Argon laser vs conventional visible light-cured orthodontic bracket bonding: An in-vivo and in-vitro study

Introduction: Many advantages of argon lasers have been reported, including high-speed orthodontic adhesive curing and less enamel demineralization. The purpose of this study was to compare bond strengths after curing with the argon laser (10 seconds) and the conventional curing light (40 seconds) in vivo and in vitro. Methods: Four premolars from each of 23 volunteers were randomly assigned to either the argon laser group or the conventional light group for the in-vivo study. Shear bond strengths were measured after 14 days with custom-designed debonding pliers. In-vitro bond strengths were measured by using 4 premolars from each of 25 volunteers. Shear bond strength was measured after 14 days of thermocycling with the same protocol as the in-vivo study. Adhesive remnant index scores (ARI) were determined. Results: No significant differences were found in bond strengths according to curing method, dental arch, or sex. In-vivo results were significantly lower (P < .05) than in-vitro results. A significant (P < .05) difference in ARI scores between the curing methods was determined; no significant correlation between mean bond strengths and ARI scores was determined. Conclusions: Bond strength for argon laser curing is comparable to conventional light curing and is sufficient for clinical applications. Although the argon laser left more adhesive on the tooth surfaces on debonding, there was no increase in enamel surface fractures.