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Sample records for class-v composite restorations

  1. A Comparative Evaluation of Microleakage in Class V Composite Restorations

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    Sujatha Gopal Sooraparaju

    2014-01-01

    Full Text Available Aim. To compare and evaluate the microleakage in class V lesions restored with composite resin with and without liner and injectable nanohybrid composite resin. Materials and Methodology. 60 class V cavities were prepared in 30 freshly extracted teeth. After etching and application of bonding agents these cavities were divided into three groups: Group A (n=20—restored with composite resin, Group B (n=20—flowable composite resin liner + composite resin, and Group C (n=20—restored with injectable composite resin. After curing all the specimens were subjected to thermocycling and cyclic loading. Specimens were stained with 0.5% basic fuchsin and evaluated for dye penetration. Results. Results are subjected to Kruskal Wallis and Wilcoxon test. Conclusion. Within the limitations of this study, none of the three materials were free from microleakage. All the three materials showed more microleakage at gingival margins compared to occlusal margins. Among all the groups G-ænial Flo showed the least microleakage at the gingival wall.

  2. Marginal microleakage of class V composite restorations before and after AFP gel application

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    Davari Abdolrahim

    2015-01-01

    Full Text Available   Background and Aims: The most effective preventing tooth decay method is fluoride compounds applications. Some studies suggested that APF gels caused changes on the superficial physical properties of composite. Therefore, the purpose of this study was to evaluate the marginal microleakage of class V composite restorations before and after AFP gel application.   Materials and Methods: The class V cavities in buccal surfaces of 45 molar teeth were made in such a way that occlusal margin was placed in enamel and cervical margin in cement. In group 1, at first fluoride-therapy and then cavity preparation and restoration by composite resin was done. In group 2, at first the class V cavities were prepared and restored, then fluoride-therapy was carried out. In group 3, cavities were prepared and restored with no fluoride-therapy. The dye penetration rate in occlusal and cervical margins was examined by stereomicroscope. Data were statistically analyzed using Kruskal-Wallis and Mann-Whitney test.   Results: There was no statistically significant difference between groups ( P=0.975.   Conclusion: Fluoride-therapy using AFP gel before and after class V composite restorations, had no significant effect on the microleakage of dentin and enamel margins.

  3. Microleakage of silorane- and methacrylate-based class V composite restorations.

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    Krifka, Stephanie; Federlin, Marianne; Hiller, Karl-Anton; Schmalz, Gottfried

    2012-08-01

    The marginal integrity of class V restorations in a silorane- and a group of methacrylate-based composite resins with varying viscosities was tested in the present study. Different adhesives (OptiBond FL, KerrHawe; AdheSE One, Vivadent; or Silorane System Adhesive, 3M ESPE) were applied to 168 standardized class V cavities. The cavities (n = 12) were filled with a wide range of different viscous composite resins: Filtek Silorane, 3M ESPE; els and els flow, Saremco; Tetric EvoCeram and Tetric EvoFlow, Vivadent; Grandio, Voco; and Ultraseal XT Plus, Ultradent. Microleakage of the restoration was assessed by dye penetration (silver staining) on multiple sections with and without thermocycling and mechanical loading (TCML: 5,000 × 5-55°C; 30 s/cycle; 500,000 × 72.5 N, 1.6 Hz). Data were statistically analyzed with the Mann-Whitney U test and the Error Rates Method (ERM). The silorane-based composite resin yielded the lowest dye penetration after TCML. Microleakage of methacrylate-based composite restorations, in general (ERM), was statistically significantly influenced by the adhesive system, Moreover, dye penetration at enamel margins was significantly lower than dye penetration at dentin margins. The chemical basis of composite resins and adjacent tooth substance seems to strongly influence marginal sealing of class V restorations for methacrylate-based materials. Moreover, the steps of dental adhesives used affected marginal integrity. The silorane-based composite resin evaluated in the present study exhibits the best marginal seal. The three-step adhesive yielded better marginal sealing than the one-step adhesive for methacrylate-based class V composite restorations. PMID:21947906

  4. Effect of Different Placement Techniques on Microleakage of Class V Composite Restorations

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    M. Moezyzadeh

    2009-09-01

    Full Text Available Objective: Various techniques of composite placement have been used to decrease microleakage around the composite restorations. Due to controversial results, the present study was conducted to investigate the effect of different placement techniques on microleakage in class V composite restorations.Materials and Methods: Sixty class V cavities were prepared on the buccal and lingual surfaces of 30 extracted healthy human premolars. The teeth were randomly assigned to five groups, and were restored with composite resin, using five different techniques:(1 horizontal increments (gingivo-occlusal, (2 horizontal increments (occluso-gingival,(3 oblique increments (gingivo-occlusal, (4 oblique increments (occluso-gingival, and(5 bulk placement. After thermocycling, 500 cycles of between 5°C and 55°C (SD=2,and immersion in 0.5% alcoholic Fuschin, the teeth were then sectioned and evaluated for microleakage by stereomicroscope (×16. Microleakage was scored on a 0-4 scale. Nonparametric Mann-Whitney U and Kruskal-Wallis tests served for statistical analysis.Results: Gingival margins of class V cavities showed microleakage regardless of the placement technique. Oblique (gingivo-occlusal technique showed less microleakage in gingival margins of the restorations compared to bulk technique. The least microleakagein gingival margins was related to group 3 while the most microleakage was related to group 5. Bulk and oblique (gingivo-occlusal incremental techniques produced significantlydifferent rate of microleakage (P<0.003. Group 3 showed the most difference with groups 5, 1, 2, and 4, respectively.Conclusion: Among four incremental techniques, the gingivo-occlusal oblique filling technique resulted in a lower leakage value, when compared to the bulk filling technique.

  5. Effect of three surface sealants on marginal sealing of Class V composite resin restorations.

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    Ramos, R P; Chimello, D T; Chinelatti, M A; Dibb, R G; Mondelli, J

    2000-01-01

    This study evaluated in vitro the effectiveness of three different surface sealants (Fortify, Protect-it! and Optiguard) on the marginal sealing of Class V light-activated composite resin restorations (Prodigy). For this purpose, 20 sound noncarious human premolars extracted within a six-month period were selected. Class V cavities with the occlusal margin in enamel and cervical margin in cementum were prepared in both buccal and lingual surfaces. The teeth, randomly assigned in four groups with 10 cavities in each group, were restored with composite resin after applying an adhesive system (Optibond FL). After the finishing and polishing procedures, the restorations were covered with a specific surface sealant, except for the control samples, which were not sealed. After placing restorations, the specimens were thermocycled and immersed in a 50% silver nitrate solution (tracer agent) for eight hours, sectioned longitudinally and analyzed for leakage using an optical microscope in a blind study with three examiners. The marginal microleakage was evaluated at the occlusal and cervical interfaces and compared among the four groups using the Kruskall-Wallis and the Wilcoxon Tests. There was better sealing at the occlusal margin, and in this region, there were no statistically significant differences among the materials (p > 0.05). In the cervical region, Fortify and Protect-it! showed improved results over the Control Group, and Optiguard showed similar results to the Control Group (without sealing). PMID:11203855

  6. Microleakage of Dual-Cured Adhesive Systems in Class V Composite Resin Restorations

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    S Kasraie

    2012-01-01

    Full Text Available Objective: Microleakage is a major factor affecting longevity of composite restorations. This study evaluated the effect of polymerization mode of bonding agent on microleakage of composite restorations.Materials and Methods: Forty-eight Class V cavities were prepared on buccal and lingual surfaces of 24 extracted human premolars. Occlusal and gingival margins were placed in the enamel and dentin, respectively. Teeth were divided into four groups as follows: Group I: Optibond Solo Plus (light-cured; Group II: Optibond Solo Plus (dual-cured; Group III: Prime & Bond NT (light-cured, Group IV: Prime & Bond NT (dual-cured. Teeth were restored using Z250 composite in three increments. After polishing the restorations, samples were thermocycled for 1000 cycles and stored in distilled water for 3 months. Then they were placed in 2% fuchsine solution for 48 hours. The samples were sectioned longitudinally and evaluated for microleakage under a stereomicroscope at ×40magnification. Dye penetration was scored on a 0-3 ordinal scale. Data were analyzed using Kruskal-Wallis, Bonferroni and Wilcoxon signed ranks test.Results: Microleakage was significantly lower in enamel margins compared to dentin margins (P0.05. Prime & Bond NT had less microleakage compared to Optibond SoloPlus, but the difference was not significant (P>0.05.Conclusion: There was no difference in the amount of microleakage in Class V composite restorations using light-cured and dual-cured bonding systems. Dentinal margins of restorations exhibited more microleakage than enamel margins.

  7. Effect of Two Surface Sealants on Microleakage of Class V Resin Composite Restorations

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    Mosa Aboali

    2012-02-01

    Full Text Available Background and Aims: When composite resin polymerizes, shrinkage stresses tend to produce gaps at the tooth/ restoration interfaces. Surface sealants may reduce or avoid problems related to the marginal interface. The aim of this study was to evaluate the effect of two different surface sealants (Fortify and Optiguard on the microleakage of class V resin composite restorations. Materials and Methods: Twenty three sound noncarious molars were collected. Totally, 45 Class V cavities with the occlusal margins in enamel and cervical margins in cementum were prepared in both buccal and lingual surfaces. The specimens were randomly assigned in three groups (15 cavities in each group and then restored with a resin composite. After the finishing and polishing procedures, the restorations in each group were covered with a specific surface sealant, except for the control samples, which were not sealed. After placing restorations, the specimens were thermocycled and then immersed in a 50% silver nitrate solution (tracer agent for four hours, sectioned longitudinally and analyzed for leakage using a stereomicroscope in a blind manner. The marginal microleakage was evaluated at the occlusal and cervical interfaces and compared among the three groups using the Kruskall-Wallis and the Mann-Whitney U tests. Results: Microleakage was found in all groups at both occlusal and cervical margins. Significantly greater leakage was observed at the cervical margins compared to the enamel margins of the material groups (P=0.005. There was no statistically significant difference among the groups at occlusal margins (P=0.66. In the cervical region, Fortify showed improved results and statistically presented the lowest degree of microleakage (P=0.003. onclusion: The used sealant materials presented different rates of effectiveness and Fortify decreased marginal microleakage significantly.

  8. Effect of surface roughness of cavity preparations on the microleakage of Class V resin composite restorations.

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    Shook, Larry W; Turner, Edgar W; Ross, Judith; Scarbecz, Mark

    2003-01-01

    This study determined whether surface roughness of the internal walls of a Class V resin composite preparation, using a carbide bur, a medium-grit diamond bur and a fine-grit diamond bur, affected the degree of microleakage of the restoration. The facial and lingual surfaces of 45 non-carious extracted human molars provided 90 samples for evaluation. The specimen surfaces were assigned randomly in equal numbers to one of three groups (n = 30). Conservative Class V composite preparations were made using one of three different burs: a 330-carbide bur, a 330 fine-grit diamond bur or a 330 medium-grit diamond bur (Brasseler USA). After acid etching, PQ1 (Ultradent Products Inc) primer/bonding resin and Vitalescence (Ultradent Products Inc) were applied and cured following the manufacturers' instructions. After minor finishing, the apices of all root surfaces were sealed with Vitrebond (3M), and the unprepared external surfaces were sealed with nail polish to within 1 mm of the restoration margins. The specimens were stored in distilled water at room temperature for 24 hours, then subjected to 1,200 thermocycles at 5 degrees C and 55 degrees C with a 30-second dwell time. After cycling, the teeth were immersed in a 5% solution of methylene blue dye for 12 hours. The molars were invested in clear acrylic casting resin, labeled, then sectioned once vertically approximately midway through the facial and lingual surfaces using a diamond coated saw blade. Microleakage was evaluated using a 10x microscope for the enamel and cementum surfaces and blindly scored by two independent examiners. In all cases, regardless of the examiner, at both the enamel and the dentin margins, the analysis revealed no statistically significant differences in microleakage across bur types. Further results show that dentin margins leaked significantly more than enamel margins for all bur types.

  9. Microleakage comparison of three types of adhesive systems versus GIC-based adhesive in class V composite restorations

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    Mostafa Sadeghi

    2016-01-01

    Background and aims: New dentin bonding agents and techniques have been developed to reduce microleakage and create higher bond strength. This in-vitro study compared the microleakage of three resin-based adhesives versus a GIC-based adhesive on class V composite restorations.  Materials and Methods: Class V cavities were prepared on the buccal surfaces of 72 sound premolars, randomly assigned to six groups (n=12) and treated as follows: without any treatment (negative control group); total-e...

  10. Marginal adaptation of class V composite restorations submitted to thermal and mechanical cycling

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    Denise Sa Maia CASSELLI

    2013-01-01

    Full Text Available Objective This study evaluated the effect of the margin location and an adhesive system on the marginal adaptation of composite restorations. Material and Methods Class V cavities were prepared in bovine teeth with the gingival margin on the dentin and the incisal margin on the enamel. The cavities were restored with a micro-hybrid composite resin using an etch-and-rinse [Single Bond 2 (SB] or a self-etching adhesive [Clearfil SE Bond (CL]. After finishing and polishing the restorations, epoxy replicas were prepared. The marginal adaptation was analyzed using scanning electronic microscopy (SEM, 500 x magnification. The higher gap width in each margin was recorded (T0. After the first evaluation, the samples were submitted to thermal cycling (2,000 cycles of 5°C±2°C followed by 55°C±2°C – T1 and mechanical cycling (100,000 cycles of 50 kN and 2 Hz – T2. Replicas of samples were rebuilt after each cycling and analyzed under SEM. The data were submitted to Mann-Whitney, Wilcoxon and Friedman testing (α=0.05. Results The SB presented higher gaps in the dentin than the enamel, while there was no difference between the substrate for the CL. In the dentin, the CL showed better marginal sealing than the SB. The opposite occurred in the enamel. There were no significant differences between the baseline, thermal and mechanical cycling for any experimental condition. Conclusions The outcomes of the present study showed that the adhesive system and margin location have an important effect on the marginal adaptation of composite restorations.

  11. Marginal adaptation of class V composite restorations submitted to thermal and mechanical cycling

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    CASSELLI, Denise Sá Maia; FARIA-E-SILVA, André Luis; CASSELLI, Henrique; MARTINS, Luis Roberto Marcondes

    2013-01-01

    Objective: This study evaluated the effect of the margin location and an adhesive system on the marginal adaptation of composite restorations. Material and Methods: Class V cavities were prepared in bovine teeth with the gingival margin on the dentin and the incisal margin on the enamel. The cavities were restored with a micro-hybrid composite resin using an etch-and-rinse [Single Bond 2 (SB)] or a self-etching adhesive [Clearfil SE Bond (CL)]. After finishing and polishing the restorations, epoxy replicas were prepared. The marginal adaptation was analyzed using scanning electronic microscopy (SEM, 500 x magnification). The higher gap width in each margin was recorded (T0). After the first evaluation, the samples were submitted to thermal cycling (2,000 cycles of 5ºC±2ºC followed by 55ºC±2ºC - T1) and mechanical cycling (100,000 cycles of 50 kN and 2 Hz - T2). Replicas of samples were rebuilt after each cycling and analyzed under SEM. The data were submitted to Mann-Whitney, Wilcoxon and Friedman testing (a=0.05). Results: The SB presented higher gaps in the dentin than the enamel, while there was no difference between the substrate for the CL. In the dentin, the CL showed better marginal sealing than the SB. The opposite occurred in the enamel. There were no significant differences between the baseline, thermal and mechanical cycling for any experimental condition. Conclusions: The outcomes of the present study showed that the adhesive system and margin location have an important effect on the marginal adaptation of composite restorations. PMID:23559115

  12. Evaluation of internal adaptation of Class V resin composite restorations using three techniques of polymerization

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    José Carlos Pereira

    2007-02-01

    Full Text Available OBJECTIVE: The purpose of this in vitro study was to evaluate the internal adaptation of Class V composite restorations to the cavity walls using three different techniques of polymerization. METHODS: Standard cavities were prepared on the buccal and lingual surfaces of 24 extracted human third molars with margins located above and below the cementoenamel junction. Restorations were placed in one increment using two restorative systems: 3M Filtek A110/ Single Bond (M and 3M Filtek Z250/ Single Bond (H in the same tooth, randomly in the buccal and lingual surfaces. Resin composites were polymerized using three techniques: Group 1 - Conventional (60 s - 600 mW/cm²; Group 2 - Soft-start (20 s - 200 mW/cm² , 40 s - 600 mW/cm²; Group 3 - Pulse Activation (3 s - 200 mW/cm², 3-min hiatus, 57 s - 600 mW/cm². Buccolingual sections were polished, impressions taken and replicated. Specimens were assessed under scanning electron microscopy up to X1000 magnification. Scores were given for presence or absence of gaps (0 - no gap; 1 - gap in one wall; 2 - gap in two walls; 3 - gap in three walls. RESULTS: The mean scores of the groups were (±SD were: G1M-3.0 (± 0.0; G2M-2.43 (± 0.8; G3M- 1.71 (± 0.9; G1H- 2.14 (± 1.2; G2H- 2.00 (± 0.8; G3H- 1.67 (± 1.1. Data were analyzed using Kruskal-Wallis and Dunnet's tests. No statistically significant difference (p>0.05 was found among groups. Gaps were observed in all groups. CONCLUSIONS: The photocuring technique and the type of resin composite had no influence on the internal adaptation of the material to the cavity walls. A positive effect was observed when the slow polymerization techniques were used.

  13. In vitro Comparison of Microleakage of Nanofilled and Flowable Composites in Restoring Class V Cavities in Primary Molars

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    Rahil Ahmadi

    2013-01-01

    Full Text Available Background: Composite resins undergo microleakage due to polymerization shrinkage particularly when located in cementum or dentin. The purpose of this study was to compare the microleakage of flowable and nanofilled composites in Class V cavities extending on to the root in primary molars. Materials and Methods: Forty eight class V cavities in the cervical part of buccal and lingual surfaces of 24 intact mandibular second primary molars were prepared, with occlusal margins on enamel and gingival margins on cementum. After restoring cavities randomly with nanofilled or flowable composite by incremental technique, specimens were stored in distilled water for 24 hours, thermocycled, immersed in a basic Fuchsin solution for 24 hours and sectioned buccolingually. Microleakage was evaluated according to the depth of dye penetration along the restoration wall using a stereomicroscope. Data were analyzed by Mann- Whitney U test at a significance level of 0.05.Results Microleakage of flowable and nanofilled composites at the cervical margin showed no statistically significant difference, however occlusal margin in nanofilled composite exhibited significantly less microleakage than flowable composite (p=0.013.Conclusion: In contrast to occlusal margin, there was no statistically significant difference in microleakage between the 2 composites on the gingival margin. Microleakage on the gingival wall was greater compared to occlusal wall for both composites.

  14. Marginal sealing of curing contraction gaps in Class V composite resin restorations.

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    Kemp-Scholte, C M; Davidson, C L

    1988-05-01

    When one uses composite resins, the curing contraction, the stiffness of the material, and the strength of the vulnerable dentinal bond are important factors in determining the marginal adaptation of the restoration. Calculations based on these intrinsic material properties have indicated that both bulk placement and incremental placement of the restorative material in the cervical cavity inevitably lead to marginal gap formation. Sealing of this gap with an unfilled low-viscosity resin, directly after the composite resin is cured, may lead to perfectly closed restoration margins, provided that composites with low linear curing contraction and low Young's modulus are used. These conditions were experimentally shown to be valid for laboratory and clinical situations.

  15. Assessing microleakage of composite restorations in class V cavities prepared by Er:YAG laser irradiation or diamond bur

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    Sakineh Arami

    2014-01-01

    Full Text Available Introduction: The aim of this study was to make a comparison between microleakage of conventionally restored class V cavities using bur and acid etchant and, the ones prepared and conditioned by Er:YAG laser. Materials and Methods: 30 recently extracted intact caries and filling free human permanent molars were used for this study. Then, Cold cure acrylic resin was used to seal the apices. The samples were randomly assigned to 5 groups of six each. Class V cavities were prepared one on buccal and one on lingual surface of each sample. Group 1: cavity preparation by diamond bur and turbine + acid etch, Group 2: cavity preparation by Er:YAG laser + acid etch, Group 3: cavity preparation by Er:YAG laser + Laser etching, Group 4: cavity preparation by diamond bur and turbine + laser etching, Group 5: cavity preparation by Er:YAG laser with no conditioning procedure. The cavities restored with restorative composite resin. Samples were then immersed in 2% methylene blue solution for 24 hours. The data were then analyzed using Wilcoxon signed ranks test and Kruskal-Wallis statistical tests. Results: The Kruskal Wallis test showed a significant difference (P < 0.05 between enamel and cementum margin microleakage, while the higher microleakage was related to the cementum margin of restorations. Conclusion: There was no significant difference in evaluating microleakeage degree of cavities prepared by Er:YAG laser and diamond bur.

  16. Sealing of adhesive systems in ferric sulfate-contaminated dentinal margins in class V composite resin restorations

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    Shadman, Niloofar; Farzin Ebrahimi, Shahram; Mollaie, Najmeh

    2016-01-01

    Background. Hemostatic agents are applied to prepare an isolated bleeding-free condition during dental treatments and can influence adhesive restorations. This study evaluated the effect of a hemostatic agent (ViscoStat) on microleakage of contaminated dentinal margin of class V composite resin restorations with three adhesives. Methods. Sixty freshly extracted human molars were selected and class V cavities (3×3×1.5 mm) were prepared on buccal and lingual surfaces. Gingival margins of the cavities were placed below the cementoenamel junction. The teeth were divided into six groups randomly. The adhesives were Excite, AdheSE and AdheSE One. In three groups, the gingival walls of the cavities were contaminated with ViscoStat and then rinsed. The cavities were restored with composite resin and light-cured. After storage in distilled water (37°C) for 24 hours and polishing, the samples were thermocycled and sealed with nail varnish. Then they were stored in 1% basic fuchsin for 24 hours, rinsed and mounted in self-cured acryl resin, followed by sectioning buccolingually. Dye penetration was observed under a stereomicroscope and scored. Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney U tests. Peffects on dentin microleakage (P > 0.05). In the contaminated groups, Excite had significantly less microleakage than the others (P = 0.003). AdheSE and AdheSE One did not exhibit significant difference in microleakage (P > 0.05). Conclusion. ViscoStat hemostatic agent increased dentinal microleakage in AdheSE and AdheSE One adhesives with no effect on Excite. PMID:27092210

  17. Microleakage comparison of three types of adhesive systems versus GIC-based adhesive in class V composite restorations

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    Mostafa Sadeghi

    2016-06-01

    Full Text Available Background and aims: New dentin bonding agents and techniques have been developed to reduce microleakage and create higher bond strength. This in-vitro study compared the microleakage of three resin-based adhesives versus a GIC-based adhesive on class V composite restorations.  Materials and Methods: Class V cavities were prepared on the buccal surfaces of 72 sound premolars, randomly assigned to six groups (n=12 and treated as follows: without any treatment (negative control group; total-etch (OptiBond Solo Plus; two-step self-etch (OptiBond XTR; one-step self-etch (OptiBond All-in-One and GIC-based adhesive (Fuji bond LC with pre-cure and co-cure techniques. The treated cavities were filled with a micro-hybrid resin composite (Point 4, Kerr. Following finishing and polishing procedures, the specimens were placed in 100% humidity, stored in distilled water, thermocycled and then immersed in a methylene blue, sectioned, evaluated for microleakage and scored on a 0 to 3 ordinal scale.  Results: None of the adhesives tested were capable of completely eliminating marginal microleakage. There were statistically significant differences among the test groups at occlusal margins; but at cervical margins were not. The Fuji Bond LC with co-cure and control groups had significantly greater microleakage scores at the occlusal margins. At the cervical margins, the bonded restorations with OptiBond XTR and OptiBond All-in-One adhesives presented significantly lower microleakage scores. Also, there were no significant differences between the resin adhesive groups both at occlusal and cervical margins. The microleakage scores at the cervical margins were markedly higher than the occlusal margins in the groups bonded with OptiBond Solo Plus and Fuji Bond LC with pre-cure. The differences between Fuji Bond LC adhesive with pre-cure and co-cure techniques were significant. Conclusion: This study encourages application of the Fuji bond LC adhesive with pre

  18. Marginal microleakage evaluation in class V composite restorations of deciduous teeth prepared conventionally and using Er:YAG laser

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    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 μm), 300 mJ, 3 Hz, handpiece 2051, energy density 86 mJ/cm2 + composite resin; Group 4 (G4) prepared using Er:YAG laser (2.94 μm), 300 mJ, 3 Hz, handpiece 2051, energy density 86 J / cm2 + 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 the viability of

  19. Effect of Loadcycling Number on Microleakage of Class V Preparation Restored with Composite and Total Etch Adhesives

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    MA haddad

    2013-08-01

    Full Text Available Introduction: Characteristics of Dental materials may be examined under stimulated oral conditions like loadcycling and Thermocycling. The aim of this study was to evaluate the effect of loadcycling on microleakage of class V cavity preparations restored with composite and total etch adhesives. Methods: One hundred class V preparations (5mm×3 mm and 2.5mm axial Depth with incisal margin in enamel and gingival margin in dentin, were prepared in the anterior bovine teeth. The teeth were randomly divided into two groups which restored with single Bond (3M-USA or excite (Ivaclar/viva dent/Lichtenstein. Each group was further divided into five subgroups. The numbers of used loadcycles involved respectively 0, 50k, 100k, 200k, 300k. [K=1000]; Then, all the teeth were covered with sticky wax except 1mm around the samples and were immersed in 2% methylene blue for 24 hours. Then all the teeth were sectioned longitudinally and the scores of Dye penetration were registered under stereomicroscope. The study data were analyzed using kruskal Wallis and Mann Whitney and wilcoxon tests. Results: All the dentin margins showed higher microleakage than enamel margin (P=0.0001. There was no significant difference between the microleakage of single bond and Excite(P>0/05. The effect of the number of loadcycles on the microleakage of the single bond and Excite in dentin and enamel margin was not significant. Conclusion: Enamel margins showed less microleakage than dentin margins. This study did not show any increase in microleakage after increasing the number of loadcycles

  20. Effect of light-curing unit and adhesive system on marginal adaptation of class v composite restorations.

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    Maia-Casseli, Denise S; Faria-e-Silva, André L; Cavalcanti, Andréa N; Romani, Eliene A O N; Martins, Luis R M

    2012-01-01

    The aim of this study was to evaluate the effect of light-curing units (LED or halogen) on the marginal adaptation of composite restorations performed with etch-and-rinse and self-etching adhesive. Class V cavities were prepared on bovine teeth with the gingival margin on dentin and the incisal margin on enamel. The cavities were restored with a micro-hybrid resin composite using an etch-and-rinse (Single Bond 2--SB) or a self-etching adhesive (Clearfil SE Bond--CL). The light-activations were performed using halogen lamp (Optilux 501--QTH) or second-generation light-emitting diode (Radii-Cal--LED) (n = 10). After finishing and polishing the restorations, epoxy replicas were prepared. The marginal adaptation was analyzed under scanning electronic microscopy with 500x of magnification. The greatest gap width at each margin was recorded. Data were submitted to Mann-Whitney and Wilcoxon tests (a = 0.05). SB and CL showed similar behavior of enamel margins when the light-activations were performed with QTH. The same was observed for dentin margins with LED. When the LED was used, higher gap measurements at enamel margins were observed with CL, while higher gap values in dentin were observed for SB within QTH. No significant difference between substrates was found when CL was used. However, SB had significantly higher gap measurements in dentin. The light-curing unit seems to affect the marginal adaptation of resin composite restorations. However this effect was dependent on the adhesive and the location of the margin. PMID:22928384

  1. The influence of caries disclosing agents and cavity disinfectants on microleakage of gingival floor of class V composite resin restorations

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    Safarcherati H

    2007-06-01

    Full Text Available Background and Aim: An important purpose of adhesive dentistry is restriction of cavity preparation to carious dentin removal and conservation of sound dentin. Application of caries disclosing agents and cavity disinfectants can help achieving this goal. The aim of this study was to evaluate the effect of caries disclosing agents and cavity disinfectants on microleakage of composite resin restorations. Materials and Methods: This experimental in-vitro study was performed on class V cavities in 48 extracted human sound premolars. The teeth were randomly divided into four equal groups. In group 1 caries detector dye (Seek, Ultradent, USA and in group 2 cavity disinfectant (Consepsis, Ultradent, USA were applied on dentinal surfaces. In group 3 both mentioned materials were applied. Group 4 was considered as control group. PQ1 bonding agent and Amelogen composite were used to restore the cavities. Gingival microleakage was assessed by dye penetration. Data were analyzed by Kruskall Wallis and Dunn tests. P<0.05 was the level of significance.Results: Group 2 showed the least and group 4 showed the highest microleakage;however no statistical significant difference was found among the groups.Conclusion: The use of caries disclosing agent (Seek and cavity disinfectant (Consepsis Liquid did not adversely affect the sealing ability of dentin bonding resins.

  2. The effect of surface sealants with different filler content on microleakage of Class V resin composite restorations

    Science.gov (United States)

    Hepdeniz, Ozge Kam; Temel, Ugur Burak; Ugurlu, Muhittin; Koskan, Ozgur

    2016-01-01

    Objective: Microleakage is still one of the most cited reasons for failure of resin composite restorations. Alternative methods to prevent microleakage have been investigated increasingly. The aim of this study is to evaluate the microleakage in Class V resin composite restorations with or without application of surface sealants with different filler content. Materials and Methods: Ninety-six cavities were prepared on the buccal and lingual surfaces with the coronal margins located in enamel and the cervical margins located in dentin. The cavities restored with an adhesive system (Clearfil SE Bond, Kuraray, Tokyo, Japan) and resin composite (Clearfil Majesty ES-2, Kuraray, Tokyo, Japan). Teeth were stored in distilled water for 24 h and separated into four groups according to the surface sealants (Control, Fortify, Fortify Plus, and G-Coat Plus). The teeth were thermocycled (500 cycles, 5–55° C), immersed in basic fuchsine, sectioned, and analyzed for dye penetration using stereomicroscope. The data were submitted to statistical analysis by Kruskal–Wallis and Bonferroni–Dunn test. Results: The results of the study indicated that there was minimum leakage at the enamel margins of all groups. Bonferroni–Dunn tests revealed that Fortify and GC-Coat groups showed significantly less leakage than the Control group and the Fortify Plus group at dentin margins in lingual surfaces (P < 0.05). Conclusion: The all surface sealants used in this study eliminated microleakage at enamel margins. Moreover, unfilled or nanofilled surface sealants were the most effective in decreasing the degree of marginal microleakage at dentin margins. However, viscosity and penetrability of the sealants could be considered for sealing ability besides composition. PMID:27095890

  3. 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

  4. Evaluation of microleakage occurred in class V restoration prepared with Er:YAG laser and also with high speed, restored using composite

    International Nuclear Information System (INIS)

    The microleakage is one of the great problems found in restoring dentistry. In spite of adhesive system evolution, several materials have been studied intending to minimize or to eliminate the microleakage occurred between the tooth and restorative material. The objective of this in vitro study was to evaluate and compare the marginal microleakage in class V cavities prepared by Er:YAG laser or high speed and restored with composite resin. One of the groups received the sodium bicarbonate jet while the other group have not received. Twenty teeth third extracted molars were sectioned in the sense medial-distal being obtained forty samples that were divided in four groups: Group I (G1): prepared with Er:YAG laser (2940 nm), E= 350 mJ/p, F=2 Hz, fluency of 112,5 J/cm2. Preparing occlusion margin slice with 250 mJ/p, F=2 Hz, fluency of 80,3 J/cm2. The prepared total area was irradiated with E=80 mJ/p, F=2 Hz and fluency of 25,75 J/cm2. Every prepared area was finally submitted to sodium bicarbonate jet. Group 2 (G2): it was employed the same parameters used on group 1, except the sodium carbonate jet application. Group 3 (G3): the cavities' prepare were executed with high speed rotation using diamond cylindrical point. The slice confection has been made with the same point with 45 degrees inclined, utilizing also the sodium carbonate jet in all prepared area. Group 4 (G4): it was executed similarly prepared to group 3, without the sodium bicarbonate jet. In all the groups the cavities were washed with water spray and drought with air jet. Dentin and enamel surfaces have been conditioned with phosphoric acid at 35%. All the samples of all groups were restored using the single bond system adhesive and composite resin Z250, kept at 37 deg C in stove during 24 hours, thermally stressed, immersed in silver nitrate solution at 50% for 24 hours while kept in darkness. The specimens were soaked in photo developing solution and exposed to fluorescent light for 6 hours. These

  5. Effect of aluminum chloride hemostatic agent on microleakage of class V composite resin restorations bonded with all-in-one adhesive

    Science.gov (United States)

    Mohammadi, Narmin; Bahari, Mahmood; Pournaghi-Azar, Fatemeh; Mozafari, Aysan

    2012-01-01

    Objectives: Since hemostatic agents can induce changes on enamel and dentin surfaces and influence composite resin adhesion, the aim of the present study was to evaluate the effect of the aluminum chloride hemostatic agent on the gingival margin microleakage of class V (Cl V) composite resin restorations bonded with all-in-one adhesive. Study design: Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors. Gingival margins of the cavities were placed 1.5 mm apical to the cemento-enamel junction (CEJ). The teeth were randomly divided into two groups of 30. In group 1, the cavities were restored without the application of a hemostatic agent; in group 2, the cavities were restored after the application of the hemostatic agent. In both groups all-in-one adhesive and Z250 composite resin were used to restore the cavities with the incremental technique. After finishing and polishing, the samples underwent a thermocycling procedure, followed by immersion in 2% basic fuschin solution for 24 hours. The samples were sectioned and gingival microleakage was evaluated under a stereomicroscope. The non-parametric Mann-Whitney U test was used to compare microleakage between the two groups. Statistical significance was defined at Padhesive with aluminum chloride hemostatic agent significantly increases restoration gingival margin microleakage. Key words:All-in-one adhesive resin, composite resin restoration, hemostatic agent, microleakage. PMID:22322497

  6. The effect of mechanical load cycling and polishing time on microleakage of class V glass-ionomer and composite restorations: A scanning electron microscopy evaluation

    Science.gov (United States)

    Mirzaie, Mansoreh; Yasini, Esmail; Kermanshah, Hamid; Omidi, Baharan Ranjbar

    2014-01-01

    Background: Microleakage is one of the challenging concerns in direct filling restorations. Understanding of its related factors is important in clinical practice. The aim of this study was scanning electron microscopy (SEM) evaluation of marginal integrity in three types of tooth-colored restorative materials in class V cavity preparations and the effect of load cycling and polishing time on the microleakage. Materials and Methods: In this in vitro experimental study, class V cavity preparations were prepared on the buccal and lingual surfaces of 60 bovine incisors. The specimens were divided into three groups each containing 20 teeth: group 1: Filtek Z350, Group 2: Fuji IX/G Coat Plus, Group 3: Fuji II LC/GC varnish. In each group, 2 subgroups (n = 20) were established based on finishing time (immediate or delayed by 24 h). All specimens were thermocycled (×2,000, 5-50°C). In each sub groups, half of the teeth were load cycled. Epoxy resin replicas of 24 specimens were evaluated under field emission-SEM and interfacial gaps were measured. All teeth were then immersed in 0.5% basic fuchsin dye for 24 h, sectioned and observed under stereomicroscope. Data were analyzed with Kruskal-Wallis’ test and Mann-Whitney U test and a comparison between incisal and cervical microleakage was made with Wilcoxon test. P effect on microleakage, but polishing time did not. Cervical microleakage in Z350/load cycle/immediate polish and Fuji IX/load cycle/immediate or delayed polish and Fuji IX/no load cycle/immediate polish were significantly higher than incisal microleakage. Conclusion: It was concluded that the cervical sealing ability of Fuji IX under load cycling was better than Fuji II LC. Under load cycling and immediate polishing Z350 showed better marginal integrity than both Fuji II LC and Fuji IX. The immediate polishing didn’t cause a statistically significant increase in microleakage of evaluated tooth-colored class V restorations. PMID:24688568

  7. Effect of the erbium:yttrium-aluminum-garnet laser or diamond bur cavity preparation on the marginal microleakage of class V cavities restored with different adhesives and composite systems.

    Science.gov (United States)

    Yaman, Batu Can; Guray, Begum Efes; Dorter, Can; Gomeç, Yavuz; Yazıcıoglu, Oktay; Erdilek, Dina

    2012-07-01

    The aim of this in vitro study was to compare the microleakage of Er:YAG laser and diamond bur on different bonding systems in class V restorations. Class V cavities were prepared with Er:YAG laser or diamond bur on 80 intact human molars. Teeth were randomly distributed into ten groups and cavities were restored with CeramX duo (DENTSPLY) or Filtek Silorane (3M/ESPE) using different bonding materials (One Coat 7.0 (Coltène), XP Bond (DENTSPLY), Clearfil Protect Bond (Kuraray), AdperSE (3M/ESPE), and Silorane System Adhesive (3M/ESPE). All specimens were subjected to thermocycling and load cycling. After being immersed in silver nitrate dye, the specimens were sectioned. Microleakage was evaluated by stereomicroscope and SEM. Data were statistically analyzed by one-way ANOVA, Kruskal-Wallis, and Mann-Whitney tests. Statistically differences were found between groups (p > 0.05) and cavities prepared with the Er:YAG laser showed higher microleakage than diamond bur. The microleakage of different bonding systems was influenced by the choice of diamond bur or Er:YAG laser for class V composite cavity preparation.

  8. Evaluation of microleakage occurred in class V restoration prepared with Er:YAG laser and also with high speed, restored using composite; Avaliacao da microinfiltracao em cavidades classe V preparada com laser de Er:YAG ou alta rotacao, jateadas ou nao com bicarbonato de sodio e restauradas com resina composta

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira, Angelo Maercio Finochio

    2002-07-01

    The microleakage is one of the great problems found in restoring dentistry. In spite of adhesive system evolution, several materials have been studied intending to minimize or to eliminate the microleakage occurred between the tooth and restorative material. The objective of this in vitro study was to evaluate and compare the marginal microleakage in class V cavities prepared by Er:YAG laser or high speed and restored with composite resin. One of the groups received the sodium bicarbonate jet while the other group have not received. Twenty teeth third extracted molars were sectioned in the sense medial-distal being obtained forty samples that were divided in four groups: Group I (G1): prepared with Er:YAG laser (2940 nm), E= 350 mJ/p, F=2 Hz, fluency of 112,5 J/cm{sup 2}. Preparing occlusion margin slice with 250 mJ/p, F=2 Hz, fluency of 80,3 J/cm{sup 2}. The prepared total area was irradiated with E=80 mJ/p, F=2 Hz and fluency of 25,75 J/cm{sup 2}. Every prepared area was finally submitted to sodium bicarbonate jet. Group 2 (G2): it was employed the same parameters used on group 1, except the sodium carbonate jet application. Group 3 (G3): the cavities' prepare were executed with high speed rotation using diamond cylindrical point. The slice confection has been made with the same point with 45 degrees inclined, utilizing also the sodium carbonate jet in all prepared area. Group 4 (G4): it was executed similarly prepared to group 3, without the sodium bicarbonate jet. In all the groups the cavities were washed with water spray and drought with air jet. Dentin and enamel surfaces have been conditioned with phosphoric acid at 35%. All the samples of all groups were restored using the single bond system adhesive and composite resin Z250, kept at 37 deg C in stove during 24 hours, thermally stressed, immersed in silver nitrate solution at 50% for 24 hours while kept in darkness. The specimens were soaked in photo developing solution and exposed to fluorescent

  9. The Class V lesion--aetiology and restoration.

    Science.gov (United States)

    Tyas, M J

    1995-06-01

    The aetiology of non-carious cervical lesions is discussed. These have been variously described as 'abrasion', 'erosion', 'abrasion/erosion', and 'idiopathic cervical'. However, many lesions do not fit the classical appearance or location of an erosive and/or abrasive origin, and there is increasing interest in the possible role of occlusal stress in their aetiology. Non-carious cervical lesions often require restoration, and there are essentially three options using tooth-coloured materials: a restorative glass ionomer cement, a liner/base glass ionomer cement overlayed with a resin composite, or a resin composite bonded by an enamel/dentine-adhesive. The materials and techniques used in these options are discussed, indicating their advantages and disadvantages. Results of available clinical trials of these systems are given, and the link with the stress theory of cervical tooth loss is described. The preferred restorative approaches in order are: resin-modified restorative glass ionomer; resin-modified liner/base glass ionomer with a microfine resin composite overlay; enamel/dentine bonding agent with a microfine resin composite.

  10. Avaliação in vitro da microinfiltração em cavidades de classe V restauradas com diferentes combinações de resina composta e cimento de ionômero de vidro In vitro evaluation of marginal leakage in class V restorations using different combinations of composite resin and glass ionomer cement

    Directory of Open Access Journals (Sweden)

    Régia Luzia ZANATA

    1998-04-01

    Full Text Available O propósito deste estudo foi comparar o padrão de microinfiltração em restaurações classe V usando diferentes combinações de cimento ionomérico/resina composta. Cinqüenta cavidades foram preparadas nas superfícies vestibular e lingual de caninos e de pré-molares recém-extraídos. A margem gengival dos preparos estendeu-se até a dentina/cemento, e a margem oclusal localizou-se em esmalte. As cavidades foram restauradas como se segue: cimentos ionoméricos restauradores modificados por componentes resinosos (Fuji II LC e Vitremer; sistema adesivo/resina composta (Scotchbond Multi-Uso/Silux Plus; técnica sanduíche empregando-se o sistema adesivo/resina composta descrito, com um cimento ionomérico forrador (Vitrebond e GC Lining LC. Os espécimes foram armazenados em água destilada, polidos, submetidos à ciclagem térmica e imersos em fucsina. A extensão de penetração do corante foi classificada segundo o critério de escores, e os dados foram analisados estatisticamente, não sendo observadas diferenças significativas tanto entre materiais como entre margens.The purpose of this study was to compare the microleakage of class V restorations using different combinations of glass ionomer/composite resin. Fifty cavities were prepared on the buccal and lingual aspects of recently extracted premolars and canines. The gingival margins of the preparations were extended into the cementum, and the occlusal margins were kept at the enamel level. The teeth were then divided into five groups and restored as follows: resin-modified glass ionomer cement restorative materials (Fuji II LC and Vitremer; composite resin/adhesive system (Scotchbond Multipurpose/Silux Plus; sandwich technique using the same composite resin/adhesive system and a resin-modified glass ionomer cement liner material (Vitrebond and GC Lining LC. The teeth were stored in distilled water, finished and thermocycled prior to immersion in a 2% basic fuchsin solution. The

  11. Influence of light intensity and curing cycle on microleakage of Class V composite resin restorations Influência da intensidade de luz e métodos de fotoativação no selamento marginal de restaurações classe V em resina composta

    Directory of Open Access Journals (Sweden)

    Maria Jacinta M. Coelho Santos

    2005-06-01

    Full Text Available The aim of this study was to determine the effect of a softstart polymerization method from Quartz-Tungsten-Halogen (QTH and Plasma Arc (PAC curing units on microleakage of Class V composite resin restorations with dentin cavosurface margins. Seventy-five bovine incisors received standardized class V cavities in all dentin margins. Teeth were divided into 5 equal groups according to the curing cycle. The cavities were incrementally restored with a composite resin (Single Bond/Z-100, 3M. Light curing was applied as follows: Group I: PAC light continuous-cycle curing at 1600 mW/cm² for 3s; Group II: PAC light step-cycle curing (2s at 800 mW/cm² then 4s at 1600 mW/cm²; Group III: QTH light continuous-cycle curing at 400 mW/cm² for 40s; Group IV: QTH light ramp-cycle curing (from 100 to 600 mW/cm² in 15s followed by 25s at 600 mW/cm²; Group V: QTH light pulse-delay curing (200 mW/cm² for 3s followed by 3 min delay then 600 mW/cm² for 30s. Teeth were stored in distilled water at 37ºC for 30 days and then subjected to thermocycling for 500 cycles at 5 and 55ºC. Root apices were sealed and teeth coated with nail varnish before they were immersed in 0.5% fuchsine red dye solution. Teeth were then sectioned and slices were scanned with a computer scanner to determine the area of dye leakage using a computer program (Image Tools. Images of tooth slices were also visually examined under magnification and dye penetration along the tooth/restoration interface was scored. Significant differences in the degree of dye penetration and leakage were detected between groups (pO objetivo deste estudo foi determinar o efeito da polimerização gradual, mediante a utilização de aparelhos de Quartzo-Tungustênio-Halógena (QTH e Arco de Plasma de Xenônio (PAC, no selamento marginal de restaurações classe V em resina composta com margens localizadas em dentina. Setenta e cinco incisivos bovinos receberam preparos de cavidades classe V, na raiz, com o

  12. In vitro evaluation of marginal microleakage in class V restorations with composite resin in bovine teeth. Laser irradiation influences and the adhesive system in the dentin pre-treatment; Avaliacao in vitro da microinfiltracao marginal em restauracoes de classe V com resina composta em dentes bovinos. Influencia da irradiacao laser e sistema adesivo no pre-tratamento dentinario

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Wendell Lima de

    2003-07-01

    Microleakage is one of the most important reasons to restorations failure, it is the responsible for marginal colors changing, new caries, hipersensibility and pulpar diseases. Several techniques and materials have been studied to eliminate or, at least, to decrease microleakage. The cavities preparation with Er:YAG laser and autoconditioning adhesive are some of these techniques and materials. This research has the objective to compare, in vitro, microleakage in class V cavities, prepared with high rotation (conventional treatment), Er:YAG laser (Enamel-400 mj/2 Hz/128,38 J/Cm{sup 2}, Dentin 250 mJ/ 2 Hz/ 80,24 J/Cm{sup 2}) and the treatment made at dentin with autoconditioning adhesive (Clerafil SE Bond) using Er:YAG laser (with water or not water) or not using Er:YAG laser. It was used 48 bovines teeth with cavities prepared in vestibular face and gingival wall on cement enamel junction and oclusal wall on enamel. The materials used were autoconditioning adhesive (Clerafil SE Bond) and composite resin Z250. Teeth were divided into four groups of twelve samples each one, according to dentin treatment. Group 1 - Conventional cavity and autoconditioning adhesive. Group 2- Cavity prepared with Er: YAG laser and autoconditioning adhesive. Group 3 - Cavity prepared with Er:YAG laser and dentin conditioning with Er:YAG laser associated to water and autoconditioning adhesive. Group 4 - Cavity prepared with Er:YAG laser and dentin conditioning with Er: YAG laser without water and associated to autoconditioning adhesive. Teeth were restored and stocked at 37 deg C, thermocycled and placed into a 50% silver nitrate solution. Right after, teeth were sliced and evaluated on a stereo microscopic magnifying glass in order to see microleakage degree trying to follow a score from 0 to 3. The findings were submitted to Fisher, Anderson-Darling tests and to the not parametric Sen and Puri test. The results indicated that in gingival edge, the Group 2 showed less microleakage than

  13. Influence of dental bleaching on marginal leakage of Class V restorations

    Directory of Open Access Journals (Sweden)

    Andréia Cristina Ramos Dorini

    2010-04-01

    Full Text Available Objective: Evaluate the in vitro effect of bleaching performed in the dental office and waiting time on the degree of microleakage in class V cavities with margins in enamel, restored with resin composite. Methods: Forty-five human third molars were used, in which the vestibular faces were bleached with 35% hydrogen peroxide activated with LED and the palatine faces were not bleached (control. The teeth were randomly divided into 3 groups with 15 teeth in each: Group 1, restored immediately after bleaching; Group 2, seven days after bleaching; and Group 3, fourteen days after bleaching. After cavity preparation, 35% phosphoric acid, Adper Single Bond 2 adhesive (3M ESPE, St. Paul, Mn, USA, and resin composite Filtek Z250 (3M ESPE, St. Paul, MN, USA were applied. The teeth were thermal cycled and sealed with red nail polish on the bleached faces and blue on the non bleached faces, except for 1mm around the restored region. The samples were classified according to the following scores: 0 = no leakage, 1 = minimum leakage (less than 1 / 3 the length of the wall, 2 = moderate leakage (1/3 to 2/3 of the wall and 3 = extensive leakage (over 2/3 of the wall. The data were submitted to the Kruskal-Wallis test at a level of significance of 5%. Results: The restorative procedure immediately after bleaching resulted in statistically higher microleakage values (p 0.05. Conclusion: Based on the results, it is advisable to wait at least 7 days after bleaching to make the definitive restoration.

  14. In vitro evaluation of marginal microleakage in class V restorations with composite resin in bovine teeth. Laser irradiation influences and the adhesive system in the dentin pre-treatment

    International Nuclear Information System (INIS)

    Microleakage is one of the most important reasons to restorations failure, it is the responsible for marginal colors changing, new caries, hipersensibility and pulpar diseases. Several techniques and materials have been studied to eliminate or, at least, to decrease microleakage. The cavities preparation with Er:YAG laser and autoconditioning adhesive are some of these techniques and materials. This research has the objective to compare, in vitro, microleakage in class V cavities, prepared with high rotation (conventional treatment), Er:YAG laser (Enamel-400 mj/2 Hz/128,38 J/Cm2, Dentin 250 mJ/ 2 Hz/ 80,24 J/Cm2) and the treatment made at dentin with autoconditioning adhesive (Clerafil SE Bond) using Er:YAG laser (with water or not water) or not using Er:YAG laser. It was used 48 bovines teeth with cavities prepared in vestibular face and gingival wall on cement enamel junction and oclusal wall on enamel. The materials used were autoconditioning adhesive (Clerafil SE Bond) and composite resin Z250. Teeth were divided into four groups of twelve samples each one, according to dentin treatment. Group 1 - Conventional cavity and autoconditioning adhesive. Group 2- Cavity prepared with Er: YAG laser and autoconditioning adhesive. Group 3 - Cavity prepared with Er:YAG laser and dentin conditioning with Er:YAG laser associated to water and autoconditioning adhesive. Group 4 - Cavity prepared with Er:YAG laser and dentin conditioning with Er: YAG laser without water and associated to autoconditioning adhesive. Teeth were restored and stocked at 37 deg C, thermocycled and placed into a 50% silver nitrate solution. Right after, teeth were sliced and evaluated on a stereo microscopic magnifying glass in order to see microleakage degree trying to follow a score from 0 to 3. The findings were submitted to Fisher, Anderson-Darling tests and to the not parametric Sen and Puri test. The results indicated that in gingival edge, the Group 2 showed less microleakage than others ones

  15. The effect of rebonding and liner type on microleakage of Class V amalgam restorations

    Directory of Open Access Journals (Sweden)

    Moosavi H.

    2008-10-01

    Full Text Available Background and Aim: Application of varnish and dentin bonding agents can effectively reduce microleakage under amalgam restorations. Also rebonding may show some effects on microleakage and its complications. The aim of this study was to evaluate the effect of liner/ adhesives on microleakage of Class V amalgam restoration with or without rebonding. Materials and Methods: In this in vitro study Class V cavities were prepared on sixty sound human maxillary premolars with the gingival floor 1mm below the CEJ. Cases were divided into six groups of ten teeth each. Specimens in group 1 and 2 were lined with Copalite and Scotchbond Multi-Purpose (SBMP respectively. In the third group (control no liner was applied. The teeth were then restored with spherical amalgam. Specimens in group 4 to 6 received the same treatments but after filling, the interfaces of restorations and teeth were etched with 37% phosphoric acid gel, rinsed and dried. Adhesive resin of SBMP was applied over amalgam and tooth margins and polymerized (rebonding. Specimens were thermocycled, exposed to dye and sectioned. Microleakage was graded (0-3 using a stereomicroscope at X40 magnification. Data were analyzed with Kruskal-Wallis, Mann-Whitney and Wilcoxon pair wise statistical tests. P<0.05 was considered as the limit of significance. Results: The groups lined with SBMP showed the lowest and the groups without liner the highest microleakage (p= 0.001. Significant difference was observed in microleakage mean rank of enamel and dentin margins (p=0.048. Rebonding with resin did not improve the seal (p> 0.05. Conclusion: Based on the results of this study, total etch adhesive system had significant effect on microleakage of Class V amalgam restorations especially in cervical margin. Rebonding did not show a significant effect on microleakage.

  16. Effect of resin liners on the microleakage of class V dental composite restorations Efeito do uso de forradores resinosos sobre a microinfiltração de restaurações classe V em compósito odontológico

    OpenAIRE

    Roberta Caroline Bruschi Alonso; Mário Alexandre Coelho Sinhoreti; Lourenço Correr Sobrinho; Simonides Consani; Mario Fernando de Goes

    2004-01-01

    PURPOSE: The aim of this study was to evaluate the effect of an adhesive applied in layers of different thickness or in association with a filled adhesive or with a low viscosity composite liner on the microleakage of composite restorations. METHODS: Forty bovine incisors were prepared with round cavities (4mm diameter X 2mm depth) on the cementoenamel junction. The teeth were assigned to four groups according to the liner used: 1 (control) - application of 1 layer of the Scotchbond Multi Pur...

  17. The competition between enamel and dentin adhesion within a cavity: an in vitro evaluation of class V restorations.

    Science.gov (United States)

    Bortolotto, Tissiana; Doudou, Wassila; Kunzelmann, Karl Heinz; Krejci, Ivo

    2012-08-01

    To gain more insight into the consequences of curing contraction within the tooth cavity, we assessed the margin behavior of 12 contemporary restorative systems in class V restorations with margins located on enamel and dentin after mechanical loading and water storage. Mixed class V cavities were prepared on extracted human molars and restored using five etch and rinse and seven self-etch adhesive systems with their corresponding composites. Marginal adaptation was evaluated by using a computer-assisted quantitative marginal analysis in a scanning electron microscope (SEM) on epoxy replicas before, after thermal and mechanical stressing and after 1 year of water storage. The interactions of "testing conditions", "adhesive-composite combination" and "tooth substrate" with "marginal adaptation" were evaluated by two-way ANOVA. Fatigue, stress and storage conditions had significant effects on the marginal adaptation. Only two groups (Optibond FL and G Bond) presented equal percentages of marginal adaptation on enamel and dentin; in the other groups, the rate of degradation was product dependent. All materials tested showed a distinct behavior on enamel and dentin. In addition to mechanical resistance and long-term stability, differences within materials also exist in their ability to simultaneously bond to enamel and dentin. PMID:22015462

  18. A protein-repellent and antibacterial nanocomposite for Class-V restorations to inhibit periodontitis-related pathogens.

    Science.gov (United States)

    Wang, Lin; Xie, Xianju; Imazato, Satoshi; Weir, Michael D; Reynolds, Mark A; Xu, Hockin H K

    2016-10-01

    The objectives of this study were to develop a bioactive dental composite and investigate the effects of 2-methacryloyloxyethyl phosphorylcholine (MPC) and dimethylaminohexadecyl methacrylate (DMAHDM) in Class V composite on mechanical properties, water sorption, protein adsorption, and inhibition of four species of periodontitis-related biofilms for the first time. The resin consisted of ethoxylated bisphenol A dimethacrylate (EBPADMA) and pyromellitic glycerol dimethacrylate (PMGDM). DMAHDM, MPC and nanoparticles of amorphous calcium phosphate (NACP) were incorporated into the resin. Four species (Porphyromonas gingivalis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum) were tested for biofilm colony-forming units (CFU), live/dead, metabolic activity, and polysaccharide production. The results showed that adding DMAHDM and MPC to the composite did not compromise the mechanical properties (p>0.1), with acceptable water sorption values. Composite with 3% MPC reduced protein adsorption to 1/9 that of a commercial composite (porders of magnitude via 3% DMAHDM+3% MPC, compared to control. The inhibition efficacy for the four species was: P. gingivalis>P intermedia=A. actinomycetemcomitans>F. nucleatum. In conclusion, a novel bioactive composite with 3% DMAHDM and 3% MPC achieved the greatest reduction in biofilm growth, metabolic activity and polysaccharide of four periodontal pathogens. The new composite is promising for Class V restorations especially with subgingival margins to inhibit periodontal pathogens, combat periodontitis and protect the periodontium. PMID:27287170

  19. Effect of resin liners on the microleakage of class V dental composite restorations Efeito do uso de forradores resinosos sobre a microinfiltração de restaurações classe V em compósito odontológico

    Directory of Open Access Journals (Sweden)

    Roberta Caroline Bruschi Alonso

    2004-03-01

    Full Text Available PURPOSE: The aim of this study was to evaluate the effect of an adhesive applied in layers of different thickness or in association with a filled adhesive or with a low viscosity composite liner on the microleakage of composite restorations. METHODS: Forty bovine incisors were prepared with round cavities (4mm diameter X 2mm depth on the cementoenamel junction. The teeth were assigned to four groups according to the liner used: 1 (control - application of 1 layer of the Scotchbond Multi Purpose adhesive system (SBMP; 2 - application of 3 layers of SBMP; 3 - application of 1 layer of SBMP followed by application of one layer of Optibond FL adhesive; 4 - application of one layer of SBMP followed by application of flowable composite Flow-it. All cavities were restored using composite resin Z100. The microleakage test was conducted according to ISO (TR11405. Data were analyzed by Kruskall-Wallis test (a=0.05. RESULTS: Group 4 showed less leakage than Group 1. Groups 2 and 3 showed intermediate values and there were no statistical differences when they were compared to the values of Groups 1 and 4 CONCLUSION: The use of resin liners with flowable composites can reduce the microleakage of composite restorations.OBJETIVO: O objetivo desse estudo foi avaliar os efeitos da aplicação de um adesivo em diferentes espessuras ou em associação com um adesivo com carga ou com compósito de baixa viscosidade na microinfiltração marginal de restaurações com compósito odontológico. MÉTODOS: Quarenta incisivos bovinos foram selecionados e cavidades circulares (4mm de diâmetro X 2mm de profundidade foram preparadas na região da junção cemento-esmalte. Os dentes foram então divididos em quatro grupos de acordo com o forramento utilizado: 1: (controle aplicação do sistema de união Scotchbond Multi Uso (SBMU - 1 camada de adesivo; 2: aplicação de 3 camadas do adesivo SBMU; 3: aplicação do SBMU, seguido pela aplicação de uma camada do adesivo

  20. Infiltração marginal em cavidades de classe V restauradas com materiais estéticos, utilizando diferentes técnicas restauradoras Microleakage in class V cavities restored with esthetic materials, using different restorative techniques

    Directory of Open Access Journals (Sweden)

    Eliza Maria Agueda RUSSO

    2001-06-01

    Full Text Available Este trabalho teve como objetivo avaliar, in vitro, a infiltração marginal em restaurações de classe V, executadas com resina composta (RC, cimento de ionômero de vidro resino-modificado (CIVRM e compômeros, por meio de diferentes técnicas restauradoras, e submetidas à ciclagem mecânica e térmica. Trinta e seis molares humanos íntegros receberam 72 preparos de classe V nas faces vestibular e lingual. A margem oclusal foi localizada em esmalte; a margem gengival, em dentina. Os dentes foram divididos em nove grupos de oito espécimes cada. As cavidades foram restauradas de acordo com as diferentes técnicas. Nos grupos 1, 2, 4 e 5, não foi feito condicionamento ácido. Após 24 horas em água a 37°C, as amostras sofreram ciclagem mecânica e térmica, imersão em rodamina B e secção no sentido vestíbulo-lingual. O grau de penetração variou de zero (infiltração a 3 (infiltração máxima. O teste Kruskal-Wallis revelou diferenças estatísticas significantes entre as técnicas restauradoras (p The purpose of this study was to compare the microleakage of class V cavities restored with composite resin (CR, resin-modified glass ionomer cement (RMGIC and polyacid-modified resin composite (PAMRC, using different clinical procedures. Thirty-six noncarious human molars were used in this study. A class V cavity, measuring approximately 3 mm x 4 mm x 2 mm, was prepared in each tooth in both buccal and lingual aspects, with a diamond bur (number 1,093 at high speed, with coolant water spray. The occlusal margin was located on enamel and the gingival margin was located on dentin. The teeth were divided into 9 groups with 8 specimens each. The cavities were restored according to different techniques. The specimens from groups 1, 2, 4 and 5 did not receive acid etching. The samples were stored in water at 37°C for 24 hours, subjected to occlusal load, thermocycled and immersed in rhodamine B. The restorations were then washed and sectioned

  1. MICROLEAKAGE OF CLASS V RESIN-MODIFIED GLASS IONOMER CEMENT AND COMPOMER RESTORATIONS IN VITRO

    Institute of Scientific and Technical Information of China (English)

    DING Ling; LU Yi; LU Qun; XU Qi-hua

    2006-01-01

    Objective To assess the microleakage of Class Ⅴ restorations made with two resin-modified glass ionomer cements (RMGICs) and two polyacid-modified composite resins (PMCRs). Methods Restorations of the four materials ( GC Fuji H LC, VitremerTM, Dyract AP and F2000TM ) were placed in facial Class Ⅴ cavity preparations in forty noncarious human molar teeth. Teeth were randomly assigned to 4 experimental groups of 10 teeth each. After thermal cycling( × 20, 5 -55℃ ), the interface between dentin and restorations was spattercoated with gold and observed under scanning electron microscopy (SEM). Then the square and average width of margin gaps of central 1/3 interface were recorded with image analysis software. Results The data indicated no significant differences between all the restorative materials for both occlusal and gingival margins. Further analysis revealed there were statistically significant differences between occlusal margins and gingival margins for VitremerTM and Dyract AP, respectively. Conclusion None of the tested materials guaranteed margins free of microleakage. Resin-modified glass ionomer cements showed similar margin gaps to the polyacid-modified composite resins tested.

