Bond strength and debonding characteristics of a new ceramic bracket.
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.
Liu
Jia-Kuang
JK
Department of Dentistry, National Cheng Kung University, 138 Sheng-Li Road, Tainan 204, Taiwan, ROC. jkliu@mail.ncku.edu.tw
Chung
Ching-Hung
CH
Chang
Chuan-Yang
CY
Shieh
Dar-Bin
DB
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
C418867:Enlight; D019279:Resin Cements; C477790:Transbond XT; D000537:Aluminum Oxide