“…It would be difficult to explain the dif ferential reactivity of MFP in the presence of group IIA metal ions based on the limited data presented here. The interaction of MFP with HAp probably in volves (1) adsorption onto HAp, (2) diffusion into HAp [Jongebloed et a!., 1975;Mellberg, 1980;Borggreven et al, 1981;de Rooij et al, 1981;Ogaard et al, 1985], and (3) reaction [Ericsson, 1963] at the HAp surface. In addition, MFP uptake onto HAp in the presence of the group IIA metal ions may involve other interactions between MFP, metal ion, and HAp.…”