Effect of tooth whitening with violet LED and peroxides on enamel stained with cigarette smoke, coffee or red wine solutions

Resumo

This study evaluate the effect of whitening with violet LED (LED) combined or not with 37% carbamide (CP) or 35% hydrogen peroxide on enamel stained with cigarette smoke (SK), coffee (CF) and red wine (RW). Bovine dental blocks were obtained and stained with extrinsic pigments (n=50): SK, CF, RW or control (C). Specimens were whitened following protocols: LED, LED/CP, CP, LED/HP or HP. Color change (DE) was measured considering after staining (T0), 24 hours elapsed from bleaching (TB) and 7 days after treatments (T7) times by means of spectrophotometry. Data was tested by two-way ANOVA and Tukey’s Test. Enamel’s surface morphology was analysed under scanning electron microscope (SEM). Regardless of the extrinsic pigment, LED promoted statistically greater DE for stained groups in comparison to C (p<0,05). LED alone promoted clinical perceptible DE, but in less extent than for gels. LED/CP DE was significanty greater than CP’s for CF, RW and C (p<0.05). Equal DE was found for LED/CP and HP for all pigments (p>0.05), but for CF (p=0,020). LED/HP DE was significantly higher than HP only for CF (p=0.012). Outcomes were mantained after seven days. Topography of enamel suffered alterations under peroxides, but this was not exacerbated by LED irradiation. Effectiveness of LED alone on tooth whitening is enhanced in the presence of extrinsic pigments. Violet LED influenced effectiveness of CP and HP depending on staining type. LED did not change patterns of enamel surface morphology.