Ha Na Ra, Yang Zheng Xun, Hwang Kyu Hong, Kim Tae Suk, Lee Jong Kook
Engineering Res. Institute, i-Cube Center, Gyeongsang Nat'l University, Jinju 660-701, S. Korea.
J Nanosci Nanotechnol. 2010 May;10(5):3459-62. doi: 10.1166/jnn.2010.2342.
Hydroxyapatite has achieved significant application in orthopedic and dental implants due to its excellent biocompatibility. Sintered hydroxyapatites showed significant dissolution, however, after their immersion in water or simulated body fluid (SBF). This grain boundary dissolution, even in pure hydroxyapatites, resulted in grain separation at the surfaces, and finally, in fracture. In this study, hydroxyapatite ceramics containing apatite-wollastonite (AW) or calcium silicate (SG) glass ceramics as additives were prepared to prevent the dissolution. AW and SG glass ceramics were added at 0-7 wt% and powder-compacted uniaxially followed by firing at moisture conditions. The glass phase was incorporated into the hydroxyapatite to act as a sintering aid, followed by crystallization, to improve the mechanical properties without reducing the biocompatibility. As seen in the results of the dissolution test, a significant amount of damage was reduced even after more than 14 days. TEM and SEM showed no decomposition of HA to the secondary phase, and the fracture toughness increased, becoming even higher than that of the commercial hydroxyapatite.
由于具有优异的生物相容性，羟基磷灰石在骨科和牙科植入物中已得到广泛应用。然而，烧结羟基磷灰石在浸入水或模拟体液（SBF）后会出现明显溶解。即使是纯羟基磷灰石，这种晶界溶解也会导致表面晶粒分离，最终导致断裂。在本研究中，制备了含有磷灰石-硅灰石（AW）或硅酸钙（SG）玻璃陶瓷作为添加剂的羟基磷灰石陶瓷，以防止溶解。AW和SG玻璃陶瓷的添加量为0-7 wt%，通过单轴粉末压制，然后在潮湿条件下烧制。玻璃相被引入羟基磷灰石中作为烧结助剂，随后进行结晶，以在不降低生物相容性的情况下改善机械性能。从溶解试验结果可以看出，即使经过14天以上，大量损伤也有所减少。透射电子显微镜（TEM）和扫描电子显微镜（SEM）显示羟基磷灰石没有分解为次生相，断裂韧性增加，甚至高于商业羟基磷灰石。
