A study by researchers working in Brazil shows that antimicrobial photodynamic therapy in which blue light targets annatto colorant is a feasible and effective option for treatment of halitosis in mouth-breathing children.
Annatto is an orange-reddish pigment derived from the seeds ofBixa orellana(achiote or urucum), a shrub native to tropical parts of the Americas.
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.
In their study—published inPLOS ONE—the team selected 52 mouth-breathing children aged 6–12 with a diagnosis of halitosis.
Antimicrobialphotodynamic therapy(aPDT) consists of the administration of a photosensitizer combined with a light source at a specific wavelength, and oxygen. The procedure generates reactive oxygen species that induce bacterial cell death.
“The photosensitiser used in the study was annatto, which is reddish and was targeted byblue lightfrom a LED in the photopolymerising device most dentists now have in their consulting rooms, facilitating adoption of the protocol,” said Professor Sandra Kalil Bussadori at Nove de Julho University in São Paulo.
According to Professor Bussadori, any reference to photodynamic therapy in an academic context brings to mind as first option 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.
Annatto pods and seeds are dark red when ripe.
The 52 children that met the criteria for inclusion in the study 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.
Halitosis and tongue coating results before and after treatment, and seven and 30 days later, were analysed and compared.
Halitosis improved significantly in both groups, but more so in the group that received aPDT.