July 11, 2004
Periodontal Ligament Stem Cell Type Found In Wisdom Teeth

Working with freshly extracted human third molars (wisdom teeth) scientists have been able to isolate stem cells that can turn into the ligament that hold teeth into place.

Scientists at the National Institute of Dental and Craniofacial Research (NIDCR), one of the National Institutes of Health, and their colleagues have isolated human postnatal stem cells for the first time directly from the periodontal ligament, the fibrous, net-like tendon that holds our teeth in their sockets.

The scientists also say these cells have "tremendous potential" to regenerate the periodontal ligament, a common target of advanced gum (periodontal) disease. This enthusiasm is based on follow up experiments, in which the researchers implanted the human adult stem cells into rodents, and most of the cells differentiated into a mixture of periodontal ligament — including the specific fiber bundles that attach tooth to bone — and the mineralized tissue called cementum that covers the roots of our teeth.

"The stem cells produced beautifully dense, regenerated tissue in the animals," said Dr. Songtao Shi, a senior author on the paper and an NIDCR scientist. "That was when we knew they had great potential one day as a treatment for periodontal disease, and we're continuing to follow up on this promise with additional animal work." The results are published in the current issue of The Lancet.

The isolated cells were able to form periodontal ligament.

After further validation of their findings, Shi said he and his colleagues decided to pursue the next big question: Could these stem cells actually form periodontal ligament and cementum when transplanted into mice?

Of the 13 transplants — each of which was derived from a distinct colony of stem cells cultured in the laboratory and loaded into a hydroxyapetite carrier — eight produced a dense mixture of cementum and periodontal ligament. Interestingly, the cells even produced fibrous structures similar to the so-called Sharpey's fibers, which insert into both cementum and bone to hold teeth in place. The other five transplants showed no signs of differentiation.

Shi said his group is now following up on this finding in larger animals. If successful, Shi said he would be eager to evaluate their regenerative ability in people with advanced periodontal disease, which can be extremely difficult to control with current treatments.

My guess is they want to extract similar cells from large non-human animals because for ethical and practical reasons it is easier to do most of the work toward developing therapies using animals before attempting trials in humans.

While the press release has just been released to announce the publishing of the results in Lancet it appears this work was done last year, a patent has already been filed on it, and the final confirming step involved putting the human cells into immunicompromised mice to form the specialized ligament cells.

The NIH announces a new technology wherein stem cells from the PDL have been isolated from adult human PDL. These cells are capable of forming cementum and PDL in immunocompromised mice. In cell culture, PDL stem cells differentiate into collagen fiber forming cells (fibroblasts), cementoblasts, and adipocytes. It is anticipated that these PDL stem cells will be useful for periodontal tissue regeneration to treat periodontal disease.

It is hard to guess when this work will translate into wide availability of human treatments. But the consensus of German stem cell researchers is that some stem cell therapies will be available within 10 years.

My guess is that there are many more sources of adult stem cells hiding in various locations of the human body waiting to be found. Expect to read many more reports of discoveries of types of adult stem cells. Each such discovery is helpful not just as a potential starting source of cells for cell thearpies but also to compare to other cell types to develop a better understanding of how cells differentiate. The more cell types scientists have to compare the better they will be able to figure out how cells control their cell types and how to intervene to alter cell types for therapeutic purposes.

Share |      Randall Parker, 2004 July 11 04:51 PM  Biotech Organ Replacement

Fly said at July 11, 2004 6:29 PM:

“My guess is that there are many more sources of adult stem cells hiding in various locations of the human body waiting to be found.”

I agree. Here is a reference to the first identification of skin stem cells:

It makes a couple of interesting observations. Less than 1% of the cells were stem cells. They had no visible markers for distinguishing stem cells from other skin cells. That made it very hard to isolate the stem cells.

As more stem cells are identified, more knowledge will be gained as to how stem cells differ from other cells and what signals trigger growth and differentiation.

Zaw Moe Lwin said at August 1, 2004 3:56 AM:

I think we can make tooth transplant with tusk of elephent or lab made tooth which can be attached by PL

Mark Rutter said at September 12, 2004 4:40 PM:

on the Growing teeth from stem sell project, Will they be taking volunters to be the first human subjects.
because I would like to volunteer

paddy said at June 2, 2005 12:22 PM:

I hope the research into growing your own teeth becomes reality.I wouldn't mind what the cost was i'd definately have it done

Karen said at July 6, 2005 3:42 PM:

I heard that if and when it does come out it will cost an arm and a leg! Your insurance may not cover the cost :-(.

10 years is a long wait! We must look after our teeth as gold (which they are to our health!)

aravind said at July 17, 2005 8:58 AM:

sir, i am doing a study on periodontal manifestations in chronic renal failure patients and iam short of reference articles so i kindly request you to forward me some articles which wloud be of a great help to me in my study. please as i am a postgraduate student and i cannot afford to buy the articles.

thanking you
yours sincerely
aravind kumar.p

Karen said at July 30, 2005 1:24 PM:

Please see

its on the same topic but the thread is more active!

Kimberly S. DeMonaco said at August 14, 2006 6:21 PM:

I am an instructor at Nova Southeastern College of Dental Medicine.

It is my goal to one day be on a research team that is developing ways to grow teeth.

I have been a Registered Dental Hygienist for almost 18 years and started my studies in the dental field over 21 years ago (1984). Interestingly, I have been dreaming of an opportunity to "grow teeth", and to take these advancements to third world countries, where thousands of people are suffering from poor digestion, due to not being able to properly masticate their food, due to not having teeth.

Yes, it is far fetched. Yet, if we can send food to other countries, wouldn't it be important that we also make sure that they could eat the food we send.

Kimberly S. DeMonaco, R.D.H. Coordinator/Instructor in Periodontology

jessica said at March 29, 2007 12:18 PM:

does anyone know where I can donate my wisdom teeth? I am getting them out in August 07, and read this.

Sarah Clayton said at October 3, 2007 4:22 AM:

I too would be very willing to volunteer for the first trials on Humans to grow new teeth. Periodontal disease is so very distressing and I have lost teeth even though there has been nothing wrong with the actual tooth. So please, please, please consider my offer to be a human trial participant.

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