Effect of vincristine on odontoblasts in rat incisor.

Vincristine in doses of 0.1, 0.3, 0.5 and 0.7 mg/kg was administered to 60 rats in four groups. Histomorphologic investigation of the odontoblast population in the maxillary incisors revealed dose-dependent reactions consisting of (1) swelling of the odontoblasts and an accumulation of abnormal mitotic cells in the germinative parts of the pulp after 5 h, (2) a supervening necrosis and destruction of some odontoblasts and of the mitotic cells after 24 h, and (3) after 3 d, a reversal to normal structure in some parts of the odontoblast population, but a further development of the vincristine-induced changes, with severe cellular derangement and irregular predentin production, in others.