Three types of implant materials, a) fibre-reinforced composite (FRC) consisted of a dense core and a porous surface layer including S53P4 bioactive glass granules, b) polymer with a solid surface and c) titanium, were tested in a preclinical study in rabbits. Rod-shaped implants were placed in distal part of a femur and a proximal part of a tibia. The follow-up times were 3, 6 and 12 weeks. Histological evaluation at 12 weeks revealed new bone growth into the porous surface structure of fibre-reinforced implants.
Connective fibrous tissue capsules were clearly thicker around solid polymer implants than around titanium implants. The results of a push-out test showed statistically significantly higher shear forces at the FRC – bone interface than those at polymer –bone or titanium – bone interface. Finite element analysis revealed that the porous FRC implant distributed the shear stress over the bone – implant interface more evenly than porous polymer or titanium implants.