FUSED FIBER NETWORKS FOR TOUGHENED DENTAL COMPOSITES

代汞材料的开发是一项高科技研究 由于与汞有关的环境问题而被列为优先事项 管理 牙科复合材料有可能成为替代材料 在可预见的未来， 其他替代材料 (e.g.,陶瓷）过于复杂和昂贵。 目前使用 然而，直接放置的牙科复合材料在某种程度上受到限制， 聚合收缩过大，断裂磨损不良 阻力 这些特征可能导致微渗漏 和继发龋的发展，并降低预期寿命 在承载应用中的复合材料应用。 因为 根据这些因素，目前的牙科复合材料仅推荐用于 保守的应用。 使用新型填料是一种方法， 扩大现有牙科器械的应用范围 复合技术 三维“支架状”填充物已被 在有限的研究中对各种牙科材料进行了研究， 结果好坏参半。 拟议研究的总体目标是 测试“支架样”熔融纤维的结合 填充剂将减少牙科复合材料的收缩， 抗断裂性，对复合材料磨损无不良影响 标准牙科复合材料组合物的耐受性。 具体目标 建议的研究是：（1）确定添加剂的效果 预聚合的熔融纤维填料颗粒占总体积的 标准牙科复合材料组合物的收缩率，（2）测定 添加预聚合的熔融纤维填料颗粒对 标准牙体弯曲强度和断裂韧性 复合材料组成，（3）确定添加的效果， 预聚熔融纤维填料颗粒对体外磨损的影响 标准牙科复合材料组合物的性能，和（4）确定 如果断裂韧性和磨损率之间存在任何相关性， 改性和未改性的牙科复合材料组合物。 体积 使用比重技术测量收缩率。 骨折 韧性将由受控的裂纹断裂强度决定 二次起爆技术及断口分析 缺点将使用改良的Leinfelder磨损试验模拟磨损 仪器并使用标准轮廓测定技术测量。在 此外，SEM和AFM将用于表征预聚物 熔融纤维填料颗粒和改性的复合材料微观结构。

The development of amalgam-substitute materials is a high research priority due to environmental concerns associated with mercury management. Dental composites are likely to be the substitute material of choice for the foreseeable future. Other alternative materials (e.g., ceramics) are excessively complex and expensive. Current use of directly placed dental composites is somewhat limited, however, due to excessive polymerization shrinkage and inferior fracture and wear resistance. These characteristics can potentially lead to microleakage and the development of secondary caries, and reduce the life expectancy of composite restorations in load bearing applications. Because of these factors, current dental composites are recommended only for conservative applications. The use of novel fillers is one approach to expand the range of applications for currently available dental composite technology. Three-dimensional "scaffold-like" filler has been investigated in a variety of dental materials in limited studies with mixed results. The overall objective of the proposed research is to test the hypothesis that incorporation of a "scaffold-like" fused-fiber filler will decrease dental composite shrinkage, increase composite fracture resistance, and produce no adverse effects on composite wear resistance of standard dental composite compositions. The specific aims of the proposed research are to: (1) determine the effect of additions of prepolymerized fused-fiber filler particles on the overall volumetric shrinkage of standard dental composite compositions, (2) determine the effect of additions of prepolymerized fused-fiber filler particles on the flexural strength and fracture toughness of standard dental composite compositions, (3) determine the effect of additions of prepolymerized fused-fiber filler particles on the in vitro wear behavior of standard dental composite compositions, and (4) determine if there is any correlation between the fracture toughness and wear rate of modified and unmodified dental composite compositions. Volumetric shrinkage will be measured using specific gravity techniques. Fracture toughness will be determined by a controlled flaw fracture strength technique and through fractographic evaluation of fracture-initiating flaws. Wear will be simulated using a modified Leinfelder wear testing apparatus and measured using standard profilometric techniques. In addition, SEM and AFM will be used to characterize the prepolymerized fused-fiber filler particles and the modified composite microstructures.