Studies on Deterioration Process of Dental Materials

利用三体磨损试验机研究了填料种类和含量对树脂基复合材料耐磨性的影响。采用无机填料、树脂单体(Bis-GMA/TEGDMA)、光引发剂、促进剂和阻聚剂制备了光固化树脂复合材料。采用五种填料(石英，Q；无定形二氧化硅，AM；钡玻璃，Ba；锶玻璃，锶；微细二氧化硅，MF)作为无机相。对于每一种树脂复合材料，尽量使填料的粒度分布相同。填料平均粒径在3.01m左右，另外两种复合材料中分别加入20wt%和40wt%的微细二氧化硅填料。使用阿拉巴马州磨损模拟器进行了体外磨损试验。磨损试验后，用3D-LaserScanner测量磨损量。结果表明，当填料质量分数分别为40wt%、60wt%和70wt%时，Am、Ba或Sr、Q的磨损量最大。不同填料含量的复合材料中，Am和Ba基复合材料的力学性能有显著差异，而Q基和锶基复合材料的差异不明显。其次，当填充量大于60wt%时，AM填充的复合材料耐磨性最好，其次是BaO和Q填充的复合材料。含锶复合材料表现出最大的EAR量，而与填料含量无关。在填料负载量小于40wt%时，微填充材料在这两种情况下的磨损量都显着降低。在60wt%的常规树脂复合材料(杂化)中添加20wt%的微填料可提高所有类型的填料的抗耳性。通过混合填充体系，可以达到与微填充复合材料相同的磨损水平。结果表明，填料的大小、种类和含量对树脂基复合材料的耐磨性有影响。

The purpose of this study is to investigate the effects of filler type and filler content on the wear resistance of resin composites using a three-body wear testing machine. Experimental light-cured resin composites were fabricated with inorganic fillers, resin monomers (Bis-GMA/TEGDMA), photo-initiator, accelerator and inhibitor. Five kinds of fillers (Quartz, Q; Amorphous silica, Am; Barium glass, Ba; Strontium glass, Sr; Microfine silica, MF) were used as inorganic phase. For every resin composites, the filler size distribution was tried to be the same as much a possible. Mean filler size was around 3.0 i m. In addition, two additional composites were filled with 20wt% and 40wt% microfine silica fillers. The in vitro wear testing was carried out using the Alabama wear simulator. After wear testing, the amount of wear was measured with 3D-laserscanner. As a result, Am, Ba or Sr and Q showed the maximum wear loss when the filler content was 40, 60 and 70 wt %, respectively. Am- and Ba-loaded composites showed a significant difference among the composites with different filler content, while no difference was found with Q- and Sr- loaded ones. Next, when more than 60 wt% of fillers are loaded in matrix resin, Am-loaded composites showed the most wear resistance, then followed by Ba- and Q-loaded ones. Sr-containing composites exhibited the largest amount of ear irrespective of filler content. At a filler load less than 40 wt% the microfilled materials had in both cases a significantly reduced amount of wear. Addition of 20 wt% microfillers to 60 wt% conventional resin composites (hybridization) increased the ear resistance for all filler types. The same level of wear as with microfilled composites is reached by hybridization of the filler system. It could be concluded from these results that size, type and content of fillers influence the wear resistance of resin composites.