Optical microscopy, scanning electron microscopy and X-ray microanalysis (EDS system) were used on c.p. titanium devices (21 grids and 10 plates) removed from 28 patients without signs of inflammation 6-24 months after surgery. Plates, grids and surrounding tissue were investigated to evaluate the titanium release and accumulation. Titanium was only present in the interfacial bone, probably due to fretting, and in all fibrous tissue surrounding the devices. Titanium content followed a decreasing gradient extending from the device surface and was not detected at a distance greater than 1mm. High titanium levels were found in blood cells in the connective tissue. In conclusion, titanium release from the devices stops only after bone is laid down on the titanium surfaces. Titanium release does not seem to interfere with the osteogenic process but perhaps may interact with it.