Does surface treatment of demineralized dentin impact on shear bond strength?

Aim: This study investigated the effect of various surface treatments on the bond strength of a universal adhesive to demineralized dentin.

Materials and Methods: Human dentin surfaces of forty-eight carries-free maxillary premolars were prepared and demineralized by acidic solutions. Teeth were randomly distributed into four groups (n=12) getting different surface treatments. Three minutes application of a CPP‑ACP (group 1), Er: YAG laser irradiation (group 2), Er: YAG laser irradiation combined with three minutes application of CPP‑ACP (group 3), no treatment (group 4). Thereafter composite tube (Filtek TM Ultimate, 3M ESPE) bonded to the testing surfaces via universal adhesive; Single Bond Universal and the Shear Bond Strength (SBS) measured. Data were analyzed utilizing ANOVA and Tukey tests (P<0.05).

Results: Only application of CPP-ACP and Er: YAG laser radiation, resulted in the highest and lowest SBS respectively (p<0.001). Bond strength after irradiation of Er: YAG laser combined with three minutes application of CPP‑ACP was a little more than laser alone.

Conclusion: The application of CPP-ACP could increase the SBS of universal adhesives used to demineralized dentin. Laser irradiation application has an adverse effect on SBS.