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Sample records for class-v composite restorations

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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...

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

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

    International Nuclear Information System (INIS)

    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

  14. 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

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

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    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

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

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    Pulga, Neusa Vieira Galvao

    2001-07-01

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

  17. 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

  18. Effect of Air Abrasion Preconditioning on Microleakage in Class V Restorations Under Cyclic Loading: An In-vitro Study

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    Kumar, Umesh; Dharmani, Charan Kamal Kaur; Singh, Shamsher; Logani, Ajay; Shah, Naseem

    2014-01-01

    Background: Microleakage in class V Glass Ionomer Cement(GIC) or composite restorations at enamel or cementum margins has been cited as a reason for their failure. Air abrasion has been used to precondition tooth surface for increasing retention of such restorations. This study is done to evaluate the effect of preconditioning with air abrasion on microleakage in class V GIC and composite restorations.

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

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    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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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...

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

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    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.

  6. 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

  7. 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

  8. 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

  9. 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

    OpenAIRE

    Zanata, Régia Luzia; PALMA Regina Guenka; Navarro, Maria Fidela de Lima

    1998-01-01

    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 componente...

  10. 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

  11. 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

  12. Surface topography of composite restorative materials following ultrasonic scaling and its Impact on bacterial plaque accumulation. An in-vitro SEM study

    OpenAIRE

    Hossam, A. Eid; Rafi, A. Togoo; Ahmed, A Saleh; Sumanth, Phani CR

    2013-01-01

    Background: This is an in vitro study to investigate the effects of ultrasonic scaling on the surface roughness and quantitative bacterial count on four different types of commonly used composite restorative materials for class V cavities.

  13. Effects of cavity configuration on composite restoration.

    Science.gov (United States)

    Choi, Kyoung-Kyu; Ryu, Gil-Joo; Choi, Seung-Mo; Lee, Min-Jo; Park, Sang-Jin; Ferracane, Jack L

    2004-01-01

    This study evaluated the effects of various cavity configurations on the bond strength, microleakage, flexural strength and elastic modulus of a hybrid (Clearfil AP-X) and a microhybrid (Esthet-X) composite restorative. After the specimens were made with C-factors of less than 1, 2.4 and 3.4, flexural strength and elastic modulus were evaluated in three-point bending using a mechanical testing machine. Fragments of the fractured specimens were selected randomly and the fracture surfaces were examined in SEM. To evaluate the microtensile bond strength and microleakage of composite restorations in bovine cavities, C-factors (ratio of bonded to non-bonded cavity surface) were controlled as 1.0, 2.3, 3.0 and 3.7. All specimens were stored in distilled water at 37 degrees C for 24 hours and tested in a universal testing machine (EZ Test, Shimadzu, Japan). For the microleakage test, teeth with restorations were stained with silver nitrate and examined by two examiners under a stereomicroscope at 40x magnification. The hybrid composite showed higher mechanical properties than the microhybrid composite. The flexural strength and elastic modulus of both composites decreased when polymerized under greater constraint, that is, with increasing C-factor. Mean microtensile bond strength to dentin was also decreased with increasing C-factor for both types of composites. Microleakage scores for the hybrid composite restorations were generally higher than the microhybrid composite. PMID:15279488

  14. Effect of Chlorhexidine on Microleakage of Composite Restorations

    Directory of Open Access Journals (Sweden)

    F. Darabi

    2009-03-01

    Full Text Available Objective: The aim of this study was to evaluate the effect of concepsis (a chlorhexidine gluconate based cavity disinfectant application on composite restorations micro leakage,using two adhesive systems: Excite and Adhese.Materials and Methods: In this interventional experimental study, class V cavities were prepared on buccal surfaces of seventy-two extracted bovine incisors. The specimens were randomly divided into 6 groups (n=12: A1: Acid Eching (AE, Excite; A2: AE, Concepsis,blot drying, Excite; A3: AE, Concepsis, water rinsing, Excite; B1: AE (only enamel margin, Adhese; B2: AE (only enamel margin, Concepsis, blot drying, Adhese; B3: AE (only enamel margin, Concepsis, water ringsing, Adhese. Afterwards, the cavities wererestored with tetric Ceram composite, thermo-cycled (5 to 50°C, dwell time: 30s, 1000 cycles,, immersed in 0.5% methylen blue for 24 hours and the dye penetration was evaluated and scored on a scale on 0 to 4 under stereomicroscope (×30. The data were analyzedusing Kruskal-Wallis and Multiple Comparison tests.Results: The only statistically significant difference was found between groups B1 and B2 at both occlusal and gingival margins. (P<0.05Conclusion: Rinsing off the cavity disinfectant (Concepsis before the bonding procedure does not affect the seal at the resin-tooth interface when using either of the adhesive systems;however, the sealing ability of Adhese seems to be inhibited by the remnants of the disinfecting agent.

  15. Effects of Sodium hypochlorite on the microleakage of composite restorations

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    Arami S.

    2004-07-01

    Full Text Available Statement of Problem: Considering that the role of collagen fibers in dentin adhesion has not been thoroughly established yet, the removal of exposed collagen fibers with a deproteinization agent such as sodium hypochlorite following etching may facilitate access of adhesive resins to a substrate that is more penetrable and less sensitive to water content which in turn would lead to a more durable bonding system. Furthermore, due to sodium hypochlorite clinical application as a cleanser or canal irrigator, its effects on the surface before etching may influence adhesive bonding strength. Purpose: The goal of this study was to evaluate the effects of a two-minute 5.25% NaOCL application on composite restorations microleakage, using two different adhesive systems. Materials and Methods: In this interventional experimental study, on seventy-two extracted boving incisors class V cavities were prepared on dentinal surfaces. The specimens were then randomly divided into six equal groups: A1 Acid etch (AE dentin bonding Scontchbond Multipurpose Plus (SBMBP, A2 AE/ dentin bonding One Step (OS, B1 NaOCL/ AE/SBMPp, B2 NaOCL/AE/OS, C1 AE/NaOCL/SBMPp, C2 AE/NaOCL/OS. After bonding procedures according to the manufacturer’s instructions, cavities were restored using Z100 composite. Then, the specimens were thermocycled for 500 times in water baths of 5 and 55C. After thermocycling, the specimens were immersed in a 0.2% solution of basic fuchsin for 24 hours. A buccolingual section at the center of each restoration was obtained and examined with a stereomicroscope to evaluate color penetration into cavities. The data were subjected to two-way variance analysis. Results: The microleakage of group B was significantly less than those of A and C (P<0.001. No significant difference was found between groups A and C (P=0.73. There were also no significant differences within groups A, B and C (P=0.852. No interaction was observered between dentin bondings and

  16. DIRECT PERMANENT RESTORATIVES - AMALGAM VS COMPOSITE

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    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

  17. Assessment of the Quality of Composite Resin Restorations

    OpenAIRE

    Z. A. Ijaimi; N. H. Abu-Bakr; Ibrahim, Y. E.

    2015-01-01

    Purpose: To evaluate the quality of the composite restorations. Material and Methods: A total of 246 composite restorations in 125 patients attending the Conservative Dentistry Clinics at the Faculty of Dentistry, University of Khartoum were examined. Both anterior and posterior composite restorations were included. California Dental Association Quality Evaluation System was used for the evaluation. Results: Fifty two percent of all restorations were found to be satisfactory, while the remain...

  18. 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

  19. 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

  20. 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

  1. 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.

  2. Mini fiberglass post for composite resin restorations: A clinical report.

    Science.gov (United States)

    Morgan, Luís Fernando Dos Santos Alves; Martins, Adriana Vieira; Albuquerque, Rodrigo de Castro; Silveira, Rodrigo Richard; Silva, Nelson Renato França Alves; Moreira, Allysson Nogueira

    2016-06-01

    Threaded metal pins have been used to create additional retention for large composite resin restorations. However, their dark appearance may compromise esthetic outcome. The use of small fiberglass posts has been advocated as an alternative. This clinical report describes a mini fiberglass post (MFP) used to provide additional retention in a fractured anterior tooth that received a composite resin restoration. The MFP represents a promising option for creating additional retention for large composite resin restorations. PMID:26724848

  3. 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

  4. 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...

  5. 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 ...

  6. 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

  7. 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. PMID:22144797

  8. 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.

  9. 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

  10. Radiation modified filler for dental restorative composites

    International Nuclear Information System (INIS)

    Gamma-radiation was utilized to graft acrylic acid in the vapor phase to the surface of glass fibers and quartz particles. This treatment improved the wettability of the filler with the polymeric matrix and enhanced the mechanical properties of the composite. Samples were prepared from the unfilled dental resin, and from composites containing untreated, silane treated and polyacrylic acid-grafted fillers. These composites contained 30, 45 and 69 vol.% filler in each category. The composites containing grafted filler were superior in hardness and compressive strength, and equivalent in abrasion resistance to those with silane treated fillers. However, both treatments showed at least a 50% improvement in compressive strength and a 300% reduction in wear over composites with untreated filler. This improvement was even more substantial when glass fibers were used as the filler material. (author)

  11. 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...

  12. Bond Strength of Repaired Composite Resin Restorations

    Directory of Open Access Journals (Sweden)

    Rodrigo Máximo de ARAÚJO

    2007-05-01

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

  13. 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.

  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. 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

  16. 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

  17. 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...

  18. Microshear bond strength between restorative composites and resin cements

    OpenAIRE

    Rubens Nazareno GARCIA; Mário Fernando de GÓES; Marcelo GIANNINI

    2008-01-01

    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...

  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. 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 ...

  1. Evaluation of surface roughness of different restorative composites after polishing using atomic force microscopy

    OpenAIRE

    C Meena Kumari; K Manohar Bhat; Rahul Bansal

    2016-01-01

    Introduction: Resin based composites are widely used aesthetic restorative materials in clinical restorative dentistry. The filler size and the percentage of fillers affects smooth surface, clinical durability, aesthetics, better optical properties, compatibility with natural enamel tissue, surface gloss, and preventing the discoloration of the restoration. The finishing and polishing of tooth-coloured restorations are necessary clinical steps for better aesthetics and longevity of restored t...

  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. 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

  4. 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...

  5. 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

  6. 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

  7. 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

  8. 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...

  9. Clinical evaluation of direct composite restoration done for midline diastema closure – long-term study

    OpenAIRE

    Prabhu, R.; S Bhaskaran; Geetha Prabhu, K. R.; M A Eswaran; Phanikrishna, G.; Deepthi, B.

    2015-01-01

    Purpose of the Study: The aim of this study was to evaluate clinically the performance of composite resin used to restore midline diastema between the maxillary and mandibular central incisors. Methodology: Direct composite restorations were done for 45 patients with midline diastema between the maxillary and mandibular central incisors. Standard protocols were followed for the placement of composite resin for the diastema closure, and recall visits were made for every 6 months for a period o...

  10. 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...

  11. 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

  12. 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 ...

  13. 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...

  14. 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

  15. The role of emergence profile in papilla maintenance after diastema closure with direct composite resin restorations.

    Science.gov (United States)

    Sobrinho, Kleyver Nascimento; Lima, Liliane Motta de; Cohen-Carneiro, Flávia; Silva, Luciana Mendonça da; Martins, Leandro Moura; Pontes, Danielson Guedes

    2016-01-01

    The dental morphology usually determines the shape and volume of the interdental space, which must be filled by a dense connective tissue covered by oral epithelium to achieve pleasant esthetics. When composite resin restorations are placed to solve esthetic problems, the restorative procedure must be designed to allow the formation of healthy interdental papilla. This case report discusses aspects that should be considered when composite resin restorations are proposed for diastema closure. A 23-year-old man sought treatment for variations of space in the anterior dentition after orthodontic treatment. Direct composite resin restorations were placed in a way that respected the emergence profile, even though "black triangles" were evident immediately after the procedure. At the 45-day follow-up, complete closure of the interdental spaces by healthy papillae was observed. The emergence profile should be identified and respected when restorations are placed to obtain diastema closure because healthy periodontal tissues and acceptable esthetics depend on it. PMID:27148664

  16. Clinical evaluation of direct composite restoration done for midline diastema closure – long-term study

    Science.gov (United States)

    Prabhu, R.; Bhaskaran, S.; Geetha Prabhu, K. R.; Eswaran, M. A.; Phanikrishna, G.; Deepthi, B.

    2015-01-01

    Purpose of the Study: The aim of this study was to evaluate clinically the performance of composite resin used to restore midline diastema between the maxillary and mandibular central incisors. Methodology: Direct composite restorations were done for 45 patients with midline diastema between the maxillary and mandibular central incisors. Standard protocols were followed for the placement of composite resin for the diastema closure, and recall visits were made for every 6 months for a period of 60 months for evaluation of the success of these restorations made. Qualified dental personnel examined the restorations made. Results: Clinical evaluations were done after the restorations had been in place for an average of 6 months. Results indicate that none of the restorations were totally lost, and resulting in a 91% overall retention rate for the period of 60 months. About 62% of the restorations made had no noticeable color difference with that of the adjacent tooth, and gingival health indicated 73% of the sample was without any signs of inflammation. Conclusions: Composites restored for diastemas exhibit satisfactory survival rates placed with recommended placement protocols and without occlusal loading. PMID:26538917

  17. 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.

  18. 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....

  19. 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

  20. Demineralization around restorations with different restorative materials containing fluoride

    Directory of Open Access Journals (Sweden)

    Letícia Caliento Seixas

    2004-06-01

    Full Text Available The aim of this study was to evaluate in vitro the demineralization on tooth/restoration interface of eight restorative materials after demineralization/remineralization cycling. Eighty class V cavities were prepared with margins at enamel and dentin/cementum, and were restored with Fuji II LC, Fuji IX, Ketac-fil, Ketac Molar, Ariston pHc, Compoglass, Degufill Mineral and Z100. After the restorative procedures, the restorations were submitted to demineralization/ remineralization cycling during 14 days. Specimens were embedded in acrylic resin and submitted to serial sectioning. The sections were examined by optical microscope, and demineralization around restoration was measured on cervical and occlusal margins. The data were analyzed using the ANOVA and Tukey test (p<0.05. Glass ionomer cements showed less demineralization on enamel and dentin/restoration interfaces when compared to the tested composite resins (Z100 and Degufill Mineral. In conclusion, glass ionomer cements suffered less demineralization but did not protect completely the tooth/restoration interface.

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

    OpenAIRE

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

    2014-01-01

    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 (n=62) 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 in...

  2. 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

    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...... Class II, 4 SDR-CeramX mono+ and 6 CeramX mono+-only restorations. The main reasons for failure were tooth fracture (6) and secondary caries (4). The annual failure rate (AFR) for all restorations (Class I and II) was for the bulk-filled- 1.1% and for the resin composite-only restorations 1.3% (p>0...

  3. 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...... 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...... literature 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....

  4. Light induced polymerization of resin composite restorative materials

    Directory of Open Access Journals (Sweden)

    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.

  5. 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. PMID:26954878

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

    Directory of Open Access Journals (Sweden)

    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

  7. 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...... of the enamel. The chemical-cured resincomposites were placed in bulk and the light-cured in increments. One operator placed 99restorations (33 sets). The restorations were evaluated with slightly modified USPHS crite-ria at baseline, 2, 3, 5, 10, 15, 20 and 30 years. Statistical analyses were...... performed by theKaplan–Meier, log-rank test and Cox regression analyses. Results. After 30 years, 5 participants with 15 restorations (15%) could not be evaluated duringthe whole evaluation. Seven participants were considered as caries risk and eight partici-pants as having active parafunctional habits...

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

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2015-01-01

    Objective: To evaluate the durability of three conventional resin composites in Class II restorations during 27 years. Methods: Thirty participants, 25 female and 5 male (mean age 38.2 years, range 25–63), received at least three (one set) as similar as possible Class II restorations of moderate...... size. The three cavities were chosen at random to be restored with a chemical-cured (Clearfil Posterior) and two visible light-cured resin composites (Adaptic II, Occlusin). A chemical-cured enamel bonding agent (Clearfil New Bond) was applied after Ca(OH)2 covering of dentin and enamel etch. Marginal.......1%), followed by occlusal wear (21.6%) and material fracture (18.9%). Non-acceptable color match was seen in 24 (28.3%) of the restorations (AII 2, CP 16, O 6). Cox regression-analysis showed significant influence of the covariates tooth type, caries risk, and bruxing activity of the participants. Conclusions...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. One-year clinical evaluation of posterior packable resin composite restorations.

    Science.gov (United States)

    Loguercio, A D; Reis, A; Rodrigues Filho, L E; Busato, A L

    2001-01-01

    This study evaluated the clinical performance of four packable resin composite restorative materials in posterior teeth (Class I and II) compared with one hybrid composite after one year. Eighty-four restorations were placed in 16 patients. Each patient received at least five restorations. The tested materials were: (1) Solitaire + Solid Bond; (2) ALERT + Bond-1; (3) Surefil + Prime & Bond NT (4) Filtek P60 + Single Bond and; (5) TPH Spectrum + Prime & Bond 2.1. All restorations were made using rubber dam isolation, and the cavity design was restricted to the elimination of carious tissue. Deeper cavities were covered with calcium hydroxide and/or glass ionomer cement. In shallow and medium cavities, no protection was performed except for the respective adhesive system used in each group. Each adhesive system and resin composite was placed according to the manufacturer's instructions. One week later, the restorations were finished/polished and evaluated according to the USPHS modified criteria. All patients attended the one-year recall, and the 84 restorations were evaluated at that time based on the same evaluation criteria. The scores were submitted to statistical analysis (Chi-square test, p<0.05). Solitaire and TPH showed some fractures at marginal ridges. Solitaire, ALERT and TPH showed some concerns related to color match and surface texture. Surefil and Filtek P60 showed an excellent clinical performance after one year. PMID:11551005

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-15

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

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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...

  16. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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

  19. A comparison of microhardness of indirect composite restorative materials

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...

  20. 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.

  1. 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.

  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. 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

    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......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...

  5. 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. PMID:26158031

  6. Direct Composite Restorations to Mask Intrinsic Staining: An Eighteen-Year Follow-Up.

    Science.gov (United States)

    Mondelli, Rafael Francisco Lia; Soares, Ana Flávia; Tostes, Bhenya Ottoni; Bombonatti, Juliana Fraga Soares

    2016-03-01

    In this case example, the use of direct composite resin allowed for a relatively simple, conservative treatment that provided excellent function and aesthetics, while preserving healthy dental tissue. The importance of continued follow-up and a periodic maintenance and minor repair process will ensure longevity of the restorations, as aesthetics, and the occlusion. PMID:27039546

  7. 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....

  8. Influence of storage time in water on the integrity of adhesive interface in resin composite restorations

    Directory of Open Access Journals (Sweden)

    Tathy Aparecida Xavier

    2013-08-01

    Full Text Available When immersed in oral fluids, water absorption by the restorative resin composite material can occur, which is identified by some researchers as one of the causes of loss of aesthetic features and reduction of mechanical properties over time. On the other hand, some authors have suggested that the fluids sorption may contribute to the reduction of shrinkage stress generated at the adhesive interface and reduce the width of gaps. The aim of this study was verifying if the storage time in water of restorations carried out with different filling techniques could influence on the integrity of tooth-restoration adhesive interface. Eighteen cavities were built in bovine incisors and they were divided into 3 groups after the adhesive procedure: group B (“Bulk” received one single increment of light-cured resin composite; group I (“Increments” received the same composite in three oblique increments; and the group B+S (“Bulk + Self-cured resin composite”. The last one firstly received a flowable, self-cured resin composite, and then, it was inserted one single increment of light-cured composite. After 48 h of storage, the restorations were sliced, the first measurement was accomplished, and the analysis of the adhesive interface was made each 30 days over nine months of immersion in water. The results were subjected to a split-plot analysis of variance and Tukey’s test. It was not verified significant influence of immersion time in water on the gap width, or regular increase or decrease of percentage interface free of gaps over time for any of three filling techniques. Some hypothesis could explain this occurrence, such as gain of mass without significant increase in the volume; the expansion of restoration in directions that did not contributed to the gaps closure; and the simultaneous occurrence of hygroscopic expansion and hydrolytic degradation of the resin processes.

  9. NDE of the internal hole defect of dental composite restoration using infrared lock in thermography

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-02-15

    The purpose of this study was to detect the pin hole defect of dental composite restoration using lock in thermography method. Amplitude and phase images of the composite resin specimens were analyzed according to the lock in frequency and the diameter of defect area. Through the amplitude image analysis, at lock in frequency of 0.05 Hz, defect diameters 2-5 mm exhibited the highest amplitude contrast value between defective area and sound area. The lock in frequency range of 0.3-0.5 Hz provided good phase angle contrast for contrast value. It is concluded that the infrared lock in thermography method verified the effectiveness for detecting the pin hole defect of dental composite restoration.

  10. NDE of the internal hole defect of dental composite restoration using infrared lock in thermography

    International Nuclear Information System (INIS)

    The purpose of this study was to detect the pin hole defect of dental composite restoration using lock in thermography method. Amplitude and phase images of the composite resin specimens were analyzed according to the lock in frequency and the diameter of defect area. Through the amplitude image analysis, at lock in frequency of 0.05 Hz, defect diameters 2-5 mm exhibited the highest amplitude contrast value between defective area and sound area. The lock in frequency range of 0.3-0.5 Hz provided good phase angle contrast for contrast value. It is concluded that the infrared lock in thermography method verified the effectiveness for detecting the pin hole defect of dental composite restoration

  11. 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

  12. 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

  13. 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 at...... baseline and then annually for 10 years. The overall performance of the experimental restorations was tested after intra-individual comparison and their ranking was tested using Friedman's two-way ANOVA. The level of significance was set at 5%. Results: Four patient drop-outs with 8 restorations (4TEC, 4TC...

  14. 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

  15. 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.

  16. Comparing Effect of Four Different Restorative Techniques with Composite on Gingival Seal Located on the Dentin

    Directory of Open Access Journals (Sweden)

    AR Davari

    2014-08-01

    Full Text Available Introduction: In spite of improvements in composite function, marginal microleakage in deep composite restoration is still considered as a challenge due to unstable bond between composite and dentin. Therefore, this study aimed to investigate effect of applying different materials on marginal microleakage in posterior composite restoration. Methods: A standard distal box was prepared on 80 human premolar. The gingival floors were 1 millimeter under CEJ. The specimens were divided to four groups. In the first group, 1 millimeter amalgam was used as the first increment in proximal box on gingival floor, in the second group flow able composite, and in the third group, RMGI were used. Other cavities were filled by condensable composite. In the fourth group (control, all the cavities were filled only by condensable composite. The specimens, after 6 months of storage, were placed under cyclic load (10000 cycle- 80 N- 1 Hz, and then were immersed in 2% methylene blue for 6 hours. Afterwards, the specimens were sectioned in the middle of restoration. Extension of dye penetration at the cervical margin was examined under a stereo microscope at 25x magnification and the leakage was evaluated by Fuks degree. The study data were statistically analyzed using the Mann- Whitney U-test (p<0.05. Results: Microleakage was observed in all the groups. The third group demonstrated the most leakage and the least was for the first group. No statistically significant difference was observed between the groups. p-value =0.689 Conclusion: In cavities with gingival floor under CEJ, different filling methods have no effect on marginal sealing.

