[Cellular competition and healing]

Different therapeutic solutions have been tried to obtain a new attachment. Several animal experiments have studied cellular colonization of radicular surfaces exposed to the disease then planed. Only the cells from the periodontal ligament seem to be able to form a new attachment. The interposition of a membrane seem to prevent gingival and osseous tissues to interfere with the periodontal ligament. The periodontal ligament cells colonize then the radicular surface.