title: Shear bond strength of an autopolymerizing repair resin to injection-molded thermoplastic denture base resins.
abstract: OBJECTIVE
  This study investigated the shear bond strength of an autopolymerizing repair resin to injection-molded thermoplastic denture base resins.
  
  
  METHODS
  Four injection-molded thermoplastic resins (two polyamides, a polyethylene terephthalate copolymer and a polycarbonate) were used in this study. The specimens were divided into eight groups according to the type of surface treatment given: (1) no treatment, (2) air abrasion with alumina, (3) dichloromethane, (4) ethyl acetate, (5) 4-META/MMA-TBB resin, (6) alumina and 4-META/MMA-TBB resin, (7) tribochemical silica coating or (8) tribochemical silica coating and 4-META/MMA-TBB resin. Half of the specimens in groups 1, 5, 6 and 8 were thermocycled for 10,000 cycles in water between 5-55°C with a dwell time of 1 min at each temperature. The shear bond strengths were determined.
  
  
  RESULTS
  The shear bond strengths to the two polyamides treated with alumina, dichloromethane and ethyl acetate and no treatment were very low. The greatest post-thermocycling bond strengths to polyamides were recorded for the specimens treated with tribochemical silica coating and 4-META/MMA-TBB resin (PA12: 16.4 MPa, PACM12: 17.5 MPa). The greatest post-thermocycling bond strengths to polyethylene terephthalate copolymer and polycarbonate were recorded for the treatment with alumina and 4-META/MMA-TBB resin (22.7 MPa, 20.8 MPa).
  
  
  CONCLUSIONS
  Polyamide was exceedingly difficult to bond to an autopolymerizing repair resin; the shear bond strength improved using tribochemical silica coating followed by the application of 4-META/MMA-TBB resin. Both polyethylene terephthalate copolymer and polycarbonate were originally easy to bond to an autopolymerizing repair resin. However, with 4-META/MMA-TBB resin, the bond was more secure.
authors: Division of Removable Prosthodontics, Fukuoka Dental College, Fukuoka, Japan. hamanaka@college.fdcnet.ac.jp
authors: Ippei
authors: I
authors: Hamanaka
authors: Hiroshi
authors: H
authors: Shimizu
authors: Yutaka
authors: Y
authors: Takahashi
mesh_terms: D003778:Dentures; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry*; D012117:Resins, Synthetic
chemical_list: D011108:Polymers; D012117:Resins, Synthetic