Scientists aim to regrow teeth using stem cells- How 3D printing can build new bones

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 tissueand 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 cellsundifferentiated cells that turn into specialized onesthat 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.

Read more:
Scientists aim to regrow teeth using stem cells- How 3D printing can build new bones