In Vitro Evaluation of Microleakage Around Orthodontic Brackets Using Laser Etching and Acid Etching Methods

Objective: path of microleakage between the enamel and adhesive potentially al-lows microbial ingress that may consequently cause enamel decalcification. the aim of this study was to compare microleakage of brackets bonded either by laser or acid etching techniques.material and methods: the specimens were 33 extracted premolars that were divided into three groups as the acid etching group (group 1), laser etching with er:yag at 100 mj and 15 hz for 15s (group 2), and laser etching with er:yag at 140 mj and 15 hz for 15s (group 3). after photo polymerization, the teeth were subjected to 500 thermal cycles. then the specimens were sealed with nail var-nish, stained with 2% methylen blue for 24hs, sectioned, and examined under a stereomicroscope. they were scored for marginal microleakage that occurred be-tween the adhesive-enamel and bracket-adhesive interfaces from the occlusal and gingival margins. data were analyzed with the kruskal- wallis test.results: for the adhesive-enamel and bracket-adhesive surfaces, significant dif-ferences were not observed between the three groups.conclusion: according to this study, the er:yag laser with 1.5 and 2.1 watt set-tings may be used as an adjunctive for preparing the surface for orthodontic bracket bonding.