  2. The effect of Er,Cr:YSGG laser irradiation different age patients on the microleakage of Class V resin composite restorations%Er,Cr∶YSGG激光预备不同年龄患者V类洞对复合树脂微渗漏的影响

    Institute of Scientific and Technical Information of China (English)

    王抒智; 贾兴亚; 杨超; 安欣; 杜健男; 李阳

    2013-01-01

    目的 研究比较Er,Cr∶YSGG激光与传统牙钻均分别预备老年及青年离体磨牙V类洞对复合树脂充填微渗漏的影响.方法 于2012年5月~9月,在中国医科大学口腔医院,将10颗老年及10颗青年因牙周病或阻生拔出的无龋坏、无充填物、无隐裂的磨牙,按预备方式不同,平均分为四组:第一组,老年高速;第二组,老年激光;第三组,青年高速;第四组 青年激光,每组5颗牙.经200次冷热循环染色后,将上述所有样本置于0.5%碱性品红溶液中浸泡24小时后,沿牙体长轴通过充填体正中纵行割开,在体视显微镜下根据染料渗入等级评分(0~3)及扫描电镜方法观察充填体微渗漏情况.结果 (牙合)壁和龈壁处,染料渗入结果显示,老年组和青年组染料渗入评分差异有统计学意义(P<0.05),老年组大于青年组;激光组和牙钻组差异无统计学意义(P>0.05).充填体边缘微缝隙宽度的结果显示,4组充填体边缘微缝隙宽度差异存在统计学意义(P<0.05),其中老年牙钻组的边缘微裂隙最大,青年激光组的边缘微裂隙最小.结论 在自酸蚀粘结剂的应用条件下,Er,Cr∶YSGG激光预备处理V类洞不能显著减少光固化复合树脂边缘微渗漏的发生;老年磨牙组与青年磨牙组相比较,无论是Er,Cr∶YSGG激光还是牙钻预备光固化复合树脂充填后,微渗漏评分及边缘微缝隙均大于青年磨牙组.%Objective The purpose of this study was to compare and study microleakage of Class V composite restorations following high-speed rotary and Er,Cr:YSGG laser preparation old and young molars. Methods From May 2012 to September, in the Stomatological Hospital of China Medical University ,caries-free vital ten old and ten young molars freshly extracted for periodontic or- orthodontic reasons were used in this study. Prepare different ways are divided into four groups:The first group old high-speed ;The second group old Er

  3. Longevity of Posterior Composite Restorations

    Science.gov (United States)

    Opdam, N.J.M.; van de Sande, F.H.; Bronkhorst, E.; Cenci, M.S.; Bottenberg, P.; Pallesen, U.; Gaengler, P.; Lindberg, A.; Huysmans, M.C.D.N.J.M.; van Dijken, J.W.

    2014-01-01

    The aim of this meta-analysis, based on individual participant data from several studies, was to investigate the influence of patient-, materials-, and tooth-related variables on the survival of posterior resin composite restorations. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a search resulting in 12 longitudinal studies of direct posterior resin composite restorations with at least 5 years’ follow-up. Original datasets were still available, including placement/failure/censoring of restorations, restored surfaces, materials used, reasons for clinical failure, and caries-risk status. A database including all restorations was constructed, and a multivariate Cox regression method was used to analyze variables of interest [patient (age; gender; caries-risk status), jaw (upper; lower), number of restored surfaces, resin composite and adhesive materials, and use of glass-ionomer cement as base/liner (present or absent)]. The hazard ratios with respective 95% confidence intervals were determined, and annual failure rates were calculated for subgroups. Of all restorations, 2,816 (2,585 Class II and 231 Class I) were included in the analysis, of which 569 failed during the observation period. Main reasons for failure were caries and fracture. The regression analyses showed a significantly higher risk of failure for restorations in high-caries-risk individuals and those with a higher number of restored surfaces. PMID:25048250

  4. Guidelines for Direct Adhesive Composite Restoration.

    Science.gov (United States)

    Society Of Cariology And Endodontology, Chinese Stomatological Association Csa

    2015-01-01

    Direct adhesive composite restoration, a technique to restore tooth defects by bonding composite resin materials, has been widely used in the restoration of dental caries or other tooth defects. Retention of composite resin restoration mainly relies on bonding strength between the materials and dental tissue. The clinical outcomes rely greatly on the regulated clinical practice of dentists. In 2011, the Society of Cariology and Endodontology of Chinese Stomatological Association (CSA) published the 'Practices and evaluation criteria of composite resin bonded restoration (Discussion Version)'. Since then, opinions and comments regarding the 'Discussion Version' have been widely circulated within the Society. The final version of the guideline was based on systematic reviews of scientific literature and requirements for the edit of technical guidelines, and through several rounds of discussions, revisions and supplements. The society recommends this guideline for clinicians to use in their practices, when conducting direct composite restorations.

  5. Effect of cooled composite inserts in the sealing ability of resin composite restorations placed at intraoral temperatures: an in vitro study.

    Science.gov (United States)

    de la Torre-Moreno, Francisco José; Rosales-Leal, Juan Ignacio; Bravo, Manuel

    2003-01-01

    Polymerization shrinkage causes microleakage of resin composite restorations. New materials and operative techniques should be developed in order to reduce polymerization shrinkage. This research studied the effects of cooled composite inserts and room-temperature composite inserts in the sealing ability of resin composite restorations placed at intraoral temperatures. Forty-eight extracted human molars (providing a total of 155 sections) were kept at intraoral temperatures, and Class V cavities were restored with an ormocer-based resin composite (Admira, Voco). Three restorative techniques were used: conventional bulk insertion (Group I or control group) (n = 53 sections), room-temperature resin composite inserts (Group II) (n = 52) and cooled resin composite inserts (Group III) (n = 50). Microleakage and penetrating microleakage were studied under the microscope. Cooled composite inserts reduce microleakage at the gingival margins with respect to Groups I (p = 0.002) and II (p = 0.014). When small-size cooled composite inserts were used, the sealing ability at the gingival margins of Class V composite restorations was improved with respect to the bulk insertion technique and the room-temperature composite inserts technique.

  6. Composite veneering of complex amalgam restorations.

    Science.gov (United States)

    Demarco, Flávio Fernando; Zanchi, César Henrique; Bueno, Márcia; Piva, Evandro

    2007-01-01

    In large posterior cavities, indirect restorations could provide improved performance when compared to direct restorations, but with higher cost and removal of sound tooth structure. Improved mechanical properties have resulted in good clinical performance for amalgam in large cavities but without an esthetic appearance. Resin composites have become popular for posterior restorations, mainly because of good esthetic results. A restorative technique is presented that combines the esthetic properties of directly bonded resin composite and the wide range of indications for amalgam in stress-bearing areas.

  7. DIRECT PERMANENT RESTORATIVES - AMALGAM VS COMPOSITE

    Directory of Open Access Journals (Sweden)

    Bhagyashree

    2013-11-01

    Full Text Available ABSTRACT: Dental restoration is the most commonly administered dental treatment. These restorations are subjected to dynamic conditions in oral cavity, are likely to fail and need replacement. Ideal restorative material should pass two tests - Longitivity and Esthetics. Longitivity of the restorative material depends on three major factors - first is Patient’s factors, second is Operator`s skills and last is the Restorative material itself. Dentists today have a plethora of materials to choose from. Materials like Silver Amalgam being tested over a century, other nubile but promising materials, developed recently and yet to be tested in long run. This puts a dentist in dilemma so as which material to select to ensure durable clinical p erformance after placement. Amalgam has been tested over 165 years and has fulfilled almost all desired qualities of a restorative material except esthetics. On the other hand composites have advantage in cases where esthetics is of prime importance; howev er Recent studies conclude them at par with amalgam 1 . Performance of these two materials is assessed on following criterions - Longevity, wear resistance, cost effectiveness, marginal leakage and predisposal to secondary decay, biocompatibility, pulp irri tation, tooth preparation, technique sensitivity and esthetics

  8. Effect of composite/amalgam thickness on fracture resistance of maxillary premolar teeth, restored with combined amalgam-composite restorations

    Science.gov (United States)

    Firouzmandi, Maryam; Doozandeh, Maryam; Abbasi, Sanaz

    2016-01-01

    Background Combined amalgam-composite restorations have been used through many years to benefit from the advantages of both dental amalgam and composite resin. Two variations have been mentioned for this technique, this study investigated the fracture resistance of maxillary premolar teeth with extended mesio-occluso-distal (MOD) cavities, restored with the two variations of combined amalgam-composite restorations. Material and Methods Sixty intact extracted premolar teeth were randomly divided into 6 groups (G1-G6) of 10 teeth. G1; consisted of intact teeth and G2; consisted of teeth with MOD preparations were assigned as the positive and negative control groups respectively. Other experimental groups after MOD preparations were as follows: G3, amalgam restoration; G4, composite restoration; G5 combined amalgam-composite restoration with amalgam placement only on 1mm of the gingival floor of the proximal boxes; G6, combined amalgam-composite restoration with amalgam placement to the height of contact area of the proximal surface of the tooth. Fracture strength of the specimens was measured and the data were analyzed using one-way analysis of variance (ANOVA). The level of significance was Pamalgam-composite restoration was similar to that achieved with composite restoration alone and more than that of amalgam restoration alone. It can be concluded that the thickness of amalgam in combined amalgam-composite restorations did not affect fracture resistance of the teeth. Key words:Amalgam, composite, fracture resistance, restoration. PMID:27398176

  9. Effect of composite/amalgam thickness on fracture resistance of maxillary premolar teeth, restored with combined amalgam-composite restorations

    Science.gov (United States)

    Firouzmandi, Maryam; Doozandeh, Maryam; Abbasi, Sanaz

    2016-01-01

    Background Combined amalgam-composite restorations have been used through many years to benefit from the advantages of both dental amalgam and composite resin. Two variations have been mentioned for this technique, this study investigated the fracture resistance of maxillary premolar teeth with extended mesio-occluso-distal (MOD) cavities, restored with the two variations of combined amalgam-composite restorations. Material and Methods Sixty intact extracted premolar teeth were randomly divided into 6 groups (G1-G6) of 10 teeth. G1; consisted of intact teeth and G2; consisted of teeth with MOD preparations were assigned as the positive and negative control groups respectively. Other experimental groups after MOD preparations were as follows: G3, amalgam restoration; G4, composite restoration; G5 combined amalgam-composite restoration with amalgam placement only on 1mm of the gingival floor of the proximal boxes; G6, combined amalgam-composite restoration with amalgam placement to the height of contact area of the proximal surface of the tooth. Fracture strength of the specimens was measured and the data were analyzed using one-way analysis of variance (ANOVA). The level of significance was Pcomposite restoration was similar to that achieved with composite restoration alone and more than that of amalgam restoration alone. It can be concluded that the thickness of amalgam in combined amalgam-composite restorations did not affect fracture resistance of the teeth. Key words:Amalgam, composite, fracture resistance, restoration. PMID:27398176

  10. Effect of Different Prophylaxis Methods on Microleakage of Microfilled Composite Restorations

    Science.gov (United States)

    Kimyai, Soodabeh; Mohammadi, Narmin; Alizadeh Oskoee, Parnian; Pournaghi-Azar, Fatemeh; Ebrahimi Chaharom, Mohammad Esmaeel; Amini, Melina

    2012-01-01

    Background and aims This study was aimed at evaluating the effect of different prophylaxis methods on microleak-age of microfilled composite restorations. Materials and methods In this in vitro study, class V cavities were prepared on buccal surfaces of 84 bovine teeth. The teeth were restored with Tetric N-Bond adhesive and Heliomolar composite resin. Subsequent to a thermocycling procedure and three months of storage in distilled water, the teeth were randomly assigned to four groups (n=21): (1) prophylaxis with a rubber cup and pumice; (2) prophylaxis with a brush and pumice; (3) prophylaxis with air/powder polishing device; and (4) no prophylaxis (the control group). Then the teeth were immersed in 2% basic fuchsin for 24 hours and sectioned for microleakage evaluation under a stereomicroscope. Data were analyzed using Kruskal-Wallis and Wilcoxon Signed Rankstests. Statistical significance was defined at pmargins exhibited significantly higher microleakage values compared to occlusal margins (peffect on marginal leakage of microfilled composite resin restorations. PMID:22991639

  11. SEM Evaluation of Internal Adaptation of Bases and Liners under Composite Restorations

    Directory of Open Access Journals (Sweden)

    Dimitrios Dionysopoulos

    2014-04-01

    Full Text Available The aim of this study was to evaluate the interfacial microgaps generating between different materials and between materials and dentin after polymerization of the composite restorations, using SEM. Methods: The materials investigated were a composite, an adhesive, a RMGI, and a calcium hydroxide. Thirty third molars were selected and two circular class V cavities (5 mm × 3 mm for each tooth were made. The teeth were randomly assigned into six groups and restored with a combination of the materials. The specimens were subjected to thermocycling and each tooth was sectioned mesiodistally in two halves. Each half was sectioned along the longitudinal axis through the center of the restorations to obtain a slice of 2 mm. The specimens were examined under SEM. The interfaces between the liners, the liners and dentin, and between the liners and the composite were examined for microgaps. Results: The results showed that there was not any significant difference in the mean width of microgaps in the interfaces between Dycal-dentin and Vitrebond-dentin (p>0.05. However, the width of microgaps in the interfaces between dentin-Clearfil Tri-S Bond was significantly smaller (p<0.05. The use of Clearfil Tri-S Bond reduced the possibility of microgap formation between the bonded interface and the materials tested.

  12. Benchmarking matching color in composite restorations

    Science.gov (United States)

    Migliau, Guido; Piccoli, Luca; Besharat, Laith Konstantinos; Romeo, Umberto

    2016-01-01

    Summary The purpose of this study was to investigate the color samples (A2, A3 and B1) of three different brands of resin composites using dentine masses. 135 discs were prepared (5 plates for each thickness, color and brand of composite material). A colorimetric evaluation, using white and black background, was performed just after preparation. The color was measured corresponding to “Vita” scale and ΔL, Δa, Δb and ΔE values were calculated using a spectrophotometer. The results showed that Value, Chroma and Hue often differ even if the same commercial color and same thickness is used. In conclusion, this study showed that the perfect aesthetics restoration is possible combining individual abilities, experience and correct techniques. PMID:27512531

  13. Benchmarking matching color in composite restorations.

    Science.gov (United States)

    Migliau, Guido; Piccoli, Luca; Besharat, Laith Konstantinos; Romeo, Umberto

    2016-01-01

    The purpose of this study was to investigate the color samples (A2, A3 and B1) of three different brands of resin composites using dentine masses. 135 discs were prepared (5 plates for each thickness, color and brand of composite material). A colorimetric evaluation, using white and black background, was performed just after preparation. The color was measured corresponding to "Vita" scale and ΔL, Δa, Δb and ΔE values were calculated using a spectrophotometer. The results showed that Value, Chroma and Hue often differ even if the same commercial color and same thickness is used. In conclusion, this study showed that the perfect aesthetics restoration is possible combining individual abilities, experience and correct techniques. PMID:27512531

  14. Fracture resistance of endodontically treated teeth restored with indirect composite inlay and onlay restorations – An in vitro study

    Directory of Open Access Journals (Sweden)

    Ibraheem F. Alshiddi

    2016-01-01

    Conclusion: Within the limitations of this study, endodontically treated teeth were successfully restored with indirect composite inlay and onlay restorations. However, the fractures that accompanied the inlay restorations were more severe and were unable to be restored.

  15. Effect of curing unit and adhesive system on marginal adaptation of composite restorations.

    Science.gov (United States)

    Casselli, Denise Sa Maia; Faria-e-Silva, Andre Luis; Casselli, Henrique; Martins, Luis Roberto Marcondes

    2012-01-01

    This study sought to evaluate how a curing unit and adhesive system affected the marginal adaptation of resin composite restorations. Class V cavities were prepared in bovine teeth with a gingival margin in dentin and an incisal margin in enamel. The cavities were restored with a micro-hybrid resin composite using one of four adhesives: Single Bond 2, Prime & Bond NT, Clearfil SE Bond, Xeno IV. The light-activations were performed using a quartz-tungsten-halogen (QTH) lamp or a second-generation light-emitting diode (LED). Restorations were finished and polished and epoxy replicas were prepared. Marginal adaptation was analyzed by using scanning electronic microscopy (magnification 500X). The widest gaps in each margin were recorded, and data were submitted to Kruskal-Wallis, Mann-Whitney, and Wilcoxon tests (α = 0.05). Differences between the adhesives were observed only when the dentin margins were evaluated: Clearfil SE Bond demonstrated better marginal adaptation than Prime & Bond NT or Single Bond 2 (which demonstrated the widest gaps in the dentin margin). The type of curing unit only affected the results for Xeno IV when the enamel margin was analyzed; the LED lamp promoted smaller gaps than the QTH lamp. PMID:23220321

  16. Effect of composite/amalgam thickness on fracture resistance of maxillary premolar teeth, restored with combined amalgam-composite restorations

    OpenAIRE

    Firouzmandi, Maryam; Doozandeh, Maryam; Jowkar, Zahra; Abbasi, Sanaz

    2016-01-01

    Background Combined amalgam-composite restorations have been used through many years to benefit from the advantages of both dental amalgam and composite resin. Two variations have been mentioned for this technique, this study investigated the fracture resistance of maxillary premolar teeth with extended mesio-occluso-distal (MOD) cavities, restored with the two variations of combined amalgam-composite restorations. Material and Methods Sixty intact extracted premolar teeth were randomly divid...

  17. Effect of composite/amalgam thickness on fracture resistance of maxillary premolar teeth, restored with combined amalgam-composite restorations

    OpenAIRE

    Firouzmandi, Maryam; Doozandeh, Maryam; Jowkar, Zahra; Abbasi, Sanaz

    2016-01-01

    Background: Combined amalgam-composite restorations have been used through many years to benefit from the advantages of both dental amalgam and composite resin. Two variations have been mentioned for this technique, this study investigated the fracture resistance of maxillary premolar teeth with extended mesio-occluso-distal (MOD) cavities, restored with the two variations of combined amalgam-composite restorations. Material and Methods: Sixty intact extracted premolar teeth were ...

  18. 12-year survival of composite vs. amalgam restorations.

    NARCIS (Netherlands)

    Opdam, N.J.M.; Bronkhorst, E.M.; Loomans, B.A.C.; Huysmans, M.C.D.N.J.M.

    2010-01-01

    Information about the long-term clinical survival of large amalgam and composite restorations is still lacking. This retrospective study compares the longevity of three- and four-/five-surface amalgam and composite restorations relative to patients' caries risk. Patient records from a general practi

  19. Smile transformations with the use of direct composite restorations.

    Science.gov (United States)

    Sameni, Abdi

    2013-01-01

    Mutual concerns shared by dentists and patients regarding removal of natural tooth structure affirm the need for non-invasive restorative treatments. Direct composite restorations are among today's conservative treatment modalities. Direct bonding procedures provide patients with an alternative to high biologic risk and expensive indirect porcelain restorations. This article discusses the principles involved in smile design cases, ways to successfully combine different treatment modalities, and materials to achieve outstanding esthetic and functional results. The article also demonstrates the versatility of today's composite materials for direct smile design restorations.

  20. Long-term deterioration of composite resin and amalgam restorations.

    Science.gov (United States)

    Smales, R J

    1991-01-01

    Previous long-term longitudinal studies of two different methods of placing an auto-cured conventional anterior composite resin, and of a low- and a high-copper amalgam alloy, had shown similar restoration survivals despite the different resin treatment methods used or the types of amalgam alloy placed. Therefore, the aim of the present study was to assess several clinical factors or characteristics of these restorations that were believed to affect the survival of the restorative materials. The 950 composite resin and the 1042 amalgam restorations examined were placed by many operators in numerous patients attending a dental hospital. The composite resin restorations were placed using unetched- and etched-enamel-bonding treatment methods, and the amalgam restorations were polished after insertion. Clinical ratings supplemented by color transparencies were used for the assessment of four factors for the resin, and four factors for the amalgam restoration. Significant deterioration differences were found for several of the clinical factors assessed for both the two different composite resin treatment methods, and for the two different amalgam alloys, which were not directly related to the restoration survivals. PMID:1840079

  1. Optimizing tooth form with direct posterior composite restorations.

    Science.gov (United States)

    Raghu, Ramya; Srinivasan, Raghu

    2011-10-01

    Advances in material sciences and technology have provided today's clinicians the strategies to transform the mechanistic approach of operative dentistry into a biologic philosophy. In the last three decades, composite resins have gone from being just an esthetically pleasing way of restoring Class III and Class IV cavities to become the universal material for both anterior and posterior situations as they closely mimic the natural esthetics while restoring the form of the human dentition. In order to enhance their success, clinicians have to rethink their protocol instead of applying the same restorative concepts and principles practiced with metallic restorations. Paralleling the evolution of posterior composite resin materials, cavity designs, restorative techniques and armamentarium have also developed rapidly to successfully employ composite resins in Class II situations. Most of the earlier problems with posterior composites such as poor wear resistance, polymerization shrinkage, postoperative sensitivity, predictable bonding to dentin, etc., have been overcome to a major extent. However, the clinically relevant aspect of achieving tight contacts in Class II situations has challenged clinicians the most. This paper reviews the evolution of techniques and recent developments in achieving predictable contacts with posterior composites. A Medline search was performed for articles on "direct posterior composite contacts." The keywords used were "contacts and contours of posterior composites." The reference list of each article was manually checked for additional articles of relevance.

  2. Optimizing tooth form with direct posterior composite restorations

    Directory of Open Access Journals (Sweden)

    Ramya Raghu

    2011-01-01

    Full Text Available Advances in material sciences and technology have provided today′s clinicians the strategies to transform the mechanistic approach of operative dentistry into a biologic philosophy. In the last three decades, composite resins have gone from being just an esthetically pleasing way of restoring Class III and Class IV cavities to become the universal material for both anterior and posterior situations as they closely mimic the natural esthetics while restoring the form of the human dentition. In order to enhance their success, clinicians have to rethink their protocol instead of applying the same restorative concepts and principles practiced with metallic restorations. Paralleling the evolution of posterior composite resin materials, cavity designs, restorative techniques and armamentarium have also developed rapidly to successfully employ composite resins in Class II situations. Most of the earlier problems with posterior composites such as poor wear resistance, polymerization shrinkage, postoperative sensitivity, predictable bonding to dentin, etc., have been overcome to a major extent. However, the clinically relevant aspect of achieving tight contacts in Class II situations has challenged clinicians the most. This paper reviews the evolution of techniques and recent developments in achieving predictable contacts with posterior composites. A Medline search was performed for articles on ′′direct posterior composite contacts.′′ The keywords used were ′′contacts and contours of posterior composites.′′ The reference list of each article was manually checked for additional articles of relevance.

  3. Voids in Sonic Fill(TM) restorations compared to traditional incrementally-filled composite restorations

    Science.gov (United States)

    Abourezq, Ibraheem A.

    SonicFill(TM) is a new composite resin and delivery system designed to provide rapid filling of cavity preparations by decreasing viscosity through application of sonic energy. However, it may produce unwanted air voids in the final restoration due to the short filling time. Air voids compromise long-term performance by providing weak foci, discontinuity at cavosurface margins and at internal cavity walls, and potential crack propagation. This study assessed the locations, sizes, and numbers of voids in SonicFill restorations compared with traditional composite resin restorations in a set of extracted molars with mesio-occlusal-distal (MOD) cavity preparations. Fifty noncarious intact extracted third molars were collected randomly from a large collection of discarded anonymous tooth specimens. Standardized MOD cavity preparations were cut, and teeth were assigned randomly to one of two groups ( n = 25). The first group was restored with SonicFill composite in two steps. The second group was restored with Herculite Ultra(TM) using an multiple increment layering technique (1-2 mm per layer). Cross-sectional images of the filling were taken by digital microscope. A total of 196 voids were found in the 50 specimens: 97 in SonicFill restorations and 99 in conventional restorations. Mean number of voids in SonicFill restorations was 3.88 versus 3.96 for conventional restorations. Mean percentage of void area in SonicFill restorations was 0.588% versus 0.508% for conventional restorations. Unpaired t tests for these differences indicated no statistically significant differences (p =.931 and p =.629, respectively). One-way ANOVA tests for mean void count and mean void area percentage differences by three location zones for conventional and SonicFill restorations also indicated no significant differences among the groups. The bulk-fill SonicFill system does not result in increased or decreased numbers or ii area of voids within Class II MOD restorations compared with a

  4. 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.

  5. [Restoring esthetics and function of posterior teeth using direct composite restoration].

    Science.gov (United States)

    Samet, N

    2001-10-01

    The growing demand for esthetic restorations in the posterior segments and the reports from all over the world concerning the possibility of a toxic effect of amalgam brought to the development of the composite resin materials. These allow excellent esthetic results without compromising the quality and long-term stability of the restorations. Out of the various types of posterior esthetic restorations, the most available are the direct ones. There are several substantial differences between fabricating amalgam or posterior composite restorations. The most significant difference concerns bonding to the tooth structures. The key to success in these restorations is the understanding of the reasons for failure, and the ways to prevent them. The failures are divided into two groups: biological failures--namely secondary caries, and mechanical failures--namely fracture and abrasion. The other key is understanding the materials used and their proper handling. This article illustrates in detail a step-by-step procedure the sequence of fabricating a posterior composite restoration in a posterior mandibular tooth, describing both techniques and materials used.

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

    Science.gov (United States)

    Santos, M J M C

    2015-01-01

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

  7. 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. PMID:20924063

  8. 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.

  9. Temperature Rise during Resin Composite Polymerization under Different Ceramic Restorations

    OpenAIRE

    Yondem, Isa; Altintas, Subutay Han; Usumez, Aslihan

    2011-01-01

    Objectives: The purpose of this study was to measure temperature increase induced by various light polymerizing units during resin composite polymerization beneath one of three types of ceramic restorations. Methods: The resin composite (Variolink II) was polymerized between one of three different ceramic specimens (zirconium oxide, lithium disilicate, feldspathic) (diameter 5 mm, height 2 mm) and a dentin disc (diameter 5 mm, height 1 mm) with a conventional halogen light, a high intensity h...

  10. Influence of different restorative techniques on marginal seal of class II composite restorations

    Directory of Open Access Journals (Sweden)

    Sinval Adalberto Rodrigues Junior

    2010-02-01

    Full Text Available OBJECTIVE: To evaluate the gingival marginal seal in class II composite restorations using different restorative techniques. MATERIAL AND METHODS: Class II box cavities were prepared in both proximal faces of 32 sound human third molars with gingival margins located in either enamel or dentin/cementum. Restorations were performed as follows: G1 (control: composite, conventional light curing technique; G2: composite, soft-start technique; G3: amalgam/composite association (amalcomp; and G4: resin-modified glass ionomer cement/composite, open sandwich technique. The restored specimens were thermocycled. Epoxy resin replicas were made and coated for scanning electron microscopy examination. For microleakage evaluation, teeth were coated with nail polish and immersed in dye solution. Teeth were cut in 3 slices and dye penetration was recorded (mm, digitized and analyzed with Image Tool software. Microleakage data were analyzed statistically by non-parametric Kruskal-Wallis and Mann-Whitney tests. RESULTS: Leakage in enamel was lower than in dentin (p<0.001. G2 exhibited the lowest leakage values (p<0.05 in enamel margins, with no differences between the other groups. In dentin margins, groups G1 and G2 had similar behavior and both showed less leakage (p<0.05 than groups G3 and G4. SEM micrographs revealed different marginal adaptation patterns for the different techniques and for the different substrates. CONCLUSION: The soft-start technique showed no leakage in enamel margins and produced similar values to those of the conventional (control technique for dentin margins.

  11. Early failure of Class II resin composite versus Class II amalgam restorations placed by dental students.

    Science.gov (United States)

    Overton, J D; Sullivan, Diane J

    2012-03-01

    Using the information from remake request slips in a dental school's predoctoral clinic, we examined the short-term survival of Class II resin composite restorations versus Class II dental amalgam restorations. In the student clinic, resin composite is used in approximately 58 percent of Class II restorations placed, and dental amalgam is used in the remaining 42 percent. In the period examined, Class II resin composite restorations were ten times more likely to be replaced at no cost to the patient than Class II dental amalgam restorations. A total of eighty-four resin composite restorations and six amalgam restorations were replaced due to an identified failure.

  12. A clinical evaluation on adhesive posts in extensive composite restorations

    Directory of Open Access Journals (Sweden)

    Ghavamnasiri M. Associate Professor

    2003-06-01

    Full Text Available Problem: A few studies have been conducted about bioglass posts."nAim: The aim of this study was to compare bioglass posts with prefabricated metallic posts in clinical performance of extensive composite restorations for anterior endodontically treated teeth. Materials and Methods: Sixty endodontocally maxillary anterior teeth, with horizontally or vertically destruction, were selected. Teeth were divided into two groups based on the kind of post: Metallic prefabricated parapost and bioglass post. Each group was divided into three subgroups based on anterior bite: normal, deep bite and edge to edge. Gutta-percha was removed from 2/3 of canal length for parapost and 1/3 for bioglass post. After etching with phosphoric-acid (37% and applying dentine bonding syntac, Duo cement was used for the adhesion of bioglass post and a self cured composite (Degufil for parapost. Restoration was done with a hybrid composite (Heliomolar. Follow up studies, radio-graphically and clinically, were done every three months for a 1.5-year period. Exact Fisher and Pearson tests were used for data analysis."nResults: Apical lesion was not observed in any of the radiographs. Post seal was increased by resin cement and dentin bonding agent. Post type did not significantly affect on the clinical success rate of the restorations. The retention of restoration, for both posts, was the same. Crown destruction had no significant effect on success rate. The type of anterior bite had a significant effect on success rate, as the total 6.6% failure rate was related to the patients with anterior deep bite."nConclusion: It is suggested to use metallic paraposts and bioglass posts, in extensive composite restorations for patients with deep-bite, more conservatively.

  13. The effect of oxalate desensitizers on the microleakage of resin composite restorations bonded by etch and rinse adhesive systems.

    Science.gov (United States)

    Shafiei, Fereshteh; Motamedi, Mehran; Alavi, Ali Asghar; Namvar, Babak

    2010-01-01

    This in vitro study evaluated the effect of an oxalate desensitizer (OX) on the marginal microleakage of resin composite restorations bonded by two three-step and two two-step etch and rinse adhesives. Class V cavities were prepared on the buccal surfaces of 126 extracted premolars at the cementoenamel junction and randomly divided into nine groups of 14 each. In the control groups (1-4), four adhesives were applied, respectively, including Adper Scotchbond Multi-Purpose (SBMP), Optibond FL (OBFL), One-Step Plus (OS) and Excite (EX). In the experimental groups (5-8), the same adhesives, in combination with OX (BisBlock), were applied. And, in one group, OX was applied without any adhesive, as the negative control group (9). All the groups were restored with a resin composite. After 24 hours of storage in distilled water and thermocycling, the samples were placed in 1% methylene blue dye solution. The dye penetration was evaluated using a stereomicroscope. The data were analyzed using non-parametric tests. The OX application, in combination with OBFL and EX, resulted in significantly increasing microleakage at the gingival margins (p 0.05). At the occlusal margins, no significant difference in microleakage was observed after OX application for each of four adhesives (p > 0.05). PMID:21180008

  14. Restoration or Disturbance: Assessing the Impacts of a Salmon Habitat Restoration Project on Riparian Vegetation Composition

    OpenAIRE

    Azevedo, Andhra; Chin, Larissa; Dullemond, Kia; Morton, Lovena; Naghshinepour, Negar; Salihue, Hafsa

    2013-01-01

    Invasive plant species can threaten the biodiversity and resilience of riparian ecosystems. A vegetation assessment of the riparian zone beside the Stoney Creek Off-Channel Habitat Project compared with a non-restored site and a previously replanted site showed that the sites were significantly different in their vegetation composition. All three sites had several invasive species of concern playing dominant roles in the ecosystem with the most common two species being English ivy (Hedera hel...

  15. Composite restorations: influence of flowable and self-curing resin composite linings on microleakage in vitro.

    Science.gov (United States)

    Peutzfeldt, Anne; Asmussen, Erik

    2002-01-01

    This in vitro study evaluated the microleakage at enamel (occlusal) and dentin (gingival) margins of MOD resin composite restorations made with different incremental insertion techniques. MOD cavities were prepared on 60 extracted human molars with the proximal margins placed 1 mm below the cemento-enamel junction. All teeth were acid-etched and treated with One-Step adhesive, then restored with a hybrid resin composite (Renew) with and without a flowable composite (AEliteflo) or a self-curing composite (Bisfil 2B) as the first increment in the proximal boxes. The time of placement of the second increment in relation to curing of the first increment was also varied. After polishing, the teeth were soaked in 0.5% basic fuchsin for 24 hours, sectioned and evaluated for dye penetration. None of the restorative techniques prevented microleakage at the enamel and dentin margins. However, microleakage at dentin margins were significantly reduced by the use of a flowable composite as the first increment in the proximal boxes. Time of placement in relation to curing had no influence on microleakage. Microleakage was lower at enamel margins than at dentin margins; however, besides microleakage at the enamel-restoration interface, 37 of the 60 restored teeth (62%) displayed at least one white line in enamel adjacent to the composite restoration. PMID:12413221

  16. Characterisation and Performance of Fibre-Reinforced Composite Restorations

    OpenAIRE

    Al-Haddad, Ala'A

    2015-01-01

    In the modern era of metal-free minimally-invasive dentistry, there is a growing tendency toward using metal-free restorative alternatives that provide not only excellent aesthetics but also enable superior durability. Fibre-reinforced composite (FRC) is one cost-effective alternative that fulfils the requirements of aesthetics and durability, and offers favourable physico-mechanical properties. Many FRC applications are well-documented in the literature, such as crowns and fixed partial dent...

  17. Recent Advances and Developments in Composite Dental Restorative Materials

    OpenAIRE

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

    2011-01-01

    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 t...

  18. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid

    International Nuclear Information System (INIS)

    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0-3) by

  19. Microleakage of Class II Combined Amalgam-Composite Restorations Using Different Composites and Bonding Agents

    Directory of Open Access Journals (Sweden)

    F. Sharafeddin

    2008-09-01

    Full Text Available Objective: The purpose of the present study was to assess the microleakage of composite restorations with and without a cervical amalgam base and to compare the results of dif-ferent composites and bonding agents.Materials and Methods: One hundred and twenty mesio-occlusal (MO and disto-occlusal (DO Class II cavities were prepared on sixty extracted permanent premolar teeth. The teeth were randomly divided into four groups of 30 and restored as follows:In group A, the mesio-occlusal cavity (MO, Scotchbond multi purpose plus + Z250 and in the disto-occlusal (DO cavity, Prompt-L-Pop + Z250 were applied. As for group B, in the MO and DO cavities, Clearfil SE Bond + Clearfil APX, and varnish + amalgam (In box + Clearfil SE Bond + Clearfil APX were used respectivelywhile in group C; the teeth were restored with amalgam and varnish mesio-occlusally and with amalgam only disto-occlusally. As for group D, varnish + amalgam (in box + Scotchbond multi purpose plus + Z250 were applied mesio-occlusally and Varnish + Amalgam (in box + Prompt–L–Pop + Z250 disto-occlusally.Marginal leakage was assessed by the degree of dye penetration into various sections of the restored teeth. Chi-square and Fisher's exact tests were used for data analysis.Results: Microleakage in gingival margin was more than that in occlusal margin (P<0.05 and microleakage of combined amalgam-composite restorations was significantly lower than that of conventional composite and amalgam restorations.Conclusion: Marginal microleakage decreased by using amalgam at the base of the box in Class II composite restorations.

  20. Fracture resistance of teeth restored with packable and hybrid composites

    Directory of Open Access Journals (Sweden)

    Ghavam M

    2006-06-01

    Full Text Available Background and Aim: With recent introduction of packable composites, it is claimed that they apply less stress on tooth structure because of reduced polymerization shrinkage, and similarity of coefficient of thermal expansion to tooth structure. However, the high viscosity may in turn cause less adaptation, so it is not clearly known whether these materials strengthen tooth structure or not. The aim of this study was to evaluate fracture resistance of maxillary premolars, receiving hybrid or packable composite restorations with different methods of application and curing. Materials and Methods: In this experimental study, seventy five intact premolars were randomly assigned to five groups of 15 teeth each. One group was maintained intact as the control group. Similar MOD cavities were prepared in the other teeth. The teeth in group two were restored with Spectrum in incremental layers and light cured with 500 mw/cm2 intensity. The third group were filled with Surefil and cured with light intensity of 500 mw/cm2. The groups four and five were restored with Surefil in bulk technique with two different modes: 500 mw/cm2 intensity and a ramp mode (100-900 mw/cm2 respectively. After thermocycling, force to fracture was assessed and degree of conversion (DC at the bottom of cavities was evaluated for different modes and methods. The curing and placement methods in groups tested for DC (A to D were the same as fracture resistance groups (2 to 5. Data were analyzed using one way ANOVA and Tukey HSD tests with p<0.05 as the limit of significance. Results: All the restored groups showed significantly less fracture resistance than the control group, but had no significant difference among themselves. DC of Spectrum was higher than Surefil. Bulk method with 500 mw/cm2 light intensity, significantly decreased DC. DC in bulk method with high light intensity was not significantly different from incremental method with 500 mw/cm2 light intensity. Conclusion

  1. Evaluation of periodontal status adjacent to interproximal surfaces restored with composite resin, in comparison with non-restored interproximal surfaces

    Directory of Open Access Journals (Sweden)

    Elvia Christina Barros de Almeida

    2008-01-01

    Full Text Available Objective: The purpose of this study was to evaluate the periodontal status of interproximal surfaces restored with composite resin, in comparison with non-restored interproximal surfaces. Methods: In 65 patients, we analyzed 145 restored surfaces and 145 non-restored surfaces. Results: Most of the restored surfaces (54.3% showed radiographic alterations, which was shown to be higher among restorations with clinically detected proximal excess (56.8% x 52.8%; with lack of restorative material (64.5% x 51.4%; in restorations with proximal overhang (67.7% x 44.4%; in teeth with gingival inflammation?/bleeding (55.1% x 40.0% and in teeth with probing depth exceeding 3 mm (64.3% x 52.9%. However, there were no significant associations for these variables. Of the non-restored surfaces, 24.4% showed radiographic alterations, however there were no significant associations. Conclusion: The results showed a statistical significance for radiographic alterations in restored and non-restored surfaces.

  2. Effect of Unfilled Resin Sealant Surface Coating on the Marginal Leakage of Two Cervical Restorations Viz Light Curing Nanoglass Ionomer and Nanoceramic Composite-An In vitro Stereomicroscopic Dye Penetration Study

    Directory of Open Access Journals (Sweden)

    Nandan Rao K

    2011-07-01

    Full Text Available The purpose of this study is to compare the marginal leakage of two aesthetic cervical restorative materials viz the newly introduced light cured nano glass ionomer cement and nano ceramic composites, and also to evaluate the effect of unfilled resin sealant coating on marginal leakage of these aesthetic restorations. Thirty freshly extracted human upper premolars were used for the study. Class V cavities were prepared on the buccal and lingual surface of each tooth, with occlusal margin in enamel and cervical margin in cementum. The teeth were randomly divided into two groups of fifteen teeth each. Cavities of group 1 were restored with nano composite and group 2 were restored with light curing nano glass ionomer cement, following manufacturer’s instructions. After rinsing and drying one thin coat of unfilled resin sealant was applied only on to the surface of lingual restoration and were light polymerized for 15 seconds. The procedures for dye penetration using Methylene Blue were followed and examined under stereomicroscope for evaluation. The data collected were analyzed statistically using Mann-Whitney U test. Nanocomposite recorded less microleakage than nanoglass ionomer cement at occlusal and cervical margins. Results showed that cervical margin had significantly more microleakage than occlusal margin. Palatal surfaces, which were coated with resin sealant showed significantly less dye penetration in comparison with buccal surfaces in both groups. Though the coating of unfilled resin sealant did not completely eliminated microleakage, unfilled resin sealant was definitely effective in reducing microleakage of the esthetic restorations, especially on the gingival margin of the class V restorations.

  3. Microleakage of Class II Combined Amalgam-Composite Restorations Using Different Composites and Bonding Agents

    OpenAIRE

    F. Sharafeddin; H. Moradian

    2008-01-01

    Objective: The purpose of the present study was to assess the microleakage of composite restorations with and without a cervical amalgam base and to compare the results of dif-ferent composites and bonding agents.Materials and Methods: One hundred and twenty mesio-occlusal (MO) and disto-occlusal (DO) Class II cavities were prepared on sixty extracted permanent premolar teeth. The teeth were randomly divided into four groups of 30 and restored as follows:In group A, the mesio-occlusal cavity ...

  4. A new proposal to optimize the occlusal margin in direct resin composite restorations of posterior teeth.

    Science.gov (United States)

    Schlichting, Luís Henrique; Monteiro, Sylvio; Baratieri, Luiz Narciso

    2008-01-01

    Modern operative dentistry provides practitioners of esthetic dentistry the means for performing direct restorations in a virtually imperceptible way. However, this attribute of resin composite can cause difficulties because the absence of contrast between the tooth structure and the restoration can impede visualization of the cavity limits. The purpose of this article is to highlight some operative steps that, when appropriately performed, will facilitate the building of direct resin composite restorations in posterior teeth, significantly reducing the possibility of restorative overextension.

  5. Curing units' ability to cure restorative composites and dual-cured composite cements under composite overlay.

    Science.gov (United States)

    Park, Sung-Ho; Kim, Su-Sun; Cho, Yong-Sik; Lee, Chang-Kyu; Noh, Byng-Duk

    2004-01-01

    This study compared the efficacy of using conventional low-power density QTH (LQTH) units, high-power density QTH (HQTH) units, argon (Ar) laser and Plasma arc curing (PAC) units for curing dual-cured resin cements and restorative resin composites under a pre-cured resin composite overlay. The microhardness of the two types of restorative resins (Z100 and Tetric Ceram) and a dual-cured resin cement (Variolink II) were measured after they were light cured for 60 seconds in a 2 mm Teflon mold. The recorded microhardness was determined to be the optimum microhard-ness (OM). Either one of the two types of restorative resins (Z100, Tetric Ceram) or the dual cured resin cement (Variolink II) were placed under a 1.5-mm thick and 8 mm diameter pre-cured Targis (Vivadent/Ivoclar AG, Schaan, Liechtenstein) overlay. The specimens that were prepared for each material were divided into four groups depending upon the curing units used (HQTH, PAC, Laser or LQTH) and were further subdi-vided into subgroups according to light curing time. The curing times used were 30, 60, 90 and 120 seconds for HQTH; 12, 24, 36 and 48 seconds for the PAC unit; 15, 30, 45 and 60 for the Laser and 60, 120 or 180 seconds for the LQTH unit. Fifteen specimens were assigned to each sub- group. The microhardness of the upper and and lower composite surfaces under the Targis overlay were measured using an Optidur Vickers hardness-measuring instrument (Göttfert Feinwerktechnik GmbH, Buchen, Germany). In each material, for each group, a three-way ANOVA with Tukey was used at the 0.05 level of significance to compare the microhardnesses of the upper and lower composite surfaces and the previously measured OM of the material. From the OM of each material, 80% OM was calculated and the time required for the microhardness of the upper and lower surface of the specimen to reach 100% and 80% of OM was determined. In Z100 and Tetric Ceram, when the composites were light cured for 120 seconds using the HQTH lamp

  6. The stamp technique for direct Class II composite restorations: A case series

    Science.gov (United States)

    Alshehadat, Saaid Ayesh; Halim, Mohamad Syahrizal; Carmen, Koh; Fung, Chew Shi

    2016-01-01

    Background: “Stamp” technique is a new method for placing large composite restorations with accurate occlusal topography. It was introduced mainly to restore Class I cavities and erosively damaged teeth. This technique is indicated when the preoperative anatomy of the tooth is intact and not lost due to the carious lesion. A precise tooth-like filling an accurate functional occlusion is obtained when the stamp technique is applied. However, using this technique to restore Class II cavities is not established yet. Aim: To introduce modifications of the stamp technique that make it applicable to restore Class II composite restorations. Materials and Methods: The traditional materials and tools used for direct composite restorations are needed with no additional instruments. Clinical illustrations and step-by-step description are provided in this paper. Results and Conclusion: Using the stamp technique to restore Class II cavities is achievable, simple and practical, and result in a very accurate anatomical restoration. PMID:27656074

  7. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid; Estudo in vitro da microinfiltracao marginal em cavidades classe V preparadas com laser de Er:YAG e condicionadas com acido ou com laser de Er:YAG e acido

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Henrique Dutra Simoes

    2001-07-01

    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0

  8. Marginal and internal adaptation of class II restorations after immediate or delayed composite placement

    OpenAIRE

    Dietschi, Didier; Monasevic, Manuela; Krejci, Ivo; Davidson, Carel

    2002-01-01

    Direct class II composite restorations still represent a challenge, particularly when proximal limits extend below the CEJ. The aim of this in vitro study was to evaluate the influence of the type of adhesive and the delay between adhesive placement and composite insertion on restoration adaptation. Direct class II MOD box-shaped composite restorations (n=8 per group) were placed on intact human third molars, with proximal margins 1mm above or under CEJ. All cavities were filled with a horizo...

  9. Microshear bond strength between restorative composites and resin cements

    Directory of Open Access Journals (Sweden)

    Rubens Nazareno GARCIA

    2008-08-01

    Full Text Available Introduction and objective: The techniques of adhesive cementationhave been widely used in dental restoration. The purpose of this studywas to evaluate the microshear bond strength between restorativecomposites and resin cements. Material and methods: Twenty composites blocks were prepared in order to obtain a flat surface, using 600-grid sandpaper. The samples were randomly divided in four groups(n=15 according to the experimental groups: [1] Z250 block + Single Bond + cylinder of RelyX ARC; [2] Z250 block + Single Bond + cylinder of Panavia F; [3] Clearfil AP-X block + Clearfil SE Bond adhesive + cylinder of RelyX ARC; [4] Clearfil AP-X block + Clearfil SE Bond adhesive + cylinder of Panavia F. The adhesive systems and the resin cements were applied according to the experimental groups, using a Tygon matrix.The samples were stored in distilled water at 37±2ºC for 24 hours.Microshear bond strengths were determined using an apparatus attached to an Instron universal testing machine at a crosshead speed of 0.5 mm/minute. Results: The results obtained in MPa (SD were statistically analyzed (ANOVA and Tukey test, p<0.05, and showed the following results: [1] 39.76 (5.34; [2] 45.01 (8.53; [3] 46.39 (9.22; [4]45.78 (9.06.There was no statistically significant difference between groups [1] and [2]; and between groups [3] and [4]. However, there was statistically significant difference between groups [1] and [3]. Conclusion:When Clearfil AP-X block was used with Clearfil SE Bond adhesive or RelyX resin cement, the microshear bond strength values were higher.The results suggest that in the union of the resin cements to the restorative composites, hydrophobic adhesives are necessary.

  10. Considerations Regarding the Optical Properties of the Composite Resin Restorative Materials

    OpenAIRE

    Manolea, H.; Râcă, R.; Coleş, Evantia; Preotu, Gabriela; Mărăşescu, P.

    2011-01-01

    The purpose of this study has been to investigate the effects of certain substances frequently used in alimentation on the color stability of the composite resin restorative materials. The research hypothesis was that color stability of the composite resin is affected by the type of composite material used and by the polishing procedure. 14 samples of 5X15X2mm have been prepared from seven universal light curing restorative composite resins. The materials have manipulated and cured using LA 5...

  11. Comparative in vivo evaluation of restoring severely mutilated primary anterior teeth with biological post and crown preparation and reinforced composite restoration

    Directory of Open Access Journals (Sweden)

    Grewal N

    2008-01-01

    Full Text Available Background: This study was designed to compare the success rate of biological and composite restorations when used to replace structural loss of primary anterior teeth using intracanal post for radicular support of the restoration. Materials and Methods: Forty-two patients aged between 3-5 years presenting with early childhood caries (ECC received at least one or more composite and biological restorations for comparative evaluation. A total of 150 restorations were done (75 biological restorations and 75 composite restorations. The restorations were evaluated single-blind according to a modified USPHS system. Assessment of the patient′s response in accepting a biological restoration, psychological impact of the restorations, view of the parents, and peer group reviews, etc. were recorded in a response sheet in presence of the child and the parents. Observations and Results: In vivo clinical performance of biological post and crown restorations and intracanal reinforced composite restorations was comparable with respect to shade match, marginal discoloration, marginal integrity, surface finish, gingival health, retention, and recurrent carious lesions. The cost effectiveness of biological restorations was certainly a positive attribute. Conclusion: The biological restoration presented as a cost effective, clinician friendly, less-technique sensitive, and esthetic alternative to commercially available restorative materials used for restoring deciduous teeth affected by ECC.

  12. Anterior composite restorations: A systematic review on long-term survival and reasons for failure

    NARCIS (Netherlands)

    Demarco, F.F.; Collares, K.; Coelho-de-Souza, F.H.; Correa, M.B.; Cenci, M.S.; Moraes, R.R.; Opdam, N.J.M.

    2015-01-01

    OBJECTIVE: In this study the literature was systematically reviewed to investigate the clinical longevity of anterior composite restorations. DATA: Clinical studies investigating the survival of anterior light-cured composite restorations with at least three years of follow-up were screened and main

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

    NARCIS (Netherlands)

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

    2007-01-01

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

  14. 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

    Summary Aim To determine and compare the fracture resistance of endodontically treated teeth restored with a bulk fill flowable material (SDR) and a traditional resin composite. Methods 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 (Pendodontically treated teeth restored with a traditional resin 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. Conclusions 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. PMID:27486505

  15. Five-year clinical performance of posterior resin composite restorations placed by dental students.

    NARCIS (Netherlands)

    Opdam, N.J.M.; Loomans, B.A.C.; Roeters, F.J.M.; Bronkhorst, E.M.

    2004-01-01

    OBJECTIVES: To investigate the survival over a five-year period of posterior resin composite restorations placed by students. METHODS: Class I and II resin composite restorations placed by second-fourth year dental students were evaluated. Patients attended the dental school every 6 months for a reg

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

    Science.gov (United States)

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

    2013-01-01

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

  17. Fracture resistance of endodontically treated teeth restored with indirect composite inlay and onlay restorations – An in vitro study

    Science.gov (United States)

    Alshiddi, Ibraheem F.; Aljinbaz, Amjad

    2015-01-01

    Objective The purpose of this in vitro study was to evaluate and compare the fracture resistance and fracture mode of extensive indirect inlay and onlay composite resin restorations performed for endodontically treated premolars. Materials and methods A total of 55 extracted maxillary premolars were randomly divided into four groups. The first group (n = 15) remained untreated to serve as a positive control; the second group (n = 15) was endodontically treated with inlay cavities prepared and restored with indirect composite inlay restorations; the third group (n = 15) was also endodontically treated with onlay cavities prepared and restored with indirect composite onlay restorations; and the fourth group (n = 10) was endodontically treated with mesio-occlusodistal (MOD) cavities prepared and left unrestored to serve as negative controls. Dual cure indirect composite resin was used to fabricate the inlay and onlay restorations performed for the second and third groups, respectively. All teeth were subjected to compressive axial loading test using a metal ball (6 mm in diameter) in a universal testing machine (Instron 1195) with a cross-head speed of 0.5 mm/min until a fracture occurred. Statistical analysis of fracture resistance and fracture mode were performed with analysis of variance (ANOVA) (α = 0.05) and Kruskal–Wallis (α = 0.05) tests, respectively. Results For the four treatment groups, the mean fracture resistance values were 1326.9 N, 1500.1 N, 1006.1 N, and 702.7 N, respectively. Statistical analyses showed no significant differences between the mean fracture resistance of the intact tooth group and the inlay restoration group (p > 0.05), while significant differences were observed between the mean fracture resistance of all the other groups (p inlay and onlay restorations. However, the fractures that accompanied the inlay restorations were more severe and were unable to be restored. PMID:26792970

  18. Preparing and Restoring Composite Resin Restorations. The Advantage of High Magnification Loupes or the Dental Surgical Operating Microscope.

    Science.gov (United States)

    Mamoun, John

    2015-01-01

    Use of magnification, such as 6x to 8x binocular surgical loupes or the surgical operating microscope, combined with co-axial illumination, may facilitate the creation of stable composite resin restorations that are less likely to develop caries, cracks or margin stains over years of service. Microscopes facilitate observation of clinically relevant microscopic visual details, such as microscopic amounts of demineralization or caries at preparation margins; microscopic areas of soft, decayed tooth structure; microscopic amounts of moisture contamination of the preparation during bonding; or microscopic marginal gaps in the composite. Preventing microscope-level errors in composite fabrication can result in a composite restoration that, at initial placement, appears perfect when viewed under 6x to 8x magnification and which also is free of secondary caries, marginal staining or cracks at multi-year follow-up visits.

  19. Longevity of posterior composite restorations: A systematic review and meta-analysis

    DEFF Research Database (Denmark)

    Opdam, Niek; van de Sande, Francoise; Bronkhorst, Ewald;

    2014-01-01

    The aim of this meta-analysis, based on individual participant data of several studies, was to investigate the influence of patient, materials and tooth related variables on the survival of posterior resin composite restorations. Methods: Following PRISMA guidelines a search was conducted resulting...... in 12 longitudinal studies of direct posterior resin composite restorations with at least 5 years follow-up. Original datasets were still available, including placement/failure/censoring of restorations, restored surfaces, materials used, reasons for clinical failure, and caries-risk status. A database...... including all restorations was constructed and a Multivariate Cox’s regression method was used to analyze variables of interest [patient (age; gender; caries-risk-status), jaw (upper; lower), number of restored surfaces, resin composite and adhesive materials and use of glass-ionomer cement as base...

  20. 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.

  1. Multispectral Near-Infrared Imaging of Composite Restorations in Extracted Teeth

    OpenAIRE

    Logan, Cooper M.; Co, Katrina U.; Fried, William A.; Simon, Jacob C.; Staninec, Michal; and, Daniel Fried; Darling, Cynthia L.

    2014-01-01

    One major advantage of composite restoration materials is that they can be color matched to the tooth. However, this presents a challenge when composites fail and they need to be replaced. Dentists typically spend more time repairing and replacing composites than placing new restorations. Previous studies have shown that near-infrared imaging can be used to distinguish between sound enamel and decay due to the differences in light scattering. The purpose of this study was to use a similar app...

  2. Effects of Fiber-reinforced Composite Bases on Microleakage of Composite Restorations in Proximal Locations

    Science.gov (United States)

    A, Tezvergil-Mutluay; P.K, Vallittu

    2014-01-01

    Objectives: The aim of this study was to evaluate the microleakage of direct restorative composite resin upon the addition of an intermediate glass fiber-reinforced composite (GFRC) layer of various fiber orientations between tooth and particulate filler composite resin (PFRC). Materials and Methods: Cavities were prepared both on the mesial and distal surfaces of sixty extracted human molars with one margin placed below and the other above the cementoenamel junction (CEJ). Teeth were assigned to five different groups. Four of the groups received a layer of semi-interpenetrating polymer network (semi-IPN) resin system impregnated E-glass GFRC at the bottom of the cavity: Group 1; unidirectional continuous GFRC (EVS) in buccolingual direction (EVS-BL), Group 2; EVS in mesiodistal direction (EVS-MD), Group 3; bidirectional woven GFRC (EVN), Group 4; multidirectional short GFRC (EXP-MLT), Group 5; PRFC only (control). After acid etching and priming of the cavities and insertion of GFRC layer with the adhesive resin (Scotchbond Multipurpose 3M-ESPE), the cavities were filled incrementally with PRFC (Filtek Z250, 3M-ESPE) and each layer was light cured for 20 s. After finishing and polishing, the restored teeth were water-stored for 24 h at 37 °C and then thermocycled for 6000 cycles between 5-55 °C, before immersion in 0.5 % basic fuchsin dye for 24 h. After sectioning by 3-5 sagittal cuts, each sequential section was imaged and digitally analyzed to determine the stain depth. Results: All GFRC groups in dentin revealed significantly lower microleakage compared to control (p0.05). The microleakeage in enamel was not different between the groups (p>0.05). Conclusion: Use of intermediate GFRC layer between tooth and PFRC could provide alternative method to minimize microleakage. Clinical Relevance: Use of GFRC intermediate layer underneath the particulate filler composite can be used to minimize the leakeage of the restorations. PMID:25512764

  3. 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

    Summary Aim To determine and compare the fracture resistance of endodontically treated teeth restored with a bulk fill flowable material (SDR) and a traditional resin composite. Methods Thirty maxillary and 30 mandibular first molars were selected based on similar dimensions. After cleaning, shaping and filling of the root canals and adhesive procedures, specimens were assigned to 3 subgroups for each tooth type (n=10): Group A: control group, including intact teeth; Group B: access cavities were restored with a traditional resin composite (EsthetX; Dentsply-Italy, Rome, Italy); Group C: access cavities were restored with a bulk fill flowable composite (SDR; Dentsply-Italy), except 1.5 mm layer of the occlusal surface that was restored with the same resin composite as Group B. The specimens were subjected to compressive force in a material static-testing machine until fracture occurred, the maximum fracture load of the specimens was measured (N) and the type of fracture was recorded as favorable or unfavorable. Data were statistically analyzed with one-way analysis of variance (ANOVA) and Bonferroni tests (Pcomposite and with a bulk fill flowable composite (SDR) was similar in both maxillary and mandibular molars and showed no significant decrease in fracture resistance compared to intact specimens. Conclusions 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. PMID:27486505

  4. Comparative evaluation of combined amalgam and composite resin restorations in extensively carious vital posterior teeth: An in vivo study

    OpenAIRE

    Gagandeep Kaur; Manpreet Singh; C S Bal; Singh, U. P.

    2011-01-01

    Aim : The clinical performance of the combined composite - amalgam restorations in posterior teeth was evaluated. Materials and Methods : One hundred carious posterior teeth were randomly divided into four groups of 25 teeth each. In Group A, the teeth were restored with composite Z250 and amalgam FusionAlloy. In Group B, composite Surefil and amalgam were used. In Groups C and D, the teeth were restored with composite Surefil and amalgam FusionAlloy, respectively. The restorations were ...

  5. Comparative evaluation of combined amalgam and composite resin restorations in extensively carious vital posterior teeth: An in vivo study

    OpenAIRE

    Kaur, Gagandeep; Singh, Manpreet; Bal, CS; Singh, UP

    2011-01-01

    Aim: The clinical performance of the combined composite – amalgam restorations in posterior teeth was evaluated. Materials and Methods: One hundred carious posterior teeth were randomly divided into four groups of 25 teeth each. In Group A, the teeth were restored with composite Z250 and amalgam FusionAlloy. In Group B, composite Surefil and amalgam were used. In Groups C and D, the teeth were restored with composite Surefil and amalgam FusionAlloy, respectively. The restorations were evaluat...

  6. Posterior composite restoration update: focus on factors influencing form and function

    Directory of Open Access Journals (Sweden)

    Bohaty BS

    2013-05-01

    Full Text Available Brenda S Bohaty,1,2 Qiang Ye,3 Anil Misra,3,4 Fabio Sene,6 Paulette Spencer3,51Department of Pediatric Dentistry, University of Missouri-Kansas City School of Dentistry, Kansas City, MO, USA; 2Department of Pediatric Dentistry, Children's Mercy Hospital, Kansas City, MO, USA; 3Bioengineering Research Center, 4Department of Civil, Environmental, and Architectural Engineering, 5Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA; 6Department of Restorative Dentistry, State University of Londrina, School of Dentistry, Londrina, BrazilAbstract: Restoring posterior teeth with resin-based composite materials continues to gain popularity among clinicians, and the demand for such aesthetic restorations is increasing. Indeed, the most common aesthetic alternative to dental amalgam is resin composite. Moderate to large posterior composite restorations, however, have higher failure rates, more recurrent caries, and increased frequency of replacement. Investigators across the globe are researching new materials and techniques that will improve the clinical performance, handling characteristics, and mechanical and physical properties of composite resin restorative materials. Despite such attention, large to moderate posterior composite restorations continue to have a clinical lifetime that is approximately one-half that of the dental amalgam. While there are numerous recommendations regarding preparation design, restoration placement, and polymerization technique, current research indicates that restoration longevity depends on several variables that may be difficult for the dentist to control. These variables include the patient's caries risk, tooth position, patient habits, number of restored surfaces, the quality of the tooth–restoration bond, and the ability of the restorative material to produce a sealed tooth–restoration interface. Although clinicians tend to focus on tooth form when evaluating the success and failure of

  7. SEM evaluation of marginal sealing on composite restorations using different photoactivation and composite insertion methods

    Directory of Open Access Journals (Sweden)

    Lopes Murilo

    2009-01-01

    Full Text Available Aim: This in vitro study evaluates the influence of marginal sealing methods in composite restorations with different adhesive systems submitted to mechanical load. Materials and Methods: Eighty bovine incisor crowns were embedded in Polyvinyl chloride (PVC molds with the buccal surface exposed, where cavities (4mm x 4mm x 3mm were made. Samples had the adhesive systems, Single Bond or Clearfil SE Bond, applied according to the manufacturer′s recommendations. The cavities were filled with a Z-250 composite according to the restoration technique (bulk filling or three increments and photoactivation (conventional, soft start, pulsatile light or light-emitting diode [LED]. The samples were duplicated with epoxy resin for scanning electron microscopy observations. Samples were also submitted to mechanical load (200,000 cycles; 2 Hz and new replicas were made. Results: The results, in percentages, were submitted to ANOVA followed by Tukey′s test (P < 0.05. There was statistical difference between the cycle group (23.84% and the non cycle group (18.63%. Comparing the restoration technique, there was no statistical difference between bulk filling (19.62% and three increments (22.84%. There was no statistical difference among the groups: Pulsatile light (24.38%, soft start (22.75%, LED (21.47% or conventional (16.34%. Furthermore, there were no statistical differences between the adhesive systems: Clearfil SE Bond (21.32% and Single Bond (20.83%. Conclusions: The photoactivation methods, the restorative techniques and the adhesive systems did not influence gap formation.

