Harvard invents tooth re-growth that could fix cavities
SUMMARY: Harvard engineers discovered a way to re-grow a tooth using laser light therapy, which could erase the need for root canals.
Posted: May 29, 2014
Leave it to Harvard University scientists to invent a technology that allows a tooth to re-grow itself, potentially remedying cavities and erasing root canals forever.
Researchers claim they discovered a new method to rebuild parts of teeth using focused laser light therapy, according to the study published in the journal Science Translational Medicine. By shining the low-powered laser at the same level of brightness of a sunlit day, Harvard engineer David Mooney and colleagues were able to stimulate the growth of lost dentin, the calcified tissue inside a tooth. So far, they have only successfully accomplished this with rodents, but the possibility of trying it on humans is a very close and reachable goal, the study authors said.
Root canals are a troublesome issue brought on by tooth decay, which may be signaled by aches and bad breath.
The power protein
The procedure centers around a native protein called transforming growth factor beta, or TGF-beta. In the initial tests of dental tissue, this growth factor changed dramatically when it met a focused beam of light. Further analysis unveiled that the TGF-beta in fact stimulated the stem cells already present in dentin.
Mooney pointed out that the power of the laser must be at a specific intensity level and cannot emit any heat to be effective. At very low frequencies, laser light does nothing, and at higher frequencies, it is commonly used to cut and cauterize tissue, so the dose of light has to be meticulously delivered. In short, too little won't do enough and too much could be destructive.
When it's just right, the light appears to stimulate a chemical reaction that releases oxygen species, which in turn, activates TGF-beta. This protein plays an essential part in embryonic development and wound healing. By kick-starting this cascade of events, Mooney and lead researcher Praveen Arany exhibited that they can produce dentin by shining the laser on a rodent's tooth.
"Once [TGF-beta] is activated by the laser, it can bind to stem cells resident in the tissue, and then it induces those stem cells to differentiate so they can proliferate and reform dentin," David Mooney, the Pinkas Family Professor of Bioengineering at Harvard University, told Fox News.
Eliminating root canals
In a clinical setting, there might not be a future need for drilling and filling of a root canal. When you get a cavity and don't do anything about it, the nerve can become infected or the pulp damaged. So, during a typical root canal treatment, the nerve and pulp are removed, and the inside of the tooth is cleaned and sealed.
Mooney noted that focused laser therapy could be applied to grow more protective dentin in teeth that have become sensitive due to gum recession. This may be a sign of gingivitis, or early stage gum disease.
But with laser technology, patients and dentists might be able to say goodbye to root canals.
Although Mooney hasn't spurred the growth of an entire tooth yet because the new dentin lacks the tooth's structure, he is optimistic that there is a way to get the body to rebuild other structures, too.
Mooney's work opens up a number of biomedical possibilities, according to Harold Slavkin, a molecular biologist and professor of dentistry at the Ostrow School of Dentistry at the University of Southern California in Los Angeles. Mooney's work has the potential to eventually allow people to re-grow their own livers, kidneys or hearts, revolutionizing medical care, he said.
"Twenty or 30 years from now people may say, 'Isn't it ridiculous that they used to transplant organs from one person to the other,'" Slavkin said.