Shear bond strength of different adhesives to Er:YAG laser-prepared dentin

The aim of this study was to examine the influence of Er:YAG laser on the shear bond strength of three different adhesives to lased dentin.

Seventy specimens obtained from 35 extracted human molars were embedded in polyester resin and ground with silicon carbide papers. The samples were divided into seven groups. 1. Er:YAG laser (Key Laser 3, KaVo) + Clearfil Protect Bond (Kuraray); 2. Er:YAG laser + Clearfil tri-S Bond (Kuraray); 3. Er:YAG laser + 37% H3PO4 + Single Bond 2 (3M-ESPE); 4. Er:YAG laser + Single Bond 2; 5. conventional method + Clearfil Protect Bond; 6. conventional method + Clearfil tri-S Bond; 7. conventional method + 37% H3PO4 + Single Bond 2. The samples were subjected to shear bond testing 24 h after bonding. Statistical analyses were carried out by two-way ANOVA, t-test, one-way ANOVA, post-hoc Tukey's and Dunnett C test (p = 0.05).

Only the Er:YAG laser + Clearfil tri-S Bond group demonstrated significantly higher bond strengths vs conventionally prepared specimens (p < 0.05). There were no significant differences between the shear bond strengths of Single Bond 2 adhesive applied to laser- vs bur-treated specimens (p > 0.05). In laser prepared samples, Clearfil Protect Bond showed the highest scores (p < 0.05), whereas in conventionally prepared groups, no statistical differences were observed between Clearfil Protect Bond and Clearfil tri-S Bond (p > 0.05).

Er:YAG laser irradiation did not adversely affect the shear bond strength of Single Bond 2 and Clearfil Protect Bond to dentin, whereas it increased the shear bond strength values of Clearfil tri-S Bond.