The durability of adhesion to Er,Cr:YSGG laser-irradiated enamel.

Abstract

Adhesion durability of resin adhesives with Er,Cr:YSGG laser irradiated-enamel has been rarely investigated in the literature. Thus, the present study evaluated the influence of long-term water storage (12-month) on resin bond strength with the enamel irradiated with Er,Cr:YSGG laser irradiation deployed different settings. The flattened enamel samples of 35 bovine teeth, which were embedded into acrylic blocks, were randomly divided into 7 groups (n = 5), according to surface treatments using Er,Cr:YSGG laser with different parameters 6 W/20 Hz, 6 W/35 Hz, 6 W/50 Hz, 3 W/20 Hz, 3 W/35 Hz, 3 W/50 Hz or no laser treatment (Bur-treating as a control). Adper Single Bond 2 was applied to the prepared enamel and the composites were placed and cured. Resin-enamel sticks with an approximate cross-sectional area of 0.8 mm2 were obtained, and microtensile bond strength (µTBS) tests were performed at 24-hour and 12-month of water storage after bonding. The µTBS data were analyzed with two-way ANOVA and Tukey tests (p < 0.05). 24-hour water storage after bonding, the µTBS to laser-irradiated enamel in the 6W/ 20 Hz group was significantly lower than those of bur-treated. However, 3 W/50 Hz showed significantly higher µTBS than those of bur-treated. Two-way ANOVA revealed that 12-month water storage did not influenced µTBS. It may be concluded that, initial bond strength to Er,Cr:YSGG laser irradiated-enamel might be significantly influenced by power and pulse frequency settings. However, resin bonding to laser-irradiated enamel was stable over 12-month water storage regardless of tested laser parameters.