Efficacy of photodynamic therapy and periodontal treatment in patients with gingivitis and fixed orthodontic appliances: Protocol of randomized, controlled, double-blind study.

It is known that the presence of orthodontic brackets predisposes for a change in the biofilm, facilitating the development of gingivits. The sites are difficult to access with a toothbrush and periodontal curