Porous ceramic (Al2O3) material was used in combination with titanium fixtures as subperiosteal transmucosal implants in three patients at the Department of Oral Surgery and Oral Medicine, Dental Faculty, University of Oslo. Ceramic pieces were furnished with titanium receptacles and matching threaded posts. The implantation approach was based upon two stages, the first for subperiosteal placement of the ceramic onlay segment containing the titanium receptacles, and the second procedure for perforation of the mucosa and insertion of the posts intended for prosthetic use. A healing period of 8 weeks was planned between the two procedures. In one of the patients, however, the implants were removed only a few weeks after placement because of inflammation and soft tissue breakdown over the ceramic material. Reoperation was performed, however, with the same negative results. The other two individuals retained the implants, with uneventful postoperative healing periods. Between 6 and 8 weeks after mucosal perforation and insertion of the titanium posts, however, subjective and objective symptoms of infection were registered in both patients. In addition, one of the cases exhibited dehiscence and exposure of the ceramic. The implants were removed in both individuals.