title: Effect of irradiation mode and filling technique on resin/dentin bonding strength in Class I cavities.
abstract: Factors such as light-curing mode, filling technique and cavity configuration may affect the bonding strength to dentin. This study evaluated the effect of irradiation mode and filling technique on resin/dentin bonding strength on the buccal wall of Class I cavities in human teeth. Occlusal enamel was removed to expose a flat dentin surface. Occlusal cavities (4 x 3 x 3 mm) were prepared in dentin. The adhesive Single Bond was applied according to the manufacturer's instructions and TPH Spectrum composite resin was placed using the following: oblique incremental, horizontal incremental or bulk filling techniques. The composite resin was light-cured either by continuous (600 mW/cm2 for 40 s) or Soft-Start (250 mW/cm2 for 10 s + 600 mW/cm2 for 30 s) modes. Specimens of the control group were obtained by bonding the material to the flat exposed buccal wall of the cavity (C-factor = 1). The teeth were stored in water at 37 degrees C for 24 h and prepared for microtensile testing. Bonded beams of approximately 0.8 mm2 were obtained from the buccal wall and tested with a tension of 0.5 mm/min. Results were analyzed by two-way ANOVA, Tukey's test and Dunnett's test (alpha = 0.05). Incremental placement techniques with both irradiation modes produced higher bonding strength values than the bulk technique (p < 0.05). Bonding strength tested in the cavities had lower values than those obtained in flat dentin surfaces (control group) (p < 0.05), except for incremental fillings using stepped irradiation. Bonding strength to the cavity walls depends on the filling technique and on the irradiation mode of composite resins.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Piracicaba, State University of Campinas.
authors.forename: Alex José Souza
authors.initials: AJ
authors.lastname: dos Santos
authors.forename: Marcelo
authors.initials: M
authors.lastname: Giannini
authors.forename: Luis Alexandre Maffei Sartini
authors.initials: LA
authors.lastname: Paulillo
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Lovadino
authors.forename: Ricardo Marins
authors.initials: RM
authors.lastname: de Carvalho
mesh_terms: D000704:Analysis of Variance; D001840:Dental Bonding / Q000379:methods*; D003737:Dental Cavity Preparation; D003793:Dental Restoration, Permanent / Q000379:methods*; D003804:Dentin; D006801:Humans; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: D019279:Resin Cements