  8. Effect of enamel margin configuration on color change of resin composite restoration.

    Science.gov (United States)

    Aida, Asami; Nakajima, Masatoshi; Seki, Naoko; Kano, Yukinori; Foxton, Richard M; Tagami, Junji

    2016-01-01

    This study aimed to investigate the effect of enamel margin configuration on color change of resin composite restoration. Enamel disks of 1.0 mm-thick were sliced from sixty bovine anterior teeth and divided into three groups by margin configuration (non-bevel, 45-degree bevel and 45-degree reverse-bevel). The color measurements (L*C*h* values) at the restored bovine enamel disk with resin composite (Estelite Asteria, Estelite Pro, Kalore, Clearfil Majesty) were performed using a digital camera with CIE XYZ color gamut (RC500). All the resin composite restorations with non-beveled and beveled cavities significantly increased L* values compared with the control composite disks (presin composite restoration and color adjustment of the border.

  9. The direct posterior esthetic restoration using state-of-the-art composite resin technology.

    Science.gov (United States)

    Pescatore, C

    2000-01-01

    As a result of the evolution of both materials and techniques, the direct posterior composite restoration has become a common procedure in today's dental practice. Advances in the adhesive protocol have allowed for the conservative preparation of the dentition by using the micromechanical potential of the sound tooth structure. Improvements of composite resin materials have further enabled the practitioner to re-create the natural esthetic beauty of the dentition while at the same time restoring the functional morphology. This article describes the technical protocol and materials necessary to perform the direct posterior composite restoration in the posterior dentition.

  10. THE MANUFACTURING OF COLD STEEL REINFORCEMENT CLASS V55OA STANDARD ONÖRM B 4707:2010

    Directory of Open Access Journals (Sweden)

    T. A. Akhmetov

    2013-01-01

    Full Text Available The manufacturing technology for wire rod with an optimized chemical composition was developed. It allows to produce reinforced steel class V550A in accordance with the requirements of ONORM B 4707:2010 taking into account changes its quality characteristics after mechanical changes and certify these products on the standard.

  11. Blending incremental and stratified layering techniques to produce an esthetic posterior composite resin restoration with a predictable prognosis.

    Science.gov (United States)

    Klaff, D

    2001-01-01

    Composite resin restorations play an ever-increasing role as routine restorations in everyday clinical practice. However, the long-term prognosis of these restorations is still widely debated and open to question. The restorative protocols are still evolving, whether for direct or indirect placement, and little evidence is available in the scientific literature as to the ideal choice of site, technique, and category for placement. This article discusses the problems encountered and suggests a clinical restorative protocol to optimize composite resin placement.

  12. In vitro repair of fractured fiber-reinforced cusp-replacing composite restorations

    NARCIS (Netherlands)

    Fennis, W.M.M.; Kreulen, C.M.; Tezvergil, A.; Lassila, L.V.; Vallittu, P.K.; Creugers, N.H.J.

    2011-01-01

    Objective. To assess fracture resistance and failure mode of repaired fiber-reinforced composite (FRC) cusp-replacing restorations. Methods. Sixteen extracted human premolars with fractured cusp-replacing woven (Group (A)) or unidirectional (Group (B)) FRC restorations from a previous loading experi

  13. 18-year survival of posterior composite resin restorations with and without glass ionomer cement as base.

    NARCIS (Netherlands)

    Sande, F.H. van de; Rosa Rodolpho, P.A. Da; Basso, G.R.; Patias, R.; Rosa, Q.F. da; Demarco, F.F.; Opdam, N.J.M.; Cenci, M.S.

    2015-01-01

    OBJECTIVE: Advantages and disadvantages of using intermediate layers underneath resin-composite restorations have been presented under different perspectives. Yet, few long-term clinical studies evaluated the effect of glass-ionomer bases on restoration survival. The present study investigated the i

  14. Diagnostic value of DIAGNOdent in detecting caries under composite restorations of primary molars

    Directory of Open Access Journals (Sweden)

    Ava Vali Sichani

    2016-01-01

    Conclusion: DIAGNOdent showed a greater accuracy in detecting secondary caries under primary molar restorations, compared to radiographs. Although DIAGNOdent is an effective method for detecting caries under composite restorations, it is better to be used as an adjunctive method alongside other detecting procedures.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  16. 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

    three (one set) as similar as possible Class II restorations of moderate size.After cavity preparation, the three cavities were chosen at random to be restored with twochemical-cured (P10, Miradapt) and one light-cured resin composite (P30). A chemical-curedenamel bonding agent was applied after etching...

  17. Interactions between cavity preparation and restoration events and their effects on pulp vitality.

    Science.gov (United States)

    Wisithphrom, Kessiri; Murray, Peter E; About, Imad; Windsor, L Jack

    2006-12-01

    The purpose of this study was to investigate the precise effect and rank the importance of cavity preparation and restoration variables on human pulp vitality. Fifty-three Class V unexposed cavities were prepared and restored with calcium hydroxide/amalgam, resin-modified glass ionomer, zinc oxide-eugenol, resin composite, or zinc polycarboxylate materials. Pulp vitality was reduced by the remaining dentin thickness of the cavity preparations, whereas the other variables, including the type of restorative material, had little effect. Restorative materials cause minimal pulp damage in isolation; it is more important to minimize the removal of intact dentin to maintain the vitality of teeth.

  18. Class II direct composite resin restorations with beta-quartz glass-ceramic inserts.

    Science.gov (United States)

    Rada, R E

    1993-11-01

    With the increasing demand for esthetic posterior restorations, numerous techniques have been developed. The direct resin restoration has probably been used most extensively in Class II situations. Problems with Class II direct resin restorations include difficulty in developing proximal contact, occlusal wear, and polymerization shrinkage. Beta-quartz glass-ceramic inserts have been developed in an attempt to reduce the incidence of these potential problems. They can be placed in a one-appointment technique, are relatively inexpensive, and can readily be utilized by the clinician adept in placing Class II composite resin restorations.

  19. Effect of the number of thermocycles on microleakage of resin composite restorations

    Directory of Open Access Journals (Sweden)

    Pazinatto Flávia Bittencourt

    2003-01-01

    Full Text Available Thermocycling simulates, in vitro, thermal changes that occur in the oral cavity. The aim of this study was to evaluate the influence of the number of cycles on microleakage. Class V cavities (1.5 mm deep, 3 mm in height and 3 mm in width were prepared in bovine teeth, restored with a Single Bond/Z250 restorative system (3M/ESPE and then divided into five groups of ten teeth each: group 1 was not thermocycled (control group, and groups 2, 3, 4 and 5 were thermocycled 500, 1,000, 2,500 and 5,000 times, respectively (5º-55º ± 2ºC, 15 s dwell time. The teeth were immersed in 0.5% basic fuchsin aqueous solution for 24 h, sectioned and the sections with the highest degree of microleakage were selected, scanned and the extent of dye penetration was measured by the ImageTool program. The results submitted to one-way ANOVA showed no significant differences between the groups (p > 0.05. The averages of microleakage values in millimeters were: group 1 (3.92; group 2 (3.13; group 3 (4.48; group 4 (4.33 and group 5 (3.42. Thus, it was concluded that there is no relation between the increase of the number of cycles and the increase in microleakage.

  20. 56-month clinical performance of Class I and II resin composite restorations

    Directory of Open Access Journals (Sweden)

    Flavia Bittencourt Pazinatto

    2012-06-01

    Full Text Available OBJECTIVE: This study evaluated the 56-month clinical performance of Class I and II resin composite restorations. Filtek P60 was compared with Filtek Z250, which are both indicated for posterior restorations but differ in terms of handling characteristics. The null hypothesis tested was that there is no difference in the clinical performance of the two resin composites in posterior teeth. MATERIAL AND METHODS: Thirty-three patients were treated by the same operator, who prepared 48 Class I and 42 Class II cavities, which were restored with Single Bond/Filtek Z250 or Single Bond/Filtek P60 restorative systems. Restorations were evaluated by two independent examiners at baseline and after 56 months, using the modified USPHS criteria. Data were analyzed statistically using Chi-square and Fisher's Exact tests (a=0.05. RESULTS: After 56 months, 25 patients (31 Class I and 36 Class II were analyzed. A 3% failure rate occurred due to secondary caries and excessive loss of anatomic form for P60. For both restorative systems, there were no significant differences in secondary caries and postoperative sensitivity. However, significant changes were observed with respect to anatomic form, marginal discoloration, and marginal adaptation. Significant decreases in surface texture were observed exclusively for the Z250 restorations. CONCLUSIONS: Both restorative systems can be used for posterior restorations and can be expected to perform well in the oral environment.

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

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2015-01-01

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

  2. 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.

  3. Bonding performance and interfacial characteristics of short fiber-reinforced resin composite in comparison with other composite restoratives.

    Science.gov (United States)

    Tsujimoto, Akimasa; Barkmeier, Wayne W; Takamizawa, Toshiki; Latta, Mark A; Miyazaki, Masashi

    2016-06-01

    The purpose of this study was to investigate the shear bond strength (SBS) and surface free-energy (SFE) of short fiber-reinforced resin composite (SFRC), using different adhesive systems, in comparison with other composite restoratives. The resin composites used were everX Posterior (EP), Clearfil AP-X (CA), and Filtek Supreme Ultra Universal Restorative (FS). The adhesive systems used were Scotchbond Multi-Purpose (SM), Clearfil SE Bond (CS), and G-Premio Bond (GB). Resin composite was bonded to dentin, and SBS was determined after 24 h of storage in distilled water and after 10,000 thermal cycles (TCs). The SFEs of the resin composites and the adhesives were determined by measuring the contact angles of three test liquids. The SFE values and SFE characteristics were not influenced by the type of resin composite, but were influenced by the type of adhesive system. The results of this study suggest that the bonding performance and interfacial characteristics of SFRC are the same as for other composite restoratives, but that these parameters are affected by the type of adhesive system. The bonding performance of SFRC was enhanced by thermal cycling in a manner similar to that for other composite restoratives.

  4. Microleakage of Composite Resin Restorations Using a Type of Fifth and Two Types of Seventh Generations of Adhesive Systems: A Comparative Study

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    Mitra Tabari

    2015-12-01

    Full Text Available Introduction: In recent dentin adhesive systems etching of enamel/dentin are achieved simultaneously. The objective was to evaluate the microleakage of composite restorations using Single Bond2 (5th generation, Clearfil S3 Bond and G Bond (7th generation. Methods: Class V cavities were prepared on  45 extracted intact premolars with gingival margins at the cementoenamel junction and they were randomly divided into 3 groups (n=15 based on the type of adhesives: Single Bond2 (5th generation, Clearfil S3 Bond and G Bond (7th generation. After applying the adhesives, the cavities were filled with Z250 composite resin. The occlusal and gingival microleakage was evaluated using 2% basic fuchsin staining technique. Data were analyzed using Kruskal-Wallis and Bonferroni corrected Mann-Whitney U tests. Results: The mean rank of occlusal microleakage exhibited significant differences by comparison of G Bond, Clearfil S3 Bond and Single Bond2 (21.07, 30.67 and 17.27, respectively (P=0.005. There was a significant difference in gingival microleakage of different bonding agents (34.40, 17.83 and 16.77 for G Bond, Clearfil S3 Bond and Single Bond2, respectively (P

  5. Simplified techniques for the placement of stratified polychromatic anterior and posterior direct composite restorations.

    Science.gov (United States)

    Blank, Jeff T

    2003-02-01

    Although many tooth-colored indirect restorative materials are available, dentists frequently employ direct composite resins as a primary tooth-colored restorative material. Direct resin systems that are suited for stratification, or layering of various opacities and colors of dental composite, offer dentists the opportunity to accurately reproduce natural teeth in ways that rival the esthetics of most indirect systems. This article presents a simplified version of the classical three-layered technique originally described by Dietschi, and demonstrates the application of a recently introduced composite resin system.

  6. Resistance of Bonded Composite Restorations on Fractures of Endodontically Treated Teeth

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    AR Daneshkazemi

    2005-01-01

    Full Text Available Introduction: This study was performed to evaluate the effect of dentine bonding agents and Glass Ionomer cement beneath composite restorations and its resistance on fractures of endodontically treated teeth. Material and Methods: Forty sound maxillary teeth were selected; ten of them for positive control, and on the rest, RCT and MOD cavity preparations were done with standard methods. Then, the teeth were divided to four groups: 1-Sound teeth for positive control. 2-Prepared without any restoration for negative control. 3-Prepared and restored with Vitrabond(3M, USA, Single bond(3M, USA and Z100(3M, USA resin composite. 4-Prepared and restored by Single bond and Z100 resin composite. Specimens were subjected to compressive load by Instron 8502 until fracture occurred. Results: Group 1 showed the highest resistance to compressive forces followed by group 4,3&2 respectively. ANOVA, t test and Chi-square tests indicated significant difference between all the groups. Conclusion: Use of dentine bonding agents and resin composite increases resistance of endodontically treated teeth to fractures more than teeth restored with sandwich of glass ionomer cements, dentine bonding agents and resin composite.

  7. A study of composite restorations as a tool in forensic identification

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    Bahavathi Ananthan Hemasathya

    2013-01-01

    Full Text Available Introduction: Comparing ante-mortem and post-mortem dental data is a principal method of identification in forensic odontology. Radiographic images of amalgam have been used in dental forensics for identification due to their unique appearance. Aim: The aim of this study was to investigate whether radio-opaque composite restorations have a potential for identification in forensic odontology. Materials and Methods: Thirty typodont mandibular first molar teeth were prepared with Class-II (proximo-occlusal cavities and restored with a radio-opaque composite (Tetric N-Ceram. Two sets of standardized radiographs were taken from the 30 teeth, keeping the radiological parameters constant. One set of these 30 radiographs was named as SET 1. Ten randomly chosen radiographs from the other set and two other radiographs of Class-II composite restorations in typodont teeth constituted SET 2. Thirty dentally trained examiners were asked to match the 12 radiographic images of SET 2 with those of SET 1. Results: The results show that 15 examiners were able to correctly match all the 12 images. Statistical analysis was done using kappa statistical test. Conclusion: This study shows that, if the post-mortem radiographs are accurate duplicates of ante-mortem radiographs of composite restorations, then the shape of the composite restoration is unique and can be used for identification.

  8. A comparison of microhardness of indirect composite restorative materials

    DEFF Research Database (Denmark)

    Miranda, Carolina Baptista; Pagani, Clóvis; Bottino, Marco Cícero;

    2003-01-01

    indicate that distinct mechanical properties may be observed at specific materials. The composition of each material as well as variations on polymerization methods are possibly responsibles for the difference found in microhardness. Therefore, indirect composite resin materials that guarantee both good...

  9. Microleakage of Posterior Composite Restorations with Fiber Inserts Using two Adhesives after Aging

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    Sharafeddin F.

    2013-09-01

    Full Text Available Statement of Problem: Microleakage is one of the most frequent problems associated with resin composites, especially at the gingival margin of posterior restorations. Inser-tion of fibers in composite restorations can reduce the total amount of composite and help to decrease the shrinkage.Purpose: The aim of this study was to evaluate the effect of polyethylene fiber inserts on gingival microleakage of class II composite restorations using two different adhe-sive systems.Materials and Method: In this experimental study, class II cavities were prepared on 60 premolars. The gingival floor was located 1.0 mm below the CEJ. Dimension of each cavity were 3 mm buccolingually and 1.5 mm in axial depth. The specimens were divided into 4 groups according to the adhesive type and fiber insert (n=4. Single bond and Clearfill SE bond and Filtek p60 were used to restore the cavities. In groups without fiber inserts composite was adapted onto cavities using layering technique. For cavities with fiber inserts, 3 mm piece of fiber insert was placed onto the composite increment and cured. The specimens were stored in distilled water at 37oC for 6 months. All specimens were subjected to 3000 thermo-cycling. The tooth surfaces except for 1 mm around the restoration margins covered with two layers of nail varnish .The teeth were immersed in 2% Basic Fuchsin for 24 hours, then rinsed and sectioned mesiodistally. The microleakage was determined under a stereomicroscope (40X. Data were statistically analyzed by Kruskal-wallis and Mann-Whitney U tests (p< 0.05.Results: The Kruskal-Wallis test revealed no significant differences in mean microlea-kage scores among all groups (p= 0.281.Conclusion: Use of polyethylene fiber inserts and etch-and-rinse and self-etch adhesives had no effect on microleakage in class II resin composite restorations with gingival margins below the CEJ after 6- month water storage.

  10. Effect of Precuring Warming on Mechanical Properties of Restorative Composites

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    Kareem Nada

    2011-01-01

    Full Text Available To investigate the effect of prepolymerization warming on composites' mechanical properties, three composites were evaluated: Clearfil Majesty (CM (Kuraray, Z-100 (3M/ESPE, and Light-Core (LC (Bisco. Specimens were prepared from each composite at room temperature as control and 2 higher temperatures (37∘C and 54∘C to test surface hardness (SH, compressive strength (CS, and diametral tensile strength (DTS. Data were statistically analyzed using ANOVA and Fisher's LSD tests. Results revealed that prewarming CM and Z100 specimens significantly improved their SH mean values (P<0.05. Prewarming also improved mean CS values of Z100 specimens (P<0.05. Furthermore, DTS mean value of CM prepared at 52∘ was significantly higher than that of room temperature specimens (P<0.05. KHN, CS, and DTS mean values varied significantly among the three composites. In conclusion, Prewarming significantly enhanced surface hardness of 2 composites. Prewarming also improved bulk properties of the composites; however, this improvement was significant in only some of the tested materials.

  11. 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.

  12. Clinical Studies: What do they tell us about direct posterior composite restorations?

    DEFF Research Database (Denmark)

    Pallesen, Ulla

    Within the last 25 years composite resin materials have in many countries successively replaced amalgam as a restorative for posterior teeth. Resin materials and bonding systems are continuously being improved by the manufactures, adhesive procedures are now included in the curriculum of most uni...... and results from own up to 30-year prospective clinical university studies and practice based studies from Public Dental Health Service on the clinical performance of posterior composite resin restorations.......Within the last 25 years composite resin materials have in many countries successively replaced amalgam as a restorative for posterior teeth. Resin materials and bonding systems are continuously being improved by the manufactures, adhesive procedures are now included in the curriculum of most...... universities and practicing dentists restore millions of teeth throughout the World with composite resin materials. Do we know enough about the clinical performance of these restorations over time? Numerous in vitro studies are being published on resin materials and adhesion, some of them attempting to imitate...

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

    Science.gov (United States)

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

    2015-01-01

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

  14. Marginal and internal fit of nano-composite CAD/CAM restorations

    OpenAIRE

    Park, So-Hyun; Yoo, Yeon-Jee; Shin, Yoo-Jin; Cho, Byeong-Hoon; Baek, Seung-Ho

    2016-01-01

    Objectives The purpose of this study was to compare the marginal and internal fit of nano-composite CAD-CAM restorations. Materials and Methods A full veneer crown and an mesio-occluso-distal (MOD) inlay cavity, which were prepared on extracted human molars, were used as templates of epoxy resin replicas. The prepared teeth were scanned and CAD-CAM restorations were milled using Lava Ultimate (LU) and experimental nano-composite CAD/CAM blocks (EB) under the same milling parameters. To assess...

  15. PIXE and ERDA analysis of composites for restorative dentistry

    International Nuclear Information System (INIS)

    Dental composites, made of silicates and oxides particles embedded in an organic polymer, replaced largely silver amalgam in dentistry. However they bring in the organism exogenous elements whose biological action is poorly understood. In the mouth element transfer and reactions can take place leading eventually to adverse effects of dental composites. Due to market pressure composites show a dynamic evolution, but they are rather expensive. Recently, Romanian biomaterials offered a low-cost alternative, and control of impurities appeared clinically essential. Sensitive surface multielement analysis required for these problems is rendered by ion beam methods. Particle-induced X-ray emission (PIXE) was used in studies of dental hard tissues and composites. Though highly sensitive for trace elements, PIXE usually fails to observe low Z elements. These can be detected by elastic recoil detection analysis (ERDA). We applied PIXE and ERDA in a study on dental composites at the 8.5 MV HIPNE-HH tandem accelerator. Thick composite samples with a flat surface were prepared by polymerization of 14 commercial materials and of 3 Romanian products. Measurements were performed with: 3 MeV protons, a HP Ge detector, and using 0 or 30 mm Al foil for PIXE; and with 80 MeV 63 Cu10+ ions, using a compact DE(gas)-E(solid) telescope detector for ERDA. Altogether, PIXE spectra evidenced up to 24 elements with Z > 16 (Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Y, Zr, Nb, Ag, Cd, Ba, Nd, Ho, Yb, Hf, Au, Pb, many of them at trace levels), while ERDA detected up to 13 elements with Z < 21 (H, B, C, N, O, F, Na, Al, Si, P, Cl, K, Ca). Relative concentrations evaluated from the PIXE spectra using X-ray yields calculated for a simplified matrix allowed classification of the 14 biomaterials in two distinct groups: older generations dominated by Z = 17 - 30 elements and recent generations containing one or two elements such as Sr, Zr, Ba, Yb (plus Ca in some cases). Composites with close

  16. Considerations regarding the optical properties of the composite resin restorative materials.

    Science.gov (United States)

    Manolea, H; Râcă, R; Coleş, Evantia; Preotu, Gabriela; Mărăşescu, P

    2011-07-01

    The purpose of this study has been to investigate the effects of certain substances frequently used in alimentation on the color stability of the composite resin restorative materials. The research hypothesis was that color stability of the composite resin is affected by the type of composite material used and by the polishing procedure. 14 samples of 5X15X2mm have been prepared from seven universal light curing restorative composite resins. The materials have manipulated and cured using LA 500 Blue Light lamp. A first color determination was done before the introduction of the samples in the dyeing agent with the help of an Easy Shade device. The samples have been splited into two lots each with seven samples. The samples from the first lot have been sectioned into three equal segments. The samples from the second lot have also been sectioned into three equal segments, and in addition to the previous group, their exterior surfaces were processed with a diamond burr. For each type of composite we have introduced a sample in one of the three chosen dyes: red alimentary colorant, coffee and red wine. The color of the samples has been determined again using the Vita Easy Shade device. From clinical point of view the results of this study shows that there are three important factors that matter when we talk about durable aesthetic results: the type of composite resin used for the restoration, the finishing and polishing procedures and the pacients' alimentation habits. The composite resins with a good representation of the anorganic structure are easier to be polished, therefore they have only slight color modifications. Using plastic matrixes for shaping the exterior surface of the restoration is the best solution for obtaining a very smooth surface. The most significant color modifications have been done by the red wine. Coffee and to a smaller extent the red alimentary colorant have modified the color of the restoration material in a smaller degree. PMID:24778835

  17. Behaviour of general dental practitioners in Germany regarding posterior restorations with flowable composites.

    Science.gov (United States)

    Seemann, Rainer; Pfefferkorn, Frank; Hickel, Reinhard

    2011-10-01

    Because the recommendation to use flowables for posterior restorations is still a matter of debate, the objective of this study was to determine in a nationwide survey in Germany how frequently, for what indications, and for what reasons, German dentists use flowable composites in posterior teeth. In addition, the acceptance of a simplified filling technique for posterior restorations using a low stress flowable composite was evaluated. Completed questionnaires from all over Germany were returned by 1,449 dentists resulting in a response rate of 48.5%; 78.6% of whom regularly used flowable composites for posterior restorations. The most frequent indications were cavity lining (80.1%) and small Class I fillings (74.2%). Flowables were less frequently used for small Class II fillings (22.7%) or other indications (13.6%). Most frequent reasons given for the use of flowables in posterior teeth were the prevention of voids (71.7%) and superior adaptation to cavity walls (72.9%), whereas saving time was considered less important (13.8%). Based on the subjective opinion of the dentists the simplified filling technique seemed to deliver advantages compared to the methods used to date particularly with regard to good cavity adaptation and ease of use. In conclusion, resin composites are the standard material type used for posterior restorations by general dental practitioners in Germany and most dentists use flowable composites as liners.

  18. Comparison of fracture resistance of teeth restored with ceramic inlay and resin composite: An in vitro study

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    Priti D Desai

    2011-01-01

    Conclusion: The fracture resistant strength of teeth restored with ceramic inlay was comparable to that of the normal intact teeth or slightly higher, while teeth restored with direct composite resin restoration showed less fracture resistant strength than that of the normal teeth.

  19. In Vitro Repair of Fractured Fiber-Reinforced Cusp-Replacing Composite Restorations

    Directory of Open Access Journals (Sweden)

    Willem M. M. Fennis

    2011-01-01

    Full Text Available Objective. To assess fracture resistance and failure mode of repaired fiber-reinforced composite (FRC cusp-replacing restorations. Methods. Sixteen extracted human premolars with fractured cusp-replacing woven (Group (A or unidirectional (Group (B FRC restorations from a previous loading experiment were repaired with resin composite and loaded to fracture. Results. Differences in fracture loads between groups were not statistically significant (P=0.34. Fracture loads of repaired specimens were significantly lower than those of original specimens (P=0.02 for Group (A and P<0.001 for Group (B. Majority of specimens showed failure along the repaired surface. In Group (B 89% of specimens showed intact tooth substrate after restoration fracture, while this was 28% in Group (A (P=0.04. Conclusion. Fractured cusp-replacing FRC restorations that are repaired with resin composite show about half of fracture resistance of original restorations. Mode of failure with a base of unidirectional fibers is predominantly adhesive.

  20. Selective removal of esthetic composite restorations with spectral guided laser ablation

    Science.gov (United States)

    Yi, Ivana; Chan, Kenneth H.; Tsuji, Grant H.; Staninec, Michal; Darling, Cynthia L.; Fried, Daniel

    2016-02-01

    Dental composites are used for a wide range of applications such as fillings for cavities, adhesives for orthodontic brackets, and closure of gaps (diastemas) between teeth by esthetic bonding. Anterior restorations are used to replace missing, diseased and unsightly tooth structure for both appearance and function. When these restorations must be replaced, they are difficult to remove mechanically without causing excessive removal or damage to enamel because dental composites are color matched to teeth. Previous studies have shown that CO2 lasers have high ablation selectivity and are well suited for removal of composite on occlusal surfaces while minimizing healthy tissue loss. A spectral feedback guidance system may be used to discriminate between dental composite and dental hard tissue for selective ablation of composite material. The removal of composite restorations filling diastemas is more challenging due to the esthetic concern for anterior teeth. The objective of this study is to determine if composite spanning a diastema between anterior teeth can be removed by spectral guided laser ablation at clinically relevant rates with minimal damage to peripheral healthy tissue and with higher selectivity than a high speed dental handpiece.

  1. Comparison of the marginal adaptation of direct and indirect composite inlay restorations with optical coherence tomography

    Science.gov (United States)

    TÜRK, Ayşe Gözde; SABUNCU, Metin; ÜNAL, Sena; ÖNAL, Banu; ULUSOY, Mübin

    2016-01-01

    ABSTRACT Objective The purpose of the study was to use the photonic imaging modality of optical coherence tomography (OCT) to compare the marginal adaptation of composite inlays fabricated by direct and indirect techniques. Material and Methods Class II cavities were prepared on 34 extracted human molar teeth. The cavities were randomly divided into two groups according to the inlay fabrication technique. The first group was directly restored on cavities with a composite (Esthet X HD, Dentsply, Germany) after isolating. The second group was indirectly restored with the same composite material. Marginal adaptations were scanned before cementation with an invisible infrared light beam of OCT (Thorlabs), allowing measurement in 200 µm intervals. Restorations were cemented with a self-adhesive cement resin (SmartCem2, Dentsply), and then marginal adaptations were again measured with OCT. Mean values were statistically compared by using independent-samples t-test and paired samples t-test (p<0.05), before and after cementation. Results Direct inlays presented statistically smaller marginal discrepancy values than indirect inlays, before (p=0.00001442) and after (p=0.00001466) cementation. Marginal discrepancy values were increased for all restorations after cementation (p=0.00008839, p=0.000000952 for direct and indirect inlays, respectively). The mean marginal discrepancy value of the direct group increased from 56.88±20.04 µm to 91.88±31.7 µm, whereas the indirect group increased from 107.54±35.63 µm to 170.29±54.83 µm. Different techniques are available to detect marginal adaptation of restorations, but the OCT system can give quantitative information about resin cement thickness and its interaction between tooth and restoration in a nondestructive manner. Conclusions Direct inlays presented smaller marginal discrepancy than indirect inlays. The marginal discrepancy values were increased for all restorations that refer to cement thickness after cementation

  2. Comparison of the marginal adaptation of direct and indirect composite inlay restorations with optical coherence tomography

    Science.gov (United States)

    TÜRK, Ayşe Gözde; SABUNCU, Metin; ÜNAL, Sena; ÖNAL, Banu; ULUSOY, Mübin

    2016-01-01

    ABSTRACT Objective The purpose of the study was to use the photonic imaging modality of optical coherence tomography (OCT) to compare the marginal adaptation of composite inlays fabricated by direct and indirect techniques. Material and Methods Class II cavities were prepared on 34 extracted human molar teeth. The cavities were randomly divided into two groups according to the inlay fabrication technique. The first group was directly restored on cavities with a composite (Esthet X HD, Dentsply, Germany) after isolating. The second group was indirectly restored with the same composite material. Marginal adaptations were scanned before cementation with an invisible infrared light beam of OCT (Thorlabs), allowing measurement in 200 µm intervals. Restorations were cemented with a self-adhesive cement resin (SmartCem2, Dentsply), and then marginal adaptations were again measured with OCT. Mean values were statistically compared by using independent-samples t-test and paired samples t-test (pinlays presented statistically smaller marginal discrepancy values than indirect inlays, before (p=0.00001442) and after (p=0.00001466) cementation. Marginal discrepancy values were increased for all restorations after cementation (p=0.00008839, p=0.000000952 for direct and indirect inlays, respectively). The mean marginal discrepancy value of the direct group increased from 56.88±20.04 µm to 91.88±31.7 µm, whereas the indirect group increased from 107.54±35.63 µm to 170.29±54.83 µm. Different techniques are available to detect marginal adaptation of restorations, but the OCT system can give quantitative information about resin cement thickness and its interaction between tooth and restoration in a nondestructive manner. Conclusions Direct inlays presented smaller marginal discrepancy than indirect inlays. The marginal discrepancy values were increased for all restorations that refer to cement thickness after cementation. PMID:27556210

  3. The Post-Amalgam Era: Norwegian Dentists’ Experiences with Composite Resins and Repair of Defective Amalgam Restorations

    OpenAIRE

    Kopperud, Simen E.; Frode Staxrud; Ivar Espelid; Anne Bjørg Tveit

    2016-01-01

    Amalgam was banned as a dental restorative material in Norway in 2008 due to environmental considerations. An electronic questionnaire was sent to all dentists in the member register of the Norwegian Dental Association (NTF) one year later, to evaluate dentists’ satisfaction with alternative restorative materials and to explore dentists’ treatment choices of fractured amalgam restorations. Replies were obtained from 61.3%. Composite was the preferred restorative material among 99.1% of the de...

  4. Esthetic integration between ceramic veneers and composite restorations: a case report

    OpenAIRE

    Farronato, Davide; Mangano, Francesco; Pieroni, Stefano; Giudice, Giuseppe Lo; Briguglio, Roberto; Briguglio, Francesco

    2012-01-01

    The tooth structure preservation is the best way to postpone more invasive therapies. Especially in young patients more conservative techniques should be applied. Bonded porcelain veneers and even more the direct composite restorations, are the two therapeutic procedures that require the fewer sacrifice of dental tissue, finalized to the optimal recovery of aesthetic and functional outcome.

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

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2016-01-01

    Objective: To evaluate in a randomized controlled study the 5-year clinical durability of a flowable resin composite bulk-fill technique in Class I and Class II restorations. Material and methods: 38 pairs Class I and 62 pairs Class II restorations were placed in 44 male and 42 female (mean age 52.......4 years). Each patient received at least two, as similar as possible, extended Class I or Class II restorations. In all cavities, a 1-step self-etch adhesive (Xeno V+) was applied. Randomized, one of the cavities of each pair received the flowable bulk-filled resin composite (SDR), in increments up to 4mm...... as needed to fill the cavity 2mm short of the occlusal cavosurface. The occlusal part was completed with the ormocer-based nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2mm increments. The restorations were evaluated using slightly...

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

    DEFF Research Database (Denmark)

    Dijken, Jan WVvan; Pallesen, Ulla

    2016-01-01

    OBJECTIVE: To evaluate in a randomized controlled study the 5-year clinical durability of a flowable resin composite bulk-fill technique in Class I and Class II restorations. MATERIAL AND METHODS: 38 pairs Class I and 62 pairs Class II restorations were placed in 44 male and 42 female (mean age 52.......4 years). Each patient received at least two, as similar as possible, extended Class I or Class II restorations. In all cavities, a 1-step self-etch adhesive (Xeno V+) was applied. Randomized, one of the cavities of each pair received the flowable bulk-filled resin composite (SDR), in increments up to 4mm...... as needed to fill the cavity 2mm short of the occlusal cavosurface. The occlusal part was completed with the nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2mm increments. The restorations were evaluated using slightly modified USPHS...

  7. Clinical cross-polarization optical coherence tomography assessment of subsurface enamel below dental resin composite restorations.

    Science.gov (United States)

    Lenton, Patricia; Rudney, Joel; Fok, Alex; Jones, Robert S

    2014-04-01

    A newly designed intraoral swept source cross-polarization optical coherence tomography (CP-OCT) imaging system was used to examine the integrity of the subsurface enamel below resin composite restorations placed in primary teeth. CP-OCT analysis was performed using images obtained from resin composite restoration in 62 ([Formula: see text]) pediatric subjects. Clinical examination was performed by a single examiner prior to CP-OCT imaging and analysis. CP-OCT images are presented using a unique combined intensity image, where a false color scale is overlaid on the grayscale intensity image. There was a clear difference in the distribution of the mean-backscattered intensity (mR) between restorations recently placed and those possessing frank cavitation (Student's t-test, [Formula: see text]). For mR above 15.49 dB, the sensitivity was 80% and specificity 86%. The Youden index J was 0.8 above 12.3 dB where sensitivity was 100% and specificity was 80%. CP-OCT imaging may be used to confirm the subsurface marginal integrity below resin composite restorations but with careful consideration of limitations of the imaging modality. CP-OCT imaging may be a useful adjunct to clinical visual investigation to confirm that a composite margin has a sound and well-adapted interface.

  8. A retrospective clinical study on longevity of posterior composite and amalgam restorations.

    NARCIS (Netherlands)

    Opdam, N.J.M.; Bronkhorst, E.M.; Roeters, F.J.M.; Loomans, B.A.C.

    2007-01-01

    OBJECTIVES: The purpose of this study was to evaluate retrospectively the longevity of class I and II amalgam and composite resin restorations placed in a general practice. METHODS: Patient records of a general practice were used for collecting the data for this study. From the files longevity and r

  9. 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.

  10. Effect of Static and Cyclic Loading on Ceramic Laminate Veneers Adhered to Teeth with and Without Aged Composite Restorations

    NARCIS (Netherlands)

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

    2011-01-01

    Purpose: Existing composite restorations on teeth are often remade prior to the cementation of fixed dental prostheses. The aim of this study was to evaluate the effect of static and cyclic loading on ceramic laminate veneers adhered to aged resin composite restorations. Materials and Methods: Eight

  11. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  12. Influence of matrix systems on proximal contact tightness of 2- and 3-surface posterior composite restorations in vivo

    NARCIS (Netherlands)

    Wirsching, E.; Loomans, B.A.C.; Klaiber, B.; Dorfer, C.E.

    2011-01-01

    OBJECTIVES: To investigate the influence of cavity preparation (MO/DO/MOD) and type of matrix system on proximal contact tightness of direct posterior composite restorations. MATERIALS AND METHODS: 85 patients in need of a two- or three surface Class II direct composite restoration were randomly div

  13. Registration of Hanford Site Class V underground injection wells

    International Nuclear Information System (INIS)

    This document was requested by the Washington State Department of Ecology. Based on the State Underground Injection Control Program, as described in the Washington Administrative Code, French drains and reverse wells are being registered as Class V wells. Information on out-of-service French drains, out-of-service reverse wells, and out-of-service cribs that are deeper than their largest surface dimension is also provided. The data for this submittal were taken from the Waste Information Database System (WIDS) and the Hanford Environmental Compliance Record (HECR) database. The current definition used in WIDS for an ''inactive facility'' is one that either no longer receives waste or plans to in the future. The facilities listed in WIDS as inactive have all been listed as ''out-of-service.'' Information concerning the deactivation method for a facility is included when such information is available. The French drains registered in this submittal are based on the information available at the present time. Additional French drains may be registered on a periodic basis as the drains are identified

  14. 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.

  15. 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. PMID:27652710

  16. Clinical evaluation of the fiber post and direct composite resin restoration for fixed single crowns on endodontically treated teeth

    Science.gov (United States)

    Murali Mohan, S.; Mahesh Gowda, E.; Shashidhar, M.P.

    2015-01-01

    Background The restoration of an endodontically treated fractured tooth has been a challenge for restorative dentists for decades. The performance of fiber posts when used in conjunction with direct composite resin restorations have been largely unreported. This study was conducted with the aim of evaluating the survival rate of endodontically treated teeth restored with adhesive bonded fiber reinforced resin posts and direct composite core with additional crown coverage. Methods Sixty patients who required endodontic treatment with post core crown were selected from outpatient department of Air Force Institute of Dental Sciences, Bangalore. Sixty-four teeth were endodontically treated and restored with fiber post and direct resin composite core restoration. Patients were evaluated immediately after restoration and reevaluated at the end of first, second and third months. After 3 months of clinical evaluation, if teeth were asymptomatic they were restored with complete coverage porcelain fused to metal restorations and evaluated immediately, and again reevaluated at the end of first, third, and sixth months. Results After 3 months of clinical evaluation, only two teeth exhibited periapical lesion with clinical symptoms and three teeth without any clinical symptoms. Five teeth exhibited slight marginal staining, three teeth showed partial loss of restoration, and two teeth exhibited complete loss of restoration with the fracture of the post. At the end of sixth month after restoration with full coverage crown, two teeth had dislodged restoration due to fracture of post and two teeth exhibited displacement of the post. Conclusion Fiber posts are the best alternative for restoration of fractured endodontically treated teeth. Fiber posts and direct composite resin core materials are strongly recommended for restoration of endodontically treated mutilated teeth among the dental establishments of Armed Forces. PMID:26288494

  17. 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....

  18. In vitro evaluation of different liners in microleakage of class II posterior composite restorations

    Directory of Open Access Journals (Sweden)

    Behnaz Esmaeili

    2012-01-01

    Full Text Available Background and Aims: Packable composites with high viscosity might not adapt properly to internal surfaces and cervical areas. The aim of this study was to assess the microleakage of class II posterior composite restorations performed using different methods.Materials and Methods: Ninety proximal cavities were prepared in extracted sound premolar teeth, divided into three groups and filled as follows: 1- packable composite (3M filtek P60, 2-Hybrid composite (Z250 + P60 composite and 3- Resin-modified glass ionomer liner + P60 composite. Afterwards, the samples were immersed in 0.5% Foushin solution and sectioned. Gingival microleakage was then graded. Obtained data were analyzed using paired t-test and analysis of variance. Results: In regard to distal cavities, significant difference was seen between the groups 1 and 3 (P=0.01 as well as groups 2 and 3 (P=0.03. Comparing microleakage of mesial and distal cavities, there was a significant difference in groups 1 (P=0.003 and 2 (P=0.005.Conclusion: Based on the findings of this study, application of Z250 composite had no effect on reduction of microleakage of class II posterior composite restorations. Vitremer liner decreased microleakage in dento-gingival margins.

  19. An update on glass fiber dental restorative composites: a systematic review.

    Science.gov (United States)

    Khan, Abdul Samad; Azam, Maria Tahir; Khan, Maria; Mian, Salman Aziz; Ur Rehman, Ihtesham

    2015-02-01

    Dentistry is a much developed field in the last few decades. New techniques have changed the conventional treatment methods as applications of new dental materials give better outcomes. The current century has suddenly forced on dentistry, a new paradigm regarding expected standards for state-of-the-art patient care. Within the field of restorative dentistry, the incredible advances in dental materials research have led to the current availability of esthetic adhesive restorations. The chemistry and structure of the resins and the nature of the glass fiber reinforced systems in dental composites are reviewed in relation to their influence and properties including mechanical, physical, thermal, biocompatibility, technique sensitivity, mode and rate of failure of restorations on clinical application. It is clear that a deeper understanding of the structure of the polymeric matrix and resin-based dental composite is required. As a result of ongoing research in the area of glass fiber reinforced composites and with the development and advancement of these composites, the future prospects of resin-based composite are encouraging.

  20. Influence of cavity design on the biomechanics of direct composite resin restorations in Class IV preparations.

    Science.gov (United States)

    Xu, Haiping; Jiang, Zhe; Xiao, Ximei; Fu, Jing; Su, Qin

    2012-04-01

    This study evaluated the effect of cavity design on stress distribution and fracture resistance of direct composite resin restorations in Class IV preparations. A finite element analysis (FEA) model of the maxillary central incisor with a Class IV cavity was established. Five model variations were studied: (i) a 1-mm bevel (ii) a 2-mm bevel, (iii) a plain chamfer, (iv) a stair-step chamfer, and (v) butt joints (a control configuration). All FEA variations modeled a tooth restored with composite resin loaded under 100 N at an angle of 45° to the longitudinal axis. The interfacial von Mises stress was evaluated. The FEA was complemented with an in vitro assessment. Fracture resistance of direct composite resin restorations was tested with a universal testing machine and fracture patterns were observed. Finite element analysis showed that stress in chamfer and stair-step chamfer models was more homogenously distributed, while stress in bevel models was relatively concentrated at lingual regions. Fracture resistance of a 1-mm bevel preparation was lower than for the 2-mm bevel, plain chamfer, and stair-step chamfer preparations, but was higher than for butt joints. The stair-step chamfer group presented the most favorable failure pattern. Considering biomechanics and esthetics, the present study indicates that the stair-step chamfer and 2-mm bevel should be recommended for clinical restoration. PMID:22409223

  1. Surface Morphology and Tooth Adhesion of a Novel Nanostructured Dental Restorative Composite

    Directory of Open Access Journals (Sweden)

    Marco Salerno

    2016-03-01

    Full Text Available Recently, a novel dental restorative composite based on nanostructured micro-fillers of anodic porous alumina has been proposed. While its bulk properties are promising thanks to decreased aging and drug delivery capabilities, its surface properties are still unknown. Here we investigated the surface morphology and the adhesion to tooth dentin of this composite as prepared. For comparison, we used two commercial composites: Tetric EVO Flow (Ivoclar and Enamel HRi Plus (Micerium. The surface morphology was characterized by atomic force microscopy and the adhesion strength by tensile tests. The experimental composite is rougher than the commercial composites, with root mean square roughness of ~549 nm against 170–511 nm, and presents an adhesion strength of ~15 MPa against 19–21 MPa. These results show at the same time some proximity to the commercial composites, but also the need for optimization of the experimental material formulation.

  2. Finite element analysis of weakened roots restored with composite resin and posts.

    Science.gov (United States)

    Coelho, Carla Santina de Miranda; Biffi, João Carlos Gabrielli; Silva, Gisele Rodrigues da; Abrahão, Anthony; Campos, Roberto Elias; Soares, Carlos José

    2009-11-01

    Finite element analysis (FEA) was used to investigate the influence of different post systems on the stress distribution of weakened teeth under oblique-load application. A maxillary central incisor root obtained from a sound tooth was weakened by partial removal of dentin inside the root canal. Seven two-dimensional numerical models, one from the sound tooth and six from the weakened root restored with composite resin and post systems were created as follows - ST: sound tooth; CPC: cast CuAl post and core; SSP: stainless steel post + composite core; GP: fiberglass + composite core; CP: carbon fiber + composite core; ZP: zirconium dioxide post + composite core; TP: titanium post + composite core. The numerical models were considered to be restored with a leucite-reinforced all-ceramic crown and received a 45 masculine occlusal load (10 N) on the lingual surface.All the materials and structures were considered linear elastic, homogeneous, and isotropic, with the exception of fiberglass and carbon fiber posts which assumed orthotropic behavior. The numerical models were plotted and meshed with isoparametric elements, and the results were analyzed using von Mises and Sy stress criteria. When compared with the sound tooth, FEA revealed differences in stress distribution when post systems were used. Among the restored teeth, the use of CPC, SSP, ZP, and TP resulted in higher stress concentration in the post itself when compared to GP and CP. Therefore, results from the FEA images suggested that the use of non-metallic post systems could result in improved mechanical behavior for the weakened restored teeth. PMID:20019417

  3. Effect of resealing on microleakage of resin composite restorations in relationship to margin design and composite type

    Science.gov (United States)

    Antonson, Sibel A.; Yazici, A. Ruya; Okte, Zeynep; Villalta, Patricia; Antonson, Donald E.; Hardigan, Patrick C.

    2012-01-01

    Objective: To determine the relationship between margin preparation design and resin-composite type on microleakage with or without re-application of surface-penetrating sealant. Methods: Class-I resin-composite restorations were completed for 128 extracted human molars. Half of the margins were beveled, the other half, butt-joint. Half of each group was restored with Filtek-Supreme (FS), the other half with Esthet-X (EX) using their respective adhesive systems. Margins were etched and sealed with a surface-penetrating sealant, Fortify. The samples were stored in water 24h, and thermocycled (5,000 cycles, 5°C–55°C). Then, samples were abraded using a toothbrush machine (6,000 strokes). Half of the restorations from each sealant group (n=16) were resealed, and the other half had no further treatment. Thermocycling and tooth brushing were repeated. The samples were sealed with nail polish, immersed in methylene-blue for 8h, sectioned, and magnified digital photographs were taken. Three examiners assessed dye penetration. A 2×2×2 multi-layered Chi-Square analysis, using Cochran-Mantel-Haenszel test was conducted for statistical analysis. Results: No difference was observed between sealed and resealed FS and EX restorations with butt-joint margins. In beveled margins, resealing caused significantly less microleakage (Prestorations either sealed or resealed with bevel margins. In butt-joint margins, at the leakage level deeper than 2/3 of the preparation depth, resealed FS showed less microleakage than EX resealed restorations (Pmargins, however, in butt-joint margins resealing did not affect the leakage. A significant statistical relationship exists between and within resealing, margin preparation design, type of composite, and microleakage. PMID:23077418

  4. Effect of pre-treatment with chlorhexidine on the retention of restorations: a randomized controlled trial.

    Science.gov (United States)

    Montagner, Anelise Fernandes; Perroni, Ana Paula; Corrêa, Marcos Britto; Masotti, Alexandre Severo; Pereira-Cenci, Tatiana; Cenci, Maximiliano Sérgio

    2015-01-01

    This study aimed to evaluate the effect of chlorhexidine (CHX) application on etched dentin on the 6-month retention of restorations placed on non-carious cervical lesions (NCCLs). A randomized controlled split-mouth and triple blind trial was carried out. Patients (n=42) with at least two non-carious cervical lesions were included. NCCLs were randomly assigned to two groups: control (placebo solution) or test group (2% CHX solution for 60 s after acid etching and before the adhesive application). Class V restorations (n=169) were performed with an etch-and-rinse adhesive system and composite resin by 10 trained operators. A calibrated examiner evaluated the restorations at 1 week (baseline) and at 6 months using the FDI criteria. The primary outcome was retention of the restorations. The analysis of factors associated to failure of restorations was carried out by Fisher's exact test (α=0.05). After 6 months of follow-up, 3.4% (CI 95% 1.3-7.3) of the restorations failed. There was no statistically significant difference between control and CHX (p=0.920). Regarding the cavity variables, deeper (p=0.04), wider (p=0.004) and wedge-shaped (p=0.033) cavities failed more. Both treatments provided acceptable clinical performance of the restorations. The use of CHX as a adjuvant in dentin adhesion did not influence the retention of Class V restorations after 6 months of follow-up. PMID:26200146

  5. Marginal and internal adaptation of class II restorations after immediate or delayed composite placement.

    Science.gov (United States)

    Dietschi, Didier; Monasevic, Manuela; Krejci, Ivo; Davidson, Carel

    2002-01-01

    Direct class II composite restorations still represent a challenge, particularly when proximal limits extend below the CEJ. The aim of this in vitro study was to evaluate the influence of the type of adhesive and the delay between adhesive placement and composite insertion on restoration adaptation. Direct class II MOD box-shaped composite restorations (n=8 per group) were placed on intact human third molars, with proximal margins 1mm above or under CEJ. All cavities were filled with a horizontal layering technique, immediately after adhesive placement (IP) or after a 24h delay (DP). A filled three-component adhesive (OptiBond FL: OB) and a single-bottle, unfilled one (Prime & Bond 2.1: PB) were tested. Marginal adaptation was assessed before and after each phase of mechanical loading (250000 cycles at 50 N, 250000 cycles at 75 N and 500000 cycles at 100 N); internal adaptation was evaluated after test completion. Gold-plated resin replicas were observed in the SEM and restoration quality evaluated in percentages of continuity (C) at the margins and within the internal interface, after sample section. Adaptation to beveled enamel proved satisfactory in all groups. After loading, adaptation to gingival dentin degraded more in PB-IP (C=55.1%) than PB-DP (C=86.9%) or OB-DP (C=89%). More internal defects were observed in PB samples (IP: C=79.2% and DP: C=86.3%) compared to OB samples (IP: C=97.4% and DP: C=98.3%). The filled adhesive (OB) produced a better adaptation than the 'one-bottle' brand (PB), hypothetically by forming a stress-absorbing layer, limiting the development of adhesive failures. Postponing occlusal loading (such as the indirect approach) improved also restoration adaptation.

  6. Marginal integrity of restorations produced with a model composite based on polyhedral oligomeric silsesquioxane (POSS

    Directory of Open Access Journals (Sweden)

    Luciano Ribeiro CORREA NETTO

    2015-10-01

    Full Text Available Marginal integrity is one of the most crucial aspects involved in the clinical longevity of resin composite restorations.Objective To analyze the marginal integrity of restorations produced with a model composite based on polyhedral oligomeric silsesquioxane (POSS.Material and Methods A base composite (B was produced with an organic matrix with UDMA/TEGDMA and 70 wt.% of barium borosilicate glass particles. To produce the model composite, 25 wt.% of UDMA were replaced by POSS (P25. The composites P90 and TPH3 (TP3 were used as positive and negative controls, respectively. Marginal integrity (%MI was analyzed in bonded class I cavities. The volumetric polymerization shrinkage (%VS and the polymerization shrinkage stress (Pss - MPa were also evaluated.Results The values for %MI were as follows: P90 (100% = TP3 (98.3% = B (96.9% > P25 (93.2%, (p<0.05. The %VS ranged from 1.4% (P90 to 4.9% (P25, while Pss ranged from 2.3 MPa (P90 to 3.9 MPa (B. For both properties, the composite P25 presented the worst results (4.9% and 3.6 MPa. Linear regression analysis showed a strong positive correlation between %VS and Pss (r=0.97, whereas the correlation between Pss and %MI was found to be moderate (r=0.76.Conclusions The addition of 25 wt.% of POSS in methacrylate organic matrix did not improve the marginal integrity of class I restorations. Filtek P90 showed lower polymerization shrinkage and shrinkage stress when compared to the experimental and commercial methacrylate composite.

  7. Effects of temperature change and beverage on mechanical and tribological properties of dental restorative composites.

    Science.gov (United States)

    Ayatollahi, M R; Yahya, Mohd Yazid; Karimzadeh, A; Nikkhooyifar, M; Ayob, Amran

    2015-09-01

    The aim of this study was to investigate the effects of temperature change and immersion in two common beverages on the mechanical and tribological properties for three different types of dental restorative materials. Thermocycling procedure was performed for simulating temperature changes in oral conditions. Black tea and soft drink were considered for beverages. Universal composite, universal nanohybrid composite and universal nanofilled composite, were used as dental materials. The nanoindentation and nanoscratch experiments were utilized to determine the elastic modulus, hardness, plasticity index and wear resistance of the test specimens. The results showed that thermocycling and immersion in each beverage had different effects on the tested dental materials. The mechanical and tribological properties of nanohybrid composite and nanocomposite were less sensitive to temperature change and to immersion in beverages in comparison with those of the conventional dental composite. PMID:26046269

  8. Effects of temperature change and beverage on mechanical and tribological properties of dental restorative composites.

    Science.gov (United States)

    Ayatollahi, M R; Yahya, Mohd Yazid; Karimzadeh, A; Nikkhooyifar, M; Ayob, Amran

    2015-09-01

    The aim of this study was to investigate the effects of temperature change and immersion in two common beverages on the mechanical and tribological properties for three different types of dental restorative materials. Thermocycling procedure was performed for simulating temperature changes in oral conditions. Black tea and soft drink were considered for beverages. Universal composite, universal nanohybrid composite and universal nanofilled composite, were used as dental materials. The nanoindentation and nanoscratch experiments were utilized to determine the elastic modulus, hardness, plasticity index and wear resistance of the test specimens. The results showed that thermocycling and immersion in each beverage had different effects on the tested dental materials. The mechanical and tribological properties of nanohybrid composite and nanocomposite were less sensitive to temperature change and to immersion in beverages in comparison with those of the conventional dental composite.

  9. Marginal and internal fit of nano-composite CAD/CAM restorations

    Science.gov (United States)

    Park, So-Hyun; Shin, Yoo-Jin

    2016-01-01

    Objectives The purpose of this study was to compare the marginal and internal fit of nano-composite CAD-CAM restorations. Materials and Methods A full veneer crown and an mesio-occluso-distal (MOD) inlay cavity, which were prepared on extracted human molars, were used as templates of epoxy resin replicas. The prepared teeth were scanned and CAD-CAM restorations were milled using Lava Ultimate (LU) and experimental nano-composite CAD/CAM blocks (EB) under the same milling parameters. To assess the marginal and internal fit, the restorations were cemented to replicas and were embedded in an acrylic mold for sectioning at 0.5 mm intervals. The measured gap data were pooled according to the block types and measuring points for statistical analysis. Results Both the block type and measuring point significantly affected gap values, and their interaction was significant (p = 0.000). In crowns and inlays made from the two blocks, gap values were significantly larger in the occlusal area than in the axial area, while gap values in the marginal area were smallest (p inlays had significantly larger gaps than LU restorations. PMID:26877989

  10. Comparison of shear bond strength of orthodontics brackets on composite resin restorations with different surface treatments

    Directory of Open Access Journals (Sweden)

    Alexandre Antonio Ribeiro

    2013-08-01

    Full Text Available INTRODUCTION: Orthodontic patients frequently present composite resin restorations, however there are few studies that evaluate the best way for orthodontic bonding in this situation. OBJECTIVE: The objective of this work was to evaluate the bond strength of orthodontic brackets in resin restorations with surface treatment. METHODS: Fifty one bovine lower incisors were randomly divided into three groups. On the control group (CG the brackets were bonded to dental enamel; on experimental groups, brackets were bonded to resin restoration with diamond drill treatment (EGT and with no treatment (EGN. The teeth were placed in PVC tubes with autopolymerized acrylic resin. The shear test was performed in EMIC universal testing machine. The groups were submitted to ANOVA analysis of variance with Tukey post test to verify the statistical difference between groups (α = 0.05. RESULTS: CG (6.62 MPa and EGT (6.82 MPa groups presented similar results, while EGN (5.07 MPa obtained statistically lower results (p < 0.05. CONCLUSION: Therefore, it is concluded that the best technique for bonding of orthodontic brackets on composite resin restorations is the performance of surface detritions.

  11. Marginal and internal adaptation of Class II ormocer and hybrid resin composite restorations before and after load cycling.

    Science.gov (United States)

    Kournetas, N; Chakmakchi, M; Kakaboura, A; Rahiotis, C; Geis-Gerstorfer, J

    2004-09-01

    To overcome the shortcomings of the conventional composite restorative materials, ormocer materials have been introduced over the past few years. The purpose of this study was to evaluate the marginal and internal adaptation of two ormocer restorative systems (Admira, Voco and Definite, Degussa) compared to a hybrid composite one (TPH Spectrum, Dentsply/ DeTrey), before and after load cycling in Class II restorations. Standardized Class II restorations with cervical margins on enamel were divided into three groups ( n=16). Teeth of each group were filled with one of the restoratives tested and its respective bonding agent. Each group was divided into two equal subgroups. The marginal and internal adaptation of the first subgroup was evaluated after 7-day water storage at room temperature and of the second after cyclic loading in a mastication simulator (1.2x10(6) cycles, 49 N, 1.6 Hz). The occlusal and cervical marginal evaluation was conducted by videomicroscope and ranked as "excellent" and "not excellent". One thin section (150 microm), in mesial-distal direction, of each restoration, was examined under metallographic microscope to determine the quality of internal adaptation. The occlusal and cervical adaptation of both ormocer restorative systems was similar and clearly worse compared with the hybrid composite restorative one before as well as after load cycling. Concerning internal adaptation, no gap-free ormocer restorations were detected, whereas all Spectrum restorations presented perfect adaptation. The bonding agents of the ormocers formed layers with unacceptable features (pores, fractures) whereas that of the hybrid composite achieved perfect bonding layer even after loading. The rheological characteristics of the bonding agents of the ormocer restorative systems are proposed to be responsible for their inferior marginal and internal quality in Class II restorations compared with the hybrid composite one.

  12. Multispectral near-infrared imaging of composite restorations in extracted teeth

    Science.gov (United States)

    Logan, Cooper M.; Co, Katrina U.; Fried, William A.; Simon, Jacob C.; Staninec, Michal; Fried, Daniel; Darling, Cynthia L.

    2014-02-01

    One major advantage of composite restoration materials is that they can be color matched to the tooth. However, this presents a challenge when composites fail and they need to be replaced. Dentists typically spend more time repairing and replacing composites than placing new restorations. Previous studies have shown that near-infrared imaging can be used to distinguish between sound enamel and decay due to the differences in light scattering. The purpose of this study was to use a similar approach and exploit differences in light scattering to attain high contrast between composite and tooth structure. Extracted human teeth with composites (n=16) were imaged in occlusal transmission mode at wavelengths of 1300-nm, 1460-nm and 1550-nm using an InGaAs image sensor with a tungsten halogen light source with spectral filters. All samples were also imaged in the visible range using a high definition 3D digital microscope. Our results indicate that NIR wavelengths at 1460-nm and 1550-nm, coincident with higher water absorption yield the highest contrast between dental composites and tooth structure.

  13. Multispectral Near-Infrared Imaging of Composite Restorations in Extracted Teeth.

    Science.gov (United States)

    Logan, Cooper M; Co, Katrina U; Fried, William A; Simon, Jacob C; Staninec, Michal; And, Daniel Fried; Darling, Cynthia L

    2014-02-20

    One major advantage of composite restoration materials is that they can be color matched to the tooth. However, this presents a challenge when composites fail and they need to be replaced. Dentists typically spend more time repairing and replacing composites than placing new restorations. Previous studies have shown that near-infrared imaging can be used to distinguish between sound enamel and decay due to the differences in light scattering. The purpose of this study was to use a similar approach and exploit differences in light scattering to attain high contrast between composite and tooth structure. Extracted human teeth with composites (n=16) were imaged in occlusal transmission mode at wavelengths of 1300-nm, 1460-nm and 1550-nm using an InGaAs image sensor with a tungsten halogen light source with spectral filters. All samples were also imaged in the visible range using a high definition 3D digital microscope. Our results indicate that NIR wavelengths at 1460-nm and 1550-nm, coincident with higher water absorption yield the highest contrast between dental composites and tooth structure. PMID:25309098

  14. A Conservative Esthetic Approach Using Enamel Recontouring and Composite Resin Restorations

    Science.gov (United States)

    Andrade, Aline Silva

    2016-01-01

    Conservative clinical solutions, predictable esthetic, and immediate outcomes are important concepts of restorative dentistry. The aim of this case study was to recognize the selective enamel removal as an interesting conservative alternative to achieve optimal esthetic results and discuss the clinical protocol. This clinical report described an alternative esthetic and conservative treatment to transform the long and sharp aspect of the maxillary canines with a slightly aggressive aspect into features of slightly curved teeth with delicate lines. An accurate diagnostic and esthetic analysis of the smile was initially performed. The selective enamel removal was performed, and direct composite restoration was strategically placed. Clinical assessment showed good esthetic outcomes, enabling a smile harmony with an immediate, simple, and lower-cost technique. Practitioners should be exposed to conservative approaches to create esthetic smiles based on the selective enamel removal technique combined with composite resin. PMID:27812389

  15. A study of composite restorations as a tool in forensic identification

    OpenAIRE

    Bahavathi Ananthan Hemasathya; Sundaresan Balagopal

    2013-01-01

    Introduction: Comparing ante-mortem and post-mortem dental data is a principal method of identification in forensic odontology. Radiographic images of amalgam have been used in dental forensics for identification due to their unique appearance. Aim: The aim of this study was to investigate whether radio-opaque composite restorations have a potential for identification in forensic odontology. Materials and Methods: Thirty typodont mandibular first molar teeth were prepared with Class-II (proxi...

