Comparative study of photodynamic therapy with LED and probiotics in the treatment of halitosis: protocol for a randomised controlled clinical trial.

Abstract

Halitosis is a term that defines any unpleasant odour smell originating from the oral cavity and may have a local or systemic origin. This project aims to determine the effectiveness of treatment involving antimicrobial photodynamic therapy (aPDT) combined with treatment using probiotics at reducing halitosis. 92 individuals from 18 to 60 years of age with a diagnosis of halitosis (sulfide≥112 ppb, gas chromatography) will be selected. The participants will be randomly allocated to four groups (n=23). Group 1 (control): brushing, dental floss and tongue scraper; group 2: brushing, dental floss, tongue scraper and aPDT with blue Light Emitting Diode (LED) +annatto; group 3: brushing, dental floss, tongue scraper and aPDT with blue Light Emitting Diode (LED) +annatto and probiotic lozenges containing <i>Streptococcus salivarius</i> K12 (BLIS K12); and group 4: brushing, dental floss, tongue scraper and probiotic lozenges containing <i>S. salivarius</i> K12 (BLIS K12). Comparisons will be made of the respiratory analysis results before and immediately after the first treatment session, at the end of the 30-day treatment period and again 60 days after the treatment initiation. Microbiological analysis (counts of colony-forming units of viable bacteria from coated tongue) will be performed at the same time. The microbiome analysis will be conducted before treatment, 30 days after treatment completion and 60 days after treatment initiation, following DNA extraction. All groups will receive oral hygiene instructions as well as brushes, toothpaste and dental floss. Data normality will be checked using Shapiro-Wilk test. In the case of normality, analysis of variance is used for the comparisons. In the case of non-parametric data, Kruskal-Wallis test will be used. Wilcoxon test will be used to analyse the results of each treatment between two assessment times. This protocol has been approved by the Human Research Ethics Committee of Nove de Julho University (certificate number: 82830524.6.0000.5511; approval date: 2 October 2024). Participants will agree to take part in the study by signing an informed consent form. The findings will be published in a peer-reviewed journal. The collected data will be available in the OSF data repository. NCT06583720.