title: The influence of accelerating the setting rate by ultrasound or heat on the bond strength of glass ionomers used as orthodontic bracket cements.
abstract: Conventional glass ionomer cements (GICs) may be a viable option for bracket bonding when the major disadvantages of these materials, such as the slow setting reaction and the weak initial bond strength, are solved. The aim of this in vitro study was to investigate the influence of ultrasound and heat application on the setting reaction of GICs, and to determine the tensile force to debond the brackets from the enamel. A conventional fast-setting GIC, Fuji IX Fast, and two resin-modified glass ionomer cements (RMGICs), Fuji Ortho LC and Fuji Plus, were investigated. Three modes of curing were performed (n = 10): (1) according to the manufacturer's prescription, (2) with 60 seconds application of heat, or (3) with 60 seconds application of ultrasound. The tensile force required to debond the brackets was determined as the tension 15 minutes after the start of the bonding procedure. The mode of failure was scored according to the Adhesive Remnant Index (ARI) to establish the relative amount of cement remnants on the enamel surface. Curing with heat and ultrasound shortened the setting reaction and significantly (P < 0.05) increased the bond strength to enamel. The ARI scores showed an increase for all materials after heat and ultrasound compared with the standard curing method, most notably after heat application.
authors.affiliation: Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam, The Netherlands.
authors.forename: T J
authors.initials: TJ
authors.lastname: Algera
authors.forename: C J
authors.initials: CJ
authors.lastname: Kleverlaan
authors.forename: A J
authors.initials: AJ
authors.lastname: de Gee
authors.forename: B
authors.initials: B
authors.lastname: Prahl-Andersen
authors.forename: A J
authors.initials: AJ
authors.lastname: Feilzer
mesh_terms: D000180:Acrylic Resins; D000538:Aluminum Silicates; D000704:Analysis of Variance; D000818:Animals; D001831:Body Temperature; D002417:Cattle; D001840:Dental Bonding / Q000379:methods*; D017005:Dental Debonding; D003782:Dental Pulp; D003799:Dental Stress Analysis; D005899:Glass Ionomer Cements; D006244:Hardness; D006358:Hot Temperature; D008422:Materials Testing; D016910:Orthodontic Brackets; D044367:Phase Transition; D013718:Tensile Strength; D014465:Ultrasonics
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; C439808:Fuji IX GP Fast; C095451:Fuji Ortho LC; C113301:FujiPlus; D005899:Glass Ionomer Cements