title: Effect of Acid Etching, Silane and Thermal Cycling on the Bond Strength of Metallic Brackets to Ceramic.
abstract: The aim of this study was to evaluate the effect of silanes, thermal cycling and acid etching on the shear bond strength (SBS) of metallic brackets to feldspathic ceramic. Feldspathic ceramic cylinders (Groups 1, 2, 5 and 6) were etched for 60 s with 10% hydrofluoric acid and Groups 3, 4, 7 and 8, without acid etching. Two layers of silane Clearfil Ceramic Primer (CCP, Groups 1 to 4) and two layers of RelyX Ceramic Primer (RCP, groups 5 to 8) were applied and dried for 60 s. Brackets were bonded to the cylinders with Transbond XT and light-activated for 40 s with Bluephase G2. All specimens were stored in deionized water at 37 °C for 24 h, and the specimens of groups 1, 3, 5 and 7 were submitted to 7,000 thermal cycles (5 °C/55 °C). After storage, the SBS test was performed at a crosshead speed of 1 mm/min. Data were subjected to three-way ANOVA and Tukey's post hoc test (α=0.05). The adhesive remnant index (ARI) was evaluated at 8x magnification. The SBS of CCP was significantly greater than of RCP (p<0.05), with or without thermal cycling. Thermal cycling significantly reduced the SBS (p<0.05). The groups submitted to acid etching showed significantly higher SBS than those without acid etching (p<0.05). In conclusion, thermal cycling reduced SBS for all groups. The best ceramic surface treatment for bracket bonding was achieved by acid etching and CCP silane. The ARI results showed predominance of score 0 for all groups.
authors.affiliation: Department of Orthodontics, Graduate Program in Orthodontics, UNIARARAS - Universidade de Araras, Araras, SP, Brazil.
authors.forename: Natália Regina Santos de
authors.initials: NR
authors.lastname: Matos
authors.affiliation: Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP, Universidade Estadual de Campinas, Piracicaba, SP, Brazil.
authors.forename: Ana Rosa
authors.initials: AR
authors.lastname: Costa
authors.affiliation: Department of Orthodontics, Graduate Program in Orthodontics, UNIARARAS - Universidade de Araras, Araras, SP, Brazil.
authors.forename: Heloísa Cristina
authors.initials: HC
authors.lastname: Valdrighi
authors.affiliation: Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP, Universidade Estadual de Campinas, Piracicaba, SP, Brazil.
authors.forename: Américo Bortolazzo
authors.initials: AB
authors.lastname: Correr
authors.affiliation: Department of Orthodontics, Graduate Program in Orthodontics, UNIARARAS - Universidade de Araras, Araras, SP, Brazil.
authors.forename: Silvia Amélia
authors.initials: SA
authors.lastname: Vedovello
authors.affiliation: Department of Orthodontics, Graduate Program in Orthodontics, UNIARARAS - Universidade de Araras, Araras, SP, Brazil.
authors.forename: Milton
authors.initials: M
authors.lastname: Santamaria
authors.affiliation: Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP, Universidade Estadual de Campinas, Piracicaba, SP, Brazil.
authors.forename: Lourenço
authors.initials: L
authors.lastname: Correr-Sobrinho
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D002516:Ceramics; D003799:Dental Stress Analysis; D008670:Metals; D016910:Orthodontic Brackets
chemical_list: D008670:Metals