of the respondents. Nonepinephrine cord is used by 23.5% of the dentists who responded.

  19. Chemical or microbiological models of secondary caries development around different dental restorative materials.

    Science.gov (United States)

    Lobo, Maristela M; Gonçalves, Reginaldo B; Ambrosano, Gláucia Maria B; Pimenta, Luiz André F

    2005-08-01

    This study evaluated artificial secondary caries around restorative materials, induced by means of chemical or microbiological models. The following materials were used randomly to restore 130 dental blocks: (1) zinc-oxide eugenol-free temporary filling: Coltosol (Coltène/Whaledent Inc.; n = 30), (2) silver amalgam: Permite C (SDI Limited, n = 20), (3) composite resin: Filtek Z250 (3M ESPE; n = 20), (4) glass-ionomer cement: Fuji II (GC America Inc.; n = 20), (5) resin-modified glass ionomer: Vitremer (3M ESPE; n = 20), and (6) polyacid modified resin: Dyract AP (Dentsply; n = 20). Ten specimens of Group 1 were kept in humidity, and had no carious formation (NC). Ten specimens of each group were submitted to pH cycling (CG, n = 60), and the others were immersed in a medium containing Streptococcus mutans and sucrose (BG, n = 60). Mineral content was determined by microhardness assessment, and lesion depth was measured in polarized light photomicrographs. In the chemical model (CG), mineral content values in the vicinities of restoration were high for Groups 5 (75.7 +/- 11.9), 4 (70.8 +/- 14.2), and NC (95.4 +/- 3.8); intermediate for Groups 1 (55.8 +/- 18.5), 6 (45.6 +/- 11.0), and 2 (44.3 +/- 11.2); and reduced for Group 3 (34.7 +/- 9.7). In the microbiological model (BG), results were similar to CG, although there was less demineralization. The highest lesion depths were found for Groups 3 (182.3 +/- 33.2) in CG and 6 (126.5 +/- 42.8) in BG, when compared to Group 5 (114.6 +/- 26.0 and 56.2 +/- 33.2, respectively). In both models of caries induction, ionomeric materials showed a superior cariostatic effect when compared to the other restorative materials.

  20. A comparative evaluation of four restorative materials to support undermined occlusal enamel of permanent teeth

    OpenAIRE

    Prabhakar A; Thejokrishna P; Kurthukoti A

    2006-01-01

    The purpose of this study was to test the support to undermined occlusal enamel provided by posterior restorative composite (FiltekTM P60, 3M Dental products USA), polyacid modified resin composite (F2000 compomer, 3M Dental products, USA.), radiopaque silver alloy-glass ionomer cement (Miracle Mix. GC Corp, Tokyo, Japan) and Glass Ionomer cement (Fuji IX GP). To test each material, 20 human permanent mandibular third molars were selected. The lingual cusps were removed and the dentin support...

  1. Investigation into the Depth of Cure of Resin-Modified Glass-Ionomer Restorative Materials

    Science.gov (United States)

    2006-08-01

    cured glass ionomer and a chemically cured glass ionomer for use as an orthodontic bonding agent. American Journal of Orthodontics and Dentofacial...Sciences Jeffrey M. UK, kb.’ Kraig S. Vanwalle, DDS, MS Approved on 00 ACKNOWLEDGEMENTS This thesis is the result of clinical questions that I have...pondered over years of clinically using resin-modified glass-ionomer restorative materials. Unfortunately, as with all research, as this thesis comes to a

  2. Multi-material laser densification (MMLD) of dental restorations: Process optimization and properties evaluation

    Science.gov (United States)

    Li, Xiaoxuan

    This Ph.D. thesis proposes to investigate the feasibility of laser-assisted dental restoration and to develop a fundamental understanding of the interaction between laser beam and dental materials. Traditional dental restorations are produced by the porcelain-fused-to-metal (PFM) process, in which a dental restoration is cast from a metallic alloy and then coated with dental porcelains by multiple furnace-firing processes. PFM method is labor-intensive and hence very expensive. In order to fabricate dental restoration units faster and more cost-effectively, the Solid Freeform Fabrication (SFF) technique has been employed in this study. In particular, a Multi-Material Laser Densification (MMLD) process has been investigated for its potential to fabricate artificial teeth automatically from 3-D computer dental tooth files. Based on the principle of SFF, the MMLD process utilizes a micro-extruder system to deliver commercial dental alloy and porcelain slurry in a computer-controlled pattern line by line and layer by layer. Instead of firing the artificial tooth/teeth in a furnace, the extruded dental materials are laser scanned to convert the loose powder to a fully dense body. Different laser densification parameters including the densification temperature, laser output power, laser beam size, line dimension, ratio of the beam size to line width, beam scanning rate, processing atmosphere and pressure, dental powder state (powder bed or slurry), powder particle size, etc. have been used to evaluate their effects on the microstructures and properties of the laser densified dental body, and hence to optimize MMLD conditions. Furthermore, laser-scanning induced phase transformations in dental porcelains have been studied because the transformations have great impact on coefficient of thermal expansion (CTE) of dental porcelains, which should match that of dental alloy substrate. Since a single dental material line delivered by the MMLD system functions as a "construction

  3. Microleakage of conventional, resin-modified, and nano-ionomer glass ionomer cement as primary teeth filling material

    Directory of Open Access Journals (Sweden)

    Dita Madyarani

    2014-12-01

    Full Text Available Background: Glass ionomer cements are one of many dental materials that widely used in pediatric dentistry due to their advantage of fluoride release and chemical bond to tooth structure. Adherence of the filling material to the cavity walls is one of the most important characteristic that need to be examined its effect on microleakage. Purpose: This study was conducted to examine the microleakage of nano-ionomer glass ionomer cement compared with the conventional and resin-modified glass ionomer cements. Methods: Standard class V cavities sized 3 mm x 2 mm x 2 mm were made on a total of 21 extracted maxillary primary canine teeth and restored with the conventional, resin-modified, dan nano-ionomer glass ionomer cements. All the teeth were immersed in a 2% methylene blue dye for 4 hours. The depth of dye penetration was assessed using digital microscope after sectioning the teeth labio-palatally. The results were statistically analyzed using Kruskal-Wallis test. Results: All type of glass ionomer material showed microleakage. Conventional glass ionomer cement demonstrated the least microleakage with mean score 1.29. the resin-modified glass ionomer cements (mean score 1.57 and nano-ionomer glass ionomer cement (mean score 2.57. Conclusion: The conventional glassionomer, resin modified glassionomer, and nano-ionomer glassionomer showed micro leakage as filling material in primary teeth cavity. The micro leakage among three types was not significant difference. All three material were comparable in performance and can be used for filling material but still needs a coating material to fill the microleakage.Latar belakang: Semen ionomer kaca adalah salah satu dari banyak bahan gigi yang banyak digunakan dalam praktek kedokteran gigi anak karena bahan tersebut merilis fluoride dan berikatan kimia dengan struktur gigi. Perlekatan bahan tumpatan pada dinding kavitas adalah salah satu karakteristik paling penting yang perlu diteliti efeknya terhadap

  4. Quantification of Staphylococcus aureus adhesion forces on various dental restorative materials using atomic force microscopy

    Science.gov (United States)

    Merghni, Abderrahmen; Kammoun, Dorra; Hentati, Hajer; Janel, Sébastien; Popoff, Michka; Lafont, Frank; Aouni, Mahjoub; Mastouri, Maha

    2016-08-01

    In the oral cavity dental restorative biomaterials can act as a reservoir for infection with opportunistic Staphylococcus aureus pathogen, which can lead to the occurrence of secondary caries and treatment failures. Our aim was to evaluate the adhesion forces by S. aureus on four dental restorative biomaterials and to correlate this finding to differences in specific surface characteristics. Additionally, the influence of salivary conditioning films in exerted adhesion forces was investigated. The substrate hydrophobicity was measured by goniometer and the surface free energy was calculated using the equilibrium advancing contact angle values of water, formamide, and diiodomethane on the tested surfaces. The surface roughness was determined using atomic force microscope (AFM). Additionally, cell force spectroscopy was achieved to quantify the forces that drive cell-substrate interactions. S. aureus bacterium exerted a considerable adhesion forces on various dental restorative materials, which decreased in the presence of saliva conditioning film. The influence of the surface roughness and free energy in initial adhesion appears to be more important than the effect of hydrophobicity, either in presence or absence of saliva coating. Hence, control of surface properties of dental restorative biomaterials is of crucial importance in preventing the attachment and subsequent the biofilm formation.

  5. Restoring proximal caries lesions conservatively with tunnel restorations

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    Chu CH

    2013-07-01

    Full Text Available Chun-Hung Chu1, May L Mei,1 Chloe Cheung,1 Romesh P Nalliah2 1Faculty of Dentistry, The University of Hong Kong, Hong Kong, People's Republic of China; 2Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA, USA Abstract: The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations. Keywords: operative, practice, tunnel preparation, composite, amalgam, glass ionomer

  6. Molecular Toxicology of Substances Released from Resin–Based Dental Restorative Materials

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    Athina Bakopoulou

    2009-09-01

    Full Text Available Resin-based dental restorative materials are extensively used today in dentistry. However, significant concerns still remain regarding their biocompatibility. For this reason, significant scientific effort has been focused on the determination of the molecular toxicology of substances released by these biomaterials, using several tools for risk assessment, including exposure assessment, hazard identification and dose-response analysis. These studies have shown that substances released by these materials can cause significant cytotoxic and genotoxic effects, leading to irreversible disturbance of basic cellular functions. The aim of this article is to review current knowledge related to dental composites’ molecular toxicology and to give implications for possible improvements concerning their biocompatibility.

  7. Molecular Toxicology of Substances Released from Resin–Based Dental Restorative Materials

    Science.gov (United States)

    Bakopoulou, Athina; Papadopoulos, Triantafillos; Garefis, Pavlos

    2009-01-01

    Resin-based dental restorative materials are extensively used today in dentistry. However, significant concerns still remain regarding their biocompatibility. For this reason, significant scientific effort has been focused on the determination of the molecular toxicology of substances released by these biomaterials, using several tools for risk assessment, including exposure assessment, hazard identification and dose-response analysis. These studies have shown that substances released by these materials can cause significant cytotoxic and genotoxic effects, leading to irreversible disturbance of basic cellular functions. The aim of this article is to review current knowledge related to dental composites’ molecular toxicology and to give implications for possible improvements concerning their biocompatibility. PMID:19865523

  8. Dynamic Analysis of Heavy Vehicle Medium Duty Drive Shaft Using Conventional and Composite Material

    Science.gov (United States)

    Kumar, Ashwani; Jain, Rajat; Patil, Pravin P.

    2016-09-01

    The main highlight of this study is structural and modal analysis of single piece drive shaft for selection of material. Drive shaft is used for torque carrying from vehicle transmission to rear wheel differential system. Heavy vehicle medium duty transmission drive shaft was selected as research object. Conventional materials (Steel SM45 C, Stainless Steel) and composite materials (HS carbon epoxy, E Glass Polyester Resin Composite) were selected for the analysis. Single piece composite material drive shaft has advantage over conventional two-piece steel drive shaft. It has higher specific strength, longer life, less weight, high critical speed and higher torque carrying capacity. The main criteria for drive shaft failure are strength and weight. Maximum modal frequency obtained is 919 Hz. Various harmful vibration modes (lateral vibration and torsional vibration) were identified and maximum deflection region was specified. For single-piece drive shaft the natural bending frequency should be higher because it is subjected to torsion and shear stress. Single piece drive shaft was modelled using Solid Edge and Pro-E. Finite Element Analysis was used for structural and modal analysis with actual running boundary condition like frictional support, torque and moment. FEA simulation results were validated with experimental literature results.

  9. Heat generation caused by ablation of dental restorative materials with an ultra short pulse laser (USPL) system

    Science.gov (United States)

    Braun, Andreas; Wehry, Richard; Brede, Olivier; Frentzen, Matthias; Schelle, Florian

    2011-03-01

    The aim of this study was to assess heat generation in dental restoration materials following laser ablation using an Ultra Short Pulse Laser (USPL) system. Specimens of phosphate cement (PC), ceramic (CE) and composite (C) were used. Ablation was performed with an Nd:YVO4 laser at 1064 nm and a pulse length of 8 ps. Heat generation during laser ablation depended on the thickness of the restoration material. A time delay for temperature increase was observed in the PC and C group. Employing the USPL system for removal of restorative materials, heat generation has to be considered.

  10. Eroded dentin does not jeopardize the bond strength of adhesive restorative materials

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    Janaina Barros Cruz

    2012-08-01

    Full Text Available This in vitro study evaluated the bond strength of adhesive restorative materials to sound and eroded dentin. Thirty-six bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces. Specimens were randomly allocated in 2 groups: sound dentin (immersion in artificial saliva and eroded dentin (pH cycling model - 3× / cola drink for 7 days. Specimens were then reassigned according to restorative material: glass ionomer cement (KetacTM Molar Easy Mix, resin-modified glass ionomer cement (VitremerTM or adhesive system with resin composite (Adper Single Bond 2 + Filtek Z250. Polyethylene tubes with an internal diameter of 0.76 mm were placed over the dentin and filled with the material. The microshear bond test was performed after 24 h of water storage at 37ºC. The failure mode was evaluated using a stereomicroscope (400×. Bond strength data were analyzed with two-way ANOVA and Tukey's post hoc tests (α = 0.05. Eroded dentin showed bond strength values similar to those for sound dentin for all materials. The adhesive system showed the highest bond strength values, regardless of the substrate (p < 0.0001. For all groups, the adhesive/mixed failure prevailed. In conclusion, adhesive materials may be used in eroded dentin without jeopardizing the bonding quality. It is preferable to use an etch-and-rinse adhesive system because it shows the highest bond strength values compared with the glass ionomer cements tested.

  11. Eroded dentin does not jeopardize the bond strength of adhesive restorative materials.

    Science.gov (United States)

    Cruz, Janaina Barros; Lenzi, Tathiane Larissa; Tedesco, Tamara Kerber; Guglielmi, Camila de Almeida Brandão; Raggio, Daniela Prócida

    2012-01-01

    This in vitro study evaluated the bond strength of adhesive restorative materials to sound and eroded dentin. Thirty-six bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces. Specimens were randomly allocated in 2 groups: sound dentin (immersion in artificial saliva) and eroded dentin (pH cycling model - 3× / cola drink for 7 days). Specimens were then reassigned according to restorative material: glass ionomer cement (KetacTM Molar Easy Mix), resin-modified glass ionomer cement (VitremerTM) or adhesive system with resin composite (Adper Single Bond 2 + Filtek Z250). Polyethylene tubes with an internal diameter of 0.76 mm were placed over the dentin and filled with the material. The microshear bond test was performed after 24 h of water storage at 37ºC. The failure mode was evaluated using a stereomicroscope (400×). Bond strength data were analyzed with two-way ANOVA and Tukey's post hoc tests (α = 0.05). Eroded dentin showed bond strength values similar to those for sound dentin for all materials. The adhesive system showed the highest bond strength values, regardless of the substrate (p < 0.0001). For all groups, the adhesive/mixed failure prevailed. In conclusion, adhesive materials may be used in eroded dentin without jeopardizing the bonding quality. It is preferable to use an etch-and-rinse adhesive system because it shows the highest bond strength values compared with the glass ionomer cements tested.

  12. In vitro evaluation of surface roughness and microhardness of restorative materials submitted to erosive challenges.

    Science.gov (United States)

    Briso, A L F; Caruzo, L P; Guedes, A P A; Catelan, A; dos Santos, P H

    2011-01-01

    The aim of this study was to evaluate the effect of different acidic solutions on the microhardness and surface roughness of restorative materials. The 120 specimens of restorative materials (Fuji II LC, Vitremer, Supreme XT, and Supreme XT + Biscover LV) were randomly divided into three groups according to the immersion media: hydrochloric acid, soft drink, or distilled water. Over a period of five weeks, the groups were immersed in the solutions, which were changed weekly. Data were tested using analysis of variance and the Fisher protected least significant difference test (pmicrohardness values before (44.96 ± 2.51 KHN) and after the aging process (41.26 ± 1.22 KHN in water, 35.96 ± 0.81 KHN in soft drink, and 34.74 ± 0.97 KHN in HCl), with significant differences from the other materials (pmicrohardness values were found for glass ionomer materials. The solutions used in this study decreased the microhardness of all studied materials, whereas the sealed surface suffered minor changes in microhardness and surface roughness after exposure to acidic solutions.

  13. Shock absorption capacity of restorative materials for dental implant prostheses: an in vitro study.

    Science.gov (United States)

    Menini, Maria; Conserva, Enrico; Tealdo, Tiziano; Bevilacqua, Marco; Pera, Francesco; Signori, Alessio; Pera, Paolo

    2013-01-01

    To measure the vertical occlusal forces transmitted through crowns made of different restorative materials onto simulated peri-implant bone. The study was conducted using a masticatory robot that is able to reproduce the mandibular movements and forces exerted during mastication. During robot mastication, the forces transmitted onto the simulated peri-implant bone were recorded using nine different restorative materials for the simulated single crown: zirconia, two glass-ceramics, a gold alloy, three composite resins, and two acrylic resins. Three identical sample crowns for each material were used. Each crown was placed under 100 masticatory cycles, occluding with the flat upper surface of the robot to evaluate the vertical forces transmitted. Two-way analysis of variance was used. Alpha was set at .05. The statistical evaluation of the force peaks recorded on the vertical z-axis showed mean values of 641.8 N for zirconia; 484.5 N and 344.5 N, respectively, for the two glass-ceramics; 344.8 N for gold alloy; 293.6 N, 236 N, and 187.4 N, respectively, for the three composite resins; and 39.3 N and 28.3 N, respectively, for the two acrylic resins. Significant differences were found between materials (P material, or gold alloy.

  14. Influence of overlay restorative materials and load cusps on the fatigue resistance of endodontically treated molars.

    Science.gov (United States)

    Magne, Pascal; Knezevic, Alena

    2009-10-01

    To assess the influence of restorative materials and load cusps on the fatigue resistance of endodontically treated molars. Thirty extracted molars received root canal treatment followed by a standardized tooth preparation (3-mm cuspal reduction and immediate dentin sealing). Twenty Cerec 3 overlays (Sirona Dental Systems) were milled in the ceramic Vita MKII block (Vident; groups MKIIGL and MKIIGL-Z, oven-glazed), and 10 restorations were duplicated with a composite resin (Miris 2, Coltane/Whaledent; group M2). The fitting surfaces of the restorations were hydrofluoric acid etched (porcelain only) and silanated. Preparations were airborne-particle abraded and etched. All restorations were luted with preheated Filtek Z100 (3M ESPE) and subjected to cyclic isometric chewing (5 Hz) starting at 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. A stainless steel load sphere was used for groups MKIIGL and M2, while a composite resin load sphere was used in group MKIIGL-Z. All samples were loaded until fracture or to a maximum of 185,000 cycles. Groups were compared using the Kaplan-Meier survival curves (P = .05). None of the molars restored with porcelain withstood all 185,000 loading cycles (survival = 0%). The mean fracture load for MKIIGL was 1,060 N and for MKIIGL-Z, 1,280 N. In group M2, the survival rate was 50%. The rate of fracture below the CEJ was 40%, 30%, and 20% for MKIIGL, MKIIGL-Z, and M2, respectively. Miris 2 overlays showed higher fatigue resistance than MKII porcelain (P = .01) when loaded with a stainless steel antagonist.

  15. Comparison of microleakage from stainless steel crowns margins used with different restorative materials: An in vitro study

    Science.gov (United States)

    Memarpour, Mahtab; Derafshi, Reza; Razavi, Mahshid

    2016-01-01

    Background: Obtaining optimal marginal adaption with prefabricated stainless steel crowns (SSCs) is difficult, especially after removing dental caries or defects in cervical areas. This situation requires the use of an SSC after tooth reconstruction. This study evaluated microleakage and material loss with five restorative materials at SSC margins. Materials and Methods: One hundred and twenty primary molar teeth were randomly divided into six groups (n = 20). Class V cavities were prepared on the buccal surfaces of the teeth in groups 1-5. Cavities were restored with amalgam, resin-based composite, glass ionomer (GI), zinc phosphate, or reinforced zinc oxide eugenol (Zonalin). Group 6 without cavity preparation was used as a control. Restorations with SSCs were prepared according to standard methods. Then, SSCs were fitted so that the crown margins overlaid the restorative materials and cemented with GI. After thermocycling, the specimens were placed in 0.5% fuchsin and sectioned. The proportions of mircoleakage and material loss were evaluated with a digital microscope. Statistical analysis was performed with Kruskal–Wallis and Mann–Whitney tests. Results: The groups differed significantly (P < 0.001). Amalgam and GI showed the least microleakage. Amalgam restorations had significantly less microleakage than the other materials (P < 0.05). Microleakage was greatest with resin-based composite, followed by Zonalin. Material loss was greater in samples restored with Zonalin and zinc phosphate. Conclusion: When SSC margins overlaid the restoration materials, cavity restoration with amalgam or GI before SSC placement led to less microleakage and material loss. Regarding microleakage and material loss, resin-based composite, zinc phosphate, and Zonalin were not suitable options. PMID:26962309

  16. Effect of preheating on the film thickness of contemporary composite restorative materials

    OpenAIRE

    Dimitrios Dionysopoulos; Kosmas Tolidis; Paris Gerasimou; Eugenia Koliniotou-Koumpia

    2014-01-01

    Background/purpose: Recently, the placement of composite materials at an elevated temperature has been proposed in order to increase their flow for better adaptation in cavity walls. The aim of this in vitro study was to evaluate the effect of preheating on the film thickness of a variety of commercially available conventional composites and to compare them with those obtained from a variety of flowable composites at room temperature. Materials and methods: The composites were three nanohy...

  17. Pozzolanic mortars based on waste building materials for the restoration of historical buildings

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    Pašalić Snežana

    2012-01-01

    Full Text Available The environmental aspects of waste building materials have been of great interest in recent years. For the sector of building materials this means increased recycling, reduction of energy consumption and natural resources preservation. This also presents an important contribution in the field of environmental protection. The work deals with the development of pozzolanic mortars made of waste building materials, ground red structure bricks and raw clay materials of inadequate characteristics for the production of ceramic materials. Based on the results of historical mortar characterizations, a group of mortars with specific characteristics (satisfied durability, good compatibility with a historical mortar was prepared. The potential of the waste materials and domestic clay materials application in the production of pozzolanic mortars was confirmed. In addition to the waste management, pozzolanic mortars were designed taking into account the existing conventions in the area of culture heritage.

  18. Matching the optical properties of direct esthetic dental restorative materials to those of human enamel and dentin

    Science.gov (United States)

    Ragain, James Carlton, Jr.

    One of the goals of the restorative dentist is to restore the appearance of the natural dentition. Clinical matching of teeth and restorative materials are seldom accurate and shade selection techniques are subjective. The first specific aim of this research was to characterize the optical absorption and scattering that occurs within enamel, dentin, and composite resin and compomer restorative materials and to relate those phenomena to translucency and color. The second aim was to evaluate small color differences among composite restorative materials which would be detectable by humans. The last aim was to lay the foundation for developing an improved model of specifying layers of dental restorative materials in order to match the translucency and color to those of human enamel. The Kubelka-Munk theory was validated for enamel, dentin, and the restorative materials. These tissues and materials were then characterized in terms of their color parameters. Tooth cores were also characterized in terms of color space parameters. Human subjects were evaluated for their abilities to discriminate small color differences in the dental composite resin materials. The following conclusions were derived from this study: (1) Kubelka-Munk theory accurately predicts the diffuse reflectance spectra of enamel, dentin, and the direct esthetic dental restorative materials studied. (2) Scattering and absorption coefficients of the dental tissues and esthetic restorative materials can be directly calculated from diffuse reflectance measurements of a uniformly thick slab of tissue/material using black and white backings and the appropriate refractive index. (3) For tooth cores, there is a positive correlation between L* and b* and a negative correlation between L* and a*. (4) The range of translucency parameters for the restorative materials studied does not match those of enamel and dentin. (5) None of the shades of the dental composite resin restorative materials studied fit into the

  19. Direct restoration of worn maxillary anterior teeth with a combination of composite resin materials: a case report.

    Science.gov (United States)

    Soares, Carlos José; Pizi, Eliane Cristina Gava; Fonseca, Rodrigo Borges; Martins, Luis Roberto Marcondes; Neto, Alfredo Júlio Fernandes

    2005-01-01

    Tooth loss, alterations on tooth structure, and reduced vertical dimension are known to severely compromise the stomatognathic system. This case report describes the treatment of a patient who presented with an extremely worn maxillary anterior dentition with a loss of posterior support owing to the loss of almost all the posterior teeth, except the mandibular premolars. Provisional removable partial dentures were used to create an optimum maxillomandibular relationship and to provide restorative space prior to the restoration of the remaining teeth. This restoration was accomplished with a combination of layered hybrid and microfilled composite materials, which restored the maxillary anterior teeth to optimum esthetics and function.

  20. The application of methacrylate resin and the derivation as restorative material of damaged tooth tissue

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    Adioro Soetojo

    2007-12-01

    Full Text Available The application of methacrylate resin and the derivation (composite resin and dentin bonding in clinical conservative dentistry has been widely developed. This material could be used to restore class I-V cavity with good aesthetic due to the compatible color with tooth. Composite resin adhesion hydrophobically in enamel that is due to mechanic retention in the form of resin tags which penetrates into enamel porosity. Meanwhile hydrophilic dentin bonding adhesion due to the chemical reaction between functional groups of amino collagen with carbonyl in dentin bonding forming amide binding. In addition mechanical retention in which dentin bonding penetrating into nano inter fibrilar cavity then polymerized. The success of methacrylate resin adhesion restoration is decided by enamel porosity, wetting character of resin, wetting contact angle, good etching acid, optimal humidity of tooth surface, the accuracy of dentist during filling is done etc.

  1. Sealing ability of a new calcium silicate based material as a dentin substitute in class II sandwich restorations: An in vitro study

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    Raji Viola Solomon

    2014-01-01

    Full Text Available Background: Class ll sandwich restorations are routinely performed where conventional Glass ionomer cement (GIC or Resin-modified GIC (RMGIC is used as a base or dentin substitute and a light curing composite resin restorative material is used as an enamel substitute. Various authors have evaluated the microleakage of composite resin restorations where glass ionomer cement has been used as a base in class II sandwich restorations, but a literature survey reveals limited studies on the microleakage analysis of similar restorations with biodentine as a dentin substitute, as an alternative to glass ionomer cement. The aim of this study is: To evaluate the marginal sealing efficacy of a new calcium-silicate-based material (Biodentine as a dentin substitute, at the cervical margins, in posterior class II sandwich restorations.To compare and evaluate the microleakage at the biodentine/composite interface with the microleakage at the resin-modified GIC/composite interface, in posterior class II open sandwich restorations. To compare the efficacy between a water-based etch and rinse adhesive (Scotch bond multipurpose and an acetone-based etch and rinse adhesive (Prime and bond NT, when bonding biodentine to the composite. To evaluate the enamel, dentin, and interfacial microleakage at the composite and biodentine/RMGIC interfaces. Materials and Methods: Fifty class II cavities were prepared on the mesial and distal surfaces of 25 extracted human maxillary third molars, which were randomly divided into five groups of ten cavities each: (G1 Biodentine group, (G2 Fuji II LC GIC group, (G3 Biodentine as a base + prime and bond NT + Tetric N-Ceram composite, (G4 Biodentine + scotchbond multi-purpose + Tetric N-Ceram composite, (G5 Fuji II LC as a base + prime and bond NT+ Tetric-N Ceram composite. The samples were then subjected to thermocycling, 2500× (5°C to 55°C, followed by the dye penetration test. Scores are given from 0 to 3 based on the depth of

  2. Contact with Fluoride-Releasing Restorative Materials Can Arrest Simulated Approximal Caries Lesion

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    Camila de Almeida Brandão Guglielmi

    2015-01-01

    Full Text Available Previous studies have suggested that the presence of white-spot lesion is very probable when adjacent surface is affected by cavitated lesions. This study evaluated the potential of different fluoride-releasing restorative materials in arresting enamel white-spot lesions in approximal surface in contact with them, in vitro (I and in situ (II. White-spot lesions were formed in 240 primary enamel specimens via pH-cycling. They were put in contact with cylindrical blocks of 6 materials (n=20: composite resin, 2 high-viscous glass ionomer cements (HVGIC, resin-modified GIC, resin-modified nanoionomer, and polyacid-modified resin. In both studies I and II, these settings were designed to simulate the contact point between the restoration and simulated approximal lesion. For study I, they were subjected to a new pH-cycling cariogenic challenge for 7 or 14 days (n=10. For study II, a randomized double-blind in situ design was conducted in two phases (7/14 days to promote cariogenic challenge. At the end of both studies, specimens were collected for mineral analysis by cross-sectional microhardness. Higher mineral loss was observed for lesions in contact with resin (p<0.001. HVGICs were the most efficient in preventing mineral loss, whereas other materials presented an intermediate behavior. It is concluded that fluoride-releasing materials can moderately reduce white-spot lesions progression, and HVGIC can arrest enamel lesion in approximal surface in contact with them.

  3. The potential of novel native plant materials for the restoration of novel ecosystems

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    T.A. Jones

    2015-05-01

    Full Text Available Abstract Extensive ecological change has been sustained by many dryland ecosystems throughout the world, resulting in conversion to so-called novel ecosystems. It is within such ecological contexts that native plant materials destined for ecological applications must be able to function. In the Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis [Beetle & A.M. Young] S.L. Welsh ecosystems of the Intermountain West, for example, novel ecosystem structure and functioning are pervasive. Invasive species, particularly annual grasses, fuel repeated wildfires that drive previously stable ecosystem states across thresholds to less desirable states that are highly recalcitrant to restoration efforts. Structural changes include reductions of native flora, damage to biological soil crusts, and alterations to soil microbiota. Functional changes include altered hydrologic and nutrient cycling, leading to permanent losses of soil organic matter and nitrogen that favor the invaders. We argue that there is an important place in restoration for plant materials that are novel and/or non-local that have been developed to be more effective in the novel ecosystems for which they are intended, thus qualifying them as “ecologically appropriate.” Such plant materials may be considered as an alternative to natural/local “genetically appropriate” plant materials, which are sometimes deemed best adapted due to vetting by historical evolutionary processes.

  4. Stress distributions in maxillary central incisors restored with various types of post materials and designs.

    Science.gov (United States)

    Madfa, A A; Kadir, M R Abdul; Kashani, J; Saidin, S; Sulaiman, E; Marhazlinda, J; Rahbari, R; Abdullah, B J J; Abdullah, H; Abu Kasim, N H

    2014-07-01

    Different dental post designs and materials affect the stability of restoration of a tooth. This study aimed to analyse and compare the stability of two shapes of dental posts (parallel-sided and tapered) made of five different materials (titanium, zirconia, carbon fibre and glass fibre) by investigating their stress transfer through the finite element (FE) method. Ten three-dimensional (3D) FE models of a maxillary central incisor restored with two different designs and five different materials were constructed. An oblique loading of 100 N was applied to each 3D model. Analyses along the centre of the post, the crown-cement/core and the post-cement/dentine interfaces were computed, and the means were calculated. One-way ANOVAs followed by post hoc tests were used to evaluate the effectiveness of the post materials and designs (p=0.05). For post designs, the tapered posts introduced significantly higher stress compared with the parallel-sided post (pmaterials, the highest level of stress was found for stainless steel, followed by zirconia, titanium, glass fibre and carbon fibre posts (p<0.05). The carbon and glass fibre posts reduced the stress distribution at the middle and apical part of the posts compared with the stainless steel, zirconia and titanium posts. The opposite results were observed at the crown-cement/core interface.

  5. In vitro fluoride uptake by bovine enamel from aesthetic restorative materials.

    Science.gov (United States)

    Ahiropoulos, Vasilis; Helvatjoglu-Antoniades, Maria; Papadogiannis, Yannis

    2008-07-01

    The purposes of this in vitro study were to determine whether different types of fluoride-containing restoratives produce differing levels of fluoride uptake by bovine enamel, and to determine the effect of time on this uptake. Seven aesthetic restorative materials were evaluated. Forty bovine enamel slabs were prepared for each tested material, five of which were used to determine baseline fluoride concentrations. Each slab was attached to a disc of the tested material and suspended in synthetic saliva for up to 64 days. After removal, the specimens were acid etched with perchloric acid, and the dissolved enamel was analysed for fluoride and calcium. Fluoride was determined by direct potensiometric analysis, whereas the amount of calcium was evaluated by means of atomic absorption spectrophotometry. Higher values of fluoride uptake, not significantly different, were recorded in the first two groups. A statistically significant difference was found in fluoride uptake between Fuji II LC and the three compomers in all test intervals. No significant differences were found in the amounts of fluoride uptake between the three compomers. The highest fluoride uptake from all compomers was recorded by F2000. Enamel acquired significant amounts of fluoride from all materials with variations during the test intervals.

  6. In vitro evaluation of a silica whitening toothpaste containing blue covarine on the colour of teeth containing anterior restoration materials.

    Science.gov (United States)

    Philpotts, Carole J; Cariddi, Eufemia; Spradbery, Paul S; Joiner, Andrew

    2017-08-18

    To investigate the effects of a silica-based whitening toothpaste containing blue covarine on the colour of restorations in extracted human teeth. Human extracted teeth were mounted in acrylic resin. A cavity was cut into the enamel surface and the specimen restored with either glass ionomer or composite dental materials. Following 4 weeks storage in water, specimens were treated with either water, red wine or a toothpaste containing blue covarine (n=10) for 24h followed by brushing with a silica-based toothpaste. Specimens were imaged with a digital imaging system at baseline, after 24h treatment and after brushing with a silica-based toothpaste. CIELAB colour parameters were determined for the restoration and the whole specimen and overall mean colour changes calculated (ΔE). Baseline and post-brushing images were compared subjectively for overall stain and staining around the restoration margin. Red wine produced the largest ΔE values for whole specimens and for all restoration materials and the largest subjective stain scores for whole specimens and restoration margins. The red wine stain was not completely removed by brushing with a silica-based toothpaste. Comparisons of the red wine group with either the blue covarine toothpaste group or the water group were of statistical significance for all parameters (ANOVA, Tukey-Kramer, p0.05) to the water group, for all restoration material types. Exaggerated treatment with a blue covarine containing toothpaste does not significantly affect the colour of the restoration or the restoration margin of the dental materials tested versus a water alone treatment. The silica-based blue covarine containing toothpaste does not permanently stain the restorative materials tested or their margins. Copyright © 2017. Published by Elsevier Ltd.

  7. Influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage restorations.

    Science.gov (United States)

    Bakeman, E M; Rego, N; Chaiyabutr, Y; Kois, J C

    2015-01-01

    This study evaluated the influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage ceramic restorations. Forty extracted molars were allocated into four groups (n=10) to test for two variables: 1) the thickness of ceramic (1 mm or 2 mm) and 2) the ceramic materials (a lithium disilicate glass-ceramic [IPS e.max] or leucite-reinforced glass ceramic [IPS Empress]). All ceramic restorations were luted with resin cement (Variolink II) on the prepared teeth. These luted specimens were loaded to failure in a universal testing machine, in the compression mode, with a crosshead speed of 1.0 mm/min. The data were analyzed using two-way analysis of variance and the Tukey Honestly Significantly Different multiple comparison test (α =0.05). The fracture resistance revealed a significant effect for materials (pceramic was not significant (p=0.074), and the interaction between the thickness of ceramic and the materials was not significant (p=0.406). Mean (standard deviation) fracture resistance values were as follows: a 2-mm thickness of a lithium disilicate bonded to tooth structure (2505 [401] N) revealed a significantly higher fracture resistance than did a 1-mm thickness of leucite-reinforced (1569 [452] N) and a 2-mm thickness of leucite-reinforced ceramic bonded to tooth structure (1716 [436] N) (pceramic at 1-mm thickness (2105 [567] N) and at 2-mm thickness. Using a lithium disilicate glass ceramic for partial coverage restoration significantly improved fracture resistance compared to using a leucite-reinforced glass ceramic. The thickness of ceramic had no significant effect on fracture resistance when the ceramics were bonded to the underlying tooth structure.

  8. Chipping fracture resistance of dental CAD/CAM restorative materials: Part 2. Phenomenological model and the effect of indenter type

    OpenAIRE

    Quinn, G. D.; Giuseppetti, A.A.; Hoffman, K. H.

    2014-01-01

    The edge chipping resistances of six CAD/CAM dental restoration materials are analyzed and correlated to other mechanical properties. A new quadratic relationship that is based on a phenomenological model is presented.

  9. Wear, strength, modulus and hardness of CAD/CAM restorative materials.

    Science.gov (United States)

    Lawson, Nathaniel C; Bansal, Ritika; Burgess, John O

    2016-11-01

    To measure the mechanical properties of several CAD/CAM materials, including lithium disilicate (e.max CAD), lithium silicate/zirconia (Celtra Duo), 3 resin composites (Cerasmart, Lava Ultimate, Paradigm MZ100), and a polymer infiltrated ceramic (Enamic). CAD/CAM blocks were sectioned into 2.5mm×2.5mm×16mm bars for flexural strength and elastic modulus testing and 4mm thick blocks for hardness and wear testing. E.max CAD and half the Celtra Duo specimens were treated in a furnace. Flexural strength specimens (n=10) were tested in a three-point bending fixture. Vickers microhardness (n=2, 5 readings per specimen) was measured with a 1kg load and 15s dwell time. The CAD/CAM materials as well as labial surfaces of human incisors were mounted in the UAB wear device. Cusps of human premolars were mounted as antagonists. Specimens were tested for 400,000 cycles at 20N force, 2mm sliding distance, 1Hz frequency, 24°C, and 33% glycerin lubrication. Volumetric wear and opposing enamel wear were measured with non-contact profilometry. Data were analyzed with 1-way ANOVA and Tukey post-hoc analysis (alpha=0.05). Specimens were observed with SEM. Properties were different for each material (pCAD and Celtra Duo were generally stronger, stiffer, and harder than the other materials. E.max CAD, Celtra Duo, Enamic, and enamel demonstrated signs of abrasive wear, whereas Cerasmart, Lava Ultimate, Paradigm MZ100 demonstrated signs of fatigue. Resin composite and resin infiltrated ceramic materials have demonstrated adequate wear resistance for load bearing restorations, however, they will require at least similar material thickness as lithium disilicate restorations due to their strength. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. Translucency changes of direct esthetic restorative materials after curing, aging and treatment.

