**3.5 Hydroxyapatites implants**

Hydroxyapatite is a bioceramic of great clinical interest due to its nontoxicity, bioactivity, good biocompatibility, osteoconductivity, and its non-inflammatory nature. However, since it has a high elasticity modulus (brittle), hydroxyapatite is usually associated to other materials to form an implant in load-bearing applications. In fact, implants for load bearing, such as titanium screw, can be coated with


### **Table 4.**

*Properties of hydroxyapatites coat [117].*

### *Recent Advances in Ceramic Materials for Dentistry DOI: http://dx.doi.org/10.5772/intechopen.96890*

hydroxyapatite. The application of hydroxyapatite coatings is an interesting surface amendment on dental implants [116]. As its coatings apply on implanted material, it provides enough calcium and phosphate ions at initial implantation stage and makes the implant material biocompatible [117]. The properties of hydroxyapatites are given in **Table 4**.

However, hydroxyapatite has osteogenic nature and is able to form strong bond with host tissues, so it is widely used in biomedical field for osteointegration, bone replacement and regeneration, coating metallic implants, and to fill the defects generated in bones [118].
