Adatia Nimet D, Bayne Stephen C, Cooper Lyndon F, Thompson Jeffery Y
University of North Carolina School of Dentistry, Chapel Hill, NC, USA.
J Prosthodont. 2009 Jan;18(1):17-22. doi: 10.1111/j.1532-849X.2008.00378.x.
An in vitro study was performed to assess the effect of different degrees of clinical reduction of zirconia abutments on the failure load of clinical assemblies.
Zirconia abutments (Y-TZP Ceramic Abutment, Astra Tech) were prepared with 0, 0.5, or 1 mm of external axial reduction starting 1 mm above the height-of-contour. Abutments (n = 10) were attached to implant analogs (25 Ncm torque) embedded in a stainless steel cylinder using Field's metal. Fracture loads (N) were determined when assemblies were loaded at 60 degrees off-axis until failure (Instron, CHS = 0.1 mm/min). Groups were statistically compared using ANOVA (p < 0.05).
Fracture loads for all assemblies displayed large variations within groups. There were no statistically significant differences (p > 0.05) among different abutment groups with a mean fracture load of 429 N (+/-140) for the control group, 576 N (+/-120) for 0.5-mm margins, and 547 (+/-139) for 1.0-mm margins. All fractures occurred at the interface where the abutment was connected to the analog.
In this in vitro study of simulated ultimate assembly strength, the preparation of zirconia abutments did not significantly impair the fracture resistance of simulated implant assemblies. All implant abutments fractured at rates higher than the maximum incisal forces (90-370 N) estimated to occur in the anterior region of the mouth.
进行一项体外研究，以评估氧化锆基台不同程度的临床就位对临床组件破坏载荷的影响。
制备氧化锆基台（Y-TZP陶瓷基台，Astra Tech），从外形高点上方1mm处开始进行0、0.5或1mm的外部轴向就位。使用菲尔德合金将基台（n = 10）连接到嵌入不锈钢圆柱体中的种植体代型上（扭矩为25 Ncm）。当组件以离轴60度加载直至破坏时测定破坏载荷（N）（Instron，CHS = 0.1 mm/min）。使用方差分析对各组进行统计学比较（p < 0.05）。
所有组件的破坏载荷在组内显示出很大差异。不同基台组之间无统计学显著差异（p > 0.05），对照组的平均破坏载荷为429 N（±140），0.5mm边缘组为576 N（±120），1.0mm边缘组为547（±139）。所有骨折均发生在基台与代型连接的界面处。
在这项模拟最终组件强度的体外研究中，氧化锆基台的制备并未显著损害模拟种植体组件的抗断裂性。所有种植体基台的断裂发生率均高于估计在口腔前部区域出现的最大切牙力（90 - 370 N）。
