The objective of this study was to produce a ceramic that can be used as a hard tissue implant. After investigation of several mixtures of tricalcium phosphate, calcium fluoride, magnesium carbonate and alumina, a composite of fluorapatite and spinel was selected as the ceramic material. The ability to prepare sound samples and the minimum solubility in tissue fluids were the main reasons for the selection of a composite with one mole of fluorapatite to three moles of magnesium aluminate spinel;The ceramic was tested to determine the effect of porosity on strength so that the optimum combination of microstructure and mechanical properties could be obtained. The effect of the duration of stay in the physiological environment on the bending strength was determined after in vitro tests in Ringer's solution for porous and non-porous bars, and also after in vivo tests of non-porous subcutaneous implants;Porous bone bridges implanted in dogs were studied in terms of bone ingrowth, implant stabilization and tissue compatibility. Thin sections of the bone-ceramic interface were prepared and analyzed using optical microscopy with polarized transmitted light;The results of the tests in vivo and in vitro showed that the fluorapatite-spinel ceramic can be successfully used as a permanent hard tissue implant.