劣化对氧化锆用饰面瓷表面粗糙度和化学组成及硬度的影响

Effects of aging on the surface roughness,composition and hardness of veneering ceramics for zirconia frameworks

目的目前有关饰面瓷劣化研究较少。文中旨在评价加速劣化对氧化锆用饰面瓷表面的粗糙度、化学组成及硬度的影响。方法选择5种氧化锆用饰面瓷ZR、CZR、VM9、KISS及e.max。每种饰面瓷各制作20个实验试件,并被随机分成2组:劣化组(进行加速劣化实验)、对照组(未进行加速劣化实验),每组10个。加速劣化条件是200℃,2个大气压,维持5h。使用激光共聚焦扫描轮廓仪和维氏硬度仪测定表面粗糙度(Ra、Rp、Rv、RSm)和维氏硬度。通过扫描电镜和能量色散谱仪评价表面形貌特征和表面化学组成。结果与饰面瓷ZR的对照组Ra[(0.157±0.009)μm],Rp[(0.356±0.031)μm]和Rv[(0.411±0.034)μm]比较,劣化组[(0.197±0.008)、(0.446±0.036)、(0.498±0.036)μm]显著升高(P=0.000),饰面瓷CZR、VM9、KISS劣化组亦明显升高(P=0.000)。饰面瓷CZR劣化组Ra,Rp和Rv参数值比饰面瓷ZR、VM9、KISS、e.max更高(P<0.001)。饰面瓷e.max劣化组Ra,Rp和Rv参数值较饰面瓷ZR、CZR、VM9、KISS更低(P<0.01)。所有饰面瓷的劣化组RSm值均较对照组显著降低(P<0.001)。所有饰面瓷劣化组氧含量显著高于对照组(P<0.05),钾和钠含量显著低于对照组(P<0.05)。与饰面瓷ZR,KISS和e.max对照组硅含量比较,劣化组明显减少(P<0.01)。饰面瓷ZR和VM9劣化组钙含量较对照组明显减少(P<0.05)。饰面瓷ZR劣化组维氏硬度显著地低于对照组[(5.01±0.28) vs (6.91±0.51) GPa],差异有统计学意义(P=0.000),其他饰面瓷亦显著地低于对照组(P=0.000)。结论加速劣化使不同种类氧化锆用饰面瓷表面性状发生显著改变,降低修复体稳定性和使用寿命,为口腔修复提供了依据。

Objective Few studies are reported on the aging of veneering ceramics.This study was to investigate the effects of aging on surface roughness,composition and hardness of veneering ceramics for zirconia frameworks.Methods Twenty specimens were fabricated with each of the five types of veneering ceramics for zirconia frameworks-Vintage ZR(ZR),Cerabien ZR(CZR),VitaVM9(VM9),Cercon ceram KISS(KISS)and IPS e.max ceram(e.max).The specimens were randomly divided into an aging and a control group of equal number,the former subjected to accelerated aging at 200℃and 2 atm for 5 hours while the latter left untreated.The surface roughness and Vickers hardness of the specimens were measured using laser profilometry and Vicker's indentation test machine and their surface topography and chemical composition examined by scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).Results Compared with the control group,the aged specimens fabricated with ZR showed significantly increased surface roughness parameters Ra([0.157±0.009]vs[0.197±0.008]μm,P=0.000),Rp([0.356±0.031]vs[0.446±0.036]μm,P=0.000)and Rv([0.411±0.034]vs[0.498±0.036]μm,P=0.000),and so did those fabricated with CZR,VM9 and KISS(P=0.000).The Ra,Rp and Rv parameter values of the aged specimens with CZR were remarkably higher than those with VM9,KISS and e.max(P<0.001),but those of the aged specimens with e.max markedly lower than those with ZR,CZR,VM9 and KISS(P<0.01).The RSm value was significantly higher in all the aged specimens than in the control(P<0.001),and so was the oxygen content(P<0.05),but the levels of sodium and potassium were lower in the former than in the latter group(P<0.05).Compared with the control group,the silicon content was significantly decreased in the aged specimens with ZR,KISS and e.max(P<0.01),and so was that of calcium in those with ZR and VM9(P<0.05).The Vickers hardness of the aged specimens with ZR was remarkably lower than that of the control([5.01±0.28]vs[6.91±0.51]GPa,P=0.000),and so was that of the other aged specemens(P=0.000).Conclusion Accelerated aging can significantly alter the surface properties,enhance the stability and prolong the working life of veneering ceramics for zirconia frameworks.