Effects of colchicine and hydrocortisone on unimpeded eruption rates of root-resected mandibular incisors of rats.

A single injection of colchicine and daily injections of hydrocortisone have opposite effects on tooth eruption, respectively causing marked reduction and marked increase in unimpeded eruption rates in the root-resected incisors of rats. Unimpeded eruption rates of both root-resected and normal, non-resected, incisors responded identically to these two drugs, providing support for the view that the eruptive process following root resection is physiological. It was not possible to obtain direct evidence relating to either the hydrostatic pressure or the periodontal fibroblast hypotheses of tooth eruption; the drugs used to affect the eruption rates of resected rat incisors could also affect either the tissue hydrostatic pressure or the motility or contractibility of periodontal fibroblasts or both.