Dentin morphology and bond strength after conventional bleaching versus hybrid violet led technique

Abstract

The aesthetic demand in dentistry has grown worldwide, as the search for conventional dental bleaching which, although effective, can modifies physical and chemical proprieties of the dental element. Thus, new techniques, such as violet LED light, has been emerged and need further study. In order to analyze and compare the effects of violet LED light on dental structure, this study investigates the influence of bleaching on dentin morphology and bond strength in healthy human teeth with different dental bleaching techniques: Group A - Hydrogen Peroxide a 35% (1x per week for 4 weeks, 45 minutes of gel application); Group B - 35% hydrogen peroxide (1x per week for 4 weeks, 15 minutes of gel application); Group C - violet LED + 35% hydrogen peroxide (hybrid technique, 1x / week, for 4 weeks, 15 minutes of gel application); Group D - no bleaching technique (control). Samples will undergo microtensile test on the Universal Testing Machine (Kratos equipment, model IKCL3-USB, Sao Paulo, Brazil) at 0.5 mm / min and a 50 N load until fracture. Resistance values will be recorded in kN. Two examiners will perform a descriptive (qualitative) analysis of fracture pattern and a statistical analysis that will be done through one-way analysis of variance (ANOVA) and Tukey-Kramer test, considering 5% of the significance level. Additionally, 2 examples from each group (n = 2) will have their surface morphology analyzed by sweep electron microscopy (SEM), at predetermined times. SEM data will be analyzed descriptively (qualitative analysis), comparing the groups with each other. (AU)