上顎中切歯における歯冠修復歯の伝熱的様相に関する研究 陶材焼付鋳造冠とオールセラミックスクラウンについて

Abstract

Unsteady temperature distribution was analyzed by using a two-dimensional finiteelement method. An excessive thermal stimuli was added to a maxillary central incisor which was restored with porcelain fused to metal crown and all ceramics crown. The results were as follows:1. In the pulp, the pulp horn showed earliest temperature response.2. Temperature distributions with time in the porcelain fused to metal crown were different from those in the all ceramics crown. Incase of all ceramics crown in thermal loading condition B (the lingual surface and part of the labial surface), the temperature rises on the labial side were late, and the influence orthermal distribution according to the kind of restorative materials was greater than porcelain fused to metal crown.3. The temperature distribution with time under different thermal loading conditions was different for the porcelain fused to metal crown and all ceramics crown. In case of porcelain fused to metal crown in thermal loading condition B (the lingual surface and part of the labial surface), the temperature rises on the labial side were early, and it was similar with thermal distribution of loading condition A (all surface), the influence on thermal distribution according to the loading conditions was smaller than all ceramics crown.4. Thermal loading condition A (all surface) gave higher temperature, 1.8°C, in porcelain fused to metal crown and, 2.6°C, in all ceramics crown at point P (the pulp horn) than thermal loading condition B (the lingual surface and part of the labial surface).5. The highest temperature at point P (the pulp horn) in all ceramics crown was higher than in porcelain fused to metal crown and the highest temperature at point S (the lingual side near the center in coronal pulp) in porcelain fused to metal crown was higher than in all ceramics crown.