title: Bond strength of aged composites found in brackets placed by an indirect technique.
abstract: The "Thomas" indirect technique for bracket attachment produces an interface not present in direct techniques, that is, an aged composite-sealant interface. Our primary goal was to determine if a weakened interface was produced by a modified (sealant was mixed prior to placement of brackets) Thomas indirect technique when the composite was aged for 7 days. The enamel-bracket system was investigated in vitro by comparison of shear bond strengths for metal and ceramic brackets bonded to bovine teeth by a direct and indirect method. Nearly all specimens failed at the bracket-composite interface and, subsequently, no difference was found between specimens placed by direct or indirect methods. No evidence was found to suggest that an aged composite would predispose the enamel-bracket system to fail at the sealant-composite interface. The ceramic brackets used in this investigation had lower bond strengths then metal ones, but the breaking loads were similar.
authors.affiliation: Dept. of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor 48109-1078.
authors.forename: J Y
authors.initials: JY
authors.lastname: Shiau
authors.forename: S T
authors.initials: ST
authors.lastname: Rasmussen
authors.forename: A E
authors.initials: AE
authors.lastname: Phelps
authors.forename: D H
authors.initials: DH
authors.lastname: Enlow
authors.forename: G R
authors.initials: GR
authors.lastname: Wolf
mesh_terms: D000269:Adhesives / Q000737:chemistry; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002417:Cattle; D002516:Ceramics / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods; D003743:Dental Enamel; D003799:Dental Stress Analysis; D008422:Materials Testing; D016910:Orthodontic Brackets; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D000269:Adhesives; D003188:Composite Resins; D003722:Dental Alloys; D017438:Bisphenol A-Glycidyl Methacrylate