[Mechanical properties of swagged stainless steel denture with 4-META adhesive resin].

Recent advances in adhesive resin materials containing 4-META have broadened the technique used in prosthodontic dentistry. Hayakawa et al. have developed a new method for a swaged metal plate system using 5 wt% 4-META resin. This system eliminated the need to build in retention of acrylic resin in customary swaged dentures and also eliminated difficult and time consuming laboratory procedures. In this study, mechanical properties of stainless steel dentures using that system were investigated. This type of denture was also compared with a Co-Cr alloys cast denture and an acrylic denture, using an uniform bending test of upper complete denture with steel wings exerting stress. Findings are as follows: The apparent flexual rigidity and bending strength of stainless steel dentures are superior to those of acrylic resin dentures, but are inferior to those of Co-Cr alloys cast dentures. At the breaking point, acrylic resin with 4-META completely breaks away from the metal surface in stainless steel dentures, but not in Co-Cr alloys cast dentures with regular resin and its retention. Therefore, stainless steel dentures need to have retention of acrylic resin for reinforcement.