title: Effects of thermocycling and light source on the bond strength of metallic brackets to bovine teeth.
abstract: This study evaluated the effects of thermocycling and different light sources on the bond strength of metallic brackets to bovine tooth enamel using an adhesive resin. Bovine teeth were etched with 35% phosphoric acid gel for 20 s. After application of primer, metallic brackets were bonded to the buccal surface using Transbond XT, forming 8 groups (n = 20), depending on the light source used for photoactivation (AccuCure 3000 argon laser--20 s, Apollo 95E plasma arc--12 s, UltraLume 5 LED--40 s and XL2500 halogen light--40 s) and experimental conditions without (Groups 1 to 4) or with thermocycling (Groups 5 to 8). Shear bond testing was carried out after 24 h of distilled water storage (Groups 1 to 4) or storage and thermocycling in distilled water (groups 5 to 8; 1,500 cycles--5°/55 °C). Data were subjected to two-way ANOVA and Tukey's test (α = 0.05). The Adhesive Remnant Index (ARI) was evaluated at ×8 magnification. No significant differences (p>0.05) in bond strength were found when the conditions without and with thermocycling were compared for any of the light sources. No significant differences (p>0.05) in bond strength were found among the light sources, irrespective of performing or not thermocycling. There was a predominance of ARI scores 1 in all groups. In conclusion, light sources and thermocycling had no influence on the bond strength of brackets to bovine enamel.
authors.affiliation: Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil. anarosacosta_1@fop.unicamp.br
authors.forename: Ana Rosa
authors.initials: AR
authors.lastname: Costa
authors.forename: Américo Bortolazzo
authors.initials: AB
authors.lastname: Correr
authors.forename: Regina Maria
authors.initials: RM
authors.lastname: Puppin-Rontani
authors.forename: Silvia Amélia Scudeler
authors.initials: SA
authors.lastname: Vedovello
authors.forename: Heloísa Cristina
authors.initials: HC
authors.lastname: Valdrighi
authors.forename: Lourenço
authors.initials: L
authors.lastname: Correr-Sobrinho
authors.forename: Mário
authors.initials: M
authors.lastname: Vedovello Filho
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D000818:Animals; D002417:Cattle; D055117:Curing Lights, Dental / Q000145:classification*; D003722:Dental Alloys / Q000737:chemistry*; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D003799:Dental Stress Analysis / Q000295:instrumentation; D008027:Light; D008422:Materials Testing; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003722:Dental Alloys; D010756:Phosphoric Acids; D019279:Resin Cements; C477790:Transbond XT; D014867:Water; D013193:Stainless Steel; C030242:phosphoric acid