Asbia S, Ibbetson R, Reuben R L
University of Edinburgh, Postgraduate Dental Institute, Edinburgh, UK.
Technol Health Care. 2006;14(4-5):439-48.
This work is concerned with the performance, under dynamic compression, of the adhesives used to simulate cementation of gold crowns onto nickel chromium dies. A measurement system, based on the mounting of strain gauges onto the outer surface of the crowns, has been developed, which allows a semi-quantitative estimate of the state of adhesion. A preliminary study was carried out where miniature gauges were bonded onto the buccal, lingual, mesial and distal surfaces of gold crowns cast to fit onto a chromium-cobalt die, as a precursor to the final design of the instrumented crown. The crowns were then loaded in compression periodically measuring the strain at all four gauges. The results showed the load-strain relationship in fully, partially and uncemented crowns, along with repeated load-unload behaviour to close to the ultimate strength of the bond. The load-strain relationship is linear and repeatable and the slope varies over a factor of about 30 between the un-cemented and fully cemented crown, demonstrating that there is significant sensitivity to bond integrity. These results were used to determine the parameters for a systematic study of S-N relationships in restorative dentistry crowns.
本研究关注用于模拟金冠粘结到镍铬代型上的粘结剂在动态压缩下的性能。已开发出一种基于将应变片安装在冠外表面的测量系统，该系统能够对粘结状态进行半定量评估。进行了一项初步研究，将微型应变片粘贴在铸造的金冠的颊面、舌面、近中面和远中面上，该金冠适配于铬钴代型，作为带仪器冠最终设计的前期研究。然后对冠进行周期性压缩加载，同时测量所有四个应变片处的应变。结果显示了完全粘结、部分粘结和未粘结冠的载荷 - 应变关系，以及接近粘结极限强度的反复加载 - 卸载行为。载荷 - 应变关系呈线性且可重复，未粘结和完全粘结冠之间的斜率变化约为30倍，这表明对粘结完整性具有显著敏感性。这些结果被用于确定对修复牙科冠中S - N关系进行系统研究的参数。