    Science.gov (United States)

    Lee, Yong-Keun

    2016-11-01

    The purpose of this article was to review the changes in translucency of direct esthetic restorative materials after curing, aging and treatment. As a criterion for the evaluation of clinical translucency changes, visual perceptibility threshold in translucency parameter difference (ΔTP) of 2 was used. Translucency changes after curing were perceivable depending on experimental methods and products (largest ΔTP in resin composites = 15.9). Translucency changes after aging were reported as either relatively stable or showed perceivable changes by aging protocols (largest ΔTP in resin composites = -3.8). Translucency changes after curing, aging and treatment were perceivable in several products and experimental methods. Therefore, shade matching of direct esthetic materials should be performed considering these instabilities of translucency in direct esthetic materials.

  11. 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.

  12. EFFECT OF DAILY FLUORIDE EXPOSURE ON FLUORIDE RELEASE BY HIGH STRENGTH GLASS IONOMER RESTORATIVE MATERIAL USED WITH ATRAUMATIC RESTORATIVE TECHNIQUE: AN IN VITRO STUDY

    Directory of Open Access Journals (Sweden)

    Hegde Mithra N.

    2012-04-01

    Full Text Available An in-vitro study was done to evaluate the effect of fluoride exposure, fluoride release and recharging capability by High strength Glass Ionomer restorative material used with Atraumatic restorative technique. 20 specimens were divided into four groups of five specimens each. The results showed that High strength Glass ionomer cements (Fuji IX release fluoride, the greatest release takes place between 24- 48 hours.High viscous High Strength Glass ionomer cements have the ability to recharge by external sources like fluoridated dentifrices and varnishes and thus acts as a fluoride reservoir. The recommendation that individuals with a high caries rate and glass ionomer restoration should have fluoride treatment with dentifrice and varnish seems appropriate.

  13. Survey on the teaching and use in dental schools of resin-based materials for restoring posterior teeth.

    Science.gov (United States)

    Liew, Zunliang; Nguyen, Edward; Stella, Rita; Thong, Irene; Yip, Natalia; Zhang, Felix; Burrow, Michael F; Tyas, Martin J

    2011-02-01

    A survey was conducted of 100 dental schools worldwide to investigate the current teaching of posterior resin composite restorations. A 20 multi-part question questionnaire was emailed to the selected schools. Schools were selected by ability to understand and respond in English. The questionnaire consisted of four open-ended questions and 16 closed questions on topics such as material selection for restoring posterior teeth, preclinical teaching of resin composite for posterior teeth, restoration size, contraindications, matrix placement methods, lining use, adhesive selection and finishing. Forty-six schools responded. The outcomes showed all schools included the teaching of resin composite for posterior restorations but varied. The majority of schools (63%) no longer taught amalgam as the preferred posterior restorative material. Half of the schools surveyed set numerical clinical requirements for restoration placement. Australian schools had no requirements whilst 92% of Asian schools did. There was a consensus that larger restorations were less suitable for resin composite. Selection of adhesives depended on region. Generally, the schools surveyed showed minor variations philosophically in teaching of the use and placement of resin composite restorations. © 2011 FDI World Dental Federation.

  14. Fluoride release of six restorative materials in water and pH-cycling solutions

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    Rosa Maria Viana de Bragança Garcez

    2007-10-01

    Full Text Available The fluoride release of restorative materials in deionized water has been the subject of many studies, but the behavior of these materials under conditions of acid challenge that simulates the oral cavity, needs to be further explored. Therefore, the aim of this study was to evaluate the fluoride release of restorative materials in two storage protocols: deionized water and pH-cycling system (demineralizing solution-pH 4.3 and remineralizing solution-pH 7.0 for 15 days. Eight disks of each material (Vitremer™-positive control, Dyract AP, Ariston pHc, Definite®, Tetric®Ceram and Z100-negative control were prepared (11.0 mm x 1.5 mm and suspended individually in 4.0 mL of each solution, which were daily changed. Daily fluoride release was analyzed with an ion specific electrode (Orion 9609 by the direct method or after HMDS-facilitated diffusion, following 1, 7 and 15 days. The values obtained were converted into µgF/mm² and the data analyzed by ANOVA and Tukey's test (p< 0.05. The results showed that all materials released more fluoride in the pH-cycling system, except for Ariston pHc which maintained a constant release during the experiment. The highest fluoride release was presented by the positive control, Vitremer™ in pH-cycling and by Ariston pHc, in deionized water. The negative control Z100 and the resins Definite® and Tetric®Ceram did not present statistically significant differences.

  15. Fracture resistance of endodontically treated teeth restored with short fiber composite used as a core material-An in vitro study.

    Science.gov (United States)

    Garlapati, Tejesh Gupta; Krithikadatta, Jogikalmat; Natanasabapathy, Velmurugan

    2017-03-06

    This in-vitro study tested the fracture resistance of endodontically treated molars with Mesial-Occluso-Distal (MOD) cavities restored with fibre reinforced composite material everX posterior in comparision with hybrid composite and ribbond fiber composite. Fifty intact freshly extracted human mandibular first molars were collected and were randomly divided into five groups (n=10). Group 1: positive control (PC) intact teeth without any endodontic preparation. In groups 2 through 6 after endodontic procedure standard MOD cavities were prepared and restored with their respective core materials as follows: group 2, negative control (NC) left unrestored or temporary flling was applied. Group 3, Hybrid composite (HC) as a core material (Te-Econom Plus Ivoclar Vivadent Asia) group 4, Ribbond (Ribbond; Seattle, WA, USA)+conventional composite resin (RCR) group 5, everX posterior (everX Posterior GC EUROPE)+conventional composite resin (EXP) after thermocycling fracture resistance for the samples were tested using universal testing machine. The results were analysed using ANOVA and Tukey's HSD post hoc tests. Mean fracture resistance (in Newton, N) was group 1: 1568.4±221.71N, group 2: 891.0±50.107N, group 3: 1418.3±168.71N, group 4:1716.7±199.51N and group 5: 1994.8±254.195N. Among the materials tested, endodontically treated teeth restored with everX posterior fiber reinforced composite showed superior fracture resistance. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  16. Cytotoxicity of calcium enriched mixture cement compared with mineral trioxide aggregate and intermediate restorative material.

    Science.gov (United States)

    Mozayeni, Mohammad A; Milani, Amin S; Marvasti, Laleh A; Asgary, Saeed

    2012-08-01

    Calcium enriched mixture (CEM) cement has been recently invented by the last author. It is composed of calcium oxide, calcium phosphate, calcium silicate and calcium sulphate; however, it has a different chemical composition to mineral trioxide aggregate (MTA). The purpose of this ex vivo study was to investigate the cytotoxicity of CEM cement, and compare it with intermediate restorative material (IRM) and MTA. The materials were tested in fresh and set states on L929 fibroblasts to assess their cytotoxicity. The cell viability responses were evaluated with methyl-tetrazolium bromide assay and Elisa reader at 1, 24 and 168 h (7 days). The tested materials were eluted with L929 culture medium according to international standard organisation 109935 standard. Distilled water and culture medium served as positive and negative controls, respectively. Differences in cytotoxicity were evaluated by one-way anova and t-tests. The cytotoxicity of the materials was statistically different at the three time intervals (P IRM subgroups were the most cytotoxic root-end/dental material (P IRM because of lower cytotoxicity. CEM cement also has good biocompatibility as well as lower estimated cost to MTA and seems to be a promising dental material.

  17. Shear Bond Strength of Three Orthodontic Bonding Systems on Enamel and Restorative Materials

    Science.gov (United States)

    Ebeling, Jennifer; Schauseil, Michael; Stein, Steffen; Roggendorf, Matthias; Korbmacher-Steiner, Heike

    2016-01-01

    Objective. The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of two self-etching no-mix adhesives (iBond™ and Scotchbond™) on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT™. Materials and Methods. A total of 270 surfaces (1 enamel and 8 restorative surfaces, n = 30) were randomly divided into three adhesive groups. In group 1 (control) brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2) and Scotchbond Universal adhesive (group 3) were used. The SBS was measured using a Zwicki 1120™ testing machine. The ARI and SBS were compared statistically using the Kruskal–Wallis test (P ≤ 0.05). Results. Significant differences in SBS and ARI were found between the control group and experimental groups. Conclusions. Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain), with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended.

  18. Adhesion of Streptococcus sanguinis to dental implant and restorative materials in vitro.

    Science.gov (United States)

    Hauser-Gerspach, Irmgard; Kulik, Eva M; Weiger, Roland; Decker, Eva-Maria; Von Ohle, Christiane; Meyer, Jürg

    2007-05-01

    Bacterial adhesion to tooth surfaces or dental materials starts immediately upon exposure to the oral environment. The aim of this study, therefore, was to compare the adhesion of Streptococcus sanguinis to saliva-coated human enamel and dental materials - during a one-hour period - using an in vitro flow chamber system which mimicked the oral cavity. After fluorescent staining, the number of adhered cells and their vitality were recorded. The dental materials used were: titanium (Rematitan M), gold (Neocast 3), ceramic (Vita Omega 900), and composite (Tetric Ceram). The number of adherent bacterial cells was higher on titanium, gold, and ceramic surfaces and lower on composite as compared to enamel. As for the percentage of adherent vital cells, it was higher on enamel than on the restorative materials tested. These results suggested that variations in the number and vitality of the adherent pioneer oral bacteria, S. sanguinis, in the in vitro system depended on the surface characteristics of the substratum and the acquired salivary pellicle. The in vitro adhesion model used herein provided a simple and reproducible approach to investigate the impact of surface-modified dental materials on bacterial adhesion and vitality.

  19. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Anda, Markus, E-mail: markusandas@yahoo.com; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

  20. Comparative evaluation of shear bond strength of various esthetic restorative materials to dentin: An in vitro study

    Directory of Open Access Journals (Sweden)

    N Manuja

    2011-01-01

    Full Text Available Aim: To comparatively evaluate the shear bond strength of recent tooth-colored restorative materials to dentin. Materials and Methods: Flat dentinal surface were prepared from 60 caries free, extracted human permanent molars and were mounted in acrylic rings. These were randomly divided into four groups - Group A to Group D, according to the restorative material used i.e. Glass ionomer cement (Fuji IX, Giomer (Beautifil, an Ormocer-based composite (Admira and Nano Ceramic restorative material (Ceram X. These restorative materials were applied on dentinal surface of all the specimens using nylon cylinders. The mounted samples were stored in distilled water for 24 hours and thermocycled. They were then subjected to shear bond strength test using universal testing machine. Data was analyzed using a one-way analysis of variance (ANOVA and student′s ′t′-test. Results: Ceram X (16.63±0.94 MPa and Admira (17.31±0.95 MPa were comparable in their bond strength values, but depicted significantly higher bond strength when compared to Beautifil (12.39±1.05 MPa and Fuji IX (7.76±1.07 MPa. Conclusion: Nano-ceramic and ormocer-based restorative materials showed better bonding potential to dentin as compared to GIC and Giomer.

  1. Bond strength of novel CAD/CAM restorative materials to self-adhesive resin cement: the effect of surface treatments.

    Science.gov (United States)

    Elsaka, Shaymaa E

    2014-12-01

    To evaluate the effect of different surface treatments on the microtensile bond strength (μTBS) of novel CAD/CAM restorative materials to self-adhesive resin cement. Two types of CAD/CAM restorative materials (Vita Enamic [VE] and Lava Ultimate [LU]) were used. The specimens were divided into five groups in each test according to the surface treatment performed; Gr 1 (control; no treatment), Gr 2 (sandblasted [SB]), Gr 3 (SB+silane [S]), Gr 4 (hydrofluoric acid [HF]), and Gr 5 (HF+S). A dual-curing self-adhesive resin cement (Bifix SE [BF]) was applied to each group for testing the adhesion after 24 h of storage in distilled water or after 30 days using the μTBS test. Following fracture testing, specimens were examined with a stereomicroscope and SEM. Surface roughness and morphology of the CAD/CAM restorative materials were characterized after treatment. Data were analyzed using ANOVA and Tukey's test. The surface treatment, type of CAD/CAM restorative material, and water storage periods showed a significant effect on the μTBS (p0.05). On the other hand, for the VE/BF system, surface treatment with HF+S showed higher bond strength values compared with SB and HF surface treatments (pCAD/CAM restorative materials was modified after treatments. The effect of surface treatments on the bond strength of novel CAD/CAM restorative materials to resin cement is material dependent. The VE/BF CAD/CAM material provided higher bond strength values compared with the LU/BF CAD/CAM material.

  2. Use of a visible light-cured periodontal dressing material as a temporary restoration for inlay/onlay preparations.

    Science.gov (United States)

    Apltauer, James J; Silver, Joel; Friedman, Lawrence J; Resnick, Steven J; Berkowitz, Leonard I; Rochlen, Glenn K; Blye, Jeffrey S; Hershkowitz, David H; Berkowitz, Gary S

    2013-01-01

    There are numerous materials that are used as temporaries for inlay and onlay preparations while the permanent restoration is being made. This article looks at 2 types of temporary materials that were placed into inlay or onlay preparations by student dentists: a methylmethacrylate acrylic material (DuraLay Inlay Pattern Resin) and a visible light-cured (VLC) periodontal surgical dressing (Barricaid). The resilience and effectiveness of both products are compared and evaluated for use as temporary restorations in inlay or onlay preparations. The study found that use of the VLC periodontal dressing material offers a novel technique for a quick and efficient method to provide a temporary restoration for various inlay and onlay preparations.

  3. Bond strength of dentin submitted to bleaching and restored with different materials

    Directory of Open Access Journals (Sweden)

    Nelize Marcelino Pessarello

    2012-09-01

    Full Text Available Introduction: The use of adhesive composite resin with fluoride and with greater fluidity can be favorable to the restoration of the palatal/lingual face of teeth submitted to internal bleaching. Objective: This study evaluated the bond strength of adhesive systems and composite resins to bleached dentin. Material and methods: Forty maxillary canines were sectioned to obtain 40 blocks (5 x 5 mm of intracoronary dentin. The fragments were included and bleached with 37% carbamide peroxide. After 7 days, the specimens were divided into two groups according to the adhesive system: with (Optibond Solo Plus and without (Single Bond fluoride and subdivided into 2 subgroups (n = 10 according to the composite resin: microhybrid (Z250 and flowable (Z350. The restoration was carried out through a bipartite matrix. After 24 hours, the specimens were subjected to shear bond strength test. The data (MPa were analyzed by ANOVA and Tukey test (α = 0.05. Results: The best results (p < 0.05 were obtained for fluoridated adhesive (7.44 ± 2.35 compared with that without fluoride (5.36 ± 2.01; flowable resin (7.76 ± 2.23 performed better than microhybrid resin (5.03 ± 1.72. When the two variables were associated, the highest results were obtained for the specimens restored with fluoridated adhesive and flowable resin(9.04 ± 1.92. Lower results were observed for non-fluoridated adhesive + microhybrid resin – control (4.24 ± 1.59, without statistically

  4. Effect of Base and Inlay Restorative Material on the Stress Distribution and Fracture Resistance of Weakened Premolars.

    Science.gov (United States)

    Souza, A C O; Xavier, T A; Platt, J A; Borges, A L S

    2015-01-01

    The purpose of this study was to evaluate the influence of direct base and indirect inlay materials on stress distribution and fracture resistance of endodontically treated premolars with weakened cusps. Forty healthy human premolars were selected; five were left intact as controls (group C+), and the others were subjected to endodontic treatment and removal of buccal and lingual cusp dentin. Five teeth were left as negative controls (group C-). The remaining 30 teeth were divided into two groups according to the direct base material (glass ionomer [GIC] or composite resin [CR]). After base placement, each group was subjected to extensive inlay preparation, and then three subgroups were created (n=5): no inlay restoration (GIC and CR), restored with an indirect composite resin inlay (GIC+IR and CR+IR), and restored with a ceramic inlay (GIC+C and CR+C). Each specimen was loaded until fracture in a universal testing machine. For finite element analysis, the results showed that the removal of tooth structure significantly affected fracture resistance. The lowest values were presented by the negative control group, followed by the restored and based groups (not statistically different from each other) and all lower than the positive control group. In finite element analysis, the stress concentration was lower in the restored tooth compared to the tooth without restoration, whereas in the restored teeth, the stress concentration was similar, regardless of the material used for the base or restoration. It can be concluded that the inlay materials combined with a base showed similar behavior and were not able to regain the strength of intact tooth structure.

  5. Radiopacity of restorative materials using digital images Radiopacidade de materiais restauradores utilizando imagens digitais

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    Leda Maria Pescinini Salzedas

    2006-04-01

    Full Text Available The radiopacity of esthetic restorative materials has been established as an important requirement, improving the radiographic diagnosis. The aim of this study was to evaluate the radiopacity of six restorative materials using a direct digital image system, comparing them to the dental tissues (enamel-dentin, expressed as equivalent thickness of aluminum (millimeters of aluminum. Five specimens of each material were made. Three 2-mm thick longitudinal sections were cut from an intact extracted permanent molar tooth (including enamel and dentin. An aluminum step wedge with 9 steps was used. The samples of different materials were placed on a phosphor plate together with a tooth section, aluminum step wedge and metal code letter, and were exposed using a dental x-ray unit. Five measurements of radiographic density were obtained from each image of each item assessed (restorative material, enamel, dentin, each step of the aluminum step wedge and the mean of these values was calculated. Radiopacity values were subsequently calculated as equivalents of aluminum thickness. Analysis of variance (ANOVA indicated significant differences in radiopacity values among the materials (PA radiopacidade dos materiais tem sido valorizada como importante requisito, incrementando o diagnóstico radiográfico. O objetivo deste estudo foi avaliar, no sistema digital Digora, as densidades radiográficas de 06 materiais restauradores comparando-os aos tecidos dentais (esmalte e dentina, expressos em milímetros de alumínio (mm Al. Foram confeccionadas 05 amostras de cada material e três cortes de um molar extraído hígido (incluindo esmalte e dentina, com 2 mm de espessura, e um penetrômetro de alumínio com 09 degraus. Sobre cada placa óptica foram colocados amostras dos diferentes materiais, um corte do dente humano, o penetrômetro e a identificação, e feita a exposição utilizando um aparelho de raios X. Foram obtidas 05 medidas de densidade radiográfica de

  6. Evaluation of patients with oral lichenoid lesions by dental patch testing and results of removal of the dental restoration material

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    Emine Buket Şahin

    2016-12-01

    Full Text Available Background and Design: Oral lichenoid lesions (OLL are contact stomatitis characterized by white reticular or erosive patches, plaque-like lesions that are clinically and histopathologically indistinguishable from oral lichen planus (OLP. Amalgam dental fillings and dental restoration materials are among the etiologic agents. In the present study, it was aimed to evaluate the standard and dental series patch tests in patients with OLL in comparison to a control group and evaluate our results. Materials and Methods: Thirty-three patients with OLL or OLP and 30 healthy control subjects, who had at least one dental restoration material and/or dental filling, were included in the study. Both groups received standard series and dental patch test and the results were evaluated simultaneously. Results: The most frequent allergens in the dental series patch test in the patient group were palladium chloride (n=4; 12.12% and benzoyl peroxide (n=2, 6.06%. Of the 33 patients with OLL; 8 had positive reaction to allergents in the standard patch test series and 8 had positive reaction in the dental patch test series. There was no significant difference in the rate of patch test reaction to the dental and standard series between the groups. Ten patients were advised to have the dental restoration material removed according to the results of the patch tests. The lesions improved in three patients [removal of all amalgam dental fillings (n=1, replacement of all amalgam dental fillings with an alternative filling material (n=1 and replacement of the dental prosthesis (n=1] following the removal or replacement of the dental restoration material. Conclusion: Dental patch test should be performed in patients with OLL and dental restoration material. Dental filling and/or prosthesis should be removed/replaced if there is a reaction against a dental restoration material-related allergen.

  7. Effect of fluoride-free and fluoridated carbamide peroxide gels on the hardness and surface roughness of aesthetic restorative materials

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    Homayoon Alaghehmand

    2013-01-01

    Full Text Available Background: Bleaching products may show some side effects on soft and hard tissues and restorative materials in the oral cavity. This study evaluated the effect of carbamide peroxide gel with and without fluoride ions on the microhardness and surface roughness of tooth-colored restorative materials. Materials and Methods: In this in-vitro study, 76 cubic specimens (4 mm 3 × 4 mm 3 × 3 mm 3 were fabricated from 4 aesthetic A3-shade restorative materials. These materials consisted of two composite resins and two glass ionomers. The specimens made from each material were treated with the following surface treatments: 1. Control group: The specimens were not bleached and were stored in normal saline. Group 2. Fluoridated 20% carbamide peroxide gel, treated 3 h a day for 4 weeks. Group 3. Treated 1 h a day with fluoride-less 22% carbamide peroxide for two weeks. From each group, three other specimens were selected to be evaluated in terms of changes in surface roughness, under scanning electron microscopy (SEM. Results: In this study, fluoridated 20% carbamide peroxide gel increased the microhardness of the four aesthetic restorative materials. The fluoride-free carbamide peroxide 22% reduced the microhardness of the four used materials, which this change was significant for Vitremer and Amelogen. SEM analyses showed changes in surface roughness of glass ionomer specimens. Conclusion: The effect of bleaching on the microhardness of restorative materials is material dependent. Before the application of bleaching systems on the glass ionomer materials, the application of a protective barrier should be considered.

  8. Microleakage of class V cavities restored with nanofilled resin modified glass ionomer and conventional glass ionomer with self etch adhesive and self etch primer

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    Mansore Mirzaie

    2016-03-01

    Full Text Available Background and Aims: Microleakage is a criterion proposed for assessing the success of any restorative material. Complete seal is difficult especially for dentin margins compared to enamel margins. The aim of this study was to assess the microleakage at the enamel and dentin margins of class V cavities restored by two GIs and two self-etch adhesive systems. Materials and Methods: This study was done on forty third molars. Class V cavities (3×2×2mm were prepared on the buccal and lingual surfaces of teeth using high speed handpiece with 0.8 mm diamond fissure burr. The occlusal margins of the cavities in the enamel and gingival marginswere placed 1 mm below the CEJ. The teeth were divided into 4 groups and the bondings were cured for 20 sec and the teeth were restored. The specimens were kept in distilled water at the temperature of 37°C for 24 hrs. The teeth were thermo cycled and cut in buccolingual direction using diamond disc under water. The dye penetration was evaluated using a stereomicroscope and the leakage was scored. The scores were compared using Kruskal-Wallis test while the paired comparisons were done using Bonferroni correction. P≤0.05 was regarded as significant results. Results: Microleakage scores were similar at the occlusal and gingival walls of all test groups. At the gingival walls, the least microleakage scores were observed. “Fuji IX + SE bond” group showed significant differences with the “Fuji IX + G bond” and “Nanoglass + G bond” groups (P≤0.05. At the occlusal walls, the least scores were observed in the “Fuji IX+SE bond” specimens which were significantly different from the other groups (P≤0.05. Conclusion: Self-Cure glass ionomers yielded less microleakage scores compared to the different types of light-cures due to the less polymerization shrinkage.

  9. New approach in paediatric dentistry: ultrasonic nondestructive evaluation of restorative dental materials. Experimental study.

    Science.gov (United States)

    Ferrazzano, G F; Cantile, T; Coda, M; Ingenito, A

    2015-09-01

    The ultrasonic inspection is a non invasive method which is very developed in the industrial field, for the non-destructive evaluation of materials, and in the medical field, for the ultrasound diagnostic analysis. In paediatric dentistry the most widely used non- destructive evaluation is the X-ray technique. Radiographs are valuable aids in the oral health care of infants, children, adolescents, allowing dentists to diagnose and treat oral diseases that cannot be detected during a visual clinical examination. The aim of this in vitro study was to analyse the ultrasonic non-destructive evaluation (UT-NDE) technique to inspect both dental materials internal structure and the form and position of internal defects in order to obtain a diagnostic method, free of ionising radiations, in paediatric dentistry. Moreover the ultrasonic inspection (UT) could be a rapid method of diagnosis in uncooperative paediatric patients. Study Design: Experimental samples were manufactured with the characteristics of a large composite or glass ionomer cement paediatric dental restoration, in terms of either size or operative technique used. Characteristics of the common restorations were analysed and reproduced in vitro, using the same operative conditions, also adding operative defects into some samples. All the samples were subjected to an innovative UT test using the pulse echo immersion scanning technique. Both C-scans and full volume scans were carried out during the experimental programme. To enhance the data obtained from the UT scan, a digital system (Ecus Inspection software) for signal detection, archiving, processing and displaying was used. UT images showed the presence of internal defects in the dental materials. It was also possible to inspect very thin discontinuity such as the one represented by the fluid resin. In order to execute the statistical analysis, the values of electric voltage measured in five higher white points and in five higher grey points of the pictures

  10. Clinical and radiological evaluation of furcal perforation repaired by mineral trioxide aggregate and intermediate restorative material

    Directory of Open Access Journals (Sweden)

    Kamrun Naher Shomi

    2017-05-01

    Full Text Available The purpose of the present study was to assess the clinical and radiological outcome following repair of furcal perforation by mineral trioxide aggregate (MTA and intermediate restorative material (IRM in mandibular molar teeth. Forty teeth having furcal perforation were enrolled in this study, out of which 20 teeth were treated with MTA and the remaining 20 teeth were subjected to IRM treatment. Following perforation repair, all teeth were subjected to root canal treatment followed by final restoration. Clinical and radiological outcome was evaluated at 3, 6 and 12 months interval. The results showed that in both MTA and IRM groups, pain, tenderness on percussion as well as swelling and sinus was gradually decreased with the increase of the observation period. Furthermore, the widening of the periodontal ligament space and communi-cation with the oral cavity were gradually decreased. Although there was no significant differences between MTA and IRM at 3 and 6 months observation period but at 12 months, the clinical outcome between MTA and IRM was statistically significant (p<0.05. It can be concluded that repair of furcal perforation by MTA showed more effective than that of IRM.

  11. Comparison of chemical composition of materials used in dental restorations 08 years after the irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Mireia Florencio; Santos, Adimir dos, E-mail: mfmaio@ipen.b, E-mail: asantos@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil); Fernandes, Marco A.R., E-mail: marcosrf@salesiano-ata.b [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina

    2009-07-01

    The purpose of this work consisted of quantitative studies of the effects caused by ionizing radiation on the materials commonly used in dental restorations (amalgam, composite resin and Compomer), to mitigate the deleterious effects of radiotherapy when patients with tumors in head and neck, observed when the teeth are restored within the field of radiation. Samples were submitted to the beam of radiation from a source of cobalt-therapy, and analyzed by a X-ray fluorescence technique, by comparing the chemical composition of samples before and after irradiation. Gamma spectrometry was performed with detector of NaI and HPGe in the same samples. Then, the samples were kept in an appropriate place and after 08 years is repeated the same analysis. With these tests, it was possible to verify small changes in the composition of bodies of evidence due to the interaction 08 years after exposure to gamma radiation beams, simulating a patient who develops deleterious effects of radiation after the end radiotherapy treatment. (author)

  12. A Laser-Deposition Approach to Compositional-Spread Discovery of Materials on Conventional Sample Sizes

    Energy Technology Data Exchange (ETDEWEB)

    Christen, Hans M [ORNL; Okubo, Isao [ORNL; Rouleau, Christopher M [ORNL; Jellison Jr, Gerald Earle [ORNL; Puretzky, Alexander A [ORNL; Geohegan, David B [ORNL; Lowndes, Douglas H [ORNL

    2005-01-01

    Parallel (multi-sample) approaches, such as discrete combinatorial synthesis or continuous compositional-spread (CCS), can significantly increase the rate of materials discovery and process optimization. Here we review our generalized CCS method, based on pulsed-laser deposition, in which the synchronization between laser firing and substrate translation (behind a fixed slit aperture) yields the desired variations of composition and thickness. In situ alloying makes this approach applicable to the non-equilibrium synthesis of metastable phases. Deposition on a heater plate with a controlled spatial temperature variation can additionally be used for growth-temperature-dependence studies. Composition and temperature variations are controlled on length scales large enough to yield sample sizes sufficient for conventional characterization techniques (such as temperature-dependent measurements of resistivity or magnetic properties). This technique has been applied to various experimental studies, and we present here the results for the growth of electro-optic materials (Sr{sub x}Ba{sub 1-x}Nb{sub 2}O{sub 6}) and magnetic perovskites (Sr{sub 1-x}Ca{sub x}RuO{sub 3}), and discuss the application to the understanding and optimization of catalysts used in the synthesis of dense forests of carbon nanotubes.

  13. A laser-deposition approach to compositional-spread discovery of materials on conventional sample sizes

    Science.gov (United States)

    Christen, Hans M.; Ohkubo, Isao; Rouleau, Christopher M.; Jellison, Gerald E., Jr.; Puretzky, Alex A.; Geohegan, David B.; Lowndes, Douglas H.

    2005-01-01

    Parallel (multi-sample) approaches, such as discrete combinatorial synthesis or continuous compositional-spread (CCS), can significantly increase the rate of materials discovery and process optimization. Here we review our generalized CCS method, based on pulsed-laser deposition, in which the synchronization between laser firing and substrate translation (behind a fixed slit aperture) yields the desired variations of composition and thickness. In situ alloying makes this approach applicable to the non-equilibrium synthesis of metastable phases. Deposition on a heater plate with a controlled spatial temperature variation can additionally be used for growth-temperature-dependence studies. Composition and temperature variations are controlled on length scales large enough to yield sample sizes sufficient for conventional characterization techniques (such as temperature-dependent measurements of resistivity or magnetic properties). This technique has been applied to various experimental studies, and we present here the results for the growth of electro-optic materials (SrxBa1-xNb2O6) and magnetic perovskites (Sr1-xCaxRuO3), and discuss the application to the understanding and optimization of catalysts used in the synthesis of dense forests of carbon nanotubes.

  14. Effects of erbium-and chromium-doped yttrium scandium gallium garnet and diode lasers on the surfaces of restorative dental materials: a scanning electron microscope study.

    Science.gov (United States)

    Hatipoglu, M; Barutcigil, C

    2015-01-01

    The aim of this study is to evaluate the potential effects of laser irradiation, which is commonly performed in periodontal surgery, on the surfaces of restorative materials. Five different restorative dental materials were used in this study, as follows: (1) Resin composite, (2) poly acid-modified resin composite (compomer), (3) conventional glass ionomer cement (GIC), (4) resin-modified glass ionomer cement (RMGIC), and (5) amalgam. Four cylindrical samples (8 mm diameter, 2 mm height) were prepared for each restorative material. In addition, four freshly extracted, sound human incisors teeth were selected. Two different laser systems commonly used in periodontal surgery were examined in this study: A 810 nm diode laser at a setting of 1 W with continuous-phase laser irradiation for 10 s, and an erbium-and chromium-doped yttrium scandium gallium garnet (Er, Cr: YSGG) laser at settings of 2.5 W, 3.25 W, and 4 W with 25 Hz laser irradiation for 10 s. Scanning electron microscopy (SEM) analysis was performed to evaluate the morphology and surface deformation of the restorative materials and tooth surfaces. According to the SEM images, the Er, Cr: YSGG laser causes irradiation markings that appear as demineralized surfaces on tooth samples. The Er, Cr: YSGG laser also caused deep defects on composite, compomer, and RMGIC surfaces because of its high power, and the ablation was deeper for these samples. High-magnification SEM images of GIC samples showed the melting and combustion effects of the Er, Cr: YSGG laser, which increased as the laser power was increased. In amalgam samples, neither laser left significant harmful effects at the lowest power setting. The diode laser did cause irradiation markings, but they were insignificant compared with those left by the Er, Cr: YSGG laser on the surfaces of the different materials and teeth. Within the limitations of this study, it can be concluded that Er, Cr: YSGG laser irradiation could cause distortions of the surfaces

  15. Comparison of conventional and semilunar coronally positioned flap techniques for root coverage in teeth with cervical abrasion restored with pink resin

    Directory of Open Access Journals (Sweden)

    Santos FR

    2017-03-01

    Full Text Available Felipe Rychuv Santos,1 Carmen Lucia Mueller Storrer,1 Emanuelle Juliana Cunha,1 Lucienne M Ulbrich,1 Camilo Andress Villabona Lopez,2,3 Tatiana Miranda Deliberador1 1Department of Dentistry, Universidade Positivo, Curitiba, Paraná, Brazil; 2Department of Dentistry, University of Santo Tomás, Bucaramanga, Santander, Colombia; 3Department of Implantology, Federal University of Santa Cataria, Florianópolis, Brazil Abstract: Gingival recession is the most common mucogingival defect, characterized by apical migration of the gingival margin from the cementoenamel junction and root exposure. Several surgical techniques are reported for the treatment of gingival recession. Here we present a comparison of the conventional (coronally advanced flap and semilunar coronally positioned flap techniques for root coverage in teeth with cervical abrasion restored with pink resin that mimics the color of the gingiva. Although the conventional technique is more predictable, we found that both techniques were effective in achieving satisfactory and esthetic root coverage. Keywords: gingival recession, root coverage, surgical flaps

  16. Evaluation of Microleakage and Marginal Ridge Fracture Resistance of Primary Molars Restored with Three Restorative Materials: A Comparative in vitro Study.

    Science.gov (United States)

    Yeolekar, Tapan Satish; Chowdhary, Nagalakshmi Ramesh; Mukunda, K S; Kiran, N K

    2015-01-01

    Composite restorations are popular because of their superior esthetics and acceptable clinical performance. But shrinkage is still a drawback. Polymerization shrinkage results in volumetric contraction, leading to deformation of the cusps, microleakage, decrease of marginal adaptation, enamel micro-cracks and postoperative sensitivity. A new class of ring opening resin composite based on silorane chemistry has been introduced with claims of less than 1% shrinkage during polymerization. The present study was conducted to evaluate and compare the ability of low shrink silorane based material, a packable composite and a compomer to resist microleakage in class II restorations on primary molars and evaluate marginal ridge fracture resistance of these materials. Sixty human primary molars were selected. Class II cavities were prepared and the teeth were divided into three groups of twenty each. Groups were as follows group I: low shrink composite resin (Filtek P90). Group II: packable composite (Filtek P60) and Group III: compomer (Compoglass F). Half of the teeth were used for microleakage and the rest for marginal ridge fracture resistance. For microleakage testing, dye penetration method was used with 1% methylene blue dye. Followed by evaluation and grading under stereomicroscope at 10* magnification. Fracture resistance was tested with universal testing machine. It was concluded that low shrink silorane based composite resin showed the least amount of microleakage, whereas compomer showed the highest microleakage. Packable composite resisted fracture of marginal ridge better than other composite resins. Marginal ridge fracture resistance of packable composite was comparable to the intact side. How to cite this article: Yeolekar TS, Chowdhary NR, Mukunda KS, Kiran NK. Evaluation of Microleakage and Marginal Ridge Fracture Resistance of Primary Molars Restored with Three Restorative Materials: A Comparative in vitro Study. Int J Clin Pediatr Dent 2015;8(2):108-113.

  17. An estimation of fluoride release from various dental restorative materials at different pH: In vitro study

    Directory of Open Access Journals (Sweden)

    R N Bahadure

    2012-01-01

    Full Text Available Background: In the mid of 1980s, the cariostatic effect of fluoride ions on enamel caries had been demonstrated in many studies. The use of fluoride releasing dental restorative materials has seen increasing from many years for the specific purpose of leaching of fluoride into the surrounding tissues to inhibit secondary dental caries as well as prevention of caries in the newly erupted tooth. In the dental caries, acidic environment causes the demineralization of tooth structure and also affect the restorative margins of dental restoration. Aim: various restorative materials show different behavior in different pH conditions of oral cavity. Thus, the aim of this study was to evaluate the fluoride release of the various restorative materials at different pH. Design: In this in vitro study, 30 samples of each dental restorative material were prepared and grouped into five with six samples in each group as per the pH of the solution 4.3, 4.6, 5.0, 5.5, and 6.2. All the samples were subjected to alternate cycling of the demineralizing solution (6 h and remineralizing solution (18 h for 15 days. Results: the fluoride release was measured by using fluoride ion specific electrode and digital ion analyzer. The result showed that the fluoride release rate was significantly higher in first day and reduced after third day to nearly constant level. At pH 4.3, the fluoride release was highest and lowest at pH 6.2. Conclusion: the Amalgomer CR showed the highest fluoride release among all the experimental dental restorative materials.

  18. Comparison of the color stability of provisional restorative materials after storing in different drinks

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    Merve Bankoğlu Güngör

    2016-05-01

    Full Text Available OBJECTIVE: The objective of the present study was to compare the color stability of provisional restorative materials after stroring in different drinks. MATERIALS AND METHOD: Thirty specimens (10 mm in diameter and 2 mm in thickness were prepared from three different materials (Temdent, TRIAD ve TelioCAD. Specimens were divided into six groups according to drinks (distilled water, coffee, tea, cola, red wine and fruit juice; n=5. Specimens were stored in these drinks at 37 °C for 48 hours. The L*, a*, b* values of the specimens were measured with a spectrophometer and recorded before and after storing in drinks. Then ΔE* values were calculated. The data were statistically analyzed using two-way analysis of variance (ANOVA and Tukey’s HSD post hoc tests (α=0.05. RESULTS: Difference between the ΔE* values of specimens stored in different drinks was statistically significant (p<0.05. Color change of TelioCAD specimens was smallest in cola drink and greatest in red wine. Color change of Temdent specimens was smallest in fruit juice and greatest in coffee. For TRIAD specimens, greater color change was observed in coffee, red wine, and tea, in descending order. When the results of storing in the same drink were compared, TRIAD showed the greatest values of color change in coffee and red wine in comparison to the other provisional materials (p<0.05. CONCLUSION: Color stability changed according to the type of the provisional material and the drink. When the drinks were evaluated, greater color changes were observed in coffee, and when the materials were evaluated greater color changes were observed in TRIAD.

