University of Erlangen-Nuremberg, 91054 Erlangen, Germany.
J Prosthet Dent. 2010 Jan;103(1):40-4. doi: 10.1016/S0022-3913(09)60214-6.
Current copy-milling systems allow for the fabrication of 1-piece zirconia ceramic posts and cores, which can be used in combination with ceramic crowns to restore endodontically treated teeth in an esthetic manner. However, limited data are available on the fracture resistance of copy-milled zirconia ceramic posts.
The purpose of this in vitro study was to compare the fracture resistance of prefabricated posts made from zirconia ceramic and fiber-reinforced composite resin with the fracture resistance of copy-milled zirconia ceramic posts.
Three groups of posts and cores were fabricated (n=10): prefabricated zirconia ceramic posts with composite resin cores (ZIR), fiber-reinforced composite resin posts with composite resin cores (FRC), and copy-milled zirconia ceramic posts and cores (CM). Following artificial aging by thermal cycling and masticatory simulation, compressive tests were performed in a universal testing machine with the posts mounted at an angle of 135 degrees to the long axis of the posts. The maximum forces needed to fracture the posts were recorded for statistical analysis (1-way ANOVA, Tukey's Honestly Significant Difference test; alpha=.05).
The mean maximum forces (SD) needed to fracture the posts and cores were 123.10 (19.38) N for FRC, 139.30 (42.70) N for CM, and 267.10 (59.11) N for ZIR. The prefabricated zirconia ceramic posts required significantly higher fracture loads as compared to FRC (P<.001) and CM (P<.001).
The fracture load of copy-milled zirconia ceramic posts is significantly lower than that of prefabricated zirconia ceramic posts of the same size.
目前的复制铣削系统允许制造 1 件氧化锆陶瓷桩核，可与陶瓷冠结合，以美观的方式修复根管治疗后的牙齿。然而，关于复制铣削氧化锆陶瓷桩的抗折强度的数据有限。
本体外研究的目的是比较预成型氧化锆陶瓷桩和纤维增强复合树脂制成的桩与复制铣削氧化锆陶瓷桩的抗折强度。
制作了三组桩核（n=10）：氧化锆陶瓷桩复合树脂核（ZIR）、纤维增强复合树脂桩复合树脂核（FRC）和复制铣削氧化锆陶瓷桩核（CM）。经过热循环和咀嚼模拟人工老化后，将桩以 135 度角安装在万能试验机上进行压缩试验。记录断裂时所需的最大力，进行统计分析（单向方差分析，Tukey Honestly Significant Difference 检验；α=.05）。
断裂桩核所需的平均最大力（SD）分别为 FRC 组 123.10（19.38）N、CM 组 139.30（42.70）N 和 ZIR 组 267.10（59.11）N。预制氧化锆陶瓷桩所需的断裂负荷明显高于 FRC（P<.001）和 CM（P<.001）。
复制铣削氧化锆陶瓷桩的断裂负荷明显低于相同尺寸的预制氧化锆陶瓷桩。
