水域环境下牙科饰面烤瓷强度的测定和Weibull统计分析

Determination and Weibull Analysis of the Strength of Dental Veneering Porcelains

目的从断裂概率角度研究牙科烤瓷在水域环境下强度的分散性,分析其材料质地的均匀程度,为牙科烤瓷的强度可靠性评价和进一步的疲劳分析提供参考。方法分别采用SHOFUVintage体瓷、切端瓷、透明瓷制作瓷条,打磨加工成2mm×3mm×20mm标准试件,置烘箱中70℃干燥24h后置37℃人工唾液中浸泡30d备用。随机选取经人工唾液浸泡的20件试件在0.5mm/min加载速率下测试三点弯曲强度。用二参数Weibull法对数据进行分析。结果体瓷、切端瓷、透明瓷在人工唾液中浸泡30d后的强度分别是:(75.5±5.6)MPa,(73.6±5.0)MPa,(72.9±4.5)MPa。在人工唾液的Weibull模数(m)和特征强度(σ0)分别是:m=17.3,σ0=77.6MPa;m=16.5,σ0=76.0Mpa;m=16.1,σ0=75.5MPa。结论三种烤瓷材料在水域浸泡后的强度、Weibull模数和特征强度接近。Weibull分析相对单纯平均强度和标准差而言,更加充分地描述了材料在人工唾液环境中的强度特性。

Objective To determine the strength of the veneering porcelain stored in artificial saliva. Methods Standard beams with a size of 3 mm × 2 mm ×20 mm made from the body, ineisal, and translucent porcelains of SHOFU Vintage were stored in the artificial saliva for 30 days. Twenty samples from each material were tested for the strength by the 3-point flexural test at a erosshead speed of 0.5 ram. The data were analyzed by the two-parameter Weibull method. Results The strength, Weibull modulus （m） and characterization strength （σ0） were （75.5±5.6） MPa, 17.3, and 77.6 MPa for Body porcelain, respectively; （73.6±5. 0） MPa, 16. 5, and 76. 0 MPa for incisal porcelain, respectively; and （72. 9±4. 5） MPa, 16. 1, and 75. 5 MPa for translucent porcelain, respectively. Conclusion There are no differences in strength between the three dental porcelains. Weibull analysis describes the strength of the porcelains better than the average and standard deviation.