  19. 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.

  20. Effect of artificial saliva contamination on adhesion of dental restorative materials.

    Science.gov (United States)

    Shimazu, Kisaki; Karibe, Hiroyuki; Ogata, Kiyokazu

    2014-01-01

    The purpose of this study was to evaluate the effects of artificial saliva contamination on three restorative materials, namely, a glass ionomer cement (GIC), a resin-modified GIC (RMGIC), and a composite resin (CR), for which two different etching adhesive systems were used. Thus, three surface conditions were created on bovine teeth using artificial saliva: control, mild saliva contamination, and severe saliva contamination. The dentin bond strength for CR was significantly lower after artificial saliva contamination. There were, however, no significant differences among the three surface conditions in terms of the dentin and enamel bond strengths of GIC and RMGIC. Moreover, CR exhibited significantly greater microleakage after artificial saliva contamination, whereas no significant differences were found in GIC and RMGIC. The results showed that artificial saliva contamination did not affect the shear bond strengths of GIC and RMGIC or their degrees of microleakage.

  1. A 7-year randomized prospective study of a one-step self-etching adhesive in non-carious cervical lesions. The effect of curing modes and restorative material.

    Science.gov (United States)

    van Dijken, Jan W V; Pallesen, Ulla

    2012-12-01

    The aim of this study was to evaluate the clinical retention of a one-step self-etching adhesive system (Xeno III) in Class V non-carious cervical lesions and the effect of restorative material and curing techniques on longevity of the restorations. A total of 139 Class V restorations were placed with the self-etching primer Xeno III and a resin composite (Tetric Ceram) or a poly-acid modified resin composite (Dyract AP) in non-carious cervical lesions without intentional enamel involvement. The materials were cured with a conventional continuous light, a soft-start or a pulse-delay curing mode. The restorations were evaluated at baseline, 6, 12, 18 and 24 months and then yearly during a 7 year follow-up with modified USPHS criteria. Dentine bonding efficiency was determined by the percentage of lost restorations. During the 7 years, 135 restorations could be evaluated. No post-operative sensitivity was reported by the participants. Overall relative cumulative loss rate frequencies for the adhesive system at 6 and 18 months and 7 years, independent of curing technique and restorative material, were 0.8%, 6.9% and 23.0%, respectively. The self-etching adhesive fulfilled at 18 months the full acceptance ADA criteria. Tetric Ceram showed at 7 years a 20.9% loss of retention and Dyract AP a 25.0% loss rate (Log rank p = 0.48). The loss rates for the 3 curing techniques: continuous, soft start and pulse delay were 17%, 27.9% and 24.4%, respectively (Log rank p = 0.52). No secondary caries was observed. The single-step self-etching adhesive showed acceptable clinical long-time retention rates to dentine surfaces independent of restorative material and curing technique used. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Coronal Sealing Capacity of Temporary Restorative Materials in Pediatric Dentistry: A Comparative Study.

    Science.gov (United States)

    Milani, Shabnam; Seraj, Bahman; Heidari, Alireza; Mirdamadi, Atousa; Shahrabi, Mahdi

    2017-01-01

    The aim of this in vitro study is to compare the coronal microleakage of three common temporary restorative materials, namely Coltosol, Compoglass, and Zonalin, used in pediatric dentistry after endodontic treatment at different time intervals (1 week, 1, and 2 months) using dye penetration. Access cavities were prepared in 72 intact extracted premolar teeth. The samples were divided into three groups (n = 24) and filled with Coltosol, Compoglass, or Zonalin. After thermal cycling for 500 cycles (5-55°C), the teeth were immersed in 1% methylene blue dye at 37°C for 1 week (n = 8), 1 month (n = 8), and 2 months (n = 8). The samples were sectioned buccolingually, and the linear depth of dye penetration was measured using a stereomicroscope at 16 × magnification. The data were analyzed using Kruskal-Wallis test. There were no significant differences in the micro-leakage values of Coltosol and Zonalin or Zonalin and Com-poglass groups at 1 week (p > 0.05) or 1 month (p > 0.05) intervals, but a significant difference was noted between Coltosol and Compoglass groups (p 0.05). At 1 week or 1 month of use, Coltosol showed better coronal seal. At 2 months, there was no significant difference apparent between the groups. A longer time lapse was associated with an increased likelihood of microleakage. Milani S, Seraj B, Heidari A, Mirdamadi A, Shahrabi M. Coronal Sealing Capacity of Temporary Restorative Materials in Pediatric Dentistry: A Comparative Study. Int J Clin Pediatr Dent 2017;10(2):115-118.

  3. Effect of fluoride-releasing restorative materials on bacteria-induced pH fall at the bacteria-material interface: an in vitro model study.

    Science.gov (United States)

    Mayanagi, Gen; Igarashi, Koei; Washio, Jumpei; Domon-Tawaraya, Hitomi; Takahashi, Nobuhiro

    2014-01-01

    Inhibition of bacterial acid production by dental restorative materials is one of the strategies for secondary caries prevention. This study aimed to evaluate the effect of fluoride-releasing restorative materials on bacteria-induced pH fall at the bacteria-material interface. Four fluoride-releasing restorative materials, glass-ionomer cement (GIC), resin-modified glass-ionomer cement (RMGIC), resin composite (RC) and flowable resin composite (FRC) were used. Each specimen was immersed in potassium phosphate buffer at pH 7.0 for 10min and 4 weeks, and in potassium acetate buffer at pH 5.5 for 4 weeks. An experimental apparatus was made of polymethyl methacrylate and had a well with restorative materials or polymethyl methacrylate (control) at the bottom. The well was packed with cells of Streptococcus mutans, and the pH at the interface between cells and materials was monitored using a miniature pH electrode after the addition of 1% glucose for 90min, and the fluoride released into the well was quantified using a fluoride ion electrode. The pH of GIC (4.98-5.18), RMGIC (4.77-4.99), RC (4.62-4.75) and FRC (4.54-4.84) at 90min were higher than that of control (4.31-4.49). The fluoride amounts released from GIC were the highest, followed by RMGIC, RC and FRC, irrespective of immersion conditions. Saliva coating on materials had no significant effect. The fluoride-releasing restorative materials inhibited pH fall at the bacteria-material interface. The degree of inhibition of pH fall seemed to correspond to the amount of fluoride detected, suggesting that the inhibition was due to the fluoride released from these materials. A little amount of fluoride actually released from the fluoride-releasing materials may have caries preventive potential for oral bacteria. Copyright © 2013. Published by Elsevier Ltd.

  4. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem.

    Science.gov (United States)

    Anda, Markus; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

  5. Evaluation of marginal leakage of different temporary restorative materials in Endodontics

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    Pedro Henrique Duarte França de Castro

    2013-01-01

    Full Text Available Aim: The aim of this study is to assess the coronal marginal leakage of three temporary restorative materials used for root canal sealing after endodontic treatment. Materials and Methods: A total of 88 single-rooted teeth were submitted to biomechanical preparation and filled by lateral condensation technique. After obturation process, the teeth were randomly separated into four groups, being two teeth of each group used as positive and negative control. Temporary sealing was performed as follows: GI - Clip F (VOCO; GII - Bioplic (Biodinβmica; GIII - Vitremer (3M ESPE and GIV - Ketak N100 (3M ESPE. Next, the specimens were immersed into Indian ink for 30 and 60- days, being 10 specimens for each time interval and then submitted to diaphanization to verify the amount of coronal leakage using a measuring microscope. Results : Leakage mean values within the 30-day period were as follows: Vitremer (0.3 mm, Ketak N100 and Clip F (0.6 mm and Bioplic (1.7 mm. Within the 60-day period, leakage means were 1.1 mm, 1.5 mm, 2.2 mm and 2.6 mm, respectively. Conclusions: None of the materials was capable of preventing marginal leakage within the 30- and 60-day period. In both time intervals, Bioplic presented the highest mean of leakage and Vitremer the lowest.

  6. Fluorides leaching from restorative materials and the effect on adjacent teeth

    DEFF Research Database (Denmark)

    Qvist, Vibeke; Poulsen, Agneta; Teglers, Poul Thorpen

    2010-01-01

    Placing a Class II restoration in a tooth changes the local environment, including that for the adjacent tooth. Apart from the change to a less- or non-cariogenic environment for the restored tooth, the effect of leachable components from a restoration in the adjacent tooth should be taken into c...

  7. Effect of polishing on the microleakage of two different restorative materials in primary teeth: An in vitro study

    Directory of Open Access Journals (Sweden)

    Bhagyashree Salunkhe

    2014-01-01

    Full Text Available Aims and objectives: The aim of this in vitro study was to evaluate the effect of polishing on the microleakage of silorane based Composite (Filtek Z350XT and Resin modified GIC (Vitremer restorations in primary teeth. The objectives were to compare the microleakage with and without polishing, and compare the same between the two materials. Materials and Methods: Class V cavities were prepared on 28 retained deciduous anterior teeth, after they were extracted. The prepared teeth were randomly divided into two groups and restored with the respective materials. The restored teeth were then divided into two subgroups (polished and not polished of seven each. Finishing and polishing for the designated subgroup was done using the Shofu polishing kit. The teeth were then thermocycled and subjected to 1% methylene blue dye penetration, and sectioned buccolingually. Microleakage was evaluated by observing degree of dye penetration under a stereomicroscope, and data subjected to statistical analysis. Statistical analysis was done using Mann-Whitney U test. Results: The results showed that polishing decreased the microleakage in Composite restorations (P0.05. Intergroup comparison of the microleakage without polishing was not significant (P>0.05 while the intergroup comparison after polishing was significant (P<0.05, with polished composite showing comparatively less microleakage. Conclusions: The conclusions of the study were that unpolished restorations with both materials did not show any significant difference in the microleakage scores. Composite restorations, after polishing, showed significantly less microleakage in primary teeth, while with Resin Modified GIC restorations, there wasn′t any difference in microleakage, with or without polishing.

  8. Evaluation of the effect of food and beverages on enamel and restorative materials by SEM and Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Sari, Mustafa Erhan; Erturk, Aliye Gediz; Koyuturk, Alp Erdin; Bekdemir, Yunus

    2014-01-01

    To examine different types of restorative materials used in children as well as primary and permanent teeth enamel when affected by erosive foods. Buttermilk, fruit yoghurt, Coca-cola, fruit juice, Filtek Z-250, Dyract Extra, Fuji II LC, and Fuji IX and tooth enamel were used. Measurements were performed on 1-day, 1-week, 1-month, 3-month, 6-month time periods by using ATR-FTIR technique and surface of the specimens were examined with SEM. Permanent tooth showed the least change among human tooth samples when compared to restorative materials. Among filler materials, the most change was observed in Fuji IX. In terms of beverages the most changes on absorption peaks obtained from spectra were seen on the samples held in Coca-Cola and orange-juice. The exposure of human enamel and restorative materials to acidic drinks may accelerate the degradation process and so reduce the life time of filler materials at equivalent integral exposure times longer than three months. Clinical Relevance Erosive foods and drinks having acidic potential destroy not only tooth enamel but also restorative materials. Copyright © 2013 Wiley Periodicals, Inc.

  9. Measurement of color in different construction materials. The restoration in sandstone buildings

    Directory of Open Access Journals (Sweden)

    García Pascua, N.

    1999-03-01

    Full Text Available The use of construction materials and their subsequent repair purposes include a search of knowledge and preservation of their original appearance. For this reason, the main aim of this study is to determine a color range which does not change with the possible actions on a building, both when restoration works which imply the use and repair of "ancient" materials are carried out, and when construction is carried out with new materials. It is necessary to obtain the quantification of this property in order to check its variation over the passage of time. Each construction material must be taken into account as an isolated problem, since the color is different in each case.

    El empleo de materiales de construcción y la aplicación sobre ellos de productos de reparación requiere un detallado estudio sobre su forma de actuación y la importancia de la conservación del aspecto original de los mismos. Por este motivo, el objetivo principal de este estudio es el determinar un intervalo de color que se conserve a pesar de todas las posibles intervenciones que se acometan en el edificio, tanto cuando se realizan trabajos de restauración, que implican el uso y reparación de materiales "viejos", o bien cuando se llevan a cabo trabajos de construcción con materiales nuevos. Es necesario cuantificar dicha propiedad para poder controlar el paso del tiempo. Cada material de construcción debe ser considerado como un problema aislado, ya que el color es distinto en cada caso.

  10. Adhesion of Streptococcus mutans to Zirconia, Titanium Alloy and some other Restorative Materials: “An in-vitro Study”

    OpenAIRE

    Ezzatollah Jalalian; Shahbaz Naser Mostofi; Elnaz Shafiee; Amin Nourizadeh; Reihaneh Aghajani Nargesi; Sarah Ayremlou

    2015-01-01

    Introduction: Bacterial adhesion on restorative materials may lead to gingival inflammation and secondary caries. Objectives: The aim of this in vitro study was to evaluate the adhesion of streptococcus mutans to zirconia, Feldespatic porcelain, titanium alloy and Indirect composite resin In-vitro. The effect of surface roughness on bacterial adhesion was also studied. Materials and Methods: 10 specimens (5mm diameter, 1mm thickness) of each material, Zirconia, Indirect composite resi...

  11. Fluoride release and uptake capacities of fluoride-releasing restorative materials.

    Science.gov (United States)

    Attar, Nuray; Turgut, Melek D

    2003-01-01

    Many fluoride-releasing dental materials are being sold on the basis of their cariostatic properties. However, the amount fluoride release of these materials is still uncertain. This study investigated the fluoride release and uptake characteristics of four flowable resin composites (Heliomolar Flow, Tetric Flow, Wave, Perma Flo), one flowable compomer (Dyract flow), one conventional glass ionomer cement mixed with two different powder/liquid ratios (ChemFlex Syringeable and ChemFlex Condensable), one packable resin composite (SureFil), one ion-releasing composite (Ariston pHc) and one resin-modified glass ionomer cement (Vitremer). Seven discs (6-mm diameter and 1.5-mm height) were prepared for each material. Each disc was immersed in 3.5 ml of deionized water within a plastic vial and stored at 37 degrees C. The deionized water was changed every 24 hours and the release of fluoride was measured for 30 days. At the end of this period, the samples were recharged with 2 ml of 1.23% acidulated phosphate fluoride (APF) gel for four minutes. Then, all samples were reassessed for an additional 10 days. The fluoride release of all samples was measured with a specific fluoride electrode and an ionanalyzer. Statistical analyses were conducted using two-way repeated measure ANOVA and Duncan's multiple range tests. For all tested materials, the greatest fluoride release was observed after the first day of the study (p0.05). Ariston pHc released the highest amount of fluoride, followed by ChemFlex Syringeable, Vitremer and ChemFlex Condensable. There were statistically significant differences among these materials (p<0.05). Fluoride release of all materials were significantly increased after the first day following refluoridation and Ariston pHc released the greatest among all materials (p<0.01). At the end of two days of refluoridation, the fluoride release rate for each material dropped quickly and stabilized within three days.

  12. Enzymatic responses of human deciduous pulpal fibroblasts to dental restorative materials.

    Science.gov (United States)

    Chen, Chern-Chin; Chen, Robert Cheng-Shen; Huang, Shun-Te

    2002-06-05

    The purpose of this study was to evaluate the responses of succinic dehydrogenase (SDH) and alkaline phosphatase (ALP) activities of human deciduous teeth pulpal fibroblasts (HDPF) to dental restorative materials. Tested materials included Z100 (3M), Dyract (Dentsply), FujiII (GC), and FujiIILC (GC). IRM (Dentsply) and culture medium (MD) alone were used as positive and negative controls, respectively. Specimens 6 mm (diameter) x 3 mm were prepared in accordance with manufacturers' instructions. For light-cured materials, specimens were light cured for 40 s on both sides under a celluloid strip. For chemical-cured materials, specimens were allowed to set at room temperature for 15 min. The specimens were immersed in 1 mL of culture medium without serum for 24 h at room temperature. The extracts were filtered through 0.22-mm filters. HDPF (10,000 cells/well) was incubated with 100 microL of extract and 20 % FBS in a 96-well plate for 24 h in a 37 degrees, 5 % CO(2) incubator. Six wells per material were prepared. Optical density (OD) of SDH and ALP of HDPF were measured by a spectrophotometer. The means were analyzed by ANOVA and then a Duncan Test. The ranking of OD of SDH was IRM IRM materials were cytotoxic to human deciduous pulpal fibroblasts. The cytotoxicity of resin-modified glass ionomer cements (FujiIILC) was stronger than that of traditional glass ionomer cements (FujiII) and composite resin (Z100), and that of compomer (Dyract) was the weakest. On the contrary, ALP activities of resin-modified glass ionomer cements (FujiIILC) and composite resin (Z100) were higher than those of traditional glass ionomer cements (FujiII), while those of compomer (Dyract) were the lowest. It is concluded that, in this study, FujiIILC was the most cytotoxic material and the least inhibitive of ALP activities, Dyract was the weakest cytotoxic material and had the highest inhibition of ALP activities. The rankings of the MTT assay and the ALP assay were not consistent.

  13. Toxicity testing of restorative dental materials using brine shrimp larvae (Artemia salina).

    Science.gov (United States)

    Milhem, Manar M; Al-Hiyasat, Ahmad S; Darmani, Homa

    2008-01-01

    This study investigated the effect of extracts of different composites, glass ionomer cement (GIC)s and compomers on the viability of brine shrimp larvae. Ethanolic extracts of four dental composites (Z-100; Solitaire 2; Filtek P60 and Synergy), a conventional GIC (Ketac-Fil), a resin-modified glass ionomer cement (Vitremer), two compomers (F2000; Dyract AP), and a flowable compomer (Dyract Flow) were prepared from each material. Following evaporation of the ethanol, the extracts were resuspended in distilled water, which was then used to test the effects on the viability of brine shrimp larvae. For the composites, the extract of Synergy was the least toxic (88% viability) followed by the extracts of Solitaire 2, Z100 and P60 (75%, 67.5% and 50% viability, respectively). One-way ANOVA revealed highly significant differences between the resin composite materials (pbrine shrimp larvae followed by GICs and then composites.

  14. Potential Use Of Carbide Lime Waste As An Alternative Material To Conventional Hydrated Lime Of Cement-Lime Mortars

    OpenAIRE

    Al Khaja, Waheeb A.

    1992-01-01

    The present study aimed at the possibility of using the carbide lime waste as an alternative material to the conventional lime used for cement-lime mortar. The waste is a by-product obtained in the generation of acetylene from calcium carbide. Physical and chemical properties of the wastes were studied. Two cement-lime-sand mix proportions containing carbide lime waste were compared with the same mix proportions containing conventional lime along with a control mix without lime. Specimens wer...

  15. Reinforcement of Unsupported Enamel by Restorative Materials and Dentin Bonding Agents: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    T. Rostamzadeh

    2010-06-01

    Full Text Available Objective: Preservation of unsupported occlusal enamel after removal of underlying carious dentin may result in maintenance of aesthetics as well as wear resistance against the opposing enamel. This study investigates the influence of different restorative materialsand bonding agents on reinforcement of unsupported enamel in molars and compares it with sound dentin.Materials and Methods: In this in vitro study, forty- five extracted human molars were selected and randomly divided into five groups of nine. All lingual cusps were cut off. The dentin underlying the buccal cusps was removed in all groups except the positive control.The negative control group received no restorations. After application of varnish and Panavia F, spherical amalgam (Sina and after application of Single-Bond (3M, composite resin (Tetric Ceram was used to replace missing dentin.All specimens were thermocycled, then mounted in acrylic resin using a surveyor. Lingual inclination of facial cusps was positioned horizontally. Load was applied by an Instron machine at a crosshead speed of 10 mm/min until fracture.Data were subjected to ANOVA (one way and Post hoc Test (Duncan.Results: Statistically significant differences were found between the five groups (P<0.001; however, no significant difference was revealed between bonded amalgam and the positive control groups (P=0.762. Composite and amalgam had the same effect (P=0.642, while the composite and negative group had no significant difference(P=0.056.Conclusion: Bonded amalgam systems (Panavia F could reinforce the undermined occlusal enamel effectively.

  16. Marginal microleakage evaluation in class V composite restorations of deciduous teeth prepared conventionally and using Er:YAG laser; Avaliacao da microinfiltracao marginal em cavidades classe V de dentes deciduos preparados com laser Er:YAG e alta rotacao

    Energy Technology Data Exchange (ETDEWEB)

    Pulga, Neusa Vieira Galvao

    2001-07-01

    The evaluation of marginal microleakage in class V restorations of deciduous teeth prepared using Er:laser and comparison to the ones observed when conventionally prepared, using two photopolimerizable materials, composite resin and glass ionomer cement, was the subject of this study. Twenty eight complete deciduous teeth were divided into four groups Group 1 (G1) prepared with high speed drill + composite resin; Group 2 (G2) prepared with high speed drill + glass ionomer cement; Group 3 (G3) prepared using Er:YAG laser (2.94 {mu}m), 300 mJ, 3 Hz, handpiece 2051, energy density 86 mJ/cm{sup 2} + composite resin; Group 4 (G4) prepared using Er:YAG laser (2.94 {mu}m), 300 mJ, 3 Hz, handpiece 2051, energy density 86 J / cm{sup 2} + glass ionomer cement. After the preparation and restoration the specimens where stored at 37 deg C for 24 hours, thermally stressed, immersed in 50% aqueous solution of silver nitrate for 24 hours while kept in the dark. The specimens were rinsed in water, soaked in photodeveloping solution and exposed to fluorescent light for 6 hours. After this process the samples were sectioned and observed by stereomicroscopy. For comparison the groups were divided into occlusive and cervical microleakage. The results were analysed under the Kruskal-Wallis test. For the occlusive microleakage the statistical significance was 5% among the groups and the average comparison showed higher microleakage for G1 (M=35.1) than for G2 (M=24.0) as well as compared to G3 (M=22.3). The other groups did not present statistical differences among them. For the cervical microleakage the Kruskal-Wallis test did not present any statistical difference. Comparing the occlusive and cervical microleakage data, for every group, using the Wilcoxon test, no statistical differences were observed. Concluding, this study showed the Er:YAG laser to be effective for class V restorations and to result in a smaller microleakage degree using the composite resin. These results indicate

  17. Comparative evaluation of shear bond strength and microleakage of tricalcium silicate-based restorative material and radioopaque posterior glass ionomer restorative cement in primary and permanent teeth: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vignesh Guptha Raju

    2014-01-01

    Full Text Available Background: Restoration of carious primary molars is still a major concern while treating the young children that too in deep carious lesion which extends below the cemento-enamel junction (CEJ where pulp protection and achieving adequate marginal seal are very important to prevent secondary caries. The needs were met with the development of new materials. One such of new bioactive material is tricalcium silicate-based restorative material (Biodentine, recommended for restoring deep lesions. Aim: To evaluate and compare shear bond strength and microleakage of tricalcium silicate-based restorative material (Biodentine and glass ionomer cement (Fuji IX GP in primary and permanent teeth. Materials and Methods: Occlusal surface of crowns were ground flat. PVC molds were stabilized over flat dentin surface and filled with tricalcium silicate-based restorative material (Biodentine/glass ionomer cement (Fuji IX GP according to group ascertained. Shear bond strength was evaluated using universal testing machine (INSTRON. Standardized Class II cavities were prepared on both primary and permanent teeth, and then restored with tricalcium silicate-based restorative material (Biodentine/glass ionomer cement (Fuji IX GP according to group ascertained, over which composite resin material was restored using an open sandwich technique. Microleakage was assessed using dye penetration. Microleakage was examined using a stereomicroscope. Results: Results showed that glass ionomer cement (Fuji IX GP exhibited better shear bond strength than tricalcium silicate-based restorative material (Biodentine. Mean microleakage score for glass ionomer cement (Fuji IX GP in permanent teeth was 1.52 and for primary teeth was 1.56. The mean microleakage for tricalcium silicate-based restorative material (Biodentine in permanent teeth was 0.76 and for primary teeth was 0.60. Glass ionomer cement (Fuji IX GP exhibited more microleakage than tricalcium silicate-based restorative

  18. Non-destructive and micro-invasive testing techniques for characterizing materials, structures and restoration problems in mural paintings

    Science.gov (United States)

    Tortora, Mariagrazia; Sfarra, Stefano; Chiarini, Marco; Daniele, Valeria; Taglieri, Giuliana; Cerichelli, Giorgio

    2016-11-01

    In this paper, chemical and structural studies of medieval wall paintings in Ocre (L'Aquila, Italy) are presented. During the latest restoration campaign, non-destructive (Near-Infrared Reflectography and Infrared Thermography) and micro-invasive (Nuclear Magnetic Resonance, Fourier Transform Infrared Spectroscopy, μ-Raman, Scanning Electron Microscopy with X-ray Microanalysis, X-Ray Diffraction, X-Ray Fluorescence, Optical Microscopy, Mass Spectrometry, Thermogravimetry) analyses were performed in order to determine the detachments of wall surfaces and the characterization of original and restoration materials. Data integration allowed to reconstruct the conservative history, the execution techniques and the conservation problems of the artefact, as well as to assess the effectiveness of restoration activities adopted. The combined use of physical and micro-chemical techniques proved to be effective for an in-depth study of materials stratification of paintings.

  19. Comparative evaluation of shear bond strength and microleakage of tricalcium silicate-based restorative material and radioopaque posterior glass ionomer restorative cement in primary and permanent teeth: an in vitro study.

    Science.gov (United States)

    Raju, Vignesh Guptha; Venumbaka, Nilaya Reddy; Mungara, Jayanthi; Vijayakumar, Poornima; Rajendran, Sakthivel; Elangovan, Arun

    2014-01-01

    Restoration of carious primary molars is still a major concern while treating the young children that too in deep carious lesion which extends below the cemento-enamel junction (CEJ) where pulp protection and achieving adequate marginal seal are very important to prevent secondary caries. The needs were met with the development of new materials. One such of new bioactive material is tricalcium silicate-based restorative material (Biodentine), recommended for restoring deep lesions. To evaluate and compare shear bond strength and microleakage of tricalcium silicate-based restorative material (Biodentine) and glass ionomer cement (Fuji IX GP) in primary and permanent teeth. Occlusal surface of crowns were ground flat. PVC molds were stabilized over flat dentin surface and filled with tricalcium silicate-based restorative material (Biodentine)/glass ionomer cement (Fuji IX GP) according to group ascertained. Shear bond strength was evaluated using universal testing machine (INSTRON). Standardized Class II cavities were prepared on both primary and permanent teeth, and then restored with tricalcium silicate-based restorative material (Biodentine)/glass ionomer cement (Fuji IX GP) according to group ascertained, over which composite resin material was restored using an open sandwich technique. Microleakage was assessed using dye penetration. Microleakage was examined using a stereomicroscope. RESULTS showed that glass ionomer cement (Fuji IX GP) exhibited better shear bond strength than tricalcium silicate-based restorative material (Biodentine). Mean microleakage score for glass ionomer cement (Fuji IX GP) in permanent teeth was 1.52 and for primary teeth was 1.56. The mean microleakage for tricalcium silicate-based restorative material (Biodentine) in permanent teeth was 0.76 and for primary teeth was 0.60. Glass ionomer cement (Fuji IX GP) exhibited more microleakage than tricalcium silicate-based restorative material (Biodentine), which was statistically significant

  20. Toxicity Testing of Restorative Dental Materials Using Brine Shrimp Larvae (Artemia salina

    Directory of Open Access Journals (Sweden)

    Manar M. Milhem

    2008-08-01

    Full Text Available This study investigated the effect of extracts of different composites, glass ionomer cement (GICs and compomers on the viability of brine shrimp larvae. Ethanolic extracts of four dental composites (Z-100; Solitaire 2; Filtek P60 and Synergy, a conventional GIC (Ketac-Fil, a resin-modified glass ionomer cement (Vitremer, two compomers (F2000; Dyract AP, and a flowable compomer (Dyract Flow were prepared from each material. Following evaporation of the ethanol, the extracts were resuspended in distilled water, which was then used to test the effects on the viability of brine shrimp larvae. For the composites, the extract of Synergy was the least toxic (88% viability followed by the extracts of Solitaire 2, Z100 and P60 (75%, 67.5% and 50% viability, respectively. One-way ANOVA revealed highly significant differences between the resin composite materials (p<0.001. Follow-up comparison between the composite groups by Tukey's pairwise multiple-comparison test (α =0.05 showed that the extract of Synergy was significantly less toxic than the extracts of all the other materials except that of Solitaire 2. The compomers showed 100% lethality, while the percentage of viable larvae for the extracts of Ketac-Fil, and Vitremer were 32.3%, and 37.0%, respectively. One-way ANOVA revealed highly significant differences between the groups of materials (p<0.001. Follow-up comparison between the groups by Tukey's test (α = 0.05 showed that the toxic effect of the extracts of the compomers were significantly greater than that of Ketac-Fil, and Vitremer. The differences in the toxic effects of Vitremer and Ketac-Fil were not statistically significant. In conclusion, the toxicity of composite materials varied according to their chemical composition. Compomers were the most lethal materials to brine shrimp larvae followed by GICs and then composites.

  1. Laboratory Performance of Universal Adhesive Systems for Luting CAD/CAM Restorative Materials.

    Science.gov (United States)

    Siqueira, Fabiana; Cardenas, Andres Millan; Gutierrez, Mario Felipe; Malaquias, Pâmela; Hass, Viviane; Reis, Alessandra; Loguercio, Alessandro D; Perdigão, Jorge

    To evaluate the microshear bond strength (μSBS) of several universal adhesive systems applied on five different indirect restorative materials. Five CAD/CAM materials were selected: 1) indirect resin composite (LAV); 2) feldspathic glass ceramic (VTR); 3) leucite-reinforced glass-ceramic (EMP); 4) lithium disilicate ceramic (EMX); 5) yttrium-stabilized zirconium dioxide (CZI). For each material, 15 blocks were cut into 4 rectangular sections (6 × 6 × 6 mm) (n = 60 per group), and processed as recommended by the respective manufacturer. For each indirect material, the following adhesive systems were applied according to the respective manufacturer's instructions: 1) AdheSE Universal [ADU]; 2) All-Bond Universal (ABU); 3) Ambar Universal (AMB); 4) Clearfil Universal (CFU); 5) Futurabond U (FBU); 6) One Coat 7 Universal (OCU); 7) Peak Universal Bond (PUB); 8) Prime&Bond Elect (PBE); 9) Scotchbond Universal Adhesive (SBU); 10) Xeno Select (XEN, negative control). After the application of the adhesive system, cylinder-shaped transparent matrices were filled with a dual-curing resin cement (NX3) and light cured. Specimens were stored in water (37°C for 24 h) and tested in shear mode at 1.0 mm/min (mSBS). The failure pattern and μSBS were statistically evaluated (a = 0.05). LAV, VTR, and EMP showed a greater number of cohesive fractures than EMX and CZI (p adhesive for which the mean μSBS reached the highest ranking of statistical significance for all five substrates. When each adhesive was compared across the five substrates, 8 out of 10 (ADU, ABU, AMB, CFU, OCU, PUB, PBE, and SBU) reached the statistically highest mean μSBS when applied on CZI. The specific chemical composition of universal adhesives was not the decisive factor in the bond strength values measured for different CAD/CAM indirect materials. There was a wide variability in mean μSBS when different universal adhesives were applied to the several CAD/CAM indirect materials. Most universal adhesives

  2. Effect of two different polishing systems on fluoride release, surface roughness and bacterial adhesion of newly developed restorative materials.

    Science.gov (United States)

    Bayrak, Gokcen Deniz; Sandalli, Nuket; Selvi-Kuvvetli, Senem; Topcuoglu, Nursen; Kulekci, Guven

    2017-06-15

    To evaluate the effects of two different polishing systems on fluoride release, surface roughness and bacterial adhesion of five restorative materials MATERIALS AND METHODS: The study groups were comprised of five different restorative materials, Beautifil II (B); GCP Glass Fill (G); Amalgomer CR (A); Dyract XP (D); Fuji IX GP (F) and 21 specimens were prepared from each material. Each group was divided into three subgroups according to the polishing system: Mylar (control) (C), Sof-lex (S), and Enhance-Pogo (EP). The amount of fluoride release was measured using a fluoride ion-selective electrode and surface roughness was investigated with a profilometer. Bacterial adhesion on the materials was evaluated by optical density readouts for S.mutans on a spectrophotometer. The highest amount of fluoride was released from specimens in the S subgroup of group G during all measurement days. Surface roughness values were significantly lower in subgroup C than the other polishing systems in all study groups except group G (P material groups in both subgroups (S and EP) (P materials especially in glass ionomer-based materials. Proper polishing systems must be chosen according to the structure and composition of materials to provide the best clinical benefits. Additionally, polishing is necessary for GCP Glass Fill materials following the surface coat and heat application. This article stated that polishing promoted a significant increase of fluoride release on restorative materials especially in glass ionomer-based materials. Further, proper polishing systems must be chosen according to the structure and composition of materials to provide the best clinical benefits in terms of fluoride release, surface roughness and bacterial adhesion. © 2017 Wiley Periodicals, Inc.

  3. Ultrashort pulse laser processing of hard tissue, dental restoration materials, and biocompatibles

    Science.gov (United States)

    Yousif, A.; Strassl, M.; Beer, F.; Verhagen, L.; Wittschier, M.; Wintner, E.

    2007-07-01

    During the last few years, ultra-short laser pulses have proven their potential for application in medical tissue treatment in many ways. In hard tissue ablation, their aptitude for material ablation with negligible collateral damage provides many advantages. Especially teeth representing an anatomically and physiologically very special region with less blood circulation and lower healing rates than other tissues require most careful treatment. Hence, overheating of the pulp and induction of microcracks are some of the most problematic issues in dental preparation. Up till now it was shown by many authors that the application of picosecond or femtosecond pulses allows to perform ablation with very low damaging potential also fitting to the physiological requirements indicated. Beside the short interaction time with the irradiated matter, scanning of the ultra-short pulse trains turned out to be crucial for ablating cavities of the required quality. One main reason for this can be seen in the fact that during scanning the time period between two subsequent pulses incident on the same spot is so much extended that no heat accumulation effects occur and each pulse can be treated as a first one with respect to its local impact. Extension of this advantageous technique to biocompatible materials, i.e. in this case dental restoration materials and titanium plasma-sprayed implants, is just a matter of consequence. Recently published results on composites fit well with earlier data on dental hard tissue. In case of plaque which has to be removed from implants, it turns out that removal of at least the calcified version is harder than tissue removal. Therefore, besides ultra-short lasers, also Diode and Neodymium lasers, in cw and pulsed modes, have been studied with respect to plaque removal and sterilization. The temperature increase during laser exposure has been experimentally evaluated in parallel.

  4. [A comparative study of mechanical properties of materials for custom-made impression trays used by implant-fixed restorations].

    Science.gov (United States)

    Gvetadze, R Sh; Abramian, S V; Rusanov, F S; Nubarian, A P; Ivanov, A A

    2012-01-01

    Materials for custom-made impression trays used for impression by implant fixed restorations were compared in the study. The analysis included such values as flexural strength and elasticity modulus, impression material adhesion strength with the use of adhesive and without it. Light-cured plastic Elite LC Tray had the best rates of bending strength and elasticity modulus and the Protakril M had the highest adhesion strength both with and without adhesive.

  5. Surface Evaluation of Polishing Techniques for New Resilient CAD/CAM Restorative Materials.

    Science.gov (United States)

    Fasbinder, Dennis J; Neiva, Gisele F

    2016-01-01

    The purpose of this study was to measure the surface roughness of milled chairside computer-assisted design/computer assisted machining (CAD/CAM) restorations using several contouring/polishing systems as to their effectiveness for creating a clinically acceptable surface. One hundred onlays were milled from monolithic CAD/CAM blocks with an MCXL milling chamber (Sirona Dental) as follows: 30 resin nano-ceramic (Lava Ultimate, 3M ESPE), 30 hybrid ceramic (Enamic, Vita) and 40 leucite-reinforced ceramic (EmpressCAD, Ivoclar). A single group of EmpressCAD onlays was glazed-fired in a porcelain oven (Programat CS2, Ivoclar). Finishing and polishing systems consisted of either an abrasive-polish technique or a brush-polish technique. Roughness values were measured using a three-dimensional measuring laser microscope (OLS4000 LEXT by Olympus). There was a significant difference in the baseline surface roughness of the CAD/CAM materials (p ≤ 0.05), with the resin nano-ceramic (Lava Ultimate) being smoother than the hybrid ceramic (Enamic), and both being smoother than the leucite-reinforced ceramic (EmpressCAD). All polishing techniques resulted in a smoother surface compared with the baseline surface for the leucite-reinforced ceramic (p ≤ 0.05), with both techniques resulting in a significantly smoother surface than glazing in a porcelain oven (p ≤ 0.05). Both polishing techniques resulted in a smoother surface compared with the baseline surface for both the nano-ceramic and hybrid ceramic materials (p ≤ 0.05). It is possible to create an equally smooth surface for chairside CAD/CAM resilient materials compared with milled ceramics using several finishing and polishing techniques. In general, the polished ceramic surfaces were smoother than the glazed ceramic surfaces. The results of the study indicate that it is possible to create an equally smooth surface for chairside CAD/CAM resilient materials compared with milled ceramics using several

  6. Ensuring the global availability of high-quality dental restorative materials.

    Science.gov (United States)

    Ferracane, J; Fisher, J; Eiselé, J L; Fox, C H

    2013-11-01

    The Minamata Convention, a global legally binding instrument (treaty) on mercury, has been the catalyst for the emerging agenda on global dental materials research. If the current and future challenges of oral health maintenance and healing on a global scale are to be met, a logical and effective research agenda for the discovery and introduction of new, environmentally sustainable, dental materials must be developed through a coordinated effort involving materials scientists, dental clinicians, representatives of industry, members of regional and national regulatory bodies, and advocacy from research organizations. For universal impact, this agenda should be created with awareness of several important ongoing initiatives, such as the WHO non-communicable diseases action plan, the UN sustainable development agenda, and the IADR Global Oral Health In Inequalities Research Agenda (GOHIRA). A significant contributor to this cause is the FDI and its membership, who, through their Vision 2020 initiative, acknowledge their role and responsibility in globally preventing and managing dental disease and providing leadership to the profession in terms of information dissemination and affecting change. Dental researchers also have an obligation to advocate for appropriate funding to match the identified research needs, thus enhancing the possibility that key decision-makers will provide the needed support to achieve the research agenda agreed upon by this diverse group of stakeholders.

  7. Coronal leakage of provisional restorative materials used in endodontics with and without intracanal medication after exposure to human saliva

    Directory of Open Access Journals (Sweden)

    P Udayakumar

    2016-01-01

    Full Text Available Aim: To determine the coronal leakage of various provisional restorations with and without intracanal medication over time after being exposed to human saliva. Materials and Methods: This study investigated Coltosol F, Cavit, Ketac Molar, and IRM as provisional restorative material. Calcium hydroxide and chlorhexidine were used as an intracanal medicament. Ninety-eight single rooted teeth were randomly selected and then mounted in an apparatus that isolated the crown portion of the tooth. Provisional restorative materials were placed in the access cavity following manufacturer guidelines after placement of intracanal medicament. Human saliva and brain heart infusion broth in 3:1 ratio were applied to the samples, incubated at 37°C, and results were tabulated over the course of 4 weeks by the appearance of turbidity in the lower part of the apparatus. Statistical Analysis: The data were statistically analyzed using proportional Z-test. The level of significance was set at 0.05. Results: Coltosol F and Cavit could significantly prevent the bacterial leakage up to a period of 7 days with a P value of 0.01 and 0.005, respectively. Bacterial recontamination was relatively less in the samples treated with intracanal medicaments up to 14 days. After 14 days, however, all materials leaked in over half of the samples. Conclusion: No provisional restorative material can be considered superior in providing a reliable seal after 14 days. Inter-appointments schedule should not extend beyond 2 weeks and after endodontic therapy final restoration should be completed within 1 week.

  8. Longevity of posterior composite restorations: not only a matter of materials

    NARCIS (Netherlands)

    Demarco, F.F.; Correa, M.B.; Cenci, M.S.; Moraes, R.R.; Opdam, N.J.

    2012-01-01

    Resin composites have become the first choice for direct posterior restorations and are increasingly popular among clinicians and patients. Meanwhile, a number of clinical reports in the literature have discussed the durability of these restorations over long periods. In this review, we have searche

  9. Reliability, failure probability, and strength of resin-based materials for CAD/CAM restorations

    Directory of Open Access Journals (Sweden)

    Kiatlin Lim

    Full Text Available ABSTRACT Objective: This study investigated the Weibull parameters and 5% fracture probability of direct, indirect composites, and CAD/CAM composites. Material and Methods: Discshaped (12 mm diameter x 1 mm thick specimens were prepared for a direct composite [Z100 (ZO, 3M-ESPE], an indirect laboratory composite [Ceramage (CM, Shofu], and two CAD/CAM composites [Lava Ultimate (LU, 3M ESPE; Vita Enamic (VE, Vita Zahnfabrik] restorations (n=30 for each group. The specimens were polished, stored in distilled water for 24 hours at 37°C. Weibull parameters (m= modulus of Weibull, σ0= characteristic strength and flexural strength for 5% fracture probability (σ5% were determined using a piston-on-three-balls device at 1 MPa/s in distilled water. Statistical analysis for biaxial flexural strength analysis were performed either by both one-way ANOVA and Tukey's post hoc (α=0.05 or by Pearson's correlation test. Results: Ranking of m was: VE (19.5, LU (14.5, CM (11.7, and ZO (9.6. Ranking of σ0 (MPa was: LU (218.1, ZO (210.4, CM (209.0, and VE (126.5. σ5% (MPa was 177.9 for LU, 163.2 for CM, 154.7 for Z0, and 108.7 for VE. There was no significant difference in the m for ZO, CM, and LU. VE presented the highest m value and significantly higher than ZO. For σ0 and σ5%, ZO, CM, and LU were similar but higher than VE. Conclusion: The strength characteristics of CAD/ CAM composites vary according to their composition and microstructure. VE presented the lowest strength and highest Weibull modulus among the materials.

  10. Reliability, failure probability, and strength of resin-based materials for CAD/CAM restorations

    Science.gov (United States)

    Lim, Kiatlin; Yap, Adrian U-Jin; Agarwalla, Shruti Vidhawan; Tan, Keson Beng-Choon; Rosa, Vinicius

    2016-01-01

    ABSTRACT Objective: This study investigated the Weibull parameters and 5% fracture probability of direct, indirect composites, and CAD/CAM composites. Material and Methods: Discshaped (12 mm diameter x 1 mm thick) specimens were prepared for a direct composite [Z100 (ZO), 3M-ESPE], an indirect laboratory composite [Ceramage (CM), Shofu], and two CAD/CAM composites [Lava Ultimate (LU), 3M ESPE; Vita Enamic (VE), Vita Zahnfabrik] restorations (n=30 for each group). The specimens were polished, stored in distilled water for 24 hours at 37°C. Weibull parameters (m= modulus of Weibull, σ0= characteristic strength) and flexural strength for 5% fracture probability (σ5%) were determined using a piston-on-three-balls device at 1 MPa/s in distilled water. Statistical analysis for biaxial flexural strength analysis were performed either by both one-way ANOVA and Tukey's post hoc (α=0.05) or by Pearson's correlation test. Results: Ranking of m was: VE (19.5), LU (14.5), CM (11.7), and ZO (9.6). Ranking of σ0 (MPa) was: LU (218.1), ZO (210.4), CM (209.0), and VE (126.5). σ5% (MPa) was 177.9 for LU, 163.2 for CM, 154.7 for Z0, and 108.7 for VE. There was no significant difference in the m for ZO, CM, and LU. VE presented the highest m value and significantly higher than ZO. For σ0 and σ5%, ZO, CM, and LU were similar but higher than VE. Conclusion: The strength characteristics of CAD/ CAM composites vary according to their composition and microstructure. VE presented the lowest strength and highest Weibull modulus among the materials.

  11. Effect of type of cavity preparation (bur,Er:YAG laser and restorative materials on prevention of caries lesion

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    Masumeh Hasani Tabatabaei

    2017-03-01

    Full Text Available Background and Aims: Despite the reduction of incidence of dental caries in recent years, this disease is common and many efforts were conducted to decrease the prevalence of dental caries. On the other hand secondary caries lesions are the main reason for replacement of direct restorations. Therefore, the aim of the current study was to evaluate suitable methods of preparation and restorative materials to reduce caries recurrence. Materials and Methods: In this experimental study, eighty human teeth were collected and stored in normal saline. The teeth were soft-tissue debrided and cleaned with water/pumice slurry and rubber cups in a low-speed handpiece. Speciments were randomly divided in two main groups. Cavities were prepared with diamond burs or Er:YAG laser (10 Hz, 300 mJ, 3W. Each group was divided into 4 sub-groups, and restored with a glass-ionomer cement (Fuji IX, resin modified glass-ionomer (Fuji II LC, total etch bonding + composite resin or self-etch bonding + composite resin. The specimens were submitted to pH cycling. Speciments were then sectioned, polished and Vickers microhardness measurements were performed on each specimen. Differences among the medians were analyzed using two way ANOVA test at a 95% confidence level and Tukey test. Results: Statistical analysis showed significant difference in the type of substrate (enamel, dentin in both main groups (P<0.0001 but no differences in the caries lesion development between the cavities restored with the same material and prepared with diamond burs or Er:YAG laser. Conclusion: The Er:YAG laser used for cavity preparation and different types of restorative materials used did not show the ability to guarantee significantly more acid-resistance tooth structure against demineralization.

  12. The use of a masticatory robot to analyze the shock absorption capacity of different restorative materials for implant prosthesis

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    M. Menini

    2011-01-01

    Full Text Available The aim of the present research was to measure in vitro the chewing load forces transmitted through crowns made of different prosthetic restorative materials onto the dental implant. A masticatory robot that is able to reproduce the mandibular movements and the forces exerted during mastication was used. The forces transmitted to the simulated periimplant bone during the robot mastication were analysis of variance (ANOVA was used. The zirconia and the ceramic crowns transmitted significantly greater forces (p-value < 0.0001 than the other crowns tested. Dental materials with lower elastic modulus were better able to ansorb shock from acclusal forces than more rigid materials.

  13. Non-destructive and micro-invasive testing techniques for characterizing materials, structures and restoration problems in mural paintings

    Energy Technology Data Exchange (ETDEWEB)

    Tortora, Mariagrazia, E-mail: Mariagrazia.Tortora@univaq.it [University of L’Aquila, Department of Physical and Chemical Sciences, Via Vetoio (Coppito 1), I-67100, Loc. Coppito, L’Aquila, AQ (Italy); Sfarra, Stefano, E-mail: Stefano.Sfarra@univaq.it [Las.E.R. Laboratory, University of L’Aquila, Department of Industrial and Information Engineering and Economics, Piazzale E. Pontieri 1, I-67100, Loc. Monteluco di Roio, Roio Poggio, L’Aquila, AQ, Italy, (Italy); Chiarini, Marco, E-mail: mchiarini@unite.it [University of Teramo, Department of Bioscience and Technology for Food Agriculture and Environment, Via Carlo Lerici 1, I-64023, Mosciano Sant’Angelo, Teramo, TE, Italy, (Italy); Daniele, Valeria, E-mail: Valeria.Daniele@univaq.it [University of L’Aquila, Department of Industrial and Information Engineering and Economics, Piazzale E. Pontieri 1, I-67100, Loc. Monteluco di Roio, Roio Poggio, L’Aquila, AQ (Italy); Taglieri, Giuliana, E-mail: Giuliana.Taglieri@univaq.it [University of L’Aquila, Department of Industrial and Information Engineering and Economics, Piazzale E. Pontieri 1, I-67100, Loc. Monteluco di Roio, Roio Poggio, L’Aquila, AQ (Italy); Cerichelli, Giorgio, E-mail: Giorgio.Cerichelli@univaq.it [University of L’Aquila, Department of Physical and Chemical Sciences, Via Vetoio (Coppito 1), I-67100, Loc. Coppito, L’Aquila, AQ (Italy)

    2016-11-30

    Highlights: • Infrared thermography allowed to identify structural damage and rising damp effect. • The present approach provided insights on the used pigments and painting techniques. • FT-IR, XRF and XRD analyses of the mortar sample showed the peculiar composition. • 1D, 2D NMR analyses were useful for the identification of the restoration polymer. • NMR technique also allowed to characterize the plasticizing agents. - Abstract: In this paper, chemical and structural studies of medieval wall paintings in Ocre (L’Aquila, Italy) are presented. During the latest restoration campaign, non-destructive (Near-Infrared Reflectography and Infrared Thermography) and micro-invasive (Nuclear Magnetic Resonance, Fourier Transform Infrared Spectroscopy, μ-Raman, Scanning Electron Microscopy with X-ray Microanalysis, X-Ray Diffraction, X-Ray Fluorescence, Optical Microscopy, Mass Spectrometry, Thermogravimetry) analyses were performed in order to determine the detachments of wall surfaces and the characterization of original and restoration materials. Data integration allowed to reconstruct the conservative history, the execution techniques and the conservation problems of the artefact, as well as to assess the effectiveness of restoration activities adopted. The combined use of physical and micro-chemical techniques proved to be effective for an in-depth study of materials stratification of paintings.

  14. Vertical fracture resistance of endodontically treated teeth restored with four sets of obturation and filling materials

    Directory of Open Access Journals (Sweden)

    Mastaneh Javaheri

    2012-06-01

    Conclusions: Composite-resin restorations may recover significantly more fracture resistance than those bonded with amalgam. Resilon-Epiphany may have slightly but not significantly superior results in terms of fracture resistance.

  15. A comparative study of sliding wear of nonmetallic dental restorative materials with emphasis on micromechanical wear mechanisms.

    Science.gov (United States)

    Dupriez, Nataliya Deyneka; von Koeckritz, Ann-Kristin; Kunzelmann, Karl-Heinz

    2015-05-01

    The purpose of this study is to investigate the in vitro tribological behavior of modern nonmetallic restorative materials. Specimen prepared of IPS e.max Press lithium disilicate glass ceramic, IPS Empress Esthetic leucite-reinforced glass ceramic, Everest ZS Blanks yttria-stabilized zirconia and Lava Ultimate composite were subjected to wear using a wear machine designed to simulate occlusal loads. The wear of the investigated materials and antagonists were evaluated by a three-dimensional surface scanner. The quantitative wear test results were used to compare and rank the materials. Specimens were divided into two groups with steatite and alumina antagonists. For each antagonist material an analysis of variance was applied. As a post hoc test of the significant differences, Tukey's honest significant difference test was used. With steatite antagonist: wear of zirconia materials mechanical properties (hardness and fracture toughness) and with materials microstructure. Wear mechanisms are discussed. © 2014 Wiley Periodicals, Inc.

  16. Esthetic smile rehabilitation of anterior teeth by treatment with biomimetic restorative materials: a case report

    Directory of Open Access Journals (Sweden)

    Gouveia TH

    2017-05-01

    Full Text Available Thayla Hellen Nunes Gouveia, Jéssica Dias Theobaldo, Waldemir Francisco Vieira-Junior, Débora Alves Nunes Leite Lima, Flávio Henrique Baggio Aguiar Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Campinas, SP, Brazil Background: In daily clinical practice, esthetics of anterior teeth is a common presenting complaint of patients.Objective: This case report discusses the management of asymmetric smile associated with unsatisfactory extensive composite restorations and describes a clinical protocol using the direct composite resin for smile enhancement to restore the dental harmony of anterior teeth.Methods: The treatment planning was based on a diagnostic wax-up and cosmetic mock-up. After clinical and patient approvals were obtained, the patient was subjected to direct and indirect restorative treatment.Conclusion: Nanocomposites are an effective alternative for anterior teeth restorations. Additionally, good planning enables satisfactory esthetic results, leading to the correction of an inappropriate axial inclination of incisors. Keywords: composite, adhesive, smile, esthetic, restoration

  17. Evaluation of performance of materials used in the ceramic materials restoration of the Plaza de España (Sevilla

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    Alejandre Sánchez, F. J.

    2005-06-01

    Full Text Available Different commercial mortars and stuecos used to cold restore the glazing on deteriorated tile in Seville s Plaza de España were tested for performance and durability. Five types of samples were applied to ceramic bisques and subsequently coloured and protected with resins. The samples were subjected to accelerated weathering consisting in salt crystallization, temperature and relative humidity cycles and ultraviolet radiation. Durability was assessed by visually comparing the effect of salt crystallization, determining the colour parameters with colourimetry and measuring adherence and capillary water absorption. The results obtained were used to differentiate the materials tested in two respects: stucco and protective resin performance under the environmental conditions prevailing in the Plaza de España on the one hand and colour stability on the other.

    En el presente trabajo se estudia el comportamiento y la durabilidad de diferentes morteros y estucos comerciales que se han utilizado para restituir enfrío las pérdidas de vidriado en azulejos deteriorados de la Plaza de España (Sevilla. Para ello se han preparado 5 tipos de muestras que se han aplicado sobre bizcochos cerámicos y que posteriormente se han coloreado y protegido con resinas. Las muestras se han sometido a ensayos de alteración acelerada: cristalización de sales, ciclos de temperatura y humedad relativa, y radiación ultravioleta. La evaluación de la durabilidad se ha llevado a cabo mediante la comparación visual del efecto de cristalización de las sales, la determinación de los parámetros de color mediante colorimetría, de la adherencia y de la absorción de agua por capilaridad. Los resultados obtenidos, permiten realizar una diferenciación en dos aspectos, por un lado, el comportamiento del estuco y su protección para soportar las condiciones medioambientales de la Plaza de España, y, por otro, la estabilidad de los diferentes colores.

  18. Evaluation of patients with oral lichenoid lesions by dental patch testing and results of removal of the dental restoration material

    OpenAIRE

    Emine Buket Şahin; Fatma Çetinözman; Nihal Avcu; Ayşen Karaduman

    2016-01-01

    Background and Design: Oral lichenoid lesions (OLL) are contact stomatitis characterized by white reticular or erosive patches, plaque-like lesions that are clinically and histopathologically indistinguishable from oral lichen planus (OLP). Amalgam dental fillings and dental restoration materials are among the etiologic agents. In the present study, it was aimed to evaluate the standard and dental series patch tests in patients with OLL in comparison to a control group and evaluate our result...

  19. Comparative evaluation of bond strengths of different core materials with various luting agents used for cast crown restorations.

    Science.gov (United States)

    Nayakar, Ramesh P; Patil, Narendra P; Lekha, K

    2012-09-01

    The coronal cast restoration continues to be used commonly to restore mutilated, endodontically treated teeth. The tensile bond strength of luting cements is of critical importance as many of failures are at the core and the crown interface. An invitro study with aim to evaluate and compare bond strengths of luting cements between different core materials and cast crowns. A total of 45 extracted identical mandibular second premolars were endodontically treated and divided into 3 groups of 15 each. Specimens in first group were restored with cast post and core (Group C), and specimens in second group were restored with stainless steel parapost and composite core material (Group B) and specimens in third group were restored with stainless steel parapost and glass ionomer core build (Group G). Standardized crown preparation was done for all the specimens to receive cast crowns. Each group was further divided into 3 subgroups and were cemented using 3 different luting cements namely, resin cement, polycarboxylate cement, glass ionomer cement (Type I). The samples of each subgroup (n = 5) were subjected to tensile testing using Universal Testing Machine at a crosshead speed of 2 mm/min till the dislodgement of crown from the core surface was observed. The bond strengths were significantly different according one way ANOVA (F-150.76 and p < 0.0000). The results of the study showed that the specimens cemented with resin cement in cast core, composite core and glass ionomer core exhibited significantly higher bond strengths as compared to specimens cemented with glass ionomer and polycarboxylate cement. Composite resin core and resin cement combinations were superior to all other cement and core combinations tested.

  20. Biodentine versus Mineral Trioxide Aggregate versus Intermediate Restorative Material for Retrograde Root End Filling: An Invitro Study.

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    Saravanapriyan Soundappan

    2014-04-01

    Full Text Available The aim of this study was to evaluate the marginal adaptation of Biodentine in comparison with Mineral Trioxide Aggregate (MTA and Intermediate Restorative Material (IRM, as a root end filling material, using Scanning Electron Microscopy (SEM.Thirty permanent maxillary central incisors were chemo-mechanically prepared and obturated. Three millimetres of the root end were resected and 3mm retro cavity preparation was done using ultrasonic retrotips. The samples were randomly divided into three groups (n=10 and were restored with root end filling materials: Group I - MTA, Group II - Biodentine, Group III - IRM. The root ends were sectioned transversely at 1mm and 2mm levels and evaluated for marginal adaptation using SEM. The gap between dentin and retro filling material was measured at four quadrants. The mean gap at 1mm level and 2mm level from the resected root tip and combined mean were calculated. The data were statistically analyzed, using one-way ANOVA and Tukey's HSD post hoc test for intergroup analysis and paired t-test for intragroup analysis.The overall results showed no statistically significant difference between MTA and IRM but both were superior when compared to Biodentine. At 1mm level there was no statistically significant difference among any of the tested materials. At 2mm level MTA was superior to both IRM and Biodentine.In overall comparison, MTA and IRM were significantly superior when compared to Biodentine in terms of marginal adaptation, when used as retrograde filling material.

  1. Dental materials for primary dentition: are they suitable for occlusal restorations? A two-body wear study.

    Science.gov (United States)

    Lazaridou, D; Belli, R; Krämer, N; Petschelt, A; Lohbauer, U

    2015-04-01

    This was to evaluate the wear resistance of different materials, compomers, resin-modified glass ionomer cements (RMGICs), glass ionomer cements (GICs), used for posterior restorations in primary teeth and to compare the results with the reference material, amalgam. Eight specimens of each material were subjected to two-body wear test, using a chewing simulator. The wear region of each material was examined under a profilometer, measuring the vertical loss (μm) and the volume loss (mm(3)) of the materials. The results showed significant differences of vertical loss and volume loss of the test materials (p < 0.001). Amalgam had the highest wear resistance. Twinky Star (compomer) had the lowest vertical loss and volume loss. There was no significant difference of vertical loss among compomers, Dyract Extra, Dyract Flow and Dyract Posterior. Riva Self Cure (GIC) had no statistically significant difference compared with the compomers (except Twinky Star). No statistically significant difference was found also between Equia (GIC) and Ketac Moral (GIC) with Dyract Extra (Compomer). RMGICs were found to have the lowest wear resistance. For the statistical analysis, the PASW 20.0 (SPSS Statistics, IBM, Chicago) package was used. Means and standard deviations were measured with descriptive statistics and analyzed using one-way ANOVA. Compomers and some GICs, that have moderate wear resistance, may be sufficient for occlusal restorations in primary dentitions.

  2. Biodentine versus Mineral Trioxide Aggregate versus Intermediate Restorative Material for Retrograde Root End Filling: An Invitro Study.

    Science.gov (United States)

    Soundappan, Saravanapriyan; Sundaramurthy, Jothi Latha; Raghu, Sandhya; Natanasabapathy, Velmurugan

    2014-03-01

    The aim of this study was to evaluate the marginal adaptation of Biodentine in comparison with Mineral Trioxide Aggregate (MTA) and Intermediate Restorative Material (IRM), as a root end filling material, using Scanning Electron Microscopy (SEM). Thirty permanent maxillary central incisors were chemo-mechanically prepared and obturated. Three millimetres of the root end were resected and 3mm retro cavity preparation was done using ultrasonic retrotips. The samples were randomly divided into three groups (n=10) and were restored with root end filling materials: Group I - MTA, Group II - Biodentine, Group III - IRM. The root ends were sectioned transversely at 1mm and 2mm levels and evaluated for marginal adaptation using SEM. The gap between dentin and retro filling material was measured at four quadrants. The mean gap at 1mm level and 2mm level from the resected root tip and combined mean were calculated. The data were statistically analyzed, using one-way ANOVA and Tukey's HSD post hoc test for intergroup analysis and paired t-test for intragroup analysis. The overall results showed no statistically significant difference between MTA and IRM but both were superior when compared to Biodentine. At 1mm level there was no statistically significant difference among any of the tested materials. At 2mm level MTA was superior to both IRM and Biodentine. In overall comparison, MTA and IRM were significantly superior when compared to Biodentine in terms of marginal adaptation, when used as retrograde filling material.

  3. Comparative Study of the Effect of Different Materials Restorative Aesthetic Fluoridated in the Development of Decay in Deciduous Teeth

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    Juliane Mendes de ARAÚJO

    2006-08-01

    Full Text Available Objective: The purpose of this study was to compare the effect of the different materials restorative aesthetic fluoridated in the development of decay in deciduous teeth. Method: For such, 60 deciduous molars were used, us which they were made 60 cavities class V, in the vestibular faces. The samples were divided in 5 groups in an aleatory way and restored with the following materials: Group 1 (Glacier, Group 2 (Vitro Fill LC, Group 3 (Ketac Molar, Group 4 (Vitremer, Group 5 (Freedom. Later, they were exposed ATF with neutral gel. Soon after, they were submitted to the induction of artificial decay by the method of pH cycling, for 14 days. After this period, they were appraised in the microscope of polarized light, being determined the depth of the lesion of external decay, depth and length of the wall lesion. The data were analyzed by the test of Kruskal-Wallis and Mann-Whitney. Results: There were significant differences (p <0,05 in the depth of the lesion it expresses, among RC, RCMP and CIVC, and enter CIVC and the other materials in what refer to the length of the wall lesion. The comparison of the width of the wall lesions showed that CIVC and RC, presented significant differences (p <0,01 when confronted to the other materials. Conclusion: It was conclude that use of the materials fluoridated presented differences with relationship to the inhibition effect of secondary decay, being Ketac Molar the material that presented the best results.

  4. An in vitro microleakage study of class V cavities restored with a new self-adhesive flowable composite resin versus different flowable materials

    OpenAIRE

    Mostafa Sadeghi

    2012-01-01

    Background: Regarding the importance of sealing ability of restorative dental materials, this study was done to assess the microleakage of class V cavities restored with a new self-adhesive flowable composite resin and compare to different flowable materials. Materials and Methods: Seventy standardized class V cavities were prepared on the buccal surface of maxillary premolars teeth. The occlusal and the gingival margins of the cavities were located on the enamel and cementum/dentin, resp...

  5. Materials Design and System Construction for Conventional and New-Concept Supercapacitors.

    Science.gov (United States)

    Wu, Zhong; Li, Lin; Yan, Jun-Min; Zhang, Xin-Bo

    2017-06-01

    With the development of renewable energy and electrified transportation, electrochemical energy storage will be more urgent in the future. Supercapacitors have received extensive attention due to their high power density, fast charge and discharge rates, and long-term cycling stability. During past five years, supercapacitors have been boomed benefited from the development of nanostructured materials synthesis and the promoted innovation of devices construction. In this review, we have summarized the current state-of-the-art development on the fabrication of high-performance supercapacitors. From the electrode material perspective, a variety of materials have been explored for advanced electrode materials with smart material-design strategies such as carbonaceous materials, metal compounds and conducting polymers. Proper nanostructures are engineered to provide sufficient electroactive sites and enhance the kinetics of ion and electron transport. Besides, new-concept supercapacitors have been developed for practical application. Microsupercapacitors and fiber supercapacitors have been explored for portable and compact electronic devices. Subsequently, we have introduced Li-/Na-ion supercapacitors composed of battery-type electrodes and capacitor-type electrode. Integrated energy devices are also explored by incorporating supercapacitors with energy conversion systems for sustainable energy storage. In brief, this review provides a comprehensive summary of recent progress on electrode materials design and burgeoning devices constructions for high-performance supercapacitors.

  6. In Vitro Screening of the Apatite-Forming Ability, Biointeractivity and Physical Properties of a Tricalcium Silicate Material for Endodontics and Restorative Dentistry

    Directory of Open Access Journals (Sweden)

    Maria Giovanna Gandolfi

    2013-12-01

    Full Text Available Aim: Calcium silicate-based materials are hydraulic self-setting materials with physico-chemical properties suitable for endodontic surgery and good biological/clinical outcomes. The study aim was to evaluate the bio-properties (biointeractivity and apatite-forming ability and selected physical properties (porosity, water sorption, solubility, and setting time of Biodentine, a tricalcium silicate material for endodontics and restorative dentistry, compared to that of ProRoot MTA (Mineral Trioxide Aggregate as gold standard material. Methods: Biodentine and ProRoot MTA pastes were prepared and analyzed for calcium release and alkalinizing activity (3 h–28 days, setting time, water sorption, porosity, solubility, surface microstructure and composition, and apatite-forming ability in simulated body fluid. Results: Biodentine showed higher calcium release, alkalinizing activity, and solubility but higher open and apparent porosity, water sorption, and a markedly shorter setting time. Calcium phosphate (CaP deposits were noted on material surfaces after short ageing times. A CaP coating composed of spherulites was detected after 28 days. The thickness, continuity, and Ca/P ratio of the coating differed markedly between the materials. Biodentine showed a coating composed by denser but smaller spherulites, while ProRoot MTA showed large but less dense aggregates of spherulitic deposits. Conclusions: Biodentine showed a pronounced ability to release calcium and extended alkalinizing activity interlinked with its noticeable porosity, water sorption, and solubility: open porosities provide a broad wet biointeractive surface for the release of the calcium and hydroxyl ions involved in the formation of a CaP mineral. Biodentine is a biointeractive tricalcium silicate material with interesting chemical-physical properties and represents a fast-setting alternative to the conventional calcium silicate MTA-like cements.

  7. Finite element modeling of dental restoration through multi-material laser densification

    Science.gov (United States)

    Dai, Kun

    To provide guidance for intelligent selection of various parameters in the Multi-Material Laser Densification (MMLD) process for dental restorations, finite element modeling (FEM) has been carried out to investigate the MMLD process. These modeling investigations include the thermal analysis of the nominal surface temperature that should be adopted during experiments in order to achieve the desired microstructure; the effects of the volume shrinkage due to transformation from a powder compact to dense liquid on the temperature distribution and the size of the transformation zone; the evolution of transient temperature, transient stresses, residual stresses and distortions; and the effects of laser processing conditions, such as fabrication sequences, laser scanning patterns, component sizes, preheating temperatures, laser scanning rates, initial porosities, and thicknesses of each powder layer, on the final quality of the component fabricated via the MMLD process. The simulation results are compared with the experiments. It is found that the predicted temperature distribution matches the experiments very well. The nominal surface temperature applied on the dental porcelain body should be below 1273 K to prevent the forming of the un-desired microstructure (i.e., a leucite-free glassy phase). The simplified models that do not include the volume shrinkage effect provide good estimations of the temperature field and the size of the laser-densified body, although the shape of the laser-densified body predicted is different from that obtained in the experiment. It is also fount that warping and residual thermal stresses of the laser-densified component are more sensitive to the chamber preheating temperature and the thickness of each powder layer than to the laser scanning rate and the initial porosity of the powder layer. The major mechanism responsible for these phenomena is identified to be related to the change of the temperature gradient induced by these laser

  8. Historical and Material Approach to the Paintings at the Portugal National Library: Contributions to the History of Conservation and Restoration of Easel Painting in the 19th Century

    OpenAIRE

    SOARES, C. M.; Rodrigues, R. M.; Cruz, A. J.; Rego, C.

    2012-01-01

    There are in the National Library of Portugal (BNP) about fifty paintings from former convents, mainly portraits executed between the sixteenth and nineteenth centuries, which are hung in rooms and along corridors, far from the eyes of the public and simultaneously protected by recent conservation and restoration interventions. These paintings, of little artistic interest, are, however, individual cases for the study of conservation and restoration interventions made in the nineteenth century...

  9. Bacteriology of deep carious lesions underneath amalgam restorations with different pulp-capping materials - an in vivo analysis

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    Prasanna Neelakantan

    2012-04-01

    Full Text Available Microorganisms remaining in dentin following cavity preparation may induce pulp damage, requiring the use of pulp-capping agents with antimicrobial activity underneath permanent restorations. OBJECTIVE: The aims of this study were to analyze the bacteriological status of carious dentin and to assess the efficacy of different base underneath silver amalgam restorations. MATERIAL AND METHODS: This study was conducted on 50 patients aged 13 to 30 years. Sterile swabs were used to take samples after cavity preparation, which was assessed by microbiological culture to identify the microorganisms present. Following this, cavities were restored with silver amalgam, using one of the materials being investigated, as the base: calcium hydroxide (Group II, polyantibiotic paste (Group III, a novel light-cured fluoride-releasing hydroxyapatite-based liner (Group IV and mineral trioxide aggregate - MTA (Group V. In Group I, the cavities were restored with silver amalgam, without any base. After 3 months, the amalgam was removed and samples taken again and analyzed for the microbial flora. RESULTS: Lactobacilli were the most commonly isolated microorganisms in the samples of carious dentin. Groups IV and V showed negative culture in the 3-month samples. There was no statistically significant difference between Groups I, II and III. There was no significant difference between Groups IV and V (p>0.05. Both Groups IV and V showed significantly better results when compared to Groups I, II and III (p<0.05. CONCLUSIONS: The hydroxyapatite-based liner and MTA performed significantly better in terms of antibacterial activity than the other materials.

  10. Bacteriology of deep carious lesions underneath amalgam restorations with different pulp-capping materials - an in vivo analysis

    Science.gov (United States)

    NEELAKANTAN, Prasanna; RAO, Chandragiri Venkata Subba; INDRAMOHAN, Jamuna

    2012-01-01

    Microorganisms remaining in dentin following cavity preparation may induce pulp damage, requiring the use of pulp-capping agents with antimicrobial activity underneath permanent restorations. Objective The aims of this study were to analyze the bacteriological status of carious dentin and to assess the efficacy of different base underneath silver amalgam restorations. Material and Methods This study was conducted on 50 patients aged 13 to 30 years. Sterile swabs were used to take samples after cavity preparation, which was assessed by microbiological culture to identify the microorganisms present. Following this, cavities were restored with silver amalgam, using one of the materials being investigated, as the base: calcium hydroxide (Group II), polyantibiotic paste (Group III), a novel light-cured fluoride-releasing hydroxyapatite-based liner (Group IV) and mineral trioxide aggregate - MTA (Group V). In Group I, the cavities were restored with silver amalgam, without any base. After 3 months, the amalgam was removed and samples taken again and analyzed for the microbial flora. Results Lactobacilli were the most commonly isolated microorganisms in the samples of carious dentin. Groups IV and V showed negative culture in the 3-month samples. There was no statistically significant difference between Groups I, II and III. There was no significant difference between Groups IV and V (p>0.05). Both Groups IV and V showed significantly better results when compared to Groups I, II and III (p<0.05). Conclusions The hydroxyapatite-based liner and MTA performed significantly better in terms of antibacterial activity than the other materials. PMID:22666827

  11. Materials Design and System Construction for Conventional and New‐Concept Supercapacitors

    Science.gov (United States)

    Wu, Zhong; Li, Lin

    2017-01-01

    With the development of renewable energy and electrified transportation, electrochemical energy storage will be more urgent in the future. Supercapacitors have received extensive attention due to their high power density, fast charge and discharge rates, and long‐term cycling stability. During past five years, supercapacitors have been boomed benefited from the development of nanostructured materials synthesis and the promoted innovation of devices construction. In this review, we have summarized the current state‐of‐the‐art development on the fabrication of high‐performance supercapacitors. From the electrode material perspective, a variety of materials have been explored for advanced electrode materials with smart material‐design strategies such as carbonaceous materials, metal compounds and conducting polymers. Proper nanostructures are engineered to provide sufficient electroactive sites and enhance the kinetics of ion and electron transport. Besides, new‐concept supercapacitors have been developed for practical application. Microsupercapacitors and fiber supercapacitors have been explored for portable and compact electronic devices. Subsequently, we have introduced Li‐/Na‐ion supercapacitors composed of battery‐type electrodes and capacitor‐type electrode. Integrated energy devices are also explored by incorporating supercapacitors with energy conversion systems for sustainable energy storage. In brief, this review provides a comprehensive summary of recent progress on electrode materials design and burgeoning devices constructions for high‐performance supercapacitors. PMID:28638780

  12. Temperature changes under demineralized dentin during polymerization of three resin-based restorative materials using QTH and LED units

    Directory of Open Access Journals (Sweden)

    Sayed-Mostafa Mousavinasab

    2014-08-01

    Full Text Available Objectives Light-curing of resin-based materials (RBMs increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs of three different RBMs using quartz tungsten halogen (QTH and light-emitting diode (LED units (LCUs. Materials and Methods Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12 during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey, a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE, and a giomer (Beautifil II, Shofu GmbH, was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. Results The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p 0.05. Conclusions Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

  13. The Market Gate of Miletus: damages, material characteristics and the development of a compatible mortar for restoration

    Science.gov (United States)

    Siegesmund, Siegfried; Middendorf, Bernhard

    2008-12-01

    The indoor exhibit of the Market Gate of Miletus is unique for an archaeological monument. The reconstruction of the gate was done in such a way that most marble fragments were removed leaving cored marble columns 3-4 cm in thickness. These cored columns were mounted on a steel construction and filled with different mortars or filled with specially shaped blocks of brick combined with mortar. All the missing marble elements were replaced by copies made of a Portland cement based concrete, which is compositionally similar to the original building materials. During the Second World War the monument was heavily damaged by aerial bombardment. For 2 years the Market Gate of Miletus was exposed to weathering, because a brick wall protecting the gate was also destroyed. The deterioration phenomena observed are microcracks, macroscopic fractures, flaking, sugaring, greying, salt efflorescence, calcitic-sinter layers and iron oxide formation etc. The rapid deterioration seems to be due to indoor atmospheric effects, and also by a combination of incompatible materials (e.g. marble, steel, mortar, concrete, bricks etc.). Compatible building materials like mortars or stone replacing materials have to be developed for the planned restoration. The requirements for restoration mortars are chemical-mineralogical and physical-mechanical compatibilities with the existing building materials. In detail this means that the mortar should ensure good bonding properties, adapted strength development and not stain the marble when in direct contact. The favoured mortar was developed with a hydraulic binder based on iron-free white cement and pozzolana based on activated clay. A special limestone and quartz sand mixture was used as an aggregate. The cement was adjusted using chemical additives. Specially designed tests were applied extensively to prove whether the developed mortar is suitable for the restoration of this precious monument.

  14. Amino acid derivative-mediated detoxification and functionalization of dual cure dental restorative material for dental pulp cell mineralization.