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

    Science.gov (United States)

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

    2009-01-01

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

  18. 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

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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

  4. Long-Term Provisional Bonded Composite Restorations Make Full-Mouth Rehabilitation Possible.

    Science.gov (United States)

    Wilkins, Ronald G

    2016-05-01

    Full-mouth rehabilitation cases frequently require an extended period to complete. In this case involving a patient who presented with a significant amount of lost tooth structure, treatment featured laboratory-fabricated composite provisional restorations aimed at stabilizing the dentition and enabling definitive treatment to be completed in segments. The approach taken allowed occlusal and esthetic issues to be resolved through use of the provisionals while minimizing tooth preparation. The technique provided immediate improvement in esthetics, function, and comfort. PMID:27213778

  5. 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...

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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

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

    Directory of Open Access Journals (Sweden)

    Horieh Moosavi

    2012-01-01

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

  12. Effect of various surface treatment methods on repair bond strength of composite restorations

    Directory of Open Access Journals (Sweden)

    Maryam Jafari

    2012-01-01

    Full Text Available AbstractIntroduction: In some cases repair of composite resin restorations is preferable to replacement. Various surface treatment methods have been introduced to improve the weak bond strength between the new and old composite resins. The aim of this study was to evaluate the effect of various surface treatment methods on repair bond strength of composite resin restorations.Materials and Methods: In this in vitro study, 56 composite resin specimens (Filtek Supreme were prepared and randomly divided into seven groups (one control group and six experimental groups. Then one of the surface treatment methods was used in the experimental groups as follows: group 1: diamond bur + phosphoric acid + bonding agent (Single Bond; group 2: diamond bur + phosphoric acid + silane + Single Bond; group 3: air abrasion (50-µm AL2O3 particles + phosphoric acid + Single Bond; group 4: air abrasion (50-µm AL2O3 particles + phosphoric acid + Silane + Single Bond; group 5: diamond bur + phosphoric acid + Clearfil Repair; group 6: diamond bur + phosphoric acid + Clearfil SE Bond. After bonding fresh composite resin, all the specimens were stored in distilled water at 37°C for 24h prior to measuring shear bond strength using a universal testing machine. Data were analyzed with one-way ANOVA and Tukey test (α=0.05.Results: The highest bond strength values were recorded in groups 2 and 5, with no significant differences (p value = 0.064; the lowest bond strength was recorded in group 1. Clearfil SB exhibited better results than Single Bond (p value = 0.039 and Clearfil Repair Bond exhibited better results than Clearfil SB Bond (p value = 0.038.Conclusion: Surface treatment with diamond bur was more effective than air abrasion. Use of silane was affective in increasing bond strength. Clearfil Repair Bond had the best effect on repair bond strength of composite resins.Key words: Air abrasion, Bonding agent, Composite resins, Dental, Silane.

  13. 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.

  14. Clinical Investigation of a New Bulk Fill Composite Resin in the Restoration of Posterior Teeth

    Science.gov (United States)

    2015-12-02

    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

  15. 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

  16. 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

  17. Marginal microleakage of cervical composite resin restorations bonded using etch-and-rinse and self-etch adhesives: two dimensional vs. three dimensional methods

    Science.gov (United States)

    Khoroushi, Maryam

    2016-01-01

    Objectives This study was evaluated the marginal microleakage of two different adhesive systems before and after aging with two different dye penetration techniques. Materials and Methods Class V cavities were prepared on the buccal and lingual surfaces of 48 human molars. Clearfil SE Bond and Single Bond (self-etching and etch-and-rinse systems, respectively) were applied, each to half of the prepared cavities, which were restored with composite resin. Half of the specimens in each group underwent 10,000 cycles of thermocycling. Microleakage was evaluated using two dimensional (2D) and three dimensional (3D) dye penetration techniques separately for each half of each specimen. Data were analyzed with SPSS 11.5 (SPSS Inc.), using the Kruskal-Wallis and Mann-Whitney U tests (α = 0.05). Results The difference between the 2D and 3D microleakage evaluation techniques was significant at the occlusal margins of Single bond groups (p = 0.002). The differences between 2D and 3D microleakage evaluation techniques were significant at both the occlusal and cervical margins of Clearfil SE Bond groups (p = 0.017 and p = 0.002, respectively). The difference between the 2D and 3D techniques was significant at the occlusal margins of non-aged groups (p = 0.003). The difference between these two techniques was significant at the occlusal margins of the aged groups (p = 0.001). The Mann-Whitney test showed significant differences between the two techniques only at the occlusal margins in all specimens. Conclusions Under the limitations of the present study, it can be concluded that the 3D technique has the capacity to detect occlusal microleakage more precisely than the 2D technique. PMID:27200275

  18. 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

  19. 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)

  20. 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)

  1. 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.

  2. 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

  3. 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 (JA...... common to class V chitinases from higher plants....

  4. 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

    OpenAIRE

    Fabiana Mantovani Gomes França; Frederico Seidi Hori; Alex José Souza dos Santos; José Roberto Lovadino

    2005-01-01

    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 "sof...

  5. A randomized double-blind clinical trial of posterior composite restorations with or without bevel: 1-year follow-up

    Directory of Open Access Journals (Sweden)

    Fábio Herrmann Coelho-De-Souza

    2012-04-01

    Full Text Available OBJECTIVE: This randomized double-blind clinical trial compared the performance of posterior composite restorations with or without bevel, after 1-year follow-up. MATERIAL AND METHODS: Thirteen volunteers requiring at least two posterior composite restorations were selected. Twenty-nine cavities were performed, comprising 14 without bevel (butt joint and 15 with bevel preparation of the enamel cavosurface angle. All cavities were restored with simplified adhesive system (Adper Single Bond and composite resin (Filtek P60. A halogen light curing unit was used through the study. Restorations were polished immediately. Analysis was carried out at baseline, after 6 months and after 1 year by a calibrated evaluator (Kappa, according to the FDI criteria. Data were statistically analyzed by Mann-Whitney test (p <0.05. RESULTS: Beveled and non-beveled cavities performed similarly after 1 year follow-up, regarding to fractures and retention, marginal adaptation, postoperative hypersensitivity, recurrence of caries, surface luster and anatomic form. However, for surface and marginal staining, beveled cavities showed significantly better performance (p<0.05 than butt joint restorations. CONCLUSIONS: It was concluded that the restorations were acceptable after 1 year, but restorations placed in cavities with marginal beveling showed less marginal staining than those placed in non-beveled cavities.

  6. Clinical and Experimental Evaluation of the Effectiveness of «Soft-Start» Polymerization in Dental Composite Restoration

    Directory of Open Access Journals (Sweden)

    Timur V. Melkumyan, PhD, ScD

    2012-09-01

    Full Text Available The clinical and experimental efficiency of the soft-start polymerization technique in composite restorations was studied. In this study, 57 patients between 30 and 44 years of age with secondary caries had 158 restorations done using the photo-composite material Filtek Z250. The restorations performed were distinguished into two groups, the basis of the photo-polymerization method of employed (conventional polymerization technique and «soft-start» polymerization technique. The objects of the study also included the specimens of 18 extracted teeth. The analysis of the data indicates that employing the «soft-start» polymerization technique provides better integration of the composite material to the hard tissues of the tooth. This conclusion was best demonstrated in cases where the dentin was a connecting link in the chain «substrate-hybrid layer-composite».

  7. 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...

  8. Computed-tomography scan-based finite element analysis of stress distribution in premolars restored with composite resin

    International Nuclear Information System (INIS)

    Mechanical properties of restorative material have an effect on stress distribution in the tooth structure and the restorative material during mastication. The aim of this study was to investigate the influence of restorative materials with different moduli of elasticity on stress distribution in the three-dimensional (3D) solid tooth model. Computed tomography scan data of human maxillary second premolars were used for 3D solid model generation. Four composite resins with a modulus of elasticity of 6700, 9500, 14 100 and 21 000 MPa were considered to simulate four different clinical direct restoration types. Each model was subjected to a resulting force of 200 N directed to the occlusal surface, and stress distribution and maximal von Mises stresses were calculated using finite-element analysis. We found that the von Mises stress values and stress distribution in tooth structures did not vary considerably with changing the modulus of elasticity of restorative material.

  9. Reasons for Retreatment of Amalgam and Composite Restorations among the Patients Referring to Tabriz Faculty of Dentistry

    OpenAIRE

    2007-01-01

    Background and aims Retreatment of existing restorations not only requires a lot of money and time but also there is a danger of weakening tooth structure and irritating the pulp. Since awareness of the reasons for the retreatment of teeth will save the teeth from possible future failure, the aim of this study was to assess the reasons for retreatment of amalgam and composite restorations in patients referring to Tabriz Faculty of Dentistry. Materials and methods In this descriptive study, th...

  10. 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...

  11. 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 ...

  12. 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

  13. Reasons for Retreatment of Amalgam and Composite Restorations among the Patients Referring to Tabriz Faculty of Dentistry

    Science.gov (United States)

    Kimyai, Soodabeh; Mehdipour, Masomeh; Savadi Oskoee, Siavash; Alizadeh Oskoee, Parnian; Abbaszadeh, Armin

    2007-01-01

    Background and aims Retreatment of existing restorations not only requires a lot of money and time but also there is a danger of weakening tooth structure and irritating the pulp. Since awareness of the reasons for the retreatment of teeth will save the teeth from possible future failure, the aim of this study was to assess the reasons for retreatment of amalgam and composite restorations in patients referring to Tabriz Faculty of Dentistry. Materials and methods In this descriptive study, the subjects had previously received an amalgam or a composite restoration in the Operative Department by dental students and were judged to need retreatment in their second visit. A total of 300 defective teeth were selected by simple random sampling method. The data was collected through examination and questionnaires and analyzed using chi-square test. Results There was a statistically significant association between the type of the restorative material and the reason for retreatment (p=0.001). Conclusion Although the reasons for the retreatment of amalgam and composite restorations were different, recurrent caries was the main reason for the retreatment for both restorative materials. PMID:23277830

  14. 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.

  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)

    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

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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...

  3. 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 ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-12-15

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

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

    International Nuclear Information System (INIS)

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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

    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...

  13. 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.

  14. 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 < 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.

  15. 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.

  16. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration

    OpenAIRE

    Ritts, Andy Charles; Li, Hao; Yu, Qingsong; Xu, Changqi; Yao, Xiaomei; Hong, Liang; Wang, Yong

    2010-01-01

    The objective of this study is to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces for composite restoration. Extracted unerupted human third molars were used by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated by using a non-thermal atmospheric argon plasma brush for various durations. The molecular changes of the dentin surfaces were analyzed using FTIR/ATR and an increase in...

  17. 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 ...

  18. 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...

  19. 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...

  20. 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

  1. 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.

  2. Non-thermal Atmospheric Plasma Treatment for Deactivation of Oral Bacteria and Improvement of Dental Composite Restoration

    Science.gov (United States)

    Yu, Qing Song; Li, H.; Ritts, A. C.; Yang, B.; Chen, M.; Hong, L.; Xu, C.; Yao, X.; Wang, Y.

    This paper reviews our recent research results of using non-thermal ­atmospheric plasmas for oral bacterial deactivation and for composite restoration improvement. Oral bacteria of Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acidophilus) with an initial bacterial population density between 1.0 × 108 and 5.0 × 108 cfu/ml were seeded on various media and their survivability with plasma exposure was examined. The plasma exposure time for a 99.9999% cell reduction was less than 15 s for S. mutans and within 5 min for L. acidophilus. To evaluate the dentin/composite interfacial bonding, extracted unerupted human third molars were used by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. After dental composite application and light curing, the teeth were then sectioned into micro-bars as the specimens for microtensile test. Student Newman Keuls (SNK) tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s plasma treatment of the dentin surfaces. These findings indicated that non-thermal atmospheric plasma technology is very promising for dental clinical applications.

  3. 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...

  4. 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...

  5. 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

  6. 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)

  7. 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

  8. INDIRECT FIBER-REINFORCED RESIN COMPOSITE RESTORATIONS FOR MANDIBULAR ANTERIOR DENTITION (18 MONTH FOLLOW UP)

    OpenAIRE

    BAYINDIR, Funda; DIKEÇ, Engin Volkan

    2015-01-01

    ABSTRACT The mandibular anterior tooth loss because of trauma or periodontal problems is seen frequently. In some cases, the presence of a diastema between teeth is a common feature found in the mandibular anterior dentition. Many forms of therapy can be used for diastema closure. A carefully developed diagnosis and advanced planning allows the most appropriate treatment to address the patient's needs. Among the suggested options are for diastema closure such as orthodontic, restorative and p...

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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; Hallonsten, Anna-Lena; Höigaard, Ruth

    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....

  14. Ex vivo fracture resistance of endodontically treated maxillary central incisors restored with fiber-reinforced composite posts and experimental dentin posts

    OpenAIRE

    Ambica Kathuria; Kavitha, M.; Suchit Khetarpal

    2011-01-01

    Aim : To compare the fracture resistance of teeth restored with fiber-reinforced composite (FRC) posts and experimental dentin posts milled from human root dentin. Materials and Methods : Thirty maxillary central incisors were divided into three groups of ten each. Twenty teeth were restored with FRC posts and solid dentin posts and numbered as Groups 2 and 3 respectively while Group 1 acted as the control, without any post. The teeth were loaded at 135° angle to their long axes after co...

  15. Failure Rate of Direct High-Viscosity Glass-Ionomer Versus Hybrid Resin Composite Restorations in Posterior Permanent Teeth - a Systematic Review

    Science.gov (United States)

    Mickenautsch, Steffen; Yengopal, Veerasamy

    2015-01-01

    Purpose Traditionally, resin composite restorations are claimed by reviews of the dental literature as being superior to glass-ionomer fillings in terms of restoration failures in posterior permanent teeth. The aim of this systematic review is to answer the clinical question, whether conventional high-viscosity glass-ionomer restorations, in patients with single and/or multi-surface cavities in posterior permanent teeth, have indeed a higher failure rate than direct hybrid resin composite restorations. Methods Eight databases were searched until December 02, 2013. Trials were assessed for bias risks, in-between datasets heterogeneity and statistical sample size power. Effects sizes were computed and statistically compared. A total of 55 citations were identified through systematic literature search. From these, 46 were excluded. No trials related to high-viscosity glass-ionomers versus resin composite restorations for direct head-to-head comparison were found. Three trials related to high-viscosity glass-ionomers versus amalgam and three trials related to resin composite versus amalgam restorations could be included for adjusted indirect comparison, only. Results The available evidence suggests no difference in the failure rates between both types of restoration beyond the play of chance, is limited by lack of head-to-head comparisons and an insufficient number of trials, as well as by high bias and in-between-dataset heterogeneity risk. The current clinical evidence needs to be regarded as too poor in order to justify superiority claims regarding the failure rates of both restoration types. Sufficiently large-sized, parallel-group, randomised control trials with high internal validity are needed, in order to justify any clinically meaningful judgment to this topic. PMID:26962372

  16. 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...

  17. 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...

  18. Effect of Bleaching Agents on the Nanohardness of Tooth Enamel, Composite Resin, and the Tooth-Restoration Interface.

    Science.gov (United States)

    Abe, A T; Youssef, M N; Turbino, M L

    2016-01-01

    This in vitro study aimed to evaluate the nanohardness of tooth enamel, composite resin, dental adhesive, and enamel hybrid layer exposed to 35% hydrogen peroxide-based bleaching agents and analyze the tooth-restoration interface using scanning electron microscopy (SEM). This study used 40 crowns of bovine incisors, which were embedded in epoxy resin. A 2 × 2 × 2-mm cavity was prepared in the medial third of the flattened buccal surface of each tooth and restored (two-step etch-and-rinse Adper Single Bond 2 + nanocomposite resin Filtek Z350 XT). The specimens were polished and divided into four groups (n=10), corresponding to each bleaching agent used (TB: Total Blanc Office, pH=7.22-6.33; HPB: Whiteness HP Blue, pH=8.89-8.85; HP: Whiteness HP, pH=6.65-6.04; PO: Pola Office, pH=3.56-3.8), applied in accordance with manufacturer protocols. The nanohardness of the substrates was measured before and immediately after the bleaching procedure and after 7-day storage in artificial saliva with an Ultra-Microhardness Tester (DUH-211S, Shimadzu). Loads used were 100 mN for tooth enamel and composite resin and 10 mN for adhesive and enamel hybrid layer. For SEM analysis, epoxy replicas were prepared through high-precision impressions of the specimens. For nanohardness, the statistical tests two-way analysis of variance and Tukey (pinterface was observed immediately after application of agent PO. No bleaching agent used changed the nanohardness of the composite resin and adhesive layer. PMID:26266649

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

    OpenAIRE

    Arash Poorsattar Bejeh Mir; Zahra Bani Ameri; Vahid Soltankarimi; Hengame Saffarcherati; Mitra Tabari

    2012-01-01

    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 ...

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  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. 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.

  6. 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

  7. 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

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

    Science.gov (United States)

    Preoteasa, E. A.; Ciortea, C.; Constantinescu, B.; Fluerasu, D.; Enescu, S.-E.; Pantelica, D.; Negoita, F.; Preoteasa, E.

    2002-04-01

    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. 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

  10. 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.

  11. Evaluation of the effect of water on three different light cured composite restorative materials stored in water: an in vitro study.

    Science.gov (United States)

    Biradar, Basawaraj; Biradar, Sudharani; Ms, Arvind

    2012-01-01

    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. PMID:22315607

  12. Lime-pozzolana mortars in Roman catacombs: composition, structures and restoration

    International Nuclear Information System (INIS)

    Analyses of microsamples collected from Roman catacombs and samples of lime-pozzolana mortars hardened in the laboratory display higher contents in carbonated binder than other subaerial Roman monuments. The measured environmental data inside the Saint Callistus and Domitilla catacombs show a constant temperature of 15-17 deg C, a high CO2 content (1700 to 3500 ppm) and a relative humidity close to 100%. These conditions and particularly the high CO2 concentration speed-up the lime calcitization roughly by 500% and reduce the cationic diffusion to form hydrous calcium aluminosilicates. The structure of Roman catacomb mortars shows (i) coarser aggregates and thicker beds on the inside, (ii) thin, smoothed, light and fine-grained external surfaces with low content of aggregates and (iii) paintings and frescoes on the outside. The observed high porosity of the mortars can be attributed to cracking after drying linked with the high binder content. Hardened lime lumps inside the binder denote low water/mortar ratios for slaking. The aggregate tephra pyroclasts rich in aluminosilicate phases with accessorial amounts of Ba, Sr, Rb, Cu and Pb were analysed through X-ray diffraction (XRD), electron microprobe analysis (EMPA) and also by environmental scanning electron microscopy (ESEM) to identify the size and distribution of porosity. Results support procedures using local materials, special mortars and classic techniques for restoration purposes in hypogeal backgrounds

  13. 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...

  14. Fracture strength of endodontically-treated teeth restored with post and cores and composite cores only.

    Science.gov (United States)

    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 randomly divided into seven experimental groups: Gr1: Titanium posts (ParaPost) + Silano-Pen (Bredent) + silane; Gr2: Titanium posts + 30 microm CoJet-Sand (3M ESPE) + silane; Gr3: Titanium posts + 50 microm Al2O3 + V-primer (Sun Medical); Gr4: Titanium posts + 50 microm Al2O3 + Alloy primer (Kuraray); Gr5: E-glass FRC post (EverStick); Gr6: Polyethylene fiber (Ribbond) + Resin impregnation and Gr7: Resin composite core only, with no posts. The posts were cemented using Panavia F 2.0 (Kuraray); coronal parts of the roots were etched, primed, bonded and composite cores were built-up. After thermocycling (5 degrees C-55 degrees C, 6000x), the fracture strength test was performed. The fracture strength of titanium posts (408 +/- 122 - 550 +/- 149 N) was significantly higher (pE-glass FRC group, 60% adhesive core fracture occurred, covering >1/3 of the core and, in the polyethylene FRC group, 100% post-core detachment at the canal opening was observed. In all the titanium post applied groups (Gr1-Gr4), the posts remained in place with partial detachment of the core material from the post surface at varying degrees, depending on the conditioning method used. When no coronal tooth structure exist, the metal posts showed higher fracture strength values as opposed to the FRC post or no-post approach. PMID:19678448

  15. 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

  16. 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...

  17. 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....

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

    Science.gov (United States)

    Garoushi, Sufyan; Yokoyama, Daiichiro; Shinya, Akikazu; Vallittu, Pekka K

    2007-01-01

    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). PMID:21503213

  19. Effect of deproteinization and tubular occlusion on microtensile bond strength and marginal microleakage of resin composite restorations

    Directory of Open Access Journals (Sweden)

    Wagner Baseggio

    2009-10-01

    Full Text Available Dentin adhesion procedure presents limitations, especially regarding to lifetime stability of formed hybrid layer. Alternative procedures have been studied in order to improve adhesion to dentin. OBJECTIVE: The aim of this study was to evaluate in vitro the influence of deproteinization or dentin tubular occlusion, as well as the combination of both techniques, on microtensile bond strength (µTBS and marginal microleakage of composite resin restorations. MATERIAL AND METHODS: Extracted erupted human third molars were randomly divided into 4 groups. Dentin surfaces were treated with one of the following procedures: (A 35% phosphoric acid gel (PA + adhesive system (AS; (B PA + 10% NaOCl + AS; (C PA + oxalate + AS and (D PA + oxalate + 10% NaOCl + AS. Bond strength data were analyzed statistically by two-way ANOVA and Tukey's test. The microleakage scores were analyzed using Kruskal-Wallis and Mann-Whitney non-parametric tests. Significance level was set at 0.05 for all analyses. RESULTS: µTBS data presented statistically lower values for groups D and B, ranking data as A>C>B>D. The use of oxalic acid resulted in microleakage reduction along the tooth/restoration interface, being significant when used alone. On the other hand, the use of 10% NaOCl alone or in combination with oxalic acid, resulted in increased microleakage. CONCLUSIONS: Dentin deproteinization with 10% NaOCl or in combination with oxalate significantly compromised both the adhesive bond strength and the microleakage at interface. Tubular occlusion prior to adhesive system application seems to be a useful technique to reduce marginal microleakage.

