Isolation of dental papilla from young rat lower incisor by three step digestion.

In order to establish an in vitro model system, a three step digestion procedure, trypsin + collagenase pretreatment, followed by trypsin or collagenase treatment, and then trypsin posttreatment, was employed for the dissociation of rat lower incisors into dental papilla and enamel organ. Both the pre- and post-treatments promoted destruction of the basement membrane located between the dental papilla and enamel organ, resulting in effective dissociation of the tissues. The isolated dental papilla, including differentiating odontoblasts, was well preserved after this treatment. The results indicated that the three step digestive treatment may be very useful in isolating the dental papilla from the rat-incisor enamel organ accompanied by the basement membrane. The material provides a model system for studying odontoblast differentiation, development, and maturation in vitro.