  16. Marginal Integrity of Bulk Versus Incremental Fill Class II Composite Restorations.

    Science.gov (United States)

    Al-Harbi, F; Kaisarly, D; Bader, D; El Gezawi, M

    2016-01-01

    Bulk-fill composites have been introduced to facilitate the placement of deep direct resin composite restorations. This study aimed at analyzing the cervical marginal integrity of bulk-fill vs incremental and open-sandwich class II resin composite restorations after thermomechanical cycling using replica scanning electron microscopy (SEM) and ranking according to the World Dental Federation (FDI) criteria. Box-only class II cavities were prepared in 91 maxillary premolars with the gingival margin placed 1 mm above and below the cemento-enamel junction. Eighty-four premolars were divided into self-etch and total-etch groups, then subdivided into six restorative subgroups (n=7): 1-Tetric Ceram HB (TC) was used incrementally and in the open-sandwich technique with 2-Tetric EvoFlow (EF) and 3-Smart Dentin Replacement (SD). Bulk-fill restoratives were 4-SonicFill (SF), 5-Tetric N-Ceram Bulk Fill (TN), and 6-Tetric EvoCeram Bulk Fill (TE). In subgroups 1-5, Tetric N-Bond self-etch and Tetric N-Bond total-etch adhesives were used, whereas in subgroup 6, AdheSE self-etch and ExciTE F total etch were used. One more group (n=7) was restored with Filtek P90 Low Shrink Posterior Restorative (P9) only in combination with its self-etch P90 System Adhesive. Materials were manipulated and light cured (20 seconds, 1600 mW/cm(2)), and restorations were artificially aged by thermo-occlusal load cycling. Polyvinyl-siloxane impressions were taken and poured with epoxy resin. Resin replicas were examined by SEM (200×) for marginal sealing, and percentages of perfect margins were analyzed. Moreover, samples were examined using loupes (3.5×) and explorers and categorized according to the FDI criteria. Results were statistically analyzed (SEM by Kruskal-Wallis test and FDI by chi-square test) without significant differences in either the replica SEM groups (p=0.848) or the FDI criteria groups (p>0.05). The best SEM results at the enamel margin were in TC+EF/total-etch and SF

  17. Physical properties and microstructure of ceramic–polymer composites for restoration works

    International Nuclear Information System (INIS)

    Highlights: ► Density, porosity and modulus decreased, whereas strength increased with polymer addition larger steatite particles. ► An interaction effect was found for the porosity. ► The material colour was similar to soapstone being useful for restoration works. - Abstract: Cement mortars prepared with steatite particles have been investigated for restoration of sculptures and other craftworks. This work investigates the addition of a thermoset polymer into cement-based composites reinforced with residues of steatite particles in order to seal the open pores, reduce water penetration and thus enhancing the material's lifetime. A full factorial design of 2141 type was carried out to investigate the effect of the steatite particle size and polymeric fraction on the physical and mechanical properties of the composite materials, such as bulk density, apparent porosity, elastic modulus and compressive strength. Scanning electron microscopy (SEM) was used to reveal features in the microstructure that are related to the physical properties. Results have shown that highest compressive strength (43 MPa) and lowest apparent porosity (0.19%) are achieved when steatite particles are coarser (ranging from 1.41 mm to 0.42 mm) and 40% of polymeric phase is employed. The composite with best performance also presented texture and colour quite similar to the surface characteristics of the natural soap-stone, which makes it suitable for restoration purposes.

  18. 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.

  19. Clinical longevity of extensive direct composite restorations in amalgam replacement : Up to 3.5 years follow-up

    NARCIS (Netherlands)

    Scholtanus, Johannes D.; Ozcan, Mutlu

    2014-01-01

    Objectives: This prospective clinical trial evaluated the longevity of direct resin composite (DRC) restorations made on stained dentin that is exposed upon removal of existing amalgam restorations in extensive cavities with severely reduced macro-mechanical retention for amalgam replacement. Method

  20. Resin composite restoration in primary anterior teeth using short-post technique and strip crowns: a case report.

    Science.gov (United States)

    Mendes, Fausto Medeiros; De Benedetto, Monique Saveriano; del Conte Zardetto, Cristina Giovannetti; Wanderley, Marcia Turolla; Correa, Maria Salete Nahás Pires

    2004-10-01

    A case report describing a technique for the restoration of endodontically treated primary maxillary incisors with resin composite short posts and celluloid strip crowns in a 3-year-old boy is presented. The technique offers the advantages of using one restorative material, improving esthetics, and reducing chairtime and costs. PMID:15470991

  1. Contraction behaviors of dental composite restorations--finite element investigation with DIC validation.

    Science.gov (United States)

    Chuang, Shu-Fen; Chang, Chih-Han; Chen, Terry Yuan-Fang

    2011-11-01

    The objective of this study was to examine the effects of cavity configuration on the polymerization shrinkage and stress of light-cured composite restorations by combining local strain measurement and a finite element analysis (FEA). Dental mesio-occluso-distal cavities of various widths and depths (each for 2 vs. 4 mm), representing different configuration factors, were prepared on extracted molars. The displacements of the bonded tooth cusps and cavity floors, caused by polymerization shrinkage of composite restorations, were assessed utilizing a digital-image-correlation (DIC) technique. The cervical marginal microleakage was investigated by examining the resin replicas of these restorations under SEM. The local material properties of the polymerized composite along the curing depth were defined by the nanoindentation test and applied in the subsequent FEA. In the FEA, four models were generated to correspond with the experimental restorations. In the DIC measurement results, the 4(w)×4(D) mm cavity presented the greatest values of inward displacements at the cusp and floor. The cavity depth, rather than the cavity width, was found to significantly correlate to the floor deformation, the location of shrinkage centers, and also the cervical microleakage ratio. The FEA simulation results showed that the 2(w)×4(D) mm cavity presented the maximal von Mises and principal stress located respectively on the cervical margins and cavity floor. Additional safety factor analysis showed a high risk of bond failure over the cavity floor in the 4-mm deep cavity. With the experimental validation, the simulation revealed that the cavity depth was significant to the formation of contraction stress and the incidence of interfacial debonding. PMID:22098914

  2. Contraction behaviors of dental composite restorations--finite element investigation with DIC validation.

    Science.gov (United States)

    Chuang, Shu-Fen; Chang, Chih-Han; Chen, Terry Yuan-Fang

    2011-11-01

    The objective of this study was to examine the effects of cavity configuration on the polymerization shrinkage and stress of light-cured composite restorations by combining local strain measurement and a finite element analysis (FEA). Dental mesio-occluso-distal cavities of various widths and depths (each for 2 vs. 4 mm), representing different configuration factors, were prepared on extracted molars. The displacements of the bonded tooth cusps and cavity floors, caused by polymerization shrinkage of composite restorations, were assessed utilizing a digital-image-correlation (DIC) technique. The cervical marginal microleakage was investigated by examining the resin replicas of these restorations under SEM. The local material properties of the polymerized composite along the curing depth were defined by the nanoindentation test and applied in the subsequent FEA. In the FEA, four models were generated to correspond with the experimental restorations. In the DIC measurement results, the 4(w)×4(D) mm cavity presented the greatest values of inward displacements at the cusp and floor. The cavity depth, rather than the cavity width, was found to significantly correlate to the floor deformation, the location of shrinkage centers, and also the cervical microleakage ratio. The FEA simulation results showed that the 2(w)×4(D) mm cavity presented the maximal von Mises and principal stress located respectively on the cervical margins and cavity floor. Additional safety factor analysis showed a high risk of bond failure over the cavity floor in the 4-mm deep cavity. With the experimental validation, the simulation revealed that the cavity depth was significant to the formation of contraction stress and the incidence of interfacial debonding.

  3. The effect of a fiber reinforced cavity configuration on load bearing capacity and failure mode of endodontically treated molars restored with CAD/CAM resin composite overlay restorations

    NARCIS (Netherlands)

    G.T. Rocca; C.M. Saratti; M. Cattani-Lorente; A.J. Feilzer; S. Scherrer; I. Krecji

    2015-01-01

    Objectives To evaluate the fracture strength and the mode of failure of endodontically treated molars restored with CAD/CAM overlays with fiber reinforced composite build-up of the pulp chamber. Methods 40 Devitalized molars were cut over the CEJ and divided into five groups (n = 8). The pulp chambe

  4. Fracture Resistance of Premolars Restored by Various Types and Placement Techniques of Resin Composites

    Directory of Open Access Journals (Sweden)

    Horieh Moosavi

    2012-01-01

    Full Text Available To verify the fracture resistance of premolars with mesioocclusodistal preparations restored by different resin composites and placement techniques. Sixty premolars were randomly divided into two groups based on type of composite resin: Filtek P60 or Nulite F, and then each group was separated into three subgroups: bulk, centripetal, and fiber insert according to the type of placement method (n=10. Single-bond adhesive system was used as composite bonding according to the manufacturer's instructions. Specimens were restored in Groups 1, 2, and 3 with Filtek P60 and in Groups 4, 5, and 6 with Nulite F. After being stored 24 hours at 37∘C, a 4 mm diameter steel sphere in a universal testing machine was applied on tooth buccal and lingual cusps at a cross-head speed of 5 mm/min until fracture occurred. Groups 3 and 6 showed higher fracture resistance than Groups 1, 2, 4, and 5. Among the placement techniques, the fiber insert method had a significant effect, but the type of composite was ineffective. The insertion technique in contrast to the type of material had a significant influence on the fracture resistance of premolar teeth.

  5. Swept source optical coherence tomography for quantitative and qualitative assessment of dental composite restorations

    Science.gov (United States)

    Sadr, Alireza; Shimada, Yasushi; Mayoral, Juan Ricardo; Hariri, Ilnaz; Bakhsh, Turki A.; Sumi, Yasunori; Tagami, Junji

    2011-03-01

    The aim of this work was to explore the utility of swept-source optical coherence tomography (SS-OCT) for quantitative evaluation of dental composite restorations. The system (Santec, Japan) with a center wavelength of around 1300 nm and axial resolution of 12 μm was used to record data during and after placement of light-cured composites. The Fresnel phenomenon at the interfacial defects resulted in brighter areas indicating gaps as small as a few micrometers. The gap extension at the interface was quantified and compared to the observation by confocal laser scanning microscope after trimming the specimen to the same cross-section. Also, video imaging of the composite during polymerization could provide information about real-time kinetics of contraction stress and resulting gaps, distinguishing them from those gaps resulting from poor adaptation of composite to the cavity prior to polymerization. Some samples were also subjected to a high resolution microfocus X-ray computed tomography (μCT) assessment; it was found that differentiation of smaller gaps from the radiolucent bonding layer was difficult with 3D μCT. Finally, a clinical imaging example using a newly developed dental SS-OCT system with an intra-oral scanning probe (Panasonic Healthcare, Japan) is presented. SS-OCT is a unique tool for clinical assessment and laboratory research on resin-based dental restorations. Supported by GCOE at TMDU and NCGG.

  6. Adaptation of two different calcium hydroxide bases under a composite restoration.

    Science.gov (United States)

    Papadakou, M; Barnes, I E; Wassell, R W; McCabe, J F

    1990-10-01

    A preliminary scanning electron microscope (SEM) study was carried out to investigate how the adaptation of two calcium hydroxide bases (one chemically cured, one light cured) was affected by the polymerization contraction of a supervening light-cured composite resin restoration. Occlusal cavities were prepared in 40 sound extracted human premolars, divided into two equal groups. In the first group a chemically cured calcium hydroxide (Dycal, De Trey Dentsply, Konstanz, FRG) was placed as a base. In the second group a new light-cured calcium hydroxide product (Prisma VLC Dycal, De Trey Dentsply) was used. The restorations were completed with an acid-etched, incrementally placed composite resin. The specimens were sectioned vertically and debrided. A replica was made of each half-tooth. The interfaces between composite resin/base and base/dentine were viewed and photographed in the SEM. The marginal adaptation at these two interfaces was classified into three categories according to the extent of the gaps that were observed. Prisma VLC Dycal base was found to be pulled away from the dentine floor of the cavity as a result of an apparent adhesion to the composite resin during polymerization contraction. Dycal was better adapted to the cavity floor than Prisma VLC Dycal. Disorganization of the resin-bonded Prisma VLC Dycal was minimal even after acid etching the enamel, sectioning and ultrasonic debridement. Dycal appeared to be more friable, and occasionally exhibited marked disorganization as a result of these procedures.

  7. 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.

  8. Finite Element Analysis of the Effect of Proximal Contour of Class II Composite Restorations on Stress Distribution

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Moghaddas

    2013-01-01

    Full Text Available Introduction: The aim of this study was to evaluate the effect of proximal contour of class II composite restorations placed with straight or contoured matrix band using composite resins with different modulus of elasticity on stress distribution by finite element method. Methods: In order to evaluate the stress distribution of class II composite restorations using finite element method, upper right first molar and second premolar were modeled. Proximal boxes were designed and restored with universal Z250 and packable P60 composite resins (3M ESPE using two matrix systems: flat Tofflemire matrix and precurved sectional matrix. Finally models were evaluated under loads of 200 and 400 Newton at 90 degrees angle and the results were graphically illustrated in the form of Von Misses stresses. Results: In general the stress obtained under 400 Newton load was significantly greater than the stress of models under 200 Newton load. Von Misses stress distribution pattern of two different Z250 and P60 composites were very similar in all modes of loading and proximal contour. In all analyzed models there was a significant difference between models restored with Tofflemire matrix with flat contour and models restored with sectional matrix with curved contour. This difference was greater in first molar than second premolar. Conclusion: Use of a contoured matrix band results in less stress in class II composite resin restorations.

  9. Finite Element Analysis of the Effect of Proximal Contour of Class II Composite Restorations on Stress Distribution

    Directory of Open Access Journals (Sweden)

    Hossein Abachizadeh

    2012-09-01

    Full Text Available Introduction: The aim of this study was to evaluate the effect of proximal contour of class II composite restorations placed with straight or contoured matrix band using composite resins with different modulus of elasticity on stress distribution by finite element method. Methods: In order to evaluate the stress distribution of class II composite restorations using finite element method, upper right first molar and second premolar were modeled. Proximal boxes were designed and restored with universal Z250 and packable P60 composite resins (3M ESPE using two matrix systems: flat Tofflemire matrix and precurved sectional matrix. Finally models were evaluated under loads of 200 and 400 Newton at 90 degrees angle and the results were graphically illustrated in the form of Von Misses stresses. Results: In general the stress obtained under 400 Newton load was significantly greater than the stress of models under 200 Newton load. Von Misses stress distribution pattern of two different Z250 and P60 composites were very similar in all modes of loading and proximal contour. In all analyzed models there was a significant difference between models restored with Tofflemire matrix with flat contour and models restored with sectional matrix with curved contour. This difference was greater in first molar than second premolar. Conclusion: Use of a contoured matrix band results in less stress in class II composite resin restorations.

  10. 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.

  11. 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

  12. The Post-Amalgam Era: Norwegian Dentists’ Experiences with Composite Resins and Repair of Defective Amalgam Restorations

    Science.gov (United States)

    Kopperud, Simen E.; Staxrud, Frode; Espelid, Ivar; Tveit, Anne Bjørg

    2016-01-01

    Amalgam was banned as a dental restorative material in Norway in 2008 due to environmental considerations. An electronic questionnaire was sent to all dentists in the member register of the Norwegian Dental Association (NTF) one year later, to evaluate dentists’ satisfaction with alternative restorative materials and to explore dentists’ treatment choices of fractured amalgam restorations. Replies were obtained from 61.3%. Composite was the preferred restorative material among 99.1% of the dentists. Secondary caries was the most commonly reported cause of failure (72.7%), followed by restoration fractures (25.1%). Longevity of Class II restorations was estimated to be ≥10 years by 45.8% of the dentists, but 71.2% expected even better longevity if the restoration was made with amalgam. Repair using composite was suggested by 24.9% of the dentists in an amalgam restoration with a fractured cusp. Repair was more often proposed among young dentists (p Dental Service (PDS) (p amalgam restorations. PMID:27110804

  13. The Post-Amalgam Era: Norwegian Dentists' Experiences with Composite Resins and Repair of Defective Amalgam Restorations.

    Science.gov (United States)

    Kopperud, Simen E; Staxrud, Frode; Espelid, Ivar; Tveit, Anne Bjørg

    2016-01-01

    Amalgam was banned as a dental restorative material in Norway in 2008 due to environmental considerations. An electronic questionnaire was sent to all dentists in the member register of the Norwegian Dental Association (NTF) one year later, to evaluate dentists' satisfaction with alternative restorative materials and to explore dentists' treatment choices of fractured amalgam restorations. Replies were obtained from 61.3%. Composite was the preferred restorative material among 99.1% of the dentists. Secondary caries was the most commonly reported cause of failure (72.7%), followed by restoration fractures (25.1%). Longevity of Class II restorations was estimated to be ≥10 years by 45.8% of the dentists, but 71.2% expected even better longevity if the restoration was made with amalgam. Repair using composite was suggested by 24.9% of the dentists in an amalgam restoration with a fractured cusp. Repair was more often proposed among young dentists (p Dental Service (PDS) (p amalgam restorations. PMID:27110804

  14. Acceleration and novelty: community restoration speeds recovery and transforms species composition in Andean cloud forest.

    Science.gov (United States)

    Wilson, Sarah Jane; Rhemtulla, Jeanine M

    2016-01-01

    Community-based tropical forest restoration projects, often promoted as a win-win solution for local communities and the environment, have increased dramatically in number in the past decade. Many such projects are underway in Andean cloud forests, which, given their extremely high biodiversity and history of extensive clearing, are understudied. This study investigates the efficacy of community-based tree-planting projects to accelerate cloud forest recovery, as compared to unassisted natural regeneration. This study takes place in northwest Andean Ecuador, where the majority of the original, highly diverse cloud forests have been cleared, in five communities that initiated tree-planting projects to restore forests in 2003. In 2011, we identified tree species along transects in planted forests (n = 5), naturally regenerating forests (n = 5), and primary forests (n = 5). We also surveyed 120 households about their restoration methods, tree preferences, and forest uses. We found that tree diversity was higher in planted than in unplanted secondary forest, but both were less diverse than primary forests. Ordination analysis showed that all three forests had distinct species compositions, although planted forests shared more species with primary forests than did unplanted forests. Planted forests also contained more animal-dispersed species in both the planted canopy and in the unplanted, regenerating understory than unplanted forests, and contained the highest proportion of species with use value for local people. While restoring forest increased biodiversity and accelerated forest recovery, restored forests may also represent novel ecosystems that are distinct from the region's previous ecosystems and, given their usefulness to people, are likely to be more common in the future. PMID:27039520

  15. Acceleration and novelty: community restoration speeds recovery and transforms species composition in Andean cloud forest.

    Science.gov (United States)

    Wilson, Sarah Jane; Rhemtulla, Jeanine M

    2016-01-01

    Community-based tropical forest restoration projects, often promoted as a win-win solution for local communities and the environment, have increased dramatically in number in the past decade. Many such projects are underway in Andean cloud forests, which, given their extremely high biodiversity and history of extensive clearing, are understudied. This study investigates the efficacy of community-based tree-planting projects to accelerate cloud forest recovery, as compared to unassisted natural regeneration. This study takes place in northwest Andean Ecuador, where the majority of the original, highly diverse cloud forests have been cleared, in five communities that initiated tree-planting projects to restore forests in 2003. In 2011, we identified tree species along transects in planted forests (n = 5), naturally regenerating forests (n = 5), and primary forests (n = 5). We also surveyed 120 households about their restoration methods, tree preferences, and forest uses. We found that tree diversity was higher in planted than in unplanted secondary forest, but both were less diverse than primary forests. Ordination analysis showed that all three forests had distinct species compositions, although planted forests shared more species with primary forests than did unplanted forests. Planted forests also contained more animal-dispersed species in both the planted canopy and in the unplanted, regenerating understory than unplanted forests, and contained the highest proportion of species with use value for local people. While restoring forest increased biodiversity and accelerated forest recovery, restored forests may also represent novel ecosystems that are distinct from the region's previous ecosystems and, given their usefulness to people, are likely to be more common in the future.

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

    International Nuclear Information System (INIS)

    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)

  17. Effects of composite restorations on nitric oxide and uric acid levels in saliva

    Directory of Open Access Journals (Sweden)

    Nilgun Akgul

    2015-01-01

    Full Text Available Background and Aims: Dental materials that are used in dentistry should be harmless to oral tissues, and should, therefore, not contain any leachable toxic and diffusible substances capable of causing side effects. This study was intended to investigate the effects on salivary nitric oxide (NO and uric acid (UA levels after application of dental composite filling materials to healthy volunteers. Materials and Methods: A total of 52 individuals (32 female and 20 male participated in the study. Filtek Z250 composite filling material (3M ESPE, St Paul, MN, USA was applied to healthy volunteers. Saliva samples were collected before restoration (baseline and 1 h, 1-day, 7 days, and 30 days after restoration. NO concentrations were measured using the Griess reaction method, and UA was measured using an enzymatic method. Data were analyzed using repeated measures ANOVA and the Bonferroni post-hoc test (α =5%. Results: NO values increased statistically significant after 7 days (P 0.05. There was no correlation between NO and UA levels in saliva (P > 0.05. Conclusion: Composite resins activated the antioxidant system in saliva. However, further studies are now needed to confirm our findings and to permit a definitive conclusion.

  18. 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)

  19. Marginal adaptation of class II resin composite restorations using incremental and bulk placement techniques: an ESEM study.

    Science.gov (United States)

    Idriss, S; Habib, C; Abduljabbar, T; Omar, R

    2003-10-01

    This in vitro study compared marginal gap formation in class II resin composite restorations. Forty caries-free extracted molars were prepared in a standardized manner for class II restoration by one of four methods: bulk- or incrementally-placed light-activated resin composite (Amelogen), and bulk- or incrementally-placed chemically activated composite (Rapidfill). The restored teeth, after finishing and polishing, and thermocycling, were examined using environmental scanning electron microscopy. Marginal gap measurements at predetermined facial and lingual margin sites showed no significant differences between the two sites within any of the groups. Both the light- and the chemically-activated restorations showed no significant differences in mean marginal gap sizes whether they were placed by incremental or bulk techniques. Amelogen restorations placed by both methods had significantly larger margin gaps than those of each of the Rapidfill groups (Peffect on the quality of marginal adaptation, both of the chemically activated resin composite restorations produced significantly smaller marginal gaps than both the bulk- and incrementally-placed light-activated composites. PMID:12974860

  20. Analysis of Fracture Signals from Tooth/Composite Restoration According to AE Sensor Attachment

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Ja Uk; Choi, Nak Sam [Hanyang University, Ansan (Korea, Republic of)

    2011-10-15

    Acoustic emission(AE) signals during the polymerization shrinkage of composite resin subjected to the LED light exposure were detected through a wave guide method and a direct sensor attachment method. For PMMA, human tooth, stainless steel substrate, data of AE hits and amplitudes were compared. For the test using the wave guide, AE amplitudes decreased because of the attenuant wave. However, AE hits and 1st peak frequency distribution were not different according to the sensor attachments. Through the experiments, wave guide could be used for a nondestructive evaluation of the marginal disintegrative fracture of dental restoration.

  1. Effect on Micro-Leakage of Composite Resoration with Two Different Adhesives after Bleaching

    OpenAIRE

    Nazish Fatima; Sidr Mohiuddin; Wasif Iqbal

    2015-01-01

    OBJECTIVE: To evaluate the effects of two different adhesive systems after bleaching with 38% Hydrogen peroxide onmicroleakage of Class V composite resin restorations. MATERIALS & METHODS: The materials used in this study included Nano composite (Filtek Z350), Scotchbond™ Dual Cure Dental Adhesive (3M™ ESPE™), Prime and bond elect (Dentsply) and Power whitening gel (White Smile 2011, Germany). Sixty sound human premolars were stored in thymol solution (Buffered 0.1% pH 7.00) for about one ...

  2. Nanoleakage Evaluation of Posterior Teeth Restored with Low Shrinkable Resin Composite- An invitro Study

    Science.gov (United States)

    Labib, Labib Mohamed; Nabih, Sameh Mahmoud

    2016-01-01

    Introduction The effect of nanoleakage on the integrity of resin–dentin bond has been in interest for long-term adhesion. Aim This study evaluated the nanoleakage in premolar teeth restored with low shrinkable resin composite. Materials and Methods A total of 40 human premolars were used for nanoleakage evaluation in this study. Each group was divided into four equal groups; Group A: using silorane with its adhesive system. Group B: using silorane with G-bond. Group C: using Filtek supreme composite with G-bond. Group D: using Filtek supreme composite with AdheSE adhesive. Nanoleakage analysed using Scaning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectrometery (EDX). Results The amount of silver present in hybrid layer depend on the adhesive used; this indicated different nanoleakage expressions in different adhesive systems. Filtek Z350 composite with G-bond showed clear silver uptake in both the adhesive and hybrid layer. Low shrinkable resin composite (silorane) with its adhesive system showed less silver penetration and slight silver peak on the elemental energy spectroscopy of energy dispersive X-Ray spectrometry (EDS) as compared to other samples. Conclusion Adhesives used between different groups, influence the location and degree of nanoleakage. There is difference in nanoleakage patterns between two-step and one-step adhesives and also among the one-step adhesives themselves. PMID:27630943

  3. Fracture Strength of Indirect Resin Composite Laminates to Teeth with Existing Restorations : An Evaluation of Conditioning Protocols

    NARCIS (Netherlands)

    Mese, Ayse; Ozcan, Mutlu

    2009-01-01

    Purpose: This study evaluated the fracture strength and failure types of indirect resin-based composite laminates bonded to teeth with aged Class III composite restorations that were conditioned according to various protocols. Materials and Methods: Maxillary central incisors (N = 60) with window-ty

  4. STUDY OF THE EFFECT OF DIRECT & INDIRECT COMPOSITE RESTORATIONS ON RESISTANCE TO MAXILLARY PREMOLLAR TEATH FRACTURE TREATED BY ROOT CANAL METHOD

    OpenAIRE

    M Mousavinasab; S. Ashrafijoo

    2003-01-01

    Finding a universally approved system to restore pulpess teeth has been a goal of many of dental researches. The restorative system should have enough ability to withstand masticator forces, while preserving as much tooth structure as possible. The purpose of this study was to compare the effects of light and heat curing composite with light curing composite restoration method on fracture resistance of restored teeth. Forty healthy maxillary premolar teeth were chosen, in thirty of sampl...

  5. The effect of Er, Cr:YSGG laser irradiation on the microleakage of composite resin restorations%Er,Cr:YSGG激光制洞对光固化复合树脂边缘微渗漏的影响

    Institute of Scientific and Technical Information of China (English)

    贾兴亚; 王凤艳; 刘策

    2011-01-01

    目的:比较在自酸蚀黏结剂的应用条件下,Er,Cr:YSGG激光制备与传统牙钻制备离体牙牙颈部洞对光固化复合树脂边缘微渗漏的影响.方法:将20个因正畸拔除的新鲜完整无龋损、无隐裂、无充填物的前磨牙随机分为两组(n=10),分别使用牙钻和Er,Cr:YSGG激光制备牙颈部洞.窝洞制备后均匀涂覆FL-BOND,用TPH复合树脂进行分层充填,打磨、抛光,37℃生理盐水中存放7d后,进行500次温度循环实验(5±2)℃—(55±2)℃.将上述所有样本置0.5%碱性品红液中室温浸泡24h后,沿牙体长轴通过修复体正中纵行剖开,采用染料渗入法和扫描电镜方法观察充填体微渗漏情况,运用SPSS 11.0软件包进行统计学处理.结果:牙钻制备组与激光组相比,无论(牙合)壁还是龈壁的染料渗入评分和边缘微缝隙宽度均无显著性差异(P>0.05).结论:在自酸蚀黏结剂的应用条件下,Er,Cr:YSGG激光制洞不能显著减少光固化复合树脂边缘微渗漏的发生.%AIM: To compare the microleakage of Class V resin composite restorations following Er,Cr:YS-GG laser and high -speed rotary preparation using a self-etch adhesive system. METHODS; Twenty orthodontically extracted human premolars were randomly divided into two groups (n = 10) and Class V cavities were prepared in the teeth with Er,Cr:YSGG laser or bur. The cavities were then coated with FL-BOND adhesive system and TPH resin composite was used for restoration. After finishing and polishing, the teeth were stored for seven days in distilled water at 37 t before they were subjected to thermocycling for 500 times (5 ±2℃ -55 ±2℃ ). Then they were stained in asolution of 0.5% basic fuchsion at room temperature and sectioned in a buccolingual plane through the centre of the restorations. The marginal microleakage was observed by dye penetration method and SEM. The data was analyzed with SPSS11.0 software package. RESULTS: Microleakage test and the space

  6. Mechanistic aspects of fracture and fatigue in resin based dental restorative composites

    Science.gov (United States)

    Shah, Minalben B.

    For resin based dental restorative composites, one of the major challenges is to optimize the balance between mechanical and optical properties. Although fracture is the second leading cause of dental restorative failures, very limited mechanistic understanding exists on a microscopic level. In the present study, the fracture properties and mechanisms of two commercial dental resin composites with different microstructures are examined using double notched four point beam bending and pre-cracked compact-tension, C(T), specimens. Four point bend flexural strength was also measured using un-notched beam samples. The first material is a microhybrid composite that combines a range of nano and micro scale filler particles to give an average particle size of 0.6 mum, while the second is a nanofill composite reinforced entirely with nano particles and their agglomerates. The influences of 60 days water hydration and a post-cure heat treatment were also examined. Fracture resistance curve (R-curve) experiments have demonstrated the microhybrid composite to be more fracture resistant than the nanofill composite in both as-processed and hydrated conditions. Rising fracture resistance with crack extension was observed in all specimens, independent of the environmental conditions. Compared to the as-processed condition, a significant reduction in the peak toughness was observed for the nanofill composite after 60 days of water aging. Hydration lowered flexural strength of both composites which was attributed to hydrolytic matrix degradation with additional interfacial debonding causing larger strength decrease in the nanofill. Optical and SEM observations revealed an interparticle matrix crack path promoting crack deflection as a toughening mechanism in all cases except the hydrated nanofill which showed particle-matrix debonding. Crack bridging was another observed extrinsic toughening mechanism that was believed to be responsible for the rising fracture resistance curve (R

  7. Streambed Composition and its Contribution to Spawning Viability Following the Completion of the Stoney Creek Weir Restoration Project

    OpenAIRE

    Schneider, Kurt (Ed.); Byrne, Shane; Drover, Alicia; Van Pelt, Ginny; Liu, Kitty

    2013-01-01

    Salmon populations are highly endangered, and in an attempt to restore these populations, habitat restoration projects have become abundant. The Stoney Creek Environment Committee established one such project to enhance salmon spawning conditions at Stoney Creek in Burnaby, BC, by building three weirs. In this report, the streambed composition of the three weirs is analyzed in relation to salmon spawning conditions for the five species of Salmonidea present in Stoney Creek. The result is a nu...

  8. Curriculum time compared to clinical procedures in amalgam and composite posterior restorations in U.S. dental schools: a preliminary study.

    Science.gov (United States)

    Rey, Rosalia; Nimmo, Susan; Childs, Gail S; Behar-Horenstein, Linda S

    2015-03-01

    Dental clinicians have an expanding range of biomaterial choices for restoring tooth structure. Scientific developments in cariology, advances in dental biomaterials, and patients' esthetic concerns have led to a reduction in amalgam restorations and an increase in composite restorations. The aim of this study was to compare teaching time with students' clinical procedures in amalgam and composite posterior restorations in dental schools across the United States. Academic deans in 60 schools were invited to complete a survey that asked for the amount of instructional time for amalgam and composite posterior restorations and the number of clinical restorations performed by their Classes of 2009, 2010, and 2011. Of these 60, 12 returned surveys with complete data, for a 20% response rate. Responses from these schools showed little change in lecture and preclinical laboratory instruction from 2009 to 2011. There was a slight increase in two-surface restorations for both amalgam and composites; however, the total number of reported composite and amalgam restorations remained the same. Of 204,864 restorations reported, 53% were composite, and 47% were amalgam. There were twice as many multisurface large or complex amalgam restorations as composites. One-surface composite restorations exceeded amalgams. Among the participating schools, there was little to no change between curriculum time and clinical procedures. Findings from this preliminary study reflect a modest increase in two-surface resin-based restorations placed by dental students from 2009 to 2011 and little change in curricular time devoted to teaching amalgam restorations. The total number of posterior composite restorations placed by students in these schools was slightly higher than amalgams.

  9. An evaluation of strength of composite resin restorations using different bonding agents--an in-vitro study.

    Science.gov (United States)

    Ansari, A A

    2004-01-01

    In the recent years, the scope of conservative dentistry with emphasis on esthetics has increased by leaps and bounds in enhancing individual personality. Composite resins are important for aesthetic restorations in dentistry, specifically in operative dentistry. But without bonding agents the success of composite restorations is minimized. Researchers are constantly endeavoring to improve the quality of bonding agents. The advent of new bonding systems which are capable of bonding both enamel & dentin has opened new avenues in the field of restorative dentistry. With the market floating with new bonding agents claiming superior bonding properties, this study was undertaken to investigate the degree of bond strength produced by three commercially available bonding agents (Syntac, Scotchbond 1, & Clearfil SE) with composite resin (Esthet-X) taken for the experimental procedure. PMID:15855709

  10. Assessing ex vivo dental biofilms and in vivo composite restorations using cross-polarization optical coherence tomography

    Science.gov (United States)

    Jones, R.; Aparicio, C.; Chityala, R.; Chen, R.; Fok, A.; Rudney, J.

    2012-01-01

    A cross-polarization 1310-nm optical coherence tomography system (CP-OCT), using a beam splitter based design, was used to assess ex vivo growth of complex multi-species dental biofilms. These biofilm microcosms were derived from plaque samples along the interface of composite or amalgam restoration in children with a history of early childhood caries. This paper presents a method of measuring the mean biofilm height of mature biofilms using CP-OCT. For our in vivo application, the novel swept source based CP-OCT intraoral probe (Santec Co. Komaki, Japan) dimensions and system image acquisition speed (20 image frames/second) allowed imaging pediatric subjects as young as 4 years old. The subsurface enamel under the interface of composite resin restorations of pediatric subjects were imaged using CP-OCT. Cavitated secondary caries is clearly evident from sound resin composite restorations.

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

    OpenAIRE

    Khoroushi, Maryam; Shirban, Farinaz; Sahraneshin-Samani, Mahsa

    2016-01-01

    Background Moisture control is very important in restorative procedures in dentistry. Use of hemostatic agents helps control moisture; however, they might result in changes on enamel and dentin surfaces, affecting composite resin bond quality. The aim of this in vitro study was to evaluate the marginal microleakage of two different composite resins with the use of three different hemostatic agents. Material and Methods Standardized Class V cavities were prepared on the buccal and lingual surf...

  12. Comparison of shear bond strengths of conventional orthodontic composite and nano-ceramic restorative composite: An in vitro study

    Directory of Open Access Journals (Sweden)

    Namit Nagar

    2013-01-01

    Full Text Available Objectives: To compare the shear bond strength of a nano-ceramic restorative composite Ceram-X MonoTM♦, a restorative resin with the traditional orthodontic composite Transbond XTTM† and to evaluate the site of bond failure using Adhesive Remnant Index. Materials and Methods: Sixty extracted human premolars were divided into two groups of 30 each. Stainless steel brackets were bonded using Transbond XTTM† (Group I and Ceram-X MonoTM♦ (Group II according to manufacturer′s protocol. Shear bond strength was measured on Universal testing machine at crosshead speed of 1 mm/minute. Adhesive Remnant Index scores were assigned to debonded brackets of each group. Data was analyzed using unpaired ′t′ test and Chi square test. Results: The mean shear bond strength of Group I (Transbond XTTM† was 12.89 MPa ± 2.19 and that of Group II (Ceram-X MonoTM was 7.29 MPa ± 1.76. Unpaired ′t′ test revealed statistically significant differences amongst the shear bond strength of the samples measured. Chi-square test revealed statistically insignificant differences amongst the ARI scores of the samples measured. Conclusions: Ceram-X MonoTM♦ had a lesser mean shear bond strength when compared to Transbond XTTM† which was statistically significant difference. However, the mean shear bond of Ceram X Mono was within the clinically acceptable range for bonding. Ceram-X MonoTM† and Transbond XTTM† showed cohesive fracture of adhesive in 72.6% and 66.6% of the specimens, respectively.

  13. Replacement of Anterior Composite Resin Restorations Using Conservative Ceramics for Occlusal and Periodontal Rehabilitation: An 18-Month Clinical Follow-Up.

    Science.gov (United States)

    da Cunha, Leonardo Fernandes; Prochnow, Rayane Alexandra; Costacurta, Adriana Osten; Gonzaga, Carla Castiglia; Correr, Gisele Maria

    2016-01-01

    This case report describes a patient with discolored and fractured composite resin restorations on the anterior teeth in whom substitution was indicated. After wax-up and mock-up, the composite was removed and replaced with minimally invasive ceramic laminates. An established and predictable protocol was performed using resin cement. Minimally invasive ceramic restorations are increasingly being used to replace composite restorations. This treatment improves the occlusal and periodontal aspects during the planning and restorative phases, such as anterior guides, and laterality can be restored easily with ceramic laminates. In addition, the surface smoothness and contour of ceramic restorations do not affect the health of the surrounding periodontal tissues. Here we present the outcome after 18 months of clinical follow-up in a patient in whom composite resin restorations in the anterior teeth were replaced with minimally invasive ceramic laminates. PMID:27555970

  14. Replacement of Anterior Composite Resin Restorations Using Conservative Ceramics for Occlusal and Periodontal Rehabilitation: An 18-Month Clinical Follow-Up

    Directory of Open Access Journals (Sweden)

    Leonardo Fernandes da Cunha

    2016-01-01

    Full Text Available This case report describes a patient with discolored and fractured composite resin restorations on the anterior teeth in whom substitution was indicated. After wax-up and mock-up, the composite was removed and replaced with minimally invasive ceramic laminates. An established and predictable protocol was performed using resin cement. Minimally invasive ceramic restorations are increasingly being used to replace composite restorations. This treatment improves the occlusal and periodontal aspects during the planning and restorative phases, such as anterior guides, and laterality can be restored easily with ceramic laminates. In addition, the surface smoothness and contour of ceramic restorations do not affect the health of the surrounding periodontal tissues. Here we present the outcome after 18 months of clinical follow-up in a patient in whom composite resin restorations in the anterior teeth were replaced with minimally invasive ceramic laminates.

  15. Replacement of Anterior Composite Resin Restorations Using Conservative Ceramics for Occlusal and Periodontal Rehabilitation: An 18-Month Clinical Follow-Up

    Science.gov (United States)

    Prochnow, Rayane Alexandra; Costacurta, Adriana Osten; Correr, Gisele Maria

    2016-01-01

    This case report describes a patient with discolored and fractured composite resin restorations on the anterior teeth in whom substitution was indicated. After wax-up and mock-up, the composite was removed and replaced with minimally invasive ceramic laminates. An established and predictable protocol was performed using resin cement. Minimally invasive ceramic restorations are increasingly being used to replace composite restorations. This treatment improves the occlusal and periodontal aspects during the planning and restorative phases, such as anterior guides, and laterality can be restored easily with ceramic laminates. In addition, the surface smoothness and contour of ceramic restorations do not affect the health of the surrounding periodontal tissues. Here we present the outcome after 18 months of clinical follow-up in a patient in whom composite resin restorations in the anterior teeth were replaced with minimally invasive ceramic laminates. PMID:27555970

  16. A retrospective clinical evaluation of success rate in endodontic-treated premolars restored with composite resin and fiber reinforced composite posts

    Directory of Open Access Journals (Sweden)

    Marjaneh Ghavamnasiri

    2011-01-01

    Full Text Available Background : The aim of this retrospective study was to assess the survival rate and causes of failure of quartz fiber posts used to restore endodontically treated teeth. Materials and Methods : Thirty-eight patients with endodontically treated premolar and anterior teeth that were then restored with a coronoradicular quartz fiber post and extensive composite resin restorations were selected for participation in the study. The age of the restorations ranged from 1 to 6 years. Survival probabilities of the restorations as well as causes of failures were analyzed using the Kaplan-Meier analysis and the Logistic regression (α = 0.05. Results : The overall cumulative survival rate (48.8% was determined, while the survival probabilities after 1, 2, 4, 5, and 6 years of service were 88.37%, 60.95%, 45.71%, 32.65%, and 0%, respectively. Conclusions : The survival probability of endodontically treated teeth restored with a quartz fiber post and composite restorations is associated with the dental arch.

  17. The effect of insertion and photopolymerization techniques on microleakage of Class V cavities: a quantitative evaluation Efeito de diferentes técnicas de inserção e fotopolimerização na microinfiltração de cavidades Classe V: avaliação quantitativa

    Directory of Open Access Journals (Sweden)

    Fabiana Mantovani Gomes França

    2005-03-01

    Full Text Available The aim of this in vitro study was to evaluate by spectrophotometry the influence of the incremental technique and progressive light curing in the microleakage of Class V cavities. Forty samples were prepared with class V cylindrical cavities on the buccal root surface of bovine incisive teeth and filled with composite resin (Z250. The samples were divided into four groups: I: cavity was bulk filled and the composite was light cured for 40 seconds; Group II: cavity was bulk filled and a "soft-start" polymerization was used; Group III: cavity was filled with the incremental technique in two coats and light cured for 40 seconds; Group IV: cavity was filled with the incremental technique in two coats and light cured with "soft-start" polymerization. After the restoration, the specimens were thermally stressed for 3,000 cycles in bath at 5 ± 2°C and 55 ± 2°C, protected with nail enamel, colored with 2% methylene blue and cut into sections. These sections were triturated and the dye was recovered with PA ethanol and the supernatant was evaluated. The data were submitted to ANOVA and the results showed the following averages: bulk filled and conventional photopolymerization (I 0.06075 µg/ml; bulk filled and progressive photopolymerization (II 0.04030 µg/ml; incremental insertion and conventional photopolymerization (III 0.04648 µg/ml; incremental insertion and progressive photopolymerization (IV 0.04339 µg/ml. No significant statistic differences were observed among the mean values. The Degulux "soft-start" equipment probably emits too high initial light intensity to promote progressive photopolymerization.O objetivo deste estudo in vitro foi avaliar através de espectrofotometria a influência das técnicas de inserção incremental e de fotopolimerização progressiva na microinfiltração de cavidades Classe V. Foram preparadas 40 cavidades cilíndricas na superfície radicular vestibular de incisivos bovinos e preenchidas com resina

  18. Development of caries adjacent to composite restorations after exposure to dentifrices with different fluoride concentrations

    Directory of Open Access Journals (Sweden)

    Dayse Andrade Romão

    Full Text Available Objective To evaluate the development of recurrent caries after exposure to fluoride dentifrices with different concentrations. Material and method: 48 samples of bovine incisors (4x4mm2 were exposed to pH cycling for 7 days before the preparation of the cavities (2mm deep. The samples were restored with a microhybrid resin composite. Then, the samples were exposed to thermal cycling (350 cycles and they were randomly allocated into 4 treatment groups (n = 12: Group A - non-fluoridated dentifrice (negative control; Group B - 500 ppm dentifrice; Group C - 750 ppm dentifrice; group D - 1100 ppm dentifrice (positive control. The samples were treated with solutions of each dentifrice (9.6 ml water/1.6 g dentifrice for 60 seconds and then were immersed in demineralizing (3 h and remineralizing (2 h solutions 3 times a day. Next, the samples were immersed in a remineralizing solution for 18 hours. Then, the blocks were sectioned for examination of the length of the outer caries lesion, using polarized light microscopy. The ANOVA parametric test complemented by the Tukey test with a confidence level of 95%, were used in the statistical analysis. Result: A smaller lesion length was observed in the group treated with the fluoride concentration of 1100 ppm F, but there were no differences between toothpastes with fluoride concentrations of 500 and 750 ppm F. Conclusion: The use of fluoride dentifrices (1100 ppm reduces the development of caries adjacent to dental restorations.

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

    Science.gov (United States)

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

    2015-01-01

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

  20. Comparative Evaluation of Microleakage Between Nano-Ionomer, Giomer and Resin Modified Glass Ionomer Cement in Class V Cavities- CLSM Study

    Science.gov (United States)

    Hari, Archana; Thumu, Jayaprakash; Velagula, Lakshmi Deepa; Bolla, Nagesh; Varri, Sujana; Kasaraneni, Srikanth; Nalli, Siva Venkata Malathi

    2016-01-01

    Introduction Marginal integrity of adhesive restorative materials provides better sealing ability for enamel and dentin and plays an important role in success of restoration in Class V cavities. Restorative material with good marginal adaptation improves the longevity of restorations. Aim Aim of this study was to evaluate microleakage in Class V cavities which were restored with Resin Modified Glass Ionomer Cement (RMGIC), Giomer and Nano-Ionomer. Materials and Methods This in-vitro study was performed on 60 human maxillary and mandibular premolars which were extracted for orthodontic reasons. A standard wedge shaped defect was prepared on the buccal surfaces of teeth with the gingival margin placed near Cemento Enamel Junction (CEJ). Teeth were divided into three groups of 20 each and restored with RMGIC, Giomer and Nano-Ionomer and were subjected to thermocycling. Teeth were then immersed in 0.5% Rhodamine B dye for 48 hours. They were sectioned longitudinally from the middle of cavity into mesial and distal parts. The sections were observed under Confocal Laser Scanning Microscope (CLSM) to evaluate microleakage. Depth of dye penetration was measured in millimeters. Statistical Analysis The data was analysed using the Kruskal Wallis test. Pair wise comparison was done with Mann Whitney U Test. A p-value<0.05 is taken as statistically significant. Results Nano-Ionomer showed less microleakage which was statistically significant when compared to Giomer (p=0.0050). Statistically no significant difference was found between Nano Ionomer and RMGIC (p=0.3550). There was statistically significant difference between RMGIC and Giomer (p=0.0450). Conclusion Nano-Ionomer and RMGIC showed significantly less leakage and better adaptation than Giomer and there was no statistically significant difference between Nano-Ionomer and RMGIC. PMID:27437363

  1. Microleakage and Micrographic Evaluation of Composite Restorations With Various Bases Over ZOE Layer in Pulpotomized Primary Molars

    Directory of Open Access Journals (Sweden)

    M. Rezamand

    2011-12-01

    Full Text Available Objective: Zinc oxide eugenol (ZOE under composite restorations should be covered with a suitable material in order to prevent the harmful effect of ZOE on the composite. The aim of this in vitro study was to evaluate microleakage of composite restorations in pulpotomized primary molars with different bases for covering the ZOE layer and to assess the distance between different layers.Materials and Methods: Proximo-occlusal cavities were prepared in 78 extracted second primary molars. Carious lesions were removed and pulpotomy was carried out. Zinc oxide eugenol paste was placed in 2-mm thickness. The teeth were randomly divided in 6 groups and restored as follows: 1. Light-cured composite; 2. Resin-modified glass-ionomer and composite resin; 3. Glass-ionomer and composite resin; 4. Light-cured calcium hydroxide and composite resin; 5.Calcium hydroxide and composite resin; 6. Amalgam and composite resin. The restored specimens were thermocycled for 500 cycles (5°C/55°C and microleakage was assessed by dye penetration technique. Three specimens from each group were processed for scanning electron microscope evaluation to determine the distance between the layers. The results were analyzed by Kruskal-Wallis and Dunn tests.Results: Microleakage assessment revealed significant differences between the groups (P=0.04, with the amalgam group exhibiting the lowest microleakage values. In SEM micrographs no significant differences were observed in the distance between ZOE base layers (P=0.94 and base-composite layers (P=0.47; however, the amalgam group had the lowest distances.Conclusion: The use of amalgam over zinc oxide eugenol layer in pulpotomized primary molars decreases microleakage.

  2. Have wet meadow restoration projects in the Southwestern U.S. been effective in restoring geomorphology, hydrology, soils, and plant species composition?

    Directory of Open Access Journals (Sweden)

    Ramstead Karissa M

    2012-09-01

    Full Text Available Abstract Background Wet meadows occur in numerous locations throughout the American Southwest, but in many cases have become heavily degraded. Among other things they have frequently been overgrazed and have had roads built through them, which have affected the hydrology of these wetland ecosystems. Because of the important hydrologic and ecological functions they are believed to perform, there is currently significant interest in wet meadow restoration. Several restoration projects have been completed recently or are underway in the region, sometimes at considerable expense and with minimal monitoring. The objective of this review was to evaluate the effects of wet meadow restoration projects in the southwestern United States on geomorphology, hydrology, soils and plant species composition. A secondary objective was to determine the effects of wet meadow restoration projects on wildlife. Methods Electronic databases, internet search engines, websites and personal contacts were used to find articles of relevance to this review. Articles were filtered by title, abstract and full text. Summary information for each of the articles remaining after the filtering process was compiled and used to assess the quality of the evidence presented using two different approaches. Results Our searches yielded 48 articles, of which 25 were published in peer-reviewed journals, 14 were monitoring or project reports, and 9 were published in conference proceedings or are unpublished theses or manuscripts. A total of 26 operational-scale restoration projects were identified. A wide range of restoration techniques were employed, ranging from small-scale manipulations of stream channels (e.g., riffle structures to large scale pond-and-plug projects. Other common restoration techniques included fencing to exclude livestock (and sometimes also native ungulates, other forms of grazing management, seeding, and transplanting seedlings. Most of the articles reported that

  3. Do resin cements influence the cuspal deflection of teeth restored with composite resin inlays?

    Science.gov (United States)

    da Rosa, Helen C V; Marcondes, Maurem L; de Souza, Niélli C; Weber, João B B; Spohr, Ana M

    2015-04-01

    The aim of this study was to evaluate the influence of different resin cements on the cuspal deflection of endodontically treated teeth restored with composite resin inlays. Sixty upper premolars were randomly divided into five groups (n=12): 1 - sound teeth; 2 - cavity; 3 - Rely X ARC; 4 - RelyX Unicem; 5 - SeT. The teeth from groups 2, 3, 4 and 5 received a MOD preparation and endodontic treatment. Impressions were made with vinyl polysiloxane and poured using type IV die stone in groups 3, 4 and 5. Inlays with composite resin were built over each cast and luted with the resin cements. A 200 N load was applied on the occlusal surface, and cuspal deflection was measured using a micrometer. After 24 h, cuspal deflection was measured again using a 300 N load. The Student t-test showed that there was no statistically significant difference between the 200 N and 300 N occlusal loads only for the sound teeth group (p = 0.389) and the RelyX ARC group (p = 0.188). ANOVA and Tukey'test showed that the sound teeth had the lowest mean cuspal deflection, differing statistically from the other groups (p<0.05). The highest cuspal deflections were obtained in the SeT group and the cavity group, with no statistical difference between them. Intermediate values were obtained in RelyX ARC group and RelyX Unicem group, which differed statistically. The self-adhesive resin cements RelyX Unicem and SeT showed less capacity to maintain the stiffness of the tooth/restoration complex than the conventional resin cement RelyX ARC. PMID:25950160

  4. Evaluation of Gingival Microleakage in Class II Composite Restorations with Different Lining Techniques: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Vedavathi Bore Gowda

    2015-01-01

    Full Text Available Aim. To compare the microleakage in class II composite restorations without a liner/with resin modified glass ionomer and flowable composite liner. Method. Forty standardized MO cavities were prepared on human permanent mandibular molars extracted for periodontal reasons and then divided into 4 groups of ten specimens. The cavity preparations were etched, rinsed, blot dried, and light cured and Adper Single Bond 2 is applied. Group 1 is restored with Filtek P60 packable composite in 2 mm oblique increments. Group 2 is precure group where 1 mm Filtek Z350 flowable liner is applied and light cured for 20 sec. Group 3 is the same as Group 2, but the liner was cocured with packable composite. In Group 4, 1 mm RMGIC, Fuji Lining LC is applied and cured for 20 sec. All the teeth were restored as in Group 1. The specimens were coated with nail varnish leaving 1 mm around the restoration, subjected to thermocycling, basic fuchsin dye penetration, sectioned mesiodistally, and observed under a stereomicroscope. Results. The mean leakage scores of the individual study groups were Group 1 (33.40, Group 2 (7.85, Group 3 (16.40, and Group 4 (24.35. Group 1 without a liner showed maximum leakage. Flowable composite liner precured was the best.

  5. Influence of microleakage, surface roughness and biofilm control on secondary caries formation around composite resin restorations: an in situ evaluation

    Directory of Open Access Journals (Sweden)

    Fábio Garcia Lima

    2009-02-01

    Full Text Available This study was carried out to evaluate in situ the influence of microleakage, surface roughness and biofilm control on caries formation around composite resin restorations. During 28 days, 12 volunteers wore palatal devices containing bovine enamel slabs restored with composite resin. Restorations were made without leakage, when the adhesive system was applied, or with leakage, when adhesive system was omitted. Half of the restorations in each group were finished and the remaining were finished and polished. In one side of the palatal device, biofilm was left to accumulate over the restored slabs, and in the other side dental slabs were brushed, to allow biofilm removal. There was an extraoral application of 20% sucrose solution (8x/day over the enamel slabs. The formation of caries lesions (white spots was evaluated by visual inspection under stereomicroscopy. Additionally, the dental slabs were sectioned and observed under polarized light microscopy. Data were submitted to Kruskal-Wallis test and Spearman's correlation test at 5% significance level. Polishing and bonding were not significant factors regarding white spot formation (p>0.05. Biofilm control (brushing was associated with reduction of caries formation close to the restorations (p<0.01. Polarized light microscopy confirmed the visual inspection findings. These results suggest that while microleakage and surface roughness did not influence caries lesion formation, biofilm control may prevent the enamel demineralization.

  6. A new system for posterior restorations: a combination of ceramic optimized polymer and fiber-reinforced composite.

    Science.gov (United States)

    Rosenthal, L; Trinkner, T; Pescatore, C

    1997-01-01

    Due to the need for increased strength characteristics and enhanced aesthetic expectations of the patients, metal-free, aesthetic restorative systems for the anterior and posterior dentition are currently available. A new "space-age" restorative material has been developed that is a combination of a ceramic optimized polymer (Ceromer) (Targis/Vectris, Ivoclar Williams, Amherst, NY) and a fiber-reinforced composite framework material. The purpose of this article is to discuss the qualities that render this material particularly suitable for a variety of indications, including laboratory-fabricated restorations for the stress-bearing posterior regions. The material lends itself to diversification. Its indication for inlays, onlays, full-coverage crown restorations, and conservative single pontic inlay bridges is presented.

  7. Restoration of Natural Frequency of Cracked Cantilever Beam Using CNT Composite Patch: A Finite Element Study

    Directory of Open Access Journals (Sweden)

    Mahmoud Nadim Nahas

    2013-01-01

    Full Text Available Cyclic loadings cause fatigue to the elements of machines leading to crack initiation and propagation. This phenomenon decreases the age of the elements. In particular, cracks decrease the stiffness of the parts and lower the parts natural frequency, leading to failure under normal working conditions. This paper introduces a new application to carbon nanotube (CNT composites in the repairing process of a cracked specimen to restore the natural frequency of the specimen. Commonly, patches are made of high strength and high stiffness materials. This paper shows that even low stiffness materials, such as epoxy reinforced with CNT, can contribute to the repair of a cracked specimen. A 2D finite element (FE simulation is used to study the effects of bonding CNT composite patches over the crack location to repair cracked metal specimens. The effects of the patch thickness, length, and CNTs weight concentration ratio are investigated. Results showed an increase in the natural frequency of 31% compared to the cracked specimen at a crack depth of 70% of the beam depth and at a distance of 20% of the total beam length from the support.

  8. 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

  9. A class V chitinase from Arabidopsis thaliana: gene responses, enzymatic properties, and crystallographic analysis

    DEFF Research Database (Denmark)

    Ohnuma, Takayuki; Numata, Tomoyuki; Osawa, Takuo;

    2011-01-01

    Expression of a class V chitinase gene (At4g19810, AtChiC) in Arabidopsis thaliana was examined by quantitative real-time PCR and by analyzing microarray data available at Genevestigator. The gene expression was induced by the plant stress-related hormones abscisic acid (ABA) and jasmonic acid (J...

  10. An In-vitro Evaluation of Effects of Light and Light-Heat Curing Inlay Composite Restorations on Fracture Resistance of Pulpless Maxillary Premolars

    OpenAIRE

    M Mousavinasab; S. Ashrafijoo

    2004-01-01

    Statement of Problem: The restoration of the teeth should have enough ability to withstand masticator forces while preserving as much tooth structure as possible.Purpose: The purpose of this study was to compare the effects of light-heat cured composite with light cured composite restorations on fracture resistance of the restored teeth.Materials and Methods: Forty healthy maxillary premolar teeth were chosen, endodontic treatment performed in 30 of them. MOD cavities were prepared in all of ...

  11. Restoration of the immune functions in aged mice by supplementation with a new herbal composition, HemoHIM.

    Science.gov (United States)

    Park, Hae-Ran; Jo, Sung-Kee; Jung, Uhee; Yee, Sung-Tae

    2008-01-01

    The effect of a new herbal composition, HemoHIM, on immune functions was examined in aged mice, in which various immune responses had been impaired. The composition HemoHIM was prepared by adding the ethanol-insoluble fraction to the total water extract of a mixture of three edible herbs, Angelica Radix, Cnidium Rhizoma and Paeonia Radix. Supplementation to the aged mice with HemoHIM restored the proliferative response and cytokine production of splenocytes with a response to ConA. Also, HemoHIM recovered the NK cell activity which had been impaired in the aged mice. Meanwhile aging is known to reduce the Th1-like function, but not the Th2-like function, resulting in a Th1/Th2 imbalance. HemoHIM restored the Th1/Th2 balance in the aged mice through enhanced IFN-gamma and IgG2a production, and conversely a reduced IL-4 and IgG1 production. It was found that one factor for the Th1/Th2 imbalance in the aged mice was a lower production of IL-12p70. However, HemoHIM restored the IL-12p70 production in the aged mice. These results suggested that HemoHIM was effective for the restoration of impaired immune functions of the aged mice and therefore could be a good recommendation for immune restoration in elderly humans. PMID:17705143

  12. Restoration of the immune functions in aged mice by supplementation with a new herbal composition, HemoHIM.

    Science.gov (United States)

    Park, Hae-Ran; Jo, Sung-Kee; Jung, Uhee; Yee, Sung-Tae

    2008-01-01

    The effect of a new herbal composition, HemoHIM, on immune functions was examined in aged mice, in which various immune responses had been impaired. The composition HemoHIM was prepared by adding the ethanol-insoluble fraction to the total water extract of a mixture of three edible herbs, Angelica Radix, Cnidium Rhizoma and Paeonia Radix. Supplementation to the aged mice with HemoHIM restored the proliferative response and cytokine production of splenocytes with a response to ConA. Also, HemoHIM recovered the NK cell activity which had been impaired in the aged mice. Meanwhile aging is known to reduce the Th1-like function, but not the Th2-like function, resulting in a Th1/Th2 imbalance. HemoHIM restored the Th1/Th2 balance in the aged mice through enhanced IFN-gamma and IgG2a production, and conversely a reduced IL-4 and IgG1 production. It was found that one factor for the Th1/Th2 imbalance in the aged mice was a lower production of IL-12p70. However, HemoHIM restored the IL-12p70 production in the aged mice. These results suggested that HemoHIM was effective for the restoration of impaired immune functions of the aged mice and therefore could be a good recommendation for immune restoration in elderly humans.

  13. In vitro evaluation of microleakage of class II packable composite resin restorations using flowable composite and resin modified glass ionomers as intermediate layers

    OpenAIRE

    Kishore Kumar Majety; Madhu Pujar

    2011-01-01

    Aim and Objectives : To evaluate the cervical marginal microleakage of class II packable composite resin restorations using flowable composite and resin modified glass ionomer as intermediate layers and whether the difference in the thickness of these intermediate layers would influence the microleakage. Materials and Methods : Standardized class II box only cavities (4 mm bucco lingual width 2 mm mesio distal depth with the gingival margin 1 mm above the cemento-enamel junction (CEJ) wer...

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Comparison of fracture resistance of endodontically treated teeth restored with nanohybrid, silorane, and fiber reinforced composite: An in vitro study

    Science.gov (United States)

    Bilgi, Priyanka Shripad; Shah, Nimisha Chinmay; Patel, Parth Pinakinbhai; Vaid, Deepa S

    2016-01-01

    Background: The present study was undertaken to evaluate the most suitable restorative for badly mutilated endodontically treated teeth. Aims: To evaluate and compare the fracture resistance of endodontically treated premolars restored with conventional nanohybrid, silorane composite with glass fibers and newer fiber-reinforced composite in mesio-occluso-distal (MOD) cavities. Materials and Methods: Sixty extracted human maxillary premolars were selected. Fifteen intact teeth served as positive controls (Group 1). Endodontic therapy was done in the remaining 45 teeth. MOD cavities were prepared in all the teeth with standardized dimensions and were randomly divided into three groups (Group 2 - nanohybrid + glass fibers, Group 3 - silorane + glass fibers, and Group 4 – fiber-reinforced composite). Restorations were done for all groups. Fracture resistance was measured by Instron universal testing machine. Statistical Analysis Used: One-way anova test and Tukey's post hoc test. Results: Highest fracture resistance was shown by intact teeth group followed by fiber-reinforced composite, nanohybrid, and silorane, respectively. Statistically Significant difference was revealed by anova test (P composite showed the highest fracture resistance. Statistically significant difference was observed for all the groups. PMID:27563188

  16. Effect of Cavity Design on the Strength of Direct Posterior Composite Restorations: An Empirical and FEM Analysis.

    Science.gov (United States)

    Anand, V Susila; Kavitha, C; Subbarao, C V

    2011-01-01

    The aim of the present study was to verify the hypothesis that cavity design does not affect the strength of direct composite restorations as do material properties. Finite element modeling (FEM) and empirical testing were done for two cavity designs: a box shape (cube) and a concave shape (U). Two microhybrid composites were used to prepare the samples with the help of split stainless steel moulds. Compressive strength was tested. The results were statistically analyzed. Both FEA and empirical testing were complementary to each other in that the concave shape showed a significantly higher strength than box. Material properties affected the values only when box shape was used. The null hypothesis is thus rejected, and it is concluded that design significantly affects the strength of direct composite restorations. PMID:22216030

  17. Effect of Cavity Design on the Strength of Direct Posterior Composite Restorations: An Empirical and FEM Analysis

    Directory of Open Access Journals (Sweden)

    V. Susila Anand

    2011-01-01

    Full Text Available The aim of the present study was to verify the hypothesis that cavity design does not affect the strength of direct composite restorations as do material properties. Finite element modeling (FEM and empirical testing were done for two cavity designs: a box shape (cube and a concave shape (U. Two microhybrid composites were used to prepare the samples with the help of split stainless steel moulds. Compressive strength was tested. The results were statistically analyzed. Both FEA and empirical testing were complementary to each other in that the concave shape showed a significantly higher strength than box. Material properties affected the values only when box shape was used. The null hypothesis is thus rejected, and it is concluded that design significantly affects the strength of direct composite restorations.

