title: Influence of the LED curing source and selective enamel etching on dentin bond strength of self-etch adhesives in class I composite restorations.
abstract: The aim of this study was to evaluate the influence of the LED curing unit and selective enamel etching on dentin microtensile bond strength (μTBS) for self-etch adhesives in class I composite restorations. On 96 human molars, box-shaped class I cavities were made maintaining enamel margins. Self-etch adhesives (Clearfil SE - CSE and Clearfil S(3) - S3) were used to bond a microhybrid composite. Before adhesive application, half of the teeth were enamel acid-etched and the other half was not. Adhesives and composites were cured with the following light curing units (LCUs): one polywave (UltraLume 5 - UL) and two single-peak (FlashLite 1401 - FL and Radii Cal - RD) LEDs. The specimens were then submitted to thermomechanical aging and longitudinally sectioned to obtain bonded sticks (0.9 mm(2)) to be tested in tension at 0.5 mm/min. The failure mode was then recorded. The μTBS data were submitted to a three-way ANOVA and Tukey's (α = 0.05). For S3, the selective enamel-etching provided lower μTBS values (20.7 ± 2.7) compared to the non-etched specimens (26.7 ± 2.2). UL yielded higher μTBS values (24.1 ± 3.2) in comparison to the photoactivation approach with FL (18.8 ±3.9) and RD (19.9 ±1.8) for CSE. The two-step CSE was not influenced by the enamel etching (p ≥ 0.05). Enamel acid etching in class I composite restorations affects the dentin μTBS of the one-step self-etch adhesive Clearfil S(3), with no alterations for Clearfil SE bond strength. The polywave LED promoted better bond strength for the two-step adhesive compared to the single-peak ones.
authors: Department of Restorative Dentistry, Dental Materials Area, Piracicaba Dental School, University of Campinas, Areião, SP, Brazil. edujcsj@gmail.com
authors: Eduardo José
authors: EJ
authors: Souza-Junior
authors: Cíntia Tereza Pimenta
authors: CT
authors: Araújo
authors: Lúcia Trazzi
authors: LT
authors: Prieto
authors: Luís Alexandre Maffei Sartini
authors: LA
authors: Paulillo
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D055117:Curing Lights, Dental; D003793:Dental Restoration, Permanent / Q000145:classification / Q000379:methods; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D055115:Light-Curing of Dental Adhesives / Q000379:methods*; D008689:Methacrylates; D008963:Molar; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements