Calcium phosphate ceramics, especially hydroxyapatite (HA) are currently used as biomaterials for many applications in both dentistry and orthopaedics, because they form a real bond with the surrounding bone tissue when implanted. Nevertheless, due to the poor mechanical properties of bulk HA ceramics, these cannot be used as implant devices to replace large bony defects or for load-bearing applications. In those cases, titanium-based devices find their field of utilization. For this reason, much e⁄ort has been devoted in the last decade, towards the application of HA as a coating on metallic substrates, in order to improve fixation and promote osteointegration of cementless titanium-based implant devices.
The plasma-spray (PS) technique is currently the only method commercially available for coatingimplant devices with HA. But the PS HA coatings, although exhibiting a very good biocompatibility,present some disadvantages a⁄ecting the longterm stability of the implant and, therefore, its lifetime. Among these drawbacks, the most significant are the poor coating—substrate adherence(making it necessary to introduce a grit-blasting surface treatment prior to the coating procedure, in order to guarantee a minimum adhesion of the coating) and the lack of uniformity of the coating from two di⁄erent points of view: morphology and crystallinity.
本文由桑尧热喷涂网收集整理。本站文章未经允许不得转载；如欲转载请注明出处，北京桑尧科技开发有限公司网址：http://www.sunspraying.com/
|
