Effects of ascorbate-deficiency on collagen secretion and resorption in cultured mouse incisor germs.

The effects of ascorbic acid deficiency on mouse incisors, grown in vitro, has been investigated at the histological and cytological levels. In this model, continuously growing mouse incisors are characterized by the existence of different type of predentin-dentin matrix on its lingual (root-analogue) and labial (crown-analogue) surface and the absence of enamel on the lingual surface. Our observations indicated that ascorbate-deficiency affected the behavior of mouse tooth germs in vitro: odontoblast differentiation was disturbed and morphological evidence for odontoblast-mediated collagen resorption were observed. An abnormal amorphous predentin-dentin matrix existed and the basement membrane was prematurely disrupted. The dentin mineralization, as well as functional differentiation of ameloblasts were strongly hampered. Chronic deficiency led to disorganization of the dental tissues.