Dental stem cells are found in the dental pulp (soft tissue inside the tooth). 
Milk teeth and wisdom teeth are a good source of stem cells. They are mesenchymal in nature and are multipotent i.e have the potential to regenerate different tissues like bone, muscle, nerve, fat, tooth, cartilage and pancreas.
Milk teeth fall naturally between the age of 5 and 12. Rather than discarding them, they could be used to obtain life saving stem cells.