Application of titanium alloys to porcelain fuse to metal crown.

钛是一种极具吸引力的牙齿修复材料，因为它具有优异的特性，但它很难铸造。我们一直在研究一些稳定的钛合金，它们的熔合温度比纯钛低。为了牙科临床使用，这些合金必须能够与牙科瓷结合，因为牙科的审美要求。这一次，我们研究了Au-1.6wt% Ti合金。评价了烤瓷与金属冠的结合强度和烤瓷与金属冠的配合度。Au-1.6 wt% Ti合金的热膨胀系数与传统金属烤瓷用贵金属合金的热膨胀系数相近。Au-1.6 wt% Ti合金的结合强度高于ISO 9693规定的最小值25 MPa。EPMA观察表明，合金侧在金属-陶瓷界面处有Ti和O含量的积累。研究了基牙终点线曲率对冠配合的影响。用Au-1.6 wt% Ti合金铸造的金属烤瓷冠与用常规贵金属合金铸造的烤瓷烤瓷冠精度相当。在铸态标本中，终点线曲率越大，冠状体中缘和远端缘比唇缘和舌缘出现更大的间隙。烤瓷后，面贴面型金属陶瓷冠终点线曲率越大，唇缘间隙越大，au -1.6wt% Ti合金与对照珍贵合金铸造精度相当，基台终点线曲率对烤瓷与金属冠边缘配合有显著影响。

Titanium is an attractive dental restorative material because of its excellent characteristics, however it is difficult to cast. We have been investigating some beta-stabilized titanium alloys which have lower fusion temperatures than pure titanium. For dental clinical use, these alloys must be able to bond to dental porcelains because of the esthetic demands of dentistry.This time, we investigated the Au-1.6wt% Ti alloy. The bond strength to porcelain and fitness of porcelain fused to metal crown were evaluated.The coefficient of thermal expansion of the Au-1.6 wt% Ti alloy showed a close value to that of conventional precious metal alloys for porcelain fused to metal crown. Bonding strength of the Au-1.6 wt% Ti alloy was higher than 25 MPa, the minimum value specified in ISO 9693. EPMA observation showed an accumulation of Ti and O contents on the alloy side at the metal-ceramic interface.Then we investigated the effect of abutment finish-line curvature on the fit of crowns. The metal ceramic crowns cast in Au-1.6 wt% Ti alloy had accuracy as good those as-cast in control of conventional precious metal alloys for porcelain fused to metal crown.In the as-cast specimens, the greater the finish line curvature, the mesial and distal margins of copings exhibited larger gaps than labial and lingual margins.After porcelain application, for metal ceramic crowns of the facial-veneered type, the greater the finish line curvature, the larger the labial marginal gap became.Au-1.6wt% Ti alloy had equivalent accuracy to those that cast in control precious alloy, and the abutment finish-line curvature had a significant effect on the marginal fit of porcelain fused to metal crowns.