Petersen Richard C, Reddy Michael S, Liu Perng-Ru
Biomaterials and Restorative Sciences, School of Dentistry, University of Alabama at Birmingham, United States of America.
Office of the Dean, School of Dentistry, University of Alabama at Birmingham, United States of America.
EC Dent Sci. 2018 May;17(5):430-459. Epub 2018 Apr 10.
Newer dental fiber-reinforced composites can provide service with less wear than enamel. Further, fibers in bulk molding form pack oriented parallel to the occlusal-dentinal floor planes that wear by uniform thinning into micrometer-sized fiber remnants and subsequent flat plate-like particulate bond by compression back into the polymer matrix. The fiber wear-in process is accomplished by creating fine crystalline chemically resistant nanoparticulates that become an exceptional polishing agent. Resulting consolidation by the underlying fiber network squeezes plasticized polymer and partially hydrolyzed polymer chains along with residual monomer, pendant methacrylate groups and nano-sized particulate to the surface that surround larger exposed micrometer-sized particulate and smallest fiber remnants. Eventually consolidation of the polymer matrix overall squeezes up and engulfs the top particulate or fiber remnants forming a smooth polished hard polymer-matrix composite wear surface probably filled with small nanoparticulate. The final hardened polymer surface may show particulate from worn fibers, but displays no signs of the original fibers after an wear simulator test comparable to 3 years of clinical service. Nanoparticulates formed from the fibers that have broken down generally reconsolidate back in to the top surface for a polished toughened polymer surface or behave as a polishing agent. The underlying fiber-reinforced composite network supports wear loads to greatly reduce wear especially as fibers extend well beyond a critical length that prevents fiber debonding from the matrix. Further, fiber-reinforced composite consolidation can aid in cavity molding placement by applied pressure to squeeze monomer, resin and particulates from the fiber network toward collapsing or filling in voids and removing entrapped air.
新型牙科纤维增强复合材料的磨损比牙釉质少，能提供更好的服务。此外，整体模塑成型的纤维沿咬合面 - 牙本质层面平行排列，磨损时均匀变薄成为微米级的纤维残余物，随后通过压缩重新结合到聚合物基体中形成平板状颗粒粘结。纤维磨损过程中会形成耐化学腐蚀的精细晶体纳米颗粒，成为一种特殊的抛光剂。底层纤维网络导致的固结将增塑聚合物、部分水解的聚合物链以及残余单体、甲基丙烯酸酯侧基和纳米级颗粒挤压到表面，围绕着更大的暴露微米级颗粒和最小的纤维残余物。最终，聚合物基体的整体固结将顶部颗粒或纤维残余物挤压并吞没，形成一个光滑、抛光的硬质聚合物基体复合材料磨损表面，可能充满了小纳米颗粒。在经过相当于3年临床服务的磨损模拟器测试后，最终硬化的聚合物表面可能会显示出磨损纤维的颗粒，但没有原始纤维的迹象。由分解的纤维形成的纳米颗粒通常会重新固结到顶面，形成抛光的增韧聚合物表面，或起到抛光剂的作用。底层纤维增强复合材料网络支撑磨损载荷，能极大地减少磨损，尤其是当纤维延伸长度远超防止纤维从基体脱粘的临界长度时。此外，纤维增强复合材料的固结可以通过施加压力将单体、树脂和颗粒从纤维网络挤压到塌陷或填充空隙并去除 entrapped air，从而有助于腔模成型。 （注：原文中“entrapped air”直译为“被困空气”，结合语境这里可理解为“ entrapped air”表述有误，可能是“entrapped air bubble”即“ entrapped air bubble”，意为“截留气泡”，但按照要求不添加解释，故保留原文表述。）
