title: Influence of ferrule, post system, and length on biomechanical behavior of endodontically treated anterior teeth.
abstract: BACKGROUND
  The aim of this study was to evaluate the influence of post system, length, and ferrule on biomechanical behavior of endodontically treated anterior teeth.
  
  
  METHODS
  The investigation was conducted by using laboratory tests and 3-dimensional finite element analysis. Eighty bovine incisors were selected and divided into 8 treatment groups (n = 10) with absence of ferrule and 2.0 mm of ferrule, restored with glass fiber post or cast post and core, and 12.0 and 7.0 mm of post length. The specimens were loaded at 135° angle, and the strain was measured by using strain gauge method. Specimens were subsequently loaded until fracture. Strain and fracture resistance results were analyzed by 3-way analysis of variance and Tukey honestly significant difference tests (α = 0.05). Three-dimensional models of a maxillary central incisor were generated with the same treatment variations used in laboratory tests. Each model was subjected to 100 N oblique loads. Results were evaluated by von Mises criterion.
  
  
  RESULTS
  Ferrule was a determining factor in the strain, fracture resistance, and fracture pattern. In the absence of ferrule, the use of fiberglass posts represents a conservative choice from the standpoint of the fracture patterns observed. The length of 7 mm for cast post and cores produced high rates of root fractures. Finite element analysis showed that glass fiber post showed homogeneous stress distribution, whereas cast post showed stress concentration into root canal.
  
  
  CONCLUSIONS
  Post length influenced only the cast post strain and stress distribution. The ferrule groups always showed more satisfactory stress distribution and fracture resistance.
authors: Department of Restorative Dentistry and Dental Materials, Dentistry School, Federal University of Uberlandia, Minas Gerais, Brazil. Electronic address: paulocesarfs@yahoo.com.br.
authors: Paulo César Freitas
authors: PC
authors: Santos-Filho
authors: Department of Restorative Dentistry and Dental Materials, Dentistry School, Federal University of Uberlandia, Minas Gerais, Brazil.
authors: Crisnicaw
authors: C
authors: Veríssimo
authors: Department of Restorative Dentistry and Dental Materials, Dentistry School, Federal University of Uberlandia, Minas Gerais, Brazil.
authors: Paulo Vinícius
authors: PV
authors: Soares
authors: Department of Restorative Dentistry and Dental Materials, Dentistry School, Federal University of Uberlandia, Minas Gerais, Brazil.
authors: Rebeca Carniello
authors: RC
authors: Saltarelo
authors: Department of Restorative Dentistry and Dental Materials, Dentistry School, Federal University of Uberlandia, Minas Gerais, Brazil.
authors: Carlos José
authors: CJ
authors: Soares
authors: Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil.
authors: Luis Roberto
authors: LR
authors: Marcondes Martins
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry; D003198:Computer Simulation; D003722:Dental Alloys / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D020342:Finite Element Analysis; D005898:Glass / Q000737:chemistry; D021621:Imaging, Three-Dimensional / Q000379:methods; D008954:Models, Biological; D011176:Post and Core Technique / Q000295:instrumentation; D019279:Resin Cements / Q000737:chemistry; D018915:Root Canal Preparation / Q000379:methods; D013314:Stress, Mechanical; D014082:Tooth Fractures / Q000503:physiopathology; D019231:Tooth Preparation, Prosthodontic / Q000295:instrumentation*; D014092:Tooth Root / Q000293:injuries; D019553:Tooth, Nonvital / Q000628:therapy*
chemical_list: D003188:Composite Resins; D003722:Dental Alloys; D003764:Dental Materials; C483701:Rely X Unicem; D019279:Resin Cements; C009753:fiberglass
keywords: Endodontically treated teeth; fracture resistance; glass fiber posts; strain-gauge; stress distribution