Bond strength and debonding characteristics of a new ceramic bracket

• Published in: American journal of orthodontics and dentofacial orthopedics Vol. 128; no. 6; pp. 761 - 765
• Main Authors: Liu, Jia-Kuang, Chung, Ching-Hung, Chang, Chuan-Yang, Shieh, Dar-Bin
• Format: Journal Article
• Language: English
• Published: United States Mosby, Inc 01.12.2005
• Subjects: Aluminum Oxide; Analysis of Variance; Bicuspid; Ceramics; Dental Bonding; Dental Debonding; Dental Stress Analysis; Dentistry; Equipment Design; Humans; Materials Testing; Orthodontic Brackets; Resin Cements; Shear Strength; Statistics, Nonparametric
• ISSN: 0889-5406; 1097-6752
• DOI: 10.1016/j.ajodo.2004.03.041

Introduction: 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°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.