Comparison of Microleakage beneath Orthodontic Brackets Using Two Different Methods of Enamel Preparation

Abstract

Statement of Problem: Decalcification of the enamel in orthodontic patients mainly follows plaque accumulation, but it is promoted by appliance component-ts and the materials used for bonding. Purpose: This study was designed to compare the microleakage beneath meta-llic orthodontics brackets, using two different methods of enamel preparation.Materials and Method: Sixty bovine deciduous lower incisors were collected, and divided into two equal groups. For bonding the stainless steel brackets using Transbond XT as light cured composite, the surface enamel preparation of each group was as follows: Group I: Acid etch+Transbond XT primer and Group II: self-etching primer. After immersion in fuchsin basic 0.5% for 24 hours, each group was randomly divided into two subgroups of 15 samples and placed in acrylic block, in order to have mesiodistal and buccolingual sectioning. The sectioned teeth were evaluated under stereomicroscope and both enamel-adhesive and adhesive-bracket interfaces were scored for the microleakage. Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis to compare the groups. The level of significance was set at p <0.05.Results: No significant differences in the microleakage scores on the gingival and incisal sides were observed in the interfaces between the groups ( p >0.05). Mesiodistal margins of the self-etching group showed significantly lower scores for microleakage in the enamel-adhesive interface in comparison with acid etch group ( p <0.05).Conclusion: With the limitation of this study using the self-etch primers in enamel preparation for bonding of the orthodontic brackets seems acceptable if all the margins of the brackets are cured directly.