Eighteen-month clinical performance of preheated nanoceramic resin-based composites in Class I occlusal cavities: A randomized clinical trial.

Aims: This study aimed to evaluate the effect of preheated nanoceramic resin-based composite (RBC) (Ceram-X-Mono) placed in Class I occlusal cavities over a period of 18 months. Settings and Design: This study involves split-mouth design, randomized controlled clinical trial (RCT). Materials and Methods: One operator restored 60 Class I occlusal cavities in 24 patients. Preheating of nanoceramic RBC to 60°C for 10 min was performed before insertion of the material into 30 prepared cavities, whereas 30 restorations in the nonpreheated group were placed according to the manufacturer's instructions. Two observers evaluated the restorations using Federation Dentaire Internationale (FDI) criteria at baseline, 6, 12, and 18 months. Statistical Analysis: Kappa index, Friedman and Wilcoxon matched pair test, and Krushal-Wallis and Mann-Whitney tests were used for statistical analysis. Results: 100% retention rates were seen in both the groups. In nonpreheated group, significant difference was observed for surface staining (P = 0.0001), color stability (P = 0.0277), anatomic form (P = 0.0431), and marginal adaptation (P = 0.0051), whereas in preheated group, significant increase in surface staining (P = 0.0051) was recorded. There was a statistically significant difference observed between the preheated and nonpreheated groups at different time periods for the tested clinical parameters. Conclusion: Within the limitations of this RCT of 18 months, preheated nanoceramic RBC restorations showed better clinical performance compared to nonpreheated group.

Effect of Fluoride Recharge on the Microleakage of Fluoride-Releasing Restorative Materials: An Ex Vivo Confocal Laser Scanning Microscopy Study.

Context: Success or failure of a restoration depends on its ability to bond to the tooth structure, to reduce microleakage, and to inhibit secondary caries. Fluoride-releasing materials have the inherent potential to release fluoride and are also capable of recharging themselves with topical agents. Aim: The aim of this study was to compare and evaluate the effect of fluoride recharge on microleakage of different restorative materials. Materials and Methods: Eighty extracted teeth were collected and split mesiodistally into 160 specimens. Class V cavities were prepared on buccal and lingual surfaces. Specimens were divided into four groups of 40 each based on the restorative material. Group I: Glass ionomer; Group II: Resin composite; Group III: Giomer; and Group IV: Alkasite. The restored teeth were stored in artificial saliva. Each group was divided into four subgroups for fluoride recharge and subsequent confocal laser scanning microscopy (CLSM) examination: (A) no fluoride recharge and CLSM examination after 24 h, (B) no fluoride recharge and CLSM examination after 3 weeks, (C) fluoride recharge once at third week followed by CLSM examination at 6 weeks, and (D) fluoride recharge twice at third week and sixth week followed by CLSM examination at 9 weeks. Statistical Analysis: Kruskal-Wallis and Mann-Whitney U tests were performed to analyze the obtained data. Results: A significant difference in microleakage was noted among resin composite and other groups except Cention-N, whereas no significant difference was noted pre- and post-fluoride recharge. Conclusion: Increased microleakage was noted post-fluoride recharge, although statistically not significant.

Influence of "MOTRCS" factors on the performance of various direct and indirect restorations: A finite element analysis.

AIM OF THE STUDY: The purpose of the study is to evaluate the occlusal relationship of the mesiobuccal cusp of a mandibular first molar with the marginal ridge of maxillary first molar and second premolar and to analyze the effect of the above occlusal relation on different direct and indirect restorations using finite element analysis (FEA). METHODOLOGY: Four hundred volunteers studying in a dental college were screened, of which 100 volunteers were selected for studying occlusal relationships based on the inclusion and exclusion criteria. The two most common occlusal relationships were considered for analyzing two direct (amalgam and direct composite restorations) and two indirect restorations (composite and ceramic restorations). Three-dimensional (3D) scanning of the models was performed, and Class II tooth preparations specific for each restorative material were prepared digitally on 3D models. FEA was employed to study von Mises (VM) stress, principal stresses, and cuspal deflection for each restorative material, and failure of the tooth-restoration unit was calculated using the modified Mohr failure criterion. RESULTS: Among all the analyzed materials, cuspal deformation, principal stresses, and VM stresses were high for direct composite restoration and least for ceramic inlay. According to modified Mohr criteria, except for direct composite, all other materials performed better. CONCLUSION: Silver amalgam and ceramic restorations presented with minimal stress concentration and cuspal deflection, and Type I occlusal relationship presented with higher stress concentration compared to Type II.

Stereomicroscopic Dye Leakage Measurement of Six Different Root Canal Sealers.

INTRODUCTION: Hermetic sealing of the root canal is the most desirable outcome of any root canal treatment, but almost always the filling of the root canal is defective, which is a multifactorial outcome. One such factor majorly influencing the obturation is the root canal sealer used. AIM: The present study was done for evaluating microleakage in different root canal sealers. MATERIALS AND METHODS: Sixty extracted human single rooted teeeth were used in this in-vitro study. Sealers tested for microleakage in this study were zinc oxide eugenol based sealer, Sealapex, AH Plus, MTA Plus, EndoRez, Endosequence BC. All the specimens were examined under stereomicroscope for microleakage and the obtained data were statistically analysed using One-way ANOVA test and Tukey's multiple comparision tests using the software GraphPad Prism 7.02. RESULTS: The Endosequence BC group showed the least dye leakage and the highest leakage was seen in Zinc oxide Eugenol based sealer. CONCLUSION: Bio ceramic salers being hydrophilic show better sealing ability compared to resin based and eugenol based sealers.

Effect of Different Anti-Oxidants on Shear Bond Strength of Composite Resins to Bleached Human Enamel.

INTRODUCTION: The bond strength of the composite to the bleached enamel plays a very important role in the success and longevity of an aesthetic restoration. AIM: The aim of this study was to compare and evaluate the effect of Aloe Vera with 10% Sodium Ascorbate on the Shear bond strength of composite resin to bleached human enamel. MATERIALS AND METHODS: Fifty freshly extracted human maxillary central incisors were selected and divided into 5 groups. Group I and V are unbleached and bleached controls groups respectively. Group II, III, IV served as experimental groups. The labial surfaces of groups II, III, IV, V were treated with 35% Carbamide Peroxide for 30mins. Group II specimens were subjected to delayed composite bonding. Group III and IV specimens were subjected to application of 10% Sodium Ascorbate and leaf extract of Aloe Vera following the Carbamide Peroxide bleaching respectively. Specimens were subjected to shear bond strength using universal testing machine and the results were statistically analysed using ANOVA test. Tukey (HSD) Honest Significant Difference test was used to comparatively analyse statistical differences between the groups. A p-value <0.05 is taken as statistically significant. RESULTS: The mean shear bond strength values of Group V showed significantly lower bond strengths than Groups I, II, III, IV (p-value <0.05). There was no statistically significant difference between the shear bond strength values of groups I, II, III, IV. CONCLUSION: Treatment of the bleached enamel surface with Aloe Vera and 10% Sodium Ascorbate provided consistently better bond strength. Aloe Vera may be used as an alternative to 10% Sodium Ascorbate.