Lezaja Maja, Veljovic Djordje N, Jokic Bojan M, Cvijovic-Alagic Ivana, Zrilic Milorad M, Miletic Vesna
School of Dental Medicine, University of Belgrade, Rankeova 4, 11000, Belgrade, Serbia.
J Biomed Mater Res B Appl Biomater. 2013 Nov;101(8):1469-76. doi: 10.1002/jbm.b.32967. Epub 2013 Jun 7.
This study investigated the effect of shape, size, and surface modification of hydroxyapatite (HAP) fillers on the degree of conversion (DC) and mechanical properties of a model BisGMA/TEGDMA composite initially and after 4 weeks of storage. Ten percent of conventional glass fillers were replaced by HAP spheres (Sph), silicon-doped spheres (SphSi), whiskers (Wh), silicon-doped whiskers (WhSi), and nanosized HAP particles (Nano). Spheres were specifically structured agglomerates consisting of a central void and radially orientated primary particles, whereas whiskers were compact monocrystals. DC, Vickers hardness (HV), flexural strength (Fs), flexural modulus (Ef), compressive strength (Cs), and compressive modulus (Ec) were tested. There were no significant differences in the DC between all tested groups. HV decreased by 5.4-17% with the addition of HAP, while Fs increased by 13.9-29% except in Nano group (decrease by 13%). After storage, Sph and SphSi groups showed similar HV, Ef, Cs and Ec and higher Fs than the control. The fracture mode of HAP spheres was through the central void whereas whiskers showed longitudinal delamination, transverse, and mixed fractures. HAP spheres with or without silicon- doping have a potential to be part of the filler content of dental composites.
本研究调查了羟基磷灰石（HAP）填料的形状、尺寸和表面改性对一种典型的双甲基丙烯酸缩水甘油酯/二缩三乙二醇二甲基丙烯酸酯（BisGMA/TEGDMA）复合材料初始以及储存4周后的转化率（DC）和力学性能的影响。用HAP球体（Sph）、硅掺杂球体（SphSi）、晶须（Wh）、硅掺杂晶须（WhSi）和纳米级HAP颗粒（Nano）替代10%的传统玻璃填料。球体是由中心空隙和径向排列的初级颗粒组成的特定结构团聚体，而晶须是致密的单晶。测试了DC、维氏硬度（HV）、弯曲强度（Fs）、弯曲模量（Ef）、压缩强度（Cs）和压缩模量（Ec）。所有测试组之间的DC没有显著差异。添加HAP后，HV下降了5.4 - 17%，而Fs除了Nano组（下降13%）外增加了13.9 - 29%。储存后，Sph和SphSi组显示出相似的HV、Ef、Cs和Ec，并且Fs高于对照组。HAP球体的断裂模式是通过中心空隙，而晶须显示出纵向分层、横向和混合断裂。有或没有硅掺杂的HAP球体有可能成为牙科复合材料填料成分的一部分。
