Preventive goals in oral implantology.

Preventive dentistry is mainly concerned with caries and periodontal disease and little or no attention is paid to the prevention of alveolar bone loss. An overdenture contributes to the preservation of alveolar bone and offers a number of advantages in comparison to a conventional complete denture. After tooth extraction the atrophy of edentulous lower jaws can be prevented or delayed by using implants supporting an overdenture or a fixed mandibular prosthesis. Hydroxyapatite implants have been studied as submerged tooth root substitutes and have proven to be able to preserve the bulk of the alveolar ridge. A drawback of this submucosal implant is that the ridge maintenance depends solely on the physical presence of the hydroxyapatite implants. If implants support an overdenture or a fixed prosthesis they also play a role in maintaining the function of the bone in the different stages of reduction of the mandible. In this paper a classification for the different resorption stages of the mandible is presented and is used to determine the correct moment for preventive implantology. In addition the use of a lingualised occlusion is discussed as a contribution to the preventive goals in oral implantology.