El Zhawi Haifa, Kaizer Marina R, Chughtai Asima, Moraes Rafael R, Zhang Yu
Department of Biomaterials and Biomimetics, New York University College of Dentistry, 433 First Avenue, New York, NY 10010, USA.
Department of Biomaterials and Biomimetics, New York University College of Dentistry, 433 First Avenue, New York, NY 10010, USA; School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil.
Dent Mater. 2016 Nov;32(11):1352-1361. doi: 10.1016/j.dental.2016.08.216. Epub 2016 Aug 29.
To investigate fatigue fracture resistance and wear behavior of a polymer infiltrated ceramic network (PICN) material (ENAMIC, Vita Zahnfabrik).
Anatomically shaped ENAMIC monolithic crowns were milled using a CAD/CAM system. The crowns were cemented on aged dentin-like composite abutments (Z100, 3M ESPE) with resin-based cement (Vita DUO Cement, Vita). The specimens were subjected to 2 types of fatigue and wear tests: (1) accelerated sliding-contact mouth-motion step-stress fatigue test (n=24) in water; and (2) long-term sliding-contact mouth-motion fatigue/wear test using a clinically relevant load (P=200N, n=8) in water. Failure was designated as chip-off or bulk fracture. Optical and scanning electron microscopes were used to examine the occlusal surface and subsurface damage, as well as to reveal the material's microstructure. In addition, wear volume and depth were measured by X-ray micro-computed tomography.
For accelerated mouth-motion step-stress fatigue testing, 3 out of the 24 ENAMIC crowns fractured following cyclic loading up to 1700N. Minor occlusal damage and contact-induced cone cracks were observed in all surviving specimens, but no flexural radial cracks were seen. For long-term mouth-motion fatigue/wear testing under a 200N load in water, a small wear scar without significant cracks was observed in all 8 tested ENAMIC crowns.
Monolithic CAD/CAM ENAMIC crowns showed superior resistance to sliding-contact fatigue fracture and wear.
研究聚合物渗透陶瓷网络（PICN）材料（ENAMIC，维他齿科）的抗疲劳断裂性能和磨损行为。
使用CAD/CAM系统铣削出解剖形状的ENAMIC整体冠。用树脂基水门汀（Vita DUO Cement，维他）将冠粘固在老化的类牙本质复合基台上（Z100，3M ESPE）。对试件进行两种类型的疲劳和磨损试验：（1）在水中进行加速滑动接触口腔运动阶梯应力疲劳试验（n = 24）；（2）在水中使用临床相关载荷（P = 200N，n = 8）进行长期滑动接触口腔运动疲劳/磨损试验。失效定义为崩裂或整体断裂。使用光学显微镜和扫描电子显微镜检查咬合面和亚表面损伤，以及揭示材料的微观结构。此外，通过X射线微计算机断层扫描测量磨损体积和深度。
对于加速口腔运动阶梯应力疲劳试验，24个ENAMIC冠中有3个在循环加载至1700N后发生断裂。在所有存活的试件中均观察到轻微的咬合损伤和接触诱导的锥形裂纹，但未见弯曲径向裂纹。对于在水中200N载荷下的长期口腔运动疲劳/磨损试验，在所有8个测试的ENAMIC冠中均观察到一个小的磨损疤痕，无明显裂纹。
CAD/CAM整体ENAMIC冠显示出优异的抗滑动接触疲劳断裂和磨损性能。
