Resumen de Evaluation of dental enamel microproperties after bleaching with 35% hydrogen peroxide and different light sources: an in vitro study
Alieny-Cristina-Duarte Ferreira, Ana-Luzia-Araújo Batista, José-de Alencar Fernandes-Neto, Thamyres-Maria-Silva Simões, Maria-das Graças-Barbosa da Silva, Daiane-Domingos de Barros, Josefa-Simere-dos Santos-Barros Catão, Tiago Almeida de Oliveira, Maria-Helena-Chaves-de Vasconcelos Catão
Background: To evaluate the tooth enamel surface morphology after the action of 35% hydrogen peroxide with and without LED activation.
Material and Methods: 70 bovine incisors with an enamel surface of 4x4x3 mm were used, prepared for reading superficial microhardness and roughness. Specimens were randomly distributed and divided into 7 experimental groups (n = 10); G1 = artificial saliva; G2 = 35% HP - 2 sessions (3x15´); G3 = Phosphoric Acid + 35% HP - 3 sessions (3x15´); G4 = 35% HP - 2 sessions (3x15´) + blue LED; G5 = 35% HP - 2 sessions (3x15´) + green LED;
G6 = 35% HP - 2 sessions (3x20´) + violet LED; G7 = Violet LED - 2 sessions (3x20´). The results were analyzed by the Anova, Wilcoxon, Dunnett and Tukey tests (α = 0.05).
Results: The G4 group showed a greater change in microhardness. Regarding roughness, the biggest mean difference between groups occurred in G2, G5 and G7. Optical microscopy showed a smooth enamel surface in groups G2, G5 and G7.
Conclusions: changes in the enamel surface were observed in relation to microhardness, but without significant changes in roughness, where the LED (green and violet) resulted in a smooth surface.
