Notícia

Health Tech World (Reino Unido)

Fighting bad breath with light therapy (25 notícias)

Publicado em 26 de novembro de 2024

A new study shows that antimicrobial photodynamic therapy in which blue light targets annatto colorant is a feasible and effective option for treatment of bad breath in mouth-breathing children.

Mouth breathing dries up the saliva, reducing its antibacterial and cleansing effects, so that bas breath is likely to worsen as a result. Halitosis is the medical term for bad breath, which may reflect local or systemic conditions such as gingivitis, periodontal disease, diabetic acidosis, hepatic failure or respiratory infection.

For this study, the researchers selected 52 mouth-breathing children aged six to 12 years old with a diagnosis of halitosis, confirmed using an inexpensive halimeter available from online retailers.

The team used antimicrobial photodynamic therapy (aPDT), which consists of the administration of a photosensitiser, called annatto, combined with a light source at a specific wavelength, and oxygen. Annatto is an orange-reddish pigment derived from the seeds of Bixa orellana (achiote or urucum), a shrub native to tropical parts of the Americas.

The aPDT procedure generates reactive oxygen species that induce bacterial cell death.

“The photosensitiser used in the study was annatto, which is reddish and was targeted by blue light from a LED [ light-emitting diode ] in the photopolymerising device most dentists now have in their consulting rooms, facilitating adoption of the protocol,” said last author Sandra Kalil Bussadori, professor at UNINOVE.

According to Bussadori, any reference to photodynamic therapy in an academic context brings to mind the usual method that involves methylene blue photosensitiser and red laser light.

“But why not offer health professionals a more affordable option? It was this insight that led me to develop a photosensitiser for use with the LED photopolymerisation device dentists already have. For devices fitted with a blue LED, we would need to develop a red colorant. That’s why I thought of annatto,” she said.

After several formulations, in vitro experiments and clinical trials, Bussadori succeeded in perfecting an annatto spray, which she patented in 2020. Annatto pods and seeds are dark red when ripe.

The 52 children that met the criteria for inclusion in the study were given instructions on toothbrushing with fluoridated toothpaste and dental flossing three times per day after meals for 30 days.

They were randomly divided into two groups. One was given aPDT applied to the middle third of the dorsal surface of the tongue. The other used a tongue scraper and did not receive aPDT. Both groups used toothbrushing and flossing as noted.

In the single session of aPDT performed, the annatto photosensitiser was sprayed on to the tongue at a concentration of 20 per cent in a sufficient quantity to coat the middle third of the dorsum (five sprays) and left for two minutes to incubate.

Six points were irradiated with a distance of 1 cm between points, a beam area of 2 cm per point, and exposure of 20 seconds per point. Halitosis and tongue coating results before and after treatment, and seven and 30 days later, were analysed and compared.

Whitish or yellowish tongue coating is made up mainly of bacteria, metabolites and food debris that usually accumulate on the posterior portion of the tongue dorsum.

Several studies have demonstrated that there is a correlation between tongue coating and excessive concentrations of volatile sulphur compounds produced by bacteria, leading to bad breath, but the study did not find a direct correlation between tongue coating and halitosis in mouth-breathing children.

“The main cause of bad breath in these children appears to be oral dryness due to mouth breathing,” she said.

Halitosis improved significantly in both groups, but more so in the group that received aPDT.

The authors note that, although the study only involved children, the method can treat halitosis in people of any age.