Long-term tissue tolerance of titanium-encapsulated cobalt-samarium implants

The tissue reactions of titanium-coated cobalt-samarium magnets were investigated following their full-thickness implantation into the skulls of dogs and pigs (six of each species). The implants, together with the surrounding bone, were removed en bloc 1, 2, 3, 6, 9, and 12 months postoperatively. Following physical and radiological examinations, the excised samples were subjected to histologic investigation. The osseointegration process was observed to follow a normal course around the titanium capsule. The magnetic field did not give rise to any tissue changes that could be demonstrated by means of classical histologic methods.