Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
Department of Physics, Faculty of Science, Anadolu University, Eskişehir, Turkey.
J Adv Prosthodont. 2014 Jun;6(3):224-32. doi: 10.4047/jap.2014.6.3.224. Epub 2014 Jun 24.
The purpose of the present study was to evaluate the effect of thermocycling and mechanical loading on the biaxial flexural strength and the phase transformation of one Ce-TZP/Al2O3 and two Y-TZP core materials.
Thirty disc-shaped specimens were obtained from each material. The specimens were randomly divided into three groups (control, thermocycled, and mechanically loaded). Thermocycling was subjected in distilled water for 10000 cycles. Mechanical loading was subjected with 200 N loads at a frequency of 2 Hz for 100000 times. The mean biaxial flexural strength and phase transformation of the specimens were tested. The Weibull modulus, characteristic strength, 10%, 5% and 1% probabilities of failure were calculated using the biaxial flexural strength data.
The characteristic strengths of Ce-TZP/Al2O3 specimens were significantly higher in all groups compared with the other tested materials (P<.001). Statistical results of X-ray diffraction showed that thermocycling and mechanical loading did not affect the monoclinic phase content of the materials. According to Raman spectroscopy results, at the same point and the same material, mechanical loading significantly affected the phase fraction of all materials (P<.05).
It was concluded that thermocycling and mechanical loading did not show negative effect on the mean biaxial strength of the tested materials.
本研究旨在评估热循环和机械加载对 1 种 Ce-TZP/Al2O3 和 2 种 Y-TZP 核材料的双轴弯曲强度和相转变的影响。
从每种材料中获得 30 个圆盘形试件。试件随机分为 3 组（对照组、热循环组和机械加载组）。将热循环在蒸馏水中进行 10000 次循环。机械加载在频率为 2Hz 的 200N 负载下进行 100000 次。测试了试件的平均双轴弯曲强度和相转变。使用双轴弯曲强度数据计算了威布尔模量、特征强度、10%、5%和 1%失效概率。
Ce-TZP/Al2O3 试件的特征强度在所有组中均明显高于其他测试材料（P<.001）。X 射线衍射的统计结果表明，热循环和机械加载对材料的单斜相含量没有影响。根据拉曼光谱结果，在相同的点和相同的材料下，机械加载显著影响所有材料的相分数（P<.05）。
热循环和机械加载对测试材料的平均双轴强度没有显示出负面影响。