  20. 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/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. PMID:26347900

  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. Wear mechanisms of dental composite restorative materials by two different in-vitro methods

    Directory of Open Access Journals (Sweden)

    Juliana Antonino de Souza

    2013-04-01

    Full Text Available In this work two very simple apparatuses, namely the ball crater (or ball-on-plate and the linear reciprocating (or pin-on-plate tests, were used in order to investigate the wear mechanisms of TPH Spectrum® and Resilab Master® dental composite resins. Loads in the range of 100 g to 1 kg and a total number of up to 24000 cycles were employed. During some of these tests, aqueous aluminum oxide suspensions were used as abrasive agent either diluted or not in distilled water. In case of the ball-on-plate test wear is dominated by abrasive and/or adhesive mechanisms, and is characterized by scratches which are composed of wear defects comprising particle detachment, wear of the polymer matrix and ceramic particle abrasion. However, the relative contributions of the two wear mechanisms could not be determined separately. In case of the pin-on-plate test wear is governed by the fatigue mechanism, although abrasive and adhesive wear mechanism are also present. After a certain number of cycles fatigue wear dominates the wear behavior and results in severe material loss. This mechanism seems to be more important in case of more brittle materials and when higher loads are employed. Qualitative analysis of the results suggests that the combination of these two very simple methods under appropriate conditions can yield sound results which may be representative of a number of clinical situations.

  3. 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.

  4. Effect of Opaque Layer Application on the Color of Resin Composites Used to Fill Access Openings of Screw-Retained Implant Restorations.

    Science.gov (United States)

    Cakan, Umut; Kara, Haluk Baris

    2015-01-01

    The purpose of this preliminary in vitro study was to evaluate the effect of an opaque layer and application of resin composite in dual colors on the ΔE values of resin composites used to fill access openings of screw-retained implant restorations. Sixty cylindrical nickel-chromium metal molds with a central channel simulating a posterior screw-retained, implant-supported, porcelain-fused-to-metal crown were cast. Access openings were filled with combinations of opaquer, enamel composite (A2E), dentin composite (A2B and A3B), and resilient composite. ΔE values differed significantly among the groups (P<.01). The combination of opaque layer and dual color resin composites of shades A2E and A3B resulted in significantly lower ΔE values than the other groups (P<.01). PMID:26218028

  5. Survival of Composite Resin Restorations of severely Decayed Primary Anterior Teeth retained by Glass Fiber Posts or Reversed-orientated Metal Posts

    Science.gov (United States)

    Ranjkesh, Bahram; Lovschall, Henrik; Erfanparast, Leila; Jafarabadi, Mohammad A; Oskouei, Sina Ghertasi; Isidor, Flemming

    2016-01-01

    ABSTRACT Aim: The aim of this study was to compare the survival of composite resin restorations retained by glass fiber posts or reversed-orientated (upside-down) metal posts in severely decayed primary anterior teeth after 6, 12, and 18 months. Materials and methods: A total of forty-four 3- to 5-year-old children with bilateral severely decayed primary maxillary canines were included. Patients were treated under general anesthesia. After pulpectomy, an intracanal post was seated in the primary maxillary canine on each side: either a glass fiber post or a metallic post in reversed orientation and teeth restored with light-cured composite. Survival rate of each technique was evaluated at predetermined follow-ups and data were analyzed with McNemar’s test (α = 0.05). Results: The difference in survival of restorations retained by two types of posts was not statistically significant in clinical and radiographical evaluations after 6, 12, and 18 months. The survival rate of reversed-orientated metal and glass fiber posts after 18 months was 81.1 and 67.6% respectively (p = 0.14). Conclusion: Reversed-orientated metal post did not show lower clinical survival compared with glass fiber posts in 18-month follow-up. Hence, reversed-orientated metal post can be considered as a potential method to obtain retention for composite restorations in severely decayed primary anterior teeth. How to cite this article: Vafaei A, Ranjkesh B, L0vschall H, Erfanparast L, Jafarabadi MA, Oskouei SG, Isidor F. Survival of Composite Resin Restorations of severely Decayed Primary Anterior Teeth retained by Glass Fiber Posts or Reversed-orientated Metal Posts. Int J Clin Pediatr Dent 2016;9(2):109-113. PMID:27365929

  6. 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.

  7. 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

  8. Microtensile bond strength of restorative composite bonded with self-adhesive resin cements to enamel and dentin

    Directory of Open Access Journals (Sweden)

    Mohammed Al-Saleh

    2013-04-01

    Full Text Available PURPOSE: To determine the microtensile bond strength (µTBS of composite restorations when bonded with self-adhesive resin-cements. METHODS: Thirty caries-free extracted molars were sterilized, and divided into 5 equal groups according to adhesive used: SBMP (Scotch-Bond-Multipurpose, total-etch 3-step adhesive, 3M/ESPE, PAN (PanaviaF-2.0, resin-cement with self-etch primer, Kuraray, RXU (RelyX-Unicem, self-adhesive resin-cement, 3M/ESPE, BRZ (Breeze, self-adhesive resin-cement, Pentron and MON (Monocem, self-adhesive resin-cement, Shofu. Each group was divided into 2 subgroups (dentin or enamel. Bonding agents, used according to manufacturers’ directions, or a thin layer of resin cement was applied onto teeth flat surfaces. Six mm-thick Filtek-Z250 (3M/ESPE composite build up was made in three increments. Teeth were sectioned to obtain rectangular specimens which were subjected to tensile force until failure. Specimens were subjected to 1,000 thermo-cycles between 5oC-55°C. Means and standard deviation (SD were calculated and statistically-analyzed with ANOVA and Tukey’s t-test. Specimens’ failure modes were reported. RESULTS: SBMP showed the highest µTBS results with enamel (24.6(6.1 MPa, PAN showed high µTBS with enamel (12.1(3.9MPa and dentin (11.6(4.7MPa compared to the other self-adhesive cements. Failure modes were adhesive and mixed for self-adhesive resin-cements. MON subgroups and BRZ enamel subgroup underwent premature failure. CONCLUSION: self-adhesive resin-cements showed low µTBS compared to SBMP.

  9. 40 CFR 144.83 - Do I need to notify anyone about my Class V injection well?

    Science.gov (United States)

    2010-07-01

    ... (prior to construction of your well) . . . then you must contact your State UIC Program to determine what...) . . . then you must contact your State UIC Program to determine what you must submit and by when. . . . then... information you must submit: (i) No matter what type of Class V well you own or operate, you must submit...

  10. 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

    -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......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....... Results: One hundred and fifty-eight restorations were evaluated after 8 years. Three participants with five restorations (three Xeno III, two Excite) were registered as dropouts. Twenty-one failed restorations (13.3 %) were observed during the follow-up. Twelve in the one-step self-etch adhesive group...

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

    Directory of Open Access Journals (Sweden)

    Geórgia Linhares dos Santos

    2014-01-01

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

  12. 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...

  13. 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

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

    International Nuclear Information System (INIS)

    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−1 in mixed ponds vs. 0.1% day−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 wetland

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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.

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

    OpenAIRE

    2015-01-01

    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 MP...

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. A support of restoration intervention of the bust of St. Gregory the Armenian: Compositional investigations by laser induced breakdown spectroscopy

    Science.gov (United States)

    Acquaviva, S.; De Giorgi, M. L.; Marini, C.; Poso, R.

    2005-07-01

    Laser induced breakdown spectroscopy was employed in the restoration process of the bust of St. Gregory the Armenian. It was applied to carry out elemental chemical analyses of different details of the bust. The analyses showed that all the investigated pieces are covered by polluted layers, rich mainly in calcium which can be removed by laser ablation. The investigations performed on the cleaned surfaces confirm that the hair is composed essentially of silver and the stole of copper and that no foils were added during the stages of artwork realization. The interesting finding is that the decorative coating of the stole was realized in gold, instead of the supposed brass.

  6. 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.

  7. 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)

  8. 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...

  9. 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

  10. Restoring forests

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...... scales. The capacity for new concepts and technologies to be adopted by managers and accepted by society will depend on effective technology transfer and a community-based approach to forest restoration. The many benefits human society gains from forests requires that forest restoration considers...

  11. 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)

  12. 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

  13. 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

  14. 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

  15. 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

    Class V restorations were placed with the self-etching primer Xeno III and a resin composite (Tetric Ceram) or a poly-acid modified resin composite (Dyract AP) in non-carious cervical lesions without intentional enamel involvement. The materials were cured with a conventional continuous light, a soft...... fulfilled at 18 months the full acceptance ADA criteria. Tetric Ceram showed at 7 years a 20.9% loss of retention and Dyract AP a 25.0% loss rate (Log rank p=0.48). The loss rates for the 3 curing techniques: continuous, soft start and pulse delay were 17%, 27.9% and 24.4%, respectively (Log rank p=0...

  16. 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

  17. 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

  18. 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

    -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...

  19. 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...

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

    International Nuclear Information System (INIS)

    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.

  1. 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.

  2. Intraoral repair of cosmetic restorations.

    Science.gov (United States)

    Denehy, G; Bouschlicher, M; Vargas, M

    1998-10-01

    The longevity of porcelain and composite resin restorations can often be prolonged by using sound principles, up-to-date materials, and judicious attention to repair when fracture problems arise. Careful case selection and correct usage of surface treatment agents, followed by the use of a quality bonding system and restorative materials, can result in a repair that exhibits excellent retention and natural color blending. This article outlines procedures and materials to repair both resin composite and porcelain intraorally. PMID:9891653

  3. 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

  4. Restoration and Archiving of Data from the Plasma Composition Experiment on the International Sun-Earth Explorer One (ISEE 1)

    Science.gov (United States)

    Lennartsson, O. W.

    1997-01-01

    The objective of this project has been to complete the archiving of energetic (10 eV/epsilon - 18 keV/epsilon) ion composition data from the Lockheed Plasma Composition Experiment on the International Sun-Earth Explorer One (ISEE 1) satellite, using a particular data format that had previously been approved by NASA and the NSSDC. That same format, a combination of ion velocity moments and differential flux spectra, had been used in 1991 to archive, at the NSSDC, the first 28 months (the "Prime" period of ISEE investigations) of data from the Lockheed instrument under NASA Contract NAS5-33047. With the completion of this project, the almost 4 1/2-year time span of these unique data is now covered by a very compact set, approximately 1 gigabyte in total, of electronic files with physical quantities, all in ASCII. The files are organized by data type and time of data acquisition, in Universal Time, and named according to year and day of year. Each calendar day has five separate files (five types of data), the lengths of which vary from day to day, depending on the instrument mode of operation. The data format and file structure are described in detail in appendices 1 and 2. The physical medium consists of high-density (6250 cpi) 9-track magnetic tapes, complemented by a set of hardcopy line plots of certain plasma parameters. In this case there are five tapes, to be added to the six previous ones from 1991, and 25 booklets of plots, one per month, to be added to the previous 28. The tapes, including an extra standard-density (1600 cpi) tape with electronic versions of the Data User's Guide and self-guiding VAX/VMS command files, and the hardcopy plots are being boxed for shipment to the NSSDC.

  5. Depth-dependent variations of sedimentary dissolved organic matter composition in a eutrophic lake: Implications for lake restoration.

    Science.gov (United States)

    Xu, Huacheng; Guo, Laodong; Jiang, Helong

    2016-02-01

    Dissolved organic matter (DOM) plays a significant role in regulating nutrients and carbon cycling and the reactivity of trace metals and other contaminants in the environment. However, the environmental/ecological role of sedimentary DOM is highly dependent on organic composition. In this study, fluorescence excitation emission matrix-parallel factor (EEM-PARAFAC) analysis, two dimensional correlation spectroscopy (2D-COS), and ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) were applied to investigate the depth-dependent variations of sediment-leached DOM components in a eutrophic lake. Results of EEM-PARAFAC and 2D-COS showed that fluorescent humic-like component was preferentially degraded microbially over fulvic-like component at greater sediment depths, and the relative abundance of non-fluorescent components decreased with increasing depth, leaving the removal rate of carbohydrates > lignins. The predominant sedimentary DOM components derived from FT-ICR-MS were lipids (>50%), followed by lignins (∼15%) and proteins (∼15%). The relative abundance of carbohydrates, lignins, and condensed aromatics decreased significantly at greater depths, whereas that of lipids increased in general with depth. There existed a significant negative correlation between the short-range ordered (SRO) minerals and the total dissolved organic carbon concentration or the relative contents of lignins and condensed aromatics (p < 0.05), suggesting that SRO mineral sorption plays a significant role in controlling the composition heterogeneity and releasing of DOM in lake sediments. Higher metal binding potential observed for DOM at deeper sediment depth (e.g., 25-30 cm) supported the ecological safety of sediment dredging technique from the viewpoint of heavy metal de-toxicity. PMID:26706464

  6. 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...

  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. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. Site Restoration

    International Nuclear Information System (INIS)

    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

  15. 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.

  16. 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.…

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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

  2. Site Restoration

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-04-01

    The objectives, the programme, and the achievements of SCK-CEN's Site Restoration Department for 2001 are described. Main activities include the decommissioning of the BR3 PWR-reactor as well as other clean-up activities, projects on waste minimisation and the management of spent fuel and the flow of dismantled materials and the recycling of materials from decommissioning activities based on the smelting of metallic materials in specialised foundries. The department provides consultancy and services to external organisations and performs R and D on new techniques including processes for the treatment of various waste components including the reprocessing of spent fuel, the treatment of tritium, the treatment of liquid alkali metals into cabonates through oxidation, the treatment of radioactive organic waste and the reconditioning of bituminised waste products.

  3. 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

  4. 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.

  5. 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,...

  6. Composition

    DEFF Research Database (Denmark)

    2014-01-01

    Memory Pieces are open compositions to be realised solo by an improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them...

  7. 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...

  8. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2011-01-01

    Strategies are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full...

  9. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound/video files will in some cases only provide a few minutes' sample, or the visuals will not appear at all...

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. The Gelså River Restoration Revisited

    DEFF Research Database (Denmark)

    Friberg, Nikolai; Baattrup-Pedersen, Annette; Kristensen, Esben; Kronvang, Brian; Larsen, Søren Erik; Pedersen, Morten Lauge; Skriver, Jens; Thodsen, Hans; Wiberg-Larsen, Peter

    2014-01-01

    The study was undertaken on the River Gelså, Denmark, where a 1.8 km meandering course was estab-lished in 1989 to replace a channelized river reach. This restoration project was the first of its kind inDenmark and has the longest time-series of post-intervention data of any restoration project...... conductedworld-wide. Additionally, a 0.5 km upstream (control) reach that remained channelized has been sampledsince 1989. In this paper, we examined macroinvertebrate assemblages in distinct habitats in 2008, 19years after the restoration, and community persistence between two years, 1997 and 2008, to...... investigatethe longer-term effects of restoration on the biota. We found that habitat type influenced macroinverte-brate community composition to some degree, while there were no clear effects on - and -diversity ofhabitat or reach type. Stony substrate habitats introduced as part of the restoration could...

  15. 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

  16. 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

  17. Performance of the THS4302 and the Class V Radiation-Tolerant THS4304-SP Silicon Germanium Wideband Amplifiers at Extreme Temperatures

    Science.gov (United States)

    Patterson, Richard L.; Elbuluk, Malik; Hammoud, Ahmad; VanKeuls, Frederick W.

    2009-01-01

    This report discusses the performance of silicon germanium, wideband gain amplifiers under extreme temperatures. The investigated devices include Texas Instruments THS4304-SP and THS4302 amplifiers. Both chips are manufactured using the BiCom3 process based on silicon germanium technology along with silicon-on-insulator (SOI) buried oxide layers. The THS4304-SP device was chosen because it is a Class V radiation-tolerant (150 kRad, TID silicon), voltage-feedback operational amplifier designed for use in high-speed analog signal applications and is very desirable for NASA missions. It operates with a single 5 V power supply [1]. It comes in a 10-pin ceramic flatpack package, and it provides balanced inputs, low offset voltage and offset current, and high common mode rejection ratio. The fixed-gain THS4302 chip, which comes in a 16-pin leadless package, offers high bandwidth, high slew rate, low noise, and low distortion [2]. Such features have made the amplifier useful in a number of applications such as wideband signal processing, wireless transceivers, intermediate frequency (IF) amplifier, analog-to-digital converter (ADC) preamplifier, digital-to-analog converter (DAC) output buffer, measurement instrumentation, and medical and industrial imaging.

  18. 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

  19. 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

  20. 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.

  1. Incorporating climate change projections into riparian restoration planning and design

    Science.gov (United States)

    Perry, Laura G.; Lindsay V. Reynolds; Beechie, Timothy J.; Collins, Mathias J.; Shafroth, Patrick B.

    2015-01-01

    Climate change and associated changes in streamflow may alter riparian habitats substantially in coming decades. Riparian restoration provides opportunities to respond proactively to projected climate change effects, increase riparian ecosystem resilience to climate change, and simultaneously address effects of both climate change and other human disturbances. However, climate change may alter which restoration methods are most effective and which restoration goals can be achieved. Incorporating climate change into riparian restoration planning and design is critical to long-term restoration of desired community composition and ecosystem services. In this review, we discuss and provide examples of how climate change might be incorporated into restoration planning at the key stages of assessing the project context, establishing restoration goals and design criteria, evaluating design alternatives, and monitoring restoration outcomes. Restoration planners have access to numerous tools to predict future climate, streamflow, and riparian ecology at restoration sites. Planners can use those predictions to assess which species or ecosystem services will be most vulnerable under future conditions, and which sites will be most suitable for restoration. To accommodate future climate and streamflow change, planners may need to adjust methods for planting, invasive species control, channel and floodplain reconstruction, and water management. Given the considerable uncertainty in future climate and streamflow projections, riparian ecological responses, and effects on restoration outcomes, planners will need to consider multiple potential future scenarios, implement a variety of restoration methods, design projects with flexibility to adjust to future conditions, and plan to respond adaptively to unexpected change.

  2. 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

  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. 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.

  5. 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 ...

  6. 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.

  7. 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.

  8. 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...

  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. 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 -...

  11. Resin composites

    DEFF Research Database (Denmark)

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

    2014-01-01

    OBJECTIVE: To investigate how the modulus of elasticity of resin composites influences marginal quality in restorations submitted to thermocyclic and mechanical loading. METHODS: Charisma, Filtek Supreme XTE and Grandio were selected as they were found to possess different moduli of elasticity but...... 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<0.0001). More paramarginal enamel fractures were observed after loading in teeth restored with Grandio when compared to Charisma (p=0.......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 be...

  12. 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.

  13. Restoration of bearings

    Science.gov (United States)

    Parker, R. J.; Zaretsky, E. V.; Hanau, H.

    1977-01-01

    Process consisting of grinding raceways to oversize but original quality condition and installing new oversize balls or bearings restores wornout ball and roller bearings to original quality, thereby doubling their operating life. Evaluations reveal process results in restoration of 90% of replaced bearings at less than 50% of new-bearing costs.

  14. Radio-opaque dental restorative material

    International Nuclear Information System (INIS)

    A radio-opaque composite material for use as a dental restorative is described which consists essentially of a conventional polymerizable resin binder and catalysts in admixture with a finely-divided inorganic filler capable of being coupled to the binder. The filler comprises a crystalline silicate containing barium in the crystalline composition. Calcium barium silicate in crystalline form is set forth in disclosing the best known mode for practicing the invention

  15. 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...... 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...... we introduce northern forests as an ecosystem, discuss the historical and recent human impact and provide a brief status report on the ecological restoration projects and research already conducted there. Based on this discussion, we argue that before any restoration actions commence, the ecology of...

  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. 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.

  18. Skjern River Restoration Counterfactual

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    In 2003 the Skjern River Restoration Project in Denmark was awarded the prestigious Europa Nostra Prize for ‘conserving the European cultural heritage’ (Danish Nature Agency 2005). In this case, however, it seems that the conservation of one cultural heritage came at the expense of another cultural...... the 1960s is perceived as a catalyst for the development of nature. As such the idea of the palimpsest might bring a valuable openness into the field of nature restoration rendering sites of nature restoration less like museums and more like laboratories. References: Clemmensen, T. J. (2014), ‘The...

  19. 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 ...

  20. 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.

  1. 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...

  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. Microleakage after Thermocycling of Three Self-Etch Adhesives under Resin-Modified Glass-Ionomer Cement Restorations

    OpenAIRE

    Gueders, Audrey M.; Albert, Adelin I.; Laurence Seidel; Geerts, Sabine O.

    2010-01-01

    This study was designed to evaluate microleakage that appeared on Resin-Modified Glass-Ionomer Cement (RMGIC) restorations. Sixty class V cavities (h×w×l=2 mm×2 mm×3 mm) were cut on thirty extracted third molars, which were randomly allocated to three experimental groups. All the buccal cavities were pretreated with polyacrylic acid, whereas the lingual cavities were treated with three one-step Self-Etch adhesives, respectively, Xeno...

  4. Microleakage of Three Types of Glass Ionomer Cement Restorations: Effect of CPP-ACP Paste Tooth Pretreatment

    OpenAIRE

    Maryam Doozandeh; Fereshteh Shafiei; Mostafa Alavi

    2015-01-01

    Statement of the Problem: Casein phosphopeptide–amorphous calcium phos-phate (CPP-ACP) increases the mineral content of tooth structure. This may enhance the chemical bonding of glass ionomer cements (GIC) and marginal sealing of their restorations. Purpose: The aim of this study was to evaluate the effect of CPP-ACP paste pretreatment on the microleakage of three types of GIC. Materials and Method: In this study, 72 Class V cavities were prepared on the buccal and lingual surfaces of m...

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

    Science.gov (United States)

    Khoroushi, Maryam; Sahraneshin-Samani, Mahsa

    2016-01-01

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

  6. 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

  7. 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

  8. 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...

  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. Radiopacity of dental restorative materials and cements

    International Nuclear Information System (INIS)

    The radiopacity of six composite resins, three resin luting cements and ten filling materials were studied. The purpose was to obtain an indication of radiopacity value of different brands within each of these groups of materials and to show differences in radiopacities of filling materials and natural tooth structures. On radiographs, the optimal densities of standardized samples were determined by computer imaging system and radiopacity values of the materials were expressed in millimeter equivalent aluminum. Within to groups of materials studied, there was considerable variation in radiopacity. The composite resins of P-50, Zl00 and prisma AP. H displayed much higher radiopacities than aluminum. Panavia resin cement was shown to be similarly radiopaque to aluminum. Generally, the radiopacity of base and filling materials appeared to combined applications for restorative treatment of teeth, lower radiopacity can interfere with the diagnosis and detection of gaps near the restoration.

  11. 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

  12. Restoration of contaminated soils

    International Nuclear Information System (INIS)

    A great variety of techniques are used for the restoration of contaminated soils. The contamination is present by both organic and inorganic pollutants. Environmental conditions and soil characteristics should take into account in order to implement a remedial technique. The bioremediation technologies are showed as help to remove a variety of soil contaminants. (author)

  13. 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...

  14. 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...

  15. 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.

  16. 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

  17. 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...

  18. 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.

