Krishna C M, Bhat S, Shetty P
Department of Prosthodontics and Maxillofacial Prosthetics, College of Dental Surgery, Mangalore-575 001, India.
Indian J Dent Res. 2001 Apr-Jun;12(2):89-92.
This in vitro study compared the load necessary to cause porcelain bond failure on porcelain covering the labial and palatal surfaces compared with porcelain covering only labial surface in metal ceramic crowns of maxillary anterior teeth. 30 metal ceramic crowns for maxillary central incisor tooth were fabricated in two groups (Groups A and Group B) (15 samples in each group). In group A, palatal ceramo-metal junction was placed at cervical 1/5th of palatal surface. In Group B the palatal ceramo-metal junction was placed at palato incisal line angle and these crowns were subjected to load using Instron testing machine. Mean failure load for group A is statistically highly significant than Group B. (P value = 0.0025). But both these values are higher than the reported mean maximal incising forces.
这项体外研究比较了在上颌前牙金属烤瓷冠中，覆盖唇面和腭面的瓷发生瓷结合失败所需的负荷与仅覆盖唇面的瓷的情况。制作了30个上颌中切牙的金属烤瓷冠，分为两组（A组和B组）（每组15个样本）。在A组中，腭侧瓷-金属结合部位于腭面颈1/5处。在B组中，腭侧瓷-金属结合部位于腭切缘线角处，然后使用英斯特朗试验机对这些冠施加负荷。A组的平均失败负荷在统计学上比B组高得多（P值 = 0.0025）。但这两个值均高于报道的平均最大切割力。
