Effects of various culture conditions on matrix formative functions of rat incisor odontoblasts in a pulp-dentin slice culture system.

An attempt to develop a new pulp-dentin slice culture system was carried out using thin slices of rat incisors in order to obtain a better culture method which will be useful for studies of the physiological function of odontoblasts including the mechanism of dentiogenesis. The thin slices of incisors were prepared from mandibles of 4-5-day-old rats, using original equipment that was developed in the present study. They were incubated under stationary and rocking culture conditions with two oxygen tensions (50 and 95%). The hyperbaric condition (30% O2, 2 atm) was also tested. Histological observations, [3H]-proline uptake examination and [3H]-proline autoradiography were carried out in order to estimate the matrix formative ability of odontoblasts. The results showed that the pulp-dentin slice culture system successfully preserved the viability and the matrix formative function of odontoblasts. The rocking culture was more favorable than the stationary culture to maintain the cell viability. The higher oxygen tension improved the matrix formative function of odontoblasts. Satisfactory results were obtained from the rocking culture (95% O2) and the hyperbaric stationary culture (30% O2, 2 atm). These results suggest that a large amount of oxygen may be required for maintaining the functions of odontoblasts in this new pulp-dentin slice culture system.