[Growth of the tooth root after radiation--an animal experimental study].

The extent to which root growth and tooth eruption can be influenced by irradiation trauma was studied in beagle dogs. A cobalt 60 teletherapy apparatus with various dosages between 600 rad and 2400 rad was used to inflict the trauma on the maxilla and mandible. The results showed that the delay in tooth eruption was dependent on the dosage, but erruption could not be hindered. Longitudinal growth of the roots of irradiation, independent of the level of the dose. The periodontal fibers were normally aligned as with healthy teeth; the apex was formed predominantly by surplus cellular cement.