Effect of antimicrobial photodynamic therapy with red led and methylene blue on the reduction of halitosis: controlled microbiological clinical trial.

To determine the effect of antimicrobial photodynamic therapy (aPDT) using a red light-emitting diode (LED) on the reduction of halitosis and microbiological levels in the tongue coating immediately after irradiation, 7, 14, and 30 days after treatment. Forty-five young adults diagnosed with halitosis were allocated to three groups: G1, aPDT with 0.005% methylene blue and red LED (660 nm, four irradiation points, 90 s per point, power of 400 mW, 36 J per point, radiant exposure of 95 J/cm2, continuous wave); G2, tongue scraping; and G3, tongue scraping and aPDT. Gas chromatography was performed before and immediately after treatment, as well as at the different follow-up times. Microbiological samples were collected at the same times from the dorsum of the tongue, and bacteria were quantified in the samples using real-time PCRq. The Wilcoxon test was used for the intragroup analyses, and the Kruskal-Wallis test was used for the intergroup analyses. In the intragroup analyses, differences were found before and immediately after treatment in all groups (p < 0.05). The effect was maintained after 7 days only in the tongue scraping group (p < 0.05). In the intergroup analysis, no statistically significant differences were found among the groups (p > 0.05). For the microbiological analyses, no statistically significant differences were found in the groups/bacteria that were analyzed (p > 0.05). aPDT using a red LED and 0.005% methylene blue caused an immediate reduction in halitosis, but the effect was not maintained after 7, 14, or 30 days. No reduction occurred in the number of bacteria investigated or the quantification of universal 16S rRNA. ClinicalTrials.gov Identifier: NCT03656419.

Action of antimicrobial photodynamic therapy with red leds in microorganisms related to halitose: Controlled and randomized clinical trial.

INTRODUCTION: Halitosis is the term used to describe any unpleasant odor relative to expired air regardless of its source. The prevalence of halitosis in the population is approximately 30%, of which 80 to 90% of the cases originate in the oral cavity resulting from proteolytic degradation by gram negative anaerobic bacteria. Antimicrobial photodynamic therapy (aPDT) has been widely used with very satisfactory results in the health sciences. It involves the use of a non-toxic dye, called photosensitizer (FS), and a light source of a specific wavelength in the presence of the environmental oxygen. This interaction is capable of creating toxic species that generate cell death. The objective of this controlled clinical study is to verify the effect of aPDT in the treatment of halitosis by evaluating the formation of volatile sulphur compounds with gas chromatography and microbiological analysis before and after treatment. MATERIALS AND METHODS: Young adults in the age group between 18 and 25 years with diagnosis of halitosis will be included in this research. The selected subjects will be divided into 3 groups: G1: aPDT; G2: scraper, and G3: aPDT and scraper. All subjects will be submitted to microbiological analysis and evaluation with Oral ChromaTM before, immediately after treatment, 7, 14, and 30 days after treatment. For the evaluation of the association of the categorical variables the Chi-square test and Fisher's Exact Test will be used. To compare the means the student t test and analysis of variance (ANOVA) will be used and to analyse the correlation between the continuous variables the correlation test by Pearson will be applied. In the analyses of the experimental differences in each group the Wilcoxon test will be used. For all analyses a level of significance of 95% (P < .05) will be considered. DISCUSSION: Halitosis treatment is a topic that still needs attention. The results of this trial could support decision-making by clinicians regarding aPDT using aPDT for treating halitosis.