Influence of LEOand halogen lamp photopolymerization on the shear bond strength of bleached enamel

Abstract

This study evaluated the influence of LED photopolymeri- zation on enamel shear bond strength after bleaching with 10% carbamide peroxide. Sixty incisive bovine teeth were randomly divi- ded into 4 groups (n=15) according to bleaching treatment and photo- polymerization source used: G1 - Bleached IHalogen lamp; G2- Not bleached IHalogen lamp (control); G3 - Bleached I Light-emitting diodes (LED); G4 - Not bleached I Light-emitting diodes (LED) (control). Experimental groups were exposed to bleaching agent for a period of 14 days, with a daily contact of 4 hours. Control groups were stored in artificial saliva at 37Q C for the same period of bleaching treatment. Procedures for bonding composite resin to enamel were done according to manufacturer's instructions. After storage in distilled water at 37Q C for 24 hours, alI samples were submitted to shear bond testo The highest mean value (13,66 MPa) was associated to G2, while the lowest one (1l,61MPa) was asso- ciated to G4. The comparison of groups by 2-way ANOVA showed there was no significant difference for both factors considered in this study (bleaching and photopolyme- rization source), as well as for the interaction between them. There- fore, it was possible to conclude that enamel bleaching and the photopolymerization source used, had no influence on enamel shear bond strength.