Department of Prosthodontics, Dental School, University Clinics of Freiburg, Freiburg, Germany.
Clin Oral Implants Res. 2011 Aug;22(8):808-14. doi: 10.1111/j.1600-0501.2010.02067.x. Epub 2011 Feb 15.
Zirconia is a potential material for the fabrication of oral implants. The aim of this study was to evaluate the effects of cyclic loading and preparation on the fracture strength of a zirconia implant system.
Forty-eight one-piece implants were divided into two groups of 24 implants: group A (without modification) and group B (1 mm chamfer preparation). Groups A and B were divided into three subgroups of eight implants each (1 = no artificial load, 2 = artificial load [98 N; 1.2 million loading cycles], and 3 = artificial load [98 N; 5 million loading cycles]). After completion of the loading, the fracture strength of each implant was determined in a universal testing machine. A two-way analysis of variance was used, the continuous response variable (fracture strength in Newtons) is modeled as a function of preparation, cycles, and the corresponding interaction as explanatory variables.
The mean fracture strength values obtained for the groups were: A1 (no preparation, no load) = 1928.73 N, A2 (no preparation, 1.2 million cycles) = 2044.84 N, A3 (no preparation, 5 million cycles) = 1364.50 N, B1 (preparation, no load) = 1221.66 N, B2 (preparation, 1.2 million cycles) = 967.11 N, and B3 (preparation, 5 million cycles) = 884.89 N. Fracture values were significantly different between subgroups A1 vs. A3 and B1 vs. B3. There was no significant difference between subgroups A1 vs. A2 and B1 vs. B2.
Preparation as well as cyclic loading can decrease the fracture strength resistance of zirconia implants. Nevertheless, even the lowest values of mean fracture strength of the implants used in our study seem to withstand average occlusal forces even after an extended interval of artificial loading.
氧化锆是口腔种植体制造的一种潜在材料。本研究的目的是评估循环加载和制备对氧化锆种植体系统断裂强度的影响。
将 48 个整体式种植体分为两组，每组 24 个种植体：组 A（未经修饰）和组 B（1 毫米倒角制备）。组 A 和 B 又分为三组，每组 8 个种植体：1 = 无人工负载，2 = 人工负载[98 N；120 万次加载循环]，3 = 人工负载[98 N；500 万次加载循环]。完成加载后，在万能试验机上测定每个种植体的断裂强度。采用双因素方差分析，连续响应变量（牛顿的断裂强度）作为函数建模，解释变量为制备、循环和相应的相互作用。
各组获得的平均断裂强度值为：A1（无准备，无负载）= 1928.73 N，A2（无准备，120 万次循环）= 2044.84 N，A3（无准备，500 万次循环）= 1364.50 N，B1（准备，无负载）= 1221.66 N，B2（准备，120 万次循环）= 967.11 N，B3（准备，500 万次循环）= 884.89 N。亚组 A1 与 A3 和 B1 与 B3 之间的骨折值有显著差异。亚组 A1 与 A2 和 B1 与 B2 之间无显著差异。
制备以及循环加载会降低氧化锆种植体的断裂强度。然而，即使是我们研究中使用的种植体的最低平均断裂强度值，似乎也能承受平均咬合力，即使在延长的人工加载间隔后也是如此。
