Ruddell D E, Maloney M M, Thompson J Y
Curriculum in Applied and Materials Sciences, University of North Carolina, Chapel Hill, NC, USA.
Dent Mater. 2002 Jan;18(1):72-80. doi: 10.1016/s0109-5641(01)00022-7.
The purpose of this study was to investigate the method of producing pre-polymerized fused-fiber filler modified composite (PP-FFMC) particles and the effectiveness of incorporating these novel filler particles into dental composites.
Fused-fiber filler (FFF) blocks were impregnated with composite by two different methods. Three-point flexure tests were utilized to determine which was more effective. In order to assess the effect of the addition of PP-FFMC particles, two Bis-GMA/TEGDMA based conventional composite compositions were utilized as baselines, to which the novel particles were added. Mechanical and wear tests were performed to determine the fracture toughness, biaxial flexure strength, and in vitro wear of the materials.
Mechanical testing showed that the addition of PP-FFMC particles decreased the strength and toughness of the conventional composites. Wear tests indicated that addition of the same particles improved the wear behavior of the conventional composites. SEM analysis of the fracture surfaces indicated that the PP-FFMC particles were incorporated without creating porosity, and that fracture was transgranular through the reinforcing particles. Microscopic flaws observed in the novel particles are the likely explanation for the observed strength and toughness values.
The results indicate that PP-FFMC particles have the potential to improve the wear properties of dental composites, however, they adversely affect the fracture behavior. Existing processing techniques for these particles, which introduce imperfections, limit their current usefulness.
本研究旨在探究制备预聚合熔合纤维填料改性复合材料（PP - FFMC）颗粒的方法，以及将这些新型填料颗粒掺入牙科复合材料中的效果。
通过两种不同方法用复合材料浸渍熔合纤维填料（FFF）块体。利用三点弯曲试验来确定哪种方法更有效。为了评估添加PP - FFMC颗粒的效果，使用两种基于双酚A缩水甘油醚/三乙二醇二甲基丙烯酸酯的传统复合配方作为基线，并向其中添加新型颗粒。进行力学和磨损试验以确定材料的断裂韧性、双轴弯曲强度和体外磨损情况。
力学测试表明，添加PP - FFMC颗粒降低了传统复合材料的强度和韧性。磨损试验表明，添加相同颗粒改善了传统复合材料的磨损性能。断口表面的扫描电子显微镜分析表明，PP - FFMC颗粒掺入后未产生孔隙，且断裂是穿过增强颗粒的穿晶断裂。在新型颗粒中观察到的微观缺陷可能是所观察到的强度和韧性值的原因。
结果表明，PP - FFMC颗粒有改善牙科复合材料磨损性能的潜力，然而，它们对断裂行为有不利影响。这些颗粒现有的加工技术会引入缺陷，限制了它们目前的实用性。
