[The effect of doxorubicin on the unimpeded eruption rates of rat mandibular incisors].

We examined the effects of daily injections of doxorubicin, an anti-tumor drug, on unimpeded eruption rates, pulp cells, odontoblasts, periodontal ligament and dentine formation in the rat mandibular incisor. The experimental animals were intraperitoneally injected with 5 mg of doxorubicin/kg body weight/day for a period of 7 days. The eruption rates decreased gradually; and on the seventh day, the mean eruption rate had decreased to 14% of the control value. In addition, we noticed marked destruction of pulp cells and periodontal cells at the basal region of the incisor. The amount of dentine formation was measured using the tetracycline labeling method, but significant decreases in dentine formation were not observed. These results suggest that destruction of the basal tissues is related to inhibition of incisor eruption rates, but that tooth eruption is not related to dentine formation.