You are hereJune 17, 2013
Are root canals headed for obscurity? Stem cell study indicates maybe so
“Dental cavities and inflammation of the surrounding pulp is a challenging public health issue, as tooth decay not only can cause a patient great pain but it also can lead to other serious health issues including heart disease,” explained Misako Nakashima, DDS, Ph.D., of the National Center for Geriatrics and Gerontology in Obu, Japan. “Generally we treat deep cavities by capping the tooth and removing any inflamed pulp surrounding it. But this has limited success and the problem frequently progresses until the tooth must be removed.”
In this newest study, conducted by Dr. Nakashima and several of her NCGG colleagues along with scientists from Shin Nippon Biomedical Laboratories in Kagoshima and from the School of Dentistry at Aichi-gakuin University in Nagoya, the goal was to test a stem cell-based therapy that would regenerate the dentin-pulp complex and, consequently, totally restore the tooth’s structure and function. At the same time, they wanted to assess the safety of pulp stem cell transplantation in humans as a prelude to upcoming clinical trials.
They began by performing root canals on a group of 18 dogs, collecting the pulp stem cells and then treating them in the lab with a growth factor called granulocyte-colony stimulating factor (G-CSF). They then transplanted the treated cells back in the dogs, with each animal receiving its own cells to reduce the chance of rejection.
“Other studies demonstrated the therapeutic effects and safety of mesenchymal stem cells (MSCs) for various diseases. There have been no preclinical reports, however, to support the use of pulp stem cells as a potential treatment for pulpitis in clinical trials,” Dr. Nakashima said. “We also knew that previous studies involving the spinal cord show that combining G-CSF with stem cells derived from other types of tissues, bone marrow stromal cells, neuronal stem cells and amniotic fluid stem cells had several benefits. So we reasoned that G-CSF might positively impact the pulp stem cells, too.”
When they examined the results, which included comparing the G-CSF treated cells to a control group of non-treated cells, they found the cells did indeed regenerate the pulp tissue and completely filled in the dogs’ root canals.
“We also noted that the pulp stem cells treated with G-CSF yielded a significantly larger amount of regenerated dentin-pulp complex than those without it,” Dr. Nakashima observed. “Also noteworthy was the reduced number of inflammatory cells, the decrease in cell death and the significant increase in neurite outgrowth (the projections that transfer a cell’s impulses compared to those without G-CSF). Furthermore, there was no evidence of toxicity or adverse events.”
Based on these preclinical results of efficacy and safety, a clinical trial of pulp regeneration has already been initiated with the permission of the Japanese Ministry of Health, Labor and Welfare, she added.
“This first preclinical demonstration of the efficacy and safety after transplantation of clinical-grade pulp stem cells together with G-CSF for dentin-pulp regeneration is very encouraging,” said Anthony Atala, M.D., Editor of STEM CELLS Translational Medicine and director of the Wake Forest Institute for Regenerative Medicine.
The Wall Street Journal: To Avoid Root Canals, Teeth That Replace Themselves