Bailey J H
Department of Restorative and Prosthetic Dentistry, Ohio State University, College of Dentistry, Columbus.
J Prosthet Dent. 1993 Mar;69(3):267-9. doi: 10.1016/0022-3913(93)90104-v.
This study compared the microhardness of one- and two-piece cast post cores. Twenty 0.070 inch Whaledent "burn-out" posts were invested in a phosphate investment, cast, and bench cooled to room temperature. Five samples, were grouped by Sturdicast or Midas metal and by casting technique. The specimens were cast in matched pairs with one of each technique per casting ring. The Vickers hardness number sites were centered on the post diameter with the core-to-post head junction used as a baseline, at the following sites: (1) 1.5 mm into the core to post head assembly; (2) at the junction of the post to the post head and core assembly; (3) 1 mm into the post; (4) 2 mm into the post; and (5) 3 mm into the post. There were no significant differences in microhardness at the sites tested for metal or casting technic (p < 0.05). This indicated that a two-piece post and core has similar hardness values to the one-piece casting.
本研究比较了一体式和两件式铸造桩核的显微硬度。将20根0.070英寸的Whaledent“失蜡”桩放入磷酸盐包埋材料中包埋、铸造，并在工作台上冷却至室温。5个样本按Sturdicast或Midas金属以及铸造技术进行分组。标本以配对方式铸造，每个铸圈每种技术各一个。维氏硬度测试点以桩直径为中心，以桩核与桩头的交界处为基线，位于以下部位：(1) 进入桩核与桩头组件1.5毫米处；(2) 桩与桩头及桩核组件的交界处；(3) 进入桩内1毫米处；(4) 进入桩内2毫米处；(5) 进入桩内3毫米处。对于金属或铸造技术，在测试部位的显微硬度没有显著差异(p < 0.05)。这表明两件式桩核与一体式铸造的硬度值相似。
