Radiographic Approach according Tooth Development based on Stem Cell Harvesting

Medicine Regenerative research is a promising alternative field for clinical treatments and complementary exams may be necessary. We demonstrated the successful use of tissue engineering approaches to generate bioengineered tooth crowns from harvested pig and rat post-natal dental stem cells (DSCs) (Young et al, 2002, Duailibi et al.,2004,2008,2011).  To facilitate characterizations of hDSC, we have developed a novel radiographic staging system to accurately correlate human third molar tooth developmental stage with harvested hDSC yield. Objective: our studies are to describe radiographic approaches of these stages, facilitating a diagnosis method for identifying by a professional, a best stage of quantity and quality of cells populations creating guided protocols for future clinical applications. Method: 73 human teeth (CEP- CAAE 0166.0.017.000-11) were analyzed by dental pariapical xRay system (intrex, Keystone inc. Hatfield, PA)  and Cone Beam Computer Tomography (CBCT) preXion 3D (Co.LTD Tokyo, Japan). Data analyses were performed by Invesallius software (CTI, 3D Technology Dept. Campinas, Brazil) to compute pulp chamber volume. Tooth/pulp area ratio, tooth/pulp length ratio, tooth/root length ratio and tooth/pulp volume ratio were measured by Osirix software (Pixmeo, Co.,Geneva, Switzerland). Result: we demonstrated that hDSC yields were higher in less developed teeth (Stages 1 and 2), and lower in more developed teeth (Stage 3, 4, and 5).  The greatest cell yields and colonies forming units (CFU) capability was obtained from stage 1 and 2 tooth dental pulp. Radiographically, we cannot identify tooth stages by tooth/pulp area ratio and tooth/pulp volume ratio methods. We could only indicate tooth stages by tooth/pulp length ratio and tooth/root length ratio. Conclusion: We conclude that radiographic developmental staging can be used to accurately assess the utility of harvested human teeth for future dental tissue engineering applications. Tooth/pulp length ratio and tooth/root length ratio should be the correct methodology for classification tooth stages.