Aside from being known for its excellent mechanical properties and aesthetic effect, zirconia has recently attracted attention as a new dental implant material. Many studies have focused on hydroxyapatite (HA) coating for obtaining improved biocompatibility, however the coating stability was reduced by a byproduct produced during the high-temperature sintering process. In this study, to overcome this problem, we simply coated the zirconia surface with a sol–gel-derived hydroxyapatite (HA) layer and then sintered it at a varied temperature (<1000 °C). The surface showed a nanoporous structure, and there was no crystalline phase other than HA and zirconia when the sintering temperature was 800 °C. The adhesion strength of the HA layer (>40 MPa) was also appropriate as a dental implant application. In addition, in vitro cell experiments using a preosteoblast cell line revealed that the HA-coated zirconia surface acts as a preferable surface for cell attachment and proliferation than bare zirconia surface. In vivo animal experiments also demonstrated that the osteoconductivity of zirconia were dramatically enhanced by HA coating, which was comparable to that of Ti implant. These results suggest that the sol–gel-based HA-coated zirconia has a great potential for use as a dental implant material.

除了以其优异的机械性能和美学效果而闻名，氧化锆最近作为一种新的牙科植入材料引起了人们的关注。许多研究都集中在羟基磷灰石 (HA) 涂层上以获得更好的生物相容性，但是在高温烧结过程中产生的副产物降低了涂层的稳定性。在这项研究中，为了克服这个问题，我们简单地用溶胶-凝胶衍生的羟基磷灰石 (HA) 层涂覆氧化锆表面，然后在不同的温度 (<1000 °C) 下对其进行烧结。表面呈纳米多孔结构，烧结温度为800℃时，除HA和氧化锆外没有其他晶相。HA 层的粘合强度 (>40 MPa) 也适合作为牙种植体应用。此外，使用前成骨细胞系的体外细胞实验表明，与裸氧化锆表面相比，HA 涂层的氧化锆表面是细胞附着和增殖的优选表面。体内动物实验还表明，HA涂层显着增强了氧化锆的骨传导性，与Ti植入物相当。这些结果表明，基于溶胶-凝胶的 HA 涂层氧化锆具有作为牙科植入材料的巨大潜力。