title: Repair of denture base resin using woven metal and glass fiber: effect of methylene chloride pretreatment.
abstract: BACKGROUND
  A durable repairing system for denture base fracture is desired to avoid recurrent fracture. Purpose. This study evaluated the strength and modulus of elasticity of repaired acrylic specimens reinforced with various processes.
  
  
  METHODS
  Transverse strength and modulus of elasticity of repaired acrylic denture base specimens were evaluated with a 3-point bending test and compared with a heat-polymerized control. Autopolymerizing acrylic resin was used with woven metal fiber and glass fiber with and without methylene chloride surface treatment (n = 6 per group). The specimens were cut in half and fixed in a metal mold to obtain a space for placing the repairing resin. A cavity was prepared when metal or glass fiber was used. All specimens were stored in 37 degrees C distilled water for 48 hours before the test. All data were statistically analyzed with 1-way ANOVA, and differences among groups were analyzed with Fisher test (P< or =.05).
  
  
  RESULTS
  The mean value of the transverse strength for the control was 87.2 MPa. The specimens repaired by glass fiber with methylene chloride surface treatment exhibited the highest transverse strength (96.8 MPa), which was significantly higher than that of the control (P< or =.05). The elastic modulus of the specimens repaired by glass fiber with methylene chloride surface treatment (4189.3 MPa) was significantly greater than that of the control (2683.7 MPa) at a 95% level of confidence. The values of transverse strength and elastic modulus were highest when the surface treatment was combined with a reinforcing glass fiber.
  
  
  CONCLUSIONS
  Reinforcement with glass fiber and methylene chloride pretreatment produced transverse strength and a modulus of elasticity higher than the control.
authors.affiliation: School of Dentistry, Nihon University, Tokyo, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Nagai
authors.forename: K
authors.initials: K
authors.lastname: Otani
authors.forename: Y
authors.initials: Y
authors.lastname: Satoh
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
mesh_terms: D000180:Acrylic Resins; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003819:Denture Bases; D003780:Denture Repair / Q000379:methods*; D004548:Elasticity; D005898:Glass; D008422:Materials Testing; D008670:Metals; D008752:Methylene Chloride / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D008670:Metals; D013501:Surface-Active Agents; C009753:fiberglass; C112073:unifast II; D008752:Methylene Chloride