Steiner P J, Kelly J R, Giuseppetti A A
National Naval Dental Center, Bethesda, Maryland, USA.
Int J Prosthodont. 1997 Jul-Aug;10(4):375-80.
This study evaluated dilatometric data for predicting ceramic-ceramic compatibility for porcelains fired on central incisor copings (n = 72) of high expansion colored IPS-Empress porcelain. Nine body porcelains (leucite 0 wt% to 51 wt%) were each fired onto eight copings. Cracks were detected at 10 x magnification using transilluminating light. Failure was defined as the presence of at least one crack and probability of failure (Pf) as the ratio of failed to total crowns. Thermal contraction coefficients (alpha) were determined using four bars of each porcelain following the protocol of ISO 9693. Absolute differences in thermal contraction, magnitude of delta alpha, between core and test porcelains were plotted against Pf and curve fit. Significant differences in alpha were found among the porcelains tested (ANOVA, 95% Tukey); the alpha values ranged from 7.92 to 17.83 x 10(-6)/degree C; Pf ranged from 0 to 1. Compatible porcelains (no cracks during any firing of all eight crowns) had magnitude of delta alpha values less than 1 x 10(-6)/degree C. Absolute values (magnitude of delta alpha) were surprisingly predictive of Pf given the very different cooling rates (dilatometry versus dental lab) and the relatively complex crown shape. Standard dilatometry may be useful for predicting the compatibility of ceramic-ceramic systems. Three porcelains, IPS-Empress dentin, Duceram, and Will-Ceram were successfully used for veneering IPS Empress cores.
本研究评估了膨胀测量数据在预测高膨胀彩色IPS-Empress瓷中央切牙全冠（n = 72）上烧制的瓷与瓷之间兼容性方面的作用。九种体瓷（白榴石含量从0 wt%至51 wt%）分别烧制在八个全冠上。使用透照光在10倍放大倍数下检测裂纹。失败定义为至少存在一条裂纹，失败概率（Pf）为失败全冠数与总全冠数之比。按照ISO 9693标准，使用每种瓷的四根试条测定热收缩系数（α）。将核瓷与测试瓷之间的热收缩绝对差值（δα大小）与Pf作图并进行曲线拟合。在所测试的瓷之间发现α存在显著差异（方差分析，95% Tukey检验）；α值范围为7.92至17.83×10⁻⁶/℃；Pf范围为0至1。兼容的瓷（所有八个全冠在任何一次烧制过程中均无裂纹）的δα值大小小于1×10⁻⁶/℃。鉴于冷却速率差异极大（膨胀测量法与牙科实验室）以及全冠形状相对复杂，绝对差值（δα大小）令人惊讶地能够预测Pf。标准膨胀测量法可能有助于预测陶瓷 - 陶瓷系统的兼容性。三种瓷，IPS-Empress牙本质瓷、Duceram瓷和Will-Ceram瓷成功用于IPS Empress核瓷的贴面。
