[Healthy periodontal tissue, periodontitis and its cure].

A well known development of the chronic periodontal disease is reviewed. However, the histological picture of gingiva varies at a much lower speed than its clinical picture, and slower than previously described. In presence of periodontitis there may exist a zone of reversible disease of about 2 mm, which gives the possibility of obtaining a re-attachment of unknown magnitude. A new connective tissue attachment (on top of the re-attachment) seems only possible if the periodontal ligament cells are allowed to proliferate coronally.