Résumé
Introduction: Remineralization as a treatment procedure has received a lot of attention both from clinicians as well as researchers. The objective of this study was to assess the effect of Remin Pro® on enamel microhardness after bleaching the teeth with McInnes bleaching agent using Vickers microhardness tester. Materials and Methods: In this study, freshly extracted ten central incisors were taken which were subjected to baseline indentation by using Vickers microhardness indenter and then McInnes bleaching solution was applied for 5 min to demineralize these teeth. Remin Pro a newer remineralizing agent was applied for 7 days, which showed an increase in microhardness at the end of 7 days. Results: The values were subjected for statistical analysis using paired t‑test. All the samples showed a decrease in the microhardness after bleaching with McInnes solution. The decrease in mean hardness from baseline to demineralization was found to be statistically significant (P < 0.001). However, remineralizing the same tooth with Remin Pro for 7 days, showed an increase in hardness, which was found to be statistically significant (P < 0.05). Conclusion: McInnes bleaching agent decreases the microhardness of enamel and Remin Pro® used in the study causes an increase in the microhardness of bleached enamel.
Résumé
Objective: To determine the effect of delayed light polymerization of a dual-cured composite base material on the marginal adaptation of class II composite restoration. Materials and Methods: 35 extracted human molar teeth were used to prepare class II mesio-occlusal or disto-occlusal slot preparations with gingival margins at the CEJ. The teeth were restored using an open-sandwich technique with a 2mm base increment of dual-cured composite, and divided into 5 groups based on the mode of the polymerization of the dual-cured composite base: Group A - self-cured after placement (5 mins), Group B - light-cured immediately after placement, Group C - light-cured 30 seconds after placement, Group D - light-cured 60 seconds after placement, Group E - light-cured 120 seconds after placement. Then a top layer of a light-cured composite resin is placed to complete the restoration. The teeth were thermocycled and immersed in 1% aqueous solution of methylene blue for 24 hours. Sectioning of the teeth and scoring under stereomicroscope was done. Data will be statistically evaluated using the kruskal wallis 1-way ANOVA. Results: Statistical analysis using kruskal wallis 1-way ANOVA showed that the dual-cured composite light polymerized 1 minute after placement exhibited the least microleakage. Conclusion: Delayed light polymerization of the dual-cured composite base reduced the microleakage in class II open-sandwich restorations.