  19. Upper Newport Bay Restoration Plan

    OpenAIRE

    Halsch, Chris; Wessling, Jaenna; Lister, Anne; Beck, Emily; Zembel, Richard; Yurko, Matt; Kimball, Sarah

    2016-01-01

    The overall goal of this restoration plan is to assist stakeholders in matching restoration projects with funding opportunities in order to increase the overall health of the Upper Newport Bay. Specifically, this document aims to assess current health and quality of native habitats in and around the bay, and to identify areas needing restoration. We have compiled data on the ecology of the bay, including extent of non-native plant invasion, restoration history and progress, site accessibility...

  20. Biologic Perspectives in Restorative Treatment

    OpenAIRE

    Savadi, Anupama; Rangarajan, V.; Savadi, Ravindra C.; Satheesh, Preeti

    2011-01-01

    One of the primary goals of a long term successful restorative therapy is to establish a physiologic periodontal climate that facilitates the maintenance of periodontal health. The contemporary clinician has a host of alternatives for the restoration of teeth. It is now possible to mimic nature and provide restorations that defy detection but the most challenging procedure in clinical dentistry is fabricating a restoration in gingival harmony. Periodontal health is the basis of all restorativ...

  1. 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...

  2. Ecological restoration: Biodiversity and conservation

    International Nuclear Information System (INIS)

    In this essay the principal concepts and methods applied on projects aimed at ecological restoration are reviewed, with emphasis on the relationship between conservation, biodiversity and restoration. The most common definitions are provided and the steps to take into account to develop projects on ecological restoration, which will be determined by the level of degradation of the ecosystem to be intervened.

  3. 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...

  4. Restoration of longitudinal images.

    Science.gov (United States)

    Hu, Y; Frieden, B R

    1988-01-15

    In this paper, a method of restoring longitudinal images is developed. By using the transfer function for longitudinal objects, and inverse filtering, a longitudinal image may be restored. The Fourier theory and sampling theorems for transverse images cannot be used directly in the longitudinal case. A modification and reasonable approximation are introduced. We have numerically established a necessary relationship between just-resolved longitudinal separation (after inverse filtering), noise level, and the taking conditions of object distance and lens diameter. An empirical formula is also found to well-fit the computed results. This formula may be of use for designing optical systems which are to image longitudinal details, such as in robotics or microscopy. PMID:20523607

  5. 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...

  6. 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…

  7. Inevitability of Balance Restoration

    OpenAIRE

    Oh, Man S.

    2010-01-01

    Prolonged imbalance between input and output of any element in a living organism is incompatible with life. The duration of imbalance varies, but eventually balance is achieved. This rule applies to any quantifiable element in a compartment of finite capacity. Transient discrepancies occur regularly, but given sufficient time, balance is always achieved, because permanent imbalance is impossible, and the mechanism for eventual restoration of balance is foolproof. The kidney is a central playe...

  8. Digital analysis and restoration of Daguerreotypes

    Science.gov (United States)

    Tang, Xiaoqing; Ardis, Paul A.; Messing, Ross; Brown, Christopher M.; Nelson, Randal C.; Ravines, Patrick; Wiegandt, Ralph

    2010-02-01

    George Eastman House International Museum of Photography Conservation Laboratory and the University of Rochester Department of Computer Science are researching image analysis techniques to distinguish daguerreotype plate and image features from deterioration, contaminant particulates, and optical imaging error occurring in high resolution photomicrography system. The images are captured at up to 30 times magnification and composited, including the ravages of age and reactivity of the highly polished surface that obscures and reduces the readability of the image. The University of Rochester computer scientists have developed and applied novel techniques for the seamless correction of a variety of problems. The final output is threefold: an analysis of regular artifacting resulting from imaging conditions and equipment; a fast automatic identification of problem areas in the original artifact; and an approximate digital restoration. In addition to the discussion of novel classification and restorative methods for digital daguerreotype restoration, this work highlights the effective use of large-scale parallelism for restoration (made available through the University of Rochester Center for Research Computing). This paper will show the application of analytical techniques to the Cincinnati Waterfront Panorama Daguerreotype, with the intent of making the results publically available through high resolution web image navigation tools.

  9. 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...

  10. Color stability evaluation of aesthetic restorative materials

    Directory of Open Access Journals (Sweden)

    Adriana Postiglione Bührer Samra

    2008-09-01

    Full Text Available Color match is one of the most important characteristics of aesthetic restorative materials. Maintenance of color throughout the functional lifetime of restorations is important for the durability of treatment. This characteristic is not constant among dental materials. The purpose of this research was to assess the color stability of five aesthetic restorative materials when immersed in a coffee solution. Seventy-one 17 mm x 1 mm specimens, divided into five groups, were made using one direct composite resin (Tetric Ceram®, Ivoclar/Vivadent - G1, three indirect composite resins (Targis, Ivoclar/Vivadent - G2; Resilab Master, Wilcos - G3; belleGlassTM HP, Kerr - G4 and one porcelain (IPS Empress® 2, Ivoclar/Vivadent - G5. The specimens were immersed in a coffee staining media for 15 days and stored under a controlled temperature of 37°C ± 1°C in the dark. The evaluations were made after 1, 7 and 15 days by means of reflectance spectrophotometry. The data was submitted to two-way ANOVA (p < 0.005 and post hoc tests. Statistical difference was observed between G1 / G3 and the other groups; G2 / G4 and the other groups; and G5 and all the other groups. It was concluded that G1 and G3 showed significantly higher discoloration than the other groups. G2 and G4 showed intermediary pigmentation, while G5 showed the smallest changes.

  11. Image restoration, uncertainty, and information.

    Science.gov (United States)

    Yu, F T

    1969-01-01

    Some of the physical interpretations about image restoration are discussed. From the theory of information the unrealizability of an inverse filter can be explained by degradation of information, which is due to distortion on the recorded image. The image restoration is a time and space problem, which can be recognized from the theory of relativity (the problem of image restoration is related to Heisenberg's uncertainty principle in quantum mechanics). A detailed discussion of the relationship between information and energy is given. Two general results may be stated: (1) the restoration of the image from the distorted signal is possible only if it satisfies the detectability condition. However, the restored image, at the best, can only approach to the maximum allowable time criterion. (2) The restoration of an image by superimposing the distorted signal (due to smearing) is a physically unrealizable method. However, this restoration procedure may be achieved by the expenditure of an infinite amount of energy. PMID:20072171

  12. 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.

  13. 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.

  14. 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.

  15. The phylogenetics of succession can guide restoration

    DEFF Research Database (Denmark)

    Shooner, Stephanie; Chisholm, Chelsea Lee; Davies, T. Jonathan

    2015-01-01

    Phylogenetic tools have increasingly been used in community ecology to describe the evolutionary relationships among co-occurring species. In studies of succession, such tools may allow us to identify the evolutionary lineages most suited for particular stages of succession and habitat...... phylogenetically random subset of species from the local species pool. Over time, there appears to be selection for particular lineages that come to be filtered across space and environment. The species most appropriate for mine site restoration might, therefore, depend on the successional stage of the community...... appropriate for mine site restoration might, therefore, depend on the successional stage of the community and the local species composition. For example, in later succession, it could be more beneficial to facilitate establishment of more distant relatives. Our findings can improve management practices by...

  16. 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.

  17. Complications in hair restoration.

    Science.gov (United States)

    Lam, Samuel M

    2013-11-01

    Hair restoration requires a high level of specialized skill on the part of both the surgeon and the assistant team. Recipient-site problems can manifest from either surgeon or assistant error. The surgeon can create an unnatural hairline due to lack of knowledge of natural hair-loss patterns or badly executed recipient sites. He must also be cognizant of how hairs naturally are angled on the scalp to re-create a pattern that appears natural when making recipient sites. Assistants can also greatly contribute to the success or failure of surgery in their task of graft dissection and graft placement. PMID:24200385

  18. Robotic hair restoration.

    Science.gov (United States)

    Rose, Paul T; Nusbaum, Bernard

    2014-01-01

    The latest innovation to hair restoration surgery has been the introduction of a robotic system for harvesting grafts. This system uses the follicular unit extraction/follicular isolation technique method for harvesting follicular units, which is particularly well suited to the abilities of a robotic technology. The ARTAS system analyzes images of the donor area and then a dual-chamber needle and blunt dissecting punch are used to harvest the follicular units. The robotic technology is now being used in various locations around the world. This article discusses the use of the robotic system, its capabilities, and the advantages and disadvantages of the system. PMID:24267426

  19. Color Texture Restoration

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Havlíček, Vojtěch

    445 Hoes Lane, Piscataway, NJ 08854, USA: IEEE, 2015, s. 13-18. ISBN 978-1-4673-7337-1. [7th IEEE International Conferences on Cybernetics and Intelligent Systems (CIS), and Robotics , Automation and Mechatronics (RAM). Siem Reap (KH), 17.07.2015-17.07.2015] R&D Projects: GA ČR(CZ) GA14-10911S Institutional support: RVO:67985556 Keywords : Texture restoration * Gaussian mixture model Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2015/RO/haindl-0446068.pdf

  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)

    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. The future of the restoration

    OpenAIRE

    Verhoef, L.G.W.

    2001-01-01

    The title 'The Future of Restoration' implies that there is a future lor restoration. Putting this even more strongly, the future of restoration is becoming increasingly important. Not only are monuments our witnesses to the past but these witnesses have much to tell about the organisation of life of work in the past, about how structures were built and about kinds of techniques and materials that were used. Lessons have often been learnt in the hard way because many buildings have been lost ...

  6. 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...

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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

  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. 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

  14. SOCIAL WELFARE AND RESTORATIVE JUSTICE

    OpenAIRE

    Darrell Fox

    2009-01-01

    "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." [author's abstract

  15. 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.

  16. 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…

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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...

  2. [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

  3. Avaliação in vitro da microinfiltração em cavidades de classe V restauradas com diferentes combinações de resina composta e cimento de ionômero de vidro

    Directory of Open Access Journals (Sweden)

    ZANATA Régia Luzia

    1998-01-01

    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.

  4. Fernald restoration: ecologists and engineers integrate restoration and cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Woods, Eric; Homer, John

    2002-07-15

    As cleanup workers excavate pits and tear down buildings at the Fernald site in southwest Ohio, site ecologists are working side-by-side to create thriving wetlands and develop the early stages of forest, prairie, and savanna ecosystems to restore natural resources that were impacted by years of site operations. In 1998, the U.S. Department of Energy-Fernald Office (DOE-FN) and its cleanup contractor, Fluor Fernald, Inc., initiated several ecological restoration projects in perimeter areas of the site (e.g., areas not used for or impacted by uranium processing or waste management). The projects are part of Fernald's final land use plan to restore natural resources over 904 acres of the 1,050-acre site. Pete Yerace, the DOE-FN Natural Resource Trustee representative is working with the Fernald Natural Resource Trustees in an oversight role to resolve the state of Ohio's 1986 claim against DOE for injuries to natural resources. Fluor Fernald, Inc., and DOE-FN developed the ''Natural Resource Restoration Plan'', which outlines 15 major restoration projects for the site and will restore injured natural resources at the site. In general, Fernald's plan includes grading to maximize the formation of wetlands or expanded floodplain, amending soil where topsoil has been removed during excavation, and establishing native vegetation throughout the site. Today, with cleanup over 35 percent complete and site closure targeted for 2006, Fernald is entering a new phase of restoration that involves heavily remediated areas. By working closely with engineers and cleanup crews, site ecologists can take advantage of remediation fieldwork (e.g., convert an excavated depression into a wetland) and avoid unnecessary costs and duplication. This collaboration has also created opportunities for relatively simple and inexpensive restoration of areas that were discovered during ongoing remediation. To ensure the survival of the plant material in heavily

  5. The restoration of traumatized teeth.

    Science.gov (United States)

    Liddelow, G; Carmichael, G

    2016-03-01

    The restoration of a traumatized tooth may require minimally invasive or more extensive treatment options. The majority of injuries occur in the younger population, so management should consider the long-term outcome, failure and future treatment needs over the course of, often, many decades. The aim should be to provide a tooth-restoration complex that closely mimics the functional and aesthetic qualities of an intact tooth for as long as possible. This narrative review will assess the relevant literature pertinent to restoration of traumatized teeth in order to provide guidance for the practising clinician. PMID:26923452

  6. River Restoration Data in Lamoille County, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Documented river and riparian buffer restoration projects in Lamoille County, Vermont. Restoration includes buffer plantings (trees and shrubs), bank stabilization...

  7. Effect of residual monomer on the strength of restorative resins

    International Nuclear Information System (INIS)

    Quantity of the remaining unreacted double bonds within the free monomers influences the mechanical and physical properties of restorative resins. Clinically, the residual monomer may result in unfavorable biologic symptoms. Five proprietary composite resins were investigated using infrared spectrophotometry. The change in the monomer content was monitored through the change in absorbance of the C-C bond resonating at 1640 centi meter during the polymerization reaction at 37 degree C. The materials investigated under conditions comparable with optimal clinical circumstance, showed values of residual monomer ranging from 6% to 43%. The diametral tensile strength has decreased as the quantity of residual monomer has increased in a simple linear relationship. The final properties of a dental composite restorative material are directly related both to the chemical composition of the monomer system and the degree of conversion to polymer which has occurred. (author)

  8. Kondolf Diagram for River Restoration

    Science.gov (United States)

    Rehabilitation, protection, and management of riverine backwaters (floodplain aquatic habitats that are seasonally or periodically connected to the main channel) are becoming increasingly common. General criteria for selecting restoration goals and evaluating alternative designs are lacking. An app...

  9. Basic research for environmental restoration

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) is in the midst of a major environmental restoration effort to reduce the health and environmental risks resulting from past waste management and disposal practices at DOE sites. This report describes research needs in environmental restoration and complements a previously published document, DOE/ER-0419, Evaluation of Mid-to-Long Term Basic Research for Environmental Restoration. Basic research needs have been grouped into five major categories patterned after those identified in DOE/ER-0419: (1) environmental transport and transformations; (2) advanced sampling, characterization, and monitoring methods; (3) new remediation technologies; (4) performance assessment; and (5) health and environmental effects. In addition to basic research, this document deals with education and training needs for environmental restoration. 2 figs., 6 tabs

  10. Basic research for environmental restoration

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

    The Department of Energy (DOE) is in the midst of a major environmental restoration effort to reduce the health and environmental risks resulting from past waste management and disposal practices at DOE sites. This report describes research needs in environmental restoration and complements a previously published document, DOE/ER-0419, Evaluation of Mid-to-Long Term Basic Research for Environmental Restoration. Basic research needs have been grouped into five major categories patterned after those identified in DOE/ER-0419: (1) environmental transport and transformations; (2) advanced sampling, characterization, and monitoring methods; (3) new remediation technologies; (4) performance assessment; and (5) health and environmental effects. In addition to basic research, this document deals with education and training needs for environmental restoration. 2 figs., 6 tabs.

  11. Papahanaumokuakea - Laysan Island Restoration 2009

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This project will support restoration activities at Laysan Island. Staff and volunteers continue efforts to eradicate alien invasive species such as Indian dropseed...

  12. Papahanaumokuakea - Laysan Island Restoration 2011

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This project supports restoration activities at Laysan Island. Staff and volunteers continue efforts to eradicate alien invasive species such as Indian dropseed...

  13. Casting and Mechanized Titanium Restorations

    OpenAIRE

    Madrigal, A.; Lopez, I; Suarez, MJ; Salido, MP.

    2002-01-01

    INTRODUCTION: New materials and methods for clinical dentistry are continuously being introduced. There is a growing interest in the use of titanium as a restorative material for several reasons: its relatively low cost, favorable physical properties and biocompatibility. However, titanium is technically more difficult to handle than conventional metal alloys. There are two fabrication methods for titanium restorations: casting and mechanized (a combination of machine duplication and spark er...

  14. Factors affecting the placement or replacement of direct restorations in a dental school

    Directory of Open Access Journals (Sweden)

    Samara Silvani

    2014-01-01

    Full Text Available Context: The knowledge of the reasons for the placement of direct restorations makes possible to trace an epidemiological profile of a specific population and to direct the teaching of dentistry to techniques that are commonly used today and will be continued performed in the future. Purpose: The aim of this study was to verify the reasons for placement and replacement of direct restorations in patients treated in the Dental Clinic of the Uberaba University - Brazil. Materials and Methods: This study evaluated 306 restorative procedures carried out on 60 patients. During the treatment planning, a form that contained information about the patient′s gender, tooth number, the classification of restorations, the reasons for placement and replacement of amalgam and tooth-colored restorations, the material that had to be removed and the new material used to fill the cavities was filled for each patient. Statistical analysis was carried out using Chi-square test (α = 0.05. Results: The data showed that most of the patients were female (66.7%. Of all the restorations placed, 60.45% were 1 st -time placements, while 39.55% were replacements. For 1 st -time restorations, the main reason for placement was primary caries (76.76%, followed by non-carious cervical lesions (15.14%. The amalgam restorations were replaced more frequently (67.77%. The primary reason for replacements was the presence of secondary caries (for both previous amalgam (42.68% and composite (66.67% restorations (P < 0.05. The resin composite was the most indicated material for the new restorations (98.04% (P < 0.05. Conclusions: The main reason for placement of direct restorations was primary caries, while secondary caries was the main reason for replacements. In almost all cases, the material used to fill the cavities was the resin composite.

  15. CAD/CAM全瓷嵌体与复合树脂嵌体修复后牙II类洞临床疗效对比分析%Comparison of clinical efficacy of CAD/CAM all-ceramic inlay and composite resin inlay in restoration of posterior ClassⅡcavity

    Institute of Scientific and Technical Information of China (English)

    董丽平; 孙璐; 杨洋; 陈丽娜; 尚丹丹

    2014-01-01

    Objective:To compare the clinical efficacy of CAD/CAM all-ceramic inlay and composite resin inlay in restoring ClassⅡcavity of posterior teeth. Methods:226 posterior teeth of ClassⅡcavity from 193 patients were recruited in our clinical trial. 101 teeth of the selected teeth were restored with CAD/CAM all-ceramic inlays, and the rest was restored by composite resin inlays. Prosthesis abrasion, prosthesis fracture, prosthesis off, marginal adapta-tion, edge coloring, and secondary caries of the two groups were evaluated during 6-month, 12-month and 18-month follow-up appointments, respectively. Results: There were significant differences in prosthesis abrasion and edge coloring between the two groups (P0.05). The success rate of CAD/CAM all-ceramic inlay is 96.84%, and the composite resin inlay is 81.05%. There was significant difference between the success rates (P<0.05). Conclusion:The efficacy of CAD/CAM all-ceramic inlay is better than that of composite resin inlay during the treatment of the posterior ClassⅡcavities.%目的:对比分析CAD/CAM全瓷嵌体与复合树脂嵌体修复后牙Ⅱ类洞的临床疗效。方法:选择在解放军总医院口腔内科就诊的后牙Ⅱ类洞患者193例(共226颗牙),根据患者意愿,其中101颗采用CAD/CAM全瓷嵌体修复,其余125颗采用复合树脂嵌体修复,分别在术后6个月、12个月、18个月进行随访,观察其修复体磨耗、折裂、脱落、边缘密合性、边缘着色及继发龋等情况。结果:2种嵌体在修复体磨耗及边缘着色的差异有统计学意义(P<0.05),在修复体折裂、修复体脱落、继发龋和边缘密合性的差异无统计学意义(P>0.05)。 CAD/CAM 全瓷嵌体的成功率为:96.84%,树脂嵌体的成功率为:81.05%,两组之间成功率的差异有统计学意义(P<0.05)。结论:在后牙Ⅱ类洞缺损的修复治疗中, CAD/CAM全瓷嵌体的效果优于复合树脂嵌体。

  16. Restoring force method and response estimation

    International Nuclear Information System (INIS)

    The restoring force method is briefly outlined. Signal modifications that are necessary to successfully determine restoring force functions are discussed and illustrated. Restoring force functions for a base and a force excited system were determined and their effectiveness demonstrated by comparing measured and predicted signals. Additional developments that would make the restoring force method more general are suggested. 5 refs., 12 figs

  17. Ecological restoration of farmland: progress and prospects

    OpenAIRE

    Wade, Mark R.; Gurr, Geoff M.; Wratten, Steve D

    2007-01-01

    Sustainable agricultural practices in conjunction with ecological restoration methods can reduce the detrimental effects of agriculture. The Society for Ecological Restoration International has produced generic guidelines for conceiving, organizing, conducting and assessing ecological restoration projects. Additionally, there are now good conceptual frameworks, guidelines and practical methods for developing ecological restoration programmes that are based on sound ecological principles and s...

  18. Technical approach to groundwater restoration

    International Nuclear Information System (INIS)

    The Technical Approach to Groundwater Restoration (TAGR) provides general technical guidance to implement the groundwater restoration phase of the Uranium Mill Tailings Remedial Action (UMTRA) Project. The TAGR includes a brief overview of the surface remediation and groundwater restoration phases of the UMTRA Project and describes the regulatory requirements, the National Environmental Policy Act (NEPA) process, and regulatory compliance. A section on program strategy discusses program optimization, the role of risk assessment, the observational approach, strategies for meeting groundwater cleanup standards, and remedial action decision-making. A section on data requirements for groundwater restoration evaluates the data quality objectives (DQO) and minimum data required to implement the options and comply with the standards. A section on sits implementation explores the development of a conceptual site model, approaches to site characterization, development of remedial action alternatives, selection of the groundwater restoration method, and remedial design and implementation in the context of site-specific documentation in the site observational work plan (SOWP) and the remedial action plan (RAP). Finally, the TAGR elaborates on groundwater monitoring necessary to evaluate compliance with the groundwater cleanup standards and protection of human health and the environment, and outlines licensing procedures

  19. Ceramics in Restorative and Prosthetic DENTISTRY1

    Science.gov (United States)

    Kelly, J. Robert

    1997-08-01

    This review is intended to provide the ceramic engineer with information about the history and current use of ceramics in dentistry, contemporary research topics, and potential research agenda. Background material includes intra-oral design considerations, descriptions of ceramic dental components, and the origin, composition, and microstructure of current dental ceramics. Attention is paid to efforts involving net-shape processing, machining as a forming method, and the analysis of clinical failure. A rationale is presented for the further development of all-ceramic restorative systems. Current research topics receiving attention include microstructure/processing/property relationships, clinical failure mechanisms and in vitro testing, wear damage and wear testing, surface treatments, and microstructural modifications. The status of the field is critically reviewed with an eye toward future work. Significant improvements seem possible in the clinical use of ceramics based on engineering solutions derived from the study of clinically failed restorations, on the incorporation of higher levels of "biomimicry" in new systems, and on the synergistic developments in dental cements and adhesive dentin bonding.

  20. Governing Forest Landscape Restoration : Cases from Indonesia

    OpenAIRE

    Oosten, van, T.; Gunarso, P.; Koesoetjahjo, I.; Wiersum, F.

