AN EXPERIMENTAL STUDY ON THE DIMENSIONAL CHANGES OF RELINED DENTURES AND MECHANICAL PROPERTIES AND SURFACE TEXTURES OF SEVERAL RESINS USED IN DENTURE RELINING

수종 레진으로 의치상 조직면 개조시 의치상의 크기변화와 물리적 성질 및 표면상태 비교 연구

The purpose of this study was to evaluate and compare the dimensional changes of relined dentures with a light-curing resin, a heat-curing resin, and a direct, hard reline resin. And also to measure the transverse strength, impact strength, surface hardness of the three resins used in relining. The surface textures of three resins also of evaluated by using scanning electron microscope. Through analyses on the data from this study, the following conclusions were obtained. 1. Impact strength of heat-curing resin was highest, and direct, hard reline resin higher, light-curing resin lowest. 2. Transverse strength of heat-curing resin was highest, and direct, hard reline resin and light-curing resin was lower and not signiicantly different. 3. Surface hardness of light-curing resin was lighest, heat-curing resin higher, and direct, hard reline resin was lowest. 4. After storage of the relined dentures for 1 day and 1 week in water at room temperature, linear shrinkage of distance between the reference points in the maxillary base relined with direct, hard reline resin was lowest, and those relined with light-curing resin and heat-curing resin were lower and were not significantly different. 5. After storage for 4 weeks in orator at room tempeature, linear shrinkage of distance between ridge crests of dentures relined with heat-curing resin was highest and that of distance between denture borders was not significantly different. 6. The dimensional changes of relined dentures during storage in water was not significant except those of distance between denture borders relined with light-curing resin at 1 day and 1 week storage in water. 7. At low magnification (x40) of SEM examination, the surface textures of three resins were similar except light-curing resin which had some defects. At high magnification (x200), the surface textures of hard, direct reline resin were smooth with little defects, but those of heat-curing resin and light-curing resin w ere irregular.