Zinc incorporation in human dental calculus

We present here the first study of the local environment of zinc ions in bi ological calcium phosphates. It was suggested from in vitro studies that zi nc inhibits the formation of hydroxyapatite and promotes the formation of m ore soluble phases, like tricalcium phosphate. Several mechanisms of zinc - calcium phosphate interaction were proposed, yielding either to the adsorp tion or to the incorporation of zinc ions into the phosphate structure. The results obtained here show that, under in vivo conditions, the zinc atoms are fully incorporated into the crystalline structure of the calcium phosph ates.