  18. The influence of the cavity preparation design on marginal accuracy of laboratory-processed resin composite restorations.

    Science.gov (United States)

    Fonseca, Rodrigo Borges; Correr-Sobrinho, Lourenço; Fernandes-Neto, Alfredo Júlio; Quagliatto, Paulo Sérgio; Soares, Carlos José

    2008-03-01

    The aim of this study was to evaluate the influence of different cavity preparation designs on marginal accuracy of laboratory-processed resin composite restored teeth. Eighty mandibular human third molars were selected. There were two experimental factors, occlusal isthmus width (narrow vs wide) and cuspal coverage (inlay, one-cusp onlay, two-cusp onlay, and all-cusp onlay), resulting on eight groups (N = 10). Indirect composite restorations (SR Adoro, Ivoclar-Vivadent) were manufactured and positioned over each respective preparation. Marginal accuracy evaluation was accomplished using a stereomicroscope at three points on buccal, lingual, mesial, and distal regions with 40x magnification. The results showed significant differences (P = 0.00) with wide inlay showing the best overall marginal accuracy and narrow inlay the worst one. Two-way analysis of variance (ANOVA) showed significant differences when considering the factor occlusal isthmus width (P = 0.00). In general, preparations with wide occlusal isthmus presented better results than narrow ones, except for wide all-cusp onlays; however, the test failed to show differences when considering the cuspal coverage (P = 0.42) or the interaction between both factors (P = 0.30). The effect of occlusal width extension on marginal accuracy of indirect composite resin restorations is significant, with lower values of gaps width in wide preparations, but since in a clinical situation this would mean greater removal of sound tooth structure, less-aggressive preparations combined with other restorative procedures seem to be more feasible.

  19. Effect of Er,Cr:YSGG laser on the surface of composite restoratives during in-office tooth bleaching.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Strakas, Dimitrios; Tsitrou, Effrosyni; Tolidis, Kosmas; Koumpia, Effimia

    2016-07-01

    The aim of this in vitro study was to investigate the effect of Er,Cr:YSGG laser on the surface roughness and microhardness of various composite restoratives during in-office tooth bleaching. Five highly viscous composite restoratives and three flowable composite restoratives were investigated. Thirty cylindrical specimens of each material were made using Teflon molds. The specimens of each composite were randomly divided into three groups (n = 10). Group 1 specimens did not receive bleaching treatment, group 2 received a conventional in-office bleaching treatment, and group 3 received a laser-assisted in-office bleaching treatment using an Er,Cr:YSGG laser. Two-way ANOVA was used to determine significant interactions between materials and bleaching methods. One-way ANOVA and Tukey's post hoc test were used to compare the mean surface microhardness and roughness between materials for each treatment group (a = 0.05). Τhere were no significant differences in surface microhardness between the two bleached experimental groups for all the tested composites (p > 0.05). The reduction of surface microhardness after bleaching procedures ranged from 0.72 to 16.93 % for the specimens received conventional treatment and from 1.30 to 11.51 % for those received laser-assisted treatment. Moreover, there were no significant differences in Ra values between the experimental groups (p > 0.05) in all cases. The increase of surface roughness after the bleaching treatments was negligible and was between 0.43 and 4.78 %. The use of Er,Cr:YSGG laser during in-office tooth bleaching treatment did not affect the surface microhardness and roughness of the tested composite restorative materials.

  20. Class I and Class II restorations of resin composite: an FE analysis of the influence of modulus of elasticity on stresses generated by occlusal loading

    DEFF Research Database (Denmark)

    Asmussen, Erik; Peutzfeldt, Anne

    2008-01-01

    OBJECTIVES: It was the aim of the study to analyze by the FE method stresses generated in tooth and restoration by occlusal loading of Class I and Class II restorations of resin composite. On the basis of available information on the influence of the modulus of elasticity, the research hypothesis...... was that the marginal stresses would decrease with increasing modulus of elasticity of the restoration. METHODS: A cylindrical tooth was modelled in enamel and dentin and fitted with a Class I or a Class II restoration of resin composite. In one scenario the restoration was bonded to the tooth, in another...... the restoration was left nonbonded. The resin composite was modelled with a modulus of elasticity of 5, 10, 15 or 20 GPa and loaded occlusally with 100 N. By means of the soft-ware program ABAQUS the von Mises stresses in enamel and dentin were calculated. RESULTS: In the bonded scenario, the maximum stresses...

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

    Science.gov (United States)

    Blixt, M; Coli, P

    1993-03-01

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

  2. Microleakage of composite resin restoration in cavities prepared by Er:YAG laser irradiation in primary teeth.

    Science.gov (United States)

    Yamada, Y; Hossain, M; Nakamura, Y; Murakami, Y; Matsumoto, K

    2002-03-01

    AIM: The purposes of this study were to investigate the surface morphology of cavities prepared by Er:YAG laser irradiation and to compare the microleakage degree after composite resin restoration with etched bur cavities in primary teeth, in vitro. MATERIALS AND METHODS: On the buccal (facial) and lingual (palatal) surfaces of 25 primary teeth, a round cavity was prepared with the Er:YAG laser system and with a high-speed diamond bur, respectively. Five cavities from each group were investigated by scanning electron microscopy (SEM). The remaining cavities were filled with a composite resin and subjected to a microleakage test (0.6% rodamine B solution) under thermocycling. Only bur cavities were acid-etched before filling. Statistical analysis was performed using the Mann-Whitney's U test; a value of p adhesion between the restorative material and dental hard tissues; there was also no gap at the interface. DISCUSSION: The highly irregular surface or the removal of the debris-like smear layer after laser irradiation may facilitate good adhesion of composite resin with enamel or dentine, and these surfaces might play a major role in decreasing microleakage of laser cavities. CONCLUSION: It can be concluded that cavities prepared by Er:YAG laser are capable of decreasing microleakage of composite resin restorations in primary teeth, and the efficiency is similar to etched bur cavities.

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

    Directory of Open Access Journals (Sweden)

    E. Yarmohammadi

    2014-10-01

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

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

    International Nuclear Information System (INIS)

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

  5. 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.

  6. 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.

  7. Atraumatic Restoration of Vertical Food Impaction with an Open Contact Using Flowable Composite Resin Aided by Cerclage Wire under Tension

    Science.gov (United States)

    Ying Cao, Chris; Xu, Qiang-Jian; Xu, Xiao-Hua; Yin, Jia-Li

    2016-01-01

    To date, treating vertical food impaction with open contact effectively, especially with an atraumatic therapy, remains a challenge. In this study, we developed a simple, atraumatic, and economic therapeutic measure to treat vertical food impaction. The scientific rationale of our therapeutic technique is to restore an intact and firm proximal contact with proper location and form relationships to prevent forceful interproximal wedging of food, which in turn protects interdental papilla. We performed the procedure using flowable composite resin or composite resin cement with the aid of a cerclage wire under tension to rebuild the contact area. The reported method is especially useful for some challenging clinical cases, such as food impaction after crown and inlay on onlay restoration, and some conventional treatment methods, such as contouring the marginal ridge and developmental grooves, are ineffective. PMID:27579217

  8. Atraumatic Restoration of Vertical Food Impaction with an Open Contact Using Flowable Composite Resin Aided by Cerclage Wire under Tension

    Directory of Open Access Journals (Sweden)

    Quan-Li Li

    2016-01-01

    Full Text Available To date, treating vertical food impaction with open contact effectively, especially with an atraumatic therapy, remains a challenge. In this study, we developed a simple, atraumatic, and economic therapeutic measure to treat vertical food impaction. The scientific rationale of our therapeutic technique is to restore an intact and firm proximal contact with proper location and form relationships to prevent forceful interproximal wedging of food, which in turn protects interdental papilla. We performed the procedure using flowable composite resin or composite resin cement with the aid of a cerclage wire under tension to rebuild the contact area. The reported method is especially useful for some challenging clinical cases, such as food impaction after crown and inlay on onlay restoration, and some conventional treatment methods, such as contouring the marginal ridge and developmental grooves, are ineffective.

  9. Clinical Effect of Dental Adhesive on Marginal Integrity in Class I And Class II Resin-Composite Restorations

    OpenAIRE

    Manchorova-Veleva Neshka A.; Vladimirov Stoyan B.; Keskinova Donka А.

    2016-01-01

    BACKGROUND: Dental adhesives are believed to influence marginal adaptation and marginal discoloration when used under posterior resin-based composite restorations. Studies on the latest adhesive systems reveal that the group of the three-step etch-and-rinse adhesive (3-E&RA) and the one-step self-etch adhesive (1-SEA) have entirely different bonding mechanisms, as well as different bond strength and resistance to chemical, thermal and mechanical factors. STUDY OBJECTIVES: A hypothesis that a ...

  10. Mirror Lake Fish catch composition - Lower Columbia River Restoration Action Effectiveness Monitoring

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 1) The purpose of this project is to measure changes in juvenile salmon habitat occurrence and health following restoration activities at the Mirror Lake Complex...

  11. Repair of amalgam restorations with composite resin and bonded amalgam: A microleakage study

    Directory of Open Access Journals (Sweden)

    Daniela Araújo Veloso Popoff

    2011-01-01

    Conclusions: The use of adhesive systems significantly affected the ability to seal the repair/ tooth interface. However, at the level of the repair/restoration interface, the bonded amalgam technique may increase microleakage.

  12. Effect of different adhesive strategies on the post-operative sensitivity of class I composite restorations

    OpenAIRE

    SANCAKLI, Hande Sar; Yildiz, Esra; Bayrak, Isil; OZEL, Sevda

    2014-01-01

    Objective: To evaluate the post-operative sensitivity of occlusal restorations using different dentin adhesives performed by an undergraduate and a post-doctorate dentist. Materials and Methods: One hundred and eighty-eight molar occlusal restorations were placed in 39 patients (ages between 18 and 30) using 3 different kind of adhesive systems; Optibond FL (OBF), Clearfil Protect Bond (CPB), and iBond (IB) by a post-doctorate dentist or a fifth-year dental student according to the manufactur...

  13. STUDY OF THE EFFECT OF DIRECT & INDIRECT COMPOSITE RESTORATIONS ON RESISTANCE TO MAXILLARY PREMOLLAR TEATH FRACTURE TREATED BY ROOT CANAL METHOD

    Directory of Open Access Journals (Sweden)

    M MOUSAVINASAB

    2003-12-01

    Full Text Available Finding a universally approved system to restore pulpess teeth has been a goal of many of dental researches. The restorative system should have enough ability to withstand masticator forces, while preserving as much tooth structure as possible. The purpose of this study was to compare the effects of light and heat curing composite with light curing composite restoration method on fracture resistance of restored teeth. Forty healthy maxillary premolar teeth were chosen, in thirty of samples endodontic treatment performed and MOD cavities were prepared as to weaken tooth structures, the specimens were divided to 4 groups containing 10 specimens as follows. Group 1: Unprepared Group2: Restored with direct light curing composite resin. Group3: Restored with light and heat curing composite resin as inlay without cementing surface treatment. Group4: Restored with light and heat curing composite resin as inlay with cementing surface treatment. All samples were subjected to compressive load by testing machine. The mean fracture load in KGF for groups 1,2,3 and 4 were 98.96, 58.72,54.04,78.36 KGF respectively. From this study it may be concluded that the use of light and heat curing methods and cementing surface treating compared with light curing and light and heat curing method without cementing surface treating will more increase fracture resistance of endodontically treated maxillary premolars.

  14. Effect of lining with a flowable composite on internal adaptation of direct composite restorations using all-in-one adhesive systems.

    Science.gov (United States)

    Yahagi, Chika; Takagaki, Tomohiro; Sadr, Alireza; Ikeda, Masaomi; Nikaido, Toru; Tagami, Junji

    2012-01-01

    The purpose of this study was to evaluate the effect of lining with a flowable composite on internal adaptation of composite restorations using three all-in-one adhesive systems; Bond Force (BF), G-Bond Plus (GP), and OptiBond All-in-one (OP), and a two-step self-etching adhesive system; Clearfil SE Bond (SE). They were applied to each cylindrical cavity prepared on the human dentin. The cavity surface was lined with/without a flowable resin composite prior to filling with a resin composite (FL/NL). After water storage for 24 h, the specimens were sectioned and polished, and internal adaptation of the restorations was assessed using a confocal laser scanning microscopy. For SE, a perfect cavity adaptation was recognized in both FL and NL. For BF, GP and OP, cavity adaptation was material dependent in NL, whereas no gap formation was observed in FL. However, voids formation was observed at the composite-adhesive-dentin interface in every all-in-one adhesive system. PMID:22673475

  15. Evaluation of gingival microleakage of class II resin composite restorations with fiber inserts: An in vitro study

    Directory of Open Access Journals (Sweden)

    R S Basavanna

    2012-01-01

    Full Text Available Aims/Objectives: To evaluate the effect of glass and polyethylene fiber inserts and flowable composite as a liner on the microleakage of Class II composite restorations with gingival margins on root surfaces. Materials and Methods: Class II slots were prepared on both the proximal sides of thirty freshly extracted mandibular molars and were divided into six groups, according to the type of fiber insert and use of flowable composite (Filtek Z350 as a liner. Filtek P-60 (3M/ESPE posterior composite was used to restore all cavities. The specimens were thermocycled and stained with 2% Basic Fuchsin dye, and sectioned to evaluate the dye penetration under Stereomicroscope. Statistical analysis was done using Kruskalwallis test and Mann whitney U test. Results and Conclusion: This study showed that, fiber insert groups, with or without flowable liner, had reduced microleakage scores as compared to the control groups. However, statistically no significant difference was found between the groups with fiber inserts. Less microleakage was seen in Group IV (With flowable liner and without Fiber inserts as compared to Group I (Without flowable liner and Fiber inserts.

  16. Soil biochar amendment in a nature restoration area: effects on plant productivity and community composition.

    Science.gov (United States)

    van de Voorde, Tess F J; Bezemer, T Martijn; Van Groenigen, Jan Willem; Jeffery, Simon; Mommer, Liesje

    2014-07-01

    Biochar (pyrolyzed biomass) amendment to soils has been shown to have a multitude of positive effects, e.g., on crop yield, soil quality, nutrient cycling, and carbon sequestration. So far the majority of studies have focused on agricultural systems, typically with relatively low species diversity and annual cropping schemes. How biochar amendment affects plant communities in more complex and diverse ecosystems that can evolve over time is largely unknown. We investigated such effects in a field experiment at a Dutch nature restoration area. In April 2011, we set up an experiment using biochar produced from cuttings collected from a local natural grassland. The material was pyrolyzed at 400 degrees C or at 600 degrees C. After biochar or residue (non-pyrolyzed cuttings) application (10 Mg/ha), all plots, including control (0 Mg/ ha) plots, were sown with an 18-species grassland mixture. In August 2011, we determined characteristics of the developed plant community, as well as soil nutrient status. Biochar amendment did not alter total plant productivity, but it had a strong and significant effect on plant community composition. Legumes were three times as abundant and individual legume plants increased four times in biomass in plots that received biochar as compared to the control treatment. Biomass of the most abundant forb (Plantago lanceolata) was not affected by biochar addition. Available phosphorous, potassium, and pH were significantly higher in soils that received biochar than in Control soils. The rate of biological nitrogen fixation and seed germination were not altered by biochar amendment, but the total amount of biological N fixed per Trifolium pratense (red clover) plant was more than four times greater in biochar-amended soil. This study demonstrates that biochar amendment has a strong and rapid effect on plant communities and soil nutrients. Over time these changes may cascade up to other trophic groups, including above- and belowground organisms

  17. Influence of proximal box elevation on the marginal quality and fracture behavior of root-filled molars restored with CAD/CAM ceramic or composite onlays

    OpenAIRE

    Ilgenstein, Irina; Zitzmann, Nicola U.; Bühler, Julia; Wegehaupt, Florian J; Attin, Thomas; WEIGER, Roland; Krastl, Gabriel

    2015-01-01

    OBJECTIVES This study investigated the influence of proximal box elevation (PBE) with composite resin when applied to deep proximal defects in root-filled molars with mesio-occluso-distal (MOD) cavities, which were subsequently restored with computer-aided designed/computer-aided manufacturing (CAD/CAM) ceramic or composite restorations. MATERIALS AND METHOD Root canal treatment was performed on 48 human mandibular molars. Standardized MOD cavities were prepared with the distal box located...

  18. Proximal direct composite restorations and chairside CAD/CAM inlays: marginal adaptation of a two-step self-etch adhesive with and without selective enamel conditioning

    OpenAIRE

    Bortolotto Ibarra, Tissiana; Onisor, Ioana; Krejci, Ivo

    2007-01-01

    The aim of this study was to evaluate the marginal adaptation of CEREC ceramic inlays, CEREC composite inlays and direct composite restorations in unbeveled proximal slot cavities under artificial aging conditions. Two groups of each restoration type were prepared (n = 6), one group with a self-etch adhesive, the other group with H(3)PO(4) enamel etching before the self-etch adhesive application. Replicas were generated before and after long-term thermo-mechanical loading under dentinal fluid...

  19. Effects of Er, Cr:YSGG laser irradiation on external adaptation of restorations in caries-affected cavities

    International Nuclear Information System (INIS)

    This study evaluated the effect of Er,Cr:YSGG laser irradiation on the external adaptation of composite resin restorations in caries-affected cavities. Mixed class V cavity preparations were performed in 36 intact human third molars, in half of which caries was artificially induced. Both healthy and carious dentin were etched with 35% phosphoric acid (Ultradent Products Inc., South Jordan, Utah, USA), and the teeth were divided into three groups, i.e., (a) untreated etched dentin, (b) application of the Er, Cr:YSGG laser and (c) use of chlorhexidine as an adjunct in the bonding process. Restorations were fabricated with Z350 XT FiltekTM composite resin (3M ESPE) and subsequently the specimens were subjected to thermocycling to simulate artificial ageing. Quantitative analysis of external adaptation was performed by scanning electron microscopy in both healthy and affected dentin using epoxy resin replicas. It was concluded that the application of laser and chlorhexidine did not affect the percentages of marginal adaptation of class V restorations. Furthermore, thermocycling may influence adaptation values. (letter)

  20. Effect of cyclic loading on microleakage of silorane based composite compared with low shrinkage methacrylate-based composites

    Science.gov (United States)

    Kermanshah, Hamid; Yasini, Esmail; Hoseinifar, Razieh

    2016-01-01

    Background: There are many concerns regarding the marginal seal of composite restorations, especially when composite restorations are subjected to cyclic loading. The aim of this study was to evaluate the effect of cyclic loading on the microleakage of silorane based composite compared with low shrinkage methacrylate-based composites in class V cavities. Materials and Methods: In this in vitro study, class V cavities were prepared on the facial and lingual surfaces of 48 human premolars (96 cavities). The teeth were randomly divided into four groups of 12 teeth (24 cavities) each and restored as follows: Group 1 (Siloran System Adhesive + Filtek P90), Group 2 (All Bond SE + Aelite LS Posterior), Group 3 (Futurabond NR + Grandio), and Group 4 (G-Bond + Kalore-GC). All the specimens were thermocycled for 2000 cycles (5-55°C) and then half of the specimens from each group, were Load cycled. All teeth were immersed in 0.5% basic fuchsine dye, sectioned, and observed under a stereomicroscope. Data were analyzed using Wilcoxon test, Kruskal–Wallis, and Mann–Whitney U-tests. P < 0.05 was considered as significant. Results: In both unloaded and loaded groups, no statistically significant differences were observed among four composites at the occlusal margin, but a significant difference in gingival microleakage was found between Aelite and silorane. Occlusal and gingival microleakage was not affected by cyclic loading in none of the four restorative materials. Conclusion: Silorane did not provide better marginal seal than the low shrinkage methacrylate-based composites (except Aelite). In addition, cyclic loading did not affect the marginal microleakage of evaluated composite restorations. PMID:27274348

  1. Soil disturbance as a grassland restoration measure-effects on plant species composition and plant functional traits.

    Directory of Open Access Journals (Sweden)

    Tim Schnoor

    Full Text Available Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success of particular species will not inform on how plant communities respond ecologically to disturbance. We therefore evaluated vegetation development following disturbance by quantifying species richness, species composition and functional trait composition. Degraded calcareous sandy grassland was subjected to experimental disturbance treatments (ploughing or rotavation, and the vegetation was surveyed during four subsequent years of succession. Treated plots were compared with control plots representing untreated grassland, as well as nearby plots characterized by plant communities representing the restoration target. Species richness and functional diversity both increased in response to soil disturbance, and rotavation, but not ploughing, had a persistent positive effect on the occurrence of specialist species of calcareous sandy grassland. However, no type of soil disturbance caused the plant species composition to develop towards the target vegetation. The disturbance had an immediate and large impact on the vegetation, but the vegetation developed rapidly back towards the control sites. Plant functional composition analysis indicated that the treatments created habitats different both from control sites and target sites. Community-weighted mean Ellenberg indicator values suggested that the observed plant community response was at least partially due to an increase in nitrogen and water availability following disturbance. This study shows that a mild type of disturbance, such as rotavation, may be most successful in promoting specialist species in calcareous sandy grassland, but that further treatments are needed to reduce nutrient availability. We

  2. Soil disturbance as a grassland restoration measure-effects on plant species composition and plant functional traits.

    Science.gov (United States)

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success of particular species will not inform on how plant communities respond ecologically to disturbance. We therefore evaluated vegetation development following disturbance by quantifying species richness, species composition and functional trait composition. Degraded calcareous sandy grassland was subjected to experimental disturbance treatments (ploughing or rotavation), and the vegetation was surveyed during four subsequent years of succession. Treated plots were compared with control plots representing untreated grassland, as well as nearby plots characterized by plant communities representing the restoration target. Species richness and functional diversity both increased in response to soil disturbance, and rotavation, but not ploughing, had a persistent positive effect on the occurrence of specialist species of calcareous sandy grassland. However, no type of soil disturbance caused the plant species composition to develop towards the target vegetation. The disturbance had an immediate and large impact on the vegetation, but the vegetation developed rapidly back towards the control sites. Plant functional composition analysis indicated that the treatments created habitats different both from control sites and target sites. Community-weighted mean Ellenberg indicator values suggested that the observed plant community response was at least partially due to an increase in nitrogen and water availability following disturbance. This study shows that a mild type of disturbance, such as rotavation, may be most successful in promoting specialist species in calcareous sandy grassland, but that further treatments are needed to reduce nutrient availability. We conclude that a

  3. Bacterial microleakage of aged adhesive restorations

    Directory of Open Access Journals (Sweden)

    Nevin Cobanoglu

    2015-01-01

    Full Text Available Objective: The aim of this study was to investigate the marginal bacterial leakage of two self-etch adhesive systems after long-term water storage. Materials and Methods: Class V cavities were prepared on the buccal and lingual surfaces of extracted premolar teeth. After the sterilization of the teeth, four cavities were not restored for control purposes, whereas the other teeth were divided into two groups (n = 16 cavities each: Clearfil Protect Bond (CPB, Clearfil SE Bond (CSE. After the application of the bonding agent, cavities were restored with a composite resin. Then, the teeth were thermo cycled, stored in saline solution for 6 months and put into a broth culture of Streptococcus mutans. The teeth were fixed, sectioned and stained using the Gram-Colour modified method. The stained sections were then evaluated under a light microscope. The bacterial leakage was scored as: 0 - absence of stained bacteria, 1 - bacterial staining along the cavity walls, 2 - bacterial staining within the cut dentinal tubules. The data were analysed using the Kruskal-Wallis and Mann-Whitney U-test (P = 0.05. Results: The bacterial staining was detected within the cut dentinal tubules in all control cavities, in three cavities in the CSE group and one cavity in the CPB group. There were no observed statistically significant differences between the bacterial penetrations of the two bonding systems (P > 0.05. Conclusion: Both bonding systems provided acceptable prevention of marginal bacterial leakage after long-term water storage.

  4. Influence of volumetric shrinkage and curing light intensity on proximal contact tightness of class II resin composite restorations: in vitro study.

    NARCIS (Netherlands)

    El-Shamy, H.; Saber, M.H.; Dorfer, C.E.; El-Badrawy, W.; Loomans, B.A.C.

    2012-01-01

    BACKGROUND : Proximal contact tightness of class II resin composite restorations is influenced by a myriad of factors. Previous studies investigated the role of matrix band type and thickness, consistency of resin composite, and technique of placement. However, the effect of volumetric shrinkage of

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

    Directory of Open Access Journals (Sweden)

    Laiza Tatiana Poskus

    2009-12-01

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

  6. Evaluation of the endodontic treatment influence on the bond strength of fiber posts reinforced by a restorative composite

    Directory of Open Access Journals (Sweden)

    Ricardo Ferreira

    2011-04-01

    Full Text Available Introduction and objective: Fiber posts are widely used to increase the mechanical strength of the restorations. The aim of this study was to evaluate the bond strength of fiber posts reinforced by a restorative composite to radicular dentin on its cervical, middle and apical thirds, regarding to post preparation prior or posterior to the endodontic treatment. Materials and methods: Thirty bovine incisors were used, which had their debris removed, washed in tap water, and stored frozen. The samples were divided into two groups (n = 15 – according to the treatment applied previously to the installation of the posts: Group 1 – root canal obturation followed by root canal preparation for fiber posts bonding; and Group 2 – fiber posts preparation followed by root canal obturation. The posts were cemented and the roots were cut on their cervical (C, medium (M and apical (A thirds – for push out test application. Bond strength was calculated in MPa and data were statistically analyzed by Anova and Tukey test (p < 0.05. Results: The mean values were (MPa ± SD: G1C – 4.0 ± 6.0; G1M – 3.5 ± 2.9; G1A – 7.2 ± 6.3; G2C – 12.7 ± 8.1; G2M – 11.6 ± 10.2; G2A – 6.5 ± 8.1. The cervical and middle thirds of group 2 had the highest mean values, showing significant statistically difference compared to group 1. For apical third, no significant statistically differences were found among groups. When the cervical, middle and apical thirds were analysed separately, no significant statistically differences were found. Conclusion: The post preparation prior to root canal obturation increased the bond strength of fiber posts reinforced by a restorative composite.

  7. Influence of post and resin cement on stress distribution of maxillary central incisors restored with direct resin composite.

    Science.gov (United States)

    Spazzin, A O; Galafassi, D; de Meira-Júnior, A D; Braz, R; Garbin, C A

    2009-01-01

    The current study evaluated the influence of two endodontic post systems and the elastic modulus and film thickness of resin cement on stress distribution in a maxillary central incisor (MCI) restored with direct resin composite using finite element analysis (FEA). A three-dimensional model of an MCI with a coronary fracture and supporting structures was performed. A static chewing pressure of 2.16 N/mm2 was applied to two areas on the palatal surface of the composite restoration. Zirconia ceramic (ZC) and glass fiber (GF) posts were considered. The stress distribution was analyzed in the post, dentin and cement layer when ZC and GF posts were fixed to the root canals using resin cements of different elastic moduli (7.0 and 18.6 GPa) and different layer thicknesses (70 and 200 microm). The different post materials presented a significant influence on stress distribution with lesser stress concentration when using the GF post. The higher elastic modulus cement created higher stress levels within itself. The cement thicknesses did not present significant changes. PMID:19363979

  8. Enhancement of mechanical properties of experimental composite by Fuller's earth nanofibers for cervical restoration.

    Science.gov (United States)

    Houshyar, Aydin; Khavandi, Ali Reza; Javadpour, Jafar; Samani, Saeed; Naimi-Jamal, Mohammad Reza; Atai, Mohammad

    2013-08-01

    In this research, we studied improvement of mechanical properties of dimethacrylate-silica based dental composites by addition of Fuller's Earth (FE) clay. Three composites were made as base compounds consisting of 68, 58, and 48 wt % resin and 31, 41, and 51 wt % silica, respectively. Afterward, the composites were modified by adding FE. Mechanical properties including flexural strength, flexural modulus, work-of-fracture, fracture toughness, and microhardness were measured. Clay particles and fracture surface of composites consisting of 51 wt % silica (with and without FE) were examined by SEM. Measured results showed that flexural strength, work-of-fracture, flexural modulus, and microhardness of all composites increased by including FE nanofibers. Fracture toughness except for composite including 51 wt % silica had similar variations. It seems that locating FE nanofibers in weak resin region among silica particles leads to strengthening mechanisms, such as bridging and crack deflection, which cause improvement in mechanical properties. PMID:23401393

  9. Clinical dental application of Er:YAG laser for Class V cavity preparation.

    Science.gov (United States)

    Matsumoto, K; Nakamura, Y; Mazeki, K; Kimura, Y

    1996-06-01

    Following the development of the ruby laser by Maiman in 1960, the Nd:YAG laser, the CO2 laser, the semiconductor laser, the He-Ne laser, excimer lasers, the argon laser, and finally the Er:YAG laser capable of cutting hard tissue easily were developed and have come to be applied clinically. In the present study, the Er:YAG laser emitting at a wavelength of 2.94 microns developed by Luxar was used for the clinical preparation of class V cavities. Parameters of 8 Hz and approx. 250 mJ/pulse maximum output were used for irradiation. Sixty teeth of 40 patients were used in this clinical study. The Er:YAG laser used in this study was found to be a system suitable for clinical application. No adverse reaction was observed in any of the cases. Class V cavity preparation was performed without inducing any pain in 48/60 cases (80%). All of the 12 cases that complained of mild or severe intraoperative pain had previously complained of cervical dentin hypersensibility during the preoperative examination. Cavity preparation was completed with this laser system in 58/60 cases (91.7%). No treatment-related clinical problems were observed during the follow-up period of approx. 30 days after cavity preparation and resin filling. Cavity preparation took between approx. 10 sec and 3 min and was related more or less to cavity size and depth. Overall clinical evaluation showed no safety problem with very good rating in 49 cases (81.7%). PMID:9484088

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

    NARCIS (Netherlands)

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

    2014-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  12. Fracture Strength of Endodontically-treated Teeth Restored with Post and Cores and Composite Cores Only

    NARCIS (Netherlands)

    Ozcan, M.; Valandro, L. F.

    2009-01-01

    This study compared the fracture strength of different conditioned metallic posts, fiber-reinforced-composite posts and composite cores only in teeth without coronal tooth structure and determined failure modes after the fracture test. Post spaces were prepared in the root canals, and the teeth were

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

    Science.gov (United States)

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

    1993-12-01

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

  14. Effect of Extension and Type of Composite-Restored Class II Cavities on Biomechanical Properties of Teeth: A Three Dimensional Finite Element Analysis

    OpenAIRE

    Azam Valian; Elham Moravej-Salehi; Allahyar Geramy; Elham Faramarzi

    2015-01-01

    Objectives: Controversy exists regarding cavity preparation for restoration of interproximal caries in posterior teeth in terms of preserving the tooth structure and suitable stress distribution. This study aimed to assess the effect of extension and type of class II cavities and the remaining tooth structure in maxillary premolars restored with composite resin on the biomechanical properties of teeth using finite element method (FEM). Materials and Methods: Using FEM, eight three-dimensional...

  15. Microleakage of composite resin restoration in cavities prepared by Er,Cr:YSGG laser irradiation and etched bur cavities in primary teeth.

    Science.gov (United States)

    Hossain, Mozammal; Nakamura, Yukio; Yamada, Yoshishige; Murakami, Yoshiko; Matsumoto, Koukichi

    2002-01-01

    In this in vitro study, the surface alterations of enamel and dentin in cavities prepared by Er,Cr:YSGG laser irradiation was investigated by scanning electron microscopy and compared to the microleakage degree after composite resin restoration with etched bur cavities in human primary teeth. The results confirmed that laser cavity surface facilitated a good adhesion with the restorative materials; the acid etch step can be easily avoided with the laser treatment.

  16. Marginal microleakage of resin-modified glass-ionomer and composite resin restorations: Effect of using etch-and-rinse and self-etch adhesives

    OpenAIRE

    Maryam Khoroushi; Tayebeh Mansouri Karvandi; Bentolhoda Kamali; Hamid Mazaheri

    2012-01-01

    Objectives: Previous studies have shown that dental adhesives increase the bond strength of resin-modified glass-ionomer (RMGI) restorative materials to dentin. This in vitro study has evaluated the effect of etch-and-rinse and self-etch bonding systems v/s cavity conditioner, and in comparison to similar composite resin restorations on maintaining the marginal sealing of RMGI restorations. Materials and Methods: 98 rectangular cavities (2.5×3×1.5 mm) were prepared on buccal and palatal a...

  17. Role of bonding agents in the repair of composite resin restorations.

    Science.gov (United States)

    Staxrud, Frode; Dahl, Jon E

    2011-08-01

    Six commonly used composite resin materials and recommended bonding systems were tested to assess shear bond strength at the interface between aged and new composites with and without bonding. Test specimens were aged in water for 60 d before new composite was placed. Shear bond strength was assessed after 22 ± 2 h (Test 1) and after additional ageing by thermocycling (5-55°C/5,000 cycles) (Test 2). After an additional 180 d in water, the aged specimens were randomly divided into three groups to blind the test with respect to the aged composite. New composites were placed on aged specimens (two groups with and one without bonding agent) and thermocycled (Test 3). After 24 h (Test 1), the mean shear bond strength of the test specimens was 21-26 MPa when bonding agents were used, as opposed to 10-15 MPa without bonding agents. After thermocycling (Test 2), the mean shear bond strength was 16-23 MPa with a bonding agent and 17 MPa without a bonding agent. After 180 d in water and subsequent thermocycling (Test 3), the mean shear bond strength was 9-13 MPa with bonding agent and 2-3 MPa when no bonding agent was used. The results of this study therefore indicate that the use of bonding agents significantly improves the quality of composite repair.

  18. Effect of chemical degradation followed by toothbrushing on the surface roughness of restorative composites

    Directory of Open Access Journals (Sweden)

    Fernanda Regina Voltarelli

    2010-12-01

    Full Text Available OBJECTIVES: The aim of the present study was to assess the effect of the exposure to food-simulating liquids prior to brushing simulation on the surface roughness of five composite materials (Quixfil, Filtek Supreme, Esthet-X, Filtek Z250, Tetric Ceram. Material and METHODS: Twenty cylinders (5 mm diameter and 4 mm height of each composite were randomly allocated to 4 groups (n=5, according to the food-simulating liquid in which they were immersed for 7 days at 37°C: artificial saliva, heptane, citric acid, and ethanol. After this period, the top surface of composite cylinders was submitted to 7,500 brushing cycles (200 g load. Measurements of the surface roughness (Ra, ¼m were carried out before and after the exposure to the chemicals/brushing simulation. Changes on the morphology of composite surfaces were observed through scanning electron microscopy (SEM. RESULTS: The statistical analysis (ANOVA with cofactor / Tukey's test, α=5% detected a significant interaction between solutions and composite resins. Esthet-X, Filtek Z250 and Tetric Ceram were not affected by the food-simulating liquids/toothbrushing. Citric acid and ethanol increased the surface roughness of Quixfil and Filtek Supreme, respectively. SEM images corroborate the surface roughness findings, demonstrating the negative effect from chemical solutions and mechanical abrasion. CONCLUSIONS: The surface roughness of composite resin materials are differently affected by the food-simulating solutions, depending on the immersion media.

  19. An In-vitro Evaluation of Effects of Light and Light-Heat Curing Inlay Composite Restorations on Fracture Resistance of Pulpless Maxillary Premolars

    Directory of Open Access Journals (Sweden)

    M. Mousavinasab

    2004-09-01

    Full Text Available Statement of Problem: The restoration of the teeth should have enough ability to withstand masticator forces while preserving as much tooth structure as possible.Purpose: The purpose of this study was to compare the effects of light-heat cured composite with light cured composite restorations on fracture resistance of the restored teeth.Materials and Methods: Forty healthy maxillary premolar teeth were chosen, endodontic treatment performed in 30 of them. MOD cavities were prepared in all of them to weaken tooth structures. Then, they were divided into 3 groups each of which contains 10 specimens. The groups were as follows:Group 1: unprepared teeth (sound teeth acted as controlGroup 2: restored teeth with direct light cured composite resin.Group 3: restored teeth with light-heat cured composite resin as inlay without any cementing surface treatmentGroup 4: restored teeth with light-heat cured composite resin inlays with cementing surface treatment.Finally all samples were subjected to compressive load by testing machine. The data were analyzed using ANOVA and Duncan tests.Results: There was a significant difference in fracture resistance between 4 groups (P<0.001 except groups 2 and 3. The mean fracture load for groups 1,2,3 and 4 were 98.96±16.05, 58.72±15.33, 54.04±15.56 and 78.36±9.83 kgf respectively.Conclusion: Using light-heat curing method and cementing surface treating of composite resin will increase fracture resistance of endodontically treated maxillary premolars.

  20. Marginal microleakage of resin-modified glass-ionomer and composite resin restorations: Effect of using etch-and-rinse and self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2012-01-01

    Full Text Available Objectives: Previous studies have shown that dental adhesives increase the bond strength of resin-modified glass-ionomer (RMGI restorative materials to dentin. This in vitro study has evaluated the effect of etch-and-rinse and self-etch bonding systems v/s cavity conditioner, and in comparison to similar composite resin restorations on maintaining the marginal sealing of RMGI restorations. Materials and Methods: 98 rectangular cavities (2.5×3×1.5 mm were prepared on buccal and palatal aspects of 49 human maxillary premolars, randomly divided into 7 groups (N=14. The cavities in groups 1, 2 and 3 were restored using a composite resin (APX. The cavities in groups 4, 5, 6 and 7 were restored using a resin-modified glass-ionomer (Fuji II LC. Before restoring, adhesive systems (Optibond FL = OFL, three-step etch-and-rinse; One Step Plus = OSP, two-step etch-and-rinse; Clearfil Protect Bond = CPB, two-step self-etch were used as bonding agents in groups 1-6 as follow: OFL in groups 1 and 4, OSP in groups 2 and 5, and CPB in groups 3 and 6, respectively. The specimens in group 7 were restored with GC cavity conditioner and Fuji II LC. All the specimens were thermo-cycled for 1000 cycles. Microleakage scores were determined using dye penetration method. Statistical analyzes were carried out with Kruskal-Wallis and Mann-Whitney U tests (α=0.05. Results: There were significant differences in microleakage scores at both enamel and dentinal margins between the study groups (P<0.05. The lowest microleakage scores at enamel and dentin margins of RMGI restorations were observed in group 6. Conclusion: Use of two-step self-etch adhesive, prior to restoring cervical cavities with RMGIC, seems to be more efficacious than the conventional cavity conditioner in decreasing marginal microleakage.

  1. Report to Congress: Class V injection wells - current inventory; effects on ground water; technical recommendations. Final report

    International Nuclear Information System (INIS)

    The report to Congress, summarizes the results of State surveys concerning Class V injection wells as defined by the 1986 Amendments to the Safe Drinking Water Act. In accordance with the Act, the report (1) identifies the categories and corresponding inventories of Class V wells in the United States and its Territories and Possessions, (2) describes primary contamination problems associated with different categories of these wells, and (3) summarizes recommendations for minimum design, construction, installation, and siting requirements that could be applied to protect underground sources of drinking water (USDW) from such contamination wherever necessary including corrective action and remedial action recommendations

  2. The effect of long-term storage on the microleakage of composite resin restorations: qualitative and quantitative evaluation

    Directory of Open Access Journals (Sweden)

    Sadek Fernanda Tranchesi

    2003-01-01

    Full Text Available The aim of this study was to evaluate the influence of storage periods of 24 hours and 3 months on the microleakage of class II cavities. Two methods of assessing microleakage were also compared. Class II cavities were prepared in sound human molars. MO cavities were restored using ABF experimental (Kuraray Medical Inc. + Z250 composite resin (3M ESPE, and DO cavities were restored using Single Bond (3M ESPE + Z250. After different storage periods, specimens were thermocycled, immersed in a dye (0.5% methylene blue solution for 4 h and longitudinally sectioned. Dye penetration was scored according to a 0-4 scale. The extent of microleakage was measured using the ImageLab 2000 program. A statistically significant correlation was verified between both evaluation methods (r = 0.978, p < 0.001. ANOVA revealed a statistically significant difference between the tested adhesive systems regarding microleakage (p < 0.001, although it was not influenced by the different storage periods.

  3. Global Ecosystem Restoration Index

    DEFF Research Database (Denmark)

    Fernandez, Miguel; Garcia, Monica; Fernandez, Nestor

    2015-01-01

    The Global ecosystem restoration index (GERI) is a composite index that integrates structural and functional aspects of the ecosystem restoration process. These elements are evaluated through a window that looks into a baseline for degraded ecosystems with the objective to assess restoration...

  4. The Nanomechanical and Tribological Properties of Restorative Dental Composites after Exposure in Different Types of Media

    Directory of Open Access Journals (Sweden)

    Hong-Yi Fan

    2014-01-01

    Full Text Available The aim of this study was to evaluate the effects of various acidic solutions on the surface mechanical properties of commercial resin composites with different microstructures (Filtek Z350 XT, TPH3, Durafill, and Superlux. Specimens were immersed in orange juice, cola, and distilled water for 5 days and the nanohardness, elastic modulus, and wear behavior of the samples were determined via the nanoindentation test and a reciprocating nanoscratch test. The nanoscratch morphology was observed using scanning electron microscopy (SEM and the wear depth was recorded by scanning probe microscopy (SPM. The results indicate that the nanofilled resin composites had the greatest hardest and highest elastic modulus, whereas the microfilled composites exhibited the lowest nanohardness and elastic modulus values. SEM observations showed that all resin composites underwent erosion and surface degradation after immersion in acidic solutions. Furthermore, the wear resistance was influenced by the composition of the acidic solution and was correlated with the nanohardness and elastic modulus. The dominant wear mechanism changed from plastic deformation to delamination after immersion in acidic solutions.

  5. A prospective 8-year follow-up of posterior resin composite restorations in permanent teeth of children and adolescents in Public Dental Health Service: reasons for replacement

    DEFF Research Database (Denmark)

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

    2014-01-01

    Objectives: the aim of the study was to investigate reasons for replacement and repair of posterior resin composite (RC) restorations placed in permanent teeth of children and adolescents attending Public Dental Health Service in Denmark. Material and method: all posterior RC placed consecutively...... in general practice showed a good durability with annual failure rates of 2 %. The main reason for failure was secondary caries followed by post-operative sensitivity and resin composite fracture. A high proportion of replaced/repaired RC restorations were caused by primary caries in a non-filled surface...

  6. Effect of Acidulated Phosphate Fluoride (APF on the Mcroleakage of Composite Flow and Fssure Sealant Restorations

    Directory of Open Access Journals (Sweden)

    Arash Poorsattar Bejeh Mir

    2012-09-01

    Full Text Available Background and Aims: A large number of investigations have revealed that physical and chemical alterations and weight loss could occur in composite materials exposed to acidic phosphate fluoride (APF gel. The purpose of this study was to assess the microleakage of a fissure sealant and a flow composite exposed to acidulated phosphate fluoride (APF gel. Materials and Methods: In this in vitro study, 60 intact human extracted premolar teeth were used. After preparing the occlusal groove, the teeth were divided into two groups (n=30. Teeth were filled with either Helioseal fissure sealant (Vivadent, Germany or Tetric flow composite (Vivadent, Germany. After that, each group was divided into two subgroups (n=15: 1.23% APF gel (Sultan, U.S.A was applied in the case subgroups, while control subgroups were preserved in normal saline solution. All of teeth were covered with 2 layers of nail varnish except for the filling zone and 1mm around the border of filling. After submerging in 0.5% fushin solution, specimens were sectioned bucco-lingually. Then dye penetration through the filling and fissure sealant was assessed by means of a stereo-microscope. The depth of dye penetration was scored. The data were analyzed using One-way ANOVA and Levene test. Results: The mean values of dye penetration were 1.26±1.09, 1.4±1.05, 1.2±1.37, and 1.4±1.35 for fissure sealant+gel, composite+gel, composite+normal saline, and normal saline groups, respectively. No significant difference was found in inter-groups (P=0.96. Conclusion: Considering the result of the present research, APF gel had no significant effect on the microleakage of Tetric flow composite filling and Helioseal fissure sealant and thus, it can be applied for routine usage.

  7. 流动树脂衬垫对树脂充填二类洞临床效果影响%Effects of intermediate layer of flowable resin composite on Class Ⅱ hybrid resin composite restorations

    Institute of Scientific and Technical Information of China (English)

    孙岩

    2013-01-01

    Objective To evaluate the performance of a hybrid resin composite in Class Ⅱ restorations with and without intermediate layer of flowable resin composite.Methods 65 participants received at least two Class Ⅱ restorations of the hybrid resin composite.One resin composite restoration of each pair was chosen at random to be restored without an intermediary layer (group A) (n =65).The other was restored with an intermediary layer with flowable resin composite (group B) (n =65).The restorations were evaluated using slightly modified USPHS criteria during 6 months,1 year and 2 years.Results Three drop outs were registered during the 2-year follow up.Five restorations were not acceptable in clinical,3 in group A and 2 in group B.The failure rate after 2 years was 4.8% (3/62) for group A,3.2% (2/62) for group B.No statistical difference was seen between restorations restored with and without flowable layer.Conclusion The hybrid resin composite shows a good clinical performance in Class Ⅱ restorations.The use of flowable resin composite as an intermediate layer does not result in improved effectiveness of the Class Ⅱ restoration.%目的 探讨流动树脂衬垫在树脂充填后牙二类洞中的作用.方法 选择65例口内同时存在两颗后牙需要二类洞修复的患者,采用自身对照研究,分为A、B两组各65例修复体,A组直接树脂充填,B组流动树脂对邻面龈壁进行洞衬后再树脂充填.6个月、1年、2年进行临床随访.结果 2年随访每组各有3名患者失访;5例修复体失败(A组3例,B组2例),失败率A组为4.8%(3/62),B组为3.2%(2/62),两组的临床效果比较差异无统计学意义(P>0.05).结论 复合树脂修复后牙二类洞可以取得满意的临床效果,流动树脂进行邻面龈壁的洞衬没有明显提高修复效果.

  8. Analysis of composites for restorative dentistry by PIXE, XRF and ERDA

    International Nuclear Information System (INIS)

    Composites used in dentistry bring into the organism elements that may induce adverse biological effects. We applied 3 MeV proton particle-induced X-ray emission (PIXE) and photon-excited X-ray fluorescence (XRF) in the qualitative analysis of 10 dental composites and we tested copper-beam elastic recoil detection analysis (ERDA) on one material. PIXE, and partly XRF, evidenced Si, K, Ca, Ti, V, Cr, Fe, Mn, Ni, Cu, Zn, Sr, Ag, Zr, Cd, In, Ba, Yb, Y, Ho, Hf and Pb, many of them at trace levels, while ERDA detected H, B, C, N, O, F, Na, Al and Si

  9. Shifts in species composition constrain restoration of overgrazed grassland using nitrogen fertilization in Inner Mongolian steppe, China.

    Directory of Open Access Journals (Sweden)

    Qing Chen

    Full Text Available Long-term livestock over-grazing causes nitrogen outputs to exceed inputs in Inner Mongolia, suggesting that low levels of nitrogen fertilization could help restore grasslands degraded by overgrazing. However, the effectiveness of such an approach depends on the response of production and species composition to the interactive drivers of nitrogen and water availability. We conducted a five-year experiment manipulating precipitation (NP: natural precipitation and SWP: simulated wet year precipitation and nitrogen (0, 25 and 50 kg N ha(-1 yr(-1 addition in Inner Mongolia. We hypothesized that nitrogen fertilization would increase forage production when water availability was relatively high. However, the extent to which nitrogen would co-limit production under average or below average rainfall in these grasslands was unknown.Aboveground net primary production (ANPP increased in response to nitrogen when precipitation was similar to or higher than the long-term average, but not when precipitation was below average. This shift in limitation was also reflected by water and nitrogen use efficiency. Belowground live biomass significantly increased with increasing water availability, but was not affected by nitrogen addition. Under natural precipitation (NP treatment, the inter-annual variation of ANPP was 3-fold greater than with stable water availability (CV(ANPP = 61±6% and 17±3% for NP and SWP treatment, respectively and nitrogen addition increased CV(ANPP even more (89±14%. This occurred in part because fertilizer nitrogen left in the soil in dry years remained available for uptake during wet years and because of high production by unpalatable annual species in wet years in the NP treatment. In summary, plant growth by residual fertilizer nitrogen could lead to sufficient yields to offset lack of additional production in dry years. However, the utility of fertilization for restoration may be constrained by shifts in species composition and

  10. Influence of immediate dentin sealing techniques on cuspal deflection and fracture resistance of teeth restored with composite resin inlays.

    Science.gov (United States)

    Oliveira, L; Mota, E G; Borges, G A; Burnett, L H; Spohr, A M

    2014-01-01

    SUMMARY This research evaluated the influence of immediate dentin sealing (IDS) techniques on cuspal deflection and fracture resistance of teeth restored with composite resin inlays. Forty-eight maxillary premolars were divided into four groups: G1, sound teeth (control); G2, without IDS; G3, IDS with Clearfil SE Bond (CSE); and G4, IDS with CSE and Protect Liner F. The teeth from groups 2, 3, and 4 received mesio-distal-occlusal preparations. The impressions were made with vinyl polysiloxane, followed by provisional restoration and storage in water for seven days. The impressions were poured using type IV die stone, and inlays with Filtek Z250 composite resin were built over each cast. The inlays were luted with Panavia F. After storage in water for 72 hours, a 200-N load was applied on the occlusal surface using a metal sphere connected to a universal testing machine, and the cuspal deflection was measured with a micrometer. The specimens were then submitted to an axial load until failure. The following mean cuspal deflection (μm) and mean fracture resistance (N) followed by the same lowercase letter represent no statistical difference by analysis of variance and Tukey (p<0.05): cuspal deflection: G1, 3.1 ± 1.5(a); G2, 10.3 ± 4.6(b); G3, 5.5 ± 1.8(ac); and G4, 7.7 ± 5.1(bc); fracture resistance: G1, 1974 ± 708(a); G2, 1162 ± 474(b); G3, 700 ± 280(b); and G4, 810 ± 343(b). IDS with CSE allowed cuspal deflection comparable with that associated with sound teeth. The application of Protect Liner F did not contribute to a decrease in cuspal deflection. The IDS techniques did not influence the fracture resistance of teeth.

  11. Shifts in species composition constrain restoration of overgrazed grassland using nitrogen fertilization in Inner Mongolian steppe, China.

    Science.gov (United States)

    Chen, Qing; Hooper, David U; Lin, Shan

    2011-01-01

    Long-term livestock over-grazing causes nitrogen outputs to exceed inputs in Inner Mongolia, suggesting that low levels of nitrogen fertilization could help restore grasslands degraded by overgrazing. However, the effectiveness of such an approach depends on the response of production and species composition to the interactive drivers of nitrogen and water availability. We conducted a five-year experiment manipulating precipitation (NP: natural precipitation and SWP: simulated wet year precipitation) and nitrogen (0, 25 and 50 kg N ha(-1) yr(-1)) addition in Inner Mongolia. We hypothesized that nitrogen fertilization would increase forage production when water availability was relatively high. However, the extent to which nitrogen would co-limit production under average or below average rainfall in these grasslands was unknown.Aboveground net primary production (ANPP) increased in response to nitrogen when precipitation was similar to or higher than the long-term average, but not when precipitation was below average. This shift in limitation was also reflected by water and nitrogen use efficiency. Belowground live biomass significantly increased with increasing water availability, but was not affected by nitrogen addition. Under natural precipitation (NP treatment), the inter-annual variation of ANPP was 3-fold greater than with stable water availability (CV(ANPP) = 61±6% and 17±3% for NP and SWP treatment, respectively) and nitrogen addition increased CV(ANPP) even more (89±14%). This occurred in part because fertilizer nitrogen left in the soil in dry years remained available for uptake during wet years and because of high production by unpalatable annual species in wet years in the NP treatment. In summary, plant growth by residual fertilizer nitrogen could lead to sufficient yields to offset lack of additional production in dry years. However, the utility of fertilization for restoration may be constrained by shifts in species composition and the lack of

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

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2010-01-01

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

  13. A new shading concept based on natural tooth color applied to direct composite restorations

    OpenAIRE

    Dietschi, Didier; Ardu, Stefano; Krejci, Ivo

    2006-01-01

    Patient demands have prompted manufacturers to improve intrinsic optical properties of resin composites and clinicians to refine application procedures. The aim of this study is to present a shading concept based on colorimetric L*a*b* and contrast ratio data of human dentin and enamel.

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

    Science.gov (United States)

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

    2014-08-01

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

  15. INFLUENCE OF IRRADIATION EXPOSURE TIME ON THE DEPTH CURE OF RESTORATIVE RESIN COMPOSITE

    Directory of Open Access Journals (Sweden)

    Francesca Fabiano

    2014-02-01

    Full Text Available A study was conducted to evaluate the degree of conversion by the hardness measurements of a commercial resin composite. The specimens were prepared according to ISO 4049 and photo-activated for 20s – 40s – 60s with a light-emitting diodes (LEDs. To establish the optimal increment technique mono-layers 1 mm and 2 mm thick were tested. The ratio bottom-to-top was assessed for the mono-layers groups. Vickers hardness profiles were measured for mono-layer, bi-layer and tri-layer along the cross-section. The microhardness map showed difference in the mechanical characteristic of overlying resin confirmed by SEM images analysis of the fracture mechanics. Curing effectiveness of resin composite is not only dependent on the curing light unit but also from thickness of the resin composite and the duration of the exposure. The data suggest that an exposure time of 40 s or higher is required to provide composites with a homogeneous and high hardness, moreover, a 1 mm buildup multi-layering technique results in adequate curing of the bottom layer and better mechanical properties.

  16. Evaluation of the Effect of Water on Three Different Light Cured Composite Restorative Materials Stored in Water: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Basawaraj Biradar

    2012-01-01

    Full Text Available Objectives. The objective of this in vitro study was to investigate whether weight gain or loss in the three different composites occurs due to water absorption when they are stored in water. Methods. The composite restorative materials selected for this study included a microfine hybrid (Synergy and two nanofilled composite restorative materials (Ceram X and Filtek Supreme Ultra. Twenty specimens of each material were fabricated of each composite material. Group A: Filtek Supreme Ultra, Group B: Synergy, Group C: Ceram X. Then all the specimens were stored in 10 ml Distilled water containing test tubes and placed in incubator at 37°C for six weeks. The weight changes of these specimens were measured daily for the first week and later once a week for next five weeks by using an electrical analytical balance. Results. The data was analyzed by one-way analysis of variance and Student's t test. All groups showed maximum amount of water absorption in the first week than gradual decrease in the water absorption from the second to the sixth week, as compared to the first week and there is no statistically significant difference between the groups tested. Conclusion. All the composite restorative material absorbs some amount of water. The water absorption of the composite may decrease the physical and mechanical properties of the composites; hence it is necessary to consider the type of the material before starting the treatment.

  17. Effect of thermal cycling and filling technique on leakage of composite resin restorations Efeito da termociclagem e da técnica de inserção na infiltração de restaurações em resina composta

    Directory of Open Access Journals (Sweden)

    Silvia Kenshima

    2004-12-01

    Full Text Available The objective of this study was to evaluate in vitro the effect on leakage of two incremental filling techniques and two composite resins with different elastic modulus and similar polymerization shrinkage. Eighty Class V cavities (4x4x2mm were prepared in bovine incisors and were randomly restored with Z-250 (Z or Durafill VS (D + Single Bond in axial (a or oblique (o increments. The restorations were divided into two groups: Not Aged - N (4-hour-storage in water at 37ºC and Aged - A (1-week storage in water at 37ºC + 1000 x - 5º-55ºC / 1-min dwell time. The specimens were covered with 2 coats of nail varnish so that only the restoration margins were exposed to silver nitrate 50% (2h and developed under fluorescent light (8h. After they were sectioned twice in buccal-lingual direction, the four exposed surfaces were digitized (Vidcap and the silver nitrate penetration was measured (ImageLab at the incisal and gingival walls. Data were analyzed by a 3-way ANOVA (Resin, Filling Technique and Aging separately for incisal and gingival walls (alpha=0.05. Resin and Aging were statistically significant either for the incisal and the gingival walls. The microfill composite resin infiltrated more than the hybrid composite. The thermal cycling caused an overall increase in silver nitrate penetration. The filling technique affected leakage depending on the composite resin and aging regimen.O objetivo deste estudo foi avaliar o efeito de duas técnicas incrementais de inserção na infiltração de restaurações de resinas compostas com módulos de elasticidade distintos e contração de polimerização semelhante. Para isto, foram preparadas 80 cavidades Classe V (4x4x2 mm em incisivos bovinos que foram restauradas de modo aleatório com Z-250 (Z ou Durafill VS (D + Single Bond em incrementos axiais (a ou oblíquos (o. As restaurações foram divididas em dois grupos: Não Envelhecidas - N (4 h em água destilada a 37º C e Envelhecidas - E (1 semana

  18. Effects of composite restorations on nitric oxide and uric acid levels in saliva

    OpenAIRE

    Nilgun Akgul; Pinar Gul; Hamit Hakan Alp; Ahmet Kiziltunc

    2015-01-01

    Background and Aims: Dental materials that are used in dentistry should be harmless to oral tissues, and should, therefore, not contain any leachable toxic and diffusible substances capable of causing side effects. This study was intended to investigate the effects on salivary nitric oxide (NO) and uric acid (UA) levels after application of dental composite filling materials to healthy volunteers. Materials and Methods: A total of 52 individuals (32 female and 20 male) participated in the stu...

  19. Flexural strength of dental composite restoratives: comparison of biaxial and three-point bending test.

    Science.gov (United States)

    Chung, S M; Yap, A U J; Chandra, S P; Lim, C T

    2004-11-15

    This study compared two test methods used to evaluate the flexural strength of resin-based dental composites. The two test methods evaluated were the three-point bending test4 and the biaxial flexural test. Materials used in this investigation were from the same manufacturer (3M ESPE) and included microfill (A110), minifill (Z100 and Filtek Z250), polyacid modified (F2000), and flowable [Filtek Flowable (FF)] composites. Flexural strength was determined with the use of both test methods after 1 week of conditioning in water at 37 degrees C. Data were analyzed with the use of an ANOVA/Scheffe test and an independent-samples t test at significance level 0.05. Mean flexural strength (n = 7) ranged from 66.61 to 147.21 and 67.27 to 182.81 MPa for three-point bending and ball-on-three-ball biaxial test methods, respectively. In both test methods, Z100 was significantly stronger than all other composites evaluated. In the three-point bending test, flexural strength of Z250 was significantly higher than A110, F2000 and FF, and FF was significantly stronger than A110 and F2000. The biaxial test method arrived at the same conclusions except that there was no significant difference between Z250 and FF. Pearson's correlation revealed a significantly (p bending test. PMID:15386492

  20. 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.

  1. 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....

  2. Fiber-reinforced Composite Resin Prosthesis to Restore Missing Posterior Teeth: A Case Report

    Directory of Open Access Journals (Sweden)

    Pekka Vallittu

    2007-01-01

    Full Text Available A fiber-reinforced composite inlay-onlay FPD was used for a single posterior tooth replacement in a patient refusing implant for psychological reasons. The FRC-FPD was made of pre-impregnated E-glass fibers (everStick, StickTeck, Turku, Finland embedded in a resin matrix (Stick Resin, StickTeck, Turku, Finland. The unidirectional glass fibers were used to make a framework structure with high volume design placed in the pontic (edentulous region. To reproduce the morphology of natural teeth, the framework structure was then veneered with Gradia (GC, Tokyo, Japan.

  3. 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

  4. Comparison of the fracture resistance of endodontically treated teeth restored with prefabricated posts and composite resin cores with different post lenghts

    Directory of Open Access Journals (Sweden)

    Accácio Lins do Valle

    2007-02-01

    Full Text Available OBJECTIVE: This study evaluated the fracture strengths of endodontically treated teeth restored with prefabricated posts with different post lengths. MATERIAL AND METHODS: Thirty freshly extracted canines were endodontically treated. They were randomly divided into groups of 10 teeth and prepared according to 3 experimental protocols, as follows; Group 1/3 PP: teeth restored with prefabricated post and composite resin core (Z250 with post length of 5.0mm; Group 1/2 PP and Group 2/3 PP: teeth restored with prefabricated post and composite resin core (Z250 with different combinations of post length of 7.5mm and 10mm, respectively. All teeth were restored with full metal crowns. The fracture resistance (N was measured in a universal testing machine (crosshead speed 0.5mm/min at 45 degrees to the tooth long axis until failure. Data were analyzed by one-way analysis of variance (alpha=.05. RESULTS: The one-way analysis of variance demonstrated no significant difference among the different post lengths (P>.05 (Groups 1/3 PP = 405.4 N, 1/2 PP = 395.6 N, 2/3 PP = 393.8 N. Failures occurred mainly due to core fracture. CONCLUSIONS: The results of this study showed that an increased post length in teeth restored with prefabricated posts did not significantly increase the fracture resistance of endodontically treated teeth.

  5. Effect of a CO2 Laser on the Inhibition of Root Surface Caries Adjacent to Restorations of Glass Ionomer Cement or Composite Resin: An In Vitro Study.

