The effects of polyvalent salts on zeta potential of bone.

A streaming potential experiment was conducted on in vitro bone to determine the effects polyvalent salts have on bone zeta potential. Polyvalent metal salts would be introduced into local physiological electrolytes by corrosion of a metal implant or dissolution of a ceramic implant. It was hypothesized that a change in zeta potential of mineralized tissue, resulting from the introduction of polyvalent salts, could be a cause of tissue instability at the implant interface. Zeta potentials measured in bone were on the order of a few millivolts. Strongly hydrolytic metal cations such as Al+3 and Fe+3 did not have sufficient activity in buffered neutral electrolytes to alter bone zeta potential. Results suggest that less hydrolytic cations of high valence, and large polarizable anions may affect bone zeta potential.