Optimum criteria of using Er:YAG laser in roughening PICN surface: a pilot in-vitro study.

Background: The purpose of this study was to evaluate the efficiency of Er:YAG laser irritation on the roughness (Ra) value of Enamic surface (PICN) at different energy settings, and determine the optimal energy setting for a successful pre-treatment.

Methods: The study included 5 experimental groups (N.=8), including group A, untreated group (control); surface roughness of this group was measured with surface roughness tester (profilometer), then a total number of 32 PICN discs were randomly divided into 4 groups according to the treatment conducted, group B, hydrofluoric acid-etched (HF); group C, D, E in order (150, 250, 400 mJ Er:YAG laser-irritated); and roughness was measured by the same method applied to control group. Data were collected in microns (μm) and analyzed using one-way ANOVA and post hoc comparison tests (a=0.05).

Results: All of the treatments improved surface roughness because a significant difference was observed between group A and all other groups P<0.05, the highest mean roughness value was in group B and E, followed by group C and D. The post hoc test showed there was no statistical difference found between groups B and E.

Conclusions: In terms of surface roughening, a conclusion can be made that irritating PICN inner surface with 400w Er:YAG can be an alternative pretreatment method to hydrofluoric acid.