    Science.gov (United States)

    Daniel, L C; Araújo, F C; Zancopé, B R; Hanashiro, F S; Nobre-dos-Santos, M; Youssef, M N; Souza-Zaroni, W C

    2015-01-01

    This study investigated the effect of CO2 laser irradiation on the inhibition of secondary caries on root surfaces adjacent to glass ionomer cement (GIC) or composite resin (CR) restorations. 40 dental blocks were divided into 4 groups: G1 (negative control): cavity preparation + adhesive restoration with CR; G2: (positive control) cavity preparation + GIC restoration; G3: equal to group 1 + CO2 laser with 6 J/cm(2); G4: equal to group 2 + CO2 laser. The blocks were submitted to thermal and pH cycling. Dental demineralization around restorations was quantified using microhardness analyses and Light-Induced Fluorescence (QLF). The groups showed no significant differences in mineral loss at depths between 20 μm and 40 μm. At 60 μm, G2 and G3 ≠ G1, but G4 = G1, G2 and G3. At 80 μm, G4 ≠ G1, and at 100 μm, G4 = G2 = G1. At 140 and 220 μm, G2, G3, and G4 = G1. The averages obtained using QFL in groups 1, 2, 3, and 4 were 0.637, 0.162, 0.095, and 0.048, respectively. QLF and microhardness analyses showed that CO2 laser irradiation reduced mineral loss around the CR restorations but that it did not increase the anticariogenic effect of GIC restorations. PMID:26347900

  6. Effect of a CO2 Laser on the Inhibition of Root Surface Caries Adjacent to Restorations of Glass Ionomer Cement or Composite Resin: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    L. C. Daniel

    2015-01-01

    Full Text Available This study investigated the effect of CO2 laser irradiation on the inhibition of secondary caries on root surfaces adjacent to glass ionomer cement (GIC or composite resin (CR restorations. 40 dental blocks were divided into 4 groups: G1 (negative control: cavity preparation + adhesive restoration with CR; G2: (positive control cavity preparation + GIC restoration; G3: equal to group 1 + CO2 laser with 6 J/cm2; G4: equal to group 2 + CO2 laser. The blocks were submitted to thermal and pH cycling. Dental demineralization around restorations was quantified using microhardness analyses and Light-Induced Fluorescence (QLF. The groups showed no significant differences in mineral loss at depths between 20 μm and 40 μm. At 60 μm, G2 and G3 ≠ G1, but G4 = G1, G2 and G3. At 80 μm, G4 ≠ G1, and at 100 μm, G4 = G2 = G1. At 140 and 220 μm, G2, G3, and G4 = G1. The averages obtained using QFL in groups 1, 2, 3, and 4 were 0.637, 0.162, 0.095, and 0.048, respectively. QLF and microhardness analyses showed that CO2 laser irradiation reduced mineral loss around the CR restorations but that it did not increase the anticariogenic effect of GIC restorations.

  7. Quantitative evaluation of microleakage in class V cavities using one-bottle and self-etching adhesive systems Avaliação quantitativa da microinfiltração em cavidades classe V utilizando sistemas adesivos de frasco único ou autocondicionante

    Directory of Open Access Journals (Sweden)

    Fabiana Mantovani Gomes França

    2004-09-01

    Full Text Available The aim of this in vitro study was to evaluate quantitatively the microleakage in class V cavities restored with one-bottle and self-etching adhesive systems with and without previous acid etching. Two one-bottle adhesive systems (Single Bond and Prime & Bond 2.1 and one self-etching adhesive system (Clearfil Mega Bond were used in this study. One hundred and twenty sound human premolar teeth were randomly divided into 6 groups, and 20 class V restorations were prepared in the root dentin to test each bonding system. Each bonding system was used with and without acid etching. Specimens were prepared, dyed with 2% methylene blue, sectioned, triturated, and evaluated with an absorbance spectrophotometer test in order to quantify the infiltrated dye. Results were statistically evaluated by ANOVA and Tukey-Kramer test. No statistically significant differences were found among the adhesive systems when no etching agent was used. However, the Single Bond adhesive system showed statistically significant lower microleakage means than Clearfil Mega Bond and Prime & Bond 2.1 when 37% phosphoric acid was used. Single Bond and Clearfil Mega Bond adhesive systems presented similar behavior when the manufacturers' instructions were followed.O objetivo deste estudo in vitro foi avaliar quantitativamente a microinfiltração em cavidades classe V restauradas com a utilização de sistemas adesivos de frasco único e autocondicionante com e sem a realização de condicionamento ácido prévio. Dois sistemas adesivos de frasco único, Single Bond e Prime & Bond 2.1, e um sistema adesivo autocondicionante, Clearfil Mega Bond, foram utilizados. Cento e vinte pré-molares humanos hígidos foram divididos em seis grupos, e vinte restaurações classe V foram preparadas na dentina radicular para avaliar cada sistema adesivo. Cada sistema adesivo foi utilizado com e sem condicionamento ácido. Os espécimes foram preparados, corados com azul de metileno a 2

  8. Effect of Bleaching on Color Change and Surface Topography of Composite Restorations

    Directory of Open Access Journals (Sweden)

    Gunjan Pruthi

    2010-01-01

    Full Text Available This study was conducted to determine the effect of 15% carbamide peroxide bleaching agent on color change and surface topography of different composite veneering materials (Filtek Z350 (3M ESPE, Esthet X (Dentsply India, and Admira (Voco, Germany. Methods. 30 samples were fabricated for evaluation of color change using CIELAB color system and Gonioreflectometer (GK 311/M, ZEISS. 45 disc-shaped specimens were made for evaluation of surface topography after bleaching (Nupro White Gold; Dentsply using SEM. Statistical analysis. One way ANOVA and Multiple comparison tests were used to analyze the data. Statistical significance was declared if the P value was .05 or less. Results and conclusion. All the specimens showed significant discoloration (ΔE>3.3 after their immersion in solutions representing food and beverages. The total color change after bleaching as compared to baseline color was significant in Filtek Z350 (P=.000 and Esthet X (P=.002, while it was insignificant for Admira (P=.18. Esthet X showed maximum surface roughness followed by Admira and Filtek Z350. Bleaching was effective in reducing the discoloration to a clinically acceptable value in all the three groups (ΔE<3.3.

  9. Root canal filling: fracture strength of fiber-reinforced composite-restored roots and finite element analysis.

    Science.gov (United States)

    Rippe, Marília Pivetta; Santini, Manuela Favarin; Bier, Carlos Alexandre Souza; Borges, Alexandre Luiz Souto; Valandro, Luiz Felipe

    2013-01-01

    The aims of this study were to evaluate the effect of root canal filling techniques on root fracture resistance and to analyze, by finite element analysis (FEA), the expansion of the endodontic sealer in two different root canal techniques. Thirty single-rooted human teeth were instrumented with rotary files to a standardized working length of 14 mm. The specimens were embedded in acrylic resin using plastic cylinders as molds, and allocated into 3 groups (n=10): G(lateral) - lateral condensation; G(single-cone) - single cone; G(tagger) - Tagger's hybrid technique. The root canals were prepared to a length of 11 mm with the #3 preparation bur of a tapered glass fiber-reinforced composite post system. All roots received glass fiber posts, which were adhesively cemented and a composite resin core was built. All groups were subjected to a fracture strength test (1 mm/min, 45°). Data were analyzed statistically by one-way ANOVA with a significance level of 5%. FEA was performed using two models: one simulated lateral condensation and Tagger's hybrid technique, and the other one simulated the single-cone technique. The second model was designed with an amount of gutta-percha two times smaller and a sealer layer two times thicker than the first model. The results were analyzed using von Mises stress criteria. One-way ANOVA indicated that the root canal filling technique affected the fracture strength (p=0.004). The G(lateral) and G(tagger) produced similar fracture strength values, while G(single-cone) showed the lowest values. The FEA showed that the single-cone model generated higher stress in the root canal walls. Sealer thickness seems to influence the fracture strength of restored endodontically treated teeth. PMID:24474359

  10. Root canal filling: fracture strength of fiber-reinforced composite-restored roots and finite element analysis.

    Science.gov (United States)

    Rippe, Marília Pivetta; Santini, Manuela Favarin; Bier, Carlos Alexandre Souza; Borges, Alexandre Luiz Souto; Valandro, Luiz Felipe

    2013-01-01

    The aims of this study were to evaluate the effect of root canal filling techniques on root fracture resistance and to analyze, by finite element analysis (FEA), the expansion of the endodontic sealer in two different root canal techniques. Thirty single-rooted human teeth were instrumented with rotary files to a standardized working length of 14 mm. The specimens were embedded in acrylic resin using plastic cylinders as molds, and allocated into 3 groups (n=10): G(lateral) - lateral condensation; G(single-cone) - single cone; G(tagger) - Tagger's hybrid technique. The root canals were prepared to a length of 11 mm with the #3 preparation bur of a tapered glass fiber-reinforced composite post system. All roots received glass fiber posts, which were adhesively cemented and a composite resin core was built. All groups were subjected to a fracture strength test (1 mm/min, 45°). Data were analyzed statistically by one-way ANOVA with a significance level of 5%. FEA was performed using two models: one simulated lateral condensation and Tagger's hybrid technique, and the other one simulated the single-cone technique. The second model was designed with an amount of gutta-percha two times smaller and a sealer layer two times thicker than the first model. The results were analyzed using von Mises stress criteria. One-way ANOVA indicated that the root canal filling technique affected the fracture strength (p=0.004). The G(lateral) and G(tagger) produced similar fracture strength values, while G(single-cone) showed the lowest values. The FEA showed that the single-cone model generated higher stress in the root canal walls. Sealer thickness seems to influence the fracture strength of restored endodontically treated teeth.

  11. Influence of method and period of storage on the microtensile bond strength of indirect composite resin restorations to dentine

    Directory of Open Access Journals (Sweden)

    Fernanda Ribeiro Santana

    2008-12-01

    Full Text Available This study evaluated the influence of the method and period of storage on the adhesive bond strength of indirect composite resin to bovine dentin. Ninety bovine incisors were stored in three different solutions: 0.2% thymol, 10% formalin, and 0.2% sodium azide, during 3 periods of storage: 7 days, 30 days and 6 months, resulting in 9 groups (n = 10. The roots were cut off and the buccal surface was ground with #600-grit silicon carbide paper. The surface was conditioned with 37% phosphoric acid for 15 s and a composite resin restoration (TPH Spectrum was fixed using a one-bottle adhesive system (Adper Single Bond and a dual-cured resinous cement (Rely X ARC under a load of 500 g for 5 minutes. The samples were serially cut perpendicular to the bonded interface to obtain slices of 1.2 mm in thickness. Each slab was trimmed with a cylindrical diamond bur resulting in an hourglass shape with a cross-sectional area of approximately 1 mm². The microtensile bond strength (μTBS testing was performed in a testing machine (EMIC 2000 DL at a 0.5 mm/minute crosshead-speed until failure. After fracture, the specimens were examined under SEM to analyze the mode of fracture. μTBS Means were expressed in MPa and the data were analyzed by two-way ANOVA (3X3 and the Tukey test (α = 0.05. The storage times of 7 and 30 days produced no significant difference irrespective of the solution type. The formalin and thymol solutions, however, did have a negative influence on bond strength when the teeth were stored for 6 months.

  12. Synchrotron-radiation-based X-ray micro-computed tomography reveals dental bur debris under dental composite restorations.

    Science.gov (United States)

    Hedayat, Assem; Nagy, Nicole; Packota, Garnet; Monteith, Judy; Allen, Darcy; Wysokinski, Tomasz; Zhu, Ning

    2016-05-01

    Dental burs are used extensively in dentistry to mechanically prepare tooth structures for restorations (fillings), yet little has been reported on the bur debris left behind in the teeth, and whether it poses potential health risks to patients. Here it is aimed to image dental bur debris under dental fillings, and allude to the potential health hazards that can be caused by this debris when left in direct contact with the biological surroundings, specifically when the debris is made of a non-biocompatible material. Non-destructive micro-computed tomography using the BioMedical Imaging & Therapy facility 05ID-2 beamline at the Canadian Light Source was pursued at 50 keV and at a pixel size of 4 µm to image dental bur fragments under a composite resin dental filling. The bur's cutting edges that produced the fragment were also chemically analyzed. The technique revealed dental bur fragments of different sizes in different locations on the floor of the prepared surface of the teeth and under the filling, which places them in direct contact with the dentinal tubules and the dentinal fluid circulating within them. Dispersive X-ray spectroscopy elemental analysis of the dental bur edges revealed that the fragments are made of tungsten carbide-cobalt, which is bio-incompatible.

  13. 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.

  14. Dentin Pre-Treatment to Suppress Microleakage of Amalgam Restorations

    Directory of Open Access Journals (Sweden)

    Yosi Kusuma Eriwati Arianto

    2015-10-01

    Full Text Available Diminished microleakage of amalgam-to-dentin preparations would benefit large populations in public health facilities. Prior studies demonstrated less microleakage for bonded amalgams than similarly bonded advanced composites among 30 different composite/bonding agent/storage conditions, Haller et al. showed that a combination of formaldehyde pre-treatment and glutaraldehyde-containing Syntac adhesive minimized microleakage. In the current study, CLass V restorations (groups of 10 formaldehyde-treated non carious human molars were filled with Valiant (Ivoclar NA amalgam after application of one of three liners: Copalite varnish; Amalagambond Plus with microfiber; and Syntac/Variolink. The control group used no liner material. After 24 hours at 37°C/100% RH, samples were thermocycled (1000 eyeles in water at 5°C and 60°C (15 second dwell time in each. Samples were immersed in 5% methylene blue solution (4 hrs and observed under a stereomicroscope; interfaces also were examined by SEM. Krsukal Wallis ANOVA by ranks (P<0.01 and Mann Whitney U Tests (P<0.05 of the data indicate improvements (equivalent among the 3 different liners tested here over unlined amalgam preparations. Liner/aldehyde-crosslinked dentin interphases, without technique-sensitive composites, may minimize microleakage by improving amalgam contact (physical bonding.

  15. Properties of Polymer-Composite Used as Fills of Asian Lacquerware: Issues on Restoration Processes of Lacquered Objects from Cultural Heritage

    Directory of Open Access Journals (Sweden)

    Anne-Solenn Le Hô

    2015-01-01

    Full Text Available One of the common problems encountered in lacquerware issued from cultural heritage is the appearance of lifting areas and some losses of material. Composite systems made of commercial polymer and different fills were tested as filling agents for the cracking, splitting, and losses compensation of Asian lacquer. For that purpose, the stability of traditional and modern commercially available materials usually used in the restoration practice of historical lacquerware was assessed. Their thermomechanical and chemical properties and surface state were evaluated by a set of techniques (TGA, DMA, mechanical test, contact angle value, and microtopography. There is a drastic change of the behavior of the interface between fill and Asian lacquer, dependent on the nature of the composite fillers. So the evaluation of materials and processes for the restoration of Asian lacquer were emphasized. The commercial Paraloid B72 used with glass microspheres as additives appeared to be the most stable of all of the investigated fillers.

  16. Biomechanical considerations for the restoration of endodontically treated teeth: a systematic review of the literature-Part 1. Composition and micro- and macrostructure alterations

    OpenAIRE

    Dietschi, Didier; Duc, Olivier; Krejci, Ivo; Sadan, Avishai

    2007-01-01

    The specific biomechanical alterations related to vitality loss or endodontic procedures are confusing issues for the practitioner and have been controversially approached from a clinical standpoint. The aim of part 1 of this literature review is to present an overview of the current knowledge about composition changes, structural alterations, and status following endodontic therapy and restorative procedures. The basic search process included a systematic review of the PubMed/Medline databas...

  17. 体外模型中3种光固化树脂充填体边缘微渗漏实验研究%Experiment on Gingival Marginal Microleakage of Three Kinds of Composite Restorations in Artificial Model. DONG

    Institute of Scientific and Technical Information of China (English)

    董世涛

    2011-01-01

    Objective: To evaluate the degree of marginal microleakage of three kinds of composites in vitro model.Methods: Thirty-six premolars neck cavities were randomly assigned to 3 experimerimental groups in vitro, 12 of each. Class V cavities were prepared on labial side of each tooth. Composite Valur Plus, liquid nanocomposite resin Z350 and resin composite Esthet XTM were used respectively to each group, with twelve cavities for every kind of composite. After thermal cycling(x600,4-60℃), the teeth were immersed in 1% basic fuchsin dye for 24hours at room temperature. All teeth were cut labial- lingual direction and the penetration of dye along the wall of cavities were observed under stereoscopic microscope. Results: Restorative nanoleucite composite resins Z350 is a lesser microleakage material. Significant differences were observed between nanoleucite composite resins Z350 and other two materials(P<0.01) . No statistically significant differences in microleakage were noted between other two groups.Conclusion: Liquid nanocomposite resin Z350 is a better clinical material for filling the buccal neck carity.%目的:比较3种光固化充填材料在体外模型中充填体边缘的微渗漏程度.方法:在36颗离体的前磨牙颊侧颈部备洞.随机分为3组,每组12颗牙.分别充填3M 前后牙通用树脂Valux Plus、流动性纳米复合树脂Z350、登士柏 Esthet.XTM复合树脂.样本经温度循环,采用10 g/L碱性品红染色后,颊舌向沿长轴连续切开,在体式显微镜下观察修复体与牙体洞壁间染料渗漏情况.结果:3种材料中流动性纳米复合树脂Z350微渗漏最小.前后牙通用树脂Valux Plus微渗漏最大.流动性纳米复合树脂Z350与其他两组相比有显著性差异(P<0.01).结论:流动性纳米复合树脂Z350是临床上充填颊侧颈部窝洞的较好材料.

  18. Flow regime in a restored wetland determines trophic links and species composition in the aquatic macroinvertebrate community

    Energy Technology Data Exchange (ETDEWEB)

    González-Ortegón, E., E-mail: quique.gonzalezortegon@andaluciajunta.es [School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB (United Kingdom); IFAPA Centro El Toruño, Camino Tiro de Pichón s/n, 11500 El Puerto de Santa María (Spain); Walton, M.E.M.; Moghaddam, B. [School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB (United Kingdom); Vilas, C.; Prieto, A. [IFAPA Centro El Toruño, Camino Tiro de Pichón s/n, 11500 El Puerto de Santa María (Spain); Kennedy, H.A. [School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB (United Kingdom); Pedro Cañavate, J. [IFAPA Centro El Toruño, Camino Tiro de Pichón s/n, 11500 El Puerto de Santa María (Spain); Le Vay, L. [School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB (United Kingdom)

    2015-01-15

    In a restored wetland (South of Spain), where different flow regimes control water exchange with the adjacent Guadalquivir estuary, the native Palaemon varians coexists with an exotic counterpart species Palaemon macrodactylus. This controlled m/acrocosm offers an excellent opportunity to investigate how the effects of water management, through different flow regimes, and the presence of a non-native species affect the aquatic community and the trophic niche (by gut contents and C-N isotopic composition) of the native shrimp Palaemon varians. We found that increased water exchange rate (5% day{sup −1} in mixed ponds vs. 0.1% day{sup −1} in extensive ponds) modified the aquatic community of this wetland; while extensive ponds are dominated by isopods and amphipods with low presence of P. macrodactylus, mixed ponds presented high biomass of mysids, corixids, copepods and both shrimp species. An estuarine origin of nutrients and primary production might explain seasonal and spatial differences found among ponds of this wetland. A combined analysis of gut contents and isotopic composition of the native and the exotic species showed that: (1) native P. varians is mainly omnivorous (2) while the non-native P. macrodactylus is more zooplanktivorous and (3) a dietary overlap occurred when both species coexist at mixed ponds where a higher water exchange and high abundance of mysids and copepods diversifies the native species' diet. Thus differences in the trophic ecology of both species are clearly explained by water management. This experimental study is a valuable tool for integrated management between river basin and wetlands since it allows quantification of wetland community changes in response to the flow regime. - Highlights: • Flow regimen is a major determinant of physicochemical habitat of a wetland. • Water exchanges wetland-estuary modify its aquatic community and trophic links. • Omnivory and physiological tolerance key in the resistance of a

  19. Long-term evaluation of extensive restorations in permanent teeth

    DEFF Research Database (Denmark)

    Nieuwenhuysen, J.-P. van; D'hoore, W.D.; Carvalho, J.;

    2003-01-01

    Biostatistics, cast crowns, complex restorations, composite resins, decision making, dental amalgam, metal ceramic crowns, multi-surfaced restorations, prosthodontics, restorative dentistry......Biostatistics, cast crowns, complex restorations, composite resins, decision making, dental amalgam, metal ceramic crowns, multi-surfaced restorations, prosthodontics, restorative dentistry...

  20. Eight-year randomized clinical evaluation of Class II nanohybrid resin composite restorations bonded with a one-step self-etch or a two-step etch-and-rinse adhesive

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2015-01-01

    Objectives: The aimof this study is to observe the durability of Class II nanohybrid resin composite restorations, placed with two different adhesive systems, in an 8-year follow-up. Methods: Seventy-eight participants received at random at least two Class II restorations of the ormocer-based nan...

  1. A comparative evaluation of fracture resistance of endodontically treated teeth, with variable marginal ridge thicknesses, restored with composite resin and composite resin reinforced with Ribbond: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vaishali Kalburge

    2013-01-01

    Full Text Available Background: The anatomic shape of maxillary premolars show a tendency towards separation of their cusps during mastication after endodontic treatment. Preservation of the marginal ridge of endodontically treated and restored premolars can act as a strengthening factor and improve the fracture resistance. Objectives: To evaluate the effect of varying thickness of marginal ridge on the fracture resistance of endodontically treated maxillary premolars restored with composite and Ribbond reinforced composites. Materials and Methods: One hundred and twenty, freshly extracted, non carious human mature maxillary premolars were selected for this experimental in vitro study. The teeth were randomly assigned in to twelve groups ( n = 10. Group 1 received no preparation. All the premolars in other groups were root canal treated. In subgroups of 3 and 4, DO cavities were prepared while MOD cavities were prepared for all subgroups of group 2, the dimensions of the proximal boxes were kept uniform. In group 3 and 4 the dimensions of the mesial marginal ridge were measured using a digital Vernier caliper as 2 mm, 1.5 mm, 1 mm and 0.5 mm in the respective subgroups. All samples in groups 2.2 and all the subgroups of 3 were restored with a dentin bonding agent and resin composite. The teeth in group 2.3 and all subgroups of 4 were restored with composite reinforced with Ribbond fibers. The premolars were submitted to axial compression up to failure at 45 degree angle to a palatal cusp in universal testing machine. The mean load necessary to fracture was recorded in Newtons and the data was analysed. Results: There was a highly significant difference between mean values of force required to fracture teeth in group 1 and all subgroups of group 2, 3 and 4 (i.e., P < 0.01 Conclusion: On the basis of static loading, preserving the mesial marginal ridge with thicknesses of mm, 1.5 mm, 1 mm and 0.5 mm, composite restored and Ribbond reinforced composite restored

  2. Effect of Extension and Type of Composite-Restored Class II Cavities on Biomechanical Properties of Teeth: A Three Dimensional Finite Element Analysis.

    Directory of Open Access Journals (Sweden)

    Azam Valian

    2015-04-01

    Full Text Available Controversy exists regarding cavity preparation for restoration of interproximal caries in posterior teeth in terms of preserving the tooth structure and suitable stress distribution. This study aimed to assess the effect of extension and type of class II cavities and the remaining tooth structure in maxillary premolars restored with composite resin on the biomechanical properties of teeth using finite element method (FEM.Using FEM, eight three-dimensional (3D models of class II cavities in maxillary premolars with variable mesiodistal (MD dimensions, variable thickness of the residual wall in-between the mesial and distal cavities and different locations of the wall were designed. Other dimensions were the same in all models. Cavities were restored with composite resin. A load equal to the masticatory force (200N was applied to the teeth. Finite element analysis (FEA was used to calculate the von Mises stress.Stress in the enamel margin increased by increasing the MD dimensions of the cavities. Deviation of the residual wall between the mesial and distal cavities from the tooth center was found to be an important factor in increasing stress concentration in the enamel. Increasing the MD dimensions of the cavity did not cause any increase in stress concentration in dentin.Increasing the MD dimensions of the cavities, decreasing the thickness of the residual wall between the mesial and distal cavities and its deviation from the tooth center can increase stress concentration in the enamel but not in dentin.

  3. A 13-year clinical evaluation of two three-step etch-and-rinse adhesives in non-carious class-V lesions.

    Science.gov (United States)

    Peumans, Marleen; De Munck, Jan; Van Landuyt, Kirsten L; Poitevin, Andre; Lambrechts, Paul; Van Meerbeek, Bart

    2012-02-01

    This 13-year randomized clinical trial compared the clinical effectiveness of two three-step etch-and-rinse adhesives in combination with a hybrid, stiffer composite versus a micro-filled, more flexible composite. The influence of composite stiffness on the clinical performance of one of the adhesives was assessed as well. One hundred and forty-two non-carious cervical lesions were restored with composites with contrasting stiffness. Seventy-one patients randomly received two cervical restorations placed following two out of three adhesive procedures: (1) the three-step etch-and-rinse adhesive Permaquick applied with the stiff micro-hybrid composite Amelogen Hybrid (PMQ-H, Ultradent), (2) Permaquick applied with the more flexible micro-filled Amelogen Microfill (PMQ-M, Ultradent), or (3) the "gold-standard" three-step etch-and-rinse adhesive Optibond FL applied with the micro-hybrid composite Prodigy (OFL-P, Kerr). The restorations were evaluated after 6 months, 1, 2, 3, 5, 7, and 13 years of clinical service regarding their retention, marginal integrity and discoloration, caries occurrence, preservation of tooth vitality, and post-operative sensitivity. Retention loss, severe marginal defects, and/or discoloration that needed intervention (repair or replacement) and the occurrence of caries were considered as clinical failures. The recall rate at 13 years was 77%. Bond degradation after 13 years was mainly characterized by a further increase in the presence of small but clinically acceptable marginal defects and superficial marginal discoloration. Twelve percent of the OFL-P restorations were clinically unacceptable. In the PMQ group, 22% of the PMQ-M restorations and 26% of the PMQ-H restorations needed repair or replacement. Regarding the clinical failure rate, Optibond FL scored significantly better than Permaquick (McNemar; p = 0.015). No statistically significant differences were found between the micro-filled and the hybrid composite for each of the

  4. Comparison of nanoleakage in composite restorations following application of self-etch and total-etch adhesives in primary and permanent teeth

    Directory of Open Access Journals (Sweden)

    Makarem A

    2007-01-01

    Full Text Available Background and Aim: Nanoleakage can cause discoloration around restoration margins, secondary caries, postoperative sensitivity and finally loss of restoration, thus adequate hybrid layer is of primary importance in prevention of nanoleakage in adhesive restorations. Because of structural differences between primary and permanent dentin, evaluation of nanoleakge in primary teeth is very important. The aim of this study was to evaluate the nanoleakage in composite restorations following application of self -etch and total-etch adhesives in primary and permanent teeth. Materials and Methods: In this experimental study, Cl V cavities were prepared in buccal surfaces of 20 extracted primary molars and 20 extracted premolars. Each group was divided into 2 subgroups: In group (A, Gluma One Bond and in group (B, iBond adhesive materials were applied. After silver nitrate staining, specimens were mesiodistally sectioned and polished and then SEM examination was carried out to measure the nanoleakage .Data were analyzed statistically using, ANOVA and Duncan tests with p<0.05 as the limit of significance. Results: Factors tested had no significant effect on each other. Primary teeth showed more nanoleakage than permanent teeth (P<0.05. Mean nanoleakage was significantly higher in cervical than occlusal margins (P<0.05 and also in iBond than in Gluma One Bond in primary teeth (P<0.05. In permanent teeth, the lowest nanoleakage was observed in Gluma One Bond. Conclusion: The result of this study indicates that the use of total etch dentin adhesives (Gluma One Bond in bonded restorations results in less nanoleakage in primary and permanent teeth.

  5. Eight-year randomized clinical evaluation of Class II nanohybrid resin composite restorations bonded with a one-step self-etch or a two-step etch-and-rinse adhesive

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2015-01-01

    Objectives: The aimof this study is to observe the durability of Class II nanohybrid resin composite restorations, placed with two different adhesive systems, in an 8-year follow-up. Methods: Seventy-eight participants received at random at least two Class II restorations of the ormocer......-based nanohybrid resin composite (Ceram X) bonded with either a one-step self-etch adhesive (Xeno III) or a control two-step etch-and-rinse adhesive (Excite). The 165 restorations were evaluated using slightly modified United States Public Health Services (USPHS) criteria at baseline and then yearly during 8 years...... and no significant difference in overall clinical performance between the two adhesives. Fracture was the main reason for failure. Clinical relevance: The one-step self-etch adhesive showed a good long-term clinical effectiveness in combination with the nanohybrid resin composite in Class II restorations....

  6. Evaluation of the temperature rise in pulp chamber during class V preparation with Er:YAG laser; Avaliacao da temperatura na camara pulpar durante preparo classe V com laser de Erbio:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Picinini, Leonardo Santos

    2001-07-01

    One of the major concerns regarding laser irradiation in the dentistry field is the overheating in dental tissue, specially pulpal tissue. A temperature raise over 5.5 deg C is considered to be harmful to its vitality. The current study evaluated the temperature increase in the pulp chamber, during class V preparation, performed with the laser Er:YAG in 36 bovine incisive extracted teeth. The samples were eroded on the outer side of the vestibular wall to obtain the dentinal thickness of 2.0 mm (group I), 1.0 mm (group II) and 0.5 mm (group III). Thermocouples were fixed to the inner part of the vestibular wall using thermal paste, through the palatine opening of the samples. Class V cavities were prepared in the vestibular side only in 1 mm{sup 2} thick dentins. Irradiation parameters used were: 500 mJ/10 Hz, 850 mJ/10 Hz and 1 000 mJ/10 Hz for all the groups. The results were processed by a microcomputer. This study showed that the temperature increased into the pulpal cavity reached around 3 deg C for the groups I (2,0 mm thick dentine) and II (1.0 mm thick dentine). In the group III (0.5 mm thick) temperature was around 5.5 deg C. Thus, the parameters used for cavity preparation, using Er:YAG laser, were safe in relation to the temperature raise for dentinal thickness of 1,0 and 2,0 mm; in 0.5 mm thick dentins, temperature increase reached 5.5 deg C and an appropriate correction in the laser parameters was necessary. (author)

  7. Direct Tensile Strength and Characteristics of Dentin Restored with All-Ceramic, Resin-Composite, and Cast Metal Prostheses Cemented with Resin Adhesives

    Directory of Open Access Journals (Sweden)

    Morakot Piemjai

    2015-01-01

    Full Text Available A dentin-cement-prosthesis complex restored with either all-porcelain, cured resin-composite, or cast base metal alloy and cemented with either of the different resin cements was trimmed into a mini-dumbbell shape for tensile testing. The fractured surfaces and characterization of the dentin-cement interface of bonded specimens were investigated using a Scanning Electron Microscope. A significantly higher tensile strength of all-porcelain (12.5 ± 2.2 MPa than that of cast metal (9.2 ± 3.5 MPa restorations was revealed with cohesive failure in the cement and failure at the prosthesis-cement interface in Super-Bond C&B group. No significant difference in tensile strength was found among the types of restorations using the other three cements with adhesive failure on the dentin side and cohesive failure in the cured resin. SEM micrographs demonstrated the consistent hybridized dentin in Super-Bond C&B specimens that could resist degradation when immersed in hydrochloric acid followed by NaOCl solutions whereas a detached and degraded interfacial layer was found for the other cements. The results suggest that when complete hybridization of resin into dentin occurs tensile strength at the dentin-cement is higher than at the cement-prosthesis interfaces. The impermeable hybridized dentin can protect the underlying dentin and pulp from acid demineralization, even if detachment of the prosthesis has occurred.

  8. Evaluation of the temperature rise in pulp chamber during class V preparation with Er:YAG laser

    International Nuclear Information System (INIS)

    One of the major concerns regarding laser irradiation in the dentistry field is the overheating in dental tissue, specially pulpal tissue. A temperature raise over 5.5 deg C is considered to be harmful to its vitality. The current study evaluated the temperature increase in the pulp chamber, during class V preparation, performed with the laser Er:YAG in 36 bovine incisive extracted teeth. The samples were eroded on the outer side of the vestibular wall to obtain the dentinal thickness of 2.0 mm (group I), 1.0 mm (group II) and 0.5 mm (group III). Thermocouples were fixed to the inner part of the vestibular wall using thermal paste, through the palatine opening of the samples. Class V cavities were prepared in the vestibular side only in 1 mm2 thick dentins. Irradiation parameters used were: 500 mJ/10 Hz, 850 mJ/10 Hz and 1 000 mJ/10 Hz for all the groups. The results were processed by a microcomputer. This study showed that the temperature increased into the pulpal cavity reached around 3 deg C for the groups I (2,0 mm thick dentine) and II (1.0 mm thick dentine). In the group III (0.5 mm thick) temperature was around 5.5 deg C. Thus, the parameters used for cavity preparation, using Er:YAG laser, were safe in relation to the temperature raise for dentinal thickness of 1,0 and 2,0 mm; in 0.5 mm thick dentins, temperature increase reached 5.5 deg C and an appropriate correction in the laser parameters was necessary. (author)

  9. 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.

  10. Restorasi mahkota logam dengan pasak fiber komposit pada molar permanen muda (Metal crown restoration with fiber composite post in young permanent molar

    Directory of Open Access Journals (Sweden)

    Theresia Dhearine Pratiwi

    2013-09-01

    Full Text Available Background: The first permanent molar has a high prevalence of caries with the most rapid progression in the first two years after eruption. The destruction can extend to the pulp and require endodontic treatment. After endodontic treatment the teeth should have a final restoration due to the possibilities of fracture. The teeth with a few remaining tissue need a restoration such as crown with post and core support. Fiber composite post is widely used today because it has a similar modulus elasticity as dentin. Purpose: The case report was aimed to share the endodontic treatment which was followed by fiber composite post and metal crown insertion on young permanent molar. Case: An 11 years old girls was referred to Pediatric Dentistry clinic at Universitas Indonesia Dental Hospital due to caries #36 that extend to the pulp. Case management: Endodontic treatment with metal crown supported by fiber composite post and composite core was done as final restoration. One month after procedure there was no subjective complaints or inflammation. Conclusion: The case report showed that endodontic treatment followed by fiber composite post and metal crown insertion could be done succesfully on young permanent molar of 11 years old patient.Latar belakang: Gigi molar pertama permanen muda (M1 merupakan gigi dengan angka kejadian karies yang tinggi dengan kerusakan paling cepat terjadi pada dua tahun pertama setelah gigi tersebut erupsi. Kerusakan tersebut dapat mencapai pulpa sehingga diperlukan perawatan endodontik. Gigi yang sudah dirawat memerlukan restorasi akhir yang baik, karena kemungkinan terjadi fraktur. Sisa jaringan gigi yang sedikit membutuhkan restorasi akhir berupa mahkota tiruan dengan dukungan pasak dan inti. Pasak fiber komposit merupakan pasak yang saat ini sering digunakan karena memiliki keunggulan modulus elastisitas yang menyerupai dentin. Tujuan: Tujuan penulisan laporan kasus ini adalah untuk melaporkan perawatan endodontik yang

  11. Eight-year randomized clinical evaluation of Class II nanohybrid resin composite restorations bonded with a one-step self-etch or a two-step etch-and-rinse adhesive

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2015-01-01

    Objectives: The aimof this study is to observe the durability of Class II nanohybrid resin composite restorations, placed with two different adhesive systems, in an 8-year follow-up. Methods: Seventy-eight participants received at random at least two Class II restorations of the ormocer-based nan......Objectives: The aimof this study is to observe the durability of Class II nanohybrid resin composite restorations, placed with two different adhesive systems, in an 8-year follow-up. Methods: Seventy-eight participants received at random at least two Class II restorations of the ormocer......-based nanohybrid resin composite (Ceram X) bonded with either a one-step self-etch adhesive (Xeno III) or a control two-step etch-and-rinse adhesive (Excite). The 165 restorations were evaluated using slightly modified United States Public Health Services (USPHS) criteria at baseline and then yearly during 8 years...... and no significant difference in overall clinical performance between the two adhesives. Fracture was the main reason for failure. Clinical relevance: The one-step self-etch adhesive showed a good long-term clinical effectiveness in combination with the nanohybrid resin composite in Class II restorations....

  12. The effect of CO2 laser irradiation plus fluoride dentifrice on the inhibition of secondary caries on root surfaces adjacent to glass ionomer cement or composite resin restorations

    Science.gov (United States)

    Rodrigues, S. R.; Moraes, M.; Hanashiro, F. S.; Youssef, M. N.; Brugnera Junior, A.; Nobre-dos-Santos, M.; de Souza-Zaroni, W. C.

    2016-02-01

    Although the cariostatic effects of CO2 laser on the root surface have been shown, there is scarce information regarding its effects on root secondary caries. The objective of this research was to investigate the effect of the association of CO2 laser and a fluoride dentifrice on the inhibition of secondary caries on root surfaces adjacent to composite-resin or glass-ionomer-cement restorations. Dental blocks of human roots were divided into two groups: composite resin (CR) or glass ionomer cement (GIC). Subsequently, the blocks were divided into four subgroups (n  =  10): C, non-fluoride dentifrice; FD, fluoride dentifrice; L, CO2 laser with an energy density of 6.0 J cm-2  +  non-fluoride dentifrice; and L  +  FD, CO2 laser  +  fluoride dentifrice. The blocks were subjected to pH cycling to simulate a high cariogenic challenge. Dental demineralization around the restorations was quantified by microhardness analysis. The results were subjected to analysis of variance (ANOVA) and the Tukey-Kramer test (p  ⩽  0.05). As for mineral loss, it can be observed that all the groups that were treated with a fluoride dentifrice and laser, used alone or not, were statistically similar and superior to the RC-C group. It was concluded that CO2 laser irradiation and a fluoride dentifrice used alone or combined with each other are efficient surface treatments for preventing secondary root caries, regardless of the restorative material used.

  13. The Effect of Gamma Radiation on the Bond Strength and Micro leakage of Two Aesthetic Restorative Materials

    International Nuclear Information System (INIS)

    To evaluate the effect of gamma radiation on bond strength and micro leakage of nano-composite and nano-glassionomer, and to detect any alterations in their molecular structure due to gamma radiation. Materials and Methods: 80 specimens were used as follow; 40 specimens for shear bond strength evaluation, 20 specimens for micro leakage assessment, while the remaining 20 specimens for deducing the chemical structure. For shear bond strength (SBS) test 2 mm thick wafers of dentine were sectioned and 3 mm diameter holes were drilled through the wafers. 20 specimens were restored with nano-composite and nano-glassionomer without irradiation (Group A1, B1). The remaining 20 specimens were restored with nano-composite and nano-glassionomer (Group A2, B2), then they were irradiated with therapeutic dose of 60 gray for 1 week (3 days/week). For micro leakage, 10 natural teeth with two prepared class V cavities were used. One of the cavities was restored with nano-composite while the other one with nano-glassionomer to be examined before and after gamma radiation. Spectrophotometric analysis was performed for all tested materials before and after radiation to trace any structural changes. Results: Significant increase in SBS of nano-composite after irradiation while nano-glassionomer was insignificantly increased. For micro leakage no significant difference existed between the irradiated and non-irradiated groups of both materials. Conclusion: Therapeutic dose of head and neck gamma radiation had improved dentin shear bond strength of nano-composite. On the other hand, it had not an effect on shear bond strength of nano-glassionomer and the micro leakage of both tested materials. Gamma radiation did not alter the chemical structure of the tested material.

  14. Radiopacity evaluation of composite restorative resins and bonding agents using digital and film x-ray systems

    OpenAIRE

    Oztas, Bengi; Kursun, Sebnem; Dinc, Gul; Kamburoglu, Kıvanc

    2012-01-01

    Objective: The purpose of this in vitro study was to explore the radiopacity of composite resins and bonding materials using film and phosphor plates. Methods: Nine composite dental resin specimens and human tooth slices were exposed together with an aluminium stepwedge using dental film and phosphor plates. Eight dentin bonding specimens were prepared and exposed in a similar manner. Their radiopacity on film was assessed using a transmission densitometer, and the radiopacity with phosphor p...

  15. Diosmectite-zinc oxide composite improves intestinal barrier restoration and modulates TGF-β1, ERK1/2, and Akt in piglets after acetic acid challenge.

    Science.gov (United States)

    Song, Z-H; Ke, Y-L; Xiao, K; Jiao, L-F; Hong, Q-H; Hu, C-H

    2015-04-01

    The present study evaluated the beneficial effect of diosmectite-zinc oxide composite (DS-ZnO) on improving intestinal barrier restoration in piglets after acetic acid challenge and explored the underlying mechanisms. Twenty-four 35-d-old piglets (Duroc × Landrace × Yorkshire), with an average weight of 8.1 kg, were allocated to 4 treatment groups. On d 1 of the trial, colitis was induced via intrarectal injection of acetic acid (10 mL of 10% acetic acid [ACA] solution for ACA, DS-ZnO, and mixture of diosmectite [DS] and ZnO [DS+ZnO] groups) and the control group was infused with saline. Twenty-four hours after challenged, piglets were fed with the following diets: 1) control group (basal diet), 2) ACA group (basal diet), 3) DS-ZnO group (basal diet supplemented with DS-ZnO), and 4) DS+ZnO group (mixture of 1.5 g diosmectite [DS]/kg and 500 mg Zn/kg from ZnO [equal amount of DS and ZnO in the DS-ZnO treatment group]). On d 8 of the trial, piglets were sacrificed. The results showed that DS-ZnO supplementation improved (P acetic acid-induced colitis by improving mucosa barrier restoration, inhibiting apoptosis, and improving intestinal epithelial cells proliferation and modulation of TGF-β1 and ERK1/2 and Akt signaling pathway.

  16. Evaluation of fracture resistance of endodontically treated teeth restored with composite resin along with fibre insertion in different positions in vitro.

    Science.gov (United States)

    Rahman, Hena; Singh, Shailja; Chandra, Anil; Chandra, Ramesh; Tripathi, Supratim

    2016-08-01

    This study was carried out to compare the different techniques of placement of polyethylene fibre (Ribbond) on reinforcement of endodontically treated teeth with MOD cavities in vitro. Forty extracted human premolars were randomly assigned to four groups (n = 10). Teeth in Groups I-IV received root canal treatment and a MOD cavity preparation, with gingival cavosurface margin 1.5 mm in coronal to cementoenamel junction. Group I served as no fibre group, Group II as occlusal fibre group, Group III as base fibre group and Group IV as dual-fibre group (occlusal and base both). Subsequent to restoring with composite resin and thermocycling, a vertical compressive force was applied at a cross-head speed of 0.5 mm min(-1) using universal testing machine until fracture. Data were analysed using one-way analysis of variance and Tukey's post hoc tests. Fracture resistance was significantly highest in dual-fibre group (P root canal-treated teeth and maximum fracture resistance was observed when cavity was restored using dual-fibre technique. PMID:26419210

  17. Estudo comparativo da infiltração marginal em restaurações de classe V

    Directory of Open Access Journals (Sweden)

    FARIAS Débora Gonçalves de

    2002-01-01

    Full Text Available Este estudo teve como objetivo avaliar o comportamento laboratorial de adesivos dentinários, cimentos ionoméricos modificados por resina e resinas compostas modificadas por poliácidos, no selamento das margens gengivais de cavidades de classe V preparadas na junção amelocementária. Quarenta cavidades foram executadas nas faces vestibular e palatina/lingual de 20 terceiros molares humanos extraídos, e restauradas com os seguintes materiais: grupo 1 (G1- Vitremer (3M; grupo 2 (G2- Vitremer (3M e Syntac Sprint/Tetric Ceram (Vivadent; grupo 3 (G3- Syntac Sprint/Tetric Ceram (Vivadent; grupo 4 (G4- Prime & Bond 2.1/Variglass (Dentsply. Após termociclagem em corante azul de metileno, os espécimes foram seccionados longitudinalmente e analisados em lupa estereoscópica para avaliação do grau de infiltração marginal. Os resultados após teste estatístico de Mann-Whitney revelaram melhor vedamento marginal para o grupo 1, quando comparado com o grupo 4 (p = 0,05, mas não foram demonstradas diferenças significantes entre os demais grupos. Nas condições desse experimento, o material Vitremer ofereceu melhor vedamento marginal que o sistema Prime & Bond 2.1/Variglass.

  18. Comparative study of the influence of cavity preparation with high-speed rotation or Er:YAG laser on infiltration of aesthetic restorations

    Science.gov (United States)

    Costa, D. P. T. S.; Beatrice, L. C. S.; Guerra, L. S. C.; Ribeiro, M. A.; Zanin, F. A. A.; Queiroga, A. S.; Limeira Júnior, F. A.; Gerbi, M. E. M. M.

    2010-04-01

    The aim of the present study was to compare marginal infiltration in Class V cavities prepared on extracted human premolars with either high-speed rotation or a Er:YAG laser. Class V cavities were executed on the vestibular and lingual faces of twelve premolars, with high-speed rotation or a Er:YAG laser (300 mJ, 4 Hz, and 3 W), and cavity surfaces were conditioned with 37% phosphoric acid combined with laser treatment (80 mJ, 5 Hz, 3 W) or without laser treatment in the following manner: G1—high-speed rotation + conditioning with phosphoric acid; G2—high-speed rotation + conditioning with laser and phosphoric acid; G3—laser + conditioning with phosphoric acid; and G4—laser + conditioning with laser and phosphoric acid. Specimens were restored with the composite resin, thermocycled and immersed in 0.5% basic fuchsin for 24 h. Specimens were then cross-cut and analyzed using a stereoscopic magnifying glass. Evaluations were submitted to the Kruskall-Wallis statistical test. No significant differences were found between the averages of the groups ( p > 0.05). High-speed rotation and Er:YAG laser for the confection of cavity preparation exhibited a similar performance with regard to marginal infiltration.

  19. Restoring forests

    DEFF Research Database (Denmark)

    Jacobs, Douglass F.; Oliet, Juan A.; Aronson, James;

    2015-01-01

    Forest loss and degradation is occurring at high rates but humankind is experiencing historical momentum that favors forest restoration. Approaches to restoration may follow various paradigms depending on stakeholder objectives, regional climate, or the degree of site degradation. The vast amount...... of land requiring restoration implies the need for spatial prioritization of restoration efforts according to cost-benefit analyses that include ecological risks. To design resistant and resilient ecosystems that can adapt to emerging circumstances, an adaptive management approach is needed. Global change...

  20. Fracture behavior of structurally compromised non-vital maxillary premolars restored using experimental fiber reinforced composite crowns.

    NARCIS (Netherlands)

    Fokkinga, W.A.; Kreulen, C.M.; Bell-Ronnlof, A.M. Le; Lassila, L.V.; Vallittu, P.K.; Creugers, N.H.J.

    2006-01-01

    PURPOSE: To study the fracture behavior of direct resin composite crowns with or without experimental fiber reinforcement. METHODS: Clinical crowns of single-rooted maxillary premolars were cut off at the cemento-enamel junction. Canals were prepared with Gates Glidden drills up to size 4. No additi

  1. Changes in species composition and diversity in the restoration process of sub-alpine dark brown coniferous forests in western Sichuan Province, China

    Institute of Scientific and Technical Information of China (English)

    Jiangming MA; Shirong LIU; Zuomin SHI; Yuandong ZHANG; Bing KANG; Baoyu CHEN

    2008-01-01

    By adopting the concept of space as a substi-tute for time, we analyzed the dynamics of species com-position and diversity of different restoration sequences (20, 30, 40, 50 years) in two secondary forest types in western Sichuan Province, distributed in a northerly or northwesterly direction. The analysis was based on the results of measurements of 50 plots located at elevations between 3100-3600 m. The forests originated from nat-ural regeneration in combination with reforestation of spruce when the old-growth bamboo-dark brown con-iferous forests and moss-dark brown coniferous old growth forests were harvested. Similar old-growth dark brown coniferous forests at ages ranging between 160 and 200 years were selected as the reference forests for comparisons. We recorded 167 species of vascular plants from 44 families and 117 genera. There was no significant difference in terms of the number of species among secondary forests. But the importance values of dominant species varied during the restoration pro-cesses. The dominant species in the secondary forests is Betula albo-sinensis, while Abiesfaxoniana is the dom-inant species in old-growth dark brown coniferous for-ests. Species richness increased significantly with restoration processes. It increased quickly in secondary forests during the period from 30 to 40 years, but decreased significantly in the old-growth dark brown coniferous forests. The species richness among growth forms decreased in the following order: herb layer> sh-rub layer > tree layer. The maximum value of the even-ness index occurred in secondary forests at age 40 and remained relatively stable in the bamboo-birch forests, but the evenness index tended to decrease in moss-birch forests and slightly increased in the old-growth moss-dark brown coniferous forests. There was a statistically significant difference in the evenness index between the tree and shrub layers as well as between the tree layer and the herb layer, but there was no

  2. Catechol-Functionalized Synthetic Polymer as a Dental Adhesive to Contaminated Dentin Surface for a Composite Restoration.

    Science.gov (United States)

    Lee, Sang-Bae; González-Cabezas, Carlos; Kim, Kwang-Mahn; Kim, Kyoung-Nam; Kuroda, Kenichi

    2015-08-10

    This study reports a synthetic polymer functionalized with catechol groups as dental adhesives. We hypothesize that a catechol-functionalized polymer functions as a dental adhesive for wet dentin surfaces, potentially eliminating the complications associated with saliva contamination. We prepared a random copolymer containing catechol and methoxyethyl groups in the side chains. The mechanical and adhesive properties of the polymer to dentin surface in the presence of water and salivary components were determined. It was found that the new polymer combined with an Fe(3+) additive improved bond strength of a commercial dental adhesive to artificial saliva contaminated dentin surface as compared to a control sample without the polymer. Histological analysis of the bonding structures showed no leakage pattern, probably due to the formation of Fe-catechol complexes, which reinforce the bonding structures. Cytotoxicity test showed that the polymers did not inhibit human gingival fibroblast cells proliferation. Results from this study suggest a potential to reduce failure of dental restorations due to saliva contamination using catechol-functionalized polymers as dental adhesives.

  3. 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 (prestoration. PMID:27252011

  4. Restoring proximal caries lesions conservatively with tunnel restorations

    Directory of Open Access Journals (Sweden)

    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

  5. Comparative quantitative and qualitative assessment of the marginal adaptation and apposition of bonded amalgam restorations using luting glass ionomer and 4-META adhesive liner under a scanning electron microscope. An in vitro study.

    OpenAIRE

    Abraham M; Sudeep P; Bhat K

    1999-01-01

    The present invitro study was conducted to assess the marginal adaptation and apposition of amalgam restorations bonded to tooth structure, using freshly mixed luting glass ionomer cement (type 1) and compared with the much documented material--Amalgam bond (4-META). Twelve freshly extracted human premolar teeth were used and class V cavities were prepared on the buccal and lingual surfaces of twelve teeth for the experimental groups. Buccal cavities (class V) were prepared on twelve other te...

  6. In vitro quantitative evaluation of marginal microleakage in class II restorations confected with a glass ionomer cement and two composite resins

    Directory of Open Access Journals (Sweden)

    BIJELLA Maria Fernanda Borro

    2001-01-01

    Full Text Available This study evaluated, in vitro, marginal microleakage in class II restorations confected with the glass ionomer cement Vitremer and with the composite resins Ariston pHc and P-60. The aims of the study were to assess the effect of thermocycling on those materials and to evaluate two methods utilized in the analysis of dye penetration. Sixty premolars divided in three groups were utilized; the teeth had proximal cavities whose cervical walls were located 1 mm below the cementoenamel junction. Half of the test specimens from each group underwent thermocycling; the other half remained in deionized water, at 37ºC. The specimens were immersed, for 24 hours, in a basic 0.5% fuchsin solution at 37ºC. For the analysis of microleakage, the specimens were sectioned in a mesio-distal direction, and the observation was carried out with the software Imagetools. The results were evaluated through the 2-way ANOVA and through the Tukey?s test. All groups presented marginal microleakage. The smallest values were obtained with Vitremer, followed by those obtained with the composite resins P-60 and Ariston pHc. There was no statistically significant difference caused by thermocycling, and the method of maximum infiltration was the best for detecting the extension of microleakage.

  7. Scanning electron microscopy analysis of marginal adaptation of composite resines to enamel after using of standard and gradual photopolimerization

    Directory of Open Access Journals (Sweden)

    Dačić Stefan

    2014-01-01

    Full Text Available Introduction. Bonding between composite and hard dental tissue is most commonly assessed by measuring bonding strength or absence of marginal gap along the restoration interface. Marginal index (MI is a significant indicator of the efficiency of the bond between material and dental tissue because it also shows the values of width and length of marginal gap. Objective. The aim of this investigation was to estimate quantitative and qualitative features of the bond between composite resin and enamel and to determine the values of MI in enamel after application of two techniques of photopolymerization with two composite systems. Methods. Forty Class V cavities on extracted teeth were prepared and restored for scanning electron microscope (SEM analysis of composite bonding to enamel. Adhesion to enamel was achieved by Adper Single Bond 2 - ASB (3M ESPE, or by Adper Easy One - AEO (3M ESPE. Photopolymerization of Filtek Ultimate - FU (3M ESPE was performed using constant halogen light (HIP or soft start program (SOF. Results. Quantitative and qualitative analysis, showed better mikromorphological bonding with SOF photopolymerization and ASB/FU composite system. Differences in MI between different photopolymerization techniques (HIP: 0.6707; SOF: 0.2395 were statistically significant (p<0.001, as well as differences between the composite systems (ASB/FU: 0.0470; AEO/ FU: 0.8651 (p<0.001 by two-way ANOVA test. Conclusion. Better marginal adaptation of composite to enamel was obtained with SOF photopolymerization in both composite systems.

  8. Esthetic restoration of primary incisors.

    Science.gov (United States)

    Carranza, F; García-Godoy, F

    1999-04-01

    A simple and esthetic technique for restoring cariously involved primary maxillary incisors is described. The technique includes mini-pins, a preformed celluloid crown and resin-based composite. PMID:10477982

  9. Four-year clinical evaluation of Class II nano-hybrid resin composite restorations bonded with a one-step self-etch and a two-step etch-and-rinse adhesive

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2011-01-01

    The objective of this prospective clinical trial was to evaluate the 4-year clinical performance of an ormocer-based nano-hybrid resin composite (Ceram X; Dentsply/DeTrey) in Class II restorations placed with a one-step self-etch (Xeno III; Dentsply/DeTrey) and two-step etch-and-rinse adhesive...

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

    DEFF Research Database (Denmark)

    van Dijken, Jan Wv; Pallesen, Ulla

    2015-01-01

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

  11. Assessment of radiopacity of restorative composite resins with various target distances and exposure times and a modified aluminum step wedge

    Energy Technology Data Exchange (ETDEWEB)

    Bejeh Mir, Arash Poorsattar [Dentistry Student Research Committee (DSRC), Dental Materials Research Center, Dentistry School, Babol University of Medical Sciences, Babol (Iran, Islamic Republic of); Bejeh Mir, Morvarid Poorsattar [Private Practice of Orthodontics, Montreal, Quebec (Canada)

    2012-09-15

    ANSI/ADA has established standards for adequate radiopacity. This study was aimed to assess the changes in radiopacity of composite resins according to various tube-target distances and exposure times. Five 1-mm thick samples of Filtek P60 and Clearfil composite resins were prepared and exposed with six tube-target distance/exposure time setups (i.e., 40 cm, 0.2 seconds; 30 cm, 0.2 seconds; 30 cm, 0.16 seconds, 30 cm, 0.12 seconds; 15 cm, 0.2 seconds; 15 cm, 0.12 seconds) performing at 70 kVp and 7 mA along with a 12-step aluminum stepwedge (1 mm incremental steps) using a PSP digital sensor. Thereafter, the radiopacities measured with Digora for Windows software 2.5 were converted to absorbencies (i.e., A=-log (1-G/255)), where A is the absorbency and G is the measured gray scale). Furthermore, the linear regression model of aluminum thickness and absorbency was developed and used to convert the radiopacity of dental materials to the equivalent aluminum thickness. In addition, all calculations were compared with those obtained from a modified 3-step stepwedge (i.e., using data for the 2nd, 5th, and 8th steps). The radiopacities of the composite resins differed significantly with various setups (p<0.001) and between the materials (p<0.001). The best predicted model was obtained for the 30 cm 0.2 seconds setup (R2=0.999). Data from the reduced modified stepwedge was remarkable and comparable with the 12-step stepwedge. Within the limits of the present study, our findings support that various setups might influence the radiopacity of dental materials on digital radiographs.

  12. 2种复合树脂磨牙充填修复的临床评价%Clinical evaluation of two posterior composite resin restorations

    Institute of Scientific and Technical Information of China (English)

    何治一; 张蓉; 张平虎; 赵信义

    2016-01-01

    目的:用混合评价法比较通用型复合树脂(Z350 XT)和磨牙复合树脂(P60)的临床效果及耐磨耗性能。方法:用Z350 XT和P60随机修复66个磨牙牙合面、邻牙合面缺损,于修复后1、6个月按照改良US-PHS标准对修复体进行评价;同时,用硅橡胶印模材料制取印模,灌制环氧树脂模型用于扫描电镜下观察其表面微形貌,灌制石膏模型用于三维形貌扫描并计算磨耗量。结果:复合树脂修复后1、6个月,Z350 XT 组色泽匹配和表面粗糙度均优于 P60组(P<0.05)。6个月时,修复体表面平均磨耗深度 Z350 XT、P60组分别为(40.84±14.95)μm、(35.03±13.03)μm(P>0.05),磨耗体积分别为(1.20±0.62)mm3、(0.68±0.43)mm3(P>0.05)。扫描电镜观察显示,1、6个月时P60组表面暴露出较大的填料颗粒,导致表面较粗糙。结论:通用型复合树脂Z350 XT色泽匹配性和表面粗糙度优于磨牙复合树脂P60,6个月时2种复合树脂的临床耐磨耗性无显著差异。%AIM:To compare the clinical performance and wear resistance of an universal composite and a posterior composite by a mixed -method approach.METHODS:Z350 XT and P60 composite resin were randomly placed in 66 ClassⅠandⅡcavities respectively in molars(n=33).The restorations were evaluated after 1 -and 6-month according to modified USPHS criteria.Meanwhile,impressions of the restorations were taken using a polyvinyl siloxane impression material and then epoxy resin replicas and stone replicas were prepared for the obseruation of sur-face microstructure under SEMand 3D scanning image to quantify the wear.RESULTS:Z350 XT showed better color matching and surface roughness than P60 (P0.05),and volume los-ses were(1.20 ±0.62)mm3 and(0.68 ±0.43)mm3 respectively(P>0.05).After 1 -and 6-month,the surface of P60 exposed largefillers,resulting ina rougher surfacethan Z350 XT.CONCLUSION:Of Z350

  13. 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.

  14. 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. PMID:12412967

  15. Effect of five commercial mouth rinses on the microhardness of a nanofilled resin composite restorative material: An in vitro study

    Directory of Open Access Journals (Sweden)

    K N Jyothi

    2012-01-01

    Results: Significant reduction in the mean VHN (Vicker′s micro hardness number was observed in all the groups after exposure to the tested mouth rinses (P<0.01 and the reduction in mean VHN values were as follows: Group I 12.09, Group II 3.42, Group II 1.51, Group IV 1.03, Group V 0.57. Inter group comparison showed statistically significant reduction in micro hardness in Groups I and II compared to all other groups with P<0.001. There was no significant difference between Groups III, IV and V. Conclusion: All the mouth rinses showed a reduction in the microhardness of nanofilled resin composite material with listerine (Group I containing maximum amount of alcohol, showing highest reduction in micro hardness value.

  16. Effect of different curing modes on the degree of conversion and the microhardness of different composite restorations

    Directory of Open Access Journals (Sweden)

    Reem Ali Ajaj

    2015-01-01

    Full Text Available Introduction: This study aims to evaluate the effects of different curing units and modes on the degree of conversion (DC and microhardness (MH of two different resin composites [ESTELITE ∑ QUICK (EQ, and Z350 XT (Z3]. Materials and Methods: One hundred (100 discs of each tested material were made and divided into two subgroups (n = 50 according to the discs′ dimensions: 5 mm diameter × 2 mm thickness, and 2 mm diameter × 2 mm thickness. Each subgroup was further subdivided into the following five classes (n = 10: I cured with halogen light curing-unit; II cured with light-emitting diode (LED unit; III cured with argon laser; IV cured with halogen light-curing unit for 5 s, 10 s rest followed by 20 s curing; and V cured with halogen light-curing unit for 10 s, then 10 s rest, followed by 10 s curing. The first subgroup was tested for MH using the Vickers Microhardness tester and the second subgroup was tested for DC using Fourier transform infrared spectroscopy (FTIR. Data were statistically analyzed using two-way analysis of variance (ANOVA and Tukey′s post hoc test P < 0.05. Results: Specimens in class IV showed the highest mean DC and MH, followed by class III, then class II. Class I showed significantly lower mean values for both DC and MH. On the other hand, Z3 showed statistically significantly higher mean DC and MH than EQ. Conclusion: Although the two tested composites did not perform similarly under the test conditions, curing with halogen unit for 5 s, then 10 s rest, followed by 10 s curing improved the DC and the MH of both the tested materials.

