High Tech Mouthwash Uses Light To Kill Bacteria

According to the Health 2000 Population Survey over half of Finns aged 30+ suffer from gum disease; and research indicates that undetected oral and chronic infections can contribute to the occurrence of many diseases such as cardiovascular disease, diabetes, and lung cancer as well as increasing the risk of premature delivery. 

Aalto University and Helsinki University Hospital researchers have founded Koite Health which is launching a method for home use in the coming weeks that can kill streptococcus mutans bacteria as well as the bacteria that can cause gingivitis, which has been shown to reduce the markers indicating early gingivitis and plaque formation. 

"Dental diseases are caused by the combined effect of the bacterial community, and streptococcus mutans plays a key role in dental caries. For plaque, mutans is a bit like the first violin that starts a concert. It adheres to the tooth first and opens the door for other bacteria," says Researcher Tommi Pätilä, who is a cardiac surgeon at New Children's Hospital.

The process begins with using a mouthwash solution that contains a light absorbing compound which is rinsed around in the mouth for 30 seconds to let the photosensitive substance it contains stick to any plaque, then the substance is activated by a photosensitizer that is placed between the teeth. This dual light therapy treatment is to be administered to the entire dental area for 10 minutes, and based on studies it will only affect the targeted bacteria leaving the bacterial flora diverse without causing bacterial resistance. 

"The photosensitive substance in the effervescent tablet adheres to the surface structures of the bacteria. Red light activates the substance and initiates a chain-reaction that kills the bacteria. Antibacterial blue light administered at the same time significantly enhances the effect," explains Pätilä.

Light has been used in the past to kill bacteria, but bacteria living in the mouth is able to protect themselves from antibacterial blue light using various sugars to build a shelter. However, bacteria living in the mouth is not able to defend against the combination of the solution and dual light wavelength which affect the bacteria’s internal structures. Most dentists have already become familiar with light activate antibacterial methods, but dual light significantly boosts efficacy according to the researchers.

This technology was first tested on human subjects by treating canine teeth only on one side of the mouth once a day and leaving the other side as control; results showed significantly less plaque formation and other markers of gum disease on the side of the mouth using the treatment.  According to the researchers oral hygiene is still the best way to prevent dental disease, but dual light therapy is beneficial to those with aggressive strains of dental bacteria, chronic diseases, or to those with problems handing dental hygiene due to limitations. 

"Although dental care is generally better than earlier, the cost of oral diseases is around 442 billion dollars globally," says researcher Sakari Nikinmaa. "We especially hope that the product we've developed will help maintain the oral health of cancer patients who are undergoing intensive treatments and prevent gingivitis in diabetics. Diabetes causes a tenfold increase in the risk of gingivitis. The product is also suitable for daily tooth cleaning and maintenance of oral health.”