Empirical Border Lines of the Apatite Stability Field in the System CaO—P₂O₅—H₂O —Na₂O—CO₂—MX at Room Temperature

Literature data on equilibria between solid calcium phosphates having the apatite structure and aqueous solutions containing Na + and CO 3 2- ions were reexamined in view of the present data about the complexation of ions in such systems. Recalculations showed that all solutions were undersaturated or just saturated with respect to either brushite or octocalciumphosphate or more or less finely dispersed calcite and supersaturated with respect to pure hydroxylapatite. Sections through the quasi-sextary phase diagram were constructed which are representative for the system under simulated in vivo conditions.