title: 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
  Reconditioning the dislodged attachments is frequently required in orthodontic practice to reduce treatment costs.
  
  
  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.
authors: Dental Materials Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. AhrariF@mums.ac.ir
authors: Farzaneh
authors: F
authors: Ahrari
authors: Mohammad
authors: M
authors: Basafa
authors: Reza
authors: R
authors: Fekrazad
authors: Mohammad
authors: M
authors: Mokarram
authors: Majid
authors: M
authors: Akbari
mesh_terms: D001840:Dental Bonding; D003738:Dental Cements; D017743:Equipment Reuse; D006801:Humans; D053844:Lasers, Solid-State; D016910:Orthodontic Brackets; D033081:Shear Strength; D013193:Stainless Steel
chemical_list: D003738:Dental Cements; D013193:Stainless Steel