Schug J, Pfeiffer J, Sener B, Mörmann W H
Station für Zahnfarbene und Computer-Restaurationen, Universität Zürich.
Schweiz Monatsschr Zahnmed. 1995;105(7):913-9.
The grinding precision of one Cerec-1 (C1) and one Cerec-2 (C2) CAD/CIM unit each was evaluated using standardized inlay-like (mod) samples (n = 40) of Vita Cerec Mk II porcelain and Dicor MGC glass ceramic. Typical dimensions (B, E, F, H) of the sampleS were measured and the standard deviations (SD) analysed statistically using the F-test. SD of C2-machined sample dimensions were significantly lower using both Vita, B: p < 0.05; E: p < 0.001; F: p < 0.001; H: p < 0.001, and Dicor MGC, B: p < 0.05; E: p < 0.001; F: p < 0.001; H: p < 0.01, than those machined with C1, indicating a strong improvement of grinding precision of C2 compared to C1. Accuracy of fit to human molar cavities of mod inlays machined with C1 (n = 6) and C2 (n = 6) was evaluated using a scanning electron microscope with 100x magnification. The width of the interfacial luting gap was generally lower in C2 inlays (56 +/- 27 microns) than with C1 (84 +/- 38 microns). Significant differences (t-test) were seen in margin sections "cervical line angles above CEJ" (C1 = 124 +/- 44/C2 = 59 +/- 30 microns, p < 0.05), "cervical line angles at CEJ" (C1 = 109 +/- 55/C2 = 67 +/- 27 microns, p < 0.05) and "gingival margin above CEJ" (C1 = 81 +/- 32 microns/C2 = 31 +/- 18 microns, p < 0.05).
分别使用Vita Cerec Mk II瓷和Dicor MGC玻璃陶瓷的标准化嵌体样（mod）样本（n = 40），对一台Cerec-1（C1）和一台Cerec-2（C2）CAD/CIM设备的磨削精度进行了评估。测量了样本的典型尺寸（B、E、F、H），并使用F检验对标准偏差（SD）进行了统计学分析。使用Vita时，C2加工样本尺寸的SD显著更低，B：p < 0.05；E：p < 0.001；F：p < 0.001；H：p < 0.001；使用Dicor MGC时，B：p < 0.05；E：p < 0.001；F：p < 0.001；H：p < 0.01，均低于C1加工的样本，这表明与C1相比，C2的磨削精度有了显著提高。使用放大100倍的扫描电子显微镜，评估了用C1（n = 6）和C2（n = 6）加工的mod嵌体与人类磨牙窝洞的贴合精度。C2嵌体的界面粘接间隙宽度通常（56±27微米）低于C1（84±38微米）。在边缘部分“牙骨质界上方的颈线角”（C1 = 124±44/C2 = 59±30微米，p < 0.05）、“牙骨质界处的颈线角”（C1 = 109±55/C2 = 67±27微米，p < 0.05）和“牙骨质界上方的牙龈边缘”（C1 = 81±32微米/C2 = 31±18微米，p < 0.05）观察到显著差异（t检验）。
