RESUMO
Background: The background of this study was to improve the longevity of a restoration and optimal adaptation of restorative material to the prepared cavity walls is crucial. The study aimed to evaluate the interfacial adaptation of Activa, Micron, and Predicta bulk bioactive restorative materials to coronal dentin using micro-computed tomography (CT) analysis. Materials and Methods: In this in vitro micro-CT assessment study, Class II mesio- and disto-occlusal cavities were prepared on 60 extracted human mandibular molar teeth. After etching and bonding procedures, all the mesial cavities (n = 60) were restored with Tetric N-Ceram and the disto-occlusal cavities with Activa or Micron or Predicta bioactive (n = 20 each) restoratives. Interfacial gap percentages were evaluated under micro-CT before (baseline) and after thermo-mechanical load cycling (TMC). Acquired data were analyzed statistically using one-way analysis of variance, Paired t-test, and Tukey's multiple post hoc procedures, at P < 0.05 level of significance. Results: The interfacial gap percentages were lowest for Predicta bioactive and highest for the Micron group (P < 0.05). The number of gaps increased significantly after TMC in all the groups (P < 0.05). The adaptation of tested materials was inferior to axial wall and pulpal floor, whereas considerably better adaptation was observed on buccal and lingual walls. Conclusion: Predicta bioactive followed by Activa bioactive has shown superior interfacial adaptation, whereas Micron bioactive demonstrated maximum microgaps compared to nanohybrid composite. Artificial aging with TMC has a negative influence on the internal adaptation of all tested materials.
RESUMO
AIM AND OBJECTIVE: To evaluate the synergistic effect of arginine on the remineralizing potential of fluoride varnish and nanohydroxyapatite. MATERIALS AND METHODS: A total of 100 teeth were taken; of them, 50 teeth were allotted for microhardness test and 50 teeth for scanning-electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) analysis. Fifty teeth used for hardness testing were sectioned to obtain 100 samples, and the baseline hardness values were measured. Samples were allotted into five groups (n = 20): group I: arginine; group II: fluoride varnish; group III: nanohydroxyapatite; group IV: arginine + fluoride varnish; group V: arginine + nanohydroxyapatite. Microhardness values were measured after 96 hours of demineralization and then again after application of remineralizing agents (pH cycling) for 10 days to check for gain in microhardness. The other 50 samples were subjected to SEM-EDX analysis for evaluating gain in the mineral content after demineralization and after application of the remineralizing agents. The collected data were subjected to statistical analysis using SPSS software version 22.0. RESULTS: The maximum mean microhardness values were observed in group IV and group V. There was no statistical significance between them. Similarly, maximum mineral gain was seen in groups IV and V. A significant increase in fluoride gain was seen in group IV. CONCLUSION: Arginine has a synergistic effect on remineralization potential of fluoride varnish and nanohydroxyapatite. CLINICAL SIGNIFICANCE: The incorporation of arginine into fluoride varnishes and nanohydroxyapatite significantly increased their remineralization potential.
