title: Bond strength and debonding characteristics of a new ceramic bracket.
abstract: BACKGROUND
  The purposes of this study were to evaluate the shear bond strength of a new collapsible monocrystalline bracket (Inspire, Ormco, Orange, Calif) and compare it with another collapsible ceramic bracket (Clarity, 3M Unitek, Monrovia, Calif) and a metal bracket; to examine the modes of failure after shear bond strength testing; and to observe the tooth surface after debonding the ceramic brackets with pliers.
  
  
  METHODS
  One hundred extracted human premolars were selected for bonding. Three types of brackets and 2 orthodontic adhesives (Transbond XT, 3M Unitek; and Enlight, Ormco) were used. After bonding, all samples were placed in a distilled water bath at 37 degrees C for 24 hours. The shear bond strength of 60 samples was measured, and the remaining 40 samples with ceramic brackets were debonded with pliers.
  
  
  RESULTS
  No statistically significant differences in bond strengths among the different combinations of brackets and adhesives were found (P > .05). The mode of failure after debonding by either shear bond strength testing or with pliers was predominantly at the bracket/adhesive interface in all groups. Enamel and bracket fractures were noted in 2 and 5 of 20 samples for Inspire, and 1 and 0 of 20 samples for Clarity after debonding with pliers.
  
  
  CONCLUSIONS
  Bond strength and mode of failure of Inspire were similar to those of Clarity, but the risk of bracket fracture after debonding for Inspire was greater.
authors.affiliation: Department of Dentistry, National Cheng Kung University, 138 Sheng-Li Road, Tainan 204, Taiwan, ROC. jkliu@mail.ncku.edu.tw
authors.forename: Jia-Kuang
authors.initials: JK
authors.lastname: Liu
authors.forename: Ching-Hung
authors.initials: CH
authors.lastname: Chung
authors.forename: Chuan-Yang
authors.initials: CY
authors.lastname: Chang
authors.forename: Dar-Bin
authors.initials: DB
authors.lastname: Shieh
mesh_terms: D000537:Aluminum Oxide; D000704:Analysis of Variance; D001641:Bicuspid; D002516:Ceramics; D001840:Dental Bonding; D017005:Dental Debonding; D003799:Dental Stress Analysis; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D016910:Orthodontic Brackets; D019279:Resin Cements; D033081:Shear Strength; D018709:Statistics, Nonparametric
chemical_list: C418867:Enlight; D019279:Resin Cements; C477790:Transbond XT; D000537:Aluminum Oxide