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

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 3.5W (group 3) and at 4W (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.