title: Plasma arc curing of ceramic brackets: an evaluation of shear bond strength and debonding characteristics.
abstract: The aim of this in vitro investigation was to evaluate bond strength and debonding characteristics when a xenon plasma arc curing light is used to bond polycrystalline and monocrystalline ceramic brackets. Brackets were bonded to 240 extracted bovine mandibular incisors with a composite adhesive. Curing intervals of 1, 3, and 6 seconds were chosen for curing with the plasma arc light, and the control group was cured at 10 seconds per bracket with a conventional halogen light. Debonding was performed on a universal testing machine and according to the bracket manufacturers' recommendations. Both the polycrystalline and the monocrystalline brackets consistently debonded at the bracket-adhesive interface, regardless of debonding method, curing interval, or curing light. No enamel fractures were observed after debonding. Bracket fractures were rare and did not affect debonding. Bond strength was significantly higher for the monocrystalline brackets (P <.0001): mean shear bond strength ranged between 9.68 +/- 2.17 MPa (plasma arc curing light, 1 sec curing interval) and 10.73 +/- 3.22 MPa (halogen light, 10 sec curing interval) for the polycrystalline brackets and between 19.85 +/- 2.97 MPa (plasma arc curing light, 1 sec curing interval) and 22.94 +/- 3.20 MPa (plasma arc curing light, 3 sec curing interval) for the monocrystalline brackets. Significant differences were also found for the curing methods used (P =.047). A curing interval of 3 seconds with the plasma arc curing light is recommended for both polycrystalline and monocrystalline ceramic brackets.
authors.affiliation: Department of Orthodontics, College of Dentistry, University of Hamburg, 20246 Hamburg, Germany. klocke@uke.uni-hamburg.de
authors.forename: Arndt
authors.initials: A
authors.lastname: Klocke
authors.forename: Heike M
authors.initials: HM
authors.lastname: Korbmacher
authors.forename: Lothar G
authors.initials: LG
authors.lastname: Huck
authors.forename: Joydeep
authors.initials: J
authors.lastname: Ghosh
authors.forename: Bärbel
authors.initials: B
authors.lastname: Kahl-Nieke
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate; D002417:Cattle; D002516:Ceramics / Q000737:chemistry / Q000528:radiation effects*; D001840:Dental Bonding; D017005:Dental Debonding; D003748:Dental Equipment; D003799:Dental Stress Analysis; D008027:Light; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D019279:Resin Cements; D033081:Shear Strength; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D014978:Xenon
chemical_list: D019279:Resin Cements; C065742:Transbond; D014978:Xenon; D017438:Bisphenol A-Glycidyl Methacrylate