非贵金属铸造卡环弹性极限及其相应卡抱力的研究

目的　研究非贵金属铸造卡环的弹性极限及其相应卡抱力。方法　成品磨牙铸造卡环蜡经包埋、铸造、喷砂、超声波清洗后制得 5种钴铬合金和 1种 18 8镍铬不锈钢铸造卡环试件。应用万能材料试验机测试采集试件加载变形及其卸载回复全过程的电信号 ,通过A/D转换器将电信号转换成数字信号并贮存于计算机中 ;应用福州大学中心实验室基于MATLAB平台开发的计算机绘图软件处理分析、计算铸造卡环弹性极限及其相应卡抱力。结果　不同品牌的钴铬合金铸造卡环弹性极限及其相应卡抱力不同 ,18 8镍铬不锈钢铸造卡环的弹性极限及其相应卡抱力最低。在进入倒凹长度为 5 0mm、铸造卡环支撑处的厚度和宽度分别为 (0 71± 0 0 3)mm和 (1 31± 0 0 3)mm时 ,铸造钴铬合金卡环依材料生产厂商不同 ,其弹性极限范围是 0 2 8～ 0 33mm ,相应的卡抱力范围是14 4 2～ 19 2 8g。 结论　在临床工作中 ,应根据不同厂商生产的铸造钴铬合金 ,结合倒凹长度、坡度及卡环粗细选择进入倒凹的深度 ,以获得较理想的固位效果。

Study on elastic limit and relevant enclasp force of non-precious metal casting clasp

Objective To investigate the elastic limit and relevant enclasp force of the non-precious metal casting clasp. Methods Casting clasp samples of five cobalt-chromium alloys and one 18-8 nickel-chromium alloy were made from prefabricated clasp wax by invesing,casting,sandblasting,and ultrasonic cleaning. The process of casting clasp samples deflected by loading and returned by unloading was tested and electric signals were collected by an omnipotent material machine. The analog electric signal was converted to digital signal by an analog to digital converter and stored in a computer. The elastic limit and the relevant enclasp force were analyzed using a relative software. Results The elastic limit and the relevant enclasp force of the casting clasp made from the l 8-8 nickel-chromium alloy were smallest and those of the clasps made from the cobalt-chromium alloys in various brands were different. The range of the elastic limit of the cobalt-chromium alloy casting clasp with the length of 5.0 mm in undercut was 0.28 mm-0.33 mm and the relevant enclasp force was 14.42 g-l 9.28 g. Conclusions In clinic,we should select the suitable undercut deepness wherein the cobalt-chromium alloy casting clasps,according to different brands of the casting alloy,undercut length,undercut slope,and the clasp thickness.