title: Flexural strength of provisional crown and fixed partial denture resins.
abstract: BACKGROUND
  Provisional prostheses are subject to flexure under function. Selection of the appropriate material for their fabrication is difficult given the limited evidence-based information on the flexural strength of provisional resins.
  
  
  OBJECTIVE
  This study compared the flexural strength of 5 methacrylate-based resins and 8 bis-acryl resins used to fabricate provisional crowns and fixed partial dentures.
  
  
  METHODS
  Bar-type specimens were fabricated according to American National Standards Institute/American Dental Association specification 27. After being immersed in artificial saliva at 37 degrees C for 10 days, the specimens were fractured under 3-point loading in a universal testing machine at a crosshead speed of 0.75 mm/min. Maximal loads to fracture in Newtons were recorded. Mean flexural strengths were calculated in MPa (n = 10 per group). Comparisons were made with analysis of variance and Duncan's multiple range test (P<.05).
  
  
  RESULTS
  Mean flexural strengths ranged from 56.2 to 123.6 MPa. There were 4 statistically similar groups. The group with the highest strengths consisted of 4 bis-acryl materials (Provipont, Integrity, Protemp 3 Garant, and Luxatemp).
  
  
  CONCLUSIONS
  Within the limitations of this study, flexural strengths were material- rather than category-specific. Some, but not all, bis-acryl resins demonstrated significantly superior flexural strength over traditional methacrylate resins.
authors.affiliation: Department of Family Dentistry, College of Dentistry, University of Iowa, Iowa City, Iowa 52242, USA. debra-haselton@uiowa.edu
authors.forename: Debra R
authors.initials: DR
authors.lastname: Haselton
authors.forename: Ana M
authors.initials: AM
authors.lastname: Diaz-Arnold
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Vargas
mesh_terms: D000180:Acrylic Resins; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D019245:Compressive Strength; D003442:Crowns; D003794:Dental Restoration, Temporary; D003799:Dental Stress Analysis; D003830:Denture, Partial, Fixed; D003833:Denture, Partial, Temporary; D008422:Materials Testing; D018583:Pliability; D018709:Statistics, Nonparametric; D013718:Tensile Strength
chemical_list: D000180:Acrylic Resins; D017438:Bisphenol A-Glycidyl Methacrylate