A study has revealed that antimicrobial photodynamic therapy in which blue light targets annatto colorant is an effective option for treatment of halitosis in mouth-breathing children.

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

An article on the study is published in the journal PLOS ONE.

The study

The researchers selected 52 mouth-breathing children aged six to 12 with a diagnosis of halitosis, confirmed using a halimeter.

Antimicrobial photodynamic therapy (aPDT) consists of the administration of a photosensitiser combined with a light source at a specific wavelength, and oxygen. The procedure generates reactive oxygen species that induce bacterial cell death. Although the study only involved children, the method can treat halitosis in people of any age.

Sandra Kalil Bussadori, paediatric dentist and an author of the article, said, “The photosensitiser used in the study was annatto, which is reddish and was targeted by blue light from a light-emitting diode (LED) in the photopolymerising device most dentists now have in their consulting rooms, facilitating adoption of the protocol.”

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 children 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 1cm between points, a beam area of 2cm 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.

The results

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. However, the study did not find a direct correlation between tongue coating and halitosis in mouth-breathing children. Sandra said, “The main cause of bad breath in these children appears to be oral dryness due to mouth breathing.”

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

Author: