The Effect of Enamel Sandblasting on Enhancing Bond Strength of Orthodontic Brackets: A Systematic Review and Meta-analysis

Purpose: To critically appraise the evidence regarding the effect of enamel sandblasting on the bond strength of orthodontic brackets on either the labial or lingual tooth surface. Materials and Methods: An electronic database search of published and unpublished literature was performed. Search terms included sandblasting, enamel abrasion, tooth surface, bond strength, bond failure, and adhesive remnant; data were extracted in standardized piloted forms. Risk of bias was assessed using the Cochrane risk of bias tool, adapted for in vitro studies where necessary. Results: Of the 81 articles initially retrieved, 13 were eligible for inclusion in the systematic review. All of the latter were in vitro studies with unclear risk of bias primarily due to unclear reporting of blinding of outcome assessors. Eight studies assessed the combined effect of enamel sandblasting and etching, while only five evaluated the isolated effect of sandblasting on the buccal enamel surface. In view of the apparently heterogeneous study settings, intervention protocols, specimen preparation and storage sequences, only two studies were deemed eligible for quantitative synthesis. Random effects meta-analysis revealed no evidence to support sandblasting prior to etching over etching alone with regard to shear bond strength of orthodontic brackets bonded in vitro to lingual enamel surfaces of extracted premolars (standardized mean difference: 0.36; 95% CI: -0.21, 0.94; p = 0.22). Conclusions: The findings of the present study cannot support lingual enamel sandblasting prior to etching for augmentation of the bond strength of orthodontic brackets. Keywords: sandblasting, orthodontic bonding, shear bond strength, lingual orthodontics, brackets