Tissue compatibility of different intracranial implant materials: in-vivo and in-vitro studies

Tissue compatibility of different intracranial implant materials was studied by a tissue culture method using fibroblasts. The same materials were implanted in the crania of rabbits for two months. Undecalcified sections of rabbit crania, including the materials, were stained with Fuchsin and Methylene Blue and Masson-Goldner methods. Soft X-ray was used to detect new bone formation. The materials used were alumina ceramics, hydroxy apatite ceramics, titanium, methylmethacrylate, Sugita aneurysm clip, silicon shunt tube and lyophilized human dura mater (Lyo-dura). Both alumina ceramics and hydroxy apatite ceramics showed an excellent tissue compatibility in-vivo experiments. Although alumina ceramics showed an excellent tissue compatability in in-vitro experiments, hydroxy apatite ceramics showed less compatibility. Methylmethacrylate prepared one week before the experiment showed excellent compatibility, but the same material prepared at the time of experiment showed only fair compatibility. The titanium and silicon shunt tube showed excellent compatibility. The Sugita aneurysm clip, made from elgiloy, showed fair compatibility, while Lyo-dura showed excellent compatibility in in-vitro experiments, but less compatibility in in-vivo experiments. The reasons for the differences between the results of in-vivo and in-vitro experiments are discussed.