[The influence of the adhesive resin for the deformation of the metallic plate].

From both vital and denture sides, the design of denture in dental clinic needs taking care of various viewpoints; alleviation of the adverse effect on the periodontium is necessary on the vital side, and prevention of possible rupture of the denture at its functioning and taking hygienic measures are necessary on the denture side. Utilization of the metal and adhesive, 4-META containing resin (hereinafter referred to as adhesive resin) in the design of denture has been reported to be not only hygienically advantageous because of difficult adhesiveness of bacterial flora due to solid union between the metal and the resin, but also less in danger of the denture rupture from its finishing line portion. However, a few reports have been made on the analysis of the correlation between the mechanical strength of the whole of denture and the use of adhesive resin and on the deformation of the metallic frame due to curing shrinkage of adhesive resin. In the present study, in terms of these problems, utilizing the modal analysis applying a vibrato-logical technique and the strain gauge device appropriate for the determination of the time-course, samples of chrome-cobalt alloy and of partial denture were examined for the influence of inserted adhesive and non-adhesive resins upon them. The following results were obtained: 1. The results of the determination by the strain gauge method revealed that the insertion of adhesive resin tended to have more displacement volume for more insertion volume and for thinner chrome-cobalt alloy sample and that of non-adhesive resin had practically no adhesive force, suggesting a small deformation of the sample due to curing shrinkage, with little interlocking force. 2. The results of modal analysis revealed that the insertion of the adhesive resin onto the denture sample led to an increase in mechanical strength and a rigid body modality of the activity at the finishing line portion compared with the non-adhesive resin. 3. From the results of the determination by the strain gauge method and of the modal analysis, the application of adhesive resin was suggested to increase the intensity of denture.