Metals and polymers have received considerable attention with respect to their potential use in human implantation. Serious study of the ceramics for this purpose has only recently begun. Materials for implantation in any body site must meet certain requirements. Each class of material has been found to have some highly desirable properties as well as some undesirable characteristics. Materials for use in dental implantation, particularly for the replacement of individual teeth, are subjected to environmental factors not generally existent in other implantation sites. Preliminary studies of the ceramics have suggested that, from the physiologic standpoint, they may be the best implantable substitute for hard tissues (bones and teeth) yet achieved. There are, however, many questions remaining to be answered concerning the selection of the most suitable material, its fabrication, and the reaction of tissues to it. These questions should serve to indicate future areas of exploration.