Category Archives: Teeth

No more root canals? Scientists aim to regrow teeth using stem cells

Dental Could the days of the root canal, for decades the symbol of the most excruciating kind of minor surgery, finally be numbered?

Scientists have made advances in treating tooth decay that they hope will let them restore tooth tissue—and avoid the painful dental procedure. Several recent studies have demonstrated in animals that procedures involving tooth stem cells appear to regrow the critical, living tooth tissue known as pulp.

Treatments that prompt the body to regrow its own tissues and organs are known broadly as regenerative medicine. There is significant interest in figuring out how to implement this knowledge to help the many people with cavities and disease that lead to tooth loss.

In the U.S., half of kids have had at least one cavity by the time they are 15 years old and a quarter of adults over the age of 65 have lost all of their teeth, according to the Centers for Disease Control and Prevention. An estimated $108 billion was spent on dental services in 2010, including elective and out-of-pocket care, according to the CDC.

Tooth decay arises when bacteria or infections overwhelm a tooth’s natural repair process. If the culprit isn’t reduced or eliminated, the damage can continue. If it erodes the hard, outer enamel and penetrates down inside the tooth, the infection eventually can kill the soft pulp tissue inside, prompting the need for either a root canal or removal of the tooth. Pulp is necessary to detecting sensation, including heat, cold and pressure, and contains the stem cells—undifferentiated cells that turn into specialized ones—that can regenerate tooth tissue.

Researchers from South Korea and Japan to the U.S. and United Kingdom have been working on how to coax stem cells into regenerating pulp. The process is still in its early stages, but if successful, it could mean a reduction or even elimination of the need for painful root canals.

While much of the work has shown promise in the lab and in early work in animals, including dogs, there have only been a few reports of experiments in humans.

The root-canal procedure involves cleaning out the infected and dead tissue in the root canal of the tooth, disinfecting the area and adding an impermeable seal to try to prevent further infection.

But the seal does not always prevent new infection. While the affected tooth remains in the mouth, it is essentially dead, which could impact functions like chewing. That also means no living nerves remain in the tooth to detect further decay or infection. Infection could subsequently spread to surrounding tissue without detection. An estimated 15.1 million root canals are performed in the U.S. annually, according to a 2005-06 survey by the American Dental Association, the most recent data available.

“The whole concept of going for pulp regeneration is that you will try and retain a vital tooth, a tooth that is alive,” says Tony Smith, a professor in oral biology at the University of Birmingham in the U.K. “That means the tooth’s natural defense mechanisms will still be there.

“I think we are really just at the opening stages of what is going to be a very exciting time, because we’re moving away from traditional root-canal treatments.”

Some scientists have focused on growing entirely new teeth. More are focused on trying to grow healthy new pulp inside the hard shell of tooth enamel, either by stimulating or encouraging stem cells or by better controlling the inflammation that goes on in the mouth in response to an infection.

Some of the challenges with making new teeth are generating not just the right tissue but also the right structure, as well as how to place the tooth or the new pulp in the mouth, according to Rena D’Souza, a professor of biomedical sciences at Baylor College of Dentistry. Beyond anti-inflammatory medication, options for tackling the infection while the new treatments work are limited. And, as with stem-cell research efforts with other body parts, successfully regenerating dental tissue in the lab or another animal doesn’t mean it will work in a human body.

Dental stem cells can be harvested from the pulp tissue of the wisdom and other types of adult teeth, or baby teeth. They can produce both the hard tissues needed by the tooth, like bone, and soft tissues like the pulp, says Dr. D’Souza, a former president of the American Association for Dental Research who will become the dean of the University of Utah’s School of Dental Medicine Aug. 1.

She and colleagues at Baylor and Rice University focused on regrowing pulp using a small protein hydrogel. The gelatin-like substance is injected into the tooth and serves as a base into which pulp cells, blood vessels and nerves grow.

In a study published in November, they were able to demonstrate pulp regeneration in human teeth in a lab. They will soon be testing hydrogel on live dogs. In addition, they are looking at the potential of the hydrogel to calm dental inflammation.

Source: http://www.foxnews.com, Smarter America, The Wall Street Journal


Teeth ‘transform into liver cells’

 The compound that causes bad breath could help fuel the development of stem cells from dental pulp, according to a study.

Hydrogen sulphide (H2S) – which has the characteristic smell of rotten eggs – appears to help teeth stem cells transform into liver cells, which could prove a valuable treatment for patients, researchers found.

H2S is a major cause of halitosis or bad breath, which is of concern to millions of people worldwide.

A team of experts took stem cells from dental pulp – the central part of the tooth made up of connective tissue and cells – obtained from the teeth of dental patients undergoing routine tooth extractions.

The cells were separated into two groups, with one group incubated in a H2S chamber and the other group acting as a control. The cells were analysed after three, six and nine days to see if they had transformed into liver cells. Their ability to function as liver cells was also tested, including the ability to store glycogen and collect urea.

The study, published in the Journal of Breath Research, from the Institute of Physics, suggested liver cells could be produced in high numbers of high purity.

