The effect of aluminum on the rate of dissolution of calcium hydroxyapatite--a contribution to the understanding of aluminum-induced bone diseases.

Aluminum ions, Al3+, as these ions exist in aqueous solutions at pH approximately equal to 7, adsorb onto calcium hydroxyapatite (HAP) crystals and severely inhibit the dissolution process of these crystals at 0.1 microM concentrations of aluminum. Human bone crystals have also been shown to adsorb these ions or molecules. A mechanism explaining why aluminum, in connection with bone resorption, causes less demineralization in the osteoid/calcified bone region than deeper in the calcified bone, is suggested.