Stem cells and dentistry: answers to seven questions

By Bruce G. Freund, DDSAs dental physicians, it is our duty to keep up with the most current technology available in order to afford our patients the best care possible. Recently, dental retrieval and storage of stem cells has become a topic of interest in the dental community. To help you understand this exciting advancement in the dental field, this article will answer some of the most commonly asked questions about stem cells.The history of stem cellsFirst, a little history ...2000: Dental pulp stem cells discovered by a researcher at the National Institutes of Health.2003: National Institutes of Health announces viable stem cells are in dental pulp of teeth.2004 to present: Over 1,000 published studies identifying therapeutic potential of dental mesenchymal stem cells.2008: Surgeons from Spain announced the world’s first tissue-engineered whole organ transplant procedure, using a trachea made with the patient’s own adult mesenchymal stem cells. (Mesenchymal stem cells are found within the dental pulp of deciduous teeth, developing third molars, and the follicular tissue surrounding unerupted or developing teeth and permanent teeth with healthy pulp.) 2009: Scientists from Italy announced the first-ever human clinical application using patients’ own dental stem cells to repair mandibular bone defects.Common questions about stem cellsWhat are stem cells?Stem cells are immature, unspecialized cells in the body that are able to grow into specialized cell types by a process known as “differentiation.” There are two primary sources of stem cells: embryonic stem cells and adult stem cells. Adult stem calls are found in many organs and tissues in the human body, including the dental pulp contained within teeth. Embryonic stem cells have the ability to grow into any cell type in the body. However, there is great ethical controversy regarding obtaining and using these stem cells for medical research and treatment purposes. Until recently, it was thought that adult stem cells could only turn into cells that were the same as those in the tissues and organs in which they were found. It is now known that adult stem cells taken from one area of the body can be transplanted into another area and grown into a completely different type of tissue. This ability to grow and regenerate tissues is the focus of the emerging field of personalized medicine, which uses a patient’s own stem cells for biologically compatible therapies and individually tailored treatments.How are stem cells being used in medicine?Stem cell-based therapies are being investigated for the treatment of many conditions, including neurodegenerative conditions such as Parkinson’s disease and multiple sclerosis, liver disease, diabetes, cardiovascular disease, autoimmune diseases, musculoskeletal disorders, and nerve regeneration following brain or spinal cord injury. Currently, patients are being treated using stem cells for bone fractures, cancer (bone marrow transplants), and spinal fusion surgery. New stem cell therapies are continually under review, or have already been approved by the U.S. Food and Drug Administration. Many other therapies are in various stages of product development. As the number of people affected by degenerative diseases continues to increase, there will be a greater need for new treatment options for the ever-growing aging population. Harvesting and storing stem cells now will ensure their availability in the future when they will be needed most.How difficult is it to obtain stem cells to bank for future use?In the case of dental stem cells, the process is not at all difficult. In fact, it is easy. Healthy stem cells are discarded on a daily basis as the result of routine dental procedures (tooth extractions). The stem cells contained within the pulp of healthy teeth are the most easily accessible stem cells that can be recovered. When compared to other types of stem cells and their corresponding methods of recovery — i.e., stem cells obtained from embryos, cord blood, bone marrow, adipose (fat tissue), and peripheral blood — obtaining stem cells from teeth is ethically uncontroversial, non-invasive, less dependent on timing, and far less expensive. As opposed to stem cell recovery from cord blood, wherein there is one single opportunity immediately following the birth of a child, there are numerous opportunities to obtain stem cells from teeth. It is best, however, to recover and store dental stem cells at an early age. Those obtained from the extracted loose baby teeth of a healthy child and those extracted from a healthy adolescent (i.e., bicuspid teeth removed in preparation for orthodontic treatment and extracted wisdom teeth) are ideal.Why should I consider banking stem cells from my or my child's teeth?Tooth-derived stem cells are readily accessible and provide an easy and minimally invasive way to obtain and store stem cells for future use. Banking one's own tooth-derived stem cells is a reasonable and simple alternative to harvesting stem cells from other tissues. Obtaining stem cells from baby teeth is simple and convenient, with little or no trauma. Every child loses baby teeth, which creates the perfect opportunity to recover and store this convenient source of stem cells — should they be needed to treat future injuries or ailments — and presents a far better alternative to simply discarding the teeth or storing them as mementos. Furthermore, using one's own stem cells poses few, if any, risks for developing immune reactions or rejection following transplantation, and also eliminates the potential of contracting disease from donor cells. Stem cells can also be recovered from developing wisdom teeth and permanent teeth. Individuals have different opportunities at different stages of life to bank these valuable stem cells. It is best to recover stem cells when you or your child is young and healthy and the cells are strong and proliferative.When can I bank stem cells from my child's teeth or from my own teeth?With regard to your children, the best time to recover baby teeth with stem cells is before the teeth become very loose, as the cells in the dental pulp will remain more viable if they continue to have a blood supply. Your dentist will determine the optimal time for the removal of these teeth. StemSave provides you with the opportunity to recover the teeth for stem cell preservation once the teeth have been removed. Remember that your child will not be sacrificing a tooth, as baby teeth are lost naturally to allow for the permanent teeth to erupt. Adolescents have two excellent opportunities for banking their dental stem cells: following extraction of bicuspid teeth in preparation for orthodontic treatment, and after the extraction of their wisdom teeth. Although these teeth are typically discarded, you can ask your dentist to participate in the StemSave program, which provides an opportunity to recover and preserve your family’s dental stem cells.Are stem cells being used today to treat any systemic diseases?Yes. Mesenchymal stem cells are being used to treat cardiac infarctions, muscular dystrophy, Parkinson’s disease, liver disease, etc.If I do not have neurological damage or some other stem cell therapy-associated disease, why should I care about stem cells?On the surface, stem cells might seem irrelevant to you because you lack certain disorders, such as spinal cord injury, diabetes, etc. However, stem cells could be important to any disease due to their unique property of being forever "young" and being responsive to change. An understanding of these properties would lead to insights into the biology of other diseases. For example, an individual might have a condition that could eventually lead to a disorder such as Parkinson’s. By understanding the biology of stem cells, drugs could be developed to prevent the dysfunction of stem cells.