表面处理工艺对长石质牙科陶瓷摩擦学特性的影响

Effect of Surface Treatment on Friction and Wear Behavior of Dental Porcelain

通过体外模拟口腔环境,采用往复摩擦磨损试验机考察了经自身上釉、离子交换及机械打磨抛光等3种不同表面处理方式的长石质牙科陶瓷材料在人工唾液润滑下同纯钛对摩时的摩擦学特性,探讨了表面处理对牙科陶瓷材料显微硬度、断裂韧性、表面形貌和元素组成的影响.结果表明:牙科临床常用的表面处理工艺对牙科陶瓷摩擦系数的影响较小,经3种不同表面处理的陶瓷试样的摩擦系数仅在滑动初期存在一定差异;经离子交换处理的陶瓷试样的抗磨性能较优;长石质牙科陶瓷同纯钛对摩时,偶件钛向陶瓷试样磨损表面发生转移;牙科陶瓷材料的耐磨性能同力学性能的相关性不强,原因在于耐磨性能同微观结构等密切相关.

Dental porcelain VitaVMK95 was subjected to auto-glazing, surface ion exchanging and polishing, respectively. The effect of various surface treatments on the friction and wear behavior of the dental porcelain was investigated on a Deltalab-Nene reciprocal friction and wear test rig. Thus the plane specimens made of the surface-treated dental porcelain were made to slide against a pure titanium ball counterpart under the lubrication of a synthetic saliva. The wear scars of the dental porcelain specimens were observed with a co-focus laser-scanning microscope, and the elemental composition thereof was determined on an energy dispersive spectrometer. Moreover, the surface roughness, surface hardness, and fracture toughness of the dental porcelain specimens subjected to different surface treatments were measured so as to investigate the relationship between the tribological properties and mechanical properties. It was found that the dental porcelain specimens subjected to different surface treatments showed a little difference in the friction coefficient, i.e., the friction coefficient had a small difference at the early sliding-stage but assumed almost unchanged steady-state values. The dental porcelain after surface ion exchanging had better wear-resistance than the ones after auto glazing and polishing, and the later two showed almost the same wear-resistance. The friction and wear behaviors of the dental porcelain specimens subjected to different surface treatments were nearly independent on the surface roughness and surface hardness, because the friction and wear behaviors of various dental porcelain specimens were closely related to their microstructures. In addition, Ti was detected on the worn surface of the dental porcelain specimen by EDS, which indicated that the counterpart Ti transferred onto the surface of the dental porcelain specimen during the lubricated sliding.