Lead author of the study, Dr Ken Yaegaki, from Nippon Dental University in Japan, said: “High purity means there are less ‘wrong cells’ that are being differentiated to other tissues, or remaining as stem cells. Moreover, these facts suggest that patients undergoing transplantation with the hepatic (liver) cells may have almost no possibility of developing teratomas (tumours) or cancers.

“Until now, nobody has produced the protocol to regenerate such a huge number of hepatic cells for human transplantation. Compared to the traditional method of using fetal bovine serum to produce the cells, our method is productive and, most importantly, safe.”

Professor Anthony Hollander, head of cellular and molecular medicine at Bristol University, said much more research was needed.

He said: “This is interesting work in a new direction but there’s a long way to go to see if it is usable therapeutically. This is potential evidence but the real test of the liver cell is whether it metabolises specific toxins,” he said, adding that that requires enzyme function tests.”

 

Source: The Press Association


Teeth Stem Cells from Pups Grow Bone in Parents

September 26, 2011 — Stem cells derived from deciduous canine teeth and dental pulp can be grafted and produce bone regeneration between parents and offspring, according to a study in Cell Transplantation (2011, Vol. 20:7, pp. 1003-1013).

“Bone defects can occur for a number of reasons, and autogenous bone grafting — using the patient’s own bone — has been a standard approach to treatment,” stated study author Yoichi Yamada, DDS, PhD, of the Center for Genetic and Regenerative Medicine at the Nagoya University School of Medicine, in a press release. “However, considering severe invasiveness in self-donor bone sites and the limited supply of autogenous bone, alternative donor sources are needed.”

Previous studies have shown that oral and maxillofacial dental tissues contain a variety of stem cells, such as dental pulp stem cells and stem cells from deciduous teeth, Dr. Yamada and his colleagues noted.

Stem cells from human exfoliated deciduous teeth were identified as a novel population of stem cells, capable of differentiating into various cell types, such as osteoblasts, odontoblasts, adipocytes, and neural cells,” Dr. Yamada explained.

Their study extracted deciduous teeth from canine puppies and grafted them onto parent canine mandibles as an allograft. After four weeks, bone defects were prepared on both sides of the host mandible. The newly formed bone was evaluated at two, four, and eight weeks. When compared with controls, the study group demonstrated well-formed mature bone and neovascularization.

Stem cells derived from dental pulp “display increased immunosuppressive activity when compared to bone marrow mesenchymal cells” and will likely have “immunosuppressive activity with potential clinical applications in allogenic in vivo stem cell transplantation, particularly for calcified tissue reconstruction,” the study authors noted.

This preclinical study could pave the way for stem cell therapy in orthopedics and oral and maxillofacial reconstruction, Dr. Yamada concluded.

Via DrBicuspid.com


Stem Cells from Teeth?

I found a company called RenovoCyte and they’re doing some interesting things with teeth!

Renovocyte helps put the power of stem cell therapy for regenerative medicine in your hands.

It is now well known that umbilical cord blood is a rich source of blood and immune system forming stem cells. Cord blood stem cell banks can provide an invaluable service to those afflicted with leukemia and immune disorders*. The American Academy of Pediatrics (AAP) encourages families to donate their newborn’s cord blood, which is normally discarded at birth, to cord blood banks (if accessible in their area) for use by other individuals in need, and while the AAP does recommend private cord blood banking for parents who have an older child with a condition that could potentially benefit from transplantation, such as a genetic immunodeficiency, storing cord blood at private banks for later personal or family use as a general “insurance policy” is discouraged. The chances of a child needing his or her own cord blood stem cells in the future are estimated to range from one in 1,000 to one in 200,000.

Why tooth stem cells?

Recent studies investigating dental pulp have indicated the presence of an exciting new source of non controversial stem cells. These studies have indicated that these cells may have the potential to be utilized in stem cell mediated therapies as well as tissue engineering applications. Unlike the stem cells typically derived from umbilical cord blood, which are usually used to replace bone marrow, these tooth derived “multipotent mesenchymal stromal cells” (MSC) or “tissue stem cells” appear to be able to develop into many different tissues including, bone, cartilage and even neural tissue. Also, unlike umbilical cord blood derived cells, these stem cells are of greatest potential benefit to the original donor, and can be expanded in the laboratory to create many available doses. To allow potential therapeutic use of these cells, Renovocyte, LLC was developed to capitalize on our group’s unique understanding and experience with this material, specifically with respect to processing, preservation and storage. While cells can be recovered from exfoliated or “baby” teeth, this procedure is very inefficient. The most efficient source of tooth stem cells is extracted 3rd molars or “wisdom teeth”. Our optimized processing method allows for efficient recovery of stem cells from fresh tissue which can then be tested for safety and purity and cryopreserved, and then expanded and used many times as needed for future procedures. Our group developed these procedures through National Institutes of Health grants1 and our methods have been published in peer reviewed scientific journals2,3.
Renovocyte’s services are extremely easy to use. The stem cells come from teeth that are otherwise being extracted, so there is no extra procedure involved. This means dental stem cell banking is one of least expensive and noninvasive ways to access and bank your own stem cells for future use.

*for private umbilical cord blood banking, please visit www.thegenesisbank.com.