In what could be the most important advance in oral health since the invention of the toothbrush, scientists at the Forsyth Institute (Boston) are developing a hand-held, light-based device that might, one day, be used by consumers to help combat periodontal disease.
Researchers from the non-profit research organization focused on oral, craniofacial and related biomedical science, have found that blue light can be used to selectively suppress certain bacteria associated with destructive gum disease.
The research, published in the April issue of the Journal of Antimicrobial Agents and Chemotherapy, suggests that light in the blue region of the visible spectrum might be useful in preventing, controlling or treating periodontitis, an oral infection that can lead to loss of bone and teeth.
Though still in its very earliest stages of development – the institute is seeking funding to take its R&D into clinical trials – the hope would be that such a device could be used in a preventive mode against periodontitis, said Forsyth’s Director of Clinical Research Max Goodson, DDS, PhD.
Goodson envisions such a device as being “like a toothbrush with a very intense light on it.” He told Medical Device Daily: “Our thought would be that it would be available as a take-home device, like a toothbrush. Our theory is that if people have low-dose applications of light everyday, then they will be able to keep bacteria [the underlying cause of gum disease] down to a level that is below the level that they are harmful.”
If proved effective in clinical trials, the toothbrush-like device could be another tool in the arsenal against gum disease. “Obviously it would be most beneficial for those who have the highest risk for progressing or demonstrating periodontitis, but my general feeling is that it could be beneficial to virtually everyone,” Goodson said. “The wonderful thing about it is that in so far as we know, this type of therapy has no side effects. We’re not giving drugs or anything else, we’re just exposing the bacteria to light.”
In the current research, Goodson’s team used a halogen lamp source to shine broadband light (380nm to 520nm wavelengths) on pure cultures of black-pigmented bacteria (BPB) – one of the most destructive oral bacteria – and on dental plaque samples obtained from individuals with chronic periodontitis.
The researchers found that light rapidly killed BPB in pure cultures and that it selectively eliminated BPB in plaque samples containing more than 500 different bacteria. They also found that varying the intensity of light and exposure time had different impacts on different species, and that when the proportion of such pathogens was reduced, the proportion of other, potentially helpful, bacteria increased.
“What this initial publication essentially showed is that the majority of bacteria that were being affected had high levels of porphyrin, and that the amount of porphyrin that the bacteria had within the body seemed to be directly related to the effectiveness of the light in terms of killing it,” Goodson said.
He used a gardening analogy to explain how blue light – which is absorbed by porphyrins more readily than red or green light – can combat the growth of bacteria in the mouth. “You raise sunflowers in sun gardens, you raise toadstools in shade gardens. And the oral cavity is a garden that has seen very little light,” he said. “By introducing light into that environment, we would expect dramatic ecologic change.”
The discovery stemmed from Goodson’s observation while conducting unrelated research for BriteSmile (Walnut Creek, California), a provider of teeth whitening technology. In what he termed “a matter of serendipity,” he found that blue light used in the tooth whitening procedure appeared to decrease inflammation of the gums, which seemed to work by altering the underlying bacterial cause.
“Then we got very interested in sleuthing the question of which bacteria we might be affecting and if we could detect a change in bacteria that would be associated with it,” he said, explaining that the focus was narrowed to BPB. “We found that if we could pump large amounts of light into bacterial cultures that contained these bugs, they died within seconds. Then we began to think, ‘okay, this is a very interesting observation, now how would we move this technology into the mouth in a way that would benefit patients who would like to treat their gum disease?’”
This led to several studies, the most recent of which established “a killing effect in the laboratory, and also establish[ed] a mechanism by which the killing seems to be occurring,” Goodson said.
As for a timeline for development of the hand-held, light-based device, Goodson acknowledged that “a fair amount of money is needed to make it to the next step.” If funding is secured for further research – and that research is recognized by the scientific community – Goodson predicted a fairly fast time to market. “Depending how much enthusiasm went behind it, I think a product could be on the market within a year’s time of initiation.” He said the main task would be to establish efficacy. “And I think one or two really well-planned studies could show that in a reasonably short period of time.”
Goodson concluded: “The one thing that we have learned about the bacteria of the oral cavity is you’re never going to get rid of them.” Referring again to the gardening analogy, he advised: “What you want to do is weed it – get rid of the bad guys and leave the good guys.”