    Science.gov (United States)

    Minamikawa, Hajime; Yamada, Masahiro; Iwasa, Fuminori; Ueno, Takeshi; Deyama, Yoshiaki; Suzuki, Kuniaki; Yawaka, Yasutaka; Ogawa, Takahiro

    2010-10-01

    Current dental restorative materials are only used to fill the defect of hard tissues, such as dentin and enamel, because of their cytotoxicity. Therefore, exposed dental pulp tissues in deep cavities must be first covered by a pulp capping material like calcium hydroxide to form a layer of mineralized tissue. However, this tissue mineralization is based on pathological reaction and triggers long-lasting inflammation, often causing clinical problems. This study tested the ability of N-acetyl cysteine (NAC), amino acid derivative, to reduce cytotoxicity and induce mineralized tissue conductivity in resin-modified glass ionomer (RMGI), a widely used dental restorative material having dual cure mechanism. Rat dental pulp cells were cultured on untreated or NAC-supplemented RMGI. NAC supplementation substantially increased the percentage of viable cells from 46.7 to 73.3% after 24-h incubation. Cell attachment, spreading, proliferative activity, and odontoblast-related gene and protein expressions increased significantly on NAC-supplemented RMGI. The mineralization capability of cells, which was nearly suppressed on untreated RMGI, was induced on NAC-supplemented RMGI. These improved behaviors and functions of dental pulp cells on NAC-supplemented RMGI were associated with a considerable reduction in the production of intracellular reactive oxygen species and with the increased level of intracellular glutathione reserves. These results demonstrated that NAC could detoxify and functionalize RMGIs via two different mechanisms involving in situ material detoxification and antioxidant cell protection. We believe that this study provides a new approach for developing dental restorative materials that enables mineralized tissue regeneration.

  15. The effects of ambient temperature and mixing time of glass ionomer cement material on the survival rate of proximal ART restorations in primary molars

    Directory of Open Access Journals (Sweden)

    Arthur M Kemoli

    2014-01-01

    Full Text Available Objective: Temperature fluctuations and material mixing times are likely to affect the consistency and integrity of the material mixture, and hence the restoration made out of it. The purpose of the present study was to determine the influence of the ambient temperature and the mixing time of glass ionomer cement (GIC restorative material on the survival rate of proximal atraumatic restorative treatment (ART restorations placed in primary molars. Materials and Methods: A total of 804 restorations were placed in the primary molars of 6-8-year-olds using the ART approach. The restorations were then followed for a period of 2 years and evaluated at given intervals. The data collected were analyzed using SPSS computer statistical program, and the results tested and compared using the Chi-square, Kaplan Meier survival analysis and Cox Proportional hazard statistical tests. Results: The cumulative survival rate of the restorations dropped from the initial 94.4% to 30.8% at the end of 2 years. The higher survival rate of the restorations was associated with the experienced operators and assistants when using the rubber dam isolation method. However, there was no statistically significant difference in the survival rate of the restorations when related to the room temperature and the mixing time of the GIC materials used in spite of the variations in the temperature recoded and the methods used in mixing the materials. Conclusion: The ambient temperature and mixing time of GIC did not have a significant effect on the survival of the proximal ART restorations.

  16. Reflections on the conservation and the conservative restoration of archive and library materials

    Directory of Open Access Journals (Sweden)

    Antonio Zappalà

    2004-02-01

    Full Text Available Some aspects concerning the situation of the archive-library sector are analyzed, highlighting all the weaknesses in the organization of the libraries and of the archives, weaknesses in the actions aimed at prevention and safeguarding and effects of restoration on aging.

  17. Evaluation of performance of materials used in the ceramic materials restoration of the Plaza de España (Sevilla)

    OpenAIRE

    Alejandre Sánchez, F. J.; Villegas Sánchez, R.; Jurado Pérez, M.

    2005-01-01

    Different commercial mortars and stuecos used to cold restore the glazing on deteriorated tile in Seville s Plaza de España were tested for performance and durability. Five types of samples were applied to ceramic bisques and subsequently coloured and protected with resins. The samples were subjected to accelerated weathering consisting in salt crystallization, temperature and relative humidity cycles and ultraviolet radiation. Durability was assessed by visually comparing the effect of salt ...

  18. Sustained Ocular Delivery of Ciprofloxacin Using Nanospheres and Conventional Contact Lens Materials

    Science.gov (United States)

    Garhwal, Rahul; Shady, Sally F.; Ellis, Edward J.; Ellis, Jeanne Y.; Leahy, Charles D.; McCarthy, Stephen P.; Crawford, Kathryn S.

    2012-01-01

    Purpose. To formulate conventional contact lenses that incorporate nanosphere-encapsulated antibiotic and demonstrate that the lenses provide for sustained antibacterial activity. Methods. A copolymer composed of pullulan and polycaprolactone (PCL) was used to synthesize core-shell nanospheres that encapsulated ciprofloxacin. Bactericidal activity of the nanosphere-encapsulated ciprofloxacin (nanosphere/cipro) was tested by using liquid cultures of either Staphylococcus aureus or Pseudomonas aeruginosa. Nanosphere/cipro was then incorporated into HEMA-based contact lenses that were tested for growth inhibition of S. aureus or P. aeruginosa in liquid cultures inoculated daily with fresh bacteria. Lens designs included thin or thick lenses incorporating nanosphere/cipro and ciprofloxacin-HCl-soaked Acuvue lenses (Acuvue; Johnson & Johnson Vision Care, Inc., Jacksonville, FL). Results. Less than 2 μg/mL of nanosphere/cipro effectively inhibited the proliferation of cultures inoculated with 107 or 108 bacteria/mL of S. aureus and P. aeruginosa, respectively. HEMA-based contact lenses polymerized with nanosphere/cipro were transparent, effectively inhibited the proliferation of greater than 107/mL of bacteria added daily over 3 days of culture, and killed up to 5 × 109 total microbes in a single inoculation. A thicker lens design provided additional inhibition of bacterial growth for up to 96 hours. Conclusions. Core-shell nanospheres loaded with an antibiotic can be incorporated into a conventional, transparent contact lens and provide for sustained and effective bactericidal activity and thereby provide a new drug delivery platform for widespread use in treating ocular disorders. PMID:22266514

  19. Alternatives to Conventional Construction Materials on Landfills. A Guide; Alternativa konstruktionsmaterial paa deponier. Vaegledning

    Energy Technology Data Exchange (ETDEWEB)

    Rihm, Thomas; Rogbeck, Yvonne; Svedberg, Bo; Eriksson, Maria

    2009-03-15

    Before a landfill can be sited, an application for a permit from the authorities is required. Already in the application process the consequences concerning impact on human health and on the environment must be described, including descriptions of e.g. bottom liners and capping constructions. Since there is a long period of time between when the permit is given and when the capping will be carried out, it is common practice, either to postpone decisions concerning capping details, or to delegate the decisions to the supervisory authorities to be made at a later stage. All constructions must however be approved by the authorities before they can be carried out. A construction must fulfil the demands for its function. For the capping this means that the percolation through it must be low, even in a long time perspective. A construction may not in itself cause adverse environmental effects, e.g. leaching of hazardous substances from the construction material. Thus, there are functional as well as environmental demands. Beside the functional demands given in the Swedish legislation, notably in the ordinance on landfilling, the construction must be physically stable, also in a long time perspective. The materials in the construction must have sufficient strength, and may not change over time, e.g. due to degradation, which could lead to malfunction. Demands on environmental behaviour can be divided into two parts. Humans and animals must be kept from direct contact with dangerous substances including dermal contact, inhalation of dust or gases and oral intake of soil, plants or berries. Secondly, dangerous substances may not be spread with surface or ground water to an extent that could lead to adverse effects on human health or on the environment. The impact on the environment is not only depending of the materials being used, but also on the construction design, where in the landfill the construction is situated and, not least, how the landfill is located. It is

  20. Comparative evaluation of compressive strength and flexural strength of conventional core materials with nanohybrid composite resin core material an in vitro study.

    Science.gov (United States)

    Jayanthi, Narasimha; Vinod, V

    2013-09-01

    Several dental materials have been used for core build-up procedures. Most of these materials were not specifically developed for this purpose, but as a consequence of their properties, have found application in core build-up procedures. Improvements in composites and the development of nanocomposites have led to their use as a core build up material due to their superior mechanical properties, optical properties and ease of handling. However it is not clear if they have better mechanical properties than the conventional core build up materials like amalgam, GIC and dual cure composite core build up material. The strength of the core material is very important and this study was undertaken to compare the mechanical properties of materials used for direct core foundations. The differences between the compressive strength and flexural strength of Filtek Z350 nanocomposite with conventional core build up materials like Amalgam, Vitremer GIC and Fluorocore were tested. Cylindrical plexi glass split molds of dimension 6 ± 1 mm [height] x4 ± 1 mm [diameter] were used to fabricate 15 samples of each core material for testing the compressive strength and rectangular plexi glass split molds of dimension 25 ± 1 mm [length] x 2 ± 1 mm[height] x2 ± 1 mm [width] used for fabricating samples for flexural strength. The samples were stored a water bath at 250 °C for 24 h before testing. The samples were tested using a Universal Instron testing machine. The results of the study showed that Fluorocore had the highest compressive strength and flexural strength followed by Filtek Z350 [nanocomposite] Amalgam had the least flexural strength and Vitremer GIC had the least compressive strength. Thus flurocore and nanocomposite are stronger than other core build up materials and hence should be preferred over other conventional core build up materials in extensively damaged teeth.

  1. Advanced combined application of micro-X-ray diffraction/micro-X-ray fluorescence with conventional techniques for the identification of pictorial materials from Baroque Andalusia paintings.

    Science.gov (United States)

    Herrera, L K; Montalbani, S; Chiavari, G; Cotte, M; Solé, V A; Bueno, J; Duran, A; Justo, A; Perez-Rodriguez, J L

    2009-11-15

    The process of investigating paintings includes the identification of materials to solve technical and historical art questions, to aid in the deduction of the original appearance, and in the establishment of the chemical and physical conditions for adequate restoration and conservation. In particular, we have focused on the identification of several samples taken from six famous canvases painted by Pedro Atanasio Bocanegra, who created a very special collection depicting the life of San Ignacio, which is located in the church of San Justo y Pastor of Granada, Spain. The characterization of the inorganic and organic compounds of the textiles, preparation layers, and pictorial layers have been carried out using an XRD diffractometer, SEM observations, EDX spectrometry, FT-IR spectrometry (both in reflection and transmission mode), pyrolysis/gas chromatography/mass spectrometry and synchrotron-based micro-X-ray techniques. In this work, the advantages over conventional X-ray diffraction of using combined synchrotron-based micro-X-ray diffraction and micro-X-ray fluorescence in the identification of multi-layer paintings is demonstrated.

  2. Comparative in vitro assessment of color stability of hybrid esthetic restorative materials against various children′s beverages

    Directory of Open Access Journals (Sweden)

    Kavita Hotwani

    2014-01-01

    Full Text Available Purpose: The present study was aimed to evaluate and compare the color stability of two hybrid tooth-colored restorative materials, namely, resin-modified glass ionomer cement (GC Fuji II LC Capsules - GC Corporation, Tokyo, Japan and giomer (Beautifil II - Shofu Inc, Kyoto, Japan when subjected to immersion in various children′s beverages. Materials and Methods: Standardized disc specimens were prepared using the test restorative materials. After preparation and rehydration of the specimens, baseline color evaluations were performed using spectrophotometer. The readings were recorded according to CIELAB color space. The experimental groups were further subdivided for immersion in orange juice, bournvita milk, and coke. Subsequent to immersion and pH cycling, new color evaluations were carried out after 1 week and 4 weeks for all the experimental groups. The mean color change values were calculated. Results: The obtained data was subjected to statistical analysis. The results indicated that giomer specimens exhibited less color change as compared to RMGIC specimens indicating better color stability. The maximum color changes were found with the use of coke for a period of 4 weeks. Conclusion: Amongst the two materials, giomer showed less color changes as compared to RMGIC indicating a better color stability.

  3. Characterization of set Intermediate Restorative Material, Biodentine, Bioaggregate and a prototype calcium silicate cement for use as root-end filling materials.

    Science.gov (United States)

    Grech, L; Mallia, B; Camilleri, J

    2013-07-01

    To investigate the composition of materials and leachate of a hydrated prototype cement composed of tricalcium silicate and radiopacifier and compare this to other tricalcium silicate-based cements (Biodentine and Bioaggregate) to assess whether the additives in the proprietary brand cements affect the hydration of the materials, using Intermediate Restorative Material (IRM), a standard root-end filling material as a control. The materials investigated included a prototype-radiopacified tricalcium silicate cement, Biodentine, Bioaggregate and Intermediate Restorative Material (IRM). The pH and calcium ion concentration of the leachate were investigated. The hydrated cements were characterized using scanning electron microscopy (SEM) and X-ray energy dispersive analysis (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). All the cements tested were alkaline. The tricalcium silicate-based cements leached calcium in solution. Scanning electron microscopy of the prototype-radiopacified tricalcium silicate cement, Biodentine and Bioaggregate displayed hydrating cement grains, surrounded by a matrix composed of calcium silicate hydrate and calcium hydroxide. The presence of calcium hydroxide was evident from the XRD plots. FT-IR indicated the occurrence of a poorly crystalline calcium silicate hydrate. Biodentine displayed the presence of calcium carbonate. Bioaggregate incorporated a phosphate-containing phase. IRM consisted of zinc oxide interspersed in an organic matrix. The hydration of prototype-radiopacified tricalcium silicate cement, Biodentine and Bioaggregate resulted in the formation of calcium silicate hydrate and calcium hydroxide, which was leached in solution. The hydrated materials were composed of a cementitous phase that was rich in calcium and silicon and a radiopacifying material. Biodentine included calcium carbonate, and Bioaggregate included silica and calcium phosphate in the powders. IRM was composed of zinc oxide

  4. Laboratory Investigations of the High Temperature Corrosion of Various Materials in Simulated oxy-fuel and Conventional Coal Firing

    Energy Technology Data Exchange (ETDEWEB)

    Folkeson, N.; Pettersson, J.; Svensson, J.E. [Chalmers Univ. of Technology (Sweden); Hjornhede, A. [Vattenfall Power Consultant AB (Sweden); Montgomery, M. [Vattenfall Heat Nordic/DTU Mekanik (Denmark); Bjurman, M. [Vattenfall Research and Development AB (Sweden)

    2009-07-01

    Laboratory exposures in horizontal tube furnaces were conducted to test various materials for corrosion resistance in simulated oxy-fuel firing and conventional coal firing environments. Two different exposures were done at 630 C for 672 hours. The reaction atmosphere, consisting of CO{sub 2}, H{sub 2}O, O{sub 2}, N{sub 2} and SO{sub 2}, was mixed to resemble that of oxy-fuel firing in the first exposure and that of conventional coal firing in the second exposure (N{sub 2} was added during the second exposure only). Four different materials were tested in the first exposure; Sanicro 63, Alloy 800HT, 304L and 304HCu. In the second exposure four different materials were tested; 304L, Alloy 800HT, Kanthal APMT and NiCrAl. Apart from cleaned sample coupons, some samples pre-exposed in a test rig under oxy-fuel conditions with lignite as fuel and some pre-exposed with bituminous coal as fuel were investigated in the first exposure. In the second exposure some samples were pre-exposed in a rig under conventional firing conditions with lignite as fuel. The corrosion attack on the investigated samples was analysed by gravimetry, x-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive x-ray (EDX). The SEM/EDX analysis was made on both the sample envelope and metallographic cross sections of the samples. The results show that there is small difference in the corrosion attack between the two environments. There was also little difference in oxide morphology and composition between cleaned samples and pre-exposed samples of the same material. The austenitic chromia former 304HCu suffered the most extensive corrosion attack in the oxy-fuel environment. In the conventional air firing environment 304L showed the highest mass gain. Chromia formers with higher chromium concentrations performed better, especially the super austenitic Alloy 800HT, with its high chromium concentration, formed a thin and protective corundum type oxide. The nickel based

  5. Translucency of esthetic dental restorative CAD/CAM materials and composite resins with respect to thickness and surface roughness.

    Science.gov (United States)

    Awad, Daniel; Stawarczyk, Bogna; Liebermann, Anja; Ilie, Nicoleta

    2015-06-01

    Little information is available about the translucency of monolithic CAD/CAM materials. The purpose of this study was to evaluate the translucency of restorative CAD/CAM materials and direct composite resins with respect to thickness and surface roughness. In total, 240 disk-shaped specimens (12×14×1 mm and 12×14×2 mm) of 3 different CAD/CAM glass ceramics (CELTRA Duo, IPS e.max CAD, IPS Empress CAD), a fine-structure feldspathic ceramic (VITA Mark II), a hybrid ceramic (VITA Enamic), a resin nanoceramic composite resin (LAVA Ultimate), an experimental (CAD/CAM nanohybrid composite resin), 2 interim materials (Telio CAD; VITA CAD-Temp), and 3 direct composite resins (Tetric EvoCeram; Filtek Supreme XTE; Tetric EvoCeram Bulk Fill) were fabricated (n=10). After 3 different surface pretreatments (polished, rough SiC P1200, or SiC P500), absolute translucency and surface roughness were measured using spectrophotometry and tactile profilometry. The influence of material type, thickness, and roughness on absolute translucency was analyzed using a multivariate analysis, 1-way ANOVA, and the Tukey HSD post hoc test (P<.05). Pearson correlations and statistical hypothesis tests were used to assess the results (P<.05). The effect of all tested parameters was significant among the materials (P<.05). The greatest influence on the measured translucency was thickness (partial eta squared ηP²=.988), closely followed by material (.982), and the pretreatment method (.835). The surface roughness was strongly influenced by the pretreatment method (.975) and type of material (.941). Thickness and surface roughness are major factors affecting the absolute translucency of adhesively luted restorations. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  6. FE Simulation Modelling and Exergy Analysis of Conventional Forging Deformation Behaviour of Material Processing

    Directory of Open Access Journals (Sweden)

    Santosh Sanodiya

    2017-03-01

    Full Text Available The present paper examines the deformation behaviour of geometrical specimens of an aluminium alloy undergoing axial compression in a Universal Testing Machine under dry condition. It is observed that researchers have made attempts to investigate alternate specimens for friction calibration. It is found that ring compression test is recommended as the standard test for determination of coefficient of friction, because it gives reliable results. The effect of weight percentage of silicon carbide on microstructure, hardness and upsetting load is studied. The friction factor at die metal interface is evaluated by ring compression tests and its effect on non-uniform deformation is investigated. The experimental results are finally compared with those obtained by FEA simulation and modelling. In order to validate the predictability of these specimens, real experiments on them are carried out. Rings of standard dimensional ratio 6:3:1 in the same machine. Friction predictions from both specimen are found to be in close match, proposed alternate specimen offers a powerful tool for friction prediction in the absence of ring specimen. Some aspects of Exergy calculations have been in the past repeatedly used to quantify the quality and quantity of energy used in thermal energy processes. This attempt to drive a exergy utilization and compare for the first time two entirely different manufacturing processes, material processing by a mechanical method of straining of the material and thermal processing during cold forging of the same mass of the material using exergy formulation as metric. The exergy analysis of material processing is determined by performed work and utilized heat transfer using mechanical and thermal processes

  7. Embodied Energy and GHG Emissions from Material Use in Conventional and Unconventional Oil and Gas Operations.

    Science.gov (United States)

    Brandt, Adam R

    2015-11-01

    Environmental impacts embodied in oilfield capital equipment have not been thoroughly studied. In this paper, we present the first open-source model which computes the embodied energy and greenhouse gas (GHG) emissions associated with materials consumed in constructing oil and gas wells and associated infrastructure. The model includes well casing, wellbore cement, drilling mud, processing equipment, gas compression, and transport infrastructure. Default case results show that consumption of materials in constructing oilfield equipment consumes ∼0.014 MJ of primary energy per MJ of oil produced, and results in ∼1.3 gCO2-eq GHG emissions per MJ (lower heating value) of crude oil produced, an increase of 15% relative to upstream emissions assessed in earlier OPGEE model versions, and an increase of 1-1.5% of full life cycle emissions. A case study of a hydraulically fractured well in the Bakken formation of North Dakota suggests lower energy intensity (0.011 MJ/MJ) and emissions intensity (1.03 gCO2-eq/MJ) due to the high productivity of hydraulically fractured wells. Results are sensitive to per-well productivity, the complexity of wellbore casing design, and the energy and emissions intensity per kg of material consumed.

  8. Molting Materials: Restoring Superhydrophobicity after Severe Damage via Snakeskin-like Shedding.

    Science.gov (United States)

    Hönes, Roland; Kondrashov, Vitaliy; Rühe, Jürgen

    2017-05-16

    The nanostructures that are required to generate superhydrophobic surfaces are always sensitive to shear and are easily damaged, especially by scratching with sharp objects. As a result of this destruction, the water repellency will be lost. We introduce a novel approach to restoring the original surface properties after mechanical damage. In this approach, the damaged layer is shed like the skin of a snake. This is demonstrated with a three-layer stack as a proof-of-principle system: when the original, superhydrophobic surface layer is damaged, this leads to the dissolution of a sacrificial layer below it. Thus, the damaged layer is shed, a new unscathed surface is uncovered, and superhydrophobicity can easily be restored after a short washing.

  9. Embodied Energy Assessment and Comparisons for a Residential Building Using Conventional and Alternative Materials in Indian Context

    Science.gov (United States)

    Naveen Kishore, K.; Chouhan, J. S.

    2014-06-01

    Building sector is responsible for 40 % of the primary energy use and 24 % of carbon dioxide emissions in India. The main source of green house gas emissions from buildings is due to energy consumption. This paper aims to assess the embodied energy index and environmental impact of a two storied residential building. The study proposes various alternative materials which can be used in day to day construction in order to mitigate the environmental impact and climate change due to construction activity in India. Two types of construction techniques have been considered for the study, namely load bearing and reinforced concrete framed construction. Embodied energy and carbon dioxide emissions of walling and roofing components using conventional and alternative materials has also been analyzed and compared. The comparison is done based on two parameters namely, embodied energy/m2 and CO2 emissions per unit of floor area. The study shows that bricks, cement and steel are the three major contributors to the energy cost of constructing a building by conventional methods. A conventional two storied load bearing structure is 22 % more energy efficient when compared to a reinforced concrete structure. It has also been observed from the study that use of alternative material in the building envelope gives embodied energy savings between 50 and 60 % for a two storey load bearing structure and 30-42 % for a two storey reinforced concrete structure. Hence a load bearing construction is certainly a better alternative to RC framed construction for up to two storied structures in terms of embodied energy and environmental impacts.

  10. Development of non-conventional instrument transformers (NCIT) using smart materials

    Science.gov (United States)

    Nikolić, Bojan; Khan, Sanowar; Gabdullin, Nikita

    2016-11-01

    In this paper is presented a novel approach for current measurement using smart materials, magnetic shape memory (MSM) alloys. Their shape change can be controlled by the application of magnetic field or mechanical stress. This gives the possibility to measure currents by correlating the magnetic field produced by the current, shape change in an MSM- based sensor and the voltage output of a Linear Variable Differential Transducer (LVDT) actuated by this shape change. In the first part of the paper is presented a review of existing current measurement sensors by comparing their properties and highlighting their advantages and disadvantages.

  11. Effect of various endodontic irrigants on the push-out bond strength of biodentine and conventional root perforation repair materials.

    Science.gov (United States)

    Guneser, Mehmet Burak; Akbulut, Makbule Bilge; Eldeniz, Ayce Unverdi

    2013-03-01

    The aim of this study was to evaluate the effect of various endodontic irrigants on the push-out bond strength of Biodentine (Septodont, Saint Maur des Fossés, France) in comparison with contemporary root perforation repair materials. Midroot dentin of canine teeth was horizontally sectioned into 1-mm-thick slices. The canal space of each dentin slice was enlarged with a diamond bur to 1.4 mm in diameter. The samples were divided into 5 groups (n = 40), and the following materials were placed, respectively: Biodentine, ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK), amalgam, Dyract AP (Dentsply DeTrey, Konstanz, Germany), and intermediate restorative material (IRM, Dentsply DeTrey). The samples were wrapped in wet gauze for 10 minutes and divided into 3 subgroups (n = 10) to be immersed into 3.5% sodium hypochlorite, 2% chlorhexidine gluconate (CHX), or saline for 30 minutes. No irrigation was performed in the controls (n = 10), and a wet cotton pellet was placed over each test material. After incubation for 48 hours, the dislodgement resistance of the samples was measured using a universal testing machine. The samples were examined under a stereomicroscope to determine the nature of the bond failures. Biodentine showed significantly higher push-out bond strength than MTA (P amalgam ≥ IRM ≥ Biodentine > MTA. The push-out bond strength of Dyract AP, amalgam, IRM, and Biodentine was not significantly different when immersed in NaOCl, CHX, and saline solutions, whereas MTA lost strength when exposed to CHX. Biodentine showed considerable performance as a perforation repair material even after being exposed to various endodontic irrigants, whereas MTA had the lowest push-out bond strength to root dentin. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. All-ceramic single-tooth restorations: choosing the material to match the preparation--preparing the tooth to match the material.

    Science.gov (United States)

    Baltzer, A

    2008-01-01

    The shape of a crown preparation is the prime determinant for the choice of material for an all-ceramic restoration. One essential factor is the available space for the restoration, which requires a certain occlusal thickness. The dentist's preparation design determines the available vertical clearance, and the dental technician has the responsibility of advising the dentist with regard to either choosing the right material to match the preparation or to preparing the tooth to match the material. Assuming a minimum static fracture strength of > 2000 N, the following materials can be used for all-ceramic crowns: Laboratory surveys have shown that in most situations, the available occlusal clearance in clinical reality is only 0.8 to 0.9 mm (after cementing). This shows that the available space will often be insufficient for providing monoblock crowns and still on the tight side for veneered oxide ceramics (In Ceram, zirconia, etc.). However, crowns made of veneered oxide ceramics are much more complex to fabricate and much more expensive. By simply providing a minimal occlusal thickness of 1.5 mm, the treatment provider could therefore easily facilitate the use of the much more economical monoblock crowns without compromising either esthetics or strength. Actually, crowns with veneered oxide ceramic copings do not offer any higher fracture resistance compared to Mark II crowns as long as the minimum thickness requirements are met. The flexural strength of CAD/CAM-fabricated lithium disilicate rods is about twice that of CAD/CAM-fabricated Mark II rods. When used for crowns with a wall thickness of 1.5 mm, however, both materials exhibit the same fracture strength of between 2000 and 2500 N. This is related to the different reinforcing action of the adhesive luting agent, which is essentially required for both these materials. When choosing a material, preparation shapes, technical complexity and cost should be thoroughly compared and scrutinized and should figure

  13. Effects of Different Pediatric Drugs on the Color Stability of Various Restorative Materials Applicable in Pediatric Dentistry.

    Science.gov (United States)

    Tüzüner, Tamer; Turgut, Sedanur; Baygin, Ozgul; Yilmaz, Nagehan; Tuna, Elif Bahar; Ozen, Bugra

    2017-01-01

    Background. The chronic recommendation of pediatric drugs could exhibit erosive and cariogenic problems. Objective. To evaluate the effects of different pediatric drugs on the color stability of various restorative materials. Methods. Five specimens (1 mm × 3 mm) were prepared and immersed in ten different pediatric drugs and agitated every 8 hours daily for 2 min up to 1 week. Between immersion periods, the samples were stored in artificial saliva. After 1-week period, ΔE(⁎) values were calculated. Two-way ANOVA and Fisher's LSD test were used for statistical analysis at a level of p pediatric dentistry.

  14. Influence of flowable materials on microleakage of nanofilled and hybrid Class II composite restorations with LED and QTH LCUs

    Directory of Open Access Journals (Sweden)

    Sadeghi Mostafa

    2009-01-01

    Full Text Available Background: Class II composite restorations are more frequently being placed with margins apical to the cementoenamel junction (CEJ and margins within the dentin are prone to microleakage. Aims: This in vitro study was used to evaluate the influence of flowable composite and flowable compomer as gingival liner on microleakage in Class II composite restorations and compare a light-emitting diode (LED unit with a quartz tungsten halogen (QTH unit for light-activating composite resins. Materials and Methods: Mesioocclusal and distoocclusal Class II cavity preparations were made in 72 sound extracted premolars. The buccolingual width was 2.5 mm and the gingival margins of all the cavities were placed 1.0 mm apical to the CEJ. The boxes were prepared 1.5 mm deep axially, making 144 slot cavities. Teeth were randomly divided into the following two groups (n = 72: (I Universal Filtek Supreme XT; Universal Filtek Supreme XT + Flwable Filtek XT and Universal Filtek Supreme XT + Dyract Flow and (II Filtek Z250; Filtek Z250 + Flwable Filtek XT and Filtek Z250 + Dyract Flow. Flowable materials were injected into the gingival floor of the cavity to a thickness of 1.0 mm. Each increment was cured for 20 s. One-half of the subgroups in each group were cured with QTH and the other half with LED light curing units (LCUs. After 1 week of incubation at 37°C, the specimens were thermocycled (5-55°C, x1500, immersed in 0.5% basic fuchsine dye for 24 h and sectioned and microleakage was evaluated at the gingival margin by two examiners using a 0-3 score scale. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. Results: The groups utilizing flowable liners had significantly less microleakage (P < 0.05. No significant difference was identified between Universal Filtek Supreme XT and Filtek Z250 composites with and without flowable materials. There was no significant between utilizing flowable composite or flowable compomer and between each

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

    Science.gov (United States)

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

    2014-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-01

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

  17. Comparing material wastage levels between conventional in-situ and prefabrication construction in Hong Kong

    Institute of Scientific and Technical Information of China (English)

    Vivian W Y Tam; C M Tam; L Y Shen

    2004-01-01

    Generation of construction wastes constitutes a major impact to the environment. Studies have beend directed toward reducing wastes of the various construction processes. However, contractors in Hong Kong are rather conservative and lack motivation to develop new technology for waste minimization. This paper examines the benefits of using prefabrication in reducing material wastage levels for some traditional in-situ trades such as concreting, rebar fixing, bricklaying, drywall, plastering, screeding and tiling in Hong Kong. By measuring thirty construction projects, it is been found that waste levels of all major construction trades can be effectively reduced. This is particularly significant in the trade of plastering where 100% saving can be achieved after adopting prefabrication. The standardized design of the building can also be useful in the adoption of prefabrication for private housing projects.

  18. Effects of the Nd:YAG laser on amalgam dental restorative material: a preliminary study

    Science.gov (United States)

    Cernavin, Igor; Hogan, Sean P.

    1996-09-01

    The Nd:YAG laser has been marketed as an instrument for use on both hard and soft dental tissues. Its potential for use on hard tissues is limited but it may be the instrument of choice for use in certain soft tissue procedures. The aim of this study was to examine the effects of the Nd:YAG laser on amalgam restorations which frequently occur on tooth surfaces adjacent to areas of soft tissue which may be subjected to the laser. The amalgam used was Tytin. The laser firing was controlled by a computer and a constant repetition rate of 40 Hz was used. Energy per pulse was altered as follows, 30 mJ, 40 mJ, 60 mJ, 80 mJ, 120 mJ and 140 mJ. Exposure times of 0.05 sec, 0.125 sec, 0.25 sec, 0.5 sec, 1 sec, 2 sec, 3 sec, 4 sec, and 5 sec were used. The width of defect was measured using a Nikon measurescope with 10x magnification and it was established that the damage threshold lies between 0.125 sec and 0.25 sec for 30 mJ per pulse. The data was analyzed using a one way ANOVA statistical test. There was a significant correlation between the width of the defect and energy per pulse setting as well as exposure time. The findings indicate that amalgam restorations are prone to damage from inadvertent laser exposure and clinicians must take measures to protect such restorations during lasing of soft tissues.

  19. Evaluation of the penetration of restoration materials in stone. A new method

    OpenAIRE

    Rodríguez-Gordillo, J.; Durán-Suárez, J. A.; García-Casco, A.

    2000-01-01

    We have used the measurements of the water-stone contact angle on the surface of sections of biocalcarenite samples to evaluate the penetration of organic and silico-organic restoration products in this rock. The method has been found to be effective and precise, allowing us to distinguish the depth of the zone with water-repellent characteristics from that with merely a consolidating effect.

    Se utilizan las medidas del ángulo de contacto agua-piedra sobre la superficie de ...

  20. Fluoride release of glass ionomer restorations after bleaching with two different bleaching materials

    OpenAIRE

    Baroudi, Kusai; Mahmoud, Rasha Said; Tarakji, Bassel

    2013-01-01

    Objective: This study was designed to evaluate the effect of two bleaching agents on the fluoride release of three types of glass ionomer materials. Materials and Methods: A total of 90 specimens of the tested materials (Ketac Fil, Photac Fil and F2000) were prepared by a split Teflon ring with an internal diameter of 5 mm and thickness of 2 mm. The tested materials were applied and bleached according to manufacturer instructions. Fluoride release measurements were made by using specific ion ...

  1. Evaluation of nystatin containing chitosan hydrogels as potential dual action bio-active restorative materials: in vitro approach.

    Science.gov (United States)

    Perchyonok, V Tamara; Reher, Vanessa; Zhang, Shengmiao; Basson, Nicki; Grobler, Sias

    2014-11-28

    Healing is a specific biological process related to the general phenomenon of growth and tissue regeneration and is a process generally affected by several systemic conditions or as detrimental side-effects of chemotherapy- and radiotherapy-induced inflammation of the oral mucosa. The objectives of this study is to evaluate the novel chitosan based functional drug delivery systems, which can be successfully incorporated into "dual action bioactive restorative materials", capable of inducing in vitro improved wound healing prototype and containing an antibiotic, such as nystatin, krill oil as an antioxidant and hydroxyapatite as a molecular bone scaffold, which is naturally present in bone and is reported to be successfully used in promoting bone integration when implanted as well as promoting healing. The hydrogels were prepared using a protocol as previously reported by us. The physico-chemical features, including surface morphology (SEM), release behaviors, stability of the therapeutic agent-antioxidant-chitosan, were measured and compared to the earlier reported chitosan-antioxidant containing hydrogels. Structural investigations of the reactive surface of the hydrogel are reported. Release of nystatin was investigated for all newly prepared hydrogels. Bio-adhesive studies were performed in order to assess the suitability of these designer materials. Free radical defense capacity of the biomaterials was evaluated using established in vitro model. The bio-adhesive capacity of the materials in the in vitro system was tested and quantified. It was found that the favorable synergistic effect of free radical built-in defense mechanism of the new functional materials increased sustainable bio-adhesion and therefore acted as a functional multi-dimensional restorative material with potential application in wound healing in vitro.

  2. Characterization of Electronic Materials HgZnSe and HgZnTe Using Innovative and Conventional Techniques

    Science.gov (United States)

    Tanton, George; Kesmodel, Roy; Burden, Judy; Su, Ching-Hua; Cobb, Sharon D.; Lehoczky, S. L.

    2000-01-01

    HgZnSe and HgZnTe are electronic materials of interest for potential IR detector and focal plane array applications due to their improved strength and compositional stability over HgCdTe, but they are difficult to grow on Earth and to fully characterize. Conventional contact methods of characterization, such as Hall and van der Paw, although adequate for many situations are typically labor intensive and not entirely suitable where only very small samples are available. To adequately characterize and compare properties of electronic materials grown in low earth orbit with those grown on Earth, innovative techniques are needed that complement existing methods. This paper describes the implementation and test results of a unique non-contact method of characterizing uniformity, mobility, and carrier concentration together with results from conventional methods applied to HgZnSe and HgZnTe. The innovative method has advantages over conventional contact methods since it circumvents problems of possible contamination from alloying electrical contacts to a sample and also has the capability to map a sample. Non- destructive mapping, the determination of the carrier concentration and mobility at each place on a sample, provides a means to quantitatively compare, at high spatial resolution, effects of microgravity on electronic properties and uniformity of electronic materials grown in low-Earth orbit with Earth grown materials. The mapping technique described here uses a 1mm diameter polarized beam of radiation to probe the sample. Activation of a magnetic field, in which the sample is placed, causes the plane of polarization of the probe beam to rotate. This Faraday rotation is a function of the free carrier concentration and the band parameters of the material. Maps of carrier concentration, mobility, and transmission generated from measurements of the Faraday rotation angles over the temperature range from 300K to 77K will be presented. New information on band parameters

  3. Evaluation of the theoretical and clinical methods for reducing marginal leakage in resin-based composite restorative materials: A review

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Keshvad

    2016-11-01

    Full Text Available Resin-based composite restorative materials  have a substantial share in dental treatments. Their esthetic has made them patients’ first choice as restorative materials. Marginal leakage is one of their problems which leads to recurrent caries and post-operative hypersensitivity. Our aim was to evaluate the theoretical and clinical methods that have been proposed in the dental literature. Around 50 articles from Pubmed, SCOPUS and google scholar were selected and categorized in 4 groups based on the selected keywords. All the studies discussed in this paper have emphasized that there is no way to eliminate the microleakage but it can be reduced by means of some approaches. On the other hand, due to the multifactorial nature and difference of oral environment and laboratory conditions, there isn’t any certain way to define precisely. It seems that there is an absolute need for more research in this field to make the relation of theoretical results and clinical findings possible.

