title: Debonding orthodontic ceramic brackets by ultrasonic instrumentation.
abstract: Breakage of ceramic brackets because of brittleness may cause such problems as aspiration of fragments and injury by flying debris. Portions remaining on the tooth must be laboriously ground off with a handpiece. This study investigated a potential method of lowering the force required to remove ceramic brackets, i.e., use of an ultrasonic chisel. Ceramic brackets were bonded to extracted incisors and canines. The degree of cure of a light-activated cement was systematically varied with different exposure times to a curing light. The brackets were sheared from the teeth with a universal testing machine and a chisel tip on a Cavitron. The ultrasonic chisel markedly reduced the force required to debond the brackets; however, the time of application averaged 16.6 seconds. Reducing the degree of cure of the cement had only a slight effect on the time required and the forces generated. This method of debonding is not recommended without further development.
authors.affiliation: Department of Operative Dentistry, University of Iowa, Iowa City, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Boyer
authors.forename: G
authors.initials: G
authors.lastname: Engelhardt
authors.forename: S E
authors.initials: SE
authors.lastname: Bishara
mesh_terms: D002516:Ceramics; D003188:Composite Resins / Q000737:chemistry; D003481:Cuspid; D003738:Dental Cements / Q000737:chemistry; D017005:Dental Debonding / Q000295:instrumentation*; D003743:Dental Enamel / Q000648:ultrastructure; D003799:Dental Stress Analysis / Q000295:instrumentation; D004868:Equipment Failure; D006801:Humans; D007180:Incisor; D016910:Orthodontic Brackets; D019279:Resin Cements; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D019279:Resin Cements; C047484:heliosit