Subcutaneous inflammatory reaction to a synthetic auditory ossicle (Bioceram) in rats

Cellular response and inflammatory reaction to synthetic auditory ossicle (Bioceram) made from aluminium oxide are investigated. Local inflammatory effects are important in wound healing and in determining biocompatibility of an implant, necessitating the study of biologic effects of implants, especially inflammation and fibrous capsule formation. Bioceram discs were implanted subcutaneously in the interscapular region of rats for various periods of time, ranging from 1 day to 300 days. Histological sections 6 microns thick were stained with haematoxylin and eosin. Cell types around the implants were examined quantitatively by light microscopy. Inflammatory cell reaction to Bioceram decreased rapidly within 14 days, similar to the reaction in control groups. From 30 days to 300 days after implantation, there was continuous reduction to very low levels for macrophages and lymphocytes, but fibrous connective tissue capsule around implants matured. Preliminary results suggest that Bioceram is a satisfactory biocompatible material for reconstructive surgery from the viewpoint of cellular response. We also briefly discuss the different tissue responses in light of our previous study on hydroxyapatite (Apaceram).