Effect of Er: YAG Laser Enamel-etching and Sandblasting on the Bond Strength of Fixed Lingual Retainers

This study aims to compare the shear bond strength (SBS) of different combinations of retainer wires and enamel preparation methods.

A total of 180 extracted mandibular bovine incisors were randomly divided into nine groups of 20 paired teeth each. Three techniques were employed to prepare the enamel: acid etches only, Er:YAG laser before acid etch, and sandblast before acid etch. The retainer wires, including Bond-A-Braid, GAC Wildcat Twistflex Wire, and TruForce coaxial wire, were bonded with the adhesive Transbond LR and SBS values were measured. The two-way ANOVA test was used to evaluate the effect of the conditioning method in combination with the retainer wire type and the interaction of two variables. Pairwise comparisons were done using the Tukey post hoc test. A value of P≤0.05 was considered to be significant for all statistical tests.

The highest shear bond strength value was found for sandblasted surface bonded with Bond-A-Braid wire. The combination of acid-etched enamel/GAC Wildcat Twistflex wire revealed the lowest value of the SBS. Statistically significant differences did not exist for the Adhesive Remnant Index (ARI) scores among the study groups.

Sandblasting and laser irradiation before the acid etching significantly increased the SBS. Differences in the SBS values of different wires were insignificant.