Purpose: This study was conducted to investigate the surface effects on dentin following laser etching with an Nd:YAG laser, and to determine the shear bond strengths of composite to untreated and laser-treated dentin. Materials and Methods: Dentin surfaces from freshly extracted permanent molars were subjected to laser treatment with an Nd:YAG laser. The results were analyzed using an SPSS/PC multiple range test. The shear bond strengths of laser-treated dentin/composite and untreated dentin/composite by dentin bonding were also determined. These results were also compared using the SPSS/PC multiple range test. Results: Shear bond strength in laser and acid groups were 6.70 ± 2.86 and 15.24 ± 8.51 MPa, respectively. Bond strength in the laser group was significantly lower than in the other group (p < 0.01). Conclusion: The Nd:YAG dental laser tested produced weaker shear bond strength than conventional acid etching.
Keywords: shear bond, dentin, Nd:YAG laser