Synthesis by Precipitation Methods of Apatite Containing Rare-Earth Elements for Artificial Dental Roots

Abstract

It is now recognized that sintered apatite, which has been used as an artificial dental root material, fails to induce osteogenesis in vivo. This may in part be due to its low solubility in body fluids. We developed alternative methods to produce a novel apatite that induces physiological responses as an artificial dental root material. This was done by introducing rare-earth elements into apatite by precipitation methods.
      We found considerable amounts of apatite could be obtained by the precipitation method, whereby apatite was synthesized from a mixture of calcium nitrate and phosphoric acid when sodium hydroxide was gradually added to the mixture. Rare-earth phosphate was produced in crystal form when rare-earth nitrate was present in the mixture. Further, although the precipitation method produced apatite containing rare-earth elements when a complex of rare-earth and ethylenediamine-tetraacetic acid (EDTA) was present, this combination suppressed generation of rare-earth phosphate.