  4. Effects of Different Pediatric Drugs on the Color Stability of Various Restorative Materials Applicable in Pediatric Dentistry

    Science.gov (United States)

    Turgut, Sedanur; Baygin, Ozgul; Ozen, Bugra

    2017-01-01

    Background. The chronic recommendation of pediatric drugs could exhibit erosive and cariogenic problems. Objective. To evaluate the effects of different pediatric drugs on the color stability of various restorative materials. Methods. Five specimens (1 mm × 3 mm) were prepared and immersed in ten different pediatric drugs and agitated every 8 hours daily for 2 min up to 1 week. Between immersion periods, the samples were stored in artificial saliva. After 1-week period, ΔE⁎ values were calculated. Two-way ANOVA and Fisher's LSD test were used for statistical analysis at a level of p glass ionomer (2.08 ± 0.40) pairwise. The most prominent ΔE⁎ value elevations were obtained in composite material compared to the compomer and/or glass ionomers in Macrol, Ferrosanol B, and Ventolin (p glass ionomers in pediatric dentistry. PMID:28164130

  5. Evaluation of conventional and digital radiography capacities for distinguishing dental materials on radiograms depending on the present radiopacifying agent

    Directory of Open Access Journals (Sweden)

    Antonijević Đorđe

    2014-01-01

    Full Text Available Bacgroun/Aim. The radiopacity of an endodontic material can considerably vary as measured on film and a digital sensor. Digital radiography offers numerous advantages over convential film-based radiography in dental clinical practice regarding both diagnostic capabilities and postintervention procedures. The aim of this study was to investigate the capacity of conventional and charge-conpled device (CCD based digital radiography to detect material on radiograph depending on the radio-pacifying agent present in the material. Methods. Experimental cements were formulated by mixing Portland cement with the following radiopacifying agents: zinc oxide (ZnO, zirconium oxide (ZrO2, titanium dioxide (TiO2, barium sulphate (BaSO4, iodoform (CHI3, bismuth oxide (Bi2O3 and ytterbium trifluoride (YbF3. In addition, 5 endodontic materials comprising Endomethasone®, Diaket®, N2®, Roth 801® and Acroseal® were investigated to serve as control. Per three specimens of each material were radiographed alongside an aluminum step wedge on film (Eastman Kodak Company®, Rochester, NY and a CCD-based digital sensor (Trophy Radiologie®, Cedex, France. Radiopacity values were calculated by converting the radiographic densities of the specimens expressed as a mean optical densities or mean grey scale values into equivalent thickness of aluminum. Results. Twoway ANOVA detected no significant differences with respect to the imaging system (p > 0.05, but the differences were significant with respect to radiopacifier (p < 0.001 and the interaction of the two factors (p < 0.05. Paired ttest revealed significant differences between the methods used for pure Portland cement, all concentrations of BaSO4 and CHI3, 10% and 20% additions of ZrO2 and Bi2O3 and 10% and 30% addition of YbF3 (p < 0.05. Conclusion. The materials which incorporate CHI3 or BaSO4 as radiopacifying agents are expected to be significantly more radiopaque on a digital sensor than on film. During clinical

  6. Polishability and wear resistance of splint material for oral appliances produced with conventional, subtractive, and additive manufacturing.

    Science.gov (United States)

    Huettig, Fabian; Kustermann, Achim; Kuscu, Ebru; Geis-Gerstorfer, Jürgen; Spintzyk, Sebastian

    2017-07-14

    Occlusal splints to treat bruxism are commonly made from polymethylmethacrylate (PMMA) in a manual workflow (powder-liquid technique). Today digitalization allows a machine-based manufacturing in subtractive (milling) and additive (printing) means using industrial-made PMMA or comparable resins. An in-vitro study should assess the surface finish and screen the wear resistance of conventional and industrial materials. Therefore, a total of 30 specimens made from conventionally PMMA (group C; powder-liquid, Palapress), polycarbonate ingots (group S; innoBlanc splint plus), and light-curing resin (group A; VarseoWax splint) were polished to examine the surface roughness (Ra) by profilometry and further analyzed by SEM. The specimens were loaded with a steatite ball moving 5000 times along 1cm with 5N of surface pressure under constant wetting (artificial saliva). The total height of profile (Pt) was calculated by further profilometry of the specimens. All specimen showed initially comparable Ra values ranging between 0.06 and 0.05µm (SD = 0.01) after polishing. SEM investigations revealed no visual cues for scratches or irregularities in any group. After abrasion test, the comparison of the wear depths, revealed mean Pt values of 111.4µm (SD = 18.5) in C, 85.7µm (SD = 21.5) in S, and 99.1µm (SD = 21.5) in A, whereas the mean of S was statistically different from C (p = 0.025). No signs of abrasion were found on the steatite balls. All materials showed comparable polished surfaces and a similar scale of wear. It remains questionable if the detected statistical differences are of clinical relevance, but indicates the need for tests of novel materials, especially in additive manufacturing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Materials and technologies in Art Nouveau architecture: Facade decoration cases in Italy, Portugal and Poland for a consistent restoration

    Directory of Open Access Journals (Sweden)

    Sandrolini, F.

    2011-12-01

    Full Text Available The results of a diagnostic survey on the materials of representative Art Nouveau buildings in Italy, Portugal and Poland are here presented and compared, as a contribution to their understanding and, hence, to support compatible restoration. In particular, the facade decorations were investigated for the appraisal of their materials and technologies, often neglected in current maintenance/restoration works and so cancelled, leading to a severe loss in architectural image. The ongoing diagnostic campaign, in collaboration among different universities, is aimed to set up a database on materials and technologies of Art Nouveau facade decorations at a European scale, as a technical-scientific background for the highlighting of preservation guidelines.

    En este trabajo se presentan los resultados de un estudio de diagnóstico sobre materiales representativos de edificios del periodo del Modernismo en Italia, Portugal y Polonia. Con la comparación de estos resultados se pretende contribuir a incrementar el conocimiento de los materiales usados en este patrimonio, que permita realizar más eficazmente las futuras intervenciones de restauración. En particular, se analizan las decoraciones de las fachadas, pasando por el reconocimiento de sus materiales constituyentes y de las tecnologías usadas, que muchas veces no son adecuadamente estudiados en intervenciones de mantenimiento y/o restauración, provocando graves pérdidas en su imagen y lenguaje arquitectónico original. Con la campaña de trabajos de diagnóstico, en colaboración con varias universidades, se pretende crear una base de datos sobre materiales y tecnologías usados en las decoraciones de fachada en el periodo del Modernismo a una escala europea. El material podrá constituirse en una herramienta técnico-científica de soporte al desarrollo de directrices y recomendaciones para la preservación de este patrimonio.

  8. Matching seed to site by climate similarity: techniques to prioritize plant materials development and use in restoration

    Science.gov (United States)

    Doherty, Kyle; Butterfield, Bradley J.; Wood, Troy E.

    2017-01-01

    Land management agencies are increasing the use of native plant materials for vegetation treatments to restore ecosystem function and maintain natural ecological integrity. This shift toward the use of natives has highlighted a need to increase the diversity of materials available. A key problem is agreeing on how many, and which, new accessions should be developed. Here we describe new methods that address this problem. Our methods use climate data to calculate a climate similarity index between two points in a defined extent. This index can be used to predict relative performance of available accessions at a target site. In addition, the index can be used in combination with standard cluster analysis algorithms to quantify and maximize climate coverage (mean climate similarity), given a modeled range extent and a specified number of accessions. We demonstrate the utility of this latter feature by applying it to the extents of 11 western North American species with proven or potential use in restoration. First, a species-specific seed transfer map can be readily generated for a species by predicting performance for accessions currently available; this map can be readily updated to accommodate new accessions. Next, the increase in climate coverage achieved by adding successive accessions can be explored, yielding information that managers can use to balance ecological and economic considerations in determining how many accessions to develop. This approach identifies sampling sites, referred to as climate centers, which contribute unique, complementary, climate coverage to accessions on hand, thus providing explicit sampling guidance for both germplasm preservation and research. We examine how these and other features of our approach add to existing methods used to guide plant materials development and use. Finally, we discuss how these new methods provide a framework that could be used to coordinate native plant materials development, evaluation, and use across

  9. Evaluation of Nystatin Containing Chitosan Hydrogels as Potential Dual Action Bio-Active Restorative Materials: in Vitro Approach

    Directory of Open Access Journals (Sweden)

    V. Tamara Perchyonok

    2014-11-01

    Full Text Available Healing is a specific biological process related to the general phenomenon of growth and tissue regeneration and is a process generally affected by several systemic conditions or as detrimental side-effects of chemotherapy- and radiotherapy-induced inflammation of the oral mucosa. The objectives of this study is to evaluate the novel chitosan based functional drug delivery systems, which can be successfully incorporated into “dual action bioactive restorative materials”, capable of inducing in vitro improved wound healing prototype and containing an antibiotic, such as nystatin, krill oil as an antioxidant and hydroxyapatite as a molecular bone scaffold, which is naturally present in bone and is reported to be successfully used in promoting bone integration when implanted as well as promoting healing. The hydrogels were prepared using a protocol as previously reported by us. The physico-chemical features, including surface morphology (SEM, release behaviors, stability of the therapeutic agent-antioxidant-chitosan, were measured and compared to the earlier reported chitosan-antioxidant containing hydrogels. Structural investigations of the reactive surface of the hydrogel are reported. Release of nystatin was investigated for all newly prepared hydrogels. Bio-adhesive studies were performed in order to assess the suitability of these designer materials. Free radical defense capacity of the biomaterials was evaluated using established in vitro model. The bio-adhesive capacity of the materials in the in vitro system was tested and quantified. It was found that the favorable synergistic effect of free radical built-in defense mechanism of the new functional materials increased sustainable bio-adhesion and therefore acted as a functional multi-dimensional restorative material with potential application in wound healing in vitro.

  10. Evaluation of the penetration of restoration materials in stone. A new method

    Directory of Open Access Journals (Sweden)

    Rodríguez-Gordillo, J.

    2000-12-01

    Full Text Available We have used the measurements of the water-stone contact angle on the surface of sections of biocalcarenite samples to evaluate the penetration of organic and silico-organic restoration products in this rock. The method has been found to be effective and precise, allowing us to distinguish the depth of the zone with water-repellent characteristics from that with merely a consolidating effect.

    Se utilizan las medidas del ángulo de contacto agua-piedra sobre la superficie de secciones de probetas de biocalcarenita, para evaluar la penetrabilidad de productos de restauración orgánicos y silicoorgánicos en esta roca. El método se revela como eficaz y preciso, permitiendo discriminar la profundidad de la zona con características hidrófugas de aquélla exclusivamente consolidada.

  11. A comparison of the sealing ability of various temporary restorative materials to seal the access cavity: An in vitro study

    Directory of Open Access Journals (Sweden)

    Aji Markose

    2016-01-01

    Full Text Available Introduction: In multiple-appointment root canal treatment, a temporary filling material is used to seal the access cavity between visits. The primary function of this material is to prevent the contamination of the root canal system by fluids, organic debris, and bacteria from the oral cavity. Material and Methods: A total of fifty extracted noncarious unrestored human maxillaryanterior teeth with intact crowns and roots were selected The canals were instrumented using stepback technique and sodium hypochlorite (3% and hydrogen peroxide (3% were used as irrigants for each specimen alternatively. The coronal two-thirds of each canal were flared using Gates-Glidden drills up to no. 3 size and obturated with Gutta-percha using zinc oxide-eugenol (ZnOE as sealer. The teeth were then randomly selected and divided into six groups out of which four were experimental groups and two control groups. The teeth were then immersed in 2% methylene blue dye solution for 3 days. All sealing materials and Gutta-percha were gently removed from the walls of the canal, and the entire circumference of the canal wall examined for dye penetration. Results: The lowest mean leakage was in the Fermit-N group followed by Cavit-W, ZnOE, intermediate restorative materials (IRM, and positive control. Conclusion: Fermit-N showed better sealing ability compared to cavit, ZnOE and IRM.

  12. Effect of nightguard vital bleaching gel on the color stability of provisional restorative materials

    Directory of Open Access Journals (Sweden)

    Salwa Omar Bajunaid

    2016-01-01

    Conclusions: Composite-based provisional material showed highest color stability when exposed to vital tooth bleaching gel, whereas methacrylate-based material was the least color stable. Polycarbonate crowns were more color stable when exposed to 15% bleaching gel as opposed to 10% bleaching gel.

  13. Fluoride release of glass ionomer restorations after bleaching with two different bleaching materials.

    Science.gov (United States)

    Baroudi, Kusai; Mahmoud, Rasha Said; Tarakji, Bassel

    2013-04-01

    This study was designed to evaluate the effect of two bleaching agents on the fluoride release of three types of glass ionomer materials. A total of 90 specimens of the tested materials (Ketac Fil, Photac Fil and F2000) were prepared by a split Teflon ring with an internal diameter of 5 mm and thickness of 2 mm. The tested materials were applied and bleached according to manufacturer instructions. Fluoride release measurements were made by using specific ion electrode. Results revealed that bleaching with opalescence Xtra caused little increase in fluoride release from Ketac Fil and Photac Fil but has no effect on F2000. However, Opalescence Quick had no significant effect on the three tested materials. Bleaching effect on fluoride release is material dependent and time has a significant role on fluoride release.

  14. Influence of Cavity Margin Design and Restorative Material on Marginal Quality and Seal of Extended Class II Resin Composite Restorations In Vitro.

    Science.gov (United States)

    Soliman, Sebastian; Preidl, Reinhard; Karl, Sabine; Hofmann, Norbert; Krastl, Gabriel; Klaiber, Bernd

    2016-01-01

    To investigate the influence of three cavity designs on the marginal seal of large Class II cavities restored with low-shrinkage resin composite limited to the enamel. One hundred twenty (120) intact human molars were randomly divided into 12 groups, with three different cavity designs: 1. undermined enamel, 2. box-shaped, and 3. proximal bevel. The teeth were restored with 1. an extra-low shrinkage (ELS) composite free of diluent monomers, 2. microhybrid composite (Herculite XRV), 3. nanohybrid composite (Filtek Supreme XTE), and 4. silorane-based composite (Filtek Silorane). After artificial aging by thermocycling and storage in physiological saline, epoxy resin replicas were prepared. To determine the integrity of the restorations' approximal margins, two methods were sequentially employed: 1. replicas were made of the 120 specimens and examined using SEM, and 2. the same 120 specimens were immersed in AgNO3 solution, and the dye penetration depth was observed with a light microscope. Statistical analysis was performed using the Kruskal-Wallis and the Dunn-Bonferroni tests. After bevel preparation, SEM observations showed that restorations did not exhibit a higher percentage of continuous margin (SEM-analysis; p>0.05), but more leakage was found than with the other cavity designs (pcomposite restorations and is no longer recommended. However, undermined enamel should be removed to prevent enamel fractures.

  15. Effect of storage in water and thermocycling on hardness and roughness of resin materials for temporary restorations

    Directory of Open Access Journals (Sweden)

    Jerusa Cleci de Oliveira

    2010-09-01

    Full Text Available PURPOSE: This study evaluated the effect of storage in water and thermocycling on hardness and roughness of resin materials for temporary restorations. MATERIAL AND METHODS: Three acrylic resins (Dencor-De, Duralay-Du, and Vipi Cor-VC were selected and one composite resin (Opallis-Op was used as a parameter for comparison. The materials were prepared according to the manufacturers' instructions and were placed in stainless steel moulds (20 mm in diameter and 5 mm thick. Thirty samples of each resin were made and divided into three groups (n = 10 according to the moment of Vickers hardness (VHN and roughness (Ra analyses: C (control group: immediately after specimen preparation; Sw: after storage in distilled water at 37 °C for 24 hours; Tc: after thermocycling (3000 cycles; 5-55 °C, 30 seconds dwell time. Data were submitted to 2-way ANOVA followed by Tukey's test (α = 0.05. RESULTS: Op resin had higher surface hardness values (p 0.05 in roughness among materials (De = 0.31 ± 0.07; Du = 0.51 ± 0.20; VC = 0.41 ± 0.15; Op = 0.42 ± 0.18. Storage in water did not change hardness and roughness of the tested materials (p > 0.05. There was a significant increase in roughness after thermocycling (p < 0.05, except for material Du, which showed no significant change in roughness in any evaluated period (p = 0.99. CONCLUSION: Thermocycling increased the roughness in most tested materials without affecting hardness, while storage in water had no significant effect in the evaluated properties.

  16. Discoloration of the mucosa caused by different restorative materials - a spectrophotometric in vitro study.

    Science.gov (United States)

    Ioannidis, Alexis; Cathomen, Elena; Jung, Ronald E; Fehmer, Vincent; Hüsler, Jürg; Thoma, Daniel S

    2017-09-01

    To evaluate the discoloration of the mucosa caused by different ceramic and metal-based materials. On six pig maxillae, trap-door flaps were prepared bilaterally. Different ceramic and metal-based specimens were placed underneath the flap. To simulate increasing mucosal thicknesses (MC), connective tissue grafts (CTGs) were harvested. Spectrophotometric measurements were performed prior to flap elevation (TBL ) and for each material under the flap alone (1 mm MC) (TMC1 ), with a 1-mm CTG (2-mm MC) (TMC2 ) and with a 2-mm CTG (3-mm MC) (TMC3 ). Tested materials were as follows: Zr1 (zirconia), Zr2 (zirconia + pink ceramic), Zr3 (zirconia), Zr4 (fluorescent zirconia), Zr5 (zirconia), Zr6 (high translucent zirconia), Zr7 (low translucent zirconia) and Zr8 (low translucent zirconia), Gol (gold alloy), Ti1 (titanium alloy), Ti2 (anodized gold-shaded titanium alloy) and Ti3 (anodized pink-shaded titanium alloy). Color differences (ΔE) were calculated comparing the measurement of the native tissue (TBL ) and the measurements with varying mucosal thicknesses (TMC1-3 ). For ceramic materials, the median ΔE values for the different time-point comparison ranged as follows: 3.80 (Zr4) - 7.47 (Zr2) (pooled); 3.15 (Zr4) - 8.13 (Zr2) (TBL -TMC1 ); 3.39 (Zr4) - 7.24 (Zr2) (TBL -TMC2 ); 4.31 (Zr8) - 6.99 (Zr2) (TBL -TMC3 ). For metal-based materials, the median ΔE values were as follows: 4.20 (Gol) - 5.82 (Ti3) (pooled); 3.21 (Gol) - 13.56 (Ti1) (TBL -TCM1 ); 4.0 (Ti1) - 5.27 (Gol) (TBL -TCM2 ); 3.11 (Ti1) - 5.11 (Gol) (TBL -TCM2 ). The comparison of the materials and the time points showed in the nonparametric linear mixed model a significant interaction effect between material and time point (P materials result in an evident discoloration of the mucosal tissue, tending to decrease with increasing mucosal thickness. The use of fluorescent zirconia (ceramic materials) or gold alloy (metal-based materials) lead to the least discoloration. © 2016 John Wiley & Sons A

  17. Optimizing the design of bio-inspired functionally graded material (FGM) layer in all-ceramic dental restorations.

    Science.gov (United States)

    Cui, Chang; Sun, Jian

    2014-01-01

    Due to elastic modulus mismatch between the different layers in all-ceramic dental restorations, high tensile stress concentrates at the interface between the ceramic core and cement. In natural tooth structure, stress concentration is reduced by the functionally graded structure of dentin-enamel junction (DEJ) which interconnects enamel and dentin. Inspired by DEJ, the aim of this study was to explore the optimum design of a bio-inspired functionally graded material (FGM) layer in all-ceramic dental restorations to achieve excellent stress reduction and distribution. Three-dimensional finite element model of a multi-layer structure was developed, which comprised bilayered ceramic, bio-inspired FGM layer, cement, and dentin. Finite element method and first-order optimization technique were used to realize the optimal bio-inspired FGM layer design. The bio-inspired FGM layer significantly reduced stress concentration at the interface between the crown and cement, and stresses were evenly distributed in FGM layer. With the optimal design, an elastic modulus distribution similar to that in DEJ occurred in the FGM layer.

  18. The role of the ionomer glass component in polyacid-modified composite resin dental restorative materials.

    Science.gov (United States)

    Adusei, Gabriel O; Deb, Sanjukta; Nicholson, John W

    2004-07-01

    In order to model the processes that occur within polyacid-modified composite resin ("compomer") dental restoratives, a series of experiments has been carried out with silanated and silane-free ionomer glass G338, and silanated and silane-free unreactive glass (Raysorb T-4000). In an acid-base reaction with dental grade aqueous maleic acid-acrylic acid copolymer solution, the setting time of the silanted G338 was found to be 9 min, compared with 5 min for the silane-free glass. Inclusion of each glass in an experimental composite resin system showed that the formulations which contained G338 absorbed more water than the formulations which contained Raysorb T-4000, regardless of whether or not the glass was silanted. Biaxial flexure strength was superior for experimental composites containing Raysorb T-4000, with highest results being obtained with the silanated glass. Overall these results demonstrate that silanation of the filler is essential for optimal physical properties but that, for the ionomer glass, it inhibits the acid-base reaction. The presence of ionomer glass led to an increase in water uptake compared with the unreactive glass, regardless of the presence of silane.

  19. Quality restoration of waste polyolefin plastic material through the dissolution-reprecipitation technique

    Directory of Open Access Journals (Sweden)

    Hadi Jasim Arkan

    2014-01-01

    Full Text Available This study examines the restoration of waste plastic polymers based on LDPE, HDPE or PP through dissolution/reprecipitation. Experimental conditions of the recycling process, including type of solvent/non-solvent, original polymer concentration and dissolution temperature were optimized. Results revealed that by using the different prepared solvents/non-solvents at various ratios and temperatures, the polymer recovery was always greater than 94%. The FTIR spectra and the thermal properties (melting point and crystallinity of the polymers before and after recycling were measured using Differential Scanning Calorimetry (DSC. Mechanical properties of the waste polymer before and after recycling were also measured. Besides small occasional deviations, the properties did not change. The tensile strength at maximum load was 7.1, 18.8, and 7.4 MPa for the recycled LDPE, HDPE and PP, respectively and 7.78, 18.54 and 7.86 MPa for the virgin polymer. For the waste, the strength was 6.2, 15.58 and 6.76 MPa.

  20. A fluoride release-adsorption-release system applied to fluoride-releasing restorative materials.

    Science.gov (United States)

    Suljak, J P; Hatibovic-Kofman, S

    1996-09-01

    This investigation compared the initial fluoride release and release following refluoridation of three resin-modified glass-ionomer cements (Photac-Fil Applicap, Vitremer, and Fuji II LC) and a new polyacid-modified resin composite material (Dyract). After daily flouride release was measured for 8 days, specimens were refluoridated in 1,000-ppm solutions of fluoride ion for 10 minutes and fluoride release was measured for 5 days. Two further 5-day refluoridation-release periods were carried out. All materials released fluoride initially. Photac released the most; Dyract released the least. Initial release was greatest over the first few days. All materials released significantly more fluoride for 24 to 48 hours after refluoridation. Less fluoride was released with each successive refluoridation for the three glass-ionomer cements. The release from the Dyract compomer remained at a comparatively constant and significantly lower level following each refluoridation.

  1. Novel nano-particles as fillers for an experimental resin-based restorative material.

    Science.gov (United States)

    Rüttermann, S; Wandrey, C; Raab, W H-M; Janda, R

    2008-11-01

    The purpose of this study is to compare the properties of two experimental materials, nano-material (Nano) and Microhybrid, and two trade products, Clearfil AP-X and Filtek Supreme XT. The flexural strength and modulus after 24h water storage and 5000 thermocycles, water sorption, solubility and X-ray opacity were determined according to ISO 4049. The volumetric behavior (DeltaV) after curing and after water storage was investigated with the Archimedes principle. ANOVA was calculated with p<0.05. Clearfil AP-X showed the highest flexural strength (154+/-14 MPa) and flexural modulus (11,600+/-550 MPa) prior to and after thermocycling (117+/-14 MPa and 13,000+/-300 MPa). The flexural strength of all materials decreased after thermocycling, but the flexural modulus decreased only for Filtek Supreme XT. After thermocycling, there were no significant differences in flexural strength and modulus between Filtek Supreme XT, Microhybrid and Nano. Clearfil AP-X had the lowest water sorption (22+/-1.1 microg mm(-3)) and Nano had the highest water sorption (82+/-2.6 microg mm(-3)) and solubility (27+/-2.9 microg mm(-3)) of all the materials. No significant differences occurred between the solubility of Clearfil AP-X, Filtek Supreme XT and Microhybrid. Microhybrid and Nano provided the highest X-ray opacity. Owing to the lower filler content, Nano showed higher shrinkage than the commercial materials. Nano had the highest expansion after water storage. After thermocycling, Nano performed as well as Filtek Supreme XT for flexural strength, even better for X-ray opacity but significantly worse for flexural modulus, water sorption and solubility. The performances of microhybrids were superior to those of the nano-materials.

  2. 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

  3. A resin composite material containing an eugenol derivative for intracanal post cementation and core build-up restoration.

    Science.gov (United States)

    Almaroof, A; Rojo, L; Mannocci, F; Deb, S

    2016-02-01

    To formulate and evaluate new dual cured resin composite based on the inclusion of eugenyl methacrylate monomer (EgMA) with Bis-GMA/TEGDMA resin systems for intracanal post cementation and core build-up restoration of endodontically treated teeth. EgMA was synthesized and incorporated at 5% (BTEg5) or 10% (BTEg10) into dual-cure formulations. Curing properties, viscosity, Tg, radiopacity, static and dynamic mechanical properties of the composites were determined and compared with Clearfil™DC Core-Plus, a commercial dual-cure, two-component composite. Statistical analysis of the data was performed with ANOVA and the Tukey's post-hoc test. The experimental composites were successfully prepared, which exhibited excellent curing depths of 4.9, 4.7 and 4.2 mm for BTEg0, BTEg5 and BTEg10 respectively, which were significantly higher than Clearfil™DC. However, the inclusion of EgMA initially led to a lower degree of cure, which increased when measured at 24 h with values comparable to formulations without EgMA, indicating post-curing. The inclusion of EgMA also lowered the polymerization exotherm thereby reducing the potential of thermal damage to host tissue. Both thermal and viscoelastic analyses confirmed the ability of the monomer to reduce the stiffness of the composites by forming a branched network. The compressive strength of BTEg5 was significantly higher than the control whilst flexural strength increased significantly from 95.9 to 114.8 MPa (BTEg5) and 121.9 MPa (BTEg10). Radiopacity of the composites was equivalent to ∼3 mm Al allowing efficient diagnosis. The incorporation of EgMA within polymerizable formulations provides a novel approach to prepare reinforced resin composite material for intracanal post cementation and core build-up and the potential to impart antibacterial properties of eugenol to endodontic restorations. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  4. Synthesis and characterizations of a fluoride-releasing dental restorative material.

    Science.gov (United States)

    Khan, Abdul Samad; Aamer, Sidra; Chaudhry, Aqif Anwar; Wong, Ferranti S L; Ur Rehman, Ihtesham

    2013-08-01

    The aim was to develop an obturating material which has the tendency to release fluoride and minimize interfaces with tooth. Nano-fluorapatite (nFA) powder was synthesized by sol-gel. The composite based on polyurethane (PU) was obtained by chemically binding the nFA (10, 15, 20%wt/wt) to the diisocyanate component by utilizing in-situ polymerization. The procedure involved stepwise addition of monomeric units of PU, and optimizing the reagent concentrations to synthesize composite. The structural, phase and morphological analysis of nFA was evaluated. The structural, fluoride release and in-vitro adhesion analysis with tooth structure of PU/nFA was conducted. For fluoride release analysis the samples were stored in artificial saliva and deionized water for periodical time intervals. Bond strength of composites was analyzed by push-out test. Chemical linkage was achieved between PU and nFA without intermediate coupling agent. The insignificant difference of fluoride release pattern was observed in artificial saliva and (p≥0.05) deionized water. The PU/nFA composite provided sustained release of fluoride over a long period of time. The composite showed more adhesion toward tooth structure with the increase in concentration of nFA. Bond strength of composite was in accordance with root canal filling material, hence, the material with anti-cariogenic properties can be used as an obturating material.

  5. Comparative evaluation of microleakage in Class II restorations using open vs. closed centripetal build-up techniques with different lining materials

    Directory of Open Access Journals (Sweden)

    Shefali Sawani

    2014-01-01

    Full Text Available Background: Evaluation of microleakage is important for assessing the success of new restorative materials and methods. Aim and Objectives: Comparative evaluation of microleakage in Class II restorations using open vs. closed centripetal build-up techniques with different lining materials. Materials and Methods: Standardized mesi-occlusal (MO and distoocclusal (DO Class II tooth preparations were preparedon 53 molars and samples were randomly divided into six experimental groups and one control group for restorations. Group 1: Open-Sandwich technique (OST with flowable composite at the gingival seat. Group 2: OST with resin-modified glass ionomer cement (RMGIC at the gingival seat. Group 3: Closed-Sandwich technique (CST with flowable composite at the pulpal floor and axial wall. Group 4: CST with RMGIC at the pulpal floor and axial wall. Group 5: OST with flowable composite at the pulpal floor, axial wall, and gingival seat. Group 6: OST with RMGIC at the pulpal floor, axial wall, and gingival seat. Group 7: Control - no lining material, centripetal technique only. After restorations and thermocycling, apices were sealed and samples were immersed in 0.5% basic fuchsin dye. Sectioning was followed by stereomicroscopic evaluation. Results: Results were analyzed using Post Hoc Bonferroni test (statistics is not a form of tabulation. Cervical scores of control were more than the exprimental groups (P 0.05. Conclusion: Class II composite restorations with centripetal build-up alone or when placed with CST reduces the cervical microleakage when compared to OST.

  6. Dental materials and their performance for the management of screw access channels in implant-supported restorations.

    Science.gov (United States)

    Raab, Philipp; Alamanos, Christos; Hahnel, Sebastian; Papavasileiou, Dimitrios; Behr, Michael; Rosentritt, Martin

    2017-03-31

    Unsuccessfully sealed screw access channels of prosthetic implant abutments may lead to malodor or peri-implant diseases in gingival tissues adjacent to implant-supported restorations. Therefore, 72 sets of screw channel analogs with six different materials incorporated (Polytetrafluoroethylene (PTFE), wax, gutta-percha, cavit, endofrost-pellets and cotton pellets) were exposed (2.5 h, 37°C) to Streptococcus mutans, oralis and Candida albicans suspensions. Bacterial adherence was quantified by using the fluorescence dye, Alamar Blue/resazurin, and an automated multifunctional reader. For quantification of fungal adherence the ATP-based bioluminescence approach was used. High relative fluorescence and luminescence intensities (>10,000), indicating high adhesion of streptococci and fungi were found for cotton and endofrost-pellets and low intensities (wax, gutta-percha, cavit and PTFE. The quantity of bacterial and fungal adhesion differed significantly between the assessed various sealing materials. In conclusion and within the limitations of this study, wax, gutta-percha, cavit and PTFE should be preferred as sealing materials.

  7. Influence of different composite materials and cavity preparation designs on the fracture resistance of mesio-occluso-distal inlay restoration.

    Science.gov (United States)

    Tekçe, Neslihan; Pala, Kansad; Demirci, Mustafa; Tuncer, Safa

    2016-01-01

    The aim of the study to evaluate the fracture resistance of a computer-aided design/computer-aided manufacturing (CAD/CAM) and three indirect composite materials for three different mesio-occluso-distal (MOD) inlay cavity designs. A total of 120 mandibular third molar were divided into three groups: (G1) non-proximal box, (G2) 2-mm proximal box, and (G3) 4-mm proximal box. Each cavity design received four composite materials: Estenia, Epricord (Kuraray, Japan), Tescera (Bisco, USA), and Cerasmart CAD/CAM blocks (GC, USA). The specimens were subjected to a compressive load at a crosshead speed of 1 mm/min. The data was analyzed using the two-way analysis of variance and Bonferroni post hoc test (p<0.05). Estenia exhibited significantly higher fracture strength than Epricord and Cerasmart in G1. In G2 and G3, there was no significant difference among the four materials. Using a non-proximal box design for the cavity can improve the fracture resistance of the inlay restoration.

  8. Apical Sealing Ability of Mineral Trioxide Aggregate, Intermediate Restorative Material and Calcium Enriched Mixture Cement: A Bacterial Leakage Study

    Science.gov (United States)

    Shahriari, Shahriar; Faramarzi, Farhad; Alikhani, Mohammad-Yousef; Farhadian, Maryam; Hendi, Seyedeh Sareh

    2016-01-01

    Introduction: This in vitro study compared the apical sealing ability of three common root end filling materials namely mineral trioxide aggregate (MTA), intermediate restorative material (IRM) and calcium-enriched mixture (CEM) cement using a bacterial leakage model. Methods and Materials: The study was conducted on 83 single-rooted human teeth. Tooth crowns were cut and root canals were prepared using the step-back technique. Apical 3 mm of the roots were cut and a three-mm-deep cavity was prepared using an ultrasonic instrument. The samples were divided into three groups (n=25) according to the root-end filling material including MTA, IRM and CEM cement. The roots were inserted into cut-end microtubes. After sterilization with ethylene oxide, microtubes were placed in sterile vials containing 10 mL of Brain Heart Infusion (BHI) broth and incubated at 37°C and 0.1 mL of Enterococcus faecalis suspension compatible with 0.5 McFarland standard (1.5×108 cell/ ml), which was refreshed daily. This procedure was continued for 70 days. The data were analyzed using the chi-square, Kruskal-Wallis and log rank tests. The level of significance was set at 0.05. Results: No significant difference was found in bacterial microleakage among three groups; MTA showed slightly (but not significantly) less microleakage than IRM and CEM. However, the difference in the mean time of microleakage was significant among the groups (P<0.04) and in MTA samples leakage occurred in a longer time than CEM (P<0.012). Conclusion: The three tested root end filling materials had equal sealing efficacy for preventing bacterial leakage. PMID:27790267

  9. In Vitro Screening of the Apatite-Forming Ability, Biointeractivity and Physical Properties of a Tricalcium Silicate Material for Endodontics and Restorative Dentistry

    OpenAIRE

    Maria Giovanna Gandolfi; Francesco Siboni; Antonella Polimeni; Maurizio Bossù; Francesco Riccitiello; Sandro Rengo; Carlo Prati

    2013-01-01

    Aim: Calcium silicate-based materials are hydraulic self-setting materials with physico-chemical properties suitable for endodontic surgery and good biological/clinical outcomes. The study aim was to evaluate the bio-properties (biointeractivity and apatite-forming ability) and selected physical properties (porosity, water sorption, solubility, and setting time) of Biodentine, a tricalcium silicate material for endodontics and restorative dentistry, compared to that of ProRoot MTA (Mineral ...

  10. Restorative dentistry for children.

    Science.gov (United States)

    Donly, Kevin J

    2013-01-01

    This article discusses contemporary pediatric restorative dentistry. Indications and contraindications for the choice of different restorative materials in different clinical situations, including the risk assessment of the patient, are presented. The specific use of glass ionomer cement or resin-modified glass ionomer cement, resin-based composite, and stainless steel crowns is discussed so that preparation design and restoration placement is understood.

  11. EVALUATION OF BPA LEVELS RELEASED FROM DIFFERENT DENTAL RESTORATIVE MATERIALS USING HPLC METHOD

    OpenAIRE

    ASCİ, Ali; DERELİOGLU, Sera Simsek; YİLMAZ, Bilal; GURBUZ, Taskin; SONGUR, Fatma

    2017-01-01

    Bisphenol A(BPA) is a chemical produced in large quantities for use primarily in theproduction of polycarbonate plastics and epoxy resins. BPA is also present indental materials used to treat and prevent caries. There have been concernsraised regarding the safety of bisphenol A in dental sealants and composites.The aim of the study is to measure BPA levels which were released fromcomposite resins after curing with different polymerization conditions. Fourcomposite resins which are commonly us...

  12. RECYCLED WASTE-BASED CEMENT COMPOSITE PATCH MATERIALS FOR RAPID/PERMANENT ROAD RESTORATION.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2001-07-31

    Over the past year, KeySpan Energy sponsored a research program at Brookhaven National Laboratory (BNL) aimed at recycling boiler ash (BA) and waste water treatment sludge (WWTS) byproducts generated from Keyspan's power stations into potentially useful materials, and at reducing concurrent costs for their disposal. Also, KeySpan has an interest in developing strategies to explicitly integrate industrial ecology and green chemistry. From our collaborative efforts with Keyspan (Diane Blankenhom Project Manager, and Kenneth Yager), we succeeded in recycling them into two viable products; Pb-exchange adsorbents (PEAs), and high-performance cements (HpCs). These products were made from chemically bonded cement and ceramic (CBC) materials that were synthesized through two-step chemical reaction pathways, acid-base and hydration. Using this synthesis technology, both the WWTS and BA served in acting as solid base reactants, and sodium polyphosphate, [-(-NaPO{sub 3}-)-{sub n}], known as an intermediator of fertilizer, was employed as the acid solution reactant. In addition, two commercial cement additives, Secar No. 51 calcium aluminate cement (CAC) and Type I calcium silicate cement (CSC), were used to improve mechanical behavior and to promote the rate of acid-base reaction of the CBC materials.

  13. Restoring marsh elevation in a rapidly subsiding salt marsh by thin-layer deposition of dredged material

    Science.gov (United States)

    Ford, M.A.; Cahoon, D.R.; Lynch, J.C.

    1999-01-01

    Thin-layer deposition of dredged material on coastal marsh by means of high-pressure spray dredging (Jet-Spray??2) technology has been proposed as a mechanism to minimize wetland impacts associated with traditional bucket dredging technologies and to restore soil elevations in deteriorated marshes of the Mississippi River delta. The impact of spray dredging on vegetated marsh and adjacent shallow-water habitat (formerly vegetated marsh that deteriorated to open water) was evaluated in a 0.5-ha Spartina alterniflora-dominated salt marsh in coastal Louisiana. The thickness of dredged sediment deposits was determined from artificial soil marker horizons and soil elevation change was determined from sedimentation-erosion tables (SET) established prior to spraying in both sprayed and reference marshes. The vertical accretion and elevation change measurements were made simultaneously to allow for calculation of shallow (~5 m depth) subsidence (accretion minus elevation change). Measurements made immediately following spraying in July 1996 revealed that stems of S. alterniflora were knocked down by the force of the spray and covered with 23 mm of dredged material. Stems of S. alterniflora soon recovered, and by July 1997 the percent cover of S. alterniflora had increased three-fold over pre-project conditions. Thus, the layer of dredged material was thin enough to allow for survival of the S. alterniflora plants, with no subsequent colonization by plant species typical of higher marsh zones. By February 1998, 62 mm of vertical accretion accumulated at this site, and little indication of disturbance was noted. Although not statistically significant, soil elevation change was greater than accretion on average at both the spray and reference marshes, suggesting that subsurface expansion caused by increased root biomass production and/or pore water storage influence elevation in this marsh region. In the adjacent shallow water pond, 129 mm of sediment was deposited in July

  14. Biogenic Hydroxyapatite: A New Material for the Preservation and Restoration of the Built Environment.

    Science.gov (United States)

    Turner, Ronald J; Renshaw, Joanna C; Hamilton, Andrea

    2017-09-20

    Ordinary Portland cement (OPC) is by weight the world's most produced man-made material and is used in a variety of applications in environments ranging from buildings, to nuclear wasteforms, and within the human body. In this paper, we present for the first time the direct deposition of biogenic hydroxyapatite onto the surface of OPC in a synergistic process which uses the composition of the cement substrate. This hydroxyapatite is very similar to that found in nature, having a similar crystallite size, iron and carbonate substitution, and a semi-crystalline structure. Hydroxyapatites with such a structure are known to be mechanically stronger and more biocompatible than synthetic or biomimetic hydroxyapatites. The formation of this biogenic hydroxyapatite coating therefore has significance in a range of contexts. In medicine, hydroxyapatite coatings are linked to improved biocompatibility of ceramic implant materials. In the built environment, hydroxyapatite coatings have been proposed for the consolidation and protection of sculptural materials such as marble and limestone, with biogenic hydroxyapatites having reduced solubility compared to synthetic apatites. Hydroxyapatites have also been established as effective for the adsorption and remediation of environmental contaminants such as radionuclides and heavy metals. We identify that in addition to providing a biofilm scaffold for nucleation, the metabolic activity of Pseudomonas fluorescens increases the pH of the growth medium to a suitable level for hydroxyapatite formation. The generated ammonia reacts with phosphate in the growth medium, producing ammonium phosphates which are a precursor to the formation of hydroxyapatite under conditions of ambient temperature and pressure. Subsequently, this biogenic deposition process takes place in a simple reaction system under mild chemical conditions and is cheap and easy to apply to fragile biological or architectural surfaces.

