title: Canal preparation and filling techniques do not influence the fracture resistance of extensively damaged teeth.
abstract: The purpose of this study was to assess the fracture resistance of extensively damaged teeth after two root canal preparation techniques (hand and rotary files) and after two filling techniques (active and passive compaction). Sixty-eight maxillary canines roots with an apical diameter equal to that of a #25 K-file were embedded in acrylic resin and the periodontal ligament was simulated by using a polyether impression material. The roots were randomly distributed into four groups (n=17): hand preparation and active compaction (HA), hand preparation and passive compaction (HP), rotary preparation and active compaction (RA), and rotary preparation and passive compaction (RP). All roots were restored with glass fiber post and metallic crown. The specimens were mechanically cycled (500,000 cycles, 45 °, 37 °C, 133 N, 2 Hz) and then subjected to a fracture resistanhe fracture resistance values ranged between 621.15 N (HP) and 785.71 N (HA). However, the Kruskal-Wallis test did not reveal differences in the fracture ce test. A single blinded examiner analyzed the external root surface and classified the failure pattern as favorable or unfavorable. Tresistance values among the four groups (p =0.247). Under the tested conditions, root canal preparation and filling techniques had no influence on the fracture resistance of extensively damaged teeth restored with fiber post and metallic crown.
authors.affiliation: Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Manuela Favarin
authors.initials: MF
authors.lastname: Santini
authors.affiliation: Department of Dental Materials and Prosthodontics, School of Dentistry of São José dos Campos, Univ Estadual Paulista, São José dos Campos, SP, Brazil.
authors.forename: Marília Pivetta
authors.initials: MP
authors.lastname: Rippe
authors.affiliation: Department of Stomatology, Federal University of Santa Maria, Santa Maria, RS, BRAZIL.
authors.forename: Gisele Jung
authors.initials: GJ
authors.lastname: Franciscatto
authors.affiliation: Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Ricardo Abreu
authors.initials: RA
authors.lastname: da Rosa
authors.affiliation: Department of Restorative Dentistry, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Luiz Felipe
authors.initials: LF
authors.lastname: Valandro
authors.affiliation: Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Marcus Vinícius Reis
authors.initials: MV
authors.lastname: Só
authors.affiliation: Department of Stomatology, Federal University of Santa Maria, Santa Maria, RS, BRAZIL.
authors.forename: Carlos Alexandre Souza
authors.initials: CA
authors.lastname: Bier
mesh_terms: D003481:Cuspid; D006801:Humans; D008437:Maxilla; D012390:Root Canal Therapy; D014082:Tooth Fractures