By: Arya Bhatt
Stem cells have been at the forefront of scientific research and have been an invaluable tool in the scientific field due to their fantastic properties. Their ability to divide over and over again to produce many new cells whilst specialising in the different types of cells the body requires has enabled researchers to explore this phenomenon and implement it into a wider variety of scenarios, most of which deal with the treatment of diseases which were thought to be incurable. Now with stem cell research expanding and its uses becoming more prevalent, one growing use of it is within restorative dentistry. Restorative dentistry involves the study, diagnosis and integrated management of diseases of the oral cavity, the teeth and supporting structures.1 One of the many treatment options within this field explores the uses of stem cells to provide optimal patient care. Within the stem cell field, there are many different types of stem cells and each has its different sources and implementations. There are totipotent stem cells that can differentiate into any of the 220 cell types of the body, including the placental cells. Embryonic cells in their early stages are totipotent. Pluripotent stem cells give rise to all cell types except placental cells and multipotent stem cells develop into a certain limited number of cell types.2 Stem cells can be further categorised depending on their source. Eg. Adult stem cells, also called tissue-specific stem cells, can differentiate into different cell types for the specific tissue they are extracted from.3 For example, stem cells in the bone marrow generate different blood cells but not other cells of the body. Mesenchymal stem cells, also called MSC, refers to cells isolated from the stroma which is the connective tissue surrounding tissues and organs. These were first discovered in the bone marrow and have capabilities to make bone, cartilage and fat cells.3 These stem cells may be a useful tool in restorative dentistry. Furthermore, induced pluripotent stem cells (iPS) are stem cells that have been engineered in the lab to behave like pluripotent stem cells.3 Extensive research is still taking place and what different properties these cells have and how these can be implemented. Stem cells have these fantastic uses to generate new cells but are these viable in restorative dentistry?
First, a clear idea of what restorative dentistry revolves around has to be explored so an idea can be formed on how stem cell treatment can be used to treat patients who want to receive restorative treatment. Restorative dentistry refers to a wide variety of treatments including crowns, bridges, fillings, veneers and more. These treatments provide functional restoration as well as cosmetic satisfaction for the patient. The important factors to consider are whether the treatments can be replaced by stem cell treatment and where the stem cells are obtained from.
For example, using stem cell treatment to provide treatment to patients for veneers wouldn’t be theoretically advantageous due to the nature of a veneer. A patient’s veneers have to be strong, thin, durable as well as aesthetic and there is no requirement to explore whether stem cells could be used for veneers as the current veneers available are highly successful and suitable for patients. There is no real requirement for stem cell research or other research to take place to explore other alternatives to veneers. On the other hand, a restorative procedure such as an implant may have better alternatives if stem cell research has developed and a method to ‘regrow’ cells is a viable option with benefits.
Another factor to consider involves the source of the stem cells. For instance, mesenchymal stem cells can be sourced from multiple parts of the body, like the bone marrow. Accessing stem cells is one of the limitations and ethical debates regarding the use but new sources are being discovered. For example, stem cells, whether they are utilised in restorative dentistry or not can be extracted from the dental pulp. Stem cells can also be extracted from human exfoliated deciduous teeth (SHED). These stem cells are from the same source as dental pulp stem cells but from primary teeth which will fall out by around the age of 12. One of the benefits of these cells is that they have been seen to have the capability to produce dentine and induce bone formation.4 Other stem cells that can be obtained from the oral cavity include periodontal ligament stem cells, root apical papilla stem cells and dental follicle stem cells. Obtaining stem cells from the oral cavity for treatment later also in the oral cavity is an advantage.
Within restorative dentistry, some possible benefits of using these stem cells from the oral cavity include the regeneration of periodontal tissue and the regeneration of dental pulp which would otherwise remain dead after root canal treatment.4 Furthermore, there are prospects to using non-dental stem cells for dental application including the use of urine to regrow teeth. 5 Researchers in China have harvested pluripotent stem cells derived from human urine and they were able to generate tooth-like structures. Even though large-scale testing has not been completed yet, the advantages of this include the low cost, non-invasive and the fact that these cells can be used rather than being ended up as waste. Also, these urine-derived stem cells do not form tumours in the body and rejection is highly unlikely. However, drawbacks include the fact that these generated teeth were only one third the hardness of normal human teeth.
One use of stem cells may be used as an alternative for root canal treatment. When dental fillings are required due to caries (cavity) being present, a dental professional will fill caries to prevent further tooth degradation and to protect the dental pulp. The dental pulp has to be protected to prevent pain and the eventual loss of the tooth. However, with severe caries, the pulp can be infected and root canal treatment has to take place to protect the tooth. A perfectly healthy tooth has had to undergo invasive treatment and will fall out quickly due to infection which may be avoided using stem cells. The same invasive procedure would occur but instead of filling with cement, stem cells can be utilised to stimulate the regrowth of dentine and pulp. In 2016, scientists at the University of Nottingham and Harvard University designed synthetic biomaterials to be used in conjunction with stem cells to encourage the new growth of cells within the dentine and pulp layer of the mouth. 6 This would allow patients to regrow teeth that have been damaged through dental disease and the tooth can remain healthy for a much longer period within the patient. Stem cells evidently provide an alternative treatment plan for a patient but whether this should be implemented more has to be evaluated.
Moreover, stem cell treatment may be an option in regards to a replacement for dental implants. Dental implants act as new teeth and tooth roots within a patient as old teeth may be extracted due to a variety of complications such as disease. These implants ensure the jaw bones and teeth structure in the mouth remains stable whilst allowing the patient to acquire cosmetic advantages. Overall, a patient’s satisfaction is improved with implants as comfort, speech, as well as appearance, are enhanced. 7 So why should stem cells be considered when dental implants are seen to be successful? Despite the great benefits seen, the disadvantages include that the healing process of implants can be very long. These implants are only pieces of titanium and cannot adapt to how the jaw grows. Also, careful cleaning and monitoring have to be completed to ensure that further infection does not occur. 8 As an alternative option that is being researched, the utilisation of stem cells may create a better solution to implants and whole teeth may be able to be regrown. At King’s College London, human gum tissue and stem cells from mice teeth were able to undergo tooth formation. 9 With whole tooth production possible outside the human body, these teeth may be able to be grown and used as natural implants. The advantage to this would involve a natural tooth within the mouth with its blood supply. But is this a safe option to go towards?
As this essay has explored, restorative dentistry encompasses a wide variety of treatments that patients can receive and stem cells do provide an alternative plan of action for a patient. Even though the whole of restorative dentistry is so vast, certain aspects may benefit from such research. The main benefits include the natural approach to providing care for a patient and allowing a patient to preserve their teeth for a longer duration of time. At the same time, all stem cell use would have to be researched thoroughly before its usage increases within the community but researchers and scientists are hopeful this can happen soon as the current research is pointing in the right direction. The current models of research are mainly confined to animal models and the current state of the likelihood of immune rejection within the oral cavity is not completely known.5 Despite the current risks that are unknown, with continued thorough research within this area the whole field of dentistry can be benefitted. Whilst being wary of the risks involved, the future of restorative dentistry seems highly promising and stem cell therapies could be a fantastic tool in dental practices.
References
- Bda.org. n.d. Restorative dentistry. [online] Available at: https://bda.org/careers/Salariedservices/Hospitaldentalservices/Pages/Restorativedentistry.aspx
- MacDonald, A., 2018. Cell Potency: Totipotent vs Pluripotent vs Multipotent Stem Cells. [online] Cell Science from Technology Networks. Available at: https://www.technologynetworks.com/cell-science/articles/cell-potency-totipotent-vs-pluripotent-vs-multipotent-stem-cells-303218
- A Closer Look at Stem Cells. n.d. Types of Stem Cells. [online] Available at: https://www.closerlookatstemcells.org/learn-about-stem-cells/types-of-stem-cells/.
- Ratan-NM and Pharm, M., 2020. Repairing Teeth using Stem Cells. [online] News-Medical.net. Available at: https://www.news-medical.net/health/Repairing-Teeth-using-Stem-Cells.aspx
- Jain, A. and Bansal, R., 2015. Current overview on dental stem cells applications in regenerative dentistry. [online] National Library of Medicine. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367063/
- Cuthberton, A., 2016. Dental fillings heal teeth with stem cells. [online] Newsweek. Available at: https://www.newsweek.com/dental-fillings-heal-teeth-stem-cells-harvard-cavities-477415
- Frisbee, E., 2021. Dental Implants. [online] WebMD. Available at: https://www.webmd.com/oral-health/guide/dental-implants
- Shapiro, J., 2022. What are Stem cell dental implants ?. [online] ismile.com. Available at: https://www.ismile.com/blog/stem-cell-dental-implants#:~:text=Stem%20cells%20are%20usually%20placed,used%20to%20regrow%20teeth%20completely
Excerpt:
This article explores how continued research within the area of stem cell treatment may change the way restorative dental treatments are carried out.
Youth Medical Journal 