    2014-01-01

    Forest landscape restoration includes both the planning and implementation of measures to restore degraded forests within the perspective of the wider landscape. Governing forest landscape restoration requires fundamental considerations about the conceptualisation of forested landscapes and the types of restoration measures to be taken, and about who should be engaged in the governance process. A variety of governance approaches to forest landscape restoration exist, differing in both the nat...

  1. Fracture resistance of bleached teeth restored with different procedures

    Directory of Open Access Journals (Sweden)

    Matheus Coelho Bandéca

    2012-08-01

    Full Text Available This study evaluated the fracture resistance of teeth submitted to internal bleaching and restored with different non-metallic post. Eighty mandibular incisors were endodontically treated and randomly divided in 10 groups (n = 8: G1- restored with composite resin (CR, G2- CR + fiber-reinforced composite post (FRC, Everstick post, Sticktech cemented with resin cement self-etch adhesive (RCS, Panavia F 2.0, Kuraray, G3- CR + FRC + self-adhesive resin cement (SRC, Breeze, Pentral Clinical, G4- CR+ glass fiber post (GF, Exacto Post, Angelus + RCS, G5- CR + GF + SRC. The G6 to G10 were bleached with hydrogen peroxide (HP and restored with the same restorative procedures used for G1 to G5, respectively. After 7 days storage in artificial saliva, the specimens were submitted to the compressive strength test (N at 0.5 mm/min cross-head speed and the failure pattern was identified as either reparable (failure showed until 2 mm below the cement-enamel junction or irreparable (the failure showed <2 mm or more below the cement-enamel. Data were analyzed by ANOVA and Tukey test (α = 0.05. No significant difference (p < 0.05 was found among G1 to G10. The results suggest that intracoronal bleaching did not significantly weaken the teeth and the failure patterns were predominately reparable for all groups. The non-metallic posts in these teeth did not improve fracture resistance.

  2. The Importance of the Regional Species Pool, Ecological Species Traits and Local Habitat Conditions for the Colonization of Restored River Reaches by Fish

    OpenAIRE

    Stoll, Stefan; Kail, Jochem; Lorenz, Armin W.; Sundermann, Andrea; Haase, Peter

    2014-01-01

    It is commonly assumed that the colonization of restored river reaches by fish depends on the regional species pools; however, quantifications of the relationship between the composition of the regional species pool and restoration outcome are lacking. We analyzed data from 18 German river restoration projects and adjacent river reaches constituting the regional species pools of the restored reaches. We found that the ability of statistical models to describe the fish assemblages established ...

  3. Analysis of the Engineering Restoration Effect of Abandoned Yongledian Quarry in Beijing City Based on Soil Physical and Chemical Properties

    Institute of Scientific and Technical Information of China (English)

    Liwei; CAI

    2014-01-01

    The improvement of the soil physical and chemical properties is the most important foundation for mine ecological restoration.The experiment is aimed at undisturbed area,restored area,and damaged area of abandoned Yongledian Quarry in Beijing.Through determination and analysis of soil physical and chemical properties,it shows that there are significant differences in the composite effects of soil physical and chemical properties between restored area,and undisturbed area,damaged area,and engineering restoration effectively improves the composite effects of soil physical and chemical properties in the restored area.The single factor hypothesis test shows that soil pH value,organic matter,alkali-hydrolyzable nitrogen,and total nitrogen traits are the key targets to be restored in this mining area.

  4. Phonemic restoration in developmental dyslexia.

    Science.gov (United States)

    Del Tufo, Stephanie N; Myers, Emily B

    2014-01-01

    The comprehension of fluent speech in one's native language requires that listeners integrate the detailed acoustic-phonetic information available in the sound signal with linguistic knowledge. This interplay is especially apparent in the phoneme restoration effect, a phenomenon in which a missing phoneme is "restored" via the influence of top-down information from the lexicon and through bottom-up acoustic processing. Developmental dyslexia is a disorder characterized by an inability to read at the level of one's peers without any clear failure due to environmental influences. In the current study we utilized the phonemic restoration illusion paradigm to examine individual differences in phonemic restoration across a range of reading ability, from very good to dyslexic readers. Results demonstrate that restoration occurs less in those who have high scores on measures of phonological processing. Based on these results, we suggest that the processing or representation of acoustic detail may not be as reliable in poor and dyslexic readers, with the result that lexical information is more likely to override acoustic properties of the stimuli. This pattern of increased restoration could result from a failure of perceptual tuning, in which unstable representations of speech sounds result in the acceptance of non-speech sounds as speech. An additional or alternative theory is that degraded or impaired phonological processing at the speech sound level may reflect architecture that is overly plastic and consequently fails to stabilize appropriately for speech sound representations. Therefore, the inability to separate speech and noise may result as a deficit in separating noise from the acoustic signal. PMID:24926230

  5. Effect of Different Surface Treatments on the Bond Strength of Repaired Resin Restorations

    International Nuclear Information System (INIS)

    In the last decade, growing demands by patients for mercury-free esthetic restorations had markedly increased the use of resin composites in restorative dentistry. However, despite the continuing development of resin composites with improved properties, several factors, such as discoloration, color mismatch, wear; chipping or bulk fracture might present clinical problems (Mjor and Gordan. 2002, Vichi et al. 2004 and Kolbeck et al. 2006). As a result, the clinician should decide whether to replace or simply repair these restorations. Total replacement of the restoration might be regarded as over-treatment since in most cases, large portions of the restorations might be clinically and radio graphically considered free of failure. Moreover, complete removal of the restoration inevitably resulted in weakening of the tooth, unnecessary removal of intact dental tissues, more money and time consuming. For these reasons, the repair of the restoration instead of its removal would be a favorable procedure (Lucena-Martin et al. 2001, Frankenberger et al. 2003 a and Oztas et al. 2003). The key element in the determination of successful repair procedures was the adequate bond strength between the existing resin composite and the new one. Various methods have been suggested to improve the bond strength of the repaired resin restorations (Tezvergil et al. 2003 and Bonstein et al. 2005). Mechanical and/or chemical treatments had been investigated for preparation of the aged resin restorations to be repaired (Tezvergil et al. 2003, Ozcan et al. 2005 and Hannig et al. 2006). These treatments were introduced to counteract the problems of aged resin restorations which were limited amount of residual free radicals available for reaction with the repair material, contaminated surface, and highly cross-linked resin matrix ( Dall Oca et al. 2006 and Papacchini et al. 2007 a) Previous studies emphasized that mechanical treatments are the most important factor in obtaining optimal repair

  6. Image restoration fundamentals and advances

    CERN Document Server

    Gunturk, Bahadir Kursat

    2012-01-01

    Image Restoration: Fundamentals and Advances responds to the need to update most existing references on the subject, many of which were published decades ago. Providing a broad overview of image restoration, this book explores breakthroughs in related algorithm development and their role in supporting real-world applications associated with various scientific and engineering fields. These include astronomical imaging, photo editing, and medical imaging, to name just a few. The book examines how such advances can also lead to novel insights into the fundamental properties of image sources. Addr

  7. Flowable resin and marginal gap on tooth third medial cavity involving enamel and radicular cementum: A SEM evaluation of two restoration techniques

    Directory of Open Access Journals (Sweden)

    G Lo Giudice

    2012-01-01

    Conclusion: The interposition of a low elastic modulus composite between the adhesive layer and the composite resin allows an improvement of the cementum-restoration interface by the means of a lower shrinkage stress during polymerization.

  8. Effects of Restoration Techniques on Soil Carbon and Nitrogen Dynamics in Florida Longleaf Pine (Pinus palustris) Sandhill Forests

    OpenAIRE

    Martin Lavoie; Mack, Michelle C; John K. Hiers; Scott Pokswinski; Analie Barnett; Louis Provencher

    2014-01-01

    Historic fire suppression and intensive forest management in longleaf pine (Pinus palustris) sandhill forests has resulted in hardwood encroachment and degradation of this fire-dependent ecosystem. Active management is now required to restore native community structure and composition, but little is known about the long-term impacts of typical restoration techniques on ecosystem properties. In 1994, the Longleaf Pine Restoration Project (LPRP) was established in fire-excluded longleaf pine sa...

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  10. 不同纤维桩修复方式影响重度楔状缺损前磨牙的抗折性能%Fracture resistance ability of severe wedge-shaped premolar defects restored with fiber reinforced composite post by different methods

    Institute of Scientific and Technical Information of China (English)

    沈晴昳; 李国强; 张强; 翁蓓军; 翁佳炜

    2014-01-01

    , which was restored with fiber reinforced composite posts by different therapy methods. METHODS:A total of 50 human maxilary premolars were randomly divided into five groups, with ten teeth in each group. They were given folowing treatments: Group A: 10 untreated premolars; Rest 40 premolars of Groups B, C, D and E were prepared 1/3 bucco-lingual distance for artificial severe wedge-shaped defects at the buccal cervix. Group B: untreated severe wedge-shaped defects premolars; Group C: severe wedge-shaped defects premolars were endodonticaly treated, remaining dentin over hang above the wedge shaped defect, LuxaPost posts reinforced in buccal canal and lingual canal, LuxaCore composite resin restored dentin defect; Group D: severe wedge-shaped defects premolars were endodonticaly treated, LuxaPost posts reinforced in buccal canal and lingual canal, LuxaCore composite resin restored dentin defect, and then covered with ful metal crown; Group E: severe wedge-shaped defects premolars were endodonticaly treated, removing dentin over hang above the wedge shaped defect, LuxaPost posts reinforced in buccal canal and lingual canal, restored with LuxaCore composite resin, and then covered with ful metal crown. Fracture resistance of each specimen was measured in each group. RESULTS AND CONCLUSION: The fracture strength of each group were Group A (1 002.69±147.62) N, Group B (439.28±66.34) N, Group C (958.30±101.23) N, Group D (1 207.09±143.48) N, and Group E (1 056.44±139.30) N. Group D had the highest fracture strength (P < 0.01), while Group B had the lowest fracture strength (P < 0.01). There were no significant difference among the fracture strength of Group A, Group C and Group E. Our findings indicated that the fracture resistance of the severe wedge-shaped defected premolar can be improved by fiber reinforced composite post and dentin above wedge shaped defect remained.

  11. Advances and challenges in hair restoration of curly Afrocentric hair.

    Science.gov (United States)

    Rogers, Nicole E; Callender, Valerie D

    2014-04-01

    Although the biochemical composition of hair is similar among racial and ethnic groups, the hair structure between them varies, and individuals with curly hair pose specific challenges and special considerations when a surgical option for alopecia is considered. Hair restoration in this population should therefore be approached with knowledge on the clinical characteristics of curly hair, hair grooming techniques that may influence the management, unique indications for the procedure, surgical instrumentation used, and the complications that may arise. PMID:24680003

  12. Determination of mode of fracture of adhesive restorative materials. An invitro study.

    OpenAIRE

    Nayak Ullal; Suasha P

    2002-01-01

    In the present invitro study, four adhesive restorative materials were evaluated for the determination of mode of fracture. The four materials chosen were TPH composite resin, Dyract, Fuji II LC and Fuji II. The mode of fracture was determined at a magnification of 10X. The TPH composite resin and Dyract showed adhesive fracture whereas the glass ionomer group showed cohesive fracture.

  13. Forensics image and video restoration

    Czech Academy of Sciences Publication Activity Database

    Zitová, Barbara; Šroubek, Filip; Kamenický, Jan; Kotera, Jan; Šorel, Michal; Bartoš, Michal; Flusser, Jan; Šíma, Z.; Švarc, P.; Hořínek, J.

    Praha: Institute of Criminalistics Prague, 2015. EAFS-0743. [European Academy of Forensic Science Conference 2015 /7./. 06.09.2015-11.09.2015, Praha] R&D Projects: GA MV VG20102013064 Institutional support: RVO:67985556 Keywords : image restoration * image forensics Subject RIV: JD - Computer Applications, Robotics http://library.utia.cas.cz/separaty/2015/ZOI/zitova-0450637.pdf

  14. Bayesian image restoration, using configurations

    DEFF Research Database (Denmark)

    Thorarinsdottir, Thordis Linda

    2006-01-01

    configurations are expressed in terms of the mean normal measure of the random set. These probabilities are used as prior probabilities in a Bayesian image restoration approach. Estimation of the remaining parameters in the model is outlined for the salt and pepper noise. The inference in the model is discussed...

  15. Bayesian image restoration, using configurations

    DEFF Research Database (Denmark)

    Thorarinsdottir, Thordis

    configurations are expressed in terms of the mean normal measure of the random set. These probabilities are used as prior probabilities in a Bayesian image restoration approach. Estimation of the remaining parameters in the model is outlined for salt and pepper noise. The inference in the model is discussed in...

  16. Zirconia-reinforced dental restorations

    NARCIS (Netherlands)

    C. Chen

    2013-01-01

    The series of studies conducted in this thesis showed that there are several ways to enhance the performance of fixed restorations regarding the application of zirconia. One possible way is to change the sintering procedure of zirconia, so that the physical properties of zirconia such BFS, density o

  17. A review on anterior teeth restorations

    Directory of Open Access Journals (Sweden)

    Gaurav Solanki

    2014-12-01

    Full Text Available Restorations of teeth have been a need of time since very long. As the time have passed, there have been different advances in the field of restorative materials and tooth restorations. Many newer restorative materials are now available to us for the purpose of tooth restorations still some of the older materials are materials of choice for a sector of society. This article focuses on few such restorative materials and also tells us about a few patents granted in such field.

  18. Effect of three surface conditioning methods to improve bond strength of particulate filler resin composites

    OpenAIRE

    M. Özcan; Alander, P.; Vallittu, P K; Huysmans, M.C.; Kalk, W

    2004-01-01

    The use of resin-based composite materials in operative dentistry is increasing, including applications in stress-bearing areas. However, composite restorations, in common with all restorations, suffer from deterioration and degradation in clinical service. Durable repair alternatives by layering a new composite onto such failed composite restorations, will eliminate unnecessary loss of tooth tissue and repeated insults to the pulp. The objective of this study was to evaluate the effect of th...

  19. Phonemic restoration in developmental dyslexia

    Directory of Open Access Journals (Sweden)

    Stephanie N. Del Tufo

    2014-06-01

    Full Text Available The comprehension of fluent speech in one’s native language requires that listeners integrate the detailed acoustic-phonetic information available in the sound signal with linguistic knowledge. This interplay is especially apparent in the phoneme restoration effect, a phenomenon in which a missing phoneme is ‘restored’ via the influence of top-down information from the lexicon and through bottom-up acoustic processing. Developmental dyslexia is a disorder characterized by an inability to read at the level of one’s peers without any clear failure due to environmental influences. In the current study we utilized the phonemic restoration illusion paradigm, to examine individual differences in phonemic restoration across a range of reading ability, from very good to dyslexic readers. Results demonstrate that restoration occurs less in those who have high scores on measures of phonological processing. Based on these results, we suggest that the processing or representation of acoustic detail may not be as reliable in poor and dyslexic readers, with the result that lexical information is more likely to override acoustic properties of the stimuli. This pattern of increased restoration could result from a failure of perceptual tuning, in which unstable representations of speech sounds result in the acceptance of non-speech sounds as speech. An additional or alternative theory is that degraded or impaired phonological processing at the speech sound level may reflect architecture that is overly plastic and consequently fails to stabilize appropriately for speech sound representations. Therefore the inability to separate speech and noise may result as a deficit in separating noise from the acoustic signal.

  20. Seed dispersal limitations shift over time in tropical forest restoration.

    Science.gov (United States)

    Reid, J Leighton; Holl, Karen D; Zahawi, Rakan A

    2015-06-01

    Past studies have shown that tropical forest regeneration on degraded farmlands is initially limited by lack of seed dispersal, but few studies have tracked changes in abundance and composition of seed rain past the first few years after land abandonment. We measured seed rain for 12 months in 10 6-9-year-old restoration sites and five mature, reference forests in southern Costa Rica in order to learn (1) if seed rain limitation persists past the first few years of regeneration; (2) how restoration treatments influence seed community structure and composition; and (3) whether seed rain limitation is contingent on landscape context. Each restoration site contained three 0.25-ha treatment plots: (1) a naturally regenerating control, (2) tree islands, and (3) a mixed-species tree plantation. Sites spanned a deforestation gradient with 9-89% forest area within 500 m around the treatment plots. Contrary to previous studies, we found that tree seeds were abundant and ubiquitous across all treatment plots (585.1 ± 142.0 seeds · m(-2) · yr(-1) [mean ± SE]), indicating that lack of seed rain ceased to limit forest regeneration within the first decade of recovery. Pioneer trees and shrubs comprised the vast majority of seeds, but compositional differences between restoration sites and reference forests were driven by rarer, large-seeded species. Large, animal-dispersed tree seeds were more abundant in tree islands (4.6 ± 2.9 seeds · m(-2) · yr(-1)) and plantations (5.8 ± 3.0 seeds · m(-2) · yr(-1)) than control plots (0.2 ± 0.1 seeds · m(-2) · yr(-1)), contributing to greater tree species richness in actively restored plots. Planted tree species accounted for seeds. We found little evidence for landscape forest cover effects on seed rain, consistent with previous studies. We conclude that seed rain limitation shifted from an initial, complete lack of tree seeds to a specific limitation on large-seeded, mature forest species over the first decade. Although total

  1. Lock-in thermography, penetrant inspection, and scanning electron microscopy for quantitative evaluation of open micro-cracks at the tooth-restoration interface

    Science.gov (United States)

    Streza, M.; Hodisan, I.; Prejmerean, C.; Boue, C.; Tessier, Gilles

    2015-03-01

    The evaluation of a dental restoration in a non-invasive way is of paramount importance in clinical practice. The aim of this study was to assess the minimum detectable open crack at the cavity-restorative material interface by the lock-in thermography technique, at laser intensities which are safe for living teeth. For the analysis of the interface, 18 box-type class V standardized cavities were prepared on the facial and oral surfaces of each tooth, with coronal margins in enamel and apical margins in dentine. The preparations were restored with the Giomer Beautifil (Shofu) in combination with three different adhesive systems. Three specimens were randomly selected from each experimental group and each slice has been analysed by visible, infrared (IR), and scanning electron microscopy (SEM). Lock-in thermography showed the most promising results in detecting both marginal and internal defects. The proposed procedure leads to a diagnosis of micro-leakages having openings of 1 µm, which is close to the diffraction limit of the IR camera. Clinical use of a thermographic camera in assessing the marginal integrity of a restoration becomes possible. The method overcomes some drawbacks of standard SEM or dye penetration testing. The results support the use of an IR camera in dentistry, for the diagnosis of micro-gaps at bio-interfaces.

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

    Directory of Open Access Journals (Sweden)

    Mahtab Memarpour

    2016-01-01

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

  3. In vivo Evaluation of Enamel Dental Restoration Interface by Optical Coherence Tomography

    International Nuclear Information System (INIS)

    In this work, we report in vivo application of Optical Coherence Tomography (OCT) to assess dental restorations in humans. After approval by the Ethical Committee in Humans Research of the Federal University of Pernambuco, thirty patients with resin composite restorations performed in anterior teeth were selected. The patients were clinically evaluated, and OCT was performed. Images were obtained using OCT operating in the spectral domain, with a 840 nm super luminescent diode light source (spectral width of 50 nm, fiber output power 25mW and a measured spatial resolution of 10 μm). The image acquisition time was less than one second. The results were analyzed with respect to the integrity and marginal adaptation of the restoration. Using appropriate software, the lesion region can be exactly located and a new restoration procedure can be carried out. We have shown that OCT is more than adequate in clinical practice to assess dental restorations. (Author)

  4. Fracture strength and stress distributions of pulpless premolars restored with fiber posts.

    Science.gov (United States)

    Furuya, Yu; Huang, Shih-Hao; Takeda, Yuko; Fok, Alex; Hayashi, Mikako

    2014-01-01

    This study examined the effect of glass fiber posts on increasing the fracture resistance of endodontically treated teeth. Extracted upper premolars with two canals in a root were divided into three groups according to the number of posts they were restored with: none, one, or two. All teeth were endodontically treated, crown-sectioned, and restored with a composite core and a metallic crown. A static oblique load was applied to the restored tooth until fracture, and the fracture pattern was recorded. Stress distributions were examined by finite element analysis (FEA). Teeth with glass fiber post(s) showed significantly higher fracture loads compared with those without posts. In the premolars without posts, von Mises and maximum principal stresses were found on the root surface alone; in premolars restored with posts, stresses were distributed on both root and post surfaces. Risk of root dentin fracture was significantly lowest in teeth restored with two posts. PMID:25483385

  5. Utilizing optical coherence tomography for CAD/CAM of indirect dental restorations

    Science.gov (United States)

    Chityala, Ravishankar; Vidal, Carola; Jones, Robert

    Optical Coherence Tomography (OCT) has seen broad application in dentistry including early carious lesion detection and imaging defects in resin composite restorations. This study investigates expanding the clinical usefulness by investigating methods to use OCT for obtaining three-dimensional (3D) digital impressions, which can be integrated to CAD/CAM manufacturing of indirect restorations. 3D surface topography `before' and `after' a cavity preparation was acquired by an intraoral cross polarization swept source OCT (CP-OCT) system with a Micro-Electro-Mechanical System (MEMS) scanning mirror. Image registration and segmentation methods were used to digitally construct a replacement restoration that modeled the original surface morphology of a hydroxyapatite sample. After high resolution additive manufacturing (e.g. polymer 3D printing) of the replacement restoration, micro-CT imaging was performed to examine the marginal adaptation. This study establishes the protocol for further investigation of integrating OCT with CAD/CAM of indirect dental restorations.

  6. Nature versus nurture: functional assessment of restoration effects on wetland services using Nuclear Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Sundareshwar, P.V.; Richardson, C.J.; Gleason, R.A.; Pellechia, P.J.; Honomichl, S.

    2009-01-01

    Land-use change has altered the ability of wetlands to provide vital services such as nutrient retention. While compensatory practices attempt to restore degraded wetlands and their functions, it is difficult to evaluate the recovery of soil biogeochemical functions that are critical for restoration of ecosystem services. Using solution 31P Nuclear Magnetic Resonance Spectroscopy, we examined the chemical forms of phosphorus (P) in soils from wetlands located across a land-use gradient. We report that soil P diversity, a functional attribute, was lowest in farmland, and greatest in native wetlands. Soil P diversity increased with age of restoration, indicating restoration of biogeochemical function. The trend in soil P diversity was similar to documented trends in soil bacterial taxonomic composition but opposite that of soil bacterial diversity at our study sites. These findings provide insights into links between ecosystem structure and function and provide a tool for evaluating the success of ecosystem restoration efforts. Copyright 2009 by the American Geophysical Union.

