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

Statement of problem: decalcification of the enamel in orthodontic patientsmainly follows plaque accumulation, but it is promoted by appliance componenttsand the materials used for bonding.purpose: this study was designed to compare the microleakage beneath metallicorthodontics 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 usingtransbond xt as light cured composite, the surface enamel preparation of eachgroup 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, eachgroup was randomly divided into two subgroups of 15 samples and placed inacrylic block, in order to have mesiodistal and buccolingual sectioning. thesectioned teeth were evaluated under stereomicroscope and both enameladhesiveand adhesive-bracket interfaces were scored for the microleakage.kruskal-wallis and mann-whitney u tests were used for statistical analysis tocompare the groups. the level of significance was set at p <0.05.results: no significant differences in the microleakage scores on the gingivaland incisal sides were observed in the interfaces between the groups ( p >0.05).mesiodistal margins of the self-etching group showed significantly lower scoresfor microleakage in the enamel-adhesive interface in comparison with acid etchgroup ( p <0.05).conclusion: with the limitation of this study using the self-etch primers inenamel preparation for bonding of the orthodontic brackets seems acceptable ifall the margins of the brackets are cured directly.