  17. A comparison of microhardness of indirect composite restorative materials Estudo comparativo da microdureza de materiais resinosos indiretos

    Directory of Open Access Journals (Sweden)

    Carolina Baptista Miranda

    2003-06-01

    Full Text Available The purpose of this study was to compare the microhardness of four indirect composite resins. Forty cylindrical samples were prepared according to the manufacturer’s recommendations using a Teflon mold. Ten specimens were produced from each tested material, constituting four groups (n=10 as follows: G1 - Artglass; G2 - Sinfony; G3 - Solidex; G4 - Targis. Microhardness was determined by the Vickers indentation technique with a load of 300g for 10 seconds. Four indentations were made on each sample, determining the mean microhardness values for each specimen. Descriptive statistics data for the experimental conditions were: G1 - Artglass (mean ±standard deviation: 55.26 ± 1.15HVN; median: 52.6; G2 - Sinfony (31.22 ± 0.65HVN; 31.30; G3 - Solidex (52.25 ± 1.55HVN; 52.60; G4 - Targis (72.14 ± 2.82HVN; 73.30. An exploratory data analysis was performed to determine the most appropriate statistical test through: (I Levene's for homogeneity of variances; (II ANOVA on ranks (Kruskal-Wallis; (III Dunn's multiple comparison test (0.05. Targis presented the highest microhardness values while Sinfony presented the lowest. Artglass and Solidex were found as intermediate materials. These results indicate that distinct mechanical properties may be observed at specific materials. The composition of each material as well as variations on polymerization methods are possibly responsibles for the difference found in microhardness. Therefore, indirect composite resin materials that guarantee both good esthetics and adequate mechanical properties may be considered as substitutes of natural teeth.O objetivo deste estudo foi comparar a microdureza de 4 resinas compostas indiretas. Quarenta amostras cilíndricas foram obtidas com o auxílio de uma matriz de teflon, seguindo-se as recomendações dos fabricantes. Foram obtidas 10 amostras para cada material testado, contituindo-se 4 grupos (n=10 como se segue: G1-Artglass; G2-Sinfony; G3-Solidex; G4-Targis. A

  18. Direct digital radiography for the detection of defects in a standard aluminium test object through composite resin restorative materials.

    Science.gov (United States)

    Golubow, N A; Farman, A G; von Fraunhofer, J A; Kelly, M S

    1994-05-01

    While the RVG 32000 (Trophy Radiologie, Vincennes, France) is in wide use for direct digital intraoral radiography in dentistry, there is a dearth of information in the literature concerning the system's sensitivity to small changes in radiographic density consistent with initial and recurrent dental caries. A standardized 7 mm aluminium test block was used as a phantom for perceptibility testing of density changes, both with and without the superimposition of composite resin sheets of various thicknesses. Defects in the block were randomly positioned and varied from 0.1 to 1.5 mm. Thermal prints were used for evaluation. Standard linear images, with no enhancement, were compared with three enhanced modes, standard mode with gradient enhancement (enhanced standard), standard X-function and zoom high resolution (ZHR). Sensitivity improved in the following sequence: standard 0.58 < enhanced standard 0.75 < X-function 0.94 < ZHR 0.95. Accuracy improved in the following sequence: standard 0.45 < enhanced standard 0.58 < X-function 0.73 < ZHR 0.74. Specificity was 1.0 both for X-function and for ZHR. These two modes both proved significantly better (P < 0.05) for the detection of 0.1 mm defects than the other two modes tested. No significant difference was found between X-function and ZHR. As ZHR requires four times the radiation exposure as standard exposures with the X-function, the latter is preferred for the task described in this study.

  19. Fracture resistance, two point bending strength and morphological characteristics of pulpless teeth restored with fiber-reinforced composite posts

    Directory of Open Access Journals (Sweden)

    Alfredo Tibúrcio Nunes Pires

    2012-09-01

    Full Text Available Introduction: Fiber-reinforced composite posts (FRC posts have been used for tooth reinforcement after endodontic treatment. The mechanical characteristics of FRC posts can influence the clinical prognostic. Objective: The aim of this study was to evaluate the flexural strength and fracture resistance of commercially available FRC posts Material and methods: Fourteen human single-rooted premolars with completely formed apices were selected and received endodontic treatment. The specimens were divided into two groups related to the post system: i Group A – cylindrical-conical fiber-reinforced post (White post DC, FGM, and ii group B – conical fiber-reinforced post (EXACTO, Angelus. The fracture resistance was evaluated and two point bending tests were carried out. The glass fiber characteristics and the tag penetration of the luting material into the radicular dentin structure were evaluated through scanning electronic microscopy in an illustrative way. One-way ANOVA and Tukey’s HSD test (α = 0.05 were applied. Results: The values obtained for fracture resistance and two point bending test were, respectively, 399.29 N and 109.5 N for group A, and 386.25 N and 119.5 N for group B. No significant differences in strength values among the groups were found. Conclusion: There were no significant statistical differences between the two post groups regarding to fracture strength and two point bending strength. It can be concluded that the posts selected for this study performed satisfactorily in terms of mechanical properties so that they can be used for tooth reinforcement after endodontic treatment.

  20. Comparative Evaluation of Fracture Resistance of Simulated Immature Teeth Restored with Glass Fiber Posts, Intracanal Composite Resin, and Experimental Dentine Posts

    Directory of Open Access Journals (Sweden)

    Vineeta Nikhil

    2015-01-01

    Full Text Available Aim. The aim of this study was to compare the fracture resistance of simulated immature teeth restored with gutta-percha, glass fiber posts (GFP, experimental dentine posts (DP or Intracanal composite Resin (ICR. Materials and Methods. Fifty maxillary canines were decoronated, standardized and enlarged until, number 5 Peeso reamers were allowed to simulate immature teeth. After placement of 5 mm of MTA, the canals were divided into 5 groups and filled as follows: Group 1: AH Plus + gutta-percha, lateral compaction; Group 2: GFP luted with PARACORE dual cure resin; Group 3: DP luted with PARACORE dual cure resin; Group 4: PARACORE dual cure resin. A standardized core was built in all groups except in Group 5. Each of the specimens was tested for fracture resistance by universal testing machine. Results. The mean fracture resistance were 817 ± 27.753, 1164.6 ± 21.624, 994.4 ± 96.8747, 873.8 ± 105.446 and 493.7 ± 6.945 newtons for Groups 1, 2, 3, 4, and 5 respectively. Independent “t” test revealed statistically significant discrepancies, in the fracture resistance among the 4 groups except Group 1 and Group 4 (P<0.05. Conclusions. This study suggests that GFP and DP may be preferred for additional reinforcement of immature teeth.

  1. Comparative evaluation of the effect of cavity disinfectants on the fracture resistance of primary molars restored with indirect composite inlays: An in vitro study

    Directory of Open Access Journals (Sweden)

    Indira M

    2010-01-01

    Full Text Available A study was conducted to evaluate and compare the effect of cavity disinfectants on the fracture resistance of primary molars restored with indirect composite inlays. Thirty-six non-carious primary second molars were selected and divided randomly into three groups (n = 12: control group (no disinfectant, chlorhexidine group (disinfected with 2% chlorhexidine for 40 seconds and sodium hypochlorite group crowns (disinfected with 2% chlorhexidine for 40 seconds. The inlays were fabricated by indirect method using Ceram X nanocomposite on plaster die. All the groups were submitted to compression mechanic test in a Hounsfield universal testing machine at 1 mm/min cross-head speed and the results were calculated in Newtons. Descriptive statistics, independent t test, and one way analysis of variance (ANOVA test revealed the mean fracture resistance of three groups, i.e., control group, chlorhexidine group and sodium hypochlorite group to be 2260.66, 1858.08 and 1310.66, respectively. When intragroup comparisons were made, a significant difference was observed in all the groups (P<0.001. Scheffe′s post hoc test revealed that control group had the highest fracture resistance, followed by chlorhexidine group, and sodium hypochlorite group had the least fracture resistance. Each value differed significantly from the other (P<0.05. Cavity disinfectants used in the present study had detrimental effect on the fracture resistance of primary molars. Among the disinfectants employed in the present study, chlorhexidine showed a better resistance to fracture than sodium hypochlorite.

  2. ramic restorations

    Directory of Open Access Journals (Sweden)

    Ashish R Jain

    2013-01-01

    Full Text Available Rehabilitation of a patient with severely worn dentition after restoring the vertical dimension is a complex procedure and assessment of the vertical dimension is an important aspect in these cases. This clinical report describes the full mouth rehabilitation of a patient who was clinically monitored to evaluate the adaptation to a removable occlusal splint to restore vertical dimension for a period 1 month and provisional restorations to determine esthetic and functional outcome for a period of 3 months. It is necessary to recognizing that form follows function and that anterior teeth play a vital role in the maintenance of oral health. Confirmation of tolerance to changes in the vertical dimension of occlusion (VDO is of paramount importance. Articulated study casts and a diagnostic wax-up can provide important information for the evaluation of treatment options. Alteration of the VDO should be conservative and should not be changed without careful consideration.

  3. One-year clinical evaluation of compomer restorations in cervical lesions of different aetiology

    Directory of Open Access Journals (Sweden)

    Premović Milica

    2012-01-01

    Full Text Available Introduction. The aim of this one-year prospective clinical study was to evaluate the treatment results of compomer restorations (Dyract® eXtra/ Dentsply/De Trey, Konstanz, Germany with a single step self-etching dental adhesive (Xeno® III Dentsply/De Trey, Konstanz, Germany used for restoring class V lesions (non-carious and primary carious cervical lesions. Material and Methods. A total number of 62 class V restorations (n = 62 were placed by one dentist in 30 patients on incisors, canines and premolars. The fillings were placed due to different indications: non-carious cervical defects (n = 32 and primary carious lesions (n = 30. The restorations were evaluated by a single-blind design, according to the Modified United States Public Health Service system 6 and 12 months following the placement. The following were evaluated: retention, marginal integrity, marginal discoloration, wear, postoperative sensitivity and secondary caries. The statistical analysis compared the ratings of each criteria between materials using the Pearson chi-square or Fisher’s exact test at a level of significance of 5% (p<0.05. Results. Two restorations of the non-carious lesion group were lost after 6 months, and after 12 months one restoration was lost in the group of primary carious lesions. There were no statistically significant differences between restorations for all evaluated criteria in both groups. Conclusion. The compomer restorations in combination with a single step self-etching dental adhesive showed acceptable clinical performance in Class V lesions after one year of clinical service.

  4. Site Restoration

    Energy Technology Data Exchange (ETDEWEB)

    Noynaert, L.; Bruggeman, A.; Cornelissen, R.; Massaut, V.; Rahier, A

    2001-04-01

    The objectives, the programme, and the achievements of the Site Restoration Department of SCK-CEN in 2000 are summarised. Main activities include the decommissioning of the BR3 PWR-reactor as well as other clean-up activities, projects on waste minimisation and activities related to the management of decommissioning projects. The department provides consultancy and services to external organisations.

  5. Restorative neuroscience

    DEFF Research Database (Denmark)

    Andres, Robert H; Meyer, Morten; Ducray, Angélique D;

    2008-01-01

    There is increasing interest in the search for therapeutic options for diseases and injuries of the central nervous system (CNS), for which currently no effective treatment strategies are available. Replacement of damaged cells and restoration of function can be accomplished by transplantation of...

  6. The effect of load cycling on microleakage of low shrinkage methacrylate base composite compared with silorane base composite and SEM evaluation of marginal integrity

    Directory of Open Access Journals (Sweden)

    Hamid Kermanshah

    2013-04-01

    Full Text Available Background and Aims: Marginal seal in class V cavity and determination of the best restorative material in reducing microleakage is of great concern in operative dentistry. The aim of this study was to evaluate the effect of load cycling on the microleakage of low shrinkage composites compared with methacrylate-based composites with low shirinkage rate in class V cavity preparation. Marginal integrity of these materials was assessed using scanning electron microscope (SEM. Materials and Methods: In this in vitro study, class V cavity preparations were made on the buccal and lingual surfaces of 48 human premolars and molars (96 cavities. The specimens were divided into four groups each containing 12 teeth (24 cavities: group 1 (Kalore-GC+ G-Bond , group 2 (Futurabond NR+Grandio, group 3(All Bond SE+ Aelite LS Posterior, group 4 (LS System Adhesive Primer & Bond+Filtek P90. All the specimens were thermocycled for 2000 cycles (5-50oC. In each group, half of the specimens (n=12 were subjected to 200,000 cycles of loading at 80 N. Epoxy resin replicas of 32 specimens (4 restorations in each subgroup were evaluated using SEM and the interfacial gaps were measured. Finally, the teeth were immersed in 0.5% basic fuchsin dye for 24 hours at 370C, then sectioned and observed under stereomicroscope. The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests and the comparison between occlusal and gingival microleakage was made with Wilcoxon test. Results: Within unloaded or loaded specimens, there were no significant differences in microleakage among four groups on the occlusal margins (P>0.05. But there were statistically significant differences in microleakage between silorane and Aelite on the gingival margins (P0.05. Conclusion: Silorane did not perform better than the conventional low shrinkage methacrylate-based composite in terms of sealing ability (except Aelite. Cyclic loading did not increase the extent of leakage in any groups.

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

    DEFF Research Database (Denmark)

    Pallesen, U.; Qvist, V.

    2003-01-01

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

  8. Restoring Ancestral Language, Restoring Identity.

    Science.gov (United States)

    Bannon, Kay T.

    1999-01-01

    Describes the Cherokee Language Renewal Program that was designed to help Cherokee elementary school children learn to function in the dominant culture without sacrificing their own cultural heritage. Explains how the program got started, and reports on how it helps restore a cultural identify to a people who are at risk of losing their identity.…

  9. Restoration Process

    Science.gov (United States)

    1979-01-01

    In the accompanying photos, a laboratory technician is restoring the once-obliterated serial number of a revolver. The four-photo sequence shows the gradual progression from total invisibility to clear readability. The technician is using a new process developed in an applications engineering project conducted by NASA's Lewis Research Center in conjunction with Chicago State University. Serial numbers and other markings are frequently eliminated from metal objects to prevent tracing ownership of guns, motor vehicles, bicycles, cameras, appliances and jewelry. To restore obliterated numbers, crime laboratory investigators most often employ a chemical etching technique. It is effective, but it may cause metal corrosion and it requires extensive preparatory grinding and polishing. The NASA-Chicago State process is advantageous because it can be applied without variation to any kind of metal, it needs no preparatory work and number recovery can be accomplished without corrosive chemicals; the liquid used is water.

  10. Fracture Resistance and Failure Mode of Endodontically Treated Premolars Restored with Different Adhesive Restorations

    Directory of Open Access Journals (Sweden)

    Nasrin Sarabi

    2015-03-01

    Full Text Available Introduction: The restoration of endodontically treated teeth is a topic that has been studied extensively but it is still a challenge for dental practitioners. The aim of this study was to evaluate fracture resistance, fracture patterns and fracture location of endodontically treated human maxillary premolars restored with direct and indirect composite resin and ceramic restoration. Methods: Eighty non-carious maxillary premolars were selected and divided into four groups (n=20. Endodontic treatment and mesio-occluso-distal preparations were carried out in all the groups except for the control group (group I. Subsequently, the prepared teeth were restored as follows: group II: indirect composite restoration; group III: ceramic restoration; group IV: direct composite restoration. The specimens were subjected to compressive axial loading until fracture occurred. The mode of failure was also recorded. Results: Group I had higher fracture resistance (1196.82±241.74 than the other groups (P

  11. Does the use of a novel self-adhesive flowable composite reduce nanoleakage?

    Science.gov (United States)

    Naga, Abeer Abo El; Yousef, Mohammed; Ramadan, Rasha; Fayez Bahgat, Sherif; Alshawwa, Lana

    2015-01-01

    Objective The aim of the study reported here was to evaluate the performance of a self-adhesive flowable composite and two self-etching adhesive systems, when subjected to cyclic loading, in preventing the nanoleakage of Class V restorations. Methods Wedge-shape Class V cavities were prepared (4×2×2 mm [length × width × depth]) on the buccal surfaces of 90 sound human premolars. Cavities were divided randomly into three groups (n=30) according to the used adhesive (Xeno® V [self-etching adhesive system]) and BOND-1® SF (solvent-free self-etching adhesive system) in conjunction with Artiste® Nano Composite resin, and Fusio™ Liquid Dentin (self-adhesive flowable composite), consecutively. Each group was further divided into three subgroups (n=10): (A) control, (B) subjected to occlusal cyclic loading (90N for 5,000 cycles), and (C) subjected to occlusal cyclic loading (90N for 10,000 cycles). Teeth then were coated with nail polish up to 1 mm from the interface, immersed in 50% silver nitrate solution for 24 hours and tested for nanoleakage using the environmental scanning electron microscopy and energy dispersive analysis X-ray analysis. Data were statistically analyzed using two-way analysis of variance and Tukey’s post hoc tests (P≤0.05). Results The Fusio Liquid Dentin group showed statistically significant lower percentages of silver penetration (0.55 μ) compared with the BOND-1 SF (3.45 μ) and Xeno V (3.82 μ) groups, which were not statistically different from each other, as they both showed higher silver penetration. Conclusion Under the test conditions, the self-adhesive flowable composite provided better sealing ability. Aging of the two tested adhesive systems, as a function of cyclic loading, increased nanoleakage. PMID:25848318

  12. Comparative evaluation of the effect of different crown ferrule designs on the fracture resistance of endodontically treated mandibular premolars restored with fiber posts, composite cores, and crowns: An ex-vivo study

    Science.gov (United States)

    Dua, Nikita; Kumar, Bhupendra; Arunagiri, D.; Iqbal, Mohammad; Pushpa, S.; Hussain, Juhi

    2016-01-01

    Introduction: In cases of severe hard tissue loss, 2 mm circumferential ferrule is difficult to achieve which leads to incorporation of different ferrule designs. Aim: To compare and evaluate the effect of different crown ferrule designs on the fracture resistance of mandibular premolars restored with fiber posts, composite cores, and crowns. Materials and Methods: Fifty freshly extracted mandibular premolars were endodontically treated and divided into five groups: Group I - 2 mm circumferential ferrule above the cementoenamel junction (CEJ); Group II - 2 mm ferrule on the facial aspect above CEJ; Group III - 2 mm ferrule on the lingual aspect above CEJ; Group IV - 2 mm ferrule on the facial and lingual aspects above CEJ with interproximal concavities, and Group V - no ferrule (control group) and were later restored with fiber posts, composite cores, and crowns. Specimens were mounted on a universal testing machine, and compressive load was applied at a crosshead speed of 1 mm/min until fracture occurred. Results: The results showed that circumferential ferrule produced the highest mean fracture resistance and the least fracture resistance was found in the control group. Conclusion: Circumferential ferrule increases the fracture resistance of endodontically treated teeth restored with bonded post, core, and crown. PMID:27217642

  13. Does the use of a novel self-adhesive flowable composite reduce nanoleakage?

    Directory of Open Access Journals (Sweden)

    Abo El Naga A

    2015-03-01

    Full Text Available Abeer Abo El Naga,1 Mohammed Yousef,1 Rasha Ramadan,2,3 Sherif Fayez Bahgat,4,5 Lana Alshawwa6 1Operative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; 2Operative Dentistry Department, Modern Science and Arts University, Cairo, Egypt; 3Operative Dentistry Department, Dentistry Program, Batterjee Medical College, Jeddah, Saudi Arabia; 4Fixed Prosthodontics Department, Modern Science and Arts University, Cairo, Egypt; 5Fixed Prosthodontics Department, Dentistry Program, Batterjee Medical College, Jeddah, Saudi Arabia; 6Medical Education Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia Objective: The aim of the study reported here was to evaluate the performance of a self-adhesive flowable composite and two self-etching adhesive systems, when subjected to cyclic loading, in preventing the nanoleakage of Class V restorations. Methods: Wedge-shape Class V cavities were prepared (4×2×2 mm [length × width × depth] on the buccal surfaces of 90 sound human premolars. Cavities were divided randomly into three groups (n=30 according to the used adhesive (Xeno® V [self-etching adhesive system] and BOND-1® SF (solvent-free self-etching adhesive system in conjunction with Artiste® Nano Composite resin, and Fusio™ Liquid Dentin (self-adhesive flowable composite, consecutively. Each group was further divided into three subgroups (n=10: (A control, (B subjected to occlusal cyclic loading (90N for 5,000 cycles, and (C subjected to occlusal cyclic loading (90N for 10,000 cycles. Teeth then were coated with nail polish up to 1 mm from the interface, immersed in 50% silver nitrate solution for 24 hours and tested for nanoleakage using the environmental scanning electron microscopy and energy dispersive analysis X-ray analysis. Data were statistically analyzed using two-way analysis of variance and Tukey's post hoc tests (P≤0.05. Results: The Fusio Liquid Dentin group showed

  14. Site Restoration

    International Nuclear Information System (INIS)

    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. 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.

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

    Institute of Scientific and Technical Information of China (English)

    邓剑兰; 查伯涛

    2013-01-01

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

  17. In vitro evaluation of marginal and internal adaptation after occlusal stressing of indirect class II composite restorations with different resinous bases

    OpenAIRE

    Dietschi, Didier; Olsburgh, Steven; Krejci, Ivo; Davidson, Carel

    2003-01-01

    Composite inlays are indicated for large cavities, which frequently extend cervically into dentin. The purpose of this study was to compare in vitro the marginal and internal adaptation of class II fine hybrid composite inlays (Herculite, Kerr) made with or without composite bases, having different physical properties. Freshly extracted human molars were used for this study. The base extended up to the cervical margins on both sides and was made from Revolution (Kerr), Tetric flow (Vivadent),...

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

    Science.gov (United States)

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

    1989-09-01

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

  19. Composites

    OpenAIRE

    Zhao, Hanqing; Guo, Yuanzheng

    2014-01-01

    This thesis was a literature study concerning composites. With composites becoming increasingly popular in various areas such as aerospace industry and construction, the research about composites has a significant meaning accordingly. This thesis was aim at introducing some basic information of polymer matrix composites including raw mate-rial, processing, testing, applications and recycling to make a rough understanding of this kind of material for readers. Polymeric matrices, fillers,...

  20. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2010-01-01

    New Year is an open composition to be realised by improvising musicians. It is included in "From the Danish Seasons" (see under this title). See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You...

  1. Effects of 10%sodium ascorbate on microleakage of composite resin restorations after external bleaching%10%抗坏血酸钠对外漂白后复合树脂充填体微渗漏的影响

    Institute of Scientific and Technical Information of China (English)

    韩艳彦; 杜嵘; 朱亚琴

    2015-01-01

    Objective To investigate the effects of 10%sodium ascorbate, 10%sodium ascorbate com-bined with a surfactan(Tween,0.2%) on the microleakage of composite resin restorations after external tooth bleaching with 10% carbamide peroxide. Methods Fifty extracted human premolars, intact and health, were randomly divided into five groups:group 1, direct composite resin filling without bleaching;group 2, composite resin filling immediately after bleaching with 10%carbamide peroxide;group 3, immersed in artificial saliva for three weeks after bleaching, then filled by composite resin;group 4, cavity treated with 10%sodium ascorbate after bleaching and then filled by composite resin;group 5, cavity treated with 10%sodium ascorbate combined with 0.2%Tween after bleaching and then filled by composite resin. After 2000 thermal cycles, teeth were immersed in 2%methylene blue for 24 hours, then the microleakage at resin/deatin interface was observed under stereomicro-scope. Results Group 1 displayed the least amount of microleakage, while group 2 showed the greatest amount of microleakage, group 3 and group 4 behaved similarly to group 2, having great amount of microleakage, show-ing no significant difference (P>0.05);the microleakage of group 5 decreased significantly (P0.05);第5组渗漏值较第2组及第4组显著下降(P<0.05)。结论10%过氧化脲外漂白致复合树脂充填体边缘微渗漏明显增加,含0.2%Tween的10%抗坏血酸钠处理窝洞可以有效减少该微渗漏的增加,延迟充填和单纯使用抗坏血酸钠均不能有效减少微渗漏。

  2. XRF, μ-XRD and μ-spectroscopic techniques for revealing the composition and structure of paint layers on polychrome sculptures after multiple restorations.

    Science.gov (United States)

    Franquelo, M L; Duran, A; Castaing, J; Arquillo, D; Perez-Rodriguez, J L

    2012-01-30

    This paper presents the novel application of recently developed analytical techniques to the study of paint layers on sculptures that have been restored/repainted several times across centuries. Analyses were performed using portable XRF, μ-XRD and μ-Raman instruments. Other techniques, such as optical microscopy, SEM-EDX and μ-FTIR, were also used. Pigments and other materials including vermilion, minium, red lac, ivory black, lead white, barium white, zinc white (zincite), titanium white (rutile and anatase), lithopone, gold and brass were detected. Pigments from both ancient and modern times were found due to the different restorations/repaintings carried out. μ-Raman was very useful to characterise some pigments that were difficult to determine by μ-XRD. In some cases, pigments identification was only possible by combining results from the different analytical techniques used in this work. This work is the first article devoted to the study of sculpture cross-section samples using laboratory-made μ-XRD systems. PMID:22284518

  3. 排龈技术在牙体缺损修复中的应用%Clinical performance of using gingival retraction cord and composite resin for dental restoration

    Institute of Scientific and Technical Information of China (English)

    姜醒; 陈榕凯; 赵月香; 王海亮

    2009-01-01

    目的 观察排龈对3MZ250复合树脂修复牙体缺损疗效的影响.方法 选择31例120颗唇颊面牙颈部龋缺损牙,随机分为实验组和对照组,每组60颗,经窝洞预备后,实验组排龈线排龈后3MZ250复合树脂修复,对照组直接树脂修复,随访2年,评价修复体保存、继发龋以及边缘密合状况.结果 充填后1周复查,使用排龈线组修复后悬突的发生率低于对照组,差异有显著性(P<0.01).充填后0.5年复查两组脱落率无明显差异;1年及2年后复查实验组充填体的脱落率明显低于对照组(P<0.05).结论 排龈可提高3MZ250复合树脂修复牙体缺损的修复体保存率,可以作为一项常规使用措施.%Objective To study the clinical performance by using gingival retraction cord and complex resin for dental restoration after two years.Methods One hundred and twenty teeth with dental caries or defects of 31 patients were selected. The teeth were divided into 2 groups randomly. In group 1, dental caries were removed and cavities were prepared routinely, and filled with composite resin after using retraction cord to retract gingival. In group 2, caries were removed and filled directly. The marginal adaptation, retention and the presence of secondary caries after six months, one year and two years were evaluated.Results One week after restoration, the incidence of overhanging dental restorations by using retraction cord to retract gingival were significantly lower than those of the control group (P<0.01). After 6 months, statistical analysis showed no differences between the two groups in the retention of restorations (P>0.05). However, after 1 year and 2 years , the retention of restorations in the control group was significantly lower than that of using retraction cord (P<0.05).Conclusion Gingival retraction cord has high successful rate of composite resin for restoration of dental caries or defects.

  4. In vitro evaluation of marginal and internal adaptation after occlusal stressing of indirect class II composite restorations with different resinous bases.

    Science.gov (United States)

    Dietschi, Didier; Olsburgh, Steven; Krejci, Ivo; Davidson, Carel

    2003-02-01

    Composite inlays are indicated for large cavities, which frequently extend cervically into dentin. The purpose of this study was to compare in vitro the marginal and internal adaptation of class II fine hybrid composite inlays (Herculite, Kerr) made with or without composite bases, having different physical properties. Freshly extracted human molars were used for this study. The base extended up to the cervical margins on both sides and was made from Revolution (Kerr), Tetric flow (Vivadent), Dyract (Detrey-Dentsply) or Prodigy (Kerr), respectively. Before, during and after mechanical loading (1 million cycles, with a force varying from 50 to 100 N), the proximal margins of the inlay were assessed by scanning electron microscopy. Experimental data were analysed using non-parametric tests. The final percentages of marginal tooth fracture varied from 30.7% (no base) to 37.6% (Dyract). In dentin, percentages of marginal opening varied from 9.2% (Tetric Flow) to 30.1% (Prodigy), however, without significant difference between base products. Mean values of opened internal interface with dentin varied from 11.06% (Tetric Flow) to 28.15% (Prodigy). The present results regarding dentin adaptation confirmed that the physical properties of a base can influence composite inlay adaptation and that the medium-rigid flowable composite Tetric Flow is a potential material to displace, in a coronal position, proximal margins underneath composite inlays.

  5. Soil inoculation steers restoration of terrestrial ecosystems.

    Science.gov (United States)

    Wubs, E R Jasper; van der Putten, Wim H; Bosch, Machiel; Bezemer, T Martijn

    2016-01-01

    Many natural ecosystems have been degraded because of human activities(1,2) and need to be restored so that biodiversity is protected. However, restoration can take decades and restoration activities are often unsuccessful(3) because of abiotic constraints (for example, eutrophication, acidification) and unfavourable biotic conditions (for example, competition or adverse soil community composition). A key question is what manageable factors prevent transition from degraded to restored ecosystems and what interventions are required for successful restoration(2,4). Experiments have shown that the soil community is an important driver of plant community development(5-8), suggesting that manipulation of the soil community is key to successful restoration of terrestrial ecosystems(3,9). Here we examine a large-scale, six-year-old field experiment on ex-arable land and show that application of soil inocula not only promotes ecosystem restoration, but that different origins of soil inocula can steer the plant community development towards different target communities, varying from grassland to heathland vegetation. The impact of soil inoculation on plant and soil community composition was most pronounced when the topsoil layer was removed, whereas effects were less strong, but still significant, when the soil inocula were introduced into intact topsoil. Therefore, soil inoculation is a powerful tool to both restore disturbed terrestrial ecosystems and steer plant community development. PMID:27398907

  6. [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.

  7. Training, simulation, restoration expert system for power grid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The paper introduces some technology for training, simulation, restoration expert system of power grid, the structure of the system including function composition, hardware and software composition are discussed, knowledge representation and the method to establish device graphical library for expert system are given, the fault setting and diagnosis for training and simulation as well as restoration technology with deep first searching arithmetic and heuristic inference are presented. The research provides a good base for developing the training, simulation, restoration system of power companies.

  8. 直接树脂修复与间接树脂嵌体的临床应用比较%Clinical comparison on restoring posterior teeth with composite resin fillings and indirect resin inlays

    Institute of Scientific and Technical Information of China (English)

    洪席超; 文静; 于世德

    2012-01-01

    Objective To evaluate the clinical performance of resin fillings and inlays in restoring the posterior teeth.Methods 46 posterior teeth were filled with composite resin directly and 50 posterior teeth were restored with indirect resin inlays.Each restoration was evaluated at baseline,after 1 year and 2 years,according to the modified USPHS criteria.Results There was significant difference in marginal discoloration,marginal integrity,secondary carries and wear-resistance between these two groups (P<0.05).The achievement ratio of direct resin fillings was 72.2% and the achievement ratio of indirect resin inlays was 91.3% Conclusion Indirect resin inlays can be suitable for restorations of posterior teeth with more physical property,with less irritation or microleakage.%目的 比较复合树脂及树脂嵌体用于修复后牙缺损的临床治疗效果.方法 选择82例患者,共96颗后牙,临床完成直接树脂修复46个,树脂嵌体50个,术后即刻、1年及2年,参考改良USPHS标准,观察其临床效果.结果 直接树脂修复和间接树脂嵌体修复在边缘着色、边缘密合、继发龋、耐磨性等方面差异有显著性(P<0.05),直接树脂修复成功率为72.2%(26/36),间接树脂嵌体成功率为91.3%(42/ 46).结论 树脂嵌体具有更好的边缘密合性、抗磨损和抗折裂能力,同时对牙髓的刺激更小.

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

    Directory of Open Access Journals (Sweden)

    Maria Cecília Caldas Giorgi Tolosa

    2005-06-01

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

  10. Linking restoration ecology with coastal dune restoration

    Science.gov (United States)

    Lithgow, D.; Martínez, M. L.; Gallego-Fernández, J. B.; Hesp, P. A.; Flores, P.; Gachuz, S.; Rodríguez-Revelo, N.; Jiménez-Orocio, O.; Mendoza-González, G.; Álvarez-Molina, L. L.

    2013-10-01

    Restoration and preservation of coastal dunes is urgently needed because of the increasingly rapid loss and degradation of these ecosystems because of many human activities. These activities alter natural processes and coastal dynamics, eliminate topographic variability, fragment, degrade or eliminate habitats, reduce diversity and threaten endemic species. The actions of coastal dune restoration that are already taking place span contrasting activities that range from revegetating and stabilizing the mobile substrate, to removing plant cover and increasing substrate mobility. Our goal was to review how the relative progress of the actions of coastal dune restoration has been assessed, according to the ecosystem attributes outlined by the Society of Ecological Restoration: namely, integrity, health and sustainability and that are derived from the ecological theory of succession. We reviewed the peer reviewed literature published since 1988 that is listed in the ISI Web of Science journals as well as additional references, such as key books. We exclusively focused on large coastal dune systems (such as transgressive and parabolic dunefields) located on natural or seminatural coasts. We found 150 articles that included "coastal dune", "restoration" and "revegetation" in areas such as title, keywords and abstract. From these, 67 dealt specifically with coastal dune restoration. Most of the studies were performed in the USA, The Netherlands and South Africa, during the last two decades. Restoration success has been assessed directly and indirectly by measuring one or a few ecosystem variables. Some ecosystem attributes have been monitored more frequently (ecosystem integrity) than others (ecosystem health and sustainability). Finally, it is important to consider that ecological succession is a desirable approach in restoration actions. Natural dynamics and disturbances should be considered as part of the restored system, to improve ecosystem integrity, health and

  11. Microleakage of bonded amalgam restorations: effect of thermal cycling.

    Science.gov (United States)

    Helvatjoglou-Antoniades, M; Theodoridou-Pahini, S; Papadogiannis, Y; Karezis, A

    2000-01-01

    This study examined the effect of thermal cycling on the microleakage of bonded amalgam restorations. Three dental amalgam alloys and a gallium alloy were tested with two adhesive resin systems and copal varnish as a control. Class V cavity preparations were prepared on 168 freshly extracted premolars or molars. The preparations were placed parallel to and 1.0 mm occlusal to the cementoenamel junction (CEJ). Four groups of 42 teeth each were treated with one of the following adhesive dentin systems: Bond-It, All-Bond 2/Resinomer or a copal varnish (Copalite). The four groups of 42 teeth each were then restored with one of three dental amalgams: Orosphere Plus, Indiloy, Oralloy or a Gallium alloy (Galloy), resulting in 12 test groups of 14 teeth each. The specimens were stored in double distilled water at 37 degrees C for 24 hours. Final contouring and polishing of the restorations were performed under water spray. Half of the restorations in each group were thermocycled for 3000 cycles (5 degrees C-37 degrees C-55 degrees C-37 degrees C) with a dwell time of 15 sec at each temperature. The other half were stored in double distilled water at 37 degrees C for 24 hours. Then all 168 restorations were stained with dye, sectioned and scored for microleakage. Results showed that the adhesive dentin systems reduced microleakage in amalgam restorations compared to copal varnish only in non-thermocycled specimens. Statistical analysis of the results showed that there was an extremely significant difference (p 0.05) among thermocycled specimens. The reduction of microleakage was not significantly different between Bond-It and All-Bond 2/Resinomer in non-thermocycled specimens. Oralloy showed the most microleakage in the non-thermocycled groups when compared to the other alloys using the same adhesive liner. PMID:11203837

  12. Effect on Micro-Leakage of Composite Resoration with Two Different Adhesives after Bleaching

    Directory of Open Access Journals (Sweden)

    Nazish Fatima

    2015-03-01

    Full Text Available OBJECTIVE: To evaluate the effects of two different adhesive systems after bleaching with 38% Hydrogen peroxide onmicroleakage of Class V composite resin restorations. MATERIALS & METHODS: The materials used in this study included Nano composite (Filtek Z350, Scotchbond™ Dual Cure Dental Adhesive (3M™ ESPE™, Prime and bond elect (Dentsply and Power whitening gel (White Smile 2011, Germany. Sixty sound human premolars were stored in thymol solution (Buffered 0.1% pH 7.00 for about one week. Class V cavities were prepared on the buccal and lingual surfaces of the teeth. The cavities measured 1.5mm in depth, 2mm in occlusogingival dimension (1mm coronal to CEJ and 1mm apical to CEJ and 3mm mesiodistally. The teeth were randomly divided into two groups (n = 30 based on the adhesive system used. In group 1, Scotchbond™ and in group 2, Prime & Bond were used on cavity walls according to manufacturer’s instructions. Filtek Z350 composite resin was used to restore the cavities. Teeth were dried and bleached with Power whitening gel 38 % Hydrogen peroxide for 14 days for 2 hours daily. The specimens were then stored in airtight containers containing 10ml of 5% solution of Methylene blue dye (MERCK and kept in an incubator at 37°C. After storage teeth were dissected then evaluated under a stereomicroscope (Motic DMW-143-FBGC HongKong. Data of microleakage between two materials was examined by Mann-Whitney’s U test. The threshold for level of significance was set to be at-most 0.05 value. RESULTS: The mean microleakage from, Scotchbond™ Universal Adhesive was 3.1 ± 0.5 with median 3.0 (0.5 whereas mean microleakage from Prime and bond elect was 3.7 ± 0.2 with median 3.7 (0.4. Results from Mannwhitney U’s test implied microleakage of Prime and bond elect was significantly more as compare to Scotchbond™ Universal Adhesive material (P < 0.0001. CONCUSION: Microleakage after bleaching with 38% Hydrogen peroxide with Prime and bond elect

  13. Longevity of posterior dental restorations and reasons for failure.

    Science.gov (United States)

    Kopperud, Simen E; Tveit, Anne Bjørg; Gaarden, Torunn; Sandvik, Leiv; Espelid, Ivar

    2012-12-01

    Tooth-coloured restorative materials are being used increasingly more often in Class II preparations in permanent teeth. Using a practice-based study design, we aimed to assess the survival time of Class II restorations and to identify factors relevant to their longevity. Class II restorations (n = 4,030), consisting of resin composites (81.5%), compomers (12.7%), amalgams (4.6%), and glass-ionomer cement restorations (1.2%), were placed in 1,873 patients with a median age of 15 yr. In total, 92.7% of restorations were placed due to primary caries and 5.8% were replacements. After an average follow-up period of 4.6 yr, 61.6% of the restorations were successful, 11.2% had failed, and 27.2% were not available for evaluation (owing to patient drop-out). The mean annual failure rate was 2.9% for resin-composite restorations and 1.6% for amalgams. For resin-composite restorations, secondary caries was the most common reason for replacement (73.9%), followed by loss (8.0%), fracture (5.3%), and marginal defects (2.4%). Multilevel Cox-regression analyses identified young age of the patient, high previous caries experience, deep cavities, and saucer-shaped preparation technique as predisposing to shorter longevity of resin-composite restorations. One brand of resin composite had a shorter survival time than the others. PMID:23167471

  14. Restoring primary anterior teeth: updated for 2014.

    Science.gov (United States)

    Waggoner, William F

    2015-01-01

    The purpose of this paper was to review the current literature associated with the techniques and materials for the restoration of primary anterior teeth and make clinical recommendations based upon the available literature. A variety of esthetic restorative materials are available to utilize for restoring primary incisors. Awareness of the specific strengths, weakness, and properties of each material can 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. 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 crowns that are luted onto the tooth and are either some type of stainless steel or zirconia crown. There is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. Operator preferences, esthetic demands by parents, the child's behavior, the amount of tooth structure remaining, and moisture and hemorrhage control are all variables that affect the decision and ultimate outcome of whatever restorative solution is chosen. PMID:25905657

  15. Body composition and menstrual status in adults with a history of anorexia nervosa-At what fat percentage is the menstrual cycle restored?

    DEFF Research Database (Denmark)

    Al-Dakhiel Winkler, Laura; Stampe Frølich, Jacob; Schulpen, Maya;

    2016-01-01

    OBJECTIVE: To study the association between body composition measures and menstrual status in a large sample of adult patients with a history of anorexia nervosa and to calculate the predicted probability of resumption of menstrual function. Furthermore, to establish whether fat percentage...... is superior to body mass index in predicting the resumption of menses. METHOD: One hundred and thirteen adult women with a history of anorexia nervosa underwent a dual energy X-ray absorptiometry (DXA) scan and completed questionnaires regarding medication prescription and menstrual function. RESULTS: Fifty...

  16. Clinical evaluation of resin composite restorations used to treat localised posterior tooth wear%后牙病理性磨损树脂修复的临床效果探讨

    Institute of Scientific and Technical Information of China (English)

    江琴; 童锦发; 戴杰

    2012-01-01

    目的:观察用直接树脂充填法和间接树脂充填法修复后牙病理性磨损的临床效果.方法:选择后牙(牙合)面有病理性磨损且具有充填空间的患者48例,患牙144颗,其中有牙本质过敏症状者38例98颗牙.患者按门诊顺序随机分为直接法修复组和间接法修复组2组各24例,在不备洞的情况下分别采用可乐丽菲露复合树脂直接或间接修复,比较治疗3个月及1年后树脂充填的临床效果、牙本质敏感情况和咀嚼效率改变情况.结果:治疗后3个月时复查,直接法和间接法两组患牙树脂充填体A级率无显著性差异(卡方检验,P>O.05);治疗1年后复查,间接法组患牙树脂充填体A级率优于直接法组,两组差异有统计学意义(卡方检验,P<0.05).间接法组牙本质敏感治疗总有效率优于直接法组,两组差异有统计学意义(卡方检验,P<0.05).治疗3个月及治疗1年后,间接法组的咀嚼效率高于直接法,两组差异有统计学意义(t检验,P<0.01).结论:间接树脂法比直接树脂充填法修复后牙病理性磨损有较好的临床效果.%Objective: To evaluate the clinical performance of direct and indirect resin composite restorations used to treat localized posterior tooth wear. Methods: A total of 144 pathological wore posterior teeth with restorable space in oc-clusal surface in 48 patients, 98 of which in 38 patients with dentin sensitive symptom, were randomized block designed into two groups. The control group: 69 posterior teeth wear in 24 patients were filled with Clearfil AP-X resin composite directly, the experimental group: 75 posterior teeth wear in 24 patients were filled with Clearfil AP-X resin composite indirectly. The restorations were evaluated according to the modified the United States Public Health Service (USPHS) criterion after 3 months and 1 year. The patients'clinical symptom and masticatory efficiency were also compared before and after treatment. Results: There was no

  17. everStick复合树脂高强纤维材料修复前牙过小缺失间隙%everStick Fibre reinforced composites for too small anterior edentulous space restoration

    Institute of Scientific and Technical Information of China (English)

    贾爽; 王德芳

    2014-01-01

    背景:利用everStick复合树脂高强纤维材料制作的纤维增强复合树脂黏结桥是近年发展起来的一种微创伤固定修复技术,因其备牙量少、黏结成功率高、美观效果好、机械性能强、易于口内修理等优点,受到患者和临床医生的一致好评。目的:探讨everStick复合树脂高强纤维材料用于修复前牙过小缺牙间隙的优势。方法:选择上颌侧切牙缺失且缺失间隙较小的患者23例,采用芬兰StickTech公司生产的everStick复合树脂高强纤维制作黏结桥,修复过小缺牙间隙。结果与结论:采用everStick复合树脂高强纤维制作成黏结桥,修复前牙过小缺牙间隙时,可避免固定义齿对邻牙牙体制备时的磨耗,也避免了传统活动义齿显现卡环不美观及舒适度差等情况的发生。经6-30个月的临床随访观察,23例复诊患者的黏结桥修复体均无松动、无脱黏、折裂和过度磨耗,无继发龋,修复体边缘无明显染色,黏结界面良好,色泽稳定,美观效果好。患者对此种材料完成的修复非常满意。结果表明复合树脂高强纤维修复前牙过小缺失间隙具有抗磨性能良好,机械强度高,色泽稳定,对基牙损伤小,美观效果好的优势。%BACKGROUND:The fiber-reinforced composite resin adhesion fixed bridge produced by everStick fibre reinforced composites is a kind of minimaly invasive fixed prosthesis technology in recent years, which is wel thought of patients and clinicians because of its smal tooth preparation, high success rate of bonding, good esthetic effects, strong mechanical properties and easy to intraoral repair. OBJECTIVE:To investigate the advantage of everStick fibre reinforced composites on too smal anterior edentulous space restoration. METHODS:A total of 23 patients with maxilary lateral incisor missing and with smal edentulous space were colected and renovated with everStick fibre reinforced

  18. Comparing the reinforcing effects of a resin modified glassionomer cement, Flowable compomer, and Flowable composite in the restoration of calcium hydroxide-treated immature roots in vitro

    Directory of Open Access Journals (Sweden)

    S Prathibha Rani

    2011-01-01

    Full Text Available One hundred and sixty human permanent central incisors were enlarged to a 120 file size after crown removal procedure to simulate immature teeth. The root canals were filled with calcium hydroxide and stored for 15 days (phase I, 30 days (phase II, 90 days (phase III, and 180 days (Phase IV. At the end of these selected time periods, calcium hydroxide was cleaned off the root canals of forty teeth that were randomly selected and obturated with gutta-percha points in the apical 2 mm of the root canals with a sealer. The specimens were further equally divided into four groups. Unrestored Group I served as control and the root canals of teeth in the other three group specimens were reinforced with resin modified glassionomer cement (RMGIC (Group II, Flowable Compomer (Group III, and Flowable Composite (Group IV, respectively, using a translucent curing post. All specimens were subjected to compressive force using an Instron Testing machine, until fracture occurred. All the materials evaluated substantially reinforced the root specimens compared to the control. At the end of 180 days, Flowable composites showed maximum reinforcement compared to the other groups; however, no significant differences were found between the reinforcement capabilities of Flowable Compomer and RMGIC.

  19. 不同抛光时机对复合树脂边缘微渗漏的影响%Effect of different polishing time on microleakage of resin composite restorations

    Institute of Scientific and Technical Information of China (English)

    汪轶; 柳娟; 朱铭颐; 韩俊力

    2011-01-01

    PURPOSE: To evaluate the effect of different polishing time on microleakage of different resin composite restorations (Filtek Z350 and Filtek Z250). METHODS: Standardized preparation (the box-type cavities, 3 mm in length and width,2 mm in depth) was performed at the cemento-enamel junction on buccal surface of 80 premolars.They were randomly divided into two groups ,and restored with composite resin ( Filtek Z350 or Filtek Z250). According to polishing time, the specimens of each group were randomly classified into four subgroups. They were the subgroups of no polishing, polishing immediately after restoring, polishing after 10 minutes and polishing after 24 hours. All of the restorations were polished with Sof-lex discs. After thermal circulation and soaked for 24 hours in 2% methyl blue solution, the specimens were cut through the midline of the restoration, the microleakage at the occlusal margin and the gingival margin were observed under a stereomicroscope and the leakage depth was measured with Spot version 4.6 software package. The microleakage degree and microleakage depth of different groups were analyzed with SPSS 17.0 software package for Mann -Whitney U test and Kruskal - Wallis test. RESULTS: The microleakage depth of Filtek Z350 groups were (0.655 ± 0.486)mm,(0.626±0.497)mm,(0.648±0.370)mm and (0.639±0.453)mm,respectively. The microleakage depths of Filtek Z250 groups were (0.785±0.553)mm, (0.763±0.491 )mm, (0.749±0.608)mm and (0.715±0.588)mm,respectively. No significant differences (P>0.05) of microleakage was found among the different groups and subgroups. CONCLUSION: The polishing system of Sof-lex discs have no significant influence on microleakage of resin composite restorations at different polishing time. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (08DZ2271100,08JC1414500) and Innovation Program of Shanghai Municipal Education Commission (09ZZ116).%目的:评价不同抛光时机对不

  20. 流动性复合树脂洞衬对Ⅰ类洞洞壁收缩应力的影响%Efficacy of flowable composite resin as stress-absorbing liners in Class I cavity restorations

    Institute of Scientific and Technical Information of China (English)

    赵信义; 张文彦; 李石保; 李雅萍; 龚旭

    2013-01-01

    Objective To evaluate the efficacy of flowable composite resin (FCR) as stressabsorbing liners in Class I cavity restorations in vitro.Methods Thirty Class Ⅰ cavities of 4 mm in diameter and 2 mm in depth were prepared in polycarbonate(PC) plates and divided into three groups,ten each.After application of an adhesive,cavities in each group were restored using one of the following methods:A:restored with Charisma without any lining of FCR; B:lined with Revolution Formula 2 twice before restoration with Charisma; C:lined with Teric Flow twice before restoration with Charisma.All cavities were observed under a photoelastic microscope and photoelastic images were recorded at 3 min and 24 h after curing and the shrinkage stresses on the cavity wall were calculated.The polymerization shrinkage(v%) of the three composite resins was measured using bonded discs method and their elastic moduli were measured according to ISO standard.Results The shrinkage stresses at 3 min and 24 h of the three methods were as follows,A:(4.93 ± 0.28),(5.87 ± 0.40) MPa,B:(4.90 ± 0.30),(5.84 ± 0.33)MPa,and C:(4.76 ± 0.28),(5.83 ± 0.37) MPa.No significant difference was found in results among different groups.The polymerization shrinkage(v%) in group A,B,and C were (2.63 ±0.04)%,(4.56 ±0.06)%,and (3.98 ±0.02)%.The elastic modulus in group A,B,and C were (9.59 ±0.65),(4.25 ±0.51),and (5.41 ±0.79) GPa.Conclusions Under present study condition,using a FCR as stressabsorbing liner under composite resin restoration does not significantly decrease the polymerization shrinkage stresses at the cavity wall.%目的 观察流动性复合树脂洞衬对普通复合树脂充填Ⅰ类洞洞壁收缩应力的影响,为流动性复合树脂的临床应用提供参考.方法 在聚碳酸酯板上制备直径4 mm、深2 mm的窝洞30个,使用粘接剂后将窝洞分为3组(每组10个)进行充填修复.无洞衬组:直接充填复合树脂A(Charisma);洞衬1组:

  1. 不同因素影响复合树脂边缘微渗漏的体外研究%In vitro study of the effects of different factors on microleakage of resin composite restorations

    Institute of Scientific and Technical Information of China (English)

    孙晨; 李纾

    2013-01-01

    AIM: To investigate the effects of adhesive systems, lining materials and the resin matrices on the marginal microleakage of composite resin restorations. METHODS: Class II cavities were prepared on 100 freshly extracted molars. The molars were then randomly divided into 5 groups (re =20) and the cavities were filled with 3M Adper Easy One + 3M Z250 (Group A) , 370g/L phosphoric acid + 3M Adper Single Bond 2 + 3M Z250 (Group B) , 3M Adper Easy One +3M Light Cure Glass Ionomer + 3M Z250 (Group C) , 3M Adper Easy One + 3M Flow-able Restorative + 3M Z250 (Group D) and 3M P90 system adhesive + 3M P90 (Group E). After thermocycling and Indian ink dyeing, all specimens were sectioned in mesio-distal direction. The dye penetration depth was observed and measured under stereomicroscope. RESULTS: The mean microleakage of group E was significantly less than that of the other groups ( P 0 05). CONCLUSION: The microleakage of P90 restoration is low. Lining by light-cured glass ionomer can decrease the microleakage of composite resin. Total-etch adhesive and self-etch adhesives have no significantly different effects on the microleakage of composite resin.%目的:观察不同粘结系统、不同垫底材料,不同树脂基质对复合树脂边缘微渗漏的影响.方法:按标准在100个新鲜离体磨牙制备邻(牙合)面洞后,随机分为5组(n=20),分别用3M自酸蚀粘结剂+3MZ250复合树脂充填(A组);370 g/L磷酸酸蚀剂+3M全酸蚀粘结剂+3M Z250复合树脂充填(B组);3M自酸蚀粘结剂+3M光固化玻璃离子垫底+3M Z250复合树脂充填(C组);3M自酸蚀粘结剂+3M流动树脂垫底+3M Z250复合树脂充填(D组);3M P90粘结系统+3M P90复合树脂充填(E组).所有试件经过冷热循环、印度墨水染色,近远中向切片后,在体视显微镜下观察测量染料渗透深度.结果:E组(P90)的微渗漏均数明显小于其余各组(P<0.05);C组的微渗漏均数明显小于A组、B组和D组(P<0.05);A、B、D3组间两

  2. Composites

    Science.gov (United States)

    Taylor, John G.

    The Composites market is arguably the most challenging and profitable market for phenolic resins aside from electronics. The variety of products and processes encountered creates the challenges, and the demand for high performance in critical operations brings value. Phenolic composite materials are rendered into a wide range of components to supply a diverse and fragmented commercial base that includes customers in aerospace (Space Shuttle), aircraft (interiors and brakes), mass transit (interiors), defense (blast protection), marine, mine ducting, off-shore (ducts and grating) and infrastructure (architectural) to name a few. For example, phenolic resin is a critical adhesive in the manufacture of honeycomb sandwich panels. Various solvent and water based resins are described along with resin characteristics and the role of metal ions for enhanced thermal stability of the resin used to coat the honeycomb. Featured new developments include pultrusion of phenolic grating, success in RTM/VARTM fabricated parts, new ballistic developments for military vehicles and high char yield carbon-carbon composites along with many others. Additionally, global regional market resin volumes and sales are presented and compared with other thermosetting resin systems.

  3. Macroinvertebrate community assembly in pools created during peatland restoration.

    Science.gov (United States)

    Brown, Lee E; Ramchunder, Sorain J; Beadle, Jeannie M; Holden, Joseph

    2016-11-01

    Many degraded ecosystems are subject to restoration attempts, providing new opportunities to unravel the processes of ecological community assembly. Restoration of previously drained northern peatlands, primarily to promote peat and carbon accumulation, has created hundreds of thousands of new open water pools. We assessed the potential benefits of this wetland restoration for aquatic biodiversity, and how communities reassemble, by comparing pool ecosystems in regions of the UK Pennines on intact (never drained) versus restored (blocked drainage-ditches) peatland. We also evaluated the conceptual idea that comparing reference ecosystems in terms of their compositional similarity to null assemblages (and thus the relative importance of stochastic versus deterministic assembly) can guide evaluations of restoration success better than analyses of community composition or diversity. Community composition data highlighted some differences in the macroinvertebrate composition of restored pools compared to undisturbed peatland pools, which could be used to suggest that alternative end-points to restoration were influenced by stochastic processes. However, widely used diversity metrics indicated no differences between undisturbed and restored pools. Novel evaluations of restoration using null models confirmed the similarity of deterministic assembly processes from the national species pool across all pools. Stochastic elements were important drivers of between-pool differences at the regional-scale but the scale of these effects was also similar across most of the pools studied. The amalgamation of assembly theory into ecosystem restoration monitoring allows us to conclude with more certainty that restoration has been successful from an ecological perspective in these systems. Evaluation of these UK findings compared to those from peatlands across Europe and North America further suggests that restoring peatland pools delivers significant benefits for aquatic fauna by

  4. Macroinvertebrate community assembly in pools created during peatland restoration.

    Science.gov (United States)

    Brown, Lee E; Ramchunder, Sorain J; Beadle, Jeannie M; Holden, Joseph

    2016-11-01

    Many degraded ecosystems are subject to restoration attempts, providing new opportunities to unravel the processes of ecological community assembly. Restoration of previously drained northern peatlands, primarily to promote peat and carbon accumulation, has created hundreds of thousands of new open water pools. We assessed the potential benefits of this wetland restoration for aquatic biodiversity, and how communities reassemble, by comparing pool ecosystems in regions of the UK Pennines on intact (never drained) versus restored (blocked drainage-ditches) peatland. We also evaluated the conceptual idea that comparing reference ecosystems in terms of their compositional similarity to null assemblages (and thus the relative importance of stochastic versus deterministic assembly) can guide evaluations of restoration success better than analyses of community composition or diversity. Community composition data highlighted some differences in the macroinvertebrate composition of restored pools compared to undisturbed peatland pools, which could be used to suggest that alternative end-points to restoration were influenced by stochastic processes. However, widely used diversity metrics indicated no differences between undisturbed and restored pools. Novel evaluations of restoration using null models confirmed the similarity of deterministic assembly processes from the national species pool across all pools. Stochastic elements were important drivers of between-pool differences at the regional-scale but the scale of these effects was also similar across most of the pools studied. The amalgamation of assembly theory into ecosystem restoration monitoring allows us to conclude with more certainty that restoration has been successful from an ecological perspective in these systems. Evaluation of these UK findings compared to those from peatlands across Europe and North America further suggests that restoring peatland pools delivers significant benefits for aquatic fauna by

  5. Composite resin inlay in the restoration of enamel defects in deciduous molars%复合树脂嵌体修复乳磨牙缺损的临床观察

    Institute of Scientific and Technical Information of China (English)

    周铸民; 丁桂聪; 陈晶; 宋宁; 石培荔

    2011-01-01

    Objective To investigate the efficacy of composite resin inlay in the restoration of enamel defects in deciduous molars.Methods 203 deciduous molars with enamel defects were randomly assigned to receive composite resin inlay ( 99 molars,resin-inlay group ),or direct composite resin filing ( 104 molars,resin-filling group ).All the molars were examined one year after restoration; and the modified USPHS-criteria was used for assessment.Results The clinical success rate differed significantly between the resin-inlay group and the resin-filling group in retention,marginal adaptation,secondary caries,gingival index,reaction of the pulp,and abrasion level ( 94.9%,92.9%,90.9%,92.9%,94.9%,and 88.9% in the former group; P< 0.05 ).Although the clinical success rate of color match was higher in the group with resin-inlay ( 87.9% ) than in the group with resin-filling,but there was no significant difference between the two groups ( P > 0.05 ).Conclusion Composite resin inlay is more efficacious than direct composite resin filling.%目的 观察复合树脂嵌体修复乳磨牙牙体缺损的临床效果.方法 对乳磨牙牙体缺损分别采用复合树脂嵌体技术和复合树脂直接充填修复,复合树脂嵌体技术组99例,复合树脂直接充填修复104例;1年后复诊检查,评价标准采用改良USPHS评价标准.结果 复合树脂嵌体技术组的临床成功率在固位情况(94.9%)、边缘密合度(92.9%)、继发龋(90.9%)、牙龈指数(92.9%)、牙髓反应(94.9%)、磨耗程度(88.9%)指标上高于复合树脂直接充填修复组,并且差异有显著性(P< 0.05).在色泽协调性指标上,临床成功率(87.9%)虽高于复合树脂直接充填修复组,但统计学上差异无显著性(P> 0.05).结论 复合树脂嵌体修复术组临床效果优于复合树脂直接充填组.

  6. 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.

  7. Watershed Restoration Project

    Energy Technology Data Exchange (ETDEWEB)

    Julie Thompson; Betsy Macfarlan

    2007-09-27

    In 2003, the U.S. Department of Energy issued the Eastern Nevada Landscape Coalition (ENLC) funding to implement ecological restoration in Gleason Creek and Smith Valley Watersheds. This project was made possible by congressionally directed funding that was provided through the US Department of Energy, Energy Efficiency and Renewable Energy, Office of the Biomass Program. The Ely District Bureau of Land Management (Ely BLM) manages these watersheds and considers them priority areas within the Ely BLM district. These three entities collaborated to address the issues and concerns of Gleason Creek and Smith Valley and prepared a restoration plan to improve the watersheds’ ecological health and resiliency. The restoration process began with watershed-scale vegetation assessments and state and transition models to focus on restoration sites. Design and implementation of restoration treatments ensued and were completed in January 2007. This report describes the restoration process ENLC undertook from planning to implementation of two watersheds in semi-arid Eastern Nevada.

  8. Fracture resistance of posterior teeth restored with modern restorative materials

    OpenAIRE

    Ibrahim M. Hamouda; Shehata, Salah H.

    2011-01-01

    We studied the fracture resistance of maxillary premolars restored with recent restorative materials. Fifty maxillary premolars were divided into five groups: Group 1 were unprepared teeth; Group 2 were teeth prepared without restoration; Group 3 were teeth restored with tetric ceram HB; Group 4 were teeth restored with InTen S; and Group 5 were teeth restored with Admira. The samples were tested using a universal testing machine. Peak loads at fracture were recorded. The teeth restored with ...

  9. Microhardness evaluation around composite restorations using fluoride-containing adhesive systems Avaliação da microdureza ao redor de restaurações de compósito confeccionadas com sistemas adesivos contendo fluoretos

    Directory of Open Access Journals (Sweden)

    Cláudia Silami de Magalhães

    2005-09-01

    Full Text Available The purpose of this study was to evaluate the microhardness of dental enamel around composite restorations bonded with fluoride-containing adhesive systems (FCAS, after thermo- and pH-cycling protocols. Standardized cylindrical cavities were prepared on enamel surfaces of 175 dental fragments, which were randomly assigned into seven experimental groups (n=25. Four groups used FCAS: Optibond Solo (OS; Prime&Bond 2.1 (PB; Syntac Sprint (SS and Tenure Quick (TC. Other groups consisted of "Sandwich" technique restoration (STR (glass ionomer liner + hydrophobic adhesive resin /restorative composite or used Single Bond with (SB or without (SBWC cycling protocols. Adhesive systems were applied according to manufacturers' instructions and cavities were restored with a microfilled composite (Durafill VS. After finishing and polishing, all groups were submitted to 1,000 thermal cycles (5 ºC and 55 ºC and to demineralization (pH 4.3 and remineralization (pH 7.0 cycling protocols, except for SBWC group. The Knoop microhardness of enamel surfaces were measured around restorations. Indentations were recorded at 150, 300 and 450-mm from the cavity wall. Data were analyzed by two-way ANOVA and Duncan's Test (a=0.05%. Means ± SD of enamel microhardness for the groups were (Kg/mm²: SBWC: 314.50 ± 55.93ª ; SB: 256.78 ± 62.66b; STR: 253.90 ± 83.6b; TQ: 243.93 ± 68.3b; OS: 227.97 ± 67.1c; PB: 213.30 ± 91.3d; SS: 208.73 ± 86.6d. Means ± SD of microhardness for the distances 150, 300, 450mm from the cavity wall were, respectively: 234.46 ± 77.81ª; 240.24 ± 85.12ª; 262.06 ± 79.46b. SBWC group, which was not submitted to thermo- and pH-cycling protocols, showed the highest enamel microhardness mean value and the FCAS resulted in lower microhardness values. At 450 mm from the cavity wall, the enamel microhardness increased significantly.O objetivo deste estudo foi avaliar a microdureza do esmalte dental ao redor de restaurações em compósito que

  10. Restoring Damaged Aquatic Ecosystems

    OpenAIRE

    Cairns, John

    2006-01-01

    Aquatic ecosystems must play a major role to ensure that water, which is both essential and scarce, is always available for both present and future generations. This has become even more urgent in light of the ongoing increase in total world population and predicted changes in the world climate. Since aquatic ecosystems have been damaged at a rate far in excess of both natural restoration and anthropogenic restoration, it is essential that both restorative processes be accelerated. However, e...

