title: Mechanical properties of denture base resins: an evaluation.
abstract: BACKGROUND
  Acrylic resin dentures are susceptible to fracture after clinical use, which is a problem of concern in prosthodontics. Impact failure outside the mouth and flexure fatigue failure in the mouth are two most important causes of fracture of denture base.
  
  
  OBJECTIVE
  This study evaluated the transverse deflection and transverse strength of four commercial brands of heat cure acrylic resin (Stellon, Acrylin-H, Trevalon and Trevalon-HI).
  
  
  METHODS
  An experimental design was adapted. Twenty-four rectangular strip specimens, six for each group, were prepared. Strips were finished on the edges and equally from the both the molded surfaces to make strips of specific dimensions. The tests were conducted mainly in accordance with the American Dental Association Specification no. 12/ISO: 1567-1981 (ISO: 6887-1986) for denture base polymer. The transverse deflection and transverse strength were measured by Instron testing machine. Intergroup differences were assessed using student "t" test.
  
  
  RESULTS
  The heat cure denture base material D (Trevalon "HI") had the minimum mean value of transverse deflection under different loads. Trevalon "HI" also had minimum value of mean transverse strength among different brands of acrylic resins. There was no statistically significant variation between Stellon, Acrylin-H and Trevalon, but variation was significantly higher with D (Trevalon "HI") vs. Stellon, Acrylin-H and Trevalon.
  
  
  CONCLUSIONS
  The heat cure denture base material D (Trevalon "HI") was the strongest and C (Trevalon) was the weakest among all materials used in this study. The study showed that the deflection of various denture base resins (A to D) increases proportionately with the increase in load.
authors.affiliation: Department of Prosthodontics and Dental Material Sciences, Faculty of Dental Sciences, CSM Medical University, Lucknow, India.
authors.forename: Pooran
authors.initials: P
authors.lastname: Chand
authors.forename: Chandra Bhusan Singh
authors.initials: CB
authors.lastname: Patel
authors.forename: Balendra Pratap
authors.initials: BP
authors.lastname: Singh
authors.forename: Raghuwar Dayal
authors.initials: RD
authors.lastname: Singh
authors.forename: Kamleshwar
authors.initials: K
authors.lastname: Singh
mesh_terms: D000180:Acrylic Resins; D003764:Dental Materials; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D003819:Denture Bases; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008768:Methylmethacrylates; D018583:Pliability; D013314:Stress, Mechanical
chemical_list: D000180:Acrylic Resins; D003764:Dental Materials; D008689:Methacrylates; D008768:Methylmethacrylates; C070869:stellon C; C029883:Trevalon universal