Vallittu P K, Alakuijala P, Lassila V P, Lappalainen R
Faculty of Dentistry, University of Kuopio, Finland.
J Prosthet Dent. 1994 Sep;72(3):289-95. doi: 10.1016/0022-3913(94)90342-5.
In this study the fatigue life of heat-cured acrylic resin test specimens shaped as maxillary partial dentures was examined. Ten test specimens were prepared from polymethyl methacrylate and were tested by a constant force fatigue test at 150 N immersed in +37 degrees C water. The fatigue-fracture surfaces of the test specimens were compared with a one-bend fracture surface of the control specimen by scanning electron microscopy. The correlation coefficient between the number of loading cycles required to cause fatigue failure in the midline section was calculated as was the concentration of residual methyl methacrylate. Results revealed that the fatigue life of the test specimens varied greatly (483 x 10(3) +/- 371 x 10(3) cycles) and that the correlation between the number of loading cycles and the midline section was poor (r -0.455). The correlation coefficient between the number of loading cycles and the concentration of residual methyl methacrylate was r 0.476 and p > 0.5. The fatigue-fracture surface of the test specimens was smoother in texture on the tension side than on the one-bend fracture surface.
在本研究中，对制成上颌局部义齿形状的热固化丙烯酸树脂测试样本的疲劳寿命进行了检测。用聚甲基丙烯酸甲酯制备了10个测试样本，并在150牛的恒定力作用下，于37摄氏度的水中进行疲劳测试。通过扫描电子显微镜将测试样本的疲劳断裂表面与对照样本的一次弯曲断裂表面进行比较。计算了导致中线部分疲劳失效所需加载循环次数之间的相关系数以及残余甲基丙烯酸甲酯的浓度。结果显示，测试样本的疲劳寿命差异很大（483×10³±371×10³次循环），并且加载循环次数与中线部分之间的相关性较差（r = -0.455）。加载循环次数与残余甲基丙烯酸甲酯浓度之间的相关系数为r = 0.476，p＞0.5。测试样本的疲劳断裂表面在拉伸侧的质地比一次弯曲断裂表面更光滑。
