改良Δα用于评价非线性膨胀瓷-瓷结构匹配性的研究  

Modified thermal mismatch value Δα for evaluating thermal compatibility of multi-layer dental ceramic composites

作　　者：崔军[1] 刘学恒[1] 马练[1] 贾黎[1] 巢永烈[2] 

机构地区：[1]北京大学深圳医院口腔科,深圳518036 [2]四川大学华西口腔医院修复科

出　　处：《现代口腔医学杂志》2010年第3期201-204,共4页Journal of Modern Stomatology

基　　金：2009深圳市科技计划项目资助

摘　　要：目的尝试用二次函数ΔL/L=C+α1T+α2T2拟合陶瓷的热膨胀曲线,经过数学推导得到一个新的评价瓷-瓷结构热匹配性的方法-改良Δα,并用实验验证该方法的正确性。方法用热膨胀仪测定2种核瓷、1种烤瓷金属及5种饰面瓷材料的热膨胀曲线,对所有的试件数据进行直线回归(ΔL/L=C+αT)和二次回归(ΔL/L=C+α1T+α2T2),测得每种材料的回归系数α1,α2。热休克实验样本制作成10mm×1.6mm盘状的双层试件,测定其热休克抗力值。计算热休克实验每组样本的改良Δα值。回归分析评价热休克抗力值与改良Δα的相关性。结果所有的陶瓷材料热膨胀曲线均表现出非线性特征,二次回归得到的回归系数α1衡量曲线的倾斜程度,α2衡量曲线的弯曲程度。热休克抗力值与改良Δα呈高度相关性(R=0.817)。结论二次函数来描述陶瓷的热膨胀曲线方法可靠,能更加准确详细地描述瓷的膨胀特征。改良Δα可以用来评价全瓷系统的匹配性。Objective The purpose of this study was to use polynomial function ΔL/L= C＋α1 T＋α2 T2 to describe the thermal contraction behavior of dental porcelain. In addition,modified Δα method was proposed to evaluate thermal compatibility.Methods The thermal contraction curve of one dental alloy,two ceramic core and nine veneering porcelains were measured on cooling from 470℃ to 20℃ by means of a vertical differential pushrod thermal dilatometer. An equation was deduced to calculate thermal mismatch value （Δα） between substrate and veneer. Discs of eight substrate/veneer combinations （n=10） were fabricated for thermal shock testing. A regression analysis was performed to determine the relationship between the results of thermal shock test and the thermal mismatch value （Δα） on these combinations.Results In this study,all the ceramics showed non linear dimensional change during cooling. A high degree of correlation （R=0.817） was found between thermal shock test results and thermal mismatch value （Δα）.Conclusion Modified thermal mismatch value （Δα） is a promising approach for evaluation of thermal compatibility between substrate and veneer porcelain.

关 键 词：牙科陶瓷 热匹配性 热休克实验 

分 类 号：R783.1[医药卫生—口腔医学]