The Effects of Reducing Function and Stopping Eruption on the Periodontium of the Rat Incisor

Abstract

The lower incisor teeth of rats were subjected to the following changes: eruption was stopped and normal function maintained by fitting a metal crown over both incisors; and eruption was stopped and function reduced in 1 incisor by root filling it or by pinning it to the bone, the tooth being kept out of occlusion. The normal peridontal membrane was described. The alveolar fibers depended on function for their maintenance, while the cemental fibers did not. The fibers of the intermediate plexus, adopted a longitudinal orientation when not required to connect alveolar and cemental fibers. The intermediate plexus fibers became grouped into bundles which were continuous with the alveolar and cemental bundles after eruption stopped. Complete root filling prevented tooth eruption. This suggests that the periodontal membrane plays no part in eruption but that the pulp does.