Title : Multiple ion-substituted hydroxyfluorapatites bioceramics
Bioceramics intended for replacement of failure bone and dentines have two important characteristics: the biocompatibility and their ability to absorb at a rate similar to bone growth. Calcium phosphate such as hydroxyapatite and/or fluorapatite (H-FAp, Ca10(PO4)6OH2/F2) are the eminent bioceramics widely used in various biomedical applications, mainly in orthopedics and dentistry reparation due to their close similarities with inorganic mineral component of bone and teeth. In fact due to the complexity of the chemical composition of bone and dentine which contain several elements till now no material like natural one was synthesized. All the existing researches tried to obtain the material the more equivalent. As far as we are concerned several attempts to introduce the maximum number of ions into the structure of hydry/fluor-apatite have been established. Thus mangnesium Mg2+, strontium Sr2+, zinc Zn2+, sodium Na+, potassium K+, carbonates CO32-, fluorides F- and chlorides Cl- ions were inserted in the apatite structure. The synthesized materials were characterized by several techniques (DRX, FTIR, Chemical anlysis, G-DTA, 31P NMR, Raman, SEM, ...) to verify the purity and confirming their insertion in the structure. After that the materials were pressurelessly sintered and the densification conditions were optimized. The densest materials were also mechanically characterized. The biological properties of the dense bodies were in-vitro tested; the bioactivity and the biocomtability of the materials were defined. The suitable materials were in the last step tested in-vivo for their possible application as bone and dentine substitutes.