The Efficacy of Er,Cr:YSGG Laser in Reconditioning of Metallic Orthodontic Brackets

Abstract

Objective: This study aimed to evaluate the efficiency of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in removing adhesive from bracket bases, and its influence on shear bond strength (SBS) of orthodontic brackets, compared to several other recycling methods. Background data: Reconditioning the dislodged attachments is frequently required in orthodontic practice to reduce treatment costs. Materials and methods: Seventy-five premolar teeth were selected and divided into five groups. In groups 1 to 4, brackets recycled with different methods were bonded on the tooth surface, whereas in group 5, new brackets were used. The recycling methods were: silicon carbide stone grinding (group 1), aluminum oxide sandblasting (group 2), and Er,Cr:YSGG laser operated at 3.5 W (group 3) and at 4 W (group 4). The quantitative amount of remaining adhesive on the bracket base was determined after recycling using stereomicroscopic images, and the SBS values were measured. Results: The percentage of adhesive remnants was significantly lower in brackets cleaned with aluminum oxide sandblasting, and significantly higher in those grinded by silicon carbide stone (p<0.05). Brackets cleaned with silicon carbide stone produced the lowest, and those prepared by aluminum oxide blasting or Er,Cr:YSGG laser produced the highest SBS among the groups (p<0.05). There was a significant correlation between changes in percentage of remaining adhesive on the base after recycling with changes in SBS (Pearson r=−0.41, p<0.0001). Conclusions: Under the study conditions, both aluminum oxide blasting and Er,Cr:YSGG laser were efficient in removing adhesive from bracket bases, and resulted in significantly higher bond strength than for new brackets.