Effects of vitamin B12 in culture medium for calcified nodule formation by rat dental pulp cells.

BACKGROUND/PURPOSE: Tooth or bone regeneration requires large numbers of mesenchymal stem cells (MSCs). Although dental pulp is a suitable cell source, the number of MSCs present in this tissue is limited and they require a long period for regeneration. Therefore, the present study investigated vitamin B12 (Vb12) as an osteoinductive factor for MSCs obtained from dental pulp.

MATERIALS AND METHODS

Dental pulp tissue was removed from the root canals of the extracted mandibular incisors of three 6-week-old male Fischer 344/N Slc rats using an endodontic file and whole cells were harvested. After the primary culture, cells were sub-cultured for calcified nodule formation in MEM containing dexamethasone (Dex), β-glycerophosphate (β-GP), vitamin C (Vc), and Vb12. Calcified nodules were confirmed under an inverted phase-contrast microscope. The alkaline phosphatase (ALP) activity of cells and quantity of Ca in calcified nodules were measured. Results were analyzed using the Tukey-Kramer test.

RESULTS

Densely arranged calcified nodules were microscopically observed after the subculture of cells with Dex, β-GP, Vc, and Vb12. The ALP activity level was 0.077 ± 0.023 μmol/μg DNA in MEM supplemented with Vb12, which did not significantly differ from that without Vb12. A mass of calcium nodules formed in culture medium containing Dex, β-GP, Vc, and Vb12. The quantity of Ca increased from 13.04 ± 0.44 to 20.91 ± 0.56 mg/dL ( < 0.01).

CONCLUSION

Vb12 is effective for tooth or bone regeneration by the MSCs of rats and is useful as an osteoinductive factor for MSCs.