BIOCOMPATIBILITY SCREENING OF SILANE-TREATED HYDROXYAPATITE POWDERS, FOR USE AS FILLER IN RESORBABLE COMPOSITES

This study reports in vitro biocompatibility screening of different ki nds of silane-treated hydroxyapatite (HA) powders, for use as modified filler in resorbable composite. The silane coupling agents investigat ed were all methoxysilanes, with either vinyl (VS), or methacryloxy (M PS), or primary amine (AMMO), or secondary amine (TRIAMO), or diamine (DAS) functionality. Evaluation of cell adhesion on the different sila nized HA surfaces, indirect agar-overlay test and direct contact test on extracts showed the acute toxicity of all five free silane agents, the innocuity of strongly adsorbed silane molecules on HA surfaces and the dose-dependent toxicity of leachable silanol molecules.