HYDROSUB cs is a 100% synthetic biomaterial ceramic powder composed by 65% Hydroxyapatite (HAP = Ca10(PO4)6(OH)2) and 35% of Tricalcium Phosphate (TCP = Ca3(PO4)2). Ca10(PO4)6(OH)2 is closest to the biological apatite crystals. The atomic ratio Ca/P (1,67) is lower than that of the bone. The resorption of beta tricalcium phosphate is largely higher than hydroxylapatite. The hydroxyapatite and beta tricalcium phosphate are recognized since many years for theirs properties of biocompatibility, osteoconduction, and also resorption.