Division of Prosthodontics, College of Dentistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
J Prosthet Dent. 2010 Feb;103(2):80-90. doi: 10.1016/S0022-3913(10)60010-8.
The clinical performance and failure mechanisms of recently introduced ceramic crown systems used to restore posterior teeth have not been adequately examined.
The purpose of this prospective clinical study was to evaluate and compare the clinical performance of 2 new ceramic crown systems with that of metal ceramic crowns using modified United States Public Health Services (USPHS) criteria.
Ninety posterior teeth requiring crown restorations in 48 patients were randomized into 3 equal groups (n=30) for which different crown systems were used: an experimental hot-pressed glass ceramic based on a modified lithium disilicate ceramic (IPS e.max Press), an alumina-coping-based ceramic (Procera AllCeram), and a metal ceramic (Simidur S 2 veneered with IPS Classic Porcelain). The crowns were assessed over 3 years using the modified USPHS criteria. Crowns that developed visible cracks were sectioned and removed, and the surfaces were analyzed using a scanning electron microscope (SEM). The data were analyzed using the Kruskal-Wallis nonparametric statistical test, followed by the Mann-Whitney test with Bonferroni correction (alpha=.05).
USPHS evaluation showed that the IPS e.max Press and metal ceramic crowns experienced fewer clinical changes than Procera AllCeram. Visible roughness, wear, and deformity were noticed in occlusal contact areas of Procera AllCeram crowns. SEM images showed well defined wear facets in both ceramic crown systems. Kruskal-Wallis tests showed a significant difference (P<.05) in Alpha scores among the 3 crown systems. Mann-Whitney tests showed significant differences among groups.
IPS e.max Press crowns demonstrated clinical behavior comparable to Procera AllCeram and metal ceramic crowns, but the wear resistance of this crown type was superior to the Procera AllCeram crowns, according to modified USPHS criteria.
最近推出的用于修复后牙的陶瓷冠系统的临床性能和失败机制尚未得到充分检查。
本前瞻性临床研究的目的是使用改良的美国公共卫生服务（USPHS）标准评估和比较两种新型陶瓷冠系统与金属陶瓷冠的临床性能。
48 名患者的 90 颗需要冠修复的后牙随机分为 3 组（每组 30 颗），分别使用不同的冠系统：一种基于改良锂硅二酸盐陶瓷的实验性热压玻璃陶瓷（IPS e.max Press）、一种氧化铝覆盖陶瓷（Procera AllCeram）和一种金属陶瓷（Simidur S 2 覆以 IPS Classic Porcelain）。使用改良的 USPHS 标准在 3 年内评估这些牙冠。出现可见裂纹的牙冠被切开并取出，使用扫描电子显微镜（SEM）分析牙冠表面。使用 Kruskal-Wallis 非参数统计检验分析数据，然后使用带有 Bonferroni 校正的 Mann-Whitney 检验（alpha=.05）。
USPHS 评估显示，IPS e.max Press 和金属陶瓷牙冠的临床变化比 Procera AllCeram 少。Procera AllCeram 牙冠的咬合接触区出现明显的粗糙度、磨损和变形。SEM 图像显示两种陶瓷牙冠系统均有清晰定义的磨损面。Kruskal-Wallis 检验显示 3 种牙冠系统的 Alpha 评分存在显著差异（P<.05）。Mann-Whitney 检验显示各组之间存在显著差异。
根据改良的 USPHS 标准，IPS e.max Press 牙冠的临床行为与 Procera AllCeram 和金属陶瓷牙冠相当，但这种牙冠类型的耐磨性优于 Procera AllCeram 牙冠。
