Surface Modification of Bioinert Ceramics Enhances Osseointegration in an Animal Model

The aim of this experimental study was to screen different surface structures of alumina and zirconia ceramic implants for their osteointegration properties. Alumina and zirconia ceramic test implants having different surface structures (smooth, macro-structured, corundum-blasted, porous) were implanted in the femora of mini-pigs, and left in situ for 12 weeks. After removal, the implants were evaluated macroradiographically and histologically. The smooth and macro-structured ceramic surfaces showed virtually no bony ingrowth, neither in the cortical nor the cancellous bone areas. In contrast, a rough surface finish or a porous surface structure allowed extensive bony ingrowth. The osteointegration rates varied between 20.5% and 41.7% (cancellous bone), and between 26.0% and 52.8% (cortical bone). With regard to the development of ceramic implants for clinical use, for example in the field of total hip replacement, these data provide a basis for further, more comprehensive studies.