Influence of Er,Cr:YSGG Laser on Bond Strength of Self-Etching System

Objectives: The purpose of this in vitro study was to evaluate the influence of Er,Cr:YSGG (2,78μm) laser irradiation on tensile bond strength of a self-etching system (Clearfill SE Bond) to enamel and dentin. Methods: Twenty recently extracted third human molars were selected. The roots were separated and the crowns were cut in mesio-distal sense and polyshed flat until enamel or dentin exposure. The teeth were randonly divided into four groups (n=10): G1(enamel-control) standardized bur cutt with cylinder diamond bur + self-etching system (SE); G2 enamel conditioning with Er,Cr:YSGG laser (Millenium Biolase Technology)+ SE; G3 (dentin-control) standardized bur cutt with cylinder diamond bur + SE, G4 dentin conditioning with Er,Cr:YSGG laser +SE. The settings tested were the suggested by the manufacturer: 2,5 W, 20 Hz, calculated fluency 16 J/cm2 at 2 mm of working distance for both substrates. All samples were restored with composite resin Z-250. After storage in distilled water 37ºC-24h, the teeth were submitted to tensile bond strength test (50Kgf and 0,5mm/min). Results: The obtained results (Mpa) were submitted to ANOVA and Tukey test (p<0,05) (groups identified with the same letter are not statistically significant different): G1-20.66 ±2.78 (a), G2- 11.24 ±2.90 (b), G3- 15.12 ±3.95 (c) e G4 7.78±2.61 (d). Conclusions: At the setting used, enamel and dentin conditioning with Er,Cr:YSGG laser, negatively affected the adhesion of the self-etching adhesive system.