  15. Wear mechanisms of dental composite restorative materials by two different in-vitro methods

    Directory of Open Access Journals (Sweden)

    Juliana Antonino de Souza

    2013-04-01

    Full Text Available In this work two very simple apparatuses, namely the ball crater (or ball-on-plate and the linear reciprocating (or pin-on-plate tests, were used in order to investigate the wear mechanisms of TPH Spectrum® and Resilab Master® dental composite resins. Loads in the range of 100 g to 1 kg and a total number of up to 24000 cycles were employed. During some of these tests, aqueous aluminum oxide suspensions were used as abrasive agent either diluted or not in distilled water. In case of the ball-on-plate test wear is dominated by abrasive and/or adhesive mechanisms, and is characterized by scratches which are composed of wear defects comprising particle detachment, wear of the polymer matrix and ceramic particle abrasion. However, the relative contributions of the two wear mechanisms could not be determined separately. In case of the pin-on-plate test wear is governed by the fatigue mechanism, although abrasive and adhesive wear mechanism are also present. After a certain number of cycles fatigue wear dominates the wear behavior and results in severe material loss. This mechanism seems to be more important in case of more brittle materials and when higher loads are employed. Qualitative analysis of the results suggests that the combination of these two very simple methods under appropriate conditions can yield sound results which may be representative of a number of clinical situations.

  16. Wear mechanisms of dental composite restorative materials by two different in-vitro methods

    Directory of Open Access Journals (Sweden)

    Juliana Antonino de Souza

    2012-01-01

    Full Text Available In this work two very simple apparatuses, namely the ball crater (or ball-on-plate and the linear reciprocating (or pin-on-plate tests, were used in order to investigate the wear mechanisms of TPH Spectrum® and Resilab Master® dental composite resins. Loads in the range of 100 g to 1 kg and a total number of up to 24000 cycles were employed. During some of these tests, aqueous aluminum oxide suspensions were used as abrasive agent either diluted or not in distilled water. In case of the ball-on-plate test wear is dominated by abrasive and/or adhesive mechanisms, and is characterized by scratches which are composed of wear defects comprising particle detachment, wear of the polymer matrix and ceramic particle abrasion. However, the relative contributions of the two wear mechanisms could not be determined separately. In case of the pin-on-plate test wear is governed by the fatigue mechanism, although abrasive and adhesive wear mechanism are also present. After a certain number of cycles fatigue wear dominates the wear behavior and results in severe material loss. This mechanism seems to be more important in case of more brittle materials and when higher loads are employed. Qualitative analysis of the results suggests that the combination of these two very simple methods under appropriate conditions can yield sound results which may be representative of a number of clinical situations.

  17. Evaluation of radiation effects on dental enamel hardness and dental restorative materials; Avaliacao do efeito da irradiacao na dureza do esmalte dental e de materiais odontologicos

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Lena Katekawa; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Supervisao de Radioquimica; Campos, Tomie Nakakuki [Sao Paulo Univ., SP (Brazil). Faculdade de Odontologia. Dept. de Protese

    2000-07-01

    This research presents the results of the microhardness of human dental enamel and of the following dental restorative materials: three dental porcelains - Ceramco II, Finesse and Noritake, and two resin restorative materials - Artglass and Targis, for materials submitted to different times of irradiation at the IEA-R1m nuclear reactor under a thermal neutron flux of 10{sup 12}n cm{sup -2}.s{sup -1} . The results obtained indicated that there is a decrease of the surface microhardness when the enamel is irradiated for 1 h and when dental materials are irradiated for 3 h. However, enamels irradiated for 30 min. did not show significant change of their surface hardness. Therefore, the selection of irradiation time is an important factor to be considered when irradiated teeth or dental materials are used in the investigations of their properties. (author)

  18. Adhesion of Streptococcus mutans to Zirconia, Titanium Alloy and some other Restorative Materials: “An in-vitro Study”

    Directory of Open Access Journals (Sweden)

    Ezzatollah Jalalian

    2015-04-01

    Full Text Available Introduction: Bacterial adhesion on restorative materials may lead to gingival inflammation and secondary caries. Objectives: The aim of this in vitro study was to evaluate the adhesion of streptococcus mutans to zirconia, Feldespatic porcelain, titanium alloy and Indirect composite resin In-vitro. The effect of surface roughness on bacterial adhesion was also studied. Materials and Methods: 10 specimens (5mm diameter, 1mm thickness of each material, Zirconia, Indirect composite resin, Titanium alloy and Feldespatic porcelain were fabricated. Enamel was used as reference. Specimens were covered with artificial saliva and bacterial suspension (109 CFU/mL. Bacterial adhesion was determined using scanning electron microscope and culturing the specimens in blood agar. Data were analyzed with One way ANOVA followed by Tukey post hoc test for roughness and Kruskal-wallis test for adhesion values. Results: The highest bacterial adhesion was recorded for composite specimens and the lowest was seen in Ziconia group (p<0.5. The mean value of adhesion for zirconia, feldespatic peocelain, Titanium alloy and indirect composite were 28±6.32, 40.80±8.40, 75±4.47 and 386±13.75, respectively. The differences between zirconia and titanium alloy and also zirconia and indirect composite and porcelain and indirect composite were statistically significant (p<0.5. Conclusion: Zirconia showed the lowest bacterial adhesion in comparison to other tested materials and Enamel. The difference between zirconia and titanium alloy and also zirconia and indirect composite was statistically significant (p<0.5. No correlation was found between surface roughness and bacterial adhesion.   Keywords: Bacterial adhesions; Streptococcus mutans; Dental caries

  19. The chewing robot: a new biologically-inspired way to evaluate dental restorative materials.

    Science.gov (United States)

    Raabe, D; Alemzadeh, K; Harrison, A L; Ireland, A J

    2009-01-01

    This paper presents a novel in vitro dental wear simulator based on 6-6 parallel kinematics to replicate mechanical wear formation on dental materials and components, such as individual teeth, crowns or bridges. The human mandible, guided by a range of passive structures moves with up to six degrees of freedom (DOF). Currently available wear simulators lack the ability to perform these complex chewing movements. In addition simulators are unable to replicate the normal range of chewing forces as they have no control system able to mimic the natural muscle function controlled by the human central nervous system. Such discrepancies between true in vivo and simulated in vitro movements will influence the outcome and reliability of wear studies using such approaches. This paper summarizes the development of a new dynamic jaw simulator based on the kinematics of the human jaw.

  20. An in vitro study of dental enamel wear by restorative materials using radiometric method; Estudo in vitro do desgaste do esmalte dental pelos materiais restauradores utilizando metodo radiometrico

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Lena Katekawa

    2000-07-01

    There is an increasing demand and interest to study the dental materials wear as well as about the abrasion effect on antagonistic teeth. Due to the fact that the existent restorative materials have no specifications about their abrasiveness, it is necessary the establishment of degrees of comparison among them to support clinical application. In this work, the radiometric method was applied to study the enamel wear caused by another enamel and by restorative materials (Ceramco II, Noritake and Finesse porcelains, Artglass and Targis). The dental enamel made radioactive by irradiation at the IEA-R1m nuclear research reactor under a thermal neutron flux was submitted to wear in a machine which allows sliding motion of an antagonistic surface in contact with this radioactive enamel. The enamel wear was evaluated by measuring beta activity of {sup 32}P transferred to water from this irradiated tooth. Results obtained indicated that dental porcelains cause pronounced enamel wear when compared with that provoked by another enamel or by resin materials. Resin materials caused less enamel wear than another enamel. Vickers microhardness data obtained for antagonistic materials showed a correlation with the wear caused to the enamel. This study allowed to conclude that the radiometric method proposed can be used satisfactorily in the evaluation of enamel wear by restorative materials. This method presents advantages due to quick responses and ease of analyses There is (author)

  1. A new approach to influence contact angle and surface free energy of resin-based dental restorative materials.

    Science.gov (United States)

    Rüttermann, Stefan; Trellenkamp, Taina; Bergmann, Nora; Raab, Wolfgang H-M; Ritter, Helmut; Janda, Ralf

    2011-03-01

    The purpose of the present study was to identify novel delivery systems and active agents which increase the water contact angle and reduce the surface free energy when added to resin-based dental restorative materials. Two delivery systems based on zeolite or novel polymeric hollow beads (Poly-Pore), loaded with two low surface tension active agents (hydroxy functional polydimethylsiloxane and polydimethylsiloxane) or a polymerizable active agent (silicone polyether acrylate) were used to modify commonly formulated experimental dental resin composites. The non-modified resin was used as a standard (ST). Flexural strength, flexural modulus, water sorption, solubility, polymerization shrinkage, surface roughness Ra, contact angle θ, total surface free energy γS, and the apolar γSLW, polar γSAB, Lewis acid γS+ and base γS- components, and the active agents surface tensions γL were determined (Pmaterials had significantly higher θ but significantly lower γS, γSAB and γS- than the ST. A Poly-Pore/polydimethyl siloxane delivery system yielded the highest θ (110.9±3.5°) acceptable physical properties and the lowest values for γSLW and γS-. Among the modified materials the polymerizable materials containing active agents had the lowest γAB and the highest γS+ and γS-. Although not significant, both of the zeolite delivery systems yielded higher γSLW, γS+ and γS- but lower γSAB than the Poly-Pore delivery systems. Poly-Pore based delivery systems highly loaded with low surface tension active agents were found not to influence the physical properties but to significantly increase the water contact angle and thus reduce surface free energy of dental resin composites.

  2. A 3-year prospective study of implant-supported, single-tooth restorations of all-ceramic and metal-ceramic materials in patients with tooth agenesis

    DEFF Research Database (Denmark)

    Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten

    2013-01-01

    OBJECTIVES: The purpose of this clinical study was to describe outcome variables of all-ceramic and metal-ceramic implant-supported, single-tooth restorations. MATERIALS AND METHODS: A total of 59 patients (mean age: 27.9 years) with tooth agenesis and treated with 98 implant-supported single...

  3. Characterization of Small Focal Renal Lesions: Diagnostic Accuracy with Single-Phase Contrast-enhanced Dual-Energy CT with Material Attenuation Analysis Compared with Conventional Attenuation Measurements.

    Science.gov (United States)

    Marin, Daniele; Davis, Drew; Roy Choudhury, Kingshuk; Patel, Bhavik; Gupta, Rajan T; Mileto, Achille; Nelson, Rendon C

    2017-09-01

    Purpose To determine whether single-phase contrast material-enhanced dual-energy material attenuation analysis improves the characterization of small (1-4 cm) renal lesions compared with conventional attenuation measurements by using histopathologic analysis and follow-up imaging as the clinical reference standards. Materials and Methods In this retrospective, HIPAA-compliant, institutional review board-approved study, 136 consecutive patients (95 men and 41 women; mean age, 54 years) with 144 renal lesions (111 benign, 33 malignant) measuring 1-4 cm underwent single-energy unenhanced and contrast-enhanced dual-energy computed tomography (CT) of the abdomen. For each renal lesion, attenuation measurements were obtained; attenuation change of greater than or equal to 15 HU was considered evidence of enhancement. Dual-energy attenuation measurements were also obtained by using iodine-water, water-iodine, calcium-water, and water-calcium material basis pairs. Mean lesion attenuation values and material densities were compared between benign and malignant renal lesions by using the two-sample t test. Diagnostic accuracy of attenuation measurements and dual-energy material densities was assessed and validated by using 10-fold cross-validation to limit the effect of optimistic bias. Results By using cross-validated optimal thresholds at 100% sensitivity, iodine-water material attenuation images significantly improved specificity for differentiating between benign and malignant renal lesions compared with conventional enhancement measurements (93% [103 of 111]; 95% confidence interval: 86%, 97%; vs 81% [90 of 111]; 95% confidence interval: 73%, 88%) (P = .02). Sensitivity with iodine-water and calcium-water material attenuation images was also higher than that with conventional enhancement measurements, although the difference was not statistically significant. Conclusion Contrast-enhanced dual-energy CT with material attenuation analysis improves specificity for

  4. Liberação de flúor de materiais restauradores Fluoride releasing of restorative materials

    Directory of Open Access Journals (Sweden)

    Adriana Silva de CARVALHO

    1998-10-01

    Full Text Available Atualmente no mercado odontológico existem diversos tipos de materiais restauradores que liberam flúor com o objetivo de diminuir ou eliminar as cáries recorrentes. Considerando-se a diferença de composição desses materiais, foi avaliada sua capacidade de liberação de flúor. Foram avaliados os materiais restauradores: Chelon-fil (ESPE, Vitremer (3M, Variglass (Dentsply, Dyract (Dentsply e Tetric (Vivadent. Confeccionaram-se seis amostras cilíndricas (área = 1,65 cm2 de cada material, as quais foram imersas individualmente em 2,0 ml de água deionizada, que foi trocada diariamente durante 15 dias. A liberação de flúor foi determinada após adição de volume igual de tampão TISAB II às soluções. Para a análise da concentração de flúor foi utilizado um eletrodo específico para flúor Orion 96-09, acoplado a um analisador de íons Orion EA-940. Todos os materiais seguiram o mesmo padrão de liberação de flúor. As maiores médias de flúor liberado dentro de cada material foram encontradas no 1º dia, decrescendo bruscamente no 2º e 3º dias, e a quantidade de flúor liberado apresentou um decréscimo com o passar dos dias até atingir um nível quase constante. A liberação média de flúor durante o período de avaliação (média e desvio padrão em µg F/cm2 foi: CHE = 7,62 ± 0,76A, VIT = 5,91 ± 0,79B, VAR = 2,72 ± 0,25C, DYR = 1,50 ± 0,17 D, TET = 0,136 ± 0,016 E. Médias seguidas por letras distintas diferem entre si ao nível de significância de 5% (Tukey. Os resultados mostraram que a composição dos materiais restauradores influencia de maneira significativa sua liberação de flúor.Nowadays there are several types of restorative materials with fluoride release properties. Thus, the purpose of this study was to analyze the fluoride release from the following restorative materials, considering their different compositions. The materials used were: Chelon Fil-ESPE (CHE, Vitremer-3M (VIT, Variglass

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

    Science.gov (United States)

    Sripathi Panditaradhyula, Anuhya

    of these specimens were done by placing the respective specimens in distilled water, ascorbic acid (pH=1.5) and NaOH (pH=13). These resins were not fully cured with filler apart from filled 25:75 oxirane: acrylate cured best. Replacing 4-(Octyloxy) phenyl] phenyl iodonium SbF6 (OPPI) with 4-Isopropyl-4'- methyldiphenyl iodonium Tetrakis (pentafluorophenyl borate (Borate) initiator enhanced 24hr oxirane cure. Formulations had greater hardness compared with the controls. The increase in hardness was due to Increase in oxirane functionality, Increase in filler loading and use of acrylate-salinated filler. Modulus and ultimate transverse strength are greater than controls, but did not have statistically significance energy to break. Thus, these composites are as tough as controls and less brittle. They have the higher hydrophobicity than BisGMA: TEGDMA controls. Furthermore, other means of increasing hydrophobicity was explored, because higher the hydrophobicity, higher the resistance to hydrolytic degradation. Further research observations, such as dynamic mechanical analysis, should be carried out in order to determine the molecular interactions and usage of multi-walled, white carbon nanotubes as filler material.

  6. Machining accuracy of crowns by CAD/CAM system using TCP/IP: influence of restorative material and scanning condition.

    Science.gov (United States)

    Tomita, Sachiko; Shin-ya, Akiyoshi; Gomi, Harunori; Shin-ya, Akikazu; Yokoyama, Daiichiro

    2007-07-01

    The purpose of this study was to determine the optimal condition for fabricating accurate crowns efficiently using an internet-based CAD/CAM system. The influences of three different CAD/CAM restorative materials (titanium, porcelain, and composite resin) and three different step-over scanning distances (0.01 mm, 0.11 mm, and 0.21 mm) were evaluated, and their interactive effects were carefully examined. Several points on the inner and outer surfaces of machined crowns - as well as height - were measured. These measurements were then compared with the original models, from which machining accuracy was obtained. At all measuring points, the inner surface of all crowns was machined larger than the die model, whereas the cervical area of porcelain crown was machined smaller than the crown model. Results of this study revealed that a step-over distance of 0.11 mm was an optimal scanning condition, taking into consideration the interactive effects of scanning time required, data volume, and machining accuracy.

  7. Evaluation of the effect of a home bleaching agent on surface characteristics of indirect esthetic restorative materials--part II microhardness.

    Science.gov (United States)

    Torabi, Kianoosh; Rasaeipour, Sasan; Ghodsi, Safoura; Khaledi, Amir Ali Reza; Vojdani, Mahroo

    2014-07-01

    The exponential usage of esthetic restorative materials is beholden to society needs and desires. Interaction between the bleaching agents and the esthetic restorative materials is of critical importance. This in vitro study has been conducted to evaluate the effect of a home bleaching agent, carbamide peroxide (CP) 38%, on the microhardness of the fiber reinforced composite (FRC), overglazed, autoglazed, or polished porcelain specimens. For overglazed, autoglazed, polished ceramics and also FRC cylindrical specimens (n = 20 per group) were prepared. The specimens were stored in distilled water at 37°C for 48 hours prior to testing. Six samples from each group were selected randomly as negative controls which were stored in distilled water at 37°C that was changed daily. CP 38% was applied on the test specimens for 15 minutes, twice a day for 14 days. By using Knoop-microhardness tester microhardness testing for baseline, control and test specimens was conducted. Data were statistically analyzed using paired t-test, Mann-Whitney test, and Kruskal-Wallis test. Home bleaching significantly decreased the surface microhardness of all the test samples (p materials is unavoidable. Therefore protecting these restorations from bleaching agents and reglazing or at least polishing the restorations after bleaching is recommended.

  8. Atraumatic restorative treatment in atypical cavities

    Directory of Open Access Journals (Sweden)

    Letícia Simino Carvalho

    2009-10-01

    Full Text Available The atraumatic restorative treatment has been widely divulged among professionals in the area of Pediatric Dentistry. This restorative technique is included in the philosophy of Minimal Intervention and is considered one of the most conservative treatments, because only the layer of infected dentin caries is removed. Moreover, the atraumatic restorative treatment has been shown to be less painful than conventional approaches, and local anesthesia is rarely required. After the removal of the infected dentin, the cavities are filled with glass ionomer cement, a material that has antimicrobial capacity, good marginal sealing and constant fluorine release and recharge. In spite of the increasing number of studies about atraumatic restorative treatment, only studies related to restorations in occlusal cavities have shown scientific evidences about the technique. The aim of this study was to evaluate the feasibility of atraumatic restorative treatment in cavities with 3 or more surfaces involved, by means of a clinical case report of a patient with extensive dstruction in primary teeth, who was submitted to atraumatic restorative treatment, and observe the result of the treatment after one year of clinical and radiographic control.

  9. Restoring the worn dentition.

    Science.gov (United States)

    Ibsen, R L; Ouellet, D F

    1992-01-01

    Strong dental materials and dental porcelains are providing dentists with restorative opportunities that are more conservative because they require less destruction of healthy tooth structure and yield a more esthetic result. In cases of severe wear due to attrition, abrasion, and erosion, this process can be stopped, restoring the esthetics and function by using proper techniques and materials. The case report described in this article demonstrates the conservative restoration of severe wear due to attrition and erosion. Teeth were lengthened, wear was restored, and further wear was ceased by using a combination of bonded porcelain, a heat, light, and self-cure resin system, and a new glass-ionomer restorative material. The result was a strong, durable restoration (that required no anesthesia) with high esthetics.

  10. Single unit CAD/CAM restorations: a literature review.

    Science.gov (United States)

    Freedman, Michael; Quinn, Frank; O'Sullivan, Michael

    2007-01-01

    Computer-aided design/computer-aided manufacture (CAD/CAM) has been used in dentistry since 1987. Since then, many CAD/CAM systems have been described, which enable the production of chair-side single unit dental restorations. These restorations are of comparable quality to those made by conventional techniques and have some specific advantages, including rapid production, improved wear properties, decreased laboratory fee and improved cross infection control. This literature review investigates the evidence base for the use of single unit CAD/CAM restorations. Materials, marginal gap, aesthetics, post-operative sensitivity, cementation, cost-effectiveness and longevity are discussed.

  11. Restoring the incisal edge.

    Science.gov (United States)

    Terry, Douglas A

    2005-01-01

    Restorative dentistry evolves with each development of new material and innovative technique. Selection of improved restorative materials that simulate the physical properties and other characteristics of natural teeth, in combination with restorative techniques such as the proximal adaptation and incremental layering, provide the framework that ensures the optimal development of an esthetic restoration. These advanced placement techniques offer benefits such as enhanced chromatic integration, polychromatism, ideal anatomical form and function, optimal proximal contact, improved marginal integrity and longer lasting directly placed composite restorations. The purpose of this article is to give the reader a better understanding of the complex restorative challenge in achieving true harmonization of the primary parameters in esthetics (that is, color, shape and texture) represented by the replacement of a single anterior tooth. The case presented demonstrates the restoration of a Class IV fracture integrating basic adhesive principles with these placement techniques and a recently developed nanoparticle hybrid composite resin system (Premise, Kerr/Sybron, Orange, CA). The clinical presentation describes preoperative considerations, tooth preparation, development of the body layer, internal characterization with tints, development of the artificial enamel layer, shaping and contouring, and polishing of a Class IV composite restoration. The clinical significance is that anterior tooth fractures can be predictably restored using contemporary small particle hybrid composite resin systems with the aforementioned restorative techniques. These placement techniques when used with proper attention to preparation design, adhesive protocol and finishing and polishing procedures, allow the clinician to successfully restore form, function and esthetics to the single anterior tooth replacement.

  12. The development and testing of glaze materials for application to the fit surface of dental ceramic restorations.

    Science.gov (United States)

    Cattell, Michael J; Chadwick, Thomas C; Knowles, Jonathan C; Clarke, Richard L

    2009-04-01

    The aims of the study were to develop and test overglaze materials for application to the fit surface of dental ceramic restorations, which could be etched and adhesively bonded and increase the flexural strength of the ceramic substrate. Three glaze materials were developed using commercial glass powders (P25 and P54, Pemco, Canada). P25 (90 wt%) was mixed with P54 (10 wt%) to produce (P25/P54). P54 (90 wt%) was mixed with P25 (10 wt%) to produce (P54/P25). P25 (90 wt%) was mixed with 10 wt% of an experimental glass powder (P25/frit). Eighty-two disc specimens (14 mm x 2 mm) were produced by heat pressing a leucite glass-ceramic and were sandblasted with 50 microm glass beads. Group 1 control specimens (10) were sandblasted. Groups 2-4 (10 per group) were coated using P25/frit (Group 2), P25/P54 (Group 3) and P54/P25 (Group 4) overglazes before sintering. Groups 1-4 were etched for 2 min using 9.5% HF (Gresco, USA). Composite cylinders (Marathon v, Den-Mat) were light cured and bonded to the glazed and prepared disc surfaces and groups water stored for 8 days. Groups were tested using shear bond strength (SBS) testing at 0.5mm/min. Disc specimens (42) were tested using the biaxial flexural strength (BFS) test at a crosshead speed of 0.15 mm/min. Group 1 was tested as sandblasted (21) and Group 2 (21) after coating the tensile surface with P25/frit. Xrd, Eds and Sem analyzes were carried out. Mean SBS (MPa+/-S.D.) were: Group 1: 10.7+/-2.1; Group 2: 9.8+/-1.9; Group 3: 1.8+/-1.0 and Group 4: 2.6+/-1.7. Groups 1 and 2 were statistically different to Groups 3 and 4 (p0.05). The mean BFS (MPa+/-S.D.) of the overglazed Group 2 (200.2+/-22.9) was statistically different (pceramic substrate and produced comparable shear bond strengths to an etched and bonded control. The application of etched overglaze materials to dental glass-ceramic and ceramic substrates may be useful in adhesive dentistry.

  13. Evaluation of the effect of tooth and dental restoration material on electron dose distribution and production of photon contamination in electron beam radiotherapy.

    Science.gov (United States)

    Bahreyni Toossi, Mohammad Taghi; Ghorbani, Mahdi; Akbari, Fatemeh; Mehrpouyan, Mohammad; Sobhkhiz Sabet, Leila

    2016-03-01

    The aim of this study is to evaluate the effect of tooth and dental restoration materials on electron dose distribution and photon contamination production in electron beams of a medical linac. This evaluation was performed on 8, 12 and 14 MeV electron beams of a Siemens Primus linac. MCNPX Monte Carlo code was utilized and a 10 × 10 cm(2) applicator was simulated in the cases of tooth and combinations of tooth and Ceramco C3 ceramic veneer, tooth and Eclipse alloy and tooth and amalgam restoration materials in a soft tissue phantom. The relative electron and photon contamination doses were calculated for these materials. The presence of tooth and dental restoration material changed the electron dose distribution and photon contamination in phantom, depending on the type of the restoration material and electron beam's energy. The maximum relative electron dose was 1.07 in the presence of tooth including amalgam for 14 MeV electron beam. When 100.00 cGy was prescribed for the reference point, the maximum absolute electron dose was 105.10 cGy in the presence of amalgam for 12 MeV electron beam and the maximum absolute photon contamination dose was 376.67 μGy for tooth in 14 MeV electron beam. The change in electron dose distribution should be considered in treatment planning, when teeth are irradiated in electron beam radiotherapy. If treatment planning can be performed in such a way that the teeth are excluded from primary irradiation, the potential errors in dose delivery to the tumour and normal tissues can be avoided.

  14. Site Restoration

    Energy Technology Data Exchange (ETDEWEB)

    Noynaert, L.; Bruggeman, A.; Cornelissen, R.; Massaut, V.; Rahier, A

    2002-04-01

    The objectives, the programme, and the achievements of SCK-CEN's Site Restoration Department for 2001 are described. Main activities include the decommissioning of the BR3 PWR-reactor as well as other clean-up activities, projects on waste minimisation and the management of spent fuel and the flow of dismantled materials and the recycling of materials from decommissioning activities based on the smelting of metallic materials in specialised foundries. The department provides consultancy and services to external organisations and performs R and D on new techniques including processes for the treatment of various waste components including the reprocessing of spent fuel, the treatment of tritium, the treatment of liquid alkali metals into cabonates through oxidation, the treatment of radioactive organic waste and the reconditioning of bituminised waste products.

  15. Effect of professional dental prophylaxis on the surface gloss and roughness of CAD/CAM restorative materials.

    Science.gov (United States)

    Sugiyama, Toshiko; Kameyama, Atsushi; Enokuchi, Tomoka; Haruyama, Akiko; Chiba, Aoi; Sugiyama, Setsuko; Hosaka, Makoto; Takahashi, Toshiyuki

    2017-06-01

    This study aimed to evaluate the effect of dental prophylaxis on the surface gloss and roughness of different indirect restorative materials for computer-aided design/computer-aided manufacturing (CAD/CAM): two types of CAD/CAM composite resin blocks (Shofu Block HC and Estelite Block) and two types of CAD/CAM ceramic blocks (IPS Empress CAD and Celtra DUO). After polishing the CAD/CAM blocks and applying prophylaxis pastes, professional dental prophylaxis was performed using four different experimental protocols (n = 5 each): mechanical cleaning with Merssage Regular for 10 s four times (Group 1); four cycles of mechanical cleaning with Merssage Regular for 10 s and Merssage Fine for 10 s (Group 2); four cycles of mechanical cleaning with Merssage Regular for 10 s and Merssage Fine for 30 s (Group 3); and mechanical cleaning with Merssage Fine for 10 s four times (Group 4). A glossmeter was used to measure surface gloss before and after mechanical cleaning, and a contact stylus profilometer was used to measure surface roughness (Ra). Polishing with prophylactic paste led to a significant reduction in surface gloss and increase in surface roughness among resin composite blocks, whereas the polishing-related change in surface gloss or roughness was smaller in Celtra DUO, a zirconia-reinforced lithium silicate block. Changes in surface gloss and roughness due to polishing with a prophylactic paste containing large particles were not improved by subsequent polishing with a prophylactic paste containing fine particles. Key words:CAD/CAM, professional dental prophylaxis, prophylactic paste, surface gloss, surface roughness.

  16. Role of colors in prosthodontics: Application of color science in restorative dentistry

    Directory of Open Access Journals (Sweden)

    Vinaya Bhat

    2011-01-01

    Full Text Available Shade selection procedure depends on various factors including translucency, contour and surface texture. Tooth shade selection using a conventional means involves a high degree of subjectivity. Traditional shade guides are available that use several methods for quantifying shade. Technology-based systems provide with an advantage of natural looking restorations. They include RGB devices, colorimeters, spectrophotometers. The impact of the color science can be seen on various restorative materials ranging from ceramics to maxillofacial prosthetic materials.

  17. Role of colors in prosthodontics: application of color science in restorative dentistry.

    Science.gov (United States)

    Bhat, Vinaya; Prasad, D Krishna; Sood, Sonali; Bhat, Aruna

    2011-01-01

    Shade selection procedure depends on various factors including translucency, contour and surface texture. Tooth shade selection using a conventional means involves a high degree of subjectivity. Traditional shade guides are available that use several methods for quantifying shade. Technology-based systems provide with an advantage of natural looking restorations. They include RGB devices, colorimeters, spectrophotometers. The impact of the color science can be seen on various restorative materials ranging from ceramics to maxillofacial prosthetic materials.

  18. A 3-year prospective study of implant-supported, single-tooth restorations of all-ceramic and metal-ceramic materials in patients with tooth agenesis.

    Science.gov (United States)

    Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten; Gotfredsen, Klaus

    2013-10-01

    The purpose of this clinical study was to describe outcome variables of all-ceramic and metal-ceramic implant-supported, single-tooth restorations. A total of 59 patients (mean age: 27.9 years) with tooth agenesis and treated with 98 implant-supported single-tooth restorations were included in this study. Two patients did not attend baseline examination, but all patients were followed for 3 years. The implants supported 52 zirconia, 21 titanium and 25 gold alloy abutments, which retained 64 all-ceramic and 34 metal-ceramic crowns. At baseline and 3-year follow-up examinations, the biological outcome variables such as survival rate of implants, marginal bone level, modified Plaque Index (mPlI), modified Sulcus Bleeding Index (mBI) and biological complications were registered. The technical outcome variables included abutment and crown survival rate, marginal adaptation of crowns, cement excess and technical complications. The aesthetic outcome was assessed by using the Copenhagen Index Score, and the patient-reported outcomes were recorded using the OHIP-49 questionnaire. The statistical analyses were mainly performed by using mixed model of ANOVA for quantitative data and PROC NLMIXED for ordinal categorical data. The 3-year survival rate was 100% for implants and 97% for abutments and crowns. Significantly more marginal bone loss was registered at gold-alloy compared to zirconia abutments (P = 0.040). The mPlI and mBI were not significantly different at three abutment materials. The frequency of biological complications was higher at restorations with all-ceramic restorations than metal-ceramic crowns. Loss of retention, which was only observed at metal-ceramic crowns, was the most frequent technical complication, and the marginal adaptations of all-ceramic crowns were significantly less optimal than metal-ceramic crowns (P = 0.020). The professional-reported aesthetic outcome demonstrated significantly superior colour match of all-ceramic over metal

  19. An in-vitro study to compare the temperature rise in the pulp chamber by direct method using three different provisional restorative materials.

    Science.gov (United States)

    Piplani, Ankita; Suresh Sajjan, M C; Ramaraju, A V; Tanwani, Tushar; Sushma, G; Ganathipathi, G; Jagdish, K; Agrawal, Anil

    2016-01-01

    The provisional restorative materials in fixed prosthodontics are basically bis-GMA resins which releases exothermic temperature while polymerization which can damage the pulp. Intrapulpal temperature exceeding 42.5°C found to result in irreversible damage to the pulp. The remaining thickness of dentine after tooth preparation control the conduction of heat released by the resins. (1) To quantify the temperature changes in the pulp chamber using different provisional restorative materials. (2) To evaluate the peak temperature time of different materials used. (3) To compare the intrapulpal temperature changes with a variation in the width of the finish line. Two intact mandibular molars were selected and designated as Specimen A and B. Tooth preparation was done to prepare a finish line of 1.2 mm and 1 mm width, respectively. Three provisional restorative materials were considered and they were grouped as Group I-Cool temp, Group II-Protemp-4, Group III-Integrity. A J thermocouple probe was placed into the pulp chamber to determine the rise in temperature. The temperature was recorded during polymerization at 30-s intervals until the peak temperature was reached. The same procedure was repeated for fabricating remaining provisional crowns. A total of 45 provisional crowns were fabricated for each specimen. Kruskal-Wallis test revealed that there was a significant difference in the temperature changes associated with the provisional restorative materials used. All the three provisional restorative materials were compared for 1.2 mm and 1 mm wide finish line. Integrity produced the highest temperature rise and the maximum temperature recorded was 40.2°C in 1.2 mm wide finish line. However, for a 1 mm wide finish line, Protemp-4 produced the highest temperature rise and the maximum temperature recorded was 40.3°C. It was observed that peak temperatures with Specimen B were more when compared with Specimen A. Cool temp showed least temperature rise in the pulp

  20. Comparative evaluation of surface properties of enamel and different esthetic restorative materials under erosive and abrasive challenges: An in vitro study

    OpenAIRE

    2015-01-01

    Introduction: Noncarious tooth surface loss is a normal physiological process occurring throughout the life, but it can often become a problem affecting function, esthetics or cause pain. Aim: The purpose of this study was to assess the effect of erosive and abrasive challenges on the surface microhardness and surface wear of enamel and three different restorative materials, that is, nanofilled composite, microfilled composite and resin-modified glass ionomer cement (RMGIC) by using Vickers m...

  1. 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.

  2. Indirect posterior restorations using a new chairside microhybrid resin composite system.

    Science.gov (United States)

    Tay, F R; Wei, S H

    2001-01-01

    A plethora of choices is available as potential tooth-colored restoratives for the posterior dentition. Advances in adhesive technology and esthetic chairside microhybrid composite resins have permitted clinicians to perform inlay/onlay restorations. The use of adhesive indirect procedures offers advantages such as better control of polymerization shrinkage and anatomical form, when compared to conventional, direct restorative techniques. This article describes the use of a new chairside microhybrid composite system as an indirect restorative material, using semidirect and indirect techniques that can be accomplished within the realm of a dental operatory.

  3. Restoring Charlemagne’s chapel: historical consciousness, material culture, and transforming images of Aachen in the 1840s

    Directory of Open Access Journals (Sweden)

    Jenny H. Shaffer

    2012-12-01

    Full Text Available The 1840s offer crystallizing images of Charlemagne’s chapel at Aachen that continue to resonate. In this decade, the Carolingian building, restored in words and images by scholars, made an auspicious debut within the coalescing discipline of art history. Simultaneously, the well-known restoration of the extant medieval chapel, which began in the 1850s, found sure footing as the chapel’s columnar screen, which Napoleon had removed, was reinserted. While these co-existing, interrelated restoration movements – focused on the chapel’s dilapidated state and notions of its importance as an imperial, Christian, and German work – diverged in methods and results after mid-century, they remain central to understanding both the chapel in scholarship and the extraordinary monument in the town centre of Aachen today.

  4. Effect of conventional and experimental gingival retraction solutions on the tensile strength and inhibition of polymerization of four types of impression materials

    OpenAIRE

    Sérgio Sábio; Paulo Afonso Franciscone; José Mondelli

    2008-01-01

    In the present study, two types of tests (tensile strength test and polymerization inhibition test) were performed to evaluate the physical and chemical properties of four impression materials [a polysulfide (Permlastic), a polyether (Impregum), a condensation silicone (Xantopren) and a polyvinylsiloxane (Aquasil) ,3; when polymerized in contact with of one conventional (Hemostop) and two experimental (Vislin and Afrin) gingival retraction solutions. For the tensile strength test, the i...