  7. Comparison of shear bond strength of aesthetic restorative materials

    Directory of Open Access Journals (Sweden)

    B P Suryakumari Nujella

    2012-01-01

    Full Text Available Aim : The present study was conducted to determine and compare the shear bond strengths of Conventional glass ionomer; Resin-modified glass ionomer; Polyacid-modified composite and Composite Resin, and to assess and determine the mode of failure (adhesive, cohesive, mixed. Materials and Methods : Occlusal dentin of 40 extracted human teeth were randomly divided into four groups of ten teeth, each based on the restorative materials tested as follows: Group I: Conventional Glass Ionomer Cement (Control; Group II: Resin-modified Glass Ionomer Cement; Group III: Polyacid-modified Composite Resin; Group IV: Hybrid Composite Resin. The bonded materials were subjected to shear bond strength (SBS testing in a Instron Universal Testing Machine (UTM at a crosshead speed of 0.5 mm/min. The bond failure location was examined by the use of a stereomicroscope at 10× magnification. The mean SBS of Groups I-IV obtained was 3.81, 9.71, 11.96 and 18.16 MPa, respectively. Comparison of mean shear bond strengths of all groups was done by one way ANOVA test and comparison of means in between groups by the Student′s t test. Conclusion : It is concluded that the compomer restorative materials show higher shear bond strength than conventional glass-ionomer and resin-modified glass-ionomer, but less than composite resin.

  8. Technology needs for environmental restoration remedial action. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Watson, J.S.

    1992-11-01

    This report summarizes the current view of the most important technology needs for the US Department of Energy (DOE) facilities operated by Martin Marietta Energy Systems, Inc. These facilities are the Oak Ridge National Laboratory, the Oak Ridge K-25 Site, the Oak Ridge Y-12 Plant, the Paducah Gaseous Diffusion Plant, and the Portsmouth Gaseous Diffusion Plant. The sources of information used in this assessment were a survey of selected representatives of the Environmental Restoration (ER) programs at each facility, results from a questionnaire distributed by Geotech CWM, Inc., for DOE, and associated discussions with individuals from each facility. This is not a final assessment, but a brief look at an ongoing assessment; the needs will change as the plans for restoration change and, it is hoped, as some technical problems are solved through successful development programs.

  9. The clinical microscope and direct composite veneer

    DEFF Research Database (Denmark)

    Pascotto, Renata C; Benetti, Ana Raquel

    2010-01-01

    This paper presents the advantages and limitations related to the use of a clinical microscope in restorative dentistry, and it demonstrates the aid of magnification during preparation and restoration of a direct composite veneer. Good illumination and visibility is important to adequately viewing...

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

    Directory of Open Access Journals (Sweden)

    Hamid Kermanshah

    2016-01-01

    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 .

  11. Hydrological Classification, a Practical Tool for Mangrove Restoration.

    Science.gov (United States)

    Van Loon, Anne F; Te Brake, Bram; Van Huijgevoort, Marjolein H J; Dijksma, Roel

    2016-01-01

    Mangrove restoration projects, aimed at restoring important values of mangrove forests after degradation, often fail because hydrological conditions are disregarded. We present a simple, but robust methodology to determine hydrological suitability for mangrove species, which can guide restoration practice. In 15 natural and 8 disturbed sites (i.e. disused shrimp ponds) in three case study regions in south-east Asia, water levels were measured and vegetation species composition was determined. Using an existing hydrological classification for mangroves, sites were classified into hydrological classes, based on duration of inundation, and vegetation classes, based on occurrence of mangrove species. For the natural sites hydrological and vegetation classes were similar, showing clear distribution of mangrove species from wet to dry sites. Application of the classification to disturbed sites showed that in some locations hydrological conditions had been restored enough for mangrove vegetation to establish, in some locations hydrological conditions were suitable for various mangrove species but vegetation had not established naturally, and in some locations hydrological conditions were too wet for any mangrove species (natural or planted) to grow. We quantified the effect that removal of obstructions such as dams would have on the hydrology and found that failure of planting at one site could have been prevented. The hydrological classification needs relatively little data, i.e. water levels for a period of only one lunar tidal cycle without additional measurements, and uncertainties in the measurements and analysis are relatively small. For the study locations, the application of the hydrological classification gave important information about how to restore the hydrology to suitable conditions to improve natural regeneration or to plant mangrove species, which could not have been obtained by estimating elevation only. Based on this research a number of recommendations

  12. Hydrological Classification, a Practical Tool for Mangrove Restoration.

    Directory of Open Access Journals (Sweden)

    Anne F Van Loon

    Full Text Available Mangrove restoration projects, aimed at restoring important values of mangrove forests after degradation, often fail because hydrological conditions are disregarded. We present a simple, but robust methodology to determine hydrological suitability for mangrove species, which can guide restoration practice. In 15 natural and 8 disturbed sites (i.e. disused shrimp ponds in three case study regions in south-east Asia, water levels were measured and vegetation species composition was determined. Using an existing hydrological classification for mangroves, sites were classified into hydrological classes, based on duration of inundation, and vegetation classes, based on occurrence of mangrove species. For the natural sites hydrological and vegetation classes were similar, showing clear distribution of mangrove species from wet to dry sites. Application of the classification to disturbed sites showed that in some locations hydrological conditions had been restored enough for mangrove vegetation to establish, in some locations hydrological conditions were suitable for various mangrove species but vegetation had not established naturally, and in some locations hydrological conditions were too wet for any mangrove species (natural or planted to grow. We quantified the effect that removal of obstructions such as dams would have on the hydrology and found that failure of planting at one site could have been prevented. The hydrological classification needs relatively little data, i.e. water levels for a period of only one lunar tidal cycle without additional measurements, and uncertainties in the measurements and analysis are relatively small. For the study locations, the application of the hydrological classification gave important information about how to restore the hydrology to suitable conditions to improve natural regeneration or to plant mangrove species, which could not have been obtained by estimating elevation only. Based on this research a number

  13. Hydrological Classification, a Practical Tool for Mangrove Restoration

    Science.gov (United States)

    Van Loon, Anne F.; Te Brake, Bram; Van Huijgevoort, Marjolein H. J.; Dijksma, Roel

    2016-01-01

    Mangrove restoration projects, aimed at restoring important values of mangrove forests after degradation, often fail because hydrological conditions are disregarded. We present a simple, but robust methodology to determine hydrological suitability for mangrove species, which can guide restoration practice. In 15 natural and 8 disturbed sites (i.e. disused shrimp ponds) in three case study regions in south-east Asia, water levels were measured and vegetation species composition was determined. Using an existing hydrological classification for mangroves, sites were classified into hydrological classes, based on duration of inundation, and vegetation classes, based on occurrence of mangrove species. For the natural sites hydrological and vegetation classes were similar, showing clear distribution of mangrove species from wet to dry sites. Application of the classification to disturbed sites showed that in some locations hydrological conditions had been restored enough for mangrove vegetation to establish, in some locations hydrological conditions were suitable for various mangrove species but vegetation had not established naturally, and in some locations hydrological conditions were too wet for any mangrove species (natural or planted) to grow. We quantified the effect that removal of obstructions such as dams would have on the hydrology and found that failure of planting at one site could have been prevented. The hydrological classification needs relatively little data, i.e. water levels for a period of only one lunar tidal cycle without additional measurements, and uncertainties in the measurements and analysis are relatively small. For the study locations, the application of the hydrological classification gave important information about how to restore the hydrology to suitable conditions to improve natural regeneration or to plant mangrove species, which could not have been obtained by estimating elevation only. Based on this research a number of recommendations

  14. Ceramic restoration repair: report of two cases

    Directory of Open Access Journals (Sweden)

    Luís Henrique Araújo Raposo

    2009-04-01

    Full Text Available The esthetic and functional rehabilitation of patients with multiple missing teeth can be performed with several techniques and materials. Ceramic restorations provide reliable masticatory function and good esthetics. However, fracture can occur in some cases due to their brittle behavior. In some cases, the replacement of an extensive prosthesis is a problem due to the high treatment cost. In this paper, two cases are presented, in which fractures occurred in extensive metal-ceramic fixed partial dentures, and their replacement was not possible. Ceramic repair was chosen and the sequences of treatment with and without presence of the ceramic fragment are also discussed. The cases illustrate that, in some situations, fractured metal-ceramic partial dentures can be successfully repaired when prosthetic replacement is not a choice. Prosthodontists must use alternatives that allow a reliable repair to extensive metal-ceramic fixed partial dentures. Surface preparation of the ceramic with hydrofluoric acid in conjunction with a silane coupling agent is essential for a predictable bonding of composite resin. The repair performed with composite resin is an esthetic and functional alternative when extensive fixed partial dentures cannot be replaced.

  15. Wetland restoration: a survey of options for restoring peatlands

    International Nuclear Information System (INIS)

    In spite of increased attention to wetland conservation following the Ramsar Convention on Wetlands of International Importance, the peat-harvesting industry in many countries is still interested in the further exploitation of peatlands. In some of the most industrialised countries, all natural peatlands have already been lost. In others, only small areas of native peatland remain. Among other possible uses for cut-over peatlands, peatland restoration is one: there is an urgent need for the development of measures for regenerating peat-accumulation processes. The redevelopment of a fen or bog peat landscape is a long-term process, which will probably take centuries. The restoration of any peatland may therefore be considered successful if the outcome is the development and growth of plant communities able to produce peat. The renewal of the hydrological regime of such areas is a major factor which determines the re-colonisation of cut-over peat fields by peat-forming plants. The aim of this paper is to give a brief survey of wetlands, and especially of peatland restoration options, for use in terminated peat-cuttings. It aims to show how peatland management may be made sustainable by means of existing and tried methods and principles, with the goal of returning cut-over peat fields to their former peat-accumulating state. A glossary of peat and peatland terminology is included 105 refs, 5 figs

  16. The plant pathology of native plant restoration

    Science.gov (United States)

    Restoration of ecologically degraded sites will benefit from the convergence of knowledge drawn from such disparate and often compartmentalized (and heretofore not widely considered) areas of research as soil microbial ecology, plant pathology and agronomy. Restoration following biological control w...

  17. Economic barriers and incentives for biodiversity restoration

    International Nuclear Information System (INIS)

    Costs related with restoration efforts, as well as the economic incentives, are fundamental issues that have not been fully considered from a formal standpoint. Through the analysis of restoration trials in collaboration with an indigenous community in western Mexico, we analyzed economic issues related with the restoration trials themselves, and with the economic context that gives incentives for ecological restoration. We reach to the conclusion that the cost-benefit relationship of the restoration process by itself can be straightforward calculated in some cases, calculating economic benefits accrued from the diversity restored to ecosystem is more difficult. In terms of the incentives for biodiversity restoration, we concluded that in many cases, economic variables out of the control of those involved in restoration are determinant.

  18. Poplar Island Environmental Restoration Project Nekton Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Poplar Island Environmental Restoration Project (PIERP) is a large scale 1,800 acres restoration project located in mid Chesapeake Bay. Fishery collections are...

  19. Dental Composites and Amalgam and Physical Development in Children

    OpenAIRE

    Maserejian, N.N.; Hauser, R.; Tavares, M.; Trachtenberg, F. L.; Shrader, P.; McKinlay, S.

    2012-01-01

    Resin-based composite dental restoration materials may release bisphenol-A, an endocrine-disrupting chemical. Using secondary analysis of a randomized clinical safety trial of amalgam vs. composites, we tested the hypothesis that dental restoration materials affect children’s growth. Children (N = 218 boys, N = 256 girls) aged 6 to 10 yrs at baseline with ≥ 2 decayed posterior teeth were randomized to amalgam or composites (bisphenol-A-diglycidyl-dimethacrylate composite for permanent teeth, ...

  20. Monitoring the Diversity of Hunting Ants (Hymenoptera: Formicidae) on a Fragmented and Restored Andean Landscape.

    Science.gov (United States)

    Herrera-Rangel, J; Jiménez-Carmona, E; Armbrecht, I

    2015-10-01

    Hunting ants are predators of organisms belonging to different trophic levels. Their presence, abundance, and diversity may reflect the diversity of other ants and contribute to evaluate habitat conditions. Between 2003 and 2005 the restoration of seven corridors in an Andean rural landscape of Colombia was performed. The restoration took place in lands that were formerly either forestry plantations or pasturelands. To evaluate restoration progress, hunting ants were intensely sampled for 7 yr, using sifted leaf litter and mini-Winkler, and pitfall traps in 21 plots classified into five vegetation types: forests, riparian forests, two types of restored corridors, and pasturelands. The ant communities were faithful to their habitat over time, and the main differences in ant composition, abundance, and richness were due to differences among land use types. The forests and riparian forests support 45% of the species in the landscape while the restored corridors contain between 8.3-25%. The change from forest to pasturelands represents a loss of 80% of the species. Ant composition in restored corridors was significantly different than in forests but restored corridors of soil of forestry plantations retained 16.7% more species than restored corridors from pasturelands. Ubiquitous hunting ants, Hypoponera opacior (Forel) and Gnamptogenys ca andina were usually associated with pastures and dominate restored corridors. Other cryptic, small, and specialized hunting ants are not present in the restored corridors. Results suggest that the history of land use is important for the biodiversity of hunting ants but also that corridors have not yet effectively contributed toward conservation goals. PMID:26314006

  1. Calcium aluminate cement as dental restorative : Mechanical properties and clinical durability

    OpenAIRE

    Sunnegårdh-Grönberg, Karin

    2004-01-01

    In 1995, the Swedish government recommended the discontinuation of amalgam as restorative in paediatric dentistry. Because the mercury content in amalgam constitutes an environmental hazard, its use has declined. The use of resin composites is increasing, but the polymerisation shrinkage of the material is still undesirably high, and the handling of uncured resin can cause contact dermatitis. A new restorative material has recently been developed in Sweden as an alternative to amalgam and res...

  2. Effects of high temperatures on different dental restorative systems: Experimental study to aid identification processes

    Directory of Open Access Journals (Sweden)

    Sandra Moreno

    2009-01-01

    Our observations showed that the class I restorations made of amalgam on glass ionomer bases as far as the class I restorations made of ZnO modified temporary filling material can be identified till 1200°C because they maintain their shape despite the disintegration of the crowns, whilst the class I composite/adhesive system and the underplayed glass ionomer bases remained in place in an altered shape.

  3. UV completion without symmetry restoration

    CERN Document Server

    Endlich, Solomon; Penco, Riccardo

    2013-01-01

    We show that it is not possible to UV-complete certain low-energy effective theories with spontaneously broken space-time symmetries by embedding them into linear sigma models, that is, by adding "radial" modes and restoring the broken symmetries. When such a UV completion is not possible, one can still raise the cutoff up to arbitrarily higher energies by adding fields that transform non-linearly under the broken symmetries, that is, new Goldstone bosons. However, this (partial) UV completion does not necessarily restore any of the broken symmetries. We illustrate this point by considering a concrete example in which a combination of space-time and internal symmetries is broken down to a diagonal subgroup. Along the way, we clarify a recently proposed interpretation of inverse Higgs constraints as gauge-fixing conditions.

  4. Resilience and Restoration of Lakes

    Directory of Open Access Journals (Sweden)

    Kathryn L. Cottingham

    1997-06-01

    Full Text Available Lake water quality and ecosystem services are normally maintained by several feedbacks. Among these are nutrient retention and humic production by wetlands, nutrient retention and woody habitat production by riparian forests, food web structures that cha nnel phosphorus to consumers rather than phytoplankton, and biogeochemical mechanisms that inhibit phosphorus recycling from sediments. In degraded lakes, these resilience mechanisms are replaced by new ones that connect lakes to larger, regional economi c and social systems. New controls that maintain degraded lakes include runoff from agricultural and urban areas, absence of wetlands and riparian forests, and changes in lake food webs and biogeochemistry that channel phosphorus to blooms of nuisance al gae. Economic analyses show that degraded lakes are significantly less valuable than normal lakes. Because of this difference in value, the economic benefits of restoring lakes could be used to create incentives for lake restoration.

  5. Image restoration in digital photography

    OpenAIRE

    Lam, EY

    2003-01-01

    This paper introduces some novel image restoration algorithms for digital photography, which has one of the fastest growing consumer electronics markets in recent years. Many attempts have been made to improve the quality of the digital pictures in comparison with photography taken on films. A lot of these methods have their roots in discrete signal and image processing developed over the last two decades, but the ever-increasing computational power of personal computers has made possible new...

  6. Image restoration and processing methods

    International Nuclear Information System (INIS)

    This review will stress the importance of using image restoration techniques that deal with incomplete, inconsistent, and noisy data and do not introduce spurious features into the processed image. No single image is equally suitable for both the resolution of detail and the accurate measurement of intensities. A good general purpose technique is the maximum entropy method and the basis and use of this will be explained. (orig.)

  7. RESTORING VISION USING HUMAN OPSINS

    OpenAIRE

    Cehajic-Kapetanovic, Jasmina

    2016-01-01

    Restoring vision using human opsinsJasmina Cehajic-Kapetanovic; The University of Manchester, Doctor of Philosophy, 2015Inherited retinal degenerations (IRDs) are progressive degenerative conditions that affect around 1 in 2500 people worldwide and lead to severe visual impairment due to irreversible loss of photoreceptors. These conditions are currently untreatable. However, inner retinal neurons, including bipolar and ganglion cells, can survive representing promising targets for emerging o...

  8. Phonemic restoration in developmental dyslexia

    OpenAIRE

    Del Tufo, Stephanie N.; Myers, Emily B.

    2014-01-01

    The comprehension of fluent speech in one's native language requires that listeners integrate the detailed acoustic-phonetic information available in the sound signal with linguistic knowledge. This interplay is especially apparent in the phoneme restoration effect, a phenomenon in which a missing phoneme is “restored” via the influence of top-down information from the lexicon and through bottom-up acoustic processing. Developmental dyslexia is a disorder characterized by an inability to read...

  9. Phonemic restoration in developmental dyslexia

    OpenAIRE

    Del Tufo, Stephanie N.; Myers, Emily B.

    2014-01-01

    The comprehension of fluent speech in one’s native language requires that listeners integrate the detailed acoustic-phonetic information available in the sound signal with linguistic knowledge. This interplay is especially apparent in the phoneme restoration effect, a phenomenon in which a missing phoneme is ‘restored’ via the influence of top-down information from the lexicon and through bottom-up acoustic processing. Developmental dyslexia is a disorder characterized by an inability to read...

  10. Zirconia-reinforced dental restorations

    OpenAIRE

    Feilzer, A.J.; Kleverlaan, C. J.; Chen, C.

    2013-01-01

    The series of studies conducted in this thesis showed that there are several ways to enhance the performance of fixed restorations regarding the application of zirconia. One possible way is to change the sintering procedure of zirconia, so that the physical properties of zirconia such BFS, density or grain size can also be changed. In the other hand, with the experimental zirconia-silica coating technique, the bond strength of zirconia frameworks can be improved, in order to reduce the clinic...

  11. Methodology for ranking restoration options

    International Nuclear Information System (INIS)

    The work described in this report has been performed as a part of the RESTRAT Project FI4P-CT95-0021a (PL 950128) co-funded by the Nuclear Fission Safety Programme of the European Commission. The RESTRAT project has the overall objective of developing generic methodologies for ranking restoration techniques as a function of contamination and site characteristics. The project includes analyses of existing remediation methodologies and contaminated sites, and is structured in the following steps: characterisation of relevant contaminated sites; identification and characterisation of relevant restoration techniques; assessment of the radiological impact; development and application of a selection methodology for restoration options; formulation of generic conclusions and development of a manual. The project is intended to apply to situations in which sites with nuclear installations have been contaminated with radioactive materials as a result of the operation of these installations. The areas considered for remedial measures include contaminated land areas, rivers and sediments in rivers, lakes, and sea areas. Five contaminated European sites have been studied. Various remedial measures have been envisaged with respect to the optimisation of the protection of the populations being exposed to the radionuclides at the sites. Cost-benefit analysis and multi-attribute utility analysis have been applied for optimisation. Health, economic and social attributes have been included and weighting factors for the different attributes have been determined by the use of scaling constants. (au)

  12. Environmental Restoration 1997 annual report

    International Nuclear Information System (INIS)

    During 1997, the Environmental Restoration Program at the Savannah River Site achieved all of the ''Breakthrough Goals'' that were established with the regulatory agencies in 1995 to advance their cleanup efforts. Effective focus on field remediation was demonstrated by the allocation of 75% of program funding to remediation activities. The Remediation Phase is complete or has begun on sixty-nine waste sites that represent approximately 80% of the known environmental and health risk. The average time required for the assessment phase of active projects was reduced by 50%, from 49 to less than 24 months, which allows cleanup actions to start twice as fast as before. Breakthrough performance has tangible results. During 1997, all of the funding allocation was used effectively to accomplish environmental restoration scope worth over $123 million. That represents a validated cost efficiency of over 20% for the third straight year. Over half of the 500 contaminated acres at SRS have been cleaned up or are currently in the remediation phase. Almost 3 billion gallons of groundwater have been restored by removing over half a million pounds of organic solvents

  13. Effect of different restorative procedures on the fracture resistance of teeth submitted to internal bleaching

    Directory of Open Access Journals (Sweden)

    Andiara Ribeiro Roberto

    2012-02-01

    Full Text Available The aim of this study was to evaluate the influence of different restorative procedures on the fracture resistance of endodontically treated teeth submitted to intracoronal bleaching. Fifty upper central incisors were distributed into 5 groups: GI - healthy teeth; GII - endodontically treated teeth sealed with Coltosol; GIII - endodontically treated teeth bleached and sealed with Coltosol; GIV - endodontically treated teeth bleached and restored with composite resin; and GV - endodontically treated teeth bleached and restored with a fiberglass post and composite resin. In the bleached specimens, a cervical seal was made prior to bleaching with 38% hydrogen peroxide. The gel was applied on the buccal surface and in the pulp chamber, and was then light-activated for 45 s. This procedure was repeated three times per session for four sessions, and each group was submitted to the restorative procedures described above. The specimens were submitted to fracture resistance testing in a universal testing machine. There were statistically significant differences among the groups (p 0.05. The restorative procedures using composite resin were found to successfully restore the fracture resistance of endodontically treated and bleached teeth.

  14. Soil Seed Bank and Plant Community Development in Passive Restoration of Degraded Sandy Grasslands

    Directory of Open Access Journals (Sweden)

    Renhui Miao

    2016-06-01

    Full Text Available To evaluate the efficacy of passive restoration on soil seed bank and vegetation recovery, we measured the species composition and density of the soil seed bank, as well as the species composition, density, coverage, and height of the extant vegetation in sites passively restored for 0, 4, 7, and 12 years (S0, S4, S7, and S12 in a degraded grassland in desert land. Compared with S0, three more species in the soil seed bank at depths of 0–30 cm and one more plant species in the community was detected in S12. Seed density within the topsoil (0–5 cm was five times higher in S12 than that in S0. Plant densities in S7 and S12 were triple and quadruple than that in S0. Plant coverage was increased by 1.5 times (S4, double (S7, and triple (S12 compared with S0. Sørensen’s index of similarity in species composition between the soil seed bank and the plant community were high (0.43–0.63, but it was lower in short-term restoration sites (S4 and S7 than that in no and long-term restoration sites (S0 and S12. The soil seed bank recovered more slowly than the plant community under passive restoration. Passive restoration is a useful method to recover the soil seed bank and vegetation in degraded grasslands.

