http://www.dentistryiq.com/index/display/article-display/0045494294/articles/dentisryiq/industry/2010/05/body_s-stem_cells.html

People who have lost some or all of their adult teeth typically look to dentures, or more recently, dental implants to bridge the gap between a toothless appearance.

But this appearance can have a host of unsettling psycho-social ramifications and a tooth-filled grin that is not without pain and discomfort.

Despite being the preferred treatment for missing teeth today, dental implants can fail and have no ability to “remodel” with surrounding jaw bone, which undergoes necessary and unavoidable changes throughout a person’s life.

But a new technique pioneered in the Tissue Engineering and Regenerative Medicine Laboratory of Dr. Jeremy Mao, Edward V. Zegarelli Professor of Dental Medicine, and a professor of biomedical engineering at Columbia University, can orchestrate the body’s stem cells to migrate to three-dimensional scaffold that is infused with growth factor. This can yield an anatomically correct tooth in as soon as nine weeks once implanted in the mouth.

“These findings represent the first report of regeneration of anatomically shaped tooth-like structures in vivo, and by cell homing without cell delivery,” Dr. Mao and his colleagues said in the paper.

“The potency of cell homing is substantiated not only by cell recruitment into scaffold microchannels, but also by regeneration of a putative periodontal ligaments newly formed alveolar bone.”

Dental implants usually consist of a cone-shaped titanium screw with a roughened or smooth surface and are placed in the jaw bone. While implant surgery may be performed as an outpatient procedure, healing times vary widely and successful implantation is a result of multiple visits to certified clinicians, including general dentists, oral surgeons, prosthodontists and periodontists.

Implant patients must allow two to six months for healing and if the implant is installed too soon, it is possible that the implant may move which results in failure. The subsequent time to heal, graft and eventually place a new implant may take up to 18 months.

The work of Dr. Mao and his laboratory, however, holds manifold promise: a more natural process, faster recovery times, and a harnessing of the body’s potential to regrow tissue that will not give out and could ultimately last the patient’s lifetime.

By homing stem cells to a scaffold made of natural materials and integrated in surrounding tissue, there is no need to use harvested stem cell lines, or create a an environment outside of the body (e.g., a Petri dish) where the tooth is grown and then implanted once it has matured.

The tooth instead can be grown “orthotopically,” or in the socket where the tooth will integrate with surrounding tissue in ways that are impossible with hard metals or other materials.

“A key consideration in tooth regeneration is finding a cost-effective approach that can translate into therapies for patients who cannot afford or who aren’t good candidates for dental implants,” Dr. Mao said. “Cell-homing-based tooth regeneration may provide a tangible pathway toward clinical translation.”

This study is published in the Journal of Dental Research, a top journal in the field of dentistry.

This research was supported by NIH ARRA Funding via 5RC2 DE020767 from the National Institute of Dental and Craniofacial Research.

May 13 2010 (Dentistry IQ)