Purpose: The purpose of this in vitro study was to evaluate the tensile bond strength of sealants in primary molars after the surface pretreatment with an Er:YAG laser.
Methods: Thirty primary molars were selected, and their roots were removed. Crowns were embedded in polyester resin and enamel surfaces were flattened. The bonding site was delimited, and samples were randomly assigned to 3 groups according to the surface pretreatment: (1) group 1=37% phosphoric acid; (2) group 2=Er:YAG laser; and (3) group 3=Er:YAG laser+37% phosphoric acid. Specimens were adapted to a metallic device, a split matrix was positioned on the surface of each sample and the FluroShield sealant was inserted into the matrix with a Centrix injector". Samples were stored for 48 hours, thermocycled, and subjected to a bond strength test (50 Kgf at 0.5 mm/minute).
Results: Means in MPa (+/-SD) were: (1) group 1=10.80+/-3.28; (2) group 2=4.17+/-2.31; and (3) group 3=12.85+/-2.14. Analysis of variance and Tukey test revealed a statistical similarity between groups 1 (37% phosphoric acid) and 3 (Er:YAG laser+37% phosphoric acid). Treatment with the Er:YAG laser solely produced the lowest average and was statistically different from the other groups.
Conclusion: Conditioning with the Er:YAG laser may influence the sealant's bond strength; nevertheless, the subsequent application of acid is mandatory.