title: Influence of Sealer and Light-Curing Units on Push-Out Bond Strength Of Composite Resin to Weakened Roots.
abstract: The aim of this study was to assess the influence of sealer and light-curing unit on regional bond strength of resin composite to the weakened roots. Ninety roots of incisors were experimentally weakened, subjected to biomechanical preparation and filled with either Endofill, AH Plus or MTA Fillapex The roots were desobturated e reinforced with resin composite and fiber post light-activated with one of the light sources: halogen at 600 mW/ cm2 (QTH-600), LED at 800 mW/ cm2 (LED-800) and LED at 1500 mW/ cm2 (LED-1500). The roots were sectioned in slices from cervical, middle and apical root-reinforcement regions and analyzed by push out test, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Bond strength data were analyzed using three-way ANOVA and Tukey´s test (α=0.05). Specimens filled with AH Plus had higher bond strength, followed by MTA Fillapex and Endofill (p<0.05). For light-curing unit, LED-1500 presented superior bond strength than LED-800, which was higher than QTH-600 (p<0.05). The cervical region had the greatest mean values (p<0.05) while apical part showed the lowest bond strength (p<0.05). CLMS revealed remaining filling material in the dentinal tubules for all groups. The eugenol-containing sealer (Endofill) compromised the push-out bond strength of composite resin to the root dentin. Bond strength was favored in the cervical region, and when LED-1500 was used.
authors.affiliation: Department of Dentistry, Positivo University, Curitiba, PR, Brazil.
authors.forename: Adriana Corrêa de
authors.initials: AC
authors.lastname: Lima
authors.affiliation: Department of Dentistry, Positivo University, Curitiba, PR, Brazil.
authors.forename: Fuad Jacob
authors.initials: FJ
authors.lastname: Rached-Junior
authors.affiliation: Department of Dentistry, Positivo University, Curitiba, PR, Brazil.
authors.forename: Natália Spadini de
authors.initials: NS
authors.lastname: Faria
authors.affiliation: Department of Dentistry, Positivo University, Curitiba, PR, Brazil.
authors.forename: Danielle Cristine
authors.initials: DC
authors.lastname: Messias
authors.affiliation: Department of Dentistry, Positivo University, Curitiba, PR, Brazil.
authors.forename: Carolina de Andrade Lima
authors.initials: Cde A
authors.lastname: Chaves
authors.affiliation: Department of Dentistry, Positivo University, Curitiba, PR, Brazil.
authors.forename: Jessica Vavassori de
authors.initials: JV
authors.lastname: Freitas
authors.affiliation: Department of Dentistry, Positivo University, Curitiba, PR, Brazil.
authors.forename: Flares
authors.initials: F
authors.lastname: Baratto-Filho
authors.affiliation: Department of Dentistry, Positivo University, Curitiba, PR, Brazil.
authors.forename: Yara Teresinha Corrêa
authors.initials: YT
authors.lastname: Silva-Sousa
mesh_terms: D003188:Composite Resins; D006801:Humans; D008422:Materials Testing; D014092:Tooth Root
chemical_list: D003188:Composite Resins