title: Influence of post placement in the fracture resistance of endodontically treated incisors veneered with direct composite.
abstract: BACKGROUND
  Veneer preparations are considered to weaken endodontically treated maxillary incisors. Prefabricated posts have been controversially indicated to reinforce endodontically treated teeth before final restoration.
  
  
  OBJECTIVE
  This in vitro study evaluated whether (1) veneer preparation in enamel or in enamel/dentin weakens endodontically treated maxillary incisors, (2) bonding of direct composite veneer restores the original strength of the unprepared teeth, and (3) use of prefabricated metal posts increases fracture resistance of prepared and restored teeth.
  
  
  METHODS
  Ninety extracted human maxillary central incisors were submitted to conventional root canal treatment. Specimens were randomly divided into 8 experimental groups (veneer preparation in enamel or dentin with/without post and with/without direct composite veneer restoration) and a control group (n = 10). Specimens were loaded to fracture, and the data were analyzed statistically.
  
  
  RESULTS
  Statistical analysis revealed that a conservative veneer preparation does not significantly reduce maxillary incisors' fracture resistance. For prepared incisors, bonding of direct composite veneer restored their original strength, and the use of posts did not increase their fracture resistance.
  
  
  CONCLUSIONS
  Conservative veneer preparations involving enamel and enamel/dentin did not significantly reduce the fracture resistance of endodontically treated maxillary incisors. In addition, restoration of the intraenamel preparations with direct composite resulted in teeth more resistant to fracture than teeth having restorations in dentin. The use of posts did not improve fracture resistance of endodontically treated maxillary incisors reduced and veneered with direct composite.
authors.affiliation: Federal University of Santa Catarina Florianópolis, Brazil.
authors.forename: L N
authors.initials: LN
authors.lastname: Baratieri
authors.forename: M A
authors.initials: MA
authors.lastname: De Andrada
authors.forename: G M
authors.initials: GM
authors.lastname: Arcari
authors.forename: A V
authors.initials: AV
authors.lastname: Ritter
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins; D003799:Dental Stress Analysis; D003801:Dental Veneers / Q000009:adverse effects; D006801:Humans; D007180:Incisor / Q000293:injuries; D008437:Maxilla; D011176:Post and Core Technique; D018709:Statistics, Nonparametric; D014082:Tooth Fractures / Q000209:etiology / Q000517:prevention & control*; D019553:Tooth, Nonvital
chemical_list: D003188:Composite Resins