  5. Evaluation of effects of ionizing radiation on materials used in dental restorations;Avaliacao dos efeitos da radiacao ionizante em materiais utilizados em restauracoes dentarias

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Mireia Florencio

    2009-07-01

    This work consisted of quantitative studies of the effects caused by ionizing radiation on materials used in dental restorations (Titanium, Amalgam, Resin Composite and Glass Ionomer) aiming the deleterious effects of radiotherapy when patients with tumors in head and neck, arising when the teeth are restored within in the field of radiation. Samples were submitted to X-ray beams of 6 MV from a linear accelerator, VARIAN 2100C model. The samples were analyzed by X-ray fluorescence techniques to compare the chemical composition before and after the irradiation. The sample were submitted to Geiger-Mueller detectors and the ionization chambers in order to verify any residual radiation in the samples. The samples were also analyzed by gamma spectrometry by a Germanium detector. These tests were performed to determine small changes in the composition in the samples due to the radiation interaction. The results of this study may encourage the development of new research for alternative materials in dental restorations that can contribute to improve the quality of life of those patients with tumors of the mouth. (author)

  6. Bast shoes as archaeological material: origin, classification, restoration (the case of the finds made in Sviyazhsk and Kazan

    Directory of Open Access Journals (Sweden)

    Abdullin Khalim M.

    2014-09-01

    Full Text Available The article is devoted to the study and restoration of footwear made of bast and birch bark in the 17th-19th centuries from the 2012-2013 archaeological excavations in Kazan and Sviyazhsk. Historical and archival research on the site combined with archaeological analysis allowed to clearly date each artifact. The study of archaeological footwear revealed the morphology of the items and their manufacturing technology. In order to preserve the unique finds, a system of restoration measures has been developed, which made it possible to restore the fiber structure. For conservation and restoration of the articles, a mixed methodology of processing archaeological finds made of textiles and wood has been applied. At the stage of items drying, a method that allowed retaining the form and color has been used. On the basis of analogies and the data of ethnography, it was determined that, according to the type of plaiting, the bast shoes found are characteristic of the local population, while a birch-bark unit refers to the northern (Novgorod variety, whereas a bast shoe with interwoven leather straps finds an analogy in Moscow and Yaroslavl.

  7. Creation of Polyurethane Injection Materials, Their Pilot-industrial Production, Development and Industrial Introduction of the Technology of Strengthening and Restoring the Operability of Damaged Constructions and Buildings

    Directory of Open Access Journals (Sweden)

    Marukha, V.І.

    2015-01-01

    Full Text Available Polyurethane and foam polyurethane fluid injection materials not conceding foreign analogues and technology technology of restoration and strengthening the operability of concrete and reinforced concrete structures and buildings damaged by cracks were developed. Normative and technical documentation on the injection materials and technological processes was created. The diagnosticrestoring complex for implementing the above technologies was designed, installed and utilized at the construction sites. The equipment is designed and manufactured; the technology of the research and industrial production of «A» and «B» components of injecting polyurethane materials is designed and developed. The pilot-scale batch is manufactured. Technological processes of preparation and application of the «A» and «B» componentsof the injecting materials in industrial conditions are worked out and implemented.

  8. The atraumatic restorative treatment (ART) approach for the management of dental caries.

    Science.gov (United States)

    Smales, Roger J; Yip, Hak-Kong

    2002-06-01

    There is worldwide interest in and increasing usage of the conservative atraumatic restorative treatment technique or approach for the restoration of primary and permanent teeth. However, most published data on the clinical performance of the newer, high-strength esthetic conventional glass-ionomer restorative cements marketed for the procedure have been derived from short-term studies. There have been very few reports comparing different types of restorative materials and methods of cavity preparation. In primary teeth, after 1 year, success rates have been approximately 80% to 95% for Class I and Class V single-surface restorations, 55% to 75% for Class II multisurface restorations, and 35% to 55% for Class III and Class IV restorations. In permanent teeth, after 2 to 3 years, success rates have been approximately 90% for Class I and Class V single-surface restorations, but little data have been reported for other restoration classes. Failures usually result from restoration losses, fractures, and wear. Further improvements in the design of hand instruments and in the mechanical properties of the newer glass-ionomer cements are required. Currently, use of the atraumatic restorative treatment approach should be restricted to restoration of single-surface caries lesions, especially in permanent teeth, and to sealing of occlusal fissures in selected teeth.

  9. Effects of calcium diet supplements on egg strength in conventional and furnished cages, and effects of 2 different nest floor materials.

    Science.gov (United States)

    Valkonen, E; Venäläinen, E; Rossow, L; Valaja, J

    2010-11-01

    Several studies have demonstrated a greater incidence of cracked eggs in furnished than in conventional cages. Hens kept in furnished cages may have greater bone strength, so they may lay eggs with weaker shells because they may utilize more calcium for bone mineralization and less for shell formation. The effects of increased dietary calcium content were therefore studied in 3-hen conventional and 8-hen furnished cages. In addition, the effects of 2 different nest floor materials were studied in furnished cages. A total of 1,216 Lohmann Selected Leghorn hens were housed in either furnished or conventional cages and offered either the normal calcium supplementation used in commercial diets (37 to 40 g of calcium/kg) or increased calcium supplementation (44 to 50 g of calcium/kg) consisting of added limestone for 3 consecutive feeding phases of 20, 16, and 16 wk. Dietary calcium had similar effects in both cage systems. Greater limestone supplementation increased the laying rate (P cages (P cage types in terms of total egg mass produced. The cage type had no effect on tibia-breaking strength. However, the specific gravity and ash content of tibias were higher in hens kept in furnished than in conventional cages (P cages is not caused by a possible calcium shortage resulting from high bone mineralization.

  10. Comparative study of P19 EC stem cell differentiation in between conventional hanging drop and the zebrafish chorion as a bio-derived material.

    Science.gov (United States)

    Dae Seok Na; Lee, Hwang; Sun Uk Kim; Chang Nam Hwang; Sang Ho Lee; Ji Yoon Kang; Jai Kyeong Kim; James Jungho Pak

    2008-07-01

    Various materials including glass and polymers have been widely used for stem cell culture due to their biocompatibility. However, the roles of these materials are fundamentally limited because they cannot realize or imitate the complex biological functions of living tissues, except in very simple cases. Here, the development of a bio-derived material suitable for stem cell culture and improvement of differentiation efficiency to specific cell lineages with no stimulating agents by using a chorion obtained from a fertilized zebrafish egg through the removal of the yolk and embryonic cell mass from the egg is reported. Mouse P19 EC stem cells introduced into the empty chorion form a uniform embryoid body (EB) without addition of any inducing agent. It is demonstrated that the zebrafish chorion with nanopores improves efficiencies greatly in the EB formation, cell proliferation, and lineage-specific differentiations compared to those of the conventional hanging drop culture method.

  11. Efficacy of four lining materials in sandwich technique to reduce microleakage in class II composite resin restorations.

    Science.gov (United States)

    Moazzami, S M; Sarabi, N; Hajizadeh, H; Majidinia, S; Li, Y; Meharry, M R; Shahrokh, H

    2014-01-01

    The aim of the present study was to evaluate the effect of four different sandwich techniques on gingival microleakage of Class II direct composite resin restorations. Fifty sound human premolars were selected and randomly divided into five groups (n=10). Class II box only cavities were prepared in one of the proximal surfaces of each tooth with a gingival margin located approximately 0.5 mm below the cemento-enamel junction. Group A (control) was restored incrementally with composite resin (Tetric Ceram). Groups B, C, D, and E were restored with the sandwich technique using a compomer (Compoglass F), flowable composite resin (Tetric Flow), self-cure composite resin (Degufill SC), or resin modified glass ionomer (Fuji II LC), respectively. After thermal-load cycling, the specimens were immersed in 0.5% basic fuschin for 24 hours. Dye penetration (10(-1) mm) was detected using a sectioning technique. Data were analyzed with repeated measurements and Duncan test at α=0.05. The least amount of microleakage was detected in the incremental group (1.28 ± 0.98). The sandwich technique using resin modified glass ionomer (7.99 ± 9.57) or compomer (4.36 ± 1.78) resulted in significantly more leakage than did the sandwich technique using flowable (1.50 ± 1.97) or self-cure composite (2.26 ± 1.52). According to the results of this study, none of the four sandwich technique composite resin restorations used in this study could reduce gingival microleakage to a greater degree than the incremental technique.

  12. Clinical Investigation of a New Bulk Fill Composite Resin in the Restoration of Posterior Teeth

    Science.gov (United States)

    2016-09-07

    Dental Restoration Failure of Marginal Integrity; Dental Caries; Unrepairable Overhanging of Dental Restorative Materials; Poor Aesthetics of Existing Restoration; Secondary Dental Caries Associated With Failed or Defective Dental Restorations; Fractured Dental Restorative Materials Without Loss of Materials; Fracture of Dental Restorative Materials With Loss of Material

  13. 2014 Materials Research Society (MRS) Spring Meeting (4/21-25/14), Moscone West Convention Center, San Francisco CA

    Science.gov (United States)

    2015-04-02

    metamaterials . Three general themes are explored: (1) Interaction of light with magnetized metastructures, in which phenomena such as symmetry breaking...of non- magnetic all-passive nonlinear-based metamaterials (e.g., electromagnetic diodes, passive non-biased Faraday rotators, etc); and (3) the...materials. On the one hand, metamaterials have enabled control over both the electric and magnetic fields of light. This control allows the permittivity

  14. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

    Science.gov (United States)

    Qamheya, Ala Hassan A.; Yeniyol, Sinem; Arısan, Volkan

    2015-01-01

    Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC) material in teeth construction to rehabilitate a complete denture wearer patient. PMID:26557392

  15. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

    Directory of Open Access Journals (Sweden)

    Ala Hassan A. Qamheya

    2015-01-01

    Full Text Available Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC material in teeth construction to rehabilitate a complete denture wearer patient.

  16. The effect of different restorative and abutment materials on marginal and internal adaptation of three-unit cantilever implant-supported fixed partial dentures: an in vitro study.

    Science.gov (United States)

    Kahramanoğlu, Erkut; Kulak-Özkan, Yasemin

    2013-12-01

    Passive fit is generally assumed to be a significant prerequisite for long-term implant success. The aim of this study was to evaluate the precision fit of three-unit implant-supported fixed partial dentures with different restorative and abutment materials on two implant systems: the Straumann and Astra Tech. Two mandibular epoxy resin models (one for each implant system) were fabricated, and two implants were inserted at the first and second molar region. Poly(vinyl siloxane) impression material was used to make the dental impression. For each implant system, fifteen models were fabricated, and each group was divided into three subgroups (group 1: titanium abutment with metal framework, group 2: titanium abutment with zirconium framework, group 3: zirconium abutment with zirconium framework). The replica technique was used to examine the marginal and internal gap values. For each restoration, 20 measurements were performed, totaling 1200 measurements for all groups. Data were evaluated statistically using ANOVA and LSD post hoc test (p study, marginal measurement values were found to be 46 to 87 μm. The marginal discrepancy of the tested materials could be considered clinically acceptable. © 2013 by the American College of Prosthodontists.

  17. A review on anterior teeth restorations

    Directory of Open Access Journals (Sweden)

    Gaurav Solanki

    2014-12-01

    Full Text Available Restorations of teeth have been a need of time since very long. As the time have passed, there have been different advances in the field of restorative materials and tooth restorations. Many newer restorative materials are now available to us for the purpose of tooth restorations still some of the older materials are materials of choice for a sector of society. This article focuses on few such restorative materials and also tells us about a few patents granted in such field.

  18. [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.

  19. Evaluation of bone substitute materials: comparison of flat-panel based volume CT to conventional multidetector CT.

    Science.gov (United States)

    Sauerbier, Sebastian; Duttenhoefer, Fabian; Sachlos, Elefterios; Haberstroh, Jörg; Scheifele, Christian; Wrbas, Karl-Thomas; Voss, Pit Jacob; Veigel, Egle; Smedek, Jörg; Ganter, Philip; Tuna, Taskin; Gutwald, Ralf; Palmowski, Moritz

    2013-10-01

    Over the last decade tissue engineering has emerged as a key factor in bone regeneration within the field of cranio-maxillofacial surgery. Despite this in vivo analysis of tissue-engineered-constructs to monitor bone rehabilitation are difficult to conduct. Novel high-resolving flat-panel based volume CTs (fp-VCT) are increasingly used for imaging bone structures. This study compares the potential value of novel fp-VCT with conventional multidetector CT (MDCT) based on a sheep sinus floor elevation model. Calcium-hydroxyapatite reinforced collagen scaffolds were populated with autologous osteoblasts and implanted into sheep maxillary sinus. After 8, 16 and 24 weeks MDCT and fp-VCT scans were performed to investigate the volume of the augmented area; densities of cancellous and compact bone were assessed as comparative values. fp-VCT imaging resulted in higher spatial resolution, which was advantageous when separating closely related anatomical structures (i.e. trabecular and compact bone, biomaterials). Fp-VCT facilitated imaging of alterations occurring in test specimens over time. fp-VCTs therefore displayed high volume coverage, dynamic imaging potential and superior performance when investigating superfine bone structures and bone remodelling of biomaterials. Thus, fp-VCTs may be a suitable instrument for intraoperative imaging and future in vivo tissue-engineering studies.

  20. Challenges of ecological restoration

    DEFF Research Database (Denmark)

    Halme, Panu; Allen, Katherine A.; Aunins, Ainars

    2013-01-01

    on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiversity with increasing intensity. The ecology and biodiversity of boreal forests are relatively well understood making them a good model for restoration activities in many other forest ecosystems. Here......The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many...... ecosystem services remain at high level. However, extensive areas of northern forests are heavily exploited and have lost a major part of their biodiversity value. There is a strong requirement to restore these areas towards a more natural condition in order to meet the targets of the Convention...

  1. The effect of short fiber composite base on microleakage and load-bearing capacity of posterior restorations

    Science.gov (United States)

    Garoushi, Sufyan K.; Hatem, Marwa; Lassila, Lippo V. J.; Vallittu, Pekka K.

    2015-01-01

    Abstract Objectives: To determine the marginal microleakage of Class II restorations made with different composite base materials and the static load-bearing capacity of direct composite onlay restorations. Methods: Class II cavities were prepared in 40 extracted molars. They were divided into five groups (n = 8/group) depending on composite base material used (everX Posterior, SDR, Tetric EvoFlow). After Class II restorations were completed, specimens were sectioned mid-sagitally. For each group, sectioned restorations were immersed in dye. Specimens were viewed under a stereo-microscope and the percentage of cavity leakage was calculated. Ten groups of onlay restorations were fabricated (n = 8/group); groups were made with composite base materials (everX Posterior, SDR, Tetric EvoFlow, Gradia Direct LoFlo) and covered by 1 mm layer of conventional (Tetric N-Ceram) or bulk fill (Tetric EvoCeram Bulk Fill) composites. Groups made only from conventional, bulk fill and short fiber composites were used as control. Specimens were statically loaded until fracture. Data were analyzed using ANOVA (p = 0.05). Results: Microleakage of restorations made of plain conventional composite or short fiber composite base material showed statistically (p onlay restorations made from short fiber-reinforced composite (FRC) as base or plain restoration had statistically significant higher load-bearing capacity (1593 N) (p < 0.05) than other restorations. Conclusion: Restorations combining base of short FRC and surface layer of conventional composite displayed promising performance related to microleakage and load-bearing capacity. PMID:28642894

  2. Comparison of marginal adaptation of mineral trioxide aggregate, glass ionomer cement and intermediate restorative material as root-end filling materials, using scanning electron microscope: An in vitro study.

    Science.gov (United States)

    Gundam, Sirisha; Patil, Jayaprakash; Venigalla, Bhuvan Shome; Yadanaparti, Sravanthi; Maddu, Radhika; Gurram, Sindhura Reddy

    2014-11-01

    The present study compares the marginal adaption of Mineral Trioxide Aggregate (MTA), Glass Ionomer Cement (GIC) and Intermediate Restorative Material (IRM) as root-end filling materials in extracted human teeth using Scanning Electron Microscope (SEM). Thirty single rooted human teeth were obturated with Gutta-percha after cleaning and shaping. Apical 3 mm of roots were resected and retrofilled with MTA, GIC and IRM. One millimeter transverse section of the retrofilled area was used to study the marginal adaptation of the restorative material with the dentin. Mounted specimens were examined using SEM at approximately 15 Kv and 10(-6) Torr under high vacuum condition. At 2000 X magnification, the gap size at the material-tooth interface was recorded at 2 points in microns. One way ANOVA Analysis of the data from the experimental group was carried out with gap size as the dependent variable, and material as independent variable. The lowest mean value of gap size was recorded in MTA group (0.722 ± 0.438 μm) and the largest mean gap in GIC group (1.778 ± 0.697 μm). MTA showed least gap size when compared to IRM and GIC suggesting a better marginal adaptation.

  3. Characterization of materials and alteration-degradation products of the Blessed Virgin Rosary altar in the Saint Dominic church in Ravenna: preliminary study for the restoration interventions

    Directory of Open Access Journals (Sweden)

    Cesare Fiori

    2003-02-01

    Full Text Available The construction of the Blessed Virgin Rosary altar in the Saint Dominic church (13th century in Ravenna occurred between 1723 and 1770. All the portions of the church are interested by intense degradation phenomena and, in particular, the altar preservation condition is worrying. The whole surface is covered by spots and deposits of various nature, efflorescences, swellings, detachments and lacunae. The main cause of damage is the humidity capillary climb. In a preliminary investigation, surveys and observations have been made in order to describe the materials and to evaluate the preservation condition. Then, the areas for sampling have been chosen for analyses and stratigraphies. The present work concerns the altar materials characterisation and the alteration – degradation products analyses: this is essential to plan the restoration interventions.

  4. Comparative evaluation of microleakage in conventional glass ionomer cements and triclosan incorporated glass ionomer cements

    Directory of Open Access Journals (Sweden)

    Rani Somani

    2014-01-01

    Full Text Available Aim and Objective: The aim of the following study is to comparatively evaluate the microleakage of triclosan incorporated GIC with conventional restorative GIC. Materials and Methods: Triclosan in powder form was added to conventional GIC to formulate a concentration of 2.5%. Class five cavities were prepared in non-carious extracted molars and were respectively restored with conventional restorative GIC and triclosan incorporated GIC. Samples were kept in 10% methylene blue dye. Ground sections were obtained and were observed under a binocular microscope for dye penetration. Result: No significant difference was found in the microleakage of two groups. Conclusion: Triclosan incorporated GIC can be considered as an alternative to GIC with enhanced antibacterial property.

  5. Numerical analysis of the effects of non-conventional laser beam geometries during laser melting of metallic materials

    Science.gov (United States)

    Safdar, Shakeel; Li, Lin; Sheikh, M. A.

    2007-01-01

    Laser melting is an important industrial activity encountered in a variety of laser manufacturing processes, e.g. selective laser melting, welding, brazing, soldering, glazing, surface alloying, cladding etc. The majority of these processes are carried out by using either circular or rectangular beams. At present, the melt pool characteristics such as melt pool geometry, thermal gradients and cooling rate are controlled by the variation of laser power, spot size or scanning speed. However, the variations in these parameters are often limited by other processing conditions. Although different laser beam modes and intensity distributions have been studied to improve the process, no other laser beam geometries have been investigated. The effect of laser beam geometry on the laser melting process has received very little attention. This paper presents an investigation of the effects of different beam geometries including circular, rectangular and diamond shapes on laser melting of metallic materials. The finite volume method has been used to simulate the transient effects of a moving beam for laser melting of mild steel (EN-43A) taking into account Marangoni and buoyancy convection. The temperature distribution, melt pool geometry, fluid flow velocities and heating/cooling rates have been calculated. Some of the results have been compared with the experimental data.

  6. To Analyse the Erosive Potential of Commercially Available Drinks on Dental Enamel and Various Tooth Coloured Restorative Materials – An In-vitro Study

    Science.gov (United States)

    Jindal, Ritu; Mahajan, Sandeep; Sandhu, Sanam; Sharma, Sunila; Kaur, Rajwinder

    2016-01-01

    Introduction With the enormous change in life style pattern of a common man through the past few decades, there has been proportional variation in the amount and frequency of consumption of drinks. An increased consumption of these drinks will concurrently increase enamel surface roughness by demineralization, resulting in hypersensitivity and elevated caries risk. Aim The present study was designed to evaluate the erosive potential of commercially available drinks on tooth enamel and various tooth coloured restorative materials. Materials and Methods Extracted human teeth were taken and divided into four groups i.e. tooth enamel, glass ionomer cement, composite and compomer. Four commercially available drinks were chosen these were Coca -Cola, Nimbooz, Frooti and Yakult. The pH of each drink was measured. Each group was immersed in various experimental drinks for a period of 14 days. The erosive potential of each drink was measured by calculating the change in average surface roughness of these groups after the immersion protocol in various drinks. The data analysis was done by One Way Anova, Post-Hoc Bonferroni, and paired t –test. Results Group II-GIC showed highest values for mean of change in average surface roughness and the values were statistically significant (penamel, composite and compomer (p=0.002). Coca-cola showed the highest erosive potential and Yakult showed the lowest, there was no statistical significant difference between the results shown by Yakult and Frooti. Conclusion Characteristics which may promote erosion of enamel and tooth coloured restorative materials were surface texture of the material and pH of the drinks. PMID:27437343

  7. 全瓷修复材料的老化性研究%Research on the Aging of All-ceramics Restoration Materials

    Institute of Scientific and Technical Information of China (English)

    张东姣

    2011-01-01

    全瓷修复材料以良好的美学特性、生物相容性和机械性能在临床上得到了广泛的应用,但全瓷冠桥在复杂的口腔环境下常出现老化现象,致使全瓷材料的颜色及机械性能产生变化.研究全瓷材料的老化现象及其规律可为临床全瓷冠桥的可靠性和耐久性评价及其改进提供有效的理论依据.本文就全瓷材料的老化现象对其颜色和机械性能的影响及影响老化的因素作一综述和评价.%All-ceramic crowns and bridges have been widely used for dental restorations owing to their excellent func-tionalityt aesthetics and biocompatibility. However, the premature clinical failure of all-ceramic crowns and bridges may easily occur when they are subjected to the complex environment of oral cavity. In the oral environment, all-ceramic materials are prone to aging. Aging can lead all-ceramic materials to change color, to lower bending strength, and to reduce anti-fracture toughness. There are many factors affecting the aging of the all-ceramic materials, for example, the grain size, the type of stabilizer, the residual stress and the water environment. In order to analyze the aging behavior, to optimize the design of all-ceramic crowns and bridges, and to evaluate the reliability and durability, we review in this paper recent research progress of aging behavior for all-ceramics restoration materials.

  8. The effect of flowable materials on the microleakage of Class II composite restorations that extend apical to the cemento-enamel junction.

    Science.gov (United States)

    Sadeghi, Mostafa; Lynch, Christopher D

    2009-01-01

    This in vitro study investigated the effects of a thin layer of flowable composite or compomer on microleakage occurring in Class II packable and nanofilled composite restorations that extend apical to the cemento-enamel junction (CEJ). The current study also investigated any differences in microleakage that occur between restorations light-cured using a light-emitting diode (LED) and a quartz tungsten halogen (QTH) light-curing unit. Standardized Class II "slot" cavity preparations were prepared on the mesial and distal surfaces of 72 extracted, unrestored, non-carious premolars (n = 144). The gingival margins were placed 1 mm apical to the CEJ. The teeth were divided into two groups (n = 72) and restored with a "packable composite" (Filtek P60) or a "nano-filled composite" (Universal Filtek Supreme XT) with or without flowable composite (Flowable Filtek Supreme XT) or flowable composite (Dyract Flow) as gingival liners placed with thicknesses of 1.0 mm. Each increment was cured for 20 seconds before adding the next. One-half of the samples in each group was cured with QTH (Coltolux 75) and the other half with LED (Coltolux LED) LCUs. After a two-week incubation period at 37 degrees C, the specimens were thermocycled (5 degrees C-55 degrees C x 1500), immersed in 0.5% basic fuchsin dye for 24 hours, sectioned and the microleakage was then evaluated at the gingival margin by two examiners using a 0-3 score scale. Within the current study, when flowable liners were used, both the packable (Filtek P60) and nanofilled (Filtek Supreme XT Universal Restorative) composite materials had significantly less microleakage than when flowable liners were not used (p flowable liners (Flowable Filtek Supreme XT and Dyract Flow) resulted in a significant reduction of the microleakage occurring under both types of composite materials at the gingival floors ( p < 0.05), but there was no significant difference between them. The choice of light curing technology (LED vs QTH) had no

  9. Restoring primary anterior teeth.

    Science.gov (United States)

    Waggoner, William F

    2002-01-01

    A variety of esthetic restorative materials are available for restoring primary incisors. Knowledge of the specific strengths, weakness, and properties of each material will enhance the clinician's ability to make the best choice of selection for each individual situation. Intracoronal restorations of primary teeth may utilize resin composites, glass ionomer cements, resin-modified ionomers, or polyacid-modified resins. Each has distinct advantages and disadvantages and the clinical conditions of placement may be a strong determining factor as to which material is utilized. Full coronal restoration of primary incisors may be indicated for a number of reasons. Crowns available for restoration of primary incisors include those that are directly bonded onto the tooth, which generally are a resin material, and those crowns that are luted onto the tooth and are some type of stainless steel crown. However, due to lack of supporting clinical data, none of the crowns can be said to be superior to the others under all circumstances. Though caries in the mandibular region is rare, restorative solutions for mandibular incisors are needed. Neither stainless steel crowns nor celluloid crown forms are made specifically for mandibular incisors. Many options exist to repair carious primary incisors, but there is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. This does not discount the fact that dentists have been using many of these crowns for years with much success. Operator preferences, esthetic demands by parents, the child's behavior, and moisture and hemorrhage control are all variables which affect the decision and ultimate outcome of whatever restorative treatment is chosen.

  10. Fire victim identification by post-mortem dental CT: Radiologic evaluation of restorative materials after exposure to high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Woisetschlaeger, Mischa, E-mail: Mischa.woisetschlager@lio.se [Center for Medical Image Science and Visualisation (CMIV), University Hospital Linkoeping, Linkoeping University, 58185 Linkoeping (Sweden); Lussi, Adrian, E-mail: anders.persson@cmiv.lio.se [Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010 Bern (Switzerland); Persson, Anders, E-mail: adrian.lussi@zmk.unibe.ch [Center for Medical Image Science and Visualisation (CMIV), University Hospital Linkoeping, Linkoeping University, 58185 Linkoeping (Sweden); Jackowski, Christian, E-mail: christian.jackowski@irm.uzh.ch [Center for Medical Image Science and Visualisation (CMIV), University Hospital Linkoeping, Linkoeping University, 58185 Linkoeping (Sweden); Institute of Legal Medicine, University of Zuerich, Winterthurerstrasse 190/52, 8057 Zuerich (Switzerland)

    2011-11-15

    Objectives: The aim of this study was to evaluate the use of high resolution CT to radiologically define teeth filling material properties in terms of Hounsfield units after high temperature exposure. Methods: 122 human molars with 10 different filling materials at defined filling diameters were examined. The teeth were CT scanned both before and after the exposure to different temperatures. After image reconstruction, the teeth and filling materials were analyzed regarding their morphology and Hounsfield units (HU) using an extended HU scale. Results: The majority of filling materials diminished in size at temperatures {>=}400 deg. C. HU values were stable for all materials up till 200 deg. C, and only slightly changed up to 600 deg. C. Cerec, Dyract and dentin showed only minor changes in HU at all temperatures. The other materials, inclusive enamel, showed specific patterns, either increasing or decreasing in HU with increasing temperatures over 600 deg. C. Conclusions: Over 600 deg. C the filling materials show specific patterns that can be used to discriminate filling materials. Ultra high resolution CT may improve the identification processes in fire victims. Existing 3D visualization presets for the dentition can be used until 600 deg. C and have to be optimized for bodies exposed to higher temperatures.

  11. Beyond Conventional Cathode Materials for Lithium-ion Batteries and Sodium-ion Batteries Nickel fluoride conversion materials and P2 type Sodium-ion intercalation cathodes

    Science.gov (United States)

    Lee, Dae Hoe

    The Li-ion battery is one of the most important rechargeable energy storage devices due to its high energy density, long cycle life, and reliable safety. Although the performances of Li-ion batteries have been improved dramatically, the limit in terms of the energy density still needs to be resolved to meet the growing demands for large-scale mobile devices. Choosing the cathode material is the most pivotal issue in achieving higher energy, since the energy density is directly correlated to the specific capacity of the cathode. Intercalation-based cathode materials have been widely utilized in commercial products; however they yield a limited capacity due to restricted crystallographic sites for Li-ions. In this thesis, the NiF2 and NiO doped NiF2/C conversion materials, which display substantially greater capacities, are intensively studied using various synchrotron X-ray techniques and magnetic measurements. The enhanced electronic conductivity of NiO doped NiF2/C is associated with a significant improvement in the reversible conversion reaction. While bimodal Ni nanoparticles are maintained for NiO doped NiF2/C upon the discharge, for pure NiF2 only smaller nanoparticles remain following the 2nd discharge. Based on the electronic conductivity, it is demonstrated that the size of Ni nanoparticles is associated with the conversion kinetics and consequently the reversibility. Although Li-ion batteries offer the highest energy density among all the secondary batteries, the amount of the reserves and the cost associated with the Li sources are still a concern. In the second part of the thesis, P2 type Na2/3[Ni1/3Mn2/3]O2 is investigated to understand the structural stability in the Na-ion batteries. Significantly improved battery performances are obtained by excluding the phase transformation region. In addition, the structural evolution of the P2-Na0.8[Li0.12Ni0.22Mn0.66]O 2 is tracked by in situ technique and revealed no phase transformation during the cycling. It

  12. Microleakage resistance of minimally invasive Class I flowable composite restorations.

    Science.gov (United States)

    Bonilla, Esteban D; Stevenson, Richard G; Caputo, Angelo A; White, Shane N

    2012-01-01

    Minimally invasive flowable composite Class I restorations are widely used. However, flowable composites are characterized by low filler contents, modified resin formulations, low moduli of elasticity, low viscosity, generally poor mechanical properties, and decreased long-term stability. The purpose of this study was to compare the microleakage resistance of a wide variety of flowable composites used with their manufacturers' recommended bonding systems to that of a long-used and widely studied microhybrid composite when placed as minimally invasive occlusal restorations. Molar teeth were prepared in a standardized manner, restored, artificially aged, stained, sectioned, evaluated, and analyzed. Microleakage varied substantially, by a whole order of magnitude, among the material groups tested. The control group, a conventional microhybrid composite material, leaked significantly less than all the flowable composite groups. Microleakage varied very slightly among measurement site locations. Tiny microscopic bubbles were seen within many of the flowable composite specimens, as were a few voids.

  13. In vitro evaluation of topical fluoride pH and their effect on surface hardness of composite resin-based restorative materials.

    Science.gov (United States)

    Mujeeb, Abdul; Mansuri, Samir; Hussain, Seema Abid; Ramaswamy, Kausar

    2014-03-01

    The aim of the study was to correlate the pH and fluoride ion uptake with surface hardness of composite resin based restorative materials after topical fluoride application. Forty disks of each of test materials Composite (Filtek Z350XT, 3M ESPE, St Paul, MN, USA), Resin modified glass ionomer (Vitremer) and Compomer (Dyract AP) were made and ten disks of each material were placed in different test solutions - 1.23% APF gel, Sodium fluoride mouth rinse, 0.9% neutral fluoride and distilled water (Control group). After 36 hours of immersion, specimens were subjected to microhardness testing machine for evaluation of surface hardness. The greater hardness deterioration for all materials resulted with 1.23% APF gel when compared to the control group. Composite (Filtek Z350XT, 3M ESPE, St Paul, MN, USA) showed 17.13 VHN (control group 59.11 VHN). Vitremer showed 9.71 VHN (control group 37.71 VHN). Compomer showed 19.22 VHN (control group 36.78 VHN). 1.23% ApF gel significantly decreased hardness of composite, Vitremer and Compomer. Hardness deterioration associated with sodium fluoride mouth rinse and 0.9% neutral fluoride was less compared to 1.23% ApF gel.

  14. Experimental Investigation of Effect of Process Parameters on Mrr and Surface Roughness In Turning Operation on Conventional Lathe Machine For Aluminum 6082 Grade Material Using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Mihir T. Patel

    2014-01-01

    Full Text Available In this study, the effect of the machining parameters like spindle speed, feed, depth of cut and nose radius on material removal rate and surface roughness are investigated, also optimum process parameters are studied. An L8 orthogonal array (mixed level design, analysis of variance (ANOVA and the signal –to-noise (S/N ratio are used in this study. Mixed levels of machining parameters are used and experiments are done on conventional lathe machine. Aluminum Alloy - Al 6082 grade material is used in high stress applications, Trusses, Bridges, Cranes, Transport applications, Ore skips, Beer barrels, Milk churns etc. The most significant parameters for material removal rate are speed, depth of cut and least significant factor for MRR is nose radius For surface roughness speed, nose radius are the most significant parameters and least significant factor for surface roughness is depth of cut. The mathematical model obtained as a result of regression analysis can be reliable to predict MRR and surface roughness Ra.

  15. Application of Dredged Materials and Steelmaking Slag as Basal Media to Restore and Create Seagrass Beds: Mesocosm and Core Incubation Experiments

    Science.gov (United States)

    Tsukasaki, A.; Suzumura, M.; Tsurushima, N.; Nakazato, T.; Huang, Y.; Tanimoto, T.; Yamada, N.; Nishijima, W.

    2016-02-01

    Seagrass beds stabilize bottom sediments, improve water quality and light conditions, enhance species diversity, and provide habitat complexity in coastal marine environments. Seagrass beds are now experiencing worldwide decline by rapid environmental changes. Possible options of seagrass bed restoration are civil engineering works including mounding to raise the bottom to elevations with suitable light for seagrass growth. Reuse or recycling of dredged materials (DM) and various industrial by-products including steelmaking slags is a beneficial option to restore and create seagrass beds. To evaluate the applicability of DM and dephosphorization slag (Slag) as basal media of seagrass beds, we carried out mesocosm experiments and core incubation experiments in a land-based flow-through seawater tank over a year. During the mesocosm experiment, no difference was found in growth of eelgrass (Zostera marina L.) and macrobenthic community structures between Slag-based sediments and sand-based control experiments, even though Slag-based sediments exhibited substantially higher pH than sand-based sediments. During the core incubation experiment, we investigated detailed variation and distributions of pH and nutrients, and diffusion fluxes of nutrients between the sediment/seawater interface. Though addition of Slag induced high pH up to 10.7 in deep layers (reported in natural coastal systems. It was suggested that the mixture of Slag and DM is applicable as basal media for construction of artificial seagrass beds.

  16. Self-healing efficiency of cementitious materials containing microcapsules filled with healing adhesive: mechanical restoration and healing process monitored by water absorption.

    Science.gov (United States)

    Li, Wenting; Jiang, Zhengwu; Yang, Zhenghong; Zhao, Nan; Yuan, Weizhong

    2013-01-01

    Autonomous crack healing of cementitious composite, a construction material that is susceptible to cracking, is of great significance to improve the serviceability and to prolong the longevity of concrete structures. In this study, the St-DVB microcapsules enclosing epoxy resins as the adhesive agent were embedded in cement paste to achieve self-healing capability. The self-healing efficiency was firstly assessed by mechanical restoration of the damaging specimens after being matured. The flexural and compressive configurations were both used to stimulate the localized and distributed cracks respectively. The effects of some factors, including the content of microcapsules, the curing conditions and the degree of damage on the healing efficiency were investigated. Water absorption was innovatively proposed to monitor and characterize the evolution of crack networks during the healing process. The healing cracks were observed by SEM-EDS following. The results demonstrated that the capsule-containing cement paste can achieve the various mechanical restorations depending on the curing condition and the degree of damage. But the voids generated by the surfactants compromised the strength. Though no noticeable improved stiffness obtained, the increasing fracture energy was seen particularly for the specimen acquiring 60% pre-damage. The sorptivity and amount of water decreased with cracks healing by the adhesive, which contributed to cut off and block ingress of water. The micrographs by SEM-EDS also validated that the cracks were bridged by the hardened epoxy as the dominated elements of C and O accounted for 95% by mass in the nearby cracks.

  17. Effect of high-pressure/temperature (HP/T) treatments of in-package food on additive migration from conventional and bio-sourced materials.

    Science.gov (United States)

    Mauricio-Iglesias, M; Jansana, S; Peyron, S; Gontard, N; Guillard, V

    2010-01-01

    Migration was assessed during and after two high-pressure/temperature (HP/T) treatments intended for a pasteurization (800 MPa for 5 min, from 20 to 40 degrees C) and a sterilization treatment (800 MPa for 5 min, from 90 to 115 degrees C) and were compared with conventional pasteurization and sterilization, respectively. The specific migration of actual packaging additives used as antioxidants and ultraviolet light absorbers (Irganox 1076, Uvitex OB) was investigated in a number of food-packaging systems combining one synthetic common packaging (LLDPE) and a bio-sourced one (PLA) in contact with the four food-simulating liquids defined by European Commission regulations. After standard HP/T processing, migration kinetics was followed during the service life of the packaging material using Fourier transform infrared spectrometer (FTIR) spectroscopy. LLDPE withstood the high-pressure sterilization, whereas it melted during the conventional sterilization. No difference was observed on migration from LLDPE for both treatments. In the case of PLA, migration of Uvitex OB was very low or not detectable for all the cases studied.

  18. Microwave-assisted versus conventional decomposition procedures applied to a ceramic potsherd standard reference material by inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulou, D.N.; Zachariadis, G.A.; Anthemidis, A.N.; Tsirliganis, N.C.; Stratis, J.A

    2004-03-03

    Inductively coupled plasma atomic emission spectrometry (ICP-AES) is a powerful, sensitive analytical technique with numerous applications in chemical characterization including that of ancient pottery, mainly due to its multi-element character, and the relatively short time required for the analysis. A critical step in characterization studies of ancient pottery is the selection of a suitable decomposition procedure for the ceramic matrix. The current work presents the results of a comparative study of six decomposition procedures applied on a standard ceramic potsherd reference material, SARM 69. The investigated decomposition procedures included three microwave-assisted decomposition procedures, one wet decomposition (WD) procedure by conventional heating, one combined microwave-assisted and conventional heating WD procedure, and one fusion procedure.