Histological and biochemical studies of vitamin C requirements of hamster molars during development in vitro.

The dose response relationship between medium concentrations of vitamin C (0-350 micrograms/ml) and the hydroxylation of in vitro incorporated 3H-proline showed that in (small) 2nd molars 50 micrograms/ml vit C at level of a maximum hydroxylation was attained at whereas in (larger) 1st molars higher medium concentrations seemed to be required (150 micrograms/ml or more). No cytotoxic effects were observed in media containing concentrations of vit C up to 350 micrograms/ml. In the absence of vit C odontoblasts in young 2nd molars failed to differentiate normally and an abnormal jelly-like substance was produced. Dentinogenesis in the 2nd molars was normal in the presence of at least 50 micrograms/ml vit C. In the 1st molars, in which production of collagenous dentine matrix had already started at the time of explantation, significantly less 3H-hydroxyproline was measured during vit C deficiency as early as the first day of culture, suggesting that there is a high need for vit C during dentinogenesis in vitro.