Dental Stem Cells: Regenerating Instead of Restoring?

Austin Yan, Emory University

Introduction

Stem cells, commonly associated with molecular medicine for their potential to replace damaged cells or organs in terminal diseases like leukemia, have often been overlooked in reconstructive dentistry. However, this perception changed when Dr. Yingzi Yang and Dr. Jennifer Gibbs of Harvard University embarked on groundbreaking research to discover a specific type of stem cell capable of repairing damaged dentin.

In the realm of regenerative medicine, dental stem cells have risen as a promising and valuable resource. These remarkable cells possess the remarkable ability to differentiate into various tissues, presenting the potential to revolutionize medical treatments as we know them.

What are Dental Stem Cells?

Stem cells, in general, can develop in many different cell types in the body, essentially acting as the body's natural repair system. When it comes to dental stem cells specifically, they reside in the dental tissue and can be conveniently collected through a non-invasive procedure. Typically, dental stem cells are collected from wisdom teeth during extraction, baby teeth when they fall out, and permanent teeth during root canal treatment. This non-invasive nature of dental stem cell collection eliminates the controversial issues often associated with the retrieval of embryonic stem cells.

Just like other stem cells, there are numerous types of stem cells: 

1. Dental Pulp Stem Cells (DPSC): Dental pulp stem cells are mainly located within the pulp cavity of impacted third molars. For the cells to be collected, they are carefully isolated from adult third molars obtained during the extraction of a donor's 'wisdom' teeth. These cells naturally serve the purpose of producing odontoblasts, whose main function is to create dentin, making them highly valuable for reconstructive dentistry and regeneration of tooth structures. 

2. Stem Cells from Human Exfoliated Deciduous Teeth (SHED): SHED are highly proliferative pluripotent cells can be readily retrieved from the primary teeth of children. Unlike pulp stem cells, their differentiation potential extends beyond odontoblasts, allowing them to induce bone formation, generate dentin, and exhibit remarkable survival capabilities. This opens new possibilities for therapeutic applications targeting tissue repair and regeneration.

3. Periodontal Ligament Stem Cells (PDLSC): Periodontal tissue stem cells, residing in the periodontal ligament (PDL), hold a vital responsibility in preserving the homeostasis of periodontal tissues. Remarkably, these cells exhibit mesenchymal stem cell characteristics akin to bone marrow stem cells, enabling them to facilitate the repair of skeletal tissue. Given their unique attributes, these stem cells represent a highly promising resource for periodontal regeneration, offering new hope for improved treatments and therapies in the field of periodontics.

Challenges and Future Prospects

While dental stem cells hold tremendous potential, they still face significant obstacles. The field of stem cell research is still emerging, leaving many aspects shrouded in uncertainty, thereby eliciting fear among patients. Simultaneously, a cell-free approach is still favored mainly for its simplicity and its track record of success. 

Another challenge is where to get dental stem cells. In most studies, healthy dental tissue serves as the source of extracted stem cells used in treatment. However, dentists will not have this luxury in clinics, instead resorting to additional surgical procedures, such as wisdom teeth extraction. Doing so might actually exacerbate patient discomfort. A solution to this is to harvest stem cells from inflamed dental tissue. The problem with this approach lies in questions regarding the stem cell's functional capabilities within an inflammatory environment.

Future Steps

Undoubtedly, the future of dental stem cells in regenerative dental medicine shines with promise. While there are current challenges surrounding how to extract dental stem cells, they are expected to be overcome through ongoing research and time. 

Currently, the potential applications and benefits of dental stem cells in regenerating dental tissue, bone, and nerve function hold the power to revolutionize all aspects of dentistry. This integration of stem cells into dental practices has the potential to transform reconstructive dentistry into a realm of regenerative possibilities.

Welcome to the age of regenerative dental medicine —a realm where stem cells hold the power to regenerate and restore.