title: Failure mode analysis of ceramic brackets bonded to enamel.
abstract: The purpose of this study was to evaluate in vitro the failure pattern of ceramic brackets bonded to enamel with a light-cured orthodontic adhesive. Five types of ceramic brackets and 125 incisors were used in the study. The brackets were bonded onto enamel with a light-cured orthodontic adhesive. After 1 week storage and thermal cycling, the samples were debonded by one operator according to the individual technique for each bracket group proposed by each manufacturer. The fracture surfaces were examined under a stereomicroscope to reveal the type of failures. The effect of the debonding procedure on enamel structure was significantly affected by the various bonding mechanisms of the bracket bases. Cohesive enamel fractures were detected from brackets that provided a bonding mechanism of micromechanical retention and chemical adhesion. The brackets that combined mechanical retention and chemical adhesion, presented both cohesive resin fractures and fractures located at the bracket resin or the resin enamel interface. The higher frequency of cohesive bracket fractures was obtained from a monocrystalline bracket.
authors.affiliation: Research Center for Biomaterials, Athens, Greece.
authors.forename: T
authors.initials: T
authors.lastname: Eliades
authors.forename: A D
authors.initials: AD
authors.lastname: Viazis
authors.forename: M
authors.initials: M
authors.lastname: Lekka
mesh_terms: D002516:Ceramics; D016009:Chi-Square Distribution; D001840:Dental Bonding; D017005:Dental Debonding; D003743:Dental Enamel / Q000293:injuries; D004868:Equipment Failure; D006801:Humans; D016910:Orthodontic Brackets / Q000009:adverse effects