  15. Communities of terrestrial nematodes after different approaches to heathland restoration

    Science.gov (United States)

    Radochova, Petra; Frouz, Jan

    2016-04-01

    Since the 20th century, the distribution of European heathlands rapidly decreased due to agricultural intensification, heavy use of artificial fertilizers or acidification (Aerts & Heil, 1993). Therefore, various attempts of heathland restoration are under way in these days. Analysis of nematode community composition can be one of the tools suitable for succession evaluation (Ferris et al., 2001). In 2011, 2013 and 2014, soil samples were collected from heathland restoration experiment (launched in 2011) where different restoration methods were applied in a 3 × 3 factorial experiment; existing heathlands were also sampled to identify the target community both in dry and wet heathland. A total of 60 samples of extracted nematodes were analysed for absolute abundance, trophic groups, and genera dominance. Various indices were calculated to describe the nematode community. We were able to prove faster development of wet heathlands towards the target community. However, because of large data variability, there was no significant difference between treatments. Development of wet and dry heathlands differed also in increased proportion of omniphagous nematodes in 2013 and predators in 2014 in dry heathlands. After three years of heathland restoration, nematode community has not yet reached parameters of the target community. References Aerts, R., Heil, G. W., 1993. Heathlands: patterns and processes in a changing environment, 1st ed, Geobotany: 20. Springer Netherlands, Dordrecht, p. 229. Ferris, H., Bongers, T., De Goede, R. G. M., 2001. A framework for soil food web diagnostics: Extension of the nematode faunal analysis oncept. Appl. Soil Ecol. 18, 13-29.

  16. Microbial diversity in restored wetlands of San Francisco Bay

    Energy Technology Data Exchange (ETDEWEB)

    Theroux, Susanna [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Hartman, Wyatt [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; He, Shaomei [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Univ. of Wisconsin, Madison, WI (United States); Tringe, Susannah [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.

    2013-12-09

    Wetland ecosystems may serve as either a source or a sink for atmospheric carbon and greenhouse gases. This delicate carbon balance is influenced by the activity of belowground microbial communities that return carbon dioxide and methane to the atmosphere. Wetland restoration efforts in the San Francisco Bay-Delta region may help to reverse land subsidence and possibly increase carbon storage in soils. However, the effects of wetland restoration on microbial communities, which mediate soil metabolic activity and carbon cycling, are poorly studied. In an effort to better understand the underlying factors which shape the balance of carbon flux in wetland soils, we targeted the microbial communities in a suite of restored and historic wetlands in the San Francisco Bay-Delta region. Using DNA and RNA sequencing, coupled with greenhouse gas monitoring, we profiled the diversity and metabolic potential of the wetland soil microbial communities along biogeochemical and wetland age gradients. Our results show relationships among geochemical gradients, availability of electron acceptors, and microbial community composition. Our study provides the first genomic glimpse into microbial populations in natural and restored wetlands of the San Francisco Bay-Delta region and provides a valuable benchmark for future studies.

  17. 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

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

    Directory of Open Access Journals (Sweden)

    Chetan A Pol

    2015-01-01

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

  19. Factors affecting re-vegetation dynamics of experimentally restored extracted peatland in Estonia.

    Science.gov (United States)

    Karofeld, Edgar; Müür, Mari; Vellak, Kai

    2016-07-01

    Increasing human activity continues to threaten peatlands, and as the area of natural mires declines, our obligation is to restore their ecosystem functions. Several restoration strategies have been developed for restoration of extracted peatlands, including "The moss layer transfer method", which was initiated on the Tässi extracted peatland in central Estonia in May 2012. Three-year study shows that despite the fluctuating water table, rainfall events can compensate for the insufficient moisture for mosses. Total plant cover on the restoration area attained 70 %, of which ~60 % is comprised of target species-Sphagnum mosses. From restoration treatments, spreading of plant fragments had a significant positive effect on the cover of bryophyte and vascular plants. Higher water table combined with higher plant fragments spreading density and stripping of oxidised peat layer affected positively the cover of targeted Sphagnum species. The species composition in the restoration area became similar to that in the donor site in a natural bog. Based on results, it was concluded that the method approved for restoration in North America gives good results also in the restoration of extracted peatland towards re-establishment of bog vegetation under northern European conditions. PMID:26490883

  20. Radio-opaque dental compositions

    International Nuclear Information System (INIS)

    Thorium oxide or tantalum oxide, or combinations thereof are used as the x-ray material for radio-opaque filler compositions having particular applicability in dental restorative compositions. The filler compositions contain from about 3% by weight to about 10% by weight, based on the total filler composition, of the x-ray absorbing materials and the remainder being conventional particulate glass or silica, quarts or ceramic filler material. The radio opaque filler compositions are insoluble and non-leachable in alkaline, acidic or neutral aqueous environments, are essentially non-toxic, are either essentially colorless or translucent, and are compatible with acrylic monomers and other polymerizable binder systems

  1. Gradual surface degradation of restorative materials by acidic agents.

    Science.gov (United States)

    Hengtrakool, Chanothai; Kukiattrakoon, Boonlert; Kedjarune-Leggat, Ureporn

    2011-01-01

    The aim of this study was to investigate the effect of acidic agents on surface roughness and characteristics of four restorative materials. Fifty-two discs were created from each restorative material: metal-reinforced glass ionomer cement (Ketac-S), resin-modified glass ionomer cement (Fuji II LC), resin composite (Filtek Z250), and amalgam (Valiant-PhD); each disc was 12 mm in diameter and 2.5 mm thick. The specimens were divided into four subgroups (n=13) and immersed for 168 hours in four storage media: deionized water (control); citrate buffer solution; green mango juice; and pineapple juice. Surface roughness measurements were performed with a profilometer, both before and after storage media immersion. Surface characteristics were examined using scanning electron microscopy (SEM). Statistical significance among each group was analyzed using two-way repeated ANOVA and Tukey's tests. Ketac-S demonstrated the highest roughness changes after immersion in acidic agents (pValiant-PhD and Filtek Z250 illustrated some minor changes over 168 hours. The mango juice produced the greatest degradation effect of all materials tested (p<0.05). SEM photographs demonstrated gradual surface changes of all materials tested after immersions. Of the materials evaluated, amalgam and resin composite may be the most suitable for restorations for patients with tooth surface loss. PMID:21903509

  2. The science and practice of river restoration

    Science.gov (United States)

    Wohl, Ellen; Lane, Stuart N.; Wilcox, Andrew C.

    2015-08-01

    River restoration is one of the most prominent areas of applied water-resources science. From an initial focus on enhancing fish habitat or river appearance, primarily through structural modification of channel form, restoration has expanded to incorporate a wide variety of management activities designed to enhance river process and form. Restoration is conducted on headwater streams, large lowland rivers, and entire river networks in urban, agricultural, and less intensively human-altered environments. We critically examine how contemporary practitioners approach river restoration and challenges for implementing restoration, which include clearly identified objectives, holistic understanding of rivers as ecosystems, and the role of restoration as a social process. We also examine challenges for scientific understanding in river restoration. These include: how physical complexity supports biogeochemical function, stream metabolism, and stream ecosystem productivity; characterizing response curves of different river components; understanding sediment dynamics; and increasing appreciation of the importance of incorporating climate change considerations and resiliency into restoration planning. Finally, we examine changes in river restoration within the past decade, such as increasing use of stream mitigation banking; development of new tools and technologies; different types of process-based restoration; growing recognition of the importance of biological-physical feedbacks in rivers; increasing expectations of water quality improvements from restoration; and more effective communication between practitioners and river scientists.

  3. Using restoration ecology for the restoration of valuable habitats

    Czech Academy of Sciences Publication Activity Database

    Prach, Karel

    České Budějovice : Faculty of Science, University of South Bohemia in České Budějovice, 2011 - (Řehounková, K.; Řehounek, J.; Prach, K.), s. 9-11 ISBN 978-80-7394-322-6 R&D Projects: GA ČR(CZ) GAP505/11/0256 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : restoration ecology * diversity * mining Subject RIV: EH - Ecology, Behaviour

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

    Directory of Open Access Journals (Sweden)

    Juliane Mendes de ARAÚJO

    2006-08-01

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

  5. Biocompatibility of a restorative resin-modified glass ionomer cement applied in very deep cavities prepared in human teeth.

    Science.gov (United States)

    Soares, Diana Gabriela; Basso, Fernanda Gonçalves; Scheffel, Débora Lopes Sales; Giro, Elisa Maria Aparecida; de Souza Costa, Carlos Alberto; Hebling, Josimeri

    2016-01-01

    This study evaluated whether a restorative resin-modified glass ionomer cement, Vitremer (VM), would be biocompatible with pulp tissue when used as a liner in very deep cavities prepared in young human permanent teeth. Two dental cements in current use as liner materials, Vitrebond (VB) and Dycal (DY), were compared to VM. Class V cavities were prepared in 36 sound premolars that were scheduled for extraction, and the cavity floor was lined with the restorative cement (VM) or a liner/base control cement (VB or DY). For VM specimens, the cavity floor was pretreated with a primer (polyacrylic acid plus 2-hydroxyethyl methacrylate). Teeth were extracted after 7 or 30 days and processed for microscopic evaluation. In the VM group, inward diffusion of dental material components through dentinal tubules, associated with disruption of the odontoblastic layer, moderate to intense inflammatory response, and resorption of inner dentin, was observed in 2 teeth at 7 days. These histologic features were observed in 1 tooth at 30 days. In the VB group, mild inflammatory reactions and tissue disorganization observed at 7 days were resolved at 30 days. No pulpal damage occurred in the DY specimens. Of the materials tested, only Vitremer was not considered biocompatible, because it caused persistent pulpal damage when applied in very deep cavities (remaining dentin thickness less than 0.3 mm). PMID:27367631

  6. Does Habitat Restoration Increase Coexistence of Native Stream Fishes with Introduced Brown Trout: A Case Study on the Middle Provo River, Utah, USA

    Directory of Open Access Journals (Sweden)

    Mark C. Belk

    2016-03-01

    Full Text Available Restoration of altered or degraded habitats is often a key component in the conservation plan of native aquatic species, but introduced species may influence the response of the native community to restoration. Recent habitat restoration of the middle section of the Provo River in central Utah, USA, provided an opportunity to evaluate the effect of habitat restoration on the native fish community in a system with an introduced, dominant predator—brown trout (Salmo trutta. To determine the change in distribution of fish species and community composition, we surveyed 200 m of each of the four study reaches both before restoration (1998 and after restoration (2007 and 2009. Juveniles and adults of six native species increased in distribution after restoration. The variation in fish community structure among reaches was lower post-restoration than pre-restoration. Overall, restoration of complex habitat in the middle Provo River led to increased pattern of coexistence between native fishes and introduced brown trout, but restoration activities did not improve the status of the river’s two rarest native fish species. Habitat restoration may only be completely successful in terms of restoring native communities when the abundance of invasive species can be kept at low levels.

  7. Influence of coronal restorations on the fracture resistance of root canal-treated premolar and molar teeth: a retrospective study.

    Science.gov (United States)

    Dammaschke, Till; Nykiel, Kathrin; Sagheri, Darius; Schäfer, Edgar

    2013-08-01

    To evaluate the influence of coronal restorations on the fracture resistance of endodontically treated teeth, 676 root canal-filled and restored posterior teeth were evaluated after a mean period of 9.7 (± 2.8; minimum: 5) years. A total of 86.2% of the endodontically treated and restored teeth survived the mean observation period of 9.7 years without fracture. The overall survival period was 13.6 (± 0.2) years. All teeth with gold partial crowns survived without fractures (n = 24). Teeth with crowns and adhesively sealed access cavities showed a mean survival period of 15.3 (± 0.4) years, with crown and bridge restorations 14.0 (± 0.3), with individual metal posts 13.9 (± 0.2), with composite fillings 13.4 (± 0.5), with prefabricated metal posts 12.7 (± 0.6), with amalgam fillings 11.8 (± 0.6) and with glass ionomer cements (GIC) 6.6 (± 0.5) years. Teeth with one or two surfaces restored by amalgam, composite or GIC showed a significantly lower fracture rate than teeth with three and more restored surfaces (P < 0.05). The mean fracture rate of teeth restored with GIC was significantly higher when compared with all other groups (P < 0.001). In general, endodontically treated teeth restored with prosthetic restorations demonstrated a significantly lower mean fracture rate than teeth restored with fillings. Cavities with up to three surfaces may well be successfully restored adhesively with composite filling material. PMID:23890259

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  9. Provisional materials: key components of interim fixed restorations.

    Science.gov (United States)

    Perry, Ronald D; Magnuson, Britta

    2012-01-01

    Clinicians have many choices of provisional materials from which to choose when fabricating interim fixed restorations. While traditional materials are still in use today, temporary materials are continuously being updated and improved upon. In addition to the functional necessities required of the provisional material, it must also provide esthetic value for the patient. This article provides an overview of provisional materials, including newer bis-acryls that have helped eliminate some of the challenges associated with traditional acrylic materials. Composite resin preformed crowns for single-unit provisional applications are also discussed, along with CAD/CAM-fabricated materials. Regardless of the material selected, a provisional restoration must maintain and protect the underlying tooth structure from ill effects. PMID:22432178

  10. Factors influencing bonding fixed restorations

    Directory of Open Access Journals (Sweden)

    Medić Vesna

    2008-01-01

    Full Text Available INTRODUCTION Crown displacement often occurs because the features of tooth preparations do not counteract the forces directed against restorations. OBJECTIVE The purpose of this study was to evaluate the effect of preparation designs on retention and resistance of fixed restorations. METHOD The study was performed on 64 differently sized stainless steel dies. Also, caps which were used for evaluated retention were made of stainless steel for each die. After cementing the caps on experimental dies, measuring of necessary tensile forces to separate cemented caps from dies was done. Caps, which were made of a silver-palladium alloy with a slope of 60° to the longitudinal axis formed on the occlusal surface, were used for evaluating resistance. A sudden drop in load pressure recorded by the test machine indicated failure for that cap. RESULTS A significant difference was found between the tensile force required to remove the caps from the dies with different length (p<0.05 and different taper (p<0.01. The greatest retentive strengths (2579.2 N and 2989.8 N were noticed in experimental dies with the greatest length and smallest taper. No statistically significant (p>0.05 differences were found between tensile loads for caps cemented on dies with different diameter. Although there was an apparent slight increase in resistance values for caps on dies with smaller tapers, the increase in resistance for those preparation designs was not statistically significant. There was a significant difference among the resistance values for caps on dies with different length (p<0.01 and diameter (p<0.05. CONCLUSION In the light of the results obtained, it could be reasonably concluded that retention and resistance of the restoration is in inverse proportion to convergence angle of the prepared teeth. But, at a constant convergence angle, retention and resistance increase with rising length and diameter.

  11. PIXE and ERDA analysis of composites for restorative dentistry

    International Nuclear Information System (INIS)

    We studied 14 commercial and 3 Romanian biomaterials using 3 MeV proton particle-induced X-ray emission (PIXE) and copper-beam elastic detection analysis (ERDA). PIXE detected up to 27 elements with Z ≥ 14 (Si, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Sr, Y, Zr, Nb, Ru, Ag, Cd, Ba, Nd, Ho, Yb, Hf, Au, Pb, many of them at trace levels), while ERDA evidenced up to 13 elements with Z ≤ 20 (H, B, C, N, O, F, Na, Al, Si, P, Cl, K, Ca). Relative concentrations were evaluated. (authors)

  12. Light induced polymerization of resin composite restorative materials

    OpenAIRE

    Blažić Larisa; Marković Dubravka; Đurić Milanko

    2004-01-01

    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. Polymerizatio...

  13. Environmental restoration using horizontal wells

    International Nuclear Information System (INIS)

    This paper reports that under sponsorship from the U.S. Department of Energy, technical personnel from the Savannah River Laboratory and other DOE laboratories, universities and private industry have completed a full scale demonstration of environmental remediation using horizontal wells. The test successfully removed approximately 7250 kg of contaminants. A large amount of characterization and monitoring data was collected to aid in interpretation of the test and to provide the information needed for future environmental restorations that employ directionally drilled wells as extraction or delivery systems

  14. Call to restore Mesopotamian marshlands

    Science.gov (United States)

    Showstack, Randy

    When the current military conflict in Iraq has concluded, a rehabilitation of that country should include a full assessment and action plan for restoring the marshlands of Mesopotamia, the United Nations Environment Programme said on 22 March.The marshlands, also known as the Fertile Crescent, could disappear within three to five years, according to UNEP.UNEP Executive Director Klaus Toepfer said the loss of the marshlands “is an environmental catastrophe for this region and underscores the huge pressures facing wetlands and freshwater ecosystems across the world.”

  15. Gauss law and symmetry restoration

    International Nuclear Information System (INIS)

    The authors study the restoration of global symmetries of lattice QCD at finite temperature and chemical potential for an arbitrary number of colors Nc and flavors Nf. The Hamiltonian in the Ao gauge has to be supplemented by the Gauss law constraint, that thermal excitations must satisfy. The authors study the problem in the strong-coupling limit and in a Bogoliubov approximation. The free energy to be minimized must be defined by traces over states restricted in the color singlet Hilbert space at each lattice site

  16. Current status of zirconia restoration.

    Science.gov (United States)

    Miyazaki, Takashi; Nakamura, Takashi; Matsumura, Hideo; Ban, Seiji; Kobayashi, Taira

    2013-10-01

    During the past decade, zirconia-based ceramics have been successfully introduced into the clinic to fabricate fixed dental prostheses (FDPs), along with a dental computer-aided/computer-aided manufacturing (CAD/CAM) system. In this article (1) development of dental ceramics, (2) the current status of dental CAD/CAM systems, (3) CAD/CAM and zirconia restoration, (4) bond between zirconia and veneering ceramics, (5) bond of zirconia with resin-based luting agents, (6) surface finish of zirconia restoration and antagonist enamel wear, and (7) clinical evaluation of zirconia restoration are reviewed. Yttria partially stabilized tetragonal zirconia polycrystalline (Y-TZP) showed better mechanical properties and superior resistance to fracture than other conventional dental ceramics. Furthermore, ceria-stabilized tetragonal zirconia polycrystalline and alumina nanocomposites (Ce-TZP/A) had the highest fracture toughness and had resistance to low-temperature aging degradation. Both zirconia-based ceramics have been clinically available as an alternative to the metal framework for fixed dental prostheses (FDPs). Marginal adaptation of zirconia-based FDPs is acceptable for clinical application. The most frequent clinical complication with zirconia-based FDPs was chipping of the veneering porcelain that was affected by many factors. The mechanism for the bonding between zirconia and veneering ceramics remains unknown. There was no clear evidence of chemical bonding and the bond strength between zirconia and porcelain was lower than that between metal and porcelain. There were two alternatives proposed that might avoid chipping of veneering porcelains. One was hybrid-structured FDPs comprising CAD/CAM-fabricated porcelain parts adhering to a CAD/CAM fabricated zirconia framework. Another option was full-contour zirconia FDPs using high translucent zirconia. Combined application of silica coating and/or silane coupler, and 10-methacryloyloxydecyl dihydrogen phosphate is

  17. Complications in hair restoration surgery.

    Science.gov (United States)

    Perez-Meza, David; Niedbalski, Robert

    2009-02-01

    Hair loss affects more than 1.2 billion people worldwide. As the technology and artistry of hair restoration surgery has improved including natural results, so too has the popularity of this procedure. As with any other surgical procedure, complications may occur and this presents a major challenge for the surgeon and the patient. This article provides an overview of the complications most likely to occur during the pre, intra, and postoperative periods with modern hair transplant surgery (single follicular unit or multifollicular unit) including scalp surgery, and discusses their treatment and most importantly their prevention. PMID:19185800

  18. Endangered species management and ecosystem restoration: Finding the common ground

    Science.gov (United States)

    Casazza, Michael L.; Overton, Cory T.; Bui, Thuy-Vy D.; Hull, Joshua M.; Albertson, Joy D.; Bloom, Valary K.; Bobzien, Steven; McBroom, Jennifer; Latta, Marilyn; Olofson, Peggy; Rohmer, Tobias M.; Schwarzbach, Steven E.; Strong, Donald R.; Grijalva, Erik; Wood, Julian K.; Skalos, Shannon; Takekawa, John

    2016-01-01

    Management actions to protect endangered species and conserve ecosystem function may not always be in precise alignment. Efforts to recover the California Ridgway’s Rail (Rallus obsoletus obsoletus; hereafter, California rail), a federally and state-listed species, and restoration of tidal marsh ecosystems in the San Francisco Bay estuary provide a prime example of habitat restoration that has conflicted with species conservation. On the brink of extinction from habitat loss and degradation, and non-native predators in the 1990s, California rail populations responded positively to introduction of a non-native plant, Atlantic cordgrass (Spartina alterniflora). California rail populations were in substantial decline when the non-native Spartina was initially introduced as part of efforts to recover tidal marshes. Subsequent hybridization with the native Pacific cordgrass (Spartina foliosa) boosted California rail populations by providing greater cover and increased habitat area. The hybrid cordgrass (S. alterniflora × S. foliosa) readily invaded tidal mudflats and channels, and both crowded out native tidal marsh plants and increased sediment accretion in the marsh plain. This resulted in modification of tidal marsh geomorphology, hydrology, productivity, and species composition. Our results show that denser California rail populations occur in invasive Spartina than in native Spartina in San Francisco Bay. Herbicide treatment between 2005 and 2012 removed invasive Spartina from open intertidal mud and preserved foraging habitat for shorebirds. However, removal of invasive Spartina caused substantial decreases in California rail populations. Unknown facets of California rail ecology, undesirable interim stages of tidal marsh restoration, and competing management objectives among stakeholders resulted in management planning for endangered species or ecosystem restoration that favored one goal over the other. We have examined this perceived conflict and propose

  19. Endangered species management and ecosystem restoration: finding the common ground

    Directory of Open Access Journals (Sweden)

    Michael L. Casazza

    2016-03-01

    Full Text Available Management actions to protect endangered species and conserve ecosystem function may not always be in precise alignment. Efforts to recover the California Ridgway's Rail (Rallus obsoletus obsoletus; hereafter, California rail, a federally and state-listed species, and restoration of tidal marsh ecosystems in the San Francisco Bay estuary provide a prime example of habitat restoration that has conflicted with species conservation. On the brink of extinction from habitat loss and degradation, and non-native predators in the 1990s, California rail populations responded positively to introduction of a non-native plant, Atlantic cordgrass (Spartina alterniflora. California rail populations were in substantial decline when the non-native Spartina was initially introduced as part of efforts to recover tidal marshes. Subsequent hybridization with the native Pacific cordgrass (Spartina foliosa boosted California rail populations by providing greater cover and increased habitat area. The hybrid cordgrass (S. alterniflora à - S. foliosa readily invaded tidal mudflats and channels, and both crowded out native tidal marsh plants and increased sediment accretion in the marsh plain. This resulted in modification of tidal marsh geomorphology, hydrology, productivity, and species composition. Our results show that denser California rail populations occur in invasive Spartina than in native Spartina in San Francisco Bay. Herbicide treatment between 2005 and 2012 removed invasive Spartina from open intertidal mud and preserved foraging habitat for shorebirds. However, removal of invasive Spartina caused substantial decreases in California rail populations. Unknown facets of California rail ecology, undesirable interim stages of tidal marsh restoration, and competing management objectives among stakeholders resulted in management planning for endangered species or ecosystem restoration that favored one goal over the other. We have examined this perceived conflict

  20. A technique for the management of screw access opening in cement-retained implant restorations

    Directory of Open Access Journals (Sweden)

    Hamid Kermanshah

    2014-01-01

    Full Text Available Introduction: Abutment screw loosening has been considered as a common complication of implant-supported dental prostheses. This problem is more important in cement-retained implant restorations due to their invisible position of the screw access opening. Case Report: This report describes a modified retrievability method for cement-retained implant restorations in the event of abutment screw loosening. The screw access opening was marked with ceramic stain and its porcelain surface was treated using hydrofluoric acid (HF, silane, and adhesive to bond to composite resin. Discussion: The present modified technique facilitates screw access opening and improves the bond between the porcelain and composite resin.

