title: Controlled polymerization system for fabricating precise dentures.
abstract: BACKGROUND
  Most processed resin denture bases do not fit the cast accurately because of polymerization changes in the resin. The fit is more noticeable in the palate between the denture base and the cast. Therefore, development of a polymerization system that will improve the fit of a denture base to the cast is lack of worth considering to improve the fit and retention of the denture.
  
  
  OBJECTIVE
  A newly developed polymerization system for dentures is presented that results in excellent adaptability of the denture base to the cast when compared with 2 other polymerization systems.
  
  
  METHODS
  Forty-five maxillary dentures were made with 3 resins and 3 polymerization systems (a new polymerization system, SR-Ivocap system, original microwave polymerization system). Each denture and cast was sectioned through the second molar area parallel to the posterior border. Discrepancies between denture base and stone cast were measured at several points immediately after polymerization and after 30 days of immersion in water. In addition, disks of 3 materials processed in each system were examined for absorption of water and hardness at 2 measurement stages. Data were analyzed with the split-plot or 2-way ANOVA test.
  
  
  RESULTS
  Dentures made with the new polymerization system had significantly smaller discrepancies, compared with dentures processed with the SR-Ivocap system and the microwave method. The amount of water absorption of the resin disks processed by the new system was less than the disks made by the other 2 systems. Dentures made with the new system exhibited significantly better adaptation to the cast than those made with the other 2 systems.
  
  
  CONCLUSIONS
  The new polymerization system produced a more accurate method of processing dentures when fit was compared with the fit of dentures made with the other 2 denture base resins.
authors.affiliation: Osaka University, Faculty of Dentistry, Osaka, Japan, Department of Dental Materials Science and Technology. terachan@dent.osaka-u.ac.jp
authors.forename: F
authors.initials: F
authors.lastname: Teraoka
authors.forename: J
authors.initials: J
authors.lastname: Takahashi
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000704:Analysis of Variance; D017076:Computer-Aided Design; D003819:Denture Bases; D003779:Denture Design / Q000379:methods*; D004055:Differential Thermal Analysis; D006244:Hardness; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D003765:Models, Dental; D011108:Polymers / Q000737:chemistry; D017755:Prosthesis Fitting; D018709:Statistics, Nonparametric; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D011108:Polymers; D014867:Water