Efecto de dos agentes de aclaramiento sobre la microdureza superficial de una resina compuesta

Objetivo: To compare the effect of two whitening agents on the surface microhardness of a composite resin. Methodology: Experimental, cross-sectional, comparative and prospective study, the microhardness of 30 nanofilled composite resin discs (FiltekTM Z350 XT, 3M ESPE, USA) was evaluated before and after the use of whitening agents. The design consisted of three experimental groups, a control group, a group with 16% carbamide peroxide, and another with 35% hydrogen peroxide. Results: The greatest reduction in microhardness was found in the group to which the 35% hydrogen peroxide bleaching agent was applied. It was also found that when comparing the average of the difference in microhardness before and after the application of the lightening and control agents, a statistically sig-nificant difference (<0.001) was obtained between these groups with the ANOVA test. And after applying Tukey’s post hoc test, statistically significant differences could be obtained between 16% carbamide peroxide and the control (<0.001); as well as between 35% hydrogen peroxide and control (<0.001). Conclusion: the microhardness of the composite resins was influenced, decreasing significantly by both dental whitening procedures used in the present study.