Culturing human dental pulp explants in vitro

Regeneration of pulp tissue in vitro has great potential for the management of non-vital teeth. Optimisation of the culture medium will aid regeneration, this can be assessed by monitoring markers of odontoblast differentiation such as DentinSialophosphoprotein (DSPP) or markers of predentine matrix remodeling such as Matrix Metalloproteinase (MMP).

Objectives: Determine the influence of the culture medium on DSPP and MMP-2 and -9 expression

Methods: Permanent teeth that were extracted for orthodontic purposes were obtained. These were immediately transported to the laboratory in transport media in order to maintain cell viability. Within 2 hours, the pulp was extirpated and scissor minced under sterile conditions. This was then cultured in the basic medium (DMEM, 10% fetal calf serum, 1% penicillin and 1% amphotericin B) at 37¨¬C, 5% CO2 in a humidified incubator. Samples were cultured either in the mineralising medium (basic medium + 1% b-glycerophosphate + 1% dexamethasone + 1% ascorbic acid) or the basic medium. mRNA expression of the odontoblast differentiation marker (DSPP) was assessed by real time PCR and MMP-2 and -9 activity was assessed by gelatine zymography.

Results: Pulp explants from three teeth were used. At day 15 of culture, cells cultured in mineralizing medium had greater expression of DSPP than cells cultured in basic medium and either showed similar or greater expression of MMP.

Conclusions: Culturing pulp explants in the mineralizing medium resulted in greater expression of DSPP and MMPs.