title: Evaluation of the rigidity of dentures made of injection-molded materials.
abstract: Dentures made of 2 different types of injection-molded thermoplastic resins (polyamide resin and polyester resin) and a denture made of conventional heat-polymerized resin were used to create an experimental model of a mandibular molar region with a two-tooth gap. In the experimental model, a force of 100 N was applied onto the mesial fossa of the first molars of the dentures, and comparisons were performed by measuring the pressure applied under the denture base and the subsidence rate of the denture. The polyamide resin denture showed the highest subsidence, exerted the highest pressure on the underlying mucosa, and showed significant differences with the other types of dentures. The findings showed that polyamide resins have the lowest degree of elasticity, and that when resins with such low elasticities are used in the denture base, they should preferably be reinforced with metals.
authors.affiliation: Removable Partial Prosthodontics, Masticatory Function Rehabilitation, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. juropro1@tmd.ac.jp
authors.forename: Juro
authors.initials: J
authors.lastname: Wadachi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sato
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Igarashi
mesh_terms: D003188:Composite Resins; D016734:Dental Clasps; D003799:Dental Stress Analysis; D003819:Denture Bases; D003779:Denture Design / Q000379:methods*; D003827:Denture, Complete, Upper; D004548:Elasticity; D006358:Hot Temperature; D007267:Injections; D008422:Materials Testing; D003765:Models, Dental; D009061:Mouth Mucosa; D009757:Nylons; D010969:Plastics / Q000737:chemistry*; D011076:Polycarboxylate Cement; D011091:Polyesters; D019904:Polymethyl Methacrylate; D011312:Pressure; D013314:Stress, Mechanical
chemical_list: D003188:Composite Resins; D009757:Nylons; D010969:Plastics; D011076:Polycarboxylate Cement; D011091:Polyesters; C005506:polycarbonate; D019904:Polymethyl Methacrylate