Estudo da influência dos íons K+, Mg2+, SO4(2-) e CO3(2-) na cristaliza??o biomimética de fosfato de cálcio amorfo (ACP) e convers?o a fosfato octacálcico (OCP)

摘要

The crystallization of hydroxyapatite (HA) in aqueous solution can be described by the mechanism ACP -> OCP -> HA. In this work, it was studied the influence of K+, Mg2+, SO4(2-) and CO3(2-) ions in the formation of ACP and in its conversion to OCP, using biomimetic coatings on metallic substrates of commercially pure titanium (Ti c.p.). The results showed that Mg2+ and CO3(2-) ions favored both the formation of ACP and its conversion to OCP. Differently, K+ and SO4(2-) ions did not influence the formation of ACP and, consequently, interfered in the conversion to OCP.