A Potential Bioactive Method for Dental Tissue Engineering

The aims of this study were to isolate and identify dental pulp stem cells (DPSC); determine the effects of environmental conditions on odontogenic differentiation and define the differentiation parameters in vivo and in vitro based on dental tissue engineering concept.

Method:

The cells obtained from dental pulp tissue after human impacted third molar tooth extraction were analysed for hematopoietic and mesenchymal clusters of differentiation with flow cytometry. The odontogenic differentiation was stimulated by medium modification and bone morphogenetic protein 2 (BMP2) was used as growth factor. The histologic features were examined and expressions of enamel-dentin matrix components [Dentin sialophosphoprotein (Dspp), dentin matrix proteine 1 (Dmp1), enamelysin/matrix metalloproteinase 20 (MMP20) and phosphate-regulating gene with homologies to endopeptidases on X chromosome (Phex)] of the cells were analysed with RT-PCR at 7, 14 and 21 culture days. In the second section, DPSC were transplantated on the back of immunocompromised mice via hydroxyapatite tricalcium phosphate (HA-TCP) scaffold and at the end of six week period, histological examination and RT-PCR analysis were performed.

Result: The cells were determined to be mesenchymal stem cells having 98.3 % CD73 and CD90 double-positive cell rate. The increase in mineralization capacity and Dspp, Dmp1 enamelysin/MMP20 and Phex expressions proportional with culture period were determined after odontogenic differantiation. After transplantation period, it was determined that osteo-dentin matrix was formed in the group in which odontogenic differantiation was stimulated and the odontogenic characteristic of the matrix was confirmed by histological examination and increased expressions of matrix components determined with RT-PCR analysis. 

Conclusion:

Our findings depicted that the aforementioned odontogenic differentiation technique and scaffold complex could be used a potential bioactive method in regenerative dentistry. However, the provision of a complete dental tissue regeneration and the potential clinical usage would be possible by further developments in the technique performed.