Nd:YAG Laser Influence on Bond Strength of Adhesive Resins to Dentin

Abstract

The aim of this study was to evaluate the influence of Nd:YAG laser on microtensile bond strength (μTBS) of different adhesive materials to human dentin. Eighteen human third molars were divided into 6 groups. Group 1 – adhesive system, Adper Single Bond 2 (SB); Group 2 – adhesive system, Clearfil SE Bond (CSEB); Group 3 – self-adhesive resin luting cement, RelyX Unicem; Group 4 – irradiation with Nd:YAG laser and application of SB; Group 5 – irradiation with Nd:YAG laser and application of CSEB; Group 6 – irradiation with Nd:YAG laser and application of RelyX Unicem. A composite resin block was built on the dentin surfaces, and sticks with a cross-sectional area of ~0.80 mm2 were obtained. Twenty specimens per group were selected and subjected to μTBS testing in a universal testing machine. According to the analysis of variance and Tukey test (α = 0.05), the highest μTBS mean was obtained with CSEB (41.75 MPa) without laser irradiation, but this value was not statistically different from CSEB with laser irradiation (33.42 MPa). Mean μTBS of SB without (32.15 MPa) and with (35.38 MPa) laser irradiation did not differ statistically. The lowest μTBS values were obtained for RelyX Unicem, and the group without laser irradiation showed statistically higher values (14.50 MPa) than those found with laser irradiation (7.53 MPa). Nd:YAG laser did not significantly reduce bond strength of the adhesive systems under study, except for the self-adhesive resin luting cement.