Mini “light sabres” might one day replace the toothbrush in the ongoing battle against gum disease and tooth decay, as scientists are working on a new hand-held device that kills only the “bad” bacteria.
The researchers, from the Forsyth Institute in Boston, US, say that just 2 minutes of oral illumination with the new device every day should be enough to prevent, control or treat gum disease. The blue light emitted will be more effective at eradicating harmful bacteria than antiseptic mouthwash, they say.
‘”The patient feels nothing when blue light is applied to the dental pocket -, the area between the teeth and the gums where dental plaque resides,’” says researcher Nikos Soukos. “We think it will be particularly beneficial to those who don’t like using a toothbrush.”
Soukos’s team reports that the light kills the bacteria associated with gum disease but leaves “good” bacteria intact.
“Micro-organisms called black-pigmented bacteria (BPB) such as Porphyromonas gingivalis and Prevotella intermedia have been implicated in the initiation and progression of gum disease,” says Soukos. Blue light kills these bacteria because it is absorbed by specific chemical compounds within the bacteria – called iron-porphyrins – causing a cascade of reactions fatal to the organism.
Killed in seconds
In the experiments, blue light from a halogen lamp was shone onto pure cultures of BPB and onto plaque samples obtained from patients with chronic gum disease.
Bacteria in the pure culture were killed in seconds, whereas bacteria in the plaque samples were killed selectively. Those containing iron-porphyrins were most affected – a beneficial result as it is iron-porphyrins that help bacteria in harming the gums. It is the acidic environment produced by the harmful bugs that results in tooth decay.
The research stemmed from an observation by Forsyth researchers that the blue light used in tooth-whitening procedures also happened to reduce gum inflammation.
No apparent damage
In additional, as yet unpublished, research, Soukos’s group exposed micro-organisms and human cells in culture to the blue light and found that the bacteria could be eradicated with no apparent damage to the human cells.
Soukos believes the device will ultimately be more effective than mouthwash, since mouthwash cannot fully penetrate dental plaque and eliminate pathogenic species. He adds that bacteria can also become resistant to antiseptics in the mouthwash.
Denise McCarthy, a dental scientist at Trinity College Dublin in Ireland, says the approach is both novel and interesting. But she says it is too early to make a firm assessment of its usefulness: “I do not think people should be encouraged to abandon their toothbrushes just yet.”
Journal reference: Journal of Antimicrobial Agents and Chemotherapy (DOI: 10.1128/AAC.49.4.1391-1396.2005)
