Dental papilla cells in culture. Comparison of morphology, growth and collagen synthesis with two other dental-related embryonic mesenchymal cell populations.

The dental papilla is a mesenchymal cell condensation which plays an important regulatory role during tooth development. Dental papilla mesenchymes were enzymatically separated from the dental epithelia from tooth germs of 17-day-old mouse embryos and disaggregated for monolayer culture. These cells were compared with gingival mesenchyme overlying the same tooth germs and with undifferentiated jaw mesenchyme from mandibles of 11-day-old embryos. The dental papilla cells were large and flat with numerous cell processes, whereas the gingival cells resembled typical spindle-shaped fibroblasts and grew to a higher cell density. Although the two mesenchymes differ in their collagen contents in vivo, no differences were detected either in the amount or type of collagen synthesized in vitro. Type I and III collagens were found in the culture media and type V collagen in the cell layer of both cell populations. The mandibular mesenchymal cells of the younger embryos resembled the dental papilla cells in morphology and growth rate. This may reflect retention of undifferentiated embryonic characteristics in the dental papilla. The successful culture of dental papilla cells now enables subsequent studies on the cellular properties related to the unique morphogenetic capabilities of these cells.