  11. 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...... of the target ecosystem should be established with the need for restoration carefully assessed and the outcome properly monitored. Finally, we identify the most important challenges that need to be solved in order to carry out efficient restoration with powerful and long-term positive impacts on biodiversity...

  12. Evaluation of the dental structure loss produced during maintenance and replacement of occlusal amalgam restorations

    OpenAIRE

    Fernanda Sardenberg; Clarissa Calil Bonifácio; Mariana Minatel Braga; José Carlos Pettorossi Imparato; Fausto Medeiros Mendes

    2008-01-01

    The aim of this in vitro study was to evaluate four different approaches to the decision of changing or not defective amalgam restorations in first primary molar teeth concerning the loss of dental structure. Ditched amalgam restorations (n = 11) were submitted to four different treatments, as follows: Control group - polishing and finishing of the restorations were carried out; Amalgam group - the ditched amalgam restorations were replaced by new amalgam restorations; Composite resin group -...

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

    Directory of Open Access Journals (Sweden)

    Sameer Jadhav

    2011-01-01

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

  14. 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......-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 years follow-up with modified USPHS criteria. Dentin bonding efficiency was determined by the percentage of lost restorations. Results: 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, 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...

  15. Ghost suppression in image restoration filtering

    Science.gov (United States)

    Riemer, T. E.; Mcgillem, C. D.

    1975-01-01

    An optimum image restoration filter is described in which provision is made to constrain the spatial extent of the restoration function, the noise level of the filter output and the rate of falloff of the composite system point-spread away from the origin. Experimental results show that sidelobes on the composite system point-spread function produce ghosts in the restored image near discontinuities in intensity level. By redetermining the filter using a penalty function that is zero over the main lobe of the composite point-spread function of the optimum filter and nonzero where the point-spread function departs from a smoothly decaying function in the sidelobe region, a great reduction in sidelobe level is obtained. Almost no loss in resolving power of the composite system results from this procedure. By iteratively carrying out the same procedure even further reductions in sidelobe level are obtained. Examples of original and iterated restoration functions are shown along with their effects on a test image.

  16. Time is no healer: increasing restoration age does not lead to improved benthic invertebrate communities in restored river reaches.

    Science.gov (United States)

    Leps, Moritz; Sundermann, Andrea; Tonkin, Jonathan D; Lorenz, Armin W; Haase, Peter

    2016-07-01

    Evidence for successful restoration of riverine communities is scarce, particularly for benthic invertebrates. Among the multitude of reasons discussed so far for the lack of observed effects is too short of a time span between implementation and monitoring. Yet, studies that explicitly focus on the importance of restoration age are rare. We present a comprehensive study based on 44 river restoration projects in Germany, focusing on standardized benthic invertebrate sampling. A broad gradient ranging from 1 to 25years in restoration age was available. In contrast to clear improvements in habitat heterogeneity, benthic community responses to restoration were inconsistent when compared to control sections. Taxon richness increased in response to restoration, but abundance, diversity and various assessment metrics did not respond clearly. Restoration age was a poor predictor of community composition and community change, as no significant linear responses could be detected using 34 metrics. Moreover, only 5 out of 34 tested metrics showed non-linear shifts at restoration ages of 2 to 3years. This might be interpreted as an indication of a post-restoration disturbance followed by a re-establishment of pre-restoration conditions. BIO-ENV analysis and fourth-corner modeling underlined the low importance of restoration age, but revealed high importance of catchment-scale characteristics (e.g., ecoregion, catchment size and land use) in controlling community composition and community change. Overall, a lack of time for community development did not appear to be the ultimate reason for impaired benthic invertebrate communities. Instead, catchment-scale characteristics override the effectiveness of restoration. To enhance the ecological success of future river restoration projects, we recommend improving water quality conditions and catchment-scale processes (e.g., connectivity and hydrodynamics) in addition to restoring local habitat structure. PMID:27046138

  17. Indirect resin composites

    OpenAIRE

    Nandini Suresh

    2010-01-01

    Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses. Indirect composites offer an esthetic alternative to ceramics for posterior teeth. This review article focuses on the material aspect of the newer generation of composites. This review was based on a PubMed database search ...

  18. Bearing restoration by grinding

    Science.gov (United States)

    Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

    1976-01-01

    A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

  19. Influence of filler existence on microleakage of a self-etch adhesive system

    NARCIS (Netherlands)

    H. Mirmohammadi; K. Khosravi; K. Kashani; C.J. Kleverlaan; A.J. Feilzer

    2014-01-01

    Aim: This study evaluated the effect of filler existence in self-etch adhesive resin on the marginal leakage of a class V restoration. Materials and Methods: Class V cavities were prepared and restored with a resin composite on the buccal surfaces of 48 premolars lined with unfilled or filled adhesi

  20. Evaluation of efficacy of restorative dental treatment provided under general anesthesia at hospitalized pediatric dental patients of Isfahan

    Directory of Open Access Journals (Sweden)

    Alireza Eshghi

    2012-01-01

    Conclusion: Stainless steel crown restorations had significantly better results vs other posterior restorations. The failure rates of stainless steel crown and anterior composite resin build-up restorations did not correlate with the time of follow-up in comparison of other restorations.

  1. 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.

  2. 流动树脂垫衬联合高强度流动树脂修复牙邻(牙合)面洞的疗效分析%High-intensity Flowable Composite after Lining with Flowable Composite in Restoring Class ⅡCavi ty

    Institute of Scientific and Technical Information of China (English)

    汪磊

    2015-01-01

    【目的】探讨流动树脂垫衬联合高强度流动树脂在牙邻(牙合)面洞修复治疗中的疗效。【方法】选取接受牙邻(牙合)面洞修复的患者164例,根据修复方法不同分为观察组与对照组,观察组采用流动树脂垫衬联合高强度流动树脂修复,对照组采用“三明治”技术修复。两组治疗后6个月及1年采用改良的USPHS临床修复体质量评估疗效并比较。【结果】修复6个月及12个月后观察组患者修复体边缘着色及术后牙本质敏感症的发生率均显著低于对照组,其差异均有统计学意义( P <0.05);但两组修复体完整性和继发龋发生率的比较均无统计学差异( P >0.05)。【结论】流动树脂垫衬联合高强度流动树脂在牙邻(牙合)面洞患者修复中的疗效显著,可降低患者的术后牙本质敏感症反应,恢复患牙的形态和美观。%[Objective] To explore the clinical efficacies of high‐intensity flowable composite after lining with flowable composite in restoring classⅡcavity .[Methods]A total of 164 patients with classⅡcavity at our hospital from January 2013 to September 2014 were randomly divided into experiment and control groups .The teeth in experiment group were restored with high‐intensity flowable composite after lining with flowable com‐posite while sandwich technique was employed for control group .The modified United States Public Health Service (USPHS) criteria were used to evaluate the treatment outcomes after 6 months and 1 year .[Results]The success rates of marginal discoloration and postoperative sensitivity were higher in experimental group than those in control group . No significant difference existed between restoration integrity and secondary caries .[Conclusion]ClassⅡcavity may be satisfactorily treated with high‐intensity flowable composite after lining with flowable composite .And postoperative sensitivity is lowered and teeth

  3. Restoration of ailing wetlands.

    Directory of Open Access Journals (Sweden)

    Oswald J Schmitz

    2012-01-01

    Full Text Available It is widely held that humankind's destructive tendencies when exploiting natural resources leads to irreparable harm to the environment. Yet, this thinking runs counter to evidence that many ecological systems damaged by severe natural environmental disturbances (e.g., hurricanes can restore themselves via processes of natural recovery. The emerging field of restoration ecology is capitalizing on the natural restorative tendencies of ecological systems to build a science of repairing the harm inflicted by humans on natural environment. Evidence for this, for example, comes from a new meta-analysis of 124 studies that synthesizes recovery of impacted wetlands worldwide. While it may take up to two human generations to see full recovery, there is promise, given human will, to restore many damaged wetlands worldwide.

  4. 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.

  5. Technologies for lake restoration

    OpenAIRE

    Helmut KLAPPER

    2003-01-01

    Lakes are suffering from different stress factors and need to be restored using different approaches. The eutrophication remains as the main water quality management problem for inland waters: both lakes and reservoirs. The way to curb the degradation is to stop the nutrient sources and to accelerate the restoration with help of in-lake technologies. Especially lakes with a long retention time need (eco-) technological help to decrease the nutrient content in the free water. The microbial and...

  6. SUSTENTAÇÃO DE ESMALTE COM IONÔMEROS DE VIDRO E RESINA COMPOSTA: EFEITO NA RESISTÊNCIA À FRATURA DAS CÚSPIDES DE DENTES RESTAURADOS SUPPORTING ENAMEL WITH GLASS IONOMER CEMENT AND COMPOSITE RESIN: EFFECT ON FRACTURE RESISTANCE OF CUSPS OF RESTORED TEETH

    Directory of Open Access Journals (Sweden)

    Angelo Stefano SECCO

    1997-10-01

    Full Text Available Este estudo determinou a resistência e o tipo de fratura do esmalte suportado pelos materiais restauradores ionômeros de vidro convencional e modificado por resina e resina composta, bem como a influência dessa técnica restauradora na resistência das cúspides dos dentes. A remoção da estrutura dental para o preparo de cavidades tipo classe II e a presença de esmalte socavado diminuiram significativamente a resistência das cúspides dos dentes em relação ao dente hígido (p This study determined the resistance to fracture and its pattern for enamel supported with conventional and modified glass ionomer cements, and composite resin restorative materials, as well as the influence of these restorative techniques on cuspal strength of teeth. Removal of dental structure by class II cavity preparations and unsupported enamel had decreased significantly the cuspal strength in relation to healthy teeth (p < 0.01. Restorative materials used to support enamel reduced the fracture rate of restored cusps, but did not increase the fracture resistance values statistically. All tested groups presented alterations in the fracture pattern

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

    Institute of Scientific and Technical Information of China (English)

    王玫

    2014-01-01

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

  8. Resin composites

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  9. Estudio in vitro de microfiltración en obturaciones de clase II de resina compuesta condensable: an in vitro study Microleakage of class II condensable resin composite restorations

    Directory of Open Access Journals (Sweden)

    FJ. Lois Mastach

    2004-04-01

    Full Text Available Objetivo: El propósito de este estudio es evaluar la microfiltración en cavidades de clase II con márgenes gingivales situados en esmalte, obturadas con resina compuesta Surefil®. Material y métodos: 104 cavidades preparadas en dientes humanos extraídos fueron distribuidas al azar en cuatro grupos (n = 26 según la técnica de obturación empleada: grupo I, inserción en bloque; grupo II, inserción en bloque con una base de compómero fluido; grupo III, inserción incremental; grupo IV, inserción incremental con una base de compómero fluido. Las muestras fueron almacenadas en agua durante 24 horas, termocicladas 500 veces entre 5° y 55° C, sumergidas en una solución de fucsina básica al 0,5% durante 24 horas, seccionadas longitudinalmente y examinadas para evaluar la microfiltración. Resultados: El grupo I presentó una microfiltración marginal significativa mente superior que los grupos II, III y IV. Conclusión: Aunque ninguna de las técnicas de obturación empleadas pudo evitar completamente la microfiltración, tanto la técnica incremental como el uso de Dyract flow® como base cavitaria la redujeron significativamente.Objective: The purpose of this study was to evaluate microleakage in Class II cavities with gingival margins in enamel, restored with the condensable resin composite Surefil, placed with a bulk or an incremental filling technique and with or without a liner. Method and materials: 104 cavities prepared on extracted human teeth were randomly distributed into four treatment groups (n=26: group I, bulk filling technique; group II, bulk filling technique with Dyract flow liner; group III, incremental filling technique; group IV, incremental filling technique with Dyract flow liner. Samples were stored in water for 24 hours, thermocycled between 5°C and 55°C for 500 cycles, stained with 0.5% basic fuchsin dye for 24 hours, sectioned longitudinally and scored for microleakage. Results: Group I showed significantly

  10. Long-Term Clinical Performance of Aesthetic Restorations in Primary Molars: A Case Report

    OpenAIRE

    Pomarico, Luciana; Neves, Beatriz Gonçalves; Maia, Lucianne Cople; Primo, Laura Guimarães

    2011-01-01

    There is a great diversity of restorative materials and techniques for deciduous molars with significant coronal destruction, including resin composite restorations and biologic restorations (portions of natural teeth). By using 4 evaluation methods, this study aimed at longitudinally evaluating the effectiveness of restorations in the deciduous molars of a patient having high caries activity, using adhesive techniques. The evaluation methods consisted of the fibre-optic transillumination met...

  11. Restoration of Shoulder Function.

    Science.gov (United States)

    Boe, Chelsea C; Elhassan, Bassem T

    2016-08-01

    Restoration of shoulder function in patients with brachial plexus injury can be challenging. Initial reported efforts were focused on stabilizing the shoulder, improving inferior subluxation and restoring abduction and flexion of the joint. Recent advancements and improved understanding of coordinated shoulder motion and the biomechanical properties of the muscles around the shoulder applicable to tendon transfer have expanded available surgical options to improve shoulder function, specifically external rotation. Despite the advances in reconstructive options, brachial plexus injury remains a serious problem that requires complex surgical solutions, prolonged recovery, and acceptance of functional loss. PMID:27387074

  12. Enamel hypoplasia: challenges of esthetic restorative treatment.

    Science.gov (United States)

    Ruschel, Vanessa Carla; Araújo, Élito; Bernardon, Jussara Karina; Lopes, Guilherme Carpena

    2016-01-01

    Enamel defects, such as white or yellow-brown spots, usually cause problems that are more esthetic than functional. Enamel hypoplasia may be the result of hereditary, systemic, or local factors. Dental trauma is a local etiologic factor. It is relatively common in the primary dentition and can cause defects on the surface of permanent successors. Treatment for such defects can differ, depending on the depth of the spots. For deeper white-spot lesions, a composite resin restoration may be necessary. This is an excellent mode of treatment, due to both its low cost and its conservation of healthy tooth structure. The objective of this case report is to describe composite resin restoration of a maxillary central incisor affected by enamel hypoplasia.

  13. Enamel hypoplasia: challenges of esthetic restorative treatment.

    Science.gov (United States)

    Ruschel, Vanessa Carla; Araújo, Élito; Bernardon, Jussara Karina; Lopes, Guilherme Carpena

    2016-01-01

    Enamel defects, such as white or yellow-brown spots, usually cause problems that are more esthetic than functional. Enamel hypoplasia may be the result of hereditary, systemic, or local factors. Dental trauma is a local etiologic factor. It is relatively common in the primary dentition and can cause defects on the surface of permanent successors. Treatment for such defects can differ, depending on the depth of the spots. For deeper white-spot lesions, a composite resin restoration may be necessary. This is an excellent mode of treatment, due to both its low cost and its conservation of healthy tooth structure. The objective of this case report is to describe composite resin restoration of a maxillary central incisor affected by enamel hypoplasia. PMID:27599287

  14. Challenges of ecological restoration

    DEFF Research Database (Denmark)

    Halme, Panu; Allen, Katherine A.; Aunins, Ainars;

    2013-01-01

    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 ecosys...

  15. [Influence of implant restoration on traditional restoration idea].

    Science.gov (United States)

    Liu, H C

    2016-01-01

    Implant restoration affected the traditional restoration idea. Artificial implant restoration has a profound influence on the design of dental restoration. Implant supported prostheses have not only changed the method of oral rehabilitation, but also integrated revolutionary concept with the traditional treatment protocol. By using implants, posterior missing molars can be effectively restored and thus eliminating the disadvantages of traditional removable partial denture for Kennedy classification Ⅰ, Ⅱ partically edentulous dentition. Full edentulous arch can also be restored with implant fixed denture which provide much better oral health related quality of life compared with the traditional complete denture. It is useful to master the theory and skills of artificial implant restoration, and to provide a reference for the restoration of oral physiological function.

  16. Clinical results of large defect teeth or flared roots restored by fiber posts and resin composites core in combination with full crowns%纤维桩核冠修复牙体严重缺损的临床效果观察

    Institute of Scientific and Technical Information of China (English)

    王贯新; 白保晶; 魏永杰

    2011-01-01

    目的 观察纤维桩树脂核全冠修复牙体严重缺损和薄弱根管的临床修复效果.方法 选择牙体大面积缺损和薄弱根管患者165例219个患牙为研究对象.患牙经根管治疗后行纤维桩树脂核伞冠修复,修复完成后6个月、1年、2年进行临床复查,其中牙体缺损达龈下行牙龈切除术或冠延长术的患牙,增加修复后1个月和3个月临床复查,评价其临床修复效果.结果 165例的219个患牙中,有4例出现纤维桩与根管壁完整脱落,均未见根折、根裂,重新粘固后未见异常.其余215个患牙修复体未出现脱落,冠边缘密合,牙周正常,219个患牙均未出现基牙松动.结论 应用纤维桩树脂核全冠修复牙体严重缺损和薄弱根管可以达到满意的临床修复效果.%Objective To observe the clinical results of fiber post and resin composite core for the repair of large defect teeth or flared roots. Methods A total of 219 large defect teeth or flared roots from 165 patients were restored by fiber posts and resin composite core as well as full crowns. The clinical results of the restorations were followed up for a minimum of six months. Results Four of the 219 restorations failed but the roots remained intact and re-bonded with the previous post-and-core crowns. The restorations and periodontal tissues of the other 215 teeth were normal and successful. Conclusion Fiber post and resin composite core system is reliable for restoring large defect teeth or flared roots with satisfactory clinical results.

  17. Restoring proximal caries lesions conservatively with tunnel restorations

    OpenAIRE

    Chu, CH; Mei, L.; Cheung, C.; Nalliah, RP

    2013-01-01

    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, suc...

  18. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors

    Science.gov (United States)

    Grover, Rashu

    2012-01-01

    ABSTRACT Restoration of primary incisors, which have been severely damaged by rampant caries or trauma, is a difficult task for the pediatric dentist. With the introduction of new adhesive systems and restorative materials, alternative approaches for treating these teeth have been proposed. This paper discusses the restoration of carious primary maxillary incisors using composite resin restoration reinforced with fiberglass post. Two case reports are presented here to describe the procedure. Over a 1 year period, the crowns have demonstrated good retention and esthetic results. How to cite this article: Mehra M, Grover R. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors. Int J Clin Pediatr Dent 2012;5(2):159-162. PMID:25206160

  19. Review: Resin Composite Filling

    Directory of Open Access Journals (Sweden)

    Desmond Ng

    2010-02-01

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

  20. Glass-ionomer Cements in Restorative Dentistry: A Critical Appraisal.

    Science.gov (United States)

    Almuhaiza, Mohammed

    2016-01-01

    Glass-ionomer cements (GICs) are mainstream restorative materials that are bioactive and have a wide range of uses, such as lining, bonding, sealing, luting or restoring a tooth. Although the major characteristics of GICs for the wider applications in dentistry are adhesion to tooth structure, fluoride releasing capacity and tooth-colored restorations, the sensitivity to moisture, inherent opacity, long-term wear and strength are not as adequate as desired. They have undergone remarkable changes in their composition, such as the addition of metallic ions or resin components to their composition, which contributed to improve their physical properties and diversified their use as a restorative material of great clinical applicability. The light-cured polymer reinforced materials appear to have substantial benefits, while retaining the advantages of fluoride release and adhesion. Further research should be directed towards improving the properties, such as strength and esthetics without altering its inherent qualities, such as adhesion and fluoride releasing capabilities. PMID:27340169

  1. Papahanaumokuakea - Laysan Island Restoration 2010

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Goal of the Laysan Island Restoration is to restore Laysan to a "Pristine" state which would require minimal monitoring and habitat for Endemic Endangered...

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

    Directory of Open Access Journals (Sweden)

    Alessandro Leite CAVALCANTI

    1999-04-01

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

  3. Early restorative rehabilitation of children and adolescents with amelogenesis imperfecta

    OpenAIRE

    Pousette Lundgren, Gunilla

    2015-01-01

    Amelogenesis imperfecta (AI) is a rare, genetically determined defect in enamel mineralization. Patients with (AI) can present with rapid tooth loss or fractures of enamel and dental sensitivity as well as alterations in enamel thickness, color, and shape. These factors may compromise esthetic appearance and masticatory function. Existing treatment recommendations suggest using resin composite restorations until adulthood, although such restorations have a limited longevity. The mai...

  4. Landscape context mediates avian habitat choice in tropical forest restoration.

    Directory of Open Access Journals (Sweden)

    J Leighton Reid

    Full Text Available Birds both promote and prosper from forest restoration. The ecosystem functions birds perform can increase the pace of forest regeneration and, correspondingly, increase the available habitat for birds and other forest-dependent species. The aim of this study was to learn how tropical forest restoration treatments interact with landscape tree cover to affect the structure and composition of a diverse bird assemblage. We sampled bird communities over two years in 13 restoration sites and two old-growth forests in southern Costa Rica. Restoration sites were established on degraded farmlands in a variety of landscape contexts, and each included a 0.25-ha plantation, island treatment (trees planted in patches, and unplanted control. We analyzed four attributes of bird communities including frugivore abundance, nectarivore abundance, migrant insectivore richness, and compositional similarity of bird communities in restoration plots to bird communities in old-growth forests. All four bird community variables were greater in plantations and/or islands than in control treatments. Frugivore and nectarivore abundance decreased with increasing tree cover in the landscape surrounding restoration plots, whereas compositional similarity to old-growth forests was greatest in plantations embedded in landscapes with high tree cover. Migrant insectivore richness was unaffected by landscape tree cover. Our results agree with previous studies showing that increasing levels of investment in active restoration are positively related to bird richness and abundance, but differences in the effects of landscape tree cover on foraging guilds and community composition suggest that trade-offs between biodiversity conservation and bird-mediated ecosystem functioning may be important for prioritizing restoration sites.

  5. Sealing occlusal caries lesions in adults referred for restorative treatment

    DEFF Research Database (Denmark)

    Bakhshandeh, Azam; Qvist, Vibeke; Ekstrand, Kim R

    2012-01-01

    treatment by senior lecturers at School of Dentistry, Copenhagen, Denmark were included. In case the patient had more than one occlusal caries lesion, randomization between sealing and restoration was made; otherwise, the lesion was sealed. In total, 60 resin sealants and 12 composite restorations were made....... Follow-up period was 25-38 months (mean¿=¿33 months). Data were analyzed using non-parametric statistics including kappa statistics. After 2-3 years, the dropout rate was 15%; two patients did not show up for control and nine previously sealed lesions were restored by the patients' general practitioners...

  6. Indirect porcelain veneer technique for restoring intrinsically stained teeth.

    Science.gov (United States)

    Cutbirth, S T

    1992-01-01

    Indirect porcelain veneers are often the ideal restoration for intrinsically stained teeth. This article details a step-by-step procedure for esthetically restoring discolored teeth. Porcelain laminate veneers are often indicated when teeth bleaching or direct composite bonding procedures cannot provide the desired esthetic result. Veneers are more appealing to many patients than full coverage crowns because of the more conservative tooth preparation required. If technique details are followed meticulously and cases are appropriately selected, porcelain veneers are not only durable but also promote marvelous gingival health and may be the most esthetic anterior dental restoration.

  7. Adaptive wiener image restoration kernel

    Science.gov (United States)

    Yuan, Ding

    2007-06-05

    A method and device for restoration of electro-optical image data using an adaptive Wiener filter begins with constructing imaging system Optical Transfer Function, and the Fourier Transformations of the noise and the image. A spatial representation of the imaged object is restored by spatial convolution of the image using a Wiener restoration kernel.

  8. River Restoration and Meanders

    OpenAIRE

    G. Mathias Kondolf

    2006-01-01

    Among the most visually striking river restoration projects are those that involve the creation of a new channel, often in a new alignment and generally with a form and dimensions that are different from those of the preproject channel. These channel reconstruction projects often have the objective of creating a stable, single-thread, meandering channel, even on rivers that were not historically meandering, on rivers whose sediment load and flow regime would not be consistent with such stable...

  9. Relativistic Linear Restoring Force

    Science.gov (United States)

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  10. Effects of restoration on instream bryophyte communities : Monitoring of two different restoration techniques in the Vindel River system

    OpenAIRE

    Sandberg, Lisa

    2015-01-01

    Ecological restoration is the practice of assisting the recovery of a degraded, damaged or destroyed ecosystem. The aim of this study was to analyse the effects of two different restoration techniques on instream bryophyte abundance, species richness and diversity as well as community composition, in streams channelized for timber-floating. Instream bryophytes were collected from 10 tributaries of the Vindel River in boreal northern Sweden, from five stream reaches each of channelized reaches...

  11. A priliminary study of rebuilding proximal contacts of class Ⅱ posterior composite restoration with dual-matrix placement technique%双步成形直接树脂充填法重建邻(牙合)面洞邻接关系初步研究

    Institute of Scientific and Technical Information of China (English)

    黎耀荣; 周禹雄; 刘瑜容

    2012-01-01

    AIM: To improve the technique for rebuilding proximal contacts of Class Ⅱ cavity restorations of posterior teeth by composite resin. METHODS: A clinical case with class Ⅱ cavity in posterior tooth was used. After cavity preparation, the cavity was translated into 36 resin models by salicon impressiion - resin irrigating - copying process. The models were divided into 3 groups . Group A, B and C were restored by Ivroy technique, palodent technique and a combination of Ivroy technique respectively. All cavities were restored by the same skilled operator. Independent assessment of the contact tightness and contour of each restoration was made after cavity filling. All data were analyzed using one-way ANOVA and LSD post-hoc tests (P <0.05) . RESULTS; Significant differences were found between 3 groups regarding proximal contact tightness and contour. CONCLUSION: Dual-matrix-placement technique plus Ivory technique and palodenl technique achieved the goal of rebuilding proximal contacts of posterior teeth by composite resin restoration.%目的:改良复杂条件下邻(牙合)面洞重建邻接关系的方法.方法:以制洞后临床邻(牙合)面病损为母本,经“硅橡胶印模-自凝树脂灌制”流程得36个带软性牙龈的树脂模型.模型平均分A、B、C3组,由同一高年资医师实施修复,A组以Ivory成形技术,B组以palodent技术树脂修复,C组采用改形后常规Ivory成形片修复颈1/3,palodent成形片修复(牙合)2/3,两步成形法树脂修复.术后评估修复区邻接紧密度和外形,评分采用单因素方差分析.结果:3组间修复质量评分均有显著统计学差异.结论:体外小规模模型研究条件下,基于Ivory加palodent技术分步双成形直接树脂充填法可重建邻(牙合)面洞邻接关系,比单独使用环周成形系统技术更佳的邻接触紧密度,比单独应用瓣状成形系统技术更合理的邻接区形态.

  12. A comparison between new dentinal adhesives (fifth generation and traditional varnish in microleakage reduction of amalgam restorations in primary teeth

    Directory of Open Access Journals (Sweden)

    Mortazavi M. Associate Professor

    2003-06-01

    Full Text Available Statement of Problem: Microleakage presents the major cause for restorations failure in the oral cavity resulting in postoperative sensitivity, pulp irritation and secondary caries formation."nAim: The aim of this study was to compare two dentinal adhesive systems of fifth generation and copalite varnish in reducing microleakage of amalgam restorations in primary teeth."nMaterials and Methods: In this in-vitro study, 100 class V amalgam restorations were prepared on the buccal or lingual surfaces of primary molar and canine teeth. Samples were randomly divided into four groups (25 samples each. No liner was used for the first group and the second group restorations were lined with copalite varnish. Two dentin adhesives, called Syntac C and Single Bond, were used for the third and fourth groups, respectively. At the next stage, the samples were immersed in 5% fuschin solution for 24 hours, then sectioned buccolingually, and examined under a stereomicroscope for microleakage evaluation."nResults: There was a significant difference between four groups statistically (PO.000I, Comparing"nfour groups, the first and fourth ones, demonstrated the most and the least microleakage, respectively."nConclusion: The present study showed that new dentinal adhesive systems caused microleakage"nreduction in amalgam restorations of primary teeth.

  13. Influência da contaminação com saliva na microinfiltração de restaurações de resina composta = The effect of saliva contamination on microleakage of composite restorative

    Directory of Open Access Journals (Sweden)

    Hasan, Nihad Hasan Musa

    2005-01-01

    Full Text Available O objetivo deste estudo foi avaliar a influência da contaminação com saliva na microinfiltração marginal de restaurações adesivas. Utilizaram-se 52 incisivos bovinos, sendo confeccionadas cavidades Classe V (vestibular/lingual, com margens em dentina e esmalte. As cavidades foram condicionadas com ácido fosfórico a 35% e divididas em quatro grupos. G1 – sem contaminação, os demais grupos foram contaminados com saliva fresca por 15s, sendo submetidos a diferentes tratamentos: G2 – secas com papel absorvente; G3 – lavadas com água; G4 – recondicionadas por 10s. O sistema adesivo (Single Bond/3M ESPE foi empregado segundo recomendações do fabricante e as cavidades restauradas com compósito (Filtek Z-250/3M ESPE. Após 24h as restaurações foram polidas e termocicladas (500 ciclos/5 e 55ºC/30s. Os dentes foram isolados, exceto as restaurações e a 1mm destas, imersos em fucsina básica a 1% (24h e lavados em água (24h. Foram seccionados e avaliados em lupa estereoscópica, utilizando-se escores predeterminados, por dois examinadores calibrados. Os valores obtidos foram submetidos à análise estatística (Kruskal-Wallis. A infiltração em dentina foi significantemente maior que aquela observada em esmalte (p < 0,05. Nas margens em dentina observou-se redução do selamento no G2 (p < 0,05. G3 e G4 restabeleceram o selamento a níveis similares ao controle (G1. Nas margens em esmalte G1 apresentou selamento similar ao G3 e ambos exibiram melhor selamento que G2 e G4 (p < 0,05, que foram similares. Conclusões: dentro das limitações do estudo, verificou-se que a contaminação com saliva após o condicionamento ácido interfere no selamento marginal de restaurações adesivas e os tratamentos propostos apresentaram resultados diversos

  14. Infiltração marginal em restaurações de resina composta com diferentes materiais adesivos intermediários = Marginal leakage in resin composite restorations lined with different adhesive materials

    Directory of Open Access Journals (Sweden)

    Moraes, Rafael Stanziona de

    2007-01-01

    Full Text Available Este estudo avaliou a capacidade de selamento de restaurações de resina composta com diferentes materiais adesivos intermediários. Cavidades Classe V padronizadas, com margens em esmalte e dentina/cemento, foram confeccionadas em incisivos bovinos. A resina de alto escoamento Fill Magic (Vigodent e o cimento ionomérico Vitremer (3M ESPE foram empregados como intermediários de restaurações com os compósitos Charisma e Solitaire (Heraeus Kulzer, formando 6 grupos (n = 14: [C1] – compósito microhíbrido Charisma; [C2] – Fill Magic + Charisma; [C3] – Vitremer + Charisma; [S1] – compósito condensável Solitaire; [S2] – Fill magic + Solitaire; [S3] – Vitremer + Solitaire. Após acabamento e polimento, as amostras foram armazenadas em solução fisiológica a 37ºC, por 30 dias, e então imersas em solução de fucsina básica a 0,5% por 24h. Os dentes foram longitudinalmente seccionados e a penetração do corante avaliada sob magnificância (40×, por dois examinadores, com escores padronizados. Os dados foram submetidos ao teste estatístico não-paramétrico de Kruskal-Wallis. Nas margens em esmalte, diferenças significativas foram verificadas apenas para a associação de intermediários à resina Solitaire, com os grupos S2 (p < 0,05 e S3 (p < 0,001 apresentando escores de infiltração significativamente maiores em relação aos demais. As margens em dentina/cemento apresentaram maior penetração em relação às margens em esmalte (p < 0,001. Apenas a associação do Vitremer às duas resinas melhorou o selamento deste substrato, com os grupos C3 (p < 0,001 e S3 (p < 0,05 apresentando os menores escores de infiltração

  15. 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.

  16. Fracture resistance of teeth restored with different resin-based restorative systems

    Directory of Open Access Journals (Sweden)

    Willian Yoshio Kikuti

    2012-06-01

    Full Text Available The aim of the present study was to evaluate the fracture resistance of teeth restored with resin composite. Forty-eight maxillary premolar teeth were chosen and randomly divided to six groups: G1 (control: sound teeth; G2: MOD preparation, unrestored; G3: MOD + Adper Single Bond 2/P60; G4: MOD + Adper Easy One/P60; G5: MOD + P90 restorative system; G6: MOD + Adper Easy One/P90 Bond/P90. Specimens were subjected to compressive axial loading (0.5 mm/min. Flexural strength and the modulus of elasticity were also tested (n = 7. The only statistical equivalence with sound teeth was noted for G3 (p < 0.05. Flexural strength and the modulus of elasticity varied among the composites tested (n = 10. The reestablishment of the resistance to fracture in premolars subjected to Class II MOD preparations is restorative-system-dependent. The silorane restorative system is not able to recover the resistance to fracture.

  17. Foraging and growth potential of juvenile Chinook Salmon after tidal restoration of a large river delta

    Science.gov (United States)

    David, Aaron T.; Ellings, Christopher; Woo, Isa; Simenstad, Charles A.; Takekawa, John Y.; Turner, Kelley L.; Smith, Ashley L.; Takekawa, Jean E.

    2014-01-01

    We evaluated whether restoring tidal flow to previously diked estuarine wetlands also restores foraging and growth opportunities for juvenile Chinook Salmon Oncorhynchus tshawytscha. Several studies have assessed the value of restored tidal wetlands for juvenile Pacific salmon Oncorhynchus spp., but few have used integrative measures of salmon performance, such as habitat-specific growth potential, to evaluate restoration. Our study took place in the Nisqually River delta, Washington, where recent dike removals restored tidal flow to 364 ha of marsh—the largest tidal marsh restoration project in the northwestern contiguous United States. We sampled fish assemblages, water temperatures, and juvenile Chinook Salmon diet composition and consumption rates in two restored and two reference tidal channels during a 3-year period after restoration; these data were used as inputs to a bioenergetics model to compare Chinook Salmon foraging performance and growth potential between the restored and reference channels. We found that foraging performance and growth potential of juvenile Chinook Salmon were similar between restored and reference tidal channels. However, Chinook Salmon densities were significantly lower in the restored channels than in the reference channels, and growth potential was more variable in the restored channels due to their more variable and warmer (2°C) water temperatures. These results indicate that some—but not all—ecosystem attributes that are important for juvenile Pacific salmon can recover rapidly after large-scale tidal marsh restoration.

  18. River Restoration and Meanders

    Directory of Open Access Journals (Sweden)

    G. Mathias Kondolf

    2006-12-01

    Full Text Available Among the most visually striking river restoration projects are those that involve the creation of a new channel, often in a new alignment and generally with a form and dimensions that are different from those of the preproject channel. These channel reconstruction projects often have the objective of creating a stable, single-thread, meandering channel, even on rivers that were not historically meandering, on rivers whose sediment load and flow regime would not be consistent with such stable channels, or on already sinuous channels whose bends are not symmetrical. Such meandering channels are often specified by the Rosgen classification system, a popular restoration design approach. Although most projects of this type have not been subject to objective evaluation, completed postproject appraisals show that many of these projects failed within months or years of construction. Despite its, at best, mixed results, this classification and form-based approach continues to be popular because it is easy to apply, because it is accessible to those without formal training in fluvial geomorphology, and probably because it satisfies a deep-seated, although unrecognized, cultural preference for single-thread meandering channels. This preference is consistent with 18th-century English landscape theories, which held the serpentine form to be ideal and led to widespread construction of meandering channels on the country estates of the era. The preference for stability in restored channels seems to be widely accepted by practitioners and funders despite the fact that it is antithetical to research showing that dynamically migrating channels have the greatest ecological richness.

  19. Skjern River Restoration Counterfactual

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    heritage. While the meanders of the Skjern River were reconstructed according to its assumed course in 1870s, the embanked canal, which was the main feature and symbol of a comprehensive cultivation project from the 1960s, was deconstructed and reduced to incomprehensible traces of the past. Not only did...... history and more openness towards constant change. In this approach the idea of palimpsest as metaphor for the cultural landscape plays an important role. Rather than being an obstacle for the restoration of nature, the historical layer following the comprehensive cultivation project from the 1960s...

  20. Wetland Microbial Community Response to Restoration

    Science.gov (United States)

    Theroux, S.; Hartman, W.; Tringe, S. G.

    2015-12-01

    Wetland restoration has been proposed as a potential long-term carbon storage solution, with a goal of engineering geochemical dynamics to accelerate peat accretion and encourage greenhouse gas (GHG) sequestration. However, wetland microbial community composition and metabolic rates are poorly understood and their predicted response to wetland restoration is a veritable unknown. In an effort to better understand the underlying factors that shape the balance of carbon flux in wetland soils, we targeted the microbial communities along a salinity gradient ranging from freshwater tidal marshes to hypersaline ponds in the San Francisco Bay-Delta region. Using 16S rRNA gene sequencing and shotgun metagenomics, coupled with greenhouse gas measurements, we sampled sixteen sites capturing a range in salinity and restoration status. Seawater delivers sulfate to wetland ecosystems, encouraging sulfate reduction and discouraging methane production. As expected, we observed the highest rates of methane production in the freshwater wetlands. Recently restored wetlands had significantly higher rates of methane production compared to their historic counterparts that could be attributed to variations in trace metal and organic carbon content in younger wetlands. In contrast, our sequencing results revealed an almost immediate return of the indigenous microbial communities following seasonal flooding and full tidal restoration in saline and hypersaline wetlands and managed ponds. Notably, we found elevated methane production rates in hypersaline ponds, the result of methylotrophic methane production confirmed by sequence data and lab incubations. Our study links belowground microbial communities and their aboveground greenhouse gas production and highlights the inherent complexity in predicting wetland microbial response in the face of both natural and unnatural disturbances.

  1. Discoloration of Provisional Restorations after Oral Rinses

    Science.gov (United States)

    Turgut, Sedanur; Bagis, Bora; Ayaz, Elif Aydogan; Ulusoy, Kıvanç Utku; Altintas, Subutay Han; Korkmaz, Fatih Mehmet; Bagis, Nilsun

    2013-01-01

    Purpose: Oral rinses are widely used to promote periodontal health with provisional restorations during the interim period. The aim of this study was to compare the discoloration of provisional restoration materials with different oral rinses. Material and Methods: A total of 140 disc-shaped specimens (shade A2) (10 mm x 2 mm) were prepared from one PMMA-based (TemDent Classic®) and three different bis-acrylic-based (Protemp II®, Luxatemp® and Fill-In®) provisional restoration materials (n=7). The color values (L*, a*, and b*) of each specimen were measured before and after exposure with a colorimeter, and the color changes (∆E) were calculated according to the CIE L*a*b* system. The specimens were immersed in each of the 4 oral rinses (alcohol-containing mouthwash, chlorhexidine, benzydamine HCl, benzydamine HCl and chlorhexidine) twice a day for 2 minutes. After 2 minutes of immersion in the oral rinses, the specimens were immersed in artificial saliva. The specimens were exposed to the oral rinses and the artificial saliva for 3 weeks. Two-way ANOVA, the Bonferroni test and the paired sample t-test were used for statistical analyses (p0.05). The lowest color change was observed in PMMA-based Temdent in all oral rinses (pbis-acryl composites after immersion in saliva or the mixture of benzydamine HCl and chlorhexidine and the alcohol-containing mouthwash for 3 weeks (p>0.05). After immersion in chlorhexidine, the color change values of Protemp II and Fill-in showed significant differences (p=0.018). Protemp II also showed less discoloration than the other bis-acryl composites, and this color change was statistically significant (p materials for provisional restorations appears to be more effective. PMID:24046524

  2. Restoring proximal caries lesions conservatively with tunnel restorations

    OpenAIRE

    Chu CH; Mei ML; Cheung C; Nalliah RP

    2013-01-01

    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 pre...

  3. Restoring proximal caries lesions conservatively with tunnel restorations

    OpenAIRE

    Chu, Chun-Hung

    2013-01-01

    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 slo...

  4. Long Term Positive Effect of Grassland Restoration on Plant Diversity - Success or Not?

    Science.gov (United States)

    Waldén, Emelie; Lindborg, Regina

    2016-01-01

    Restoration is important for biodiversity conservation worldwide, but surprisingly little is known about its efficiency in a long-term perspective. In this study, we re-examined Swedish semi-natural grasslands 12-20 years after the restoration, by comparing field inventories of vascular plant species diversity made in 2001 with follow-up inventories in 2012. We also analysed restoration effect in relation to six environmental factors and used continuously managed semi-natural grasslands as references of desired state after restoration. We found that total species richness increased over time but not to reference levels, while there were no significant changes in species density or number of grassland specialists. However, the overall species composition in the restored sites, as well as grassland specialist composition, now largely resembled reference conditions. Fertilisation and time between abandonment and restoration were the only environmental variables that affected total species composition change, while site area affected change in grassland specialist composition. Our results show that restoration of semi-natural grasslands can contribute to conservation of semi-natural habitats and their associated biodiversity. Yet, due to the vague restoration goals for these sites, it is difficult to evaluate the restoration success, which emphasise the general need for clear and measurable goals. PMID:27196748

  5. Evaluation of the dental structure loss produced during maintenance and replacement of occlusal amalgam restorations

    Directory of Open Access Journals (Sweden)

    Fernanda Sardenberg

    2008-09-01

    Full Text Available The aim of this in vitro study was to evaluate four different approaches to the decision of changing or not defective amalgam restorations in first primary molar teeth concerning the loss of dental structure. Ditched amalgam restorations (n = 11 were submitted to four different treatments, as follows: Control group - polishing and finishing of the restorations were carried out; Amalgam group - the ditched amalgam restorations were replaced by new amalgam restorations; Composite resin group - the initial amalgam restorations were replaced by composite resin restorations; Flowable resin group - the ditching around the amalgam restorations was filled with flowable resin. Images of the sectioned teeth were made and the area of the cavities before and after the procedures was determined by image analysis software to assess structural loss. The data were submitted to ANOVA complemented by the Student Newman Keuls test (p < 0.05. The cavities in all the groups presented significantly greater areas after the procedures. However, the amalgam group showed more substantial dental loss. The other three groups presented no statistically significant difference in dental structure loss after the re-treatments. Thus, replacing ditched amalgam restorations by other similar restorations resulted in a significant dental structure loss while maintaining them or replacing them by resin restorations did not result in significant loss.

  6. Reparative dentistry or restorative dentistry?

    Science.gov (United States)

    Small, Bruce W

    2008-01-01

    The real definition of restorative dentistry is found in the heart and hands of each individual restorative dentist. His or her training, continuing dental education, mentors, needs (financial and emotional), and style of practice all help to develop a philosophy of dental practice that affects daily restorative decisions. Depending on the factors described above, the decision to repair a tooth or change the environment and restore the tooth to a different shape, size, or color also may change. In recent years, patients' esthetic desires have become more of a factor than they were in previous decades. There are no exact written-tn-stone definitions of restorative dentistry, since the answers are operator-dependent and can vary. This column is meant to be food for thought and perhaps inspire discussion when dentists assemble for meetings or study clubs with the goal of delivering longer-lasting dentistry through a restorative dental practice. PMID:18348367

  7. Archived film analysis and restoration

    OpenAIRE

    Rares, A.

    2004-01-01

    The progressive degradation of current film archives poses a serious threat to the preservation of our cultural and technical heritage. Digitization and digital restoration are currently the most viable solutions for the long term preservation and high quality restoration of filmed material. They also open the path for more effective search, reuse and distribution of the archived content. This thesis covers various aspects of digital restoration applied to archived film. The main focus here l...

  8. Composite inlays: a systematic review.

    Science.gov (United States)

    Grivas, E; Roudsari, R V; Satterthwaite, J D

    2014-09-01

    The purpose of this study is to review the available literature related to composite inlays. Electronic databases published up to November 2013 were searched. Studies that evaluate composite resin inlays for the restoration of posterior teeth were selected. The studies should compare composite inlays against gold inlays, ceramic inlays and direct composite fillings regarding longevity, aesthetic quality and postoperative sensitivity or comparing the clinical effectiveness of them on premolars versus molars or on 1-2 surface preparations versus multi-surface preparations. Despite the heterogeneity of the available clinical trials composite inlays seem to be an effective method for the restoration of posterior teeth. PMID:25831713

  9. Composite inlays: a systematic review.

    Science.gov (United States)

    Grivas, E; Roudsari, R V; Satterthwaite, J D

    2014-09-01

    The purpose of this study is to review the available literature related to composite inlays. Electronic databases published up to November 2013 were searched. Studies that evaluate composite resin inlays for the restoration of posterior teeth were selected. The studies should compare composite inlays against gold inlays, ceramic inlays and direct composite fillings regarding longevity, aesthetic quality and postoperative sensitivity or comparing the clinical effectiveness of them on premolars versus molars or on 1-2 surface preparations versus multi-surface preparations. Despite the heterogeneity of the available clinical trials composite inlays seem to be an effective method for the restoration of posterior teeth.

  10. Technologies for lake restoration

    Directory of Open Access Journals (Sweden)

    Helmut KLAPPER

    2003-09-01

    Full Text Available Lakes are suffering from different stress factors and need to be restored using different approaches. The eutrophication remains as the main water quality management problem for inland waters: both lakes and reservoirs. The way to curb the degradation is to stop the nutrient sources and to accelerate the restoration with help of in-lake technologies. Especially lakes with a long retention time need (eco- technological help to decrease the nutrient content in the free water. The microbial and other organic matter from sewage and other autochthonous biomasses, causes oxygen depletion, which has many adverse effects. In less developed countries big reservoirs function as sewage treatment plants. Natural aeration solves problems only partly and many pollutants tend to accumulate in the sediments. The acidification by acid rain and by pyrite oxidation has to be controlled by acid neutralizing technologies. Addition of alkaline chemicals is useful only for soft waters, and technologies for (microbial alkalinization of very acidic hardwater mining lakes are in development. The corrective measures differ from those in use for eutrophication control. The salinization and water shortage mostly occurs if more water is used than available. L. Aral, L. Tschad, the Dead Sea or L. Nasser belong to waters with most severe environmental problems on a global scale. Their hydrologic regime needs to be evaluated. The inflow of salt water at the bottom of some mining lakes adds to stability of stratification, and thus accumulation of hydrogen sulphide in the monimolimnion of the meromictic lakes. Destratification, which is the most used technology, is only restricted applicable because of the dangerous concentrations of the byproducts of biological degradation. The contamination of lakes with hazardous substances from industry and agriculture require different restoration technologies, including subhydric isolation and storage, addition of nutrients for better self

  11. Minimally invasive restorative dentistry: a biomimetic approach.

    Science.gov (United States)

    Malterud, Mark I

    2006-08-01

    When providing dental treatment for a given patient, the practitioner should use a minimally invasive technique that conserves sound tooth structure as a clinical imperative. Biomimetics is a tenet that guides the author's practice and is generally described as the mimicking of natural life. This can be accomplished in many cases using contemporary composite resins and adhesive dental procedures. Both provide clinical benefits and support the biomimetic philosophy for treatment. This article illustrates a minimally invasive approach for the restoration of carious cervical defects created by poor hygiene exacerbated by the presence of orthodontic brackets.

  12. Indirect resin composites

    Directory of Open Access Journals (Sweden)

    Nandini Suresh

    2010-01-01

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

  13. Restoring medical professionalism.

    Science.gov (United States)

    Bernat, James L

    2012-08-21

    The essence of medical professionalism is placing dedication to the welfare of patients above physicians' personal or proprietary interests. Medicine has become deprofessionalized as a consequence of socioeconomic factors leading to increasing commercialization and perverse financial incentives converting it into a business, the presence of unmanaged conflicts of interest, challenges to medical authority by insurance companies and the consumerism movement, and by gradual changes in the attitudes of physicians. Organized medicine has responded by making explicit its standards of professionalism and its dedication to preserving them. Medical educators have studied the means to develop professional attitudes and behaviors among medical students and residents. Modeling the characteristics of professional behavior by virtuous physicians remains the most effective method to instill professional behaviors in trainees. Restoring professionalism may be abetted by changes in physicians' financial incentives through innovative models of health care delivery, by physicians reducing their conflicts of interest, and by medical societies rejecting a guild identity. PMID:22915177

  14. 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. PMID:18833762

  15. 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.

  16. Peatland restoration in Canada by the sphagnum moss layer transfer method

    Energy Technology Data Exchange (ETDEWEB)

    Rochefort, L.; Boismenu, C. [Laval Univ., Quebec City, PQ (Canada). Dept. de Phytologie, Peatland Ecology and Research Group; Quinty, F. [SNC-Lavalin, Montreal, PQ (Canada)

    2009-04-01

    This article described a peatland restoration approach that has received international recognition for restoring the ecological functions of cutover sphagnum dominated peatlands. The Peatland Ecology Research Group (PERG) conducted a long-term study at the Bois-des-Bel (BDB) peatland site in Quebec to restore plant composition to a peat accumulating ecosystem. The sphagnum moss layer transfer restoration method includes 5 obligatory steps and one optional. These include planning; surface preparation; plant collection and spreading; straw mulch spreading; blocking drainage ditches; and fertilization if needed. Variable moisture conditions throughout the restoration site contribute to the spatial variability in the development of the sphagnum layer. The site has been monitored each year since its restoration. sphagnum cover reached 60 per cent in the restored zone in 2005, a value close to the range of sphagnum cover found in natural sites. In addition, a new moss layer has developed with an average of 25 cm in thickness. 27 refs., 4 figs.

  17. Leaf litter arthropod responses to tropical forest restoration.

    Science.gov (United States)

    Cole, Rebecca J; Holl, Karen D; Zahawi, Rakan A; Wickey, Philipp; Townsend, Alan R

    2016-08-01

    Soil and litter arthropods represent a large proportion of tropical biodiversity and perform important ecosystem functions, but little is known about the efficacy of different tropical forest restoration strategies in facilitating their recovery in degraded habitats. We sampled arthropods in four 7- to 8-year-old restoration treatments and in nearby reference forests. Sampling was conducted during the wet and dry seasons using extractions from litter and pitfall samples. Restoration treatments were replicated in 50 × 50-m plots in four former pasture sites in southern Costa Rica: plantation - trees planted throughout the plot; applied nucleation/islands - trees planted in patches of different sizes; and natural regeneration - no tree planting. Arthropod abundance, measures of richness and diversity, and a number of functional groups were greater in the island treatment than in natural regeneration or plantation treatments and, in many cases, were similar to reference forest. Litter and pitfall morphospecies and functional group composition in all three restoration treatments were significantly different than reference sites, but island and plantation treatments showed more recovery than natural regeneration. Abundance and functional group diversity showed a much greater degree of recovery than community composition. Synthesis and applications: The less resource-intensive restoration strategy of planting tree islands was more effective than tree plantations in restoring arthropod abundance, richness, and functional diversity. None of the restoration strategies, however, resulted in similar community composition as reference forest after 8 years of recovery, highlighting the slow rate of recovery of arthropod communities after disturbance, and underscoring the importance of conservation of remnant forests in fragmented landscapes. PMID:27551373

  18. 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.

  19. Evaluation of fracture resistance of endodontically treated teeth restored with prefabricated posts and composites with varying quantities of remaining coronal tooth structure Avaliação da resistência à fratura de dentes tratados endodonticamente restaurados com pinos pré-fabricados e resinas compostas variando o remanescente dentário coronal

    Directory of Open Access Journals (Sweden)

    Murilo Pereira de Melo

    2005-06-01

    Full Text Available OBJECTIVES: The aim of this study was to evaluate the influence of remaining coronal tooth structure on endodontically treated teeth restored with prefabricated posts and two different composites for core build-up: dual-cured resin (Enforce Core and light-cured resin (Z-250. METHODS: Fourty freshly extracted canines were endodontically treated and divided into four groups: Group I - teeth with 3mm remaining coronal structure, restored with Enforce Core; Group II - teeth with 3mm remaining coronal structure, restored with Z-250; Group III - teeth with no remaining coronal structure, restored with Enforce; Group IV - teeth with no remaining coronal structure, restored with Z-250. After restoration, the teeth were embedded in acrylic resin and the fracture resistance was measured on a universal testing machine at 45 degrees to the long axis of the tooth until failure. RESULTS: Data were analyzed by two-way analysis of variance, which showed significant differences between groups (p=0.00. The Tukey test did not show significant differences between specimens with and without remaining coronal structure. Conversely, significant difference was observed between groups with different core build-up. The highest values of fracture resistance were found in the group restored with light-cured resin. SIGNIFICANCE: The remaining coronal tooth structure did not influence the resistance of endodontically treated teeth; however, the change of core build-up was able to modify this resistence.O objetivo desta pesquisa foi avaliar a influência do remanescente dentário coronal de dentes tratados endodonticamente, restaurados com pinos pré-fabricados e duas resinas como núcleos de preenchimento, uma de presa dual (Enforce Core e outra fotopolimerizável (Z-250. Foram utilizados 40 caninos superiores humanos extraídos, divididos em quatro grupos de 10 espécimes: Grupo l - com remanescente dentário coronal de 3mm e restaurados com Enforce Core; Grupo ll - com

  20. Restoration treatments in urban park forests drive long-term changes in vegetation trajectories.

    Science.gov (United States)

    Johnson, Lea R; Handel, Steven N

    2016-04-01

    Municipalities are turning to ecological restoration of urban forests as a measure to improve air quality, ameliorate urban heat island effects, improve storm water infiltration, and provide other social and ecological benefits. However, community dynamics following urban forest restoration treatments are poorly documented. This study examines the long-term effects of ecological restoration undertaken in New York City, New York, USA, to restore native forest in urban park natural areas invaded by woody non-native plants that are regional problems. In 2009 and 2010, we sampled vegetation in 30 invaded sites in three large public parks that were restored 1988-1993, and 30 sites in three large parks that were similarly invaded but had not been restored. Data from these matched plots reveal that the restoration treatment achieved its central goals. After 15-20 years, invasive species removal followed by native tree planting resulted in persistent structural and compositional shifts, significantly lower invasive species abundance, a more complex forest structure, and greater native tree recruitment. Together, these findings indicate that successional trajectories of vegetation dynamics have diverged between restored forests and invaded forests that were not restored. In addition, the data suggest that future composition of these urban forest patches will be novel assemblages. Restored and untreated sites shared a suite of shade-intolerant, quickly-growing tree species that colonize disturbed sites, indicating that restoration treatments created sites hospitable for germination and growth of species adapted to high light conditions and disturbed soils. These findings yield an urban perspective on the use of succession theory in ecological restoration. Models of ecological restoration developed in more pristine environments must be modified for use in cities. By anticipating both urban disturbances and ecological succession, management of urban forest patches can be

  1. Restorative Justice in School Communities.

    Science.gov (United States)

    Karp, David R.; Breslin, Beau

    2001-01-01

    Explores the recent implementation of restorative justice practices in Minnesota, Colorado, and Pennsylvania school communities, examining how their approaches can address substance abuse problems and offer alternatives to zero-tolerance policies. The three programs are committed to the idea that restoration is a more appropriate educational tool…

  2. SOCIAL WELFARE AND RESTORATIVE JUSTICE

    Directory of Open Access Journals (Sweden)

    Darrell Fox

    2009-09-01

    Full Text Available This paper explores the links and connections between social work and restorative justice. After a brief description of social work, restorative justice and family group conferencing, I will explore some the complementary theoretical links and practice applications, critically examining the potential implications and opportunities for social work practitioners and academics in relation to practice.

  3. Archived film analysis and restoration

    NARCIS (Netherlands)

    Rares, A.

    2004-01-01

    The progressive degradation of current film archives poses a serious threat to the preservation of our cultural and technical heritage. Digitization and digital restoration are currently the most viable solutions for the long term preservation and high quality restoration of filmed material. They al

  4. Occlusal wear of provisional implant-supported restorations

    NARCIS (Netherlands)

    Santing, Hendrik J.; Kleverlaan, Cornelis J.; Werner, Arie; Feilzer, Albert J.; Raghoebar, Gerry M.; Meijer, Henny J. A.

    2015-01-01

    BACKGROUND: Implant-supported provisional restorations should be resistant to occlusal wear. PURPOSE: The purpose of this laboratory study was to evaluate three-body wear of three indirect laboratory composite resins, five chair side bis-acryl resin-based materials, and two chair side methacrylate-b

  5. Occlusal wear of provisional implant-supported restorations

    NARCIS (Netherlands)

    H.J. Santing; C.J. Kleverlaan; A. Werner; A.J. Feilzer; G.M. Raghoebar; H.J.A. Meijer

    2015-01-01

    Background Implant-supported provisional restorations should be resistant to occlusal wear. Purpose The purpose of this laboratory study was to evaluate three-body wear of three indirect laboratory composite resins, five chair side bis-acryl resin-based materials, and two chair side methacrylate-bas

  6. Restoration of decayed primary incisors using strip crowns.

    Science.gov (United States)

    Pollard, M A; Curzon, J A; Fenlon, W L

    1991-05-01

    Caries of the primary incisors is a common problem that can be arrested if recognized early enough. However, the arrested decay is unsightly. Celluloid 'strip' crown forms, used with composite resin, now allow the restoration of even the most badly decayed primary incisors. The authors describe this quick and efficient technique. PMID:1884866

  7. [Cast partial restorations: outdated!

    NARCIS (Netherlands)

    Creugers, N.H.J.

    2004-01-01

    The decision to apply a certain therapy is the outcome of a process in which the advantages and disadvantages of this therapy are weighed and compared to alternative therapies. Key words in this process are effectiveness and efficiency. Comparison of inlays and onlays with direct resin composite res

  8. An esthetic restorative technique for use during the stabilization period after vertical root extrusion.

    Science.gov (United States)

    Hartwell, G R; Cecic, P A

    1983-07-01

    A case report illustrates an esthetic temporary restorative technique for use during the stabilization period after vertical root extrusion. A polycarbonate crown was adapted to the stabilized root and anchor system with acid-etch composite resin material. This restoration withstood a five-month stabilization period and provided both function and a good esthetic appearance.

  9. Effects of landscape gradients on wetland vegetation communities: information for large-scale restoration

    OpenAIRE

    Zweig, Christa L.; Kitchens, Wiley M.

    2008-01-01

    Projects of the scope of the restoration of the Florida Everglades require substantial information regarding ecological mechanisms, and these are often poorly understood. We provide critical base knowledge for Everglades restoration by characterizing the existing vegetation communities of an Everglades remnant, describing how present and historic hydrology affect wetland vegetation community composition, and documenting change from communities described in previous studies. Vegeta...

  10. Belowground-system development of VA mycorrhiza in a restored tallgrass prairie community

    Energy Technology Data Exchange (ETDEWEB)

    Cook, B.D.; Jastrow, J.D.; Miller, R.M.; McGraw, A.C.

    1987-01-01

    This study was conducted to determine the relationship between root and VA mycorrhizal fungus development in a tallgrass prairie restoration chronosequence. Emphasis is placed on characterizing the relationship of root length, colonized root length, and percentage of root length occupied by the mycorrhizal fungus by differing root size classes. Mycorrhizal fungus composition and populations along the restoration chronosequence was determined. 3 refs., 1 fig.

  11. The influence of different restorative materials on secondary caries development in situ

    NARCIS (Netherlands)

    Sande, F.H. van de; Opdam, N.J.; Truin, G.J.; Bronkhorst, E.M.; Soet, J.J. de; Cenci, M.S.; Huysmans, M.C.

    2014-01-01

    OBJECTIVES: The effect of direct restorative materials on caries lesion formation was investigated with an 8-week in situ study with split-mouth design, testing the hypothesis that no difference in mineral loss next to a restoration would be found between different composite-based-materials and amal

  12. The influence of different restorative materials on secondary caries development in situ

    NARCIS (Netherlands)

    F.H. van der Sande; N.J.M. Opdam; G.J. Truin; E.M. Bronkhorst; J.J. de Soet; M.S. Cenci; M.C. Huysmans

    2014-01-01

    Objectives The effect of direct restorative materials on caries lesion formation was investigated with an 8-week in situ study with split-mouth design, testing the hypothesis that no difference in mineral loss next to a restoration would be found between different composite-based-materials and amalg

  13. Composite resin in medicine and dentistry.

    Science.gov (United States)

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

    2005-01-01

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

  14. Butterfly responses to prairie restoration through fire and grazing

    Science.gov (United States)

    Vogel, Jennifer A.; Debinski, Diane M.; Koford, Rolf R.; Miller, J.R.

    2007-01-01

    The development of land for modern agriculture has resulted in losses of native prairie habitat. The small, isolated patches of prairie habitat that remain are threatened by fire suppression, overgrazing, and invasion by non-native species. We evaluated the effects of three restoration practices (grazing only, burning only, and burning and grazing) on the vegetation characteristics and butterfly communities of remnant prairies. Total butterfly abundance was highest on prairies that were managed with burning and grazing and lowest on those that were only burned. Butterfly species richness did not differ among any of the restoration practices. Butterfly species diversity was highest on sites that were only burned. Responses of individual butterfly species to restoration practices were highly variable. In the best predictive regression model, total butterfly abundance was negatively associated with the percent cover of bare ground and positively associated with the percent cover of forbs. Canonical correspondence analysis revealed that sites with burned only and grazed only practices could be separated based on their butterfly community composition. Butterfly communities in each of the three restoration practices are equally species rich but different practices yield compositionally different butterfly communities. Because of this variation in butterfly species responses to different restoration practices, there is no single practice that will benefit all species or even all species within habitat-specialist or habitat-generalist habitat guilds. ?? 2007 Elsevier Ltd. All rights reserved.

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

    Institute of Scientific and Technical Information of China (English)

    戴晓枫

    2012-01-01

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