Bone ingrowth into micropores of hydroxyapatite coated titanium plates

Abstract

An innovative thermal decomposition method has been used to coat hydroxyapatite (HA) on to porous Ti plates to judge its efficiency in promoting bone ingrowth. Canine implantation tests were carried out to determine the histologic features of the coating, which was as thin as 2μm. Micropores 50, 100, 200, and 300 11min diameter were made in both coated and uncoated Ti plates. The H A coated plates were characterised by chemical analysis, X-ray diffractometry (XRD), EDX, and SEM observations. Chemical analysis by ICP indicated that the Ca: P ratio of the hydroxyapatite coating was 1·65. The XRD patterns revealed that the coated layer consisted of HA and β- TCP (tricalcium phosphate) phases. Bone tissue reaction inside the pores was examined histologically at 2, 4, 8, and 16 weeks after implantation. The differences in ingrowth between the control and coated plates led to the conclusion that while there were similarities in such growth, the coated plates proved to have greater levels of better quality ingrowth. Initially, the larger 300 μmsized holes exhibited better ingrowth, but there were no evident differences in ingrowth between the pore sizes in the final analysis regardless of whether they were coated or uncoated.