Researchers Repair Rodent Teeth using Lasers

Harvard University scientists use light to coax stem cells to regrow parts of teeth.

The study was conducted by Harvard School of Engineering and Applied Sciences (SEAS) researchers and colleagues. The team is optimistic that someday bones and tissues could be repaired by just zapping it with lasers.

Several researchers are trying to find a way to regenerate tissues and organs in the lab using stem cells. What's unique in the study is that researchers didn't take the cells out of the body, meaning that there is no danger of introducing any foreign material along with the regenerated tissue.

"Our treatment modality does not introduce anything new to the body, and lasers are routinely used in medicine and dentistry, so the barriers to clinical translation are low," said David J. Mooney, lead author of the study. "It would be a substantial advance in the field if we can regenerate teeth rather than replace them."

Rodent Dentistry

In the study, researchers focussed on creating dentin - the hard tissue in teeth - using human dental stem cells.

The study was conducted on rodent models. Researchers collaborated with dentist Praveen Arany, Ph.D., at the National Institutes of Health (NIH) to perform complicated dental procedures in the test animals.

Arany created holes in the molars of the rodents, used lasers to trigger growth in the tooth pulp and sealed the teeth with temporary caps.

About 12 weeks after the procedure, the rodents had developed new tissues that filled the holes in the teeth. The team confirmed that the high-resolution x-ray imaging and microscopy triggered dentin formation.

The regenerated dentin was similar to normal dentin, but had slightly different morphological organization, researchers said.

The team then conducted lab tests to see the molecular mechanism behind the tissue regeneration. They found that a cell protein called transforming growth factor beta-1 (TGF-β1) was linked with the regrowth. TGF-β1 is present in all living cells.

According to the researchers, the laser creates reactive oxygen species (ROS). The ROS activates the TGF-β1complex. The activated protein then differentiates the stem cells into dentin, researchers said in a news release.

In the next part of the study, researchers will conduct clinical trials to see if lasers can repair teeth in humans.

The study is published in the journal Science Translational Medicine.