Laser Therapy Prompts Regeneration in Teeth

NIH | JUNE 9, 2014

A small dose of low-power laser light activated dental stem cells in rat molars to generate dentin, one of the major components of teeth. The finding may lead to new approaches to develop low-cost, non-invasive therapies for treating dental disease and tooth damage.

Dentists currently use inert materials to repair damaged teeth. Tissue regeneration would be an attractive alternative, because inert materials can fail with time and don’t provide the full function of the tissue.

Stimulating regeneration of teeth, however, is a major challenge. Teeth are composed of several parts, including the pulp at the core, dentin in the middle, and enamel on the surface.

Stem cells, found throughout the body, can give rise to specialized cells. Researchers have been able to coax stem cells to transform (differentiate) into many types of cells in the laboratory before infusing them into the body. But these techniques are time consuming and can bring unwanted side effects.

Low-power laser (LPL) therapy has been used to treat inflammation and pain, and to stimulate wound healing, skin rejuvenation, and hair growth. LPL treatment has been noted to promote regeneration in cardiac, lung, and nerve tissues. These regenerative effects may be mediated through stem cells, but a direct link between laser treatment and stem cell biology hadn’t been clearly demonstrated.

A research team led by Dr. Praveen Arany of NIH’s National Institute of Dental and Craniofacial Research (NIDCR) and Dr. David Mooney at Harvard University set out to investigate whether LPL can induce stem cells to regenerate components in teeth.

The scientists first studied rats that had cavities in 2 molars, each with exposed tooth pulp (the soft inner part of the tooth). One tooth was treated with LPL, and the other wasn’t. Both damaged sites were then filled. The researchers found that dentin was induced in the LPL-treated molar after 12 weeks.

The team used laboratory cell lines to investigate how LPL induced dentin. They found that LPL treatment generated a type of molecule known as reactive oxygen species (ROS). ROS stimulated dentin production by activating transforming growth factor beta (TGF-β), a signaling protein that can promote dental stem cell differentiation.

The researchers also showed that LPL induced adult human dental stem cells to form dentin in the laboratory. Taken together, these results suggest that LPL might be used to direct stem cells in human teeth to regenerate dentin. Effective surgical techniques and optical focusing approaches would first need to be developed for the use of this treatment in people, however.

“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,” Mooney says. “It would be a substantial advance in the field if we can regenerate teeth rather than replace them.”

YOU MAY ALSO LIKE

New Clues to Universe's Structure Revealed

What is our universe made of, and has its composition changed over time? Scientists have new insights about these fundamental questions, thanks to an international collaboration of more than 400 scientists called the Dark Energy Survey (DES).

New Mechanism of Cell Movement Revealed

Cells in the human body often need to move in particular directions. Cell movement is crucial for embryo development, immune defense, and tissue repair and regeneration. It’s also key in cancer progression, as metastatic cells spread throughout the body.

Mysterious New Type of Human Brain Cell Discovered

A new type of human brain cell was discovered by Scientists that has never been seen in mice and other well-studied laboratory animals before.

"Mini Supernova" Explosion Could Have Big Impact

Using NASA’s Chandra X-ray Observatory, astronomers have studied one particular explosion that may provide clues to the dynamics of other, much larger stellar eruptions.

Coral reefs shifting away from equatorial waters

Coral reefs are retreating from equatorial waters and establishing new reefs in more temperate regions.

No limit to life in deep sediment of ocean's "deadest" region

Scientists have found oxygen and oxygen-breathing microbes all the way through the sediment from the seafloor to the igneous basement at seven sites in the South Pacific gyre, considered the "deadest" location in the ocean.