Colchicine's effects on rat incisor odontoblasts and dentinogenesis.

Colchicine (CLC) in doses of 0.5 and 1.5 mg/kg was administered to 40 female Wistar rats in two equal groups. The animals were sacrificed after 5 h, 24 h, 3 d and 7 d, and the effects of CLC on pulp, odontoblasts and dentin in the continuously growing incisors were studied. With the lowest dose a few arrested mitoses were observed in the germinative part of the pulp after 5 and 24 h. With the highest dose an increasing number of mitoses were observed in the germinative part of the pulp after 5 and 24 h. More incisally the odontoblasts were pale, swollen and granulated after 5 h, and necrotic and disintegrated after 24 h. After 3 and 7 d dentinal derangements, consisting of moderately and severely irregular dentin, osteodentin and a niche-like defect in the labial dentin, were seen. Labially one or two incremental lines traversed the dentin from the apical to the incisal part of the incisors.