title: Fracture resistance of weakened roots restored with different intracanal retainers.
abstract: The purposes of the study were to evaluate the effect of mechanical cycling (MC) on the fracture resistance of endodontically treated weakened roots restored with different intraradicular retainers and to analyze the failure mode. Eighty bovine roots were prepared and restored: 20 roots were reconstructed with cast post-and-cores (CPCs); 20 with fiber posts (FPs); 20 with fiber posts with larger coronal diameter (FPLs); and 20 with anatomic posts (APs). Metal crowns were cemented in all the roots. Half of specimens from each restoration strategy (n = 10) were submitted to MC: CPC-MC, FP-MC, FPL-MC, and AP-MC. The specimens were subjected to a fracture resistance test. The results showed that the type of retainer used was statistically significant (P < 0.0004). The CPC specimens demonstrated a fracture resistance similar to that of the APs, but greater than that of the FPs and FPLs. MC was statistically significant (P < 0.003) and affected AP-MC fracture resistance, which was lower than that of CPC-MC and similar to those of FP-MC and FPL-MC.
authors.forename: Juliana
authors.initials: J
authors.lastname: Broch
authors.forename: Ana Maria Estivalete
authors.initials: AM
authors.lastname: Marchionatti
authors.forename: Cesar Dalmolin
authors.initials: CD
authors.lastname: Bergoli
authors.forename: Luiz Felipe
authors.initials: LF
authors.lastname: Valandro
authors.forename: Osvaldo Bazzan
authors.initials: OB
authors.lastname: Kaizer
mesh_terms: D000818:Animals; D002417:Cattle; D003442:Crowns; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D018704:Orthodontic Retainers; D011176:Post and Core Technique; D018915:Root Canal Preparation / Q000379:methods; D014082:Tooth Fractures / Q000517:prevention & control*; D014092:Tooth Root / Q000293:injuries
keywords: fracture resistance; nonvital tooth; weakened teeth