A process for the preparation of a hydroxyapatite, which is suitable as a tooth-cleaning substance, by precipitation from aqueous phosphoric acid and calcium hydroxide solution, in which a calcium-doped phosphoric acid solution is fed to an intensive mixer with a suspension of calcium hydroxide/oxide...http://www.google.com.au/patents/US5405436?utm_source=gb-gplus-sharePatent US5405436 - Process for the preparation of hydroxyapatite
