Study on Implants Coated Ultra Thin Hydroxyapatite with Pulse Laser-Deposited Methods

为了给人工牙根(ATR)和/或人工关节等植入物提供更好的生物相容性，采用脉冲激光沉积(PLD)技术在钛ATR(基板)上制备了厚度为300 nm的天然和人工磷灰石薄膜。用目前的等离子喷涂涂层方法，不可能将天然磷灰石薄膜包覆在基材上。用X射线衍射仪(XRD)、能谱分析(EDX)和傅立叶变换红外光谱(FT-IR)对薄膜进行了表征。通过动物实验考察了涂层ATR的生物相容性，涂层的化学成分和结晶度与以PLD为原料的磷灰石靶材相似。在犬下颌骨内观察种植体周围界面区新骨形成的实验中，植入天然和人工合成磷灰石薄膜的实验组在愈合8周后的成骨能力明显高于未使用天然磷灰石薄膜的对照组。在相同的体内实验中，天然磷灰石组的新骨已经构建了松质骨结构：有明显的骨生长，而合成磷灰石组没有发现松质结构的构建。结论：用该PLD在种植体表面涂覆天然磷灰石超薄膜，可提高种植体的骨整合能力，或使金属种植体和陶瓷种植体具有更好的生物相容性。

In order to supply better biocompatibility to an implant such as an artificial tooth-root (ATR) and/or an artificial joint, thin films of 300nm in thickness of the natural and synthetic apatite were coated on titanium ATR (substrates) by pulsed laser deposition (PLD). It is impossible that the film of the natural apatite was coated on the substrate by the current coating method of plasma spraying. The film was evaluated by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and Fourier transform infrared spectroscopy (FT-IR). Biocompatibility of the coated ATR was also examined through an animal experiment.The chemical contents and crystallinity of the coated film were similar to those of the apatite-target for PLD as a raw material. In the in vivo test by mandible of canine for observation of new bone formation within the peri-implant interface zone, experimental groups with natural and synthetic apatite films showed higher bone formation than that of the control group without the films after 8 weeks of healing. In the same in vivo test, new bone has already constructed a cancellous bone structure in the natural apatite group : clear bone growth occurred, however, no construction of the cancellous structure was found in the synthetic apatite group. It was concluded that the natural apatite ultra-thin film coating on implants with this PLD could provide higher bone integration, or better biocompatibility to a metallic and ceramic implants.