title: Bond strength of orthodontic light-cured resin-modified glass ionomer cement.
abstract: The purpose of this study was to compare the bond strengths and debonded interfaces achieved with light-cured resin-modified glass ionomer cement (RMGIC) and conventional light-cured composite resin. In addition, the effects of acid etching and water contamination were examined. One hundred human premolars were randomly divided into five equal groups. The mini Dyna-lock upper premolar bracket was selected for testing. The first four groups were treated with light-cured RMGIC with or without 15 per cent phosphoric acid-etching treatment and with or without water contamination preceding bracket bonding. The control samples were treated with the conventional light-cured Transbond composite resin under acid etching and without water contamination. Subsequently, the brackets were debonded by tensile force using an Instron machine. The modified adhesive remnant index (ARI) scores were assigned to the bracket base of the debonded interfaces using a scanning electron microscope. The bond strength and modified ARI scores were determined and analysed statistically by one-way analysis of variance and chi-square test. Under all four conditions, the bond strength of the light-cure RMGIC was equal to or higher than that of the conventional composite resin. The highest bond strength was achieved when using RMGIC with acid etching but without water contamination. The modified ARI scores were 2 for Fuji Ortho LC and 3 for Transbond. No enamel detachment was found in any group. Fifteen per cent phosphoric acid etching without moistening the enamel of Fuji Ortho LC provided the more favourable bond strength. Enamel surfaces, with or without water contamination and with or without acid etching, had the same or a greater bond strength than Transbond.
authors.affiliation: School of Oral Hygiene, School of Dentistry, College of Oral Medicine, Taipei Medical University, Taiwan.
authors.forename: Hsiang Yu
authors.initials: HY
authors.lastname: Cheng
authors.forename: Chien Hsiu
authors.initials: CH
authors.lastname: Chen
authors.forename: Chuan Li
authors.initials: CL
authors.lastname: Li
authors.forename: Hung Huey
authors.initials: HH
authors.lastname: Tsai
authors.forename: Ta Hsiung
authors.initials: TH
authors.lastname: Chou
authors.forename: Wei Nan
authors.initials: WN
authors.lastname: Wang
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D000293:Adolescent; D000538:Aluminum Silicates / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002648:Child; D003188:Composite Resins / Q000737:chemistry; D003743:Dental Enamel / Q000648:ultrastructure; D045662:Dental Etching / Q000379:methods; D003799:Dental Stress Analysis / Q000295:instrumentation; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D003188:Composite Resins; C095451:Fuji Ortho LC; D005899:Glass Ionomer Cements; D010756:Phosphoric Acids; D019279:Resin Cements; D017640:Silicates; D014867:Water; C065742:Transbond; D017438:Bisphenol A-Glycidyl Methacrylate; C030242:phosphoric acid; C005144:pumice