  1. Using plant functional traits to guide restoration: A case study in California coastal grassland

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Corbin, Jeffrey; Krupa, Monica

    2011-01-01

    Restoration ecology can benefit greatly from developments in trait-based ecology that enable improved predictions of how the composition of plant communities will respond to changes in environmental conditions. Plant functional traits can be used to guide the restoration of degraded habitats by...... generally from the treatments. Carbon addition led to large intraspecific trait shifts, with individuals in C addition plots having smaller, denser leaves and shorter stature. Species' trait plasticity, however, was not related to the community composition response to C addition.   Our study indicates that...

  2. Clinical comparison of various esthetic restorative options for coronal build-up of primary anterior teeth

    Directory of Open Access Journals (Sweden)

    Himanshu Duhan

    2015-01-01

    Full Text Available Background: This study was designed to compare the clinical performance of composite, strip crowns, biological restoration, and composite with stainless steel band when used for the coronal build-up of anterior teeth. Materials and Methods: A total of 20 patients aged 3-6 years presenting with mutilated primary anterior teeth due to caries or trauma were selected for the study using randomized simple sampling. A total of 52 primary anterior teeth were randomly divided into four equal groups having 13 teeth in each group. Teeth in Group I were restored with composite, in Group II with strip crowns, in Group III with biologic restoration and with stainless steel band reinforced composite in group IV. The restorations were evaluated for color match, retention, surface texture, and anatomic form according to Ryge′s Direct (US Public Health Service evaluation criteria at baseline (immediate postoperative, after 48 h, 3, 6, and 9 months. The data obtained were statistically analyzed using Chi-square test, and level of significance, that is, P value was determined. Results: At baseline, none of the groups showed any color changes. Other than Group III all other groups showed highly significant changes (P 0.05. Deterioration in surface texture was exhibited maximum by restorations in Group IV followed by Group I at 3 months. Whereas, no surface changes were seen in Group II and III. Only Group I and IV showed discontinuity in anatomic form after 3 months. After 6 months, except in Group II, discontinuity in anatomic form was observed in all the groups. Discontinuity in anatomic form was seen in all the 4 groups after 9 months although the difference was not significant (P > 0.05. Conclusion: Biological restoration was found to be most satisfying esthetically owing to color compatibility with the patient′s tooth. Thus, it has a great potential to be used as esthetic restorative option in primary anteriors.

  3. A proposal of microtomography evaluation for restoration interface gaps

    Directory of Open Access Journals (Sweden)

    Deborah Meleo

    2012-01-01

    Full Text Available Nowadays, several adhesive systems are used in dental restoration and they’re evaluated by clinical research. In vitro evaluations are often made by means of traditional observation techniques (for example scanning electron microscope (SEM, while 3D cone-beam microtomography technique (3D micro-CT, that can be able to generate 3D sample images without any sample treatment during acquisition data, is going to be used a lot in the next few years. In dental cavity restored with composite, it is possible to predict the presence of gaps due to polymerization shrinkage; that is the reason this work purpose is to reveal by 3D images and measure by micro-CT analysis the voids generated applying the most used adhesive systems at the moment. By means of microtomographic analysis is proposed an aid to overcome bidimensional SEM investigation limits like random observation of sample surface, sample sectioning (to see inside it with the relative possible structural alterations induced on the same sample and the gold sputtering treatment. For this experimental work, human crown teeth have been selected, all restored with the same composite material, using five adhesive systems. After about 48 hours each tooth has been acquired by means of Skyscan 1072 micro-CT instrument and then processed by 3D reconstruction and micro-CT analyser software. Three adhesive systems have showed 3D micro-CT images with not as much voids as expected, with a very little extent. This kind of micro-CT in vitro evaluation proposal suggests a method to observe and quantify the voids generated after polymerization shrinkage during tooth restoration.

  4. Resin composite or ceramic inlays/onlays in posterior permanent teeth : a review of the literature

    OpenAIRE

    Breistrand, Joakim Lund; Juliussen, Øyvind

    2011-01-01

    Objective: To compare the clinical survival and long-term costs of extensive composite restorations to ceramic inlays and onlays. The hypothesis was that ceramic inlays and onlays can be more tooth substance saving and long-term economic for the patient than composite restorations. Methods: The dental literature, predominantly since 1990, was reviewed for prospective clinical studies of longevity of ceramic inlays/onlays and direct composite restorations in permanent posterior teeth. Only ...

  5. Three-dimensional finite element analysis of stress distribution in inlay-restored mandibular first molar under simultaneous thermomechanical loads.

    Science.gov (United States)

    Çelik Köycü, Berrak; Imirzalioğlu, Pervin; Özden, Utku Ahmet

    2016-01-01

    Functional occlusal loads and intraoral temperature changes create stress in teeth. The purpose of this study was to evaluate the impact of simultaneous thermomechanical loads on stress distribution related to inlay restored teeth by three-dimensional finite element analysis. A mandibular first molar was constructed with tooth structures, surrounding bone and inlays of Type II gold alloy, ceramic, and composite resin. Stress patterns on the restorative materials, adhesive resin, enamel and dentin were analyzed after simulated temperature changes from 36°C to 4 or 60°C for 2 s with 200-N oblique loading. The results showed that the three types of inlays had similar stress distribution in the tooth structures and restorative materials. Concerning the adhesive resin, the composite resin inlay model exhibited lower stresses than ceramic and gold alloy inlays. Simultaneous thermomechanical loads caused high stress patterns in inlay-restored teeth. Composite resin inlays may be the better choice to avoid adhesive failure. PMID:27041006

  6. Effects of river restoration on riparian biodiversity in secondary channels of the Pite River, Sweden.

    Science.gov (United States)

    Helfield, James M; Engström, Johanna; Michel, James T; Nilsson, Christer; Jansson, Roland

    2012-01-01

    Between 1850 and 1970, rivers throughout Sweden were channelized to facilitate timber floating. Floatway structures were installed to streamline banks and disconnect flow to secondary channels, resulting in simplified channel morphologies and more homogenous flow regimes. In recent years, local authorities have begun to restore channelized rivers. In this study, we examined the effects of restoration on riparian plant communities at previously disconnected secondary channels of the Pite River. We detected no increase in riparian diversity at restored sites relative to unrestored (i.e., disconnected) sites, but we did observe significant differences in species composition of both vascular plant and bryophyte communities. Disconnected sites featured greater zonation, with mesic-hydric floodplain species represented in plots closest to the stream and mesic-xeric upland species represented in plots farthest from the stream. In contrast, restored sites were most strongly represented by upland species at all distances relative to the stream. These patterns likely result from the increased water levels in reconnected channels where, prior to restoration, upland plants had expanded toward the stream. Nonetheless, the restored fluvial regime has not brought about the development of characteristic flood-adapted plant communities, probably due to the short time interval (ca. 5 years) since restoration. Previous studies have demonstrated relatively quick responses to similar restoration in single-channel tributaries, but secondary channels may respond differently due to the more buffered hydrologic regimes typically seen in anabranching systems. These findings illustrate how restoration outcomes can vary according to hydrologic, climatic and ecological factors, reinforcing the need for site-specific restoration strategies. PMID:22042408

  7. Environmental restoration project configuration control

    International Nuclear Information System (INIS)

    Projecting budget requirements for performing environmental restoration activities in a manner consistent with the regulatory agencies requires long-term planning, scheduling, and budget forecasting. The Westinghouse Idaho Nuclear Company, Inc. (WINCO) Environmental Restoration Program is responsible for 14 operable units at the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory (INEL). To facilitate response to US Department of Energy (DOE) requirements, a baseline document has been established, and activities for each of the environmental release sites have been developed. The baseline document is based primarily on the activities identified in the Interagency Agreement (IAG) for operable unit scoping and investigation. In addition, the schedule for some sites reflects fiscal year 1991 Consent Order Compliance Agreement requirements. Planning has been conducted through completion of the Record of Decision. The baseline document provides management with a defensible basis to project and control costs. Work that requires modification in scope, changes to applicable DOE or regulatory orders/guidance, or identification of additional release sites will normally impact costs and schedule. The impact of these changes will be evaluated and the baseline revised to reflect the changes. Management can use the baseline to evaluate potential cost impacts and assist with decision making when resources are limited to select the optimal technical strategy and minimize the impact to cost and schedule for other projects

  8. Nonthermal Atmospheric Plasmas in Dental Restoration.

    Science.gov (United States)

    Liu, Y; Liu, Q; Yu, Q S; Wang, Y

    2016-05-01

    It is well known that the service life of contemporary composite restoration is unsatisfactory, and longevity of dentin bonding is one of the major culprits. Bonding is essentially a hybridization process in which dental substrate and adhesive resin interact with each other through an exchange process. Thus, the longevity of dentin bonding can only be improved with enhanced qualities in substrate, adhesive resin, and their interaction within the hybridization zone. This review aims to collect and summarize recent advances in utilizing nonthermal atmospheric plasmas (NTAPs)-a novel technology that delivers highly reactive species in a gaseous medium at or below physiologic temperature-to improve the durability of dentin bonding by addressing these 3 issues simultaneously. Overall, NTAP has demonstrated efficacies in improving a number of critical properties for dentin bonding, including deactivation of oral pathogens, modification of surface chemistry/properties, resin polymerization, improvement in adhesive-dentin interactions, and establishment of auxiliary bonding mechanism. While a few preliminary studies have indicated the benefit of NTAP to bond strength and stability, additional researches are warranted to employ knowledge acquired so far and to evaluate these properties in a systematic way. PMID:26848068

  9. Biocompatibility of composite resins

    OpenAIRE

    Sayed Mostafa Mousavinasab

    2011-01-01

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

  10. Habitat restoration: Early signs and extent of faunal recovery relative to seagrass recovery

    Science.gov (United States)

    McSkimming, Chloe; Connell, Sean D.; Russell, Bayden D.; Tanner, Jason E.

    2016-03-01

    The overall intent of restoration is often not only to restore the habitat per se, but to restore the ecosystem services it supplies, and particularly to encourage the return of fauna. Seagrass meadows act as habitat for some of the most diverse and abundant animal life, and as the global loss of seagrass continues, managers have sought to restore lost meadows. We tested how quickly the epifaunal richness, abundances and community composition of experimental restoration plots recovered to that in an adjacent natural seagrass meadow relative to the recovery of seagrass per se. Seagrass structure in the restoration plots took three years to become similar to a nearby natural meadow. The recovery of epifaunal richness and total abundance, however, occurred within one year. These results suggest that although recovering habitats may not be structurally similar to undisturbed habitats, they can support similar richness and abundances of epifauna, and thus have greater economic and social value than otherwise might have been expected. Nevertheless, whilst epifaunal richness and total abundance recovered prior to the recovery of seagrass structure, full recovery of seagrass was required before the composition and relative abundances of the epifaunal community matched that of the natural seagrass meadow.

  11. Evaluation of resins for provisional restorations.

    Science.gov (United States)

    Burgess, J O; Haveman, C W; Butzin, C

    1992-06-01

    An in vivo study of two resin materials (Barricaid and Caulk Temporary Crown and Bridge Resin) was done to determine the retention, post-operative sensitivity, and fabrication time of provisional restorations made from these materials. Following the placement of these resins in 67 intracoronal cavity preparations of 19 adult patients, a baseline evaluation was made which included a clinical examination and color slides. Twenty-four hours after the temporary restorations were placed, the patients completed evaluations of the post-operative sensitivity experienced. There was no difference in post-operative sensitivity between the teeth restored with Barricaid or Caulk Temporary Crown and Bridge Resin. At the insertion appointment of the final restoration, the interim restoration's success rate was determined. There was no difference between the retention of the two provisional materials. Fabrication time was significantly different with Barricaid restorations requiring less than one-half the fabrication time of the Caulk Temporary Crown and Bridge Resin material. PMID:1388950

  12. Evaluating the process of ecological restoration

    Directory of Open Access Journals (Sweden)

    Christer Nilsson

    2016-03-01

    Full Text Available We developed a conceptual framework for evaluating the process of ecological restoration and applied it to 10 examples of restoration projects in the northern hemisphere. We identified three major phases, planning, implementation, and monitoring, in the restoration process. We found that evaluation occurred both within and between the three phases, that it included both formal and informal components, and that it often had an impact on the performance of the projects. Most evaluations were short-term and only some parts of them were properly documented. Poor or short-term evaluation of the restoration process creates a risk that inefficient methods will continue to be used, which reduces the efficiency and effectiveness of restoration. To improve the restoration process and to transfer the knowledge to future projects, we argue for more formal, sustained evaluation procedures, involving all relevant stakeholders, and increased and improved documentation and dissemination of the results.

  13. Evaluation of the fracture resistance of remaining thin-walled roots restored with different post systems

    Directory of Open Access Journals (Sweden)

    Luis Gustavo Nunes Dias Pinho

    2013-10-01

    Full Text Available The purpose of this work was evaluating the fracture strength of bovine roots weakened experimentally, restored with two different techniques: internal reinforcement of root canal walls with composite resin and a cast metal post and core or anatomic post (glass fiber post associated with composite resin. Thirty bovine lower central incisive were selected and transversally sectioned, remaining 14 mm of root in order to approximate to the human maxillary central incisive.  A sequence of standardized wear was used to weak the root until the walls remaining achieved from 0.5 to 0.7 mm of thickness at the cervical edge. Two groups were separated randomly (n=15 in order to test the roots reinforced with composite resin associated with cast metal post and core (CMP, or roots restored with composite resin associated to the glass fiber post (GFP. The test were applied in a Universal Test Machine (EMIC with tangential compressive loading focused on the lingual face of core in an angle of 135° with the long axis of the tooth at a crosshead speed of 0.5 mm/min until failure occurred. The results showed that the fracture strength of remaining roots with weakened walls was influenced by the restorative technique, and the higher values of strength fractures were observed in the group of roots reinforced by composite resin associated with CMP (p<0.001 when compared to the group of roots restored with anatomic post.

  14. Evaluating tooth restorations: micro-computed tomography in practical training for students in dentistry

    Science.gov (United States)

    Deyhle, Hans; Schmidli, Fredy; Krastl, Gabriel; Müller, Bert

    2010-09-01

    Direct composite fillings belong to widespread tooth restoration techniques in dental medicine. The procedure consists of successive steps, which include etching of the prepared tooth surface, bonding and placement of composite in incrementally built up layers. Durability and lifespan of the composite inlays strongly depend on the accurate completion of the individual steps to be also realized by students in dental medicine. Improper handling or nonconformity in the bonding procedure often lead to air enclosures (bubbles) as well as to significant gaps between the composite layers or at the margins of the restoration. Traditionally one analyzes the quality of the restoration cutting the tooth in an arbitrarily selected plane and inspecting this plane by conventional optical microscopy. Although the precision of this established method is satisfactory, it is restricted to the selected two-dimensional plane. Rather simple micro computed tomography (μCT) systems, such as SkyScan 1174™, allows for the non-destructive three-dimensional imaging of restored teeth ex vivo and virtually cutting the tomographic data in any desired direction, offering a powerful tool for inspection of the restored tooth with micrometer resolution before cutting and thus also to select a two-dimensional plane with potential defects. In order to study the influence of the individual steps on the resulted tooth restoration, direct composite fillings were placed in mod cavities of extracted teeth. After etching, an adhesive was applied in half of the specimens. From the tomographic datasets, it becomes clear that gaps occur more frequently when bonding is omitted. The visualization of air enclosures offers to determine the probability to find a micrometer-sized defect using an arbitrarily selected cutting plane for inspection.

  15. River restoration success: a question of perception.

    Science.gov (United States)

    Jähnig, S C; Lorenz, A W; Hering, D; Antons, C; Sundermann, A; Jedicke, E; Haase, P

    2011-09-01

    What defines success and failure of river restoration measures is a strongly debated topic in restoration science, but standardized approaches to evaluate either are still not available. The debate is usually centered on measurable parameters, which adhere to scientific objectivity. More subjective aspects, such as landscape aesthetics or recreational value, are usually left out, although they play an important role in the perception and communication of restoration success. In this paper, we show that different perceptions of restoration success exist by analyzing data from 26 river restoration measures in Germany. We addressed both objective parameters, such as hydromorphological changes and changes in fish and benthic invertebrate assemblages, from field investigations, and subjective parameters, such as opinions and perceptions, from water managers via an online survey. With regard to the objective hydromorphological and biotic parameters, our results agree with many studies that have reported improvements in the hydromorphology following restoration; however, there is no similar agreement between results concerning changes in the benthic invertebrate and fish assemblages. The objective results do not correspond to the subjective parameters because self-evaluation of the restoration projects by water managers was overly positive. Indeed, 40% of the respondents admitted that their evaluation was based on gut feeling, and only 45% of the restoration measures were monitored or occasionally checked. This lack of objectively recorded data meant that the water managers were not able to reasonably evaluate restoration success. In contrast, some self-evaluation responses reflected a different perception of the restoration success that was based on landscape aesthetic values or on benefit for the public; others adopted a general "condemned to success" attitude. Based on our data, we argue (1) that goals should be thoughtfully formulated prior to restoration

  16. Restorative justice within the criminal justice system

    OpenAIRE

    Vasiljević-Prodanović Danica

    2010-01-01

    Positioning of restorative justice within the criminal justice system is one of the current questions preoccupying theorists and practitioners in the field. During decades restorative justice processes have been predominantly used within juvenile justice systems for dealing with minor offences committed by juveniles. Number of jurisdictions in Europe, USA, Canada, Australia have criminal codifications containing provisions that enable use of restorative justice processes in aim of diver...

  17. Atraumatic restorative treatment in atypical cavities

    OpenAIRE

    Letícia Simino Carvalho; Janaina Merli Aldrigui; Clarissa Calil Bonifácio; José Carlos Pettorossi Imparato; Daniela Prócida Raggio

    2009-01-01

    The atraumatic restorative treatment has been widely divulged among professionals in the area of Pediatric Dentistry. This restorative technique is included in the philosophy of Minimal Intervention and is considered one of the most conservative treatments, because only the layer of infected dentin caries is removed. Moreover, the atraumatic restorative treatment has been shown to be less painful than conventional approaches, and local anesthesia is rarely required. After the removal of the i...

  18. Enhanced aesthetics with all ceramics restoration

    OpenAIRE

    Sanjna Nayar; Aruna, U.; Wasim Manzoor Bhat

    2015-01-01

    The demand for the dentist to achieve excellence in esthetics and function has driven modern advances in materials and restoration fabrication. The development of various casting alloys and precise casting systems has contributed to the successful use of metal-based restorations. However, patient requests for more aesthetic and biologically "safe" materials that have led to an increased demand for metal-free restorations. The following case presentation illustrates a successful aesthetic and ...

  19. Can Viral Videos Help Beaver Restore Streams?

    Science.gov (United States)

    Castro, J. M.; Pollock, M. M.; Lewallen, G.; Jordan, C.; Woodruff, K.

    2015-12-01

    Have you watched YouTube lately? Did you notice the plethora of cute animal videos? Researchers, including members of our Beaver Restoration Research team, have been studying the restoration potential of beaver for decades, yet in the past few years, beaver have gained broad acclaim and some much deserved credit for restoration of aquatic systems in North America. Is it because people can now see these charismatic critters in action from the comfort of their laptops? While the newly released Beaver Restoration Guidebook attempts to answer many questions, sadly, this is not one of them. We do, however, address the use of beaver (Castor canadensis) in stream, wetland, and floodplain restoration and discuss the many positive effects of beaver on fluvial ecosystems. Our team, composed of researchers from NOAA National Marine Fisheries Service, US Fish and Wildlife Service, US Forest Service, and Portland State University, has developed a scientifically rigorous, yet accessible, practitioner's guide that provides a synthesis of the best available science for using beaver to improve ecosystem functions. Divided into two broad sections -- Beaver Ecology and Beaver Restoration and Management -- the guidebook focuses on the many ways in which beaver improve habitat, primarily through the construction of dams that impound water and retain sediment. In Beaver Ecology, we open with a discussion of the general effects that beaver dams have on physical and biological processes, and we close with "Frequently Asked Questions" and "Myth Busters". In Restoration and Management, we discuss common emerging restoration techniques and methods for mitigating unwanted beaver effects, followed by case studies from pioneering practitioners who have used many of these beaver restoration techniques in the field. The lessons they have learned will help guide future restoration efforts. We have also included a comprehensive beaver ecology library of over 1400 references from scientific journals

  20. Review: Mangrove ecosystem in Java: 2. Restoration

    OpenAIRE

    PURIN CANDRA PURNAMA; KUSUMO WINARNO; AHMAD DWI SETYAWAN

    2004-01-01

    R E V I E W:Ekosistem Mangrove di Jawa: 2. RestorasiThe restoration of mangroves has received a lot of attentions world wide for several reasons. Mangrove ecosystem is very important in term of socio-economic and ecology functions. Because of its functions, wide range of people paid attention whenever mangrove restoration taken place. Mangrove restoration potentially increases mangrove resource value, protect the coastal area from destruction, conserve biodiversity, fish production and both o...