Dental Pulp Stem Cell Treatments and Advantages

The risk of rejection of transplant material, which can occur in bone marrow transplants and other donor stem cell procedures, is almost non-existent when dental pulp stem cells are used by the patient themselves. Potent immuno-suppressant drugs are less likely to be needed and stem cell transplants and tissue grafts are likely to have a more positive outcome. Another advantage to dental pulp stem cells is that they have a very fast replication rate in comparison to other sources of stem cells in the body. This makes them an excellent resource for rapid culture and treatment of acute conditions and, by having the teeth already stored, the normal wait between stem cell harvesting and treatment is much shorter as the stem cells can be cultured in the laboratory and then transplanted in a single procedure.

Dental pulp stem cells from children’s milk teeth are potentially even more advantageous than harvesting stem cells from adult teeth as the milk teeth have higher levels of activity and regenerative ability. Milk teeth stem cells are multipotent like bone marrow stem cells and umbilical cord blood stem cells. Multipotent stem cells can create a number of different specific tissue types such as cartilage, bone, skeletal muscle cells, heart tissue, and neural cells, meaning that they have a potentially huge number of applications in the treatment of disease (Miura, et. al., 2003). Gronthos (et al, 2006) found that dental pulp stem cells could differentiate into adipocytes and neural-like cells which may make them increasingly attractive to researchers looking for easily accessible stem cells with applications outside of haematopoietic conditions.

Treatments Using Dental Pulp Stem Cells

A number of clinical trials have been completed or are currently underway in the US and in Europe to investigate stem cell treatments for stroke, heart disease, and spinal cord injury, amongst other conditions although there are relatively few investigating dental pulp as a source of stem cells for such treatments. Other treatments, such as bone marrow transplants have been conducted successfully for many years, and there are many researchers working with umbilical cord blood stem cells and embryonic stem cells. The potential for using dental pulp stem cells is limited, currently, with most research still at the laboratory stage or only occurring in animal models. The focus is largely on the ability of dental pulp stem cells to repair and regenerate dental pulp itself and replace dentin in order to remove the necessity for root canals with Huang (et al 2010) finding that dental pulp stem cells did successfully achieve this in animal models.

Stem Cell Treatments in Humans

One clinical trial (NCT00595595) is, however, looking at the potential for dental stem cells to reduce the need for conventional root canal procedures in humans. This study in Texas is using small pieces of oral mucosa that are normally removed during a tooth extraction to isolate and culture dental pulp stem cells. These stem cells will then be applied to various scaffolds and test compounds in order to assess their ability to differentiate into different types of cell types in the normal root of a human tooth (such as odontoblasts, fibroblasts, and endothelium).

Stem Cell Niches

Further research by Huang (et al, 2009) on the presence of stem cells in dental pulp, and nearby tissue has revealed that dental pulp stem cells are not the only active stem cells in the region. Stem cells from exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSCs), stem cells from apical papilla (SCAP), and dental follicle progenitor cells (DFPCs) are also present in adult teeth. These stem cell ‘niches’ add to those already discovered in the eye, gastrointestinal tract, and elsewhere in the body.

References

Scholer, H., 2007. “The Potential of Stem Cells: An Inventory,” Human Biotechnology as Social Challenge. Ashgate Publishing, p.28.

Huang GT, Yamaza T, Shea LD, Djouad F, Kuhn NZ, Tuan RS, Shi S., Stem/progenitor cell-mediated de novo regeneration of dental pulp with newly deposited continuous layer of dentin in an in vivo model.Tissue Eng Part A. 2010 Feb;16(2):605-15.