Hydroxyapatite coating
Hydroxyapatite coating has been recommended for clinical use. These implants are superior with respect to the degree and rate of fixation in the bone as there is accelerated bone formation and maturation and lower corrosion rate around hydroxyapatite-coated implants. Bone adjacent to the implant is more organized than with other implant materials and with a high degree of mineralization. There is a greater surface area of bone apposition to implant which enhances the biomechanics and initial load-bearing capacity of the system. This enables the hydroxyapatite-coated Ti or Ti alloy implants to obtain improved bone-to-implant attachment. There is an increase in bone penetrations, enhancing fixation in areas of limited initial bone contact. Unfortunately, when implanted these often exhibit cracks or even complete loss of hydroxyapatite coating, and also show heavier colonization of micro- organisms. Therefore, are not necessarily advantageous for the long-term prognosis. Many implants have sandblasted surfaces that are subsequently acid etched. The goal of this combination technique is to render the implant surface rough (sandblasting) and optimally clean (etching).