Biocompatibility and bioactivity of hydroxyapatite whiskers reinforced bis-GMA based composites

Novel bioactive bis-GMA-based resin composites were successfully developed by incorporating hydroxyapatite (HA) whiskers in the polymeric matrix. The whiskers had good dispersibility and wettability with bis-GMA-based polymer, showing good bonding with the matrix, which conferred good reinforcement. The mechanical properties of the composites were significantly enhanced when compared with the particulate filler. The morphology change of HA did not cause obvious variations in the proliferation and viability of L929 cells and the apatite-forming ability of the composites in SBF. The in vitro cytotoxicity of the composites was depressed by addition of hydroxyapatite filing materials. Such a favorable response indicated an important similarity in surface chemistry of the HA filler, and HA whiskers appeared to have potential as most promising reinforcements for resin-based polymers.