Stem Cells and Dental Implants

by Blake Nicolucci, BSc, DDS

I’ve been wondering what could possibly become the next evolution in dental implantology. At present, most dental implant companies have been flogging the same materials, shapes, and coatings and then simply putting their name on the ‘new’ product. The growth in the number of implant companies in recent years has created greater competition and lower market prices for the dentist. But to excel it is not enough to just be competitive in the market. There must be more research and innovation for a company to remain viable, desirable and ‘ahead of the curve’.

Stem cell research is not a new medical entity by any means. There has been extensive research for many years now in the areas of orthopedics, cardiology, neurology and internal medicine. It has only been recently that the dental field has taken a harder look at stem cells and their use not only in promoting more predictable bone grafting but in the reconstruction of the entire dental follicle. Before this, research on stem cells was being concentrated on the healing of diseased and/or traumatized tissues and organs. More recently, stem cells have been used to grow complete and functional organs such as hearts (in mice) and are now being used in an experimental basis to repair heart muscle in human patients who have had massive heart attacks. They are trying to regenerate the dead portion of the ventricular muscle back from its ‘scar tissue’ state (a result of blood loss after blockage of the LAD artery) to a healed and normal functioning muscle. This therapy is now in clinical trials in Kentucky and California, but it shouldn’t be too long before it is established as a viable medical procedure. Toronto has now started a cardiac stem cell program of its own. In the U.S. studies, stem cells are harvested from the septum of the heart (between the atria) and are therefore already in a ‘cardiac ready’ mode to reproduce cells. These cells are then injected around the scar tissue in the ventricle in some 12 to 15 circumferential positions. The results have been very promising with some patients reportedly having an increased cardiac ‘ejection fraction’ of up to 50% so that a person with an ejection fraction of 20% could increase their fraction to 30%.

All of this new medical research has stimulated the ‘dental research community’ to investigate tooth reproduction from stem cells even further. Replacement of the entire tooth (root, crown, pulp, and periodontal structures) has become the focus of research by some of the more ‘state of the art’ companies who might be afraid that the standard ‘titanium dental implants’ will become obsolete in the future. Researchers from the Institute of Biotechnology at the University of Helsinki have had overwhelming success in the process of generating teeth in mammals, and it will only be a short time before this is established in humans — (please understand that a “short time” in research standards can translate into decades for you and I).

The process of producing a tooth is very complex and has many different aspects. As such, there are many different approaches taken by the different researchers and research facilities. Stem cells have been extracted from bone marrow and have been found to have osteogenic precursors. These mesenchymal progenitor cells have the potential to differentiate into multiple tissue types such as bone, cartilage, adipose tissue, connective tissue and skeletal muscle.

The statement “control of morphogenesis and cyto-differentiation is a challenge” to me is an understatement. I tip my hat to all of the researchers who have taken it upon themselves to investigate the ‘regeneration’ of teeth in humans. At Columbia University Medical Center, Dr. Jeremy Mao is researching a technique in which growth-factor covered ‘three-dimensional scaffolding’ is being used to act as a ‘cell-homing’ device. This ‘mesh’ shaped tooth is implanted into the host tissue, and within nine weeks, significant growth and maturation has occurred. This has been accomplished outside the body (in a Petri dish) and in vivo. Once formation has been completed outside the body, they are then able to transplant the structure to a specific site in the jaw.

What does this mean to me and my practice today? I hope you realize that this is the future of dental implantology. Onward and upward! Progress! Dental implants have been a major part of my life for over 30 years now. This atypical research and development has intrigued me since its inception, and if you are involved in implant dentistry, then you too should be aware of these facts, since this will impact us all in some way in the future! I hope that during my lifetime I will be a part of this new world of dental implants and be able to use stem cells to replace missing teeth in my patients. This is really — “an exciting frontier!” OH