title: Influence of the remaining coronal structure on the resistance of teeth with intraradicular retainer.
abstract: The aim of this study was to compare the resistance of endodontically treated teeth with intraradicular retainer different amounts of remaining coronal structure. Fifty freshly extracted maxillary canines were endodontically treated and randomly assigned to five groups (n=10), as follows: group 1 (control) = teeth with custom cast post and core; group 2 = teeth without remaining coronal structure; group 3, 4 and 5 = teeth with 1 mm, 2 mm and 3 mm of remaining coronal structure, respectively. All specimens in groups 2 to 5 were restored with prefabricated post and resin core. The teeth were embedded in acrylic resin and the fracture strength was measured on a universal testing machine at 45 degrees to the long axis of the tooth until failure. Data were analyzed statistically by one-way analysis of variance and Tukey's test. There was no significant differences (p>0.05) between the control group and group 2, and between groups 3, 4 and 5 (p>0.05). Control group and group 2 had significantly higher resistance strength than groups 3, 4 and 5 (p<0.00001). The findings of this study showed that teeth without remaining coronal structure had significantly higher fracture strength than those with remaining coronal structure (1 mm, 2 mm and 3 mm). When the dental crown was not completely removed, the amount of remaining coronal dentin did not significantly affect the fracture strength of endodontically treated teeth with intraradicular retainer.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry of Bauru, University of São Paulo, Bauru, SP, Brazil. jeffripe@rocketmail.com
authors.forename: Jefferson Ricardo
authors.initials: JR
authors.lastname: Pereira
authors.forename: Tatiany de Mendonça
authors.initials: Tde M
authors.lastname: Neto
authors.forename: Vinícius de Carvalho
authors.initials: Vde C
authors.lastname: Porto
authors.forename: Luiz Fernando
authors.initials: LF
authors.lastname: Pegoraro
authors.forename: Accácio Lins
authors.initials: AL
authors.lastname: do Valle
mesh_terms: D000096:Acetone / Q000737:chemistry; D000535:Aluminum / Q000737:chemistry; D002484:Cementation / Q000379:methods; D003188:Composite Resins / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D003481:Cuspid / Q000503:physiopathology*; D003722:Dental Alloys / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry; D003804:Dentin / Q000503:physiopathology; D005899:Glass Ionomer Cements / Q000737:chemistry; D006171:Gutta-Percha / Q000627:therapeutic use; D006801:Humans; D011109:Polymethacrylic Acids / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011176:Post and Core Technique; D019279:Resin Cements / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000379:methods; D012822:Silicon Dioxide / Q000737:chemistry; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D019228:Tooth Crown / Q000503:physiopathology*; D014082:Tooth Fractures / Q000503:physiopathology; D019246:Tooth Preparation / Q000379:methods; D015040:Zirconium / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003722:Dental Alloys; D003764:Dental Materials; D005899:Glass Ionomer Cements; D011109:Polymethacrylic Acids; C528569:Rely-X; D019279:Resin Cements; D012387:Root Canal Filling Materials; C083568:Z100 composite resin; C444444:prime and bond 2.1; D013193:Stainless Steel; D000096:Acetone; D012822:Silicon Dioxide; D003300:Copper; D006171:Gutta-Percha; D019904:Polymethyl Methacrylate; D015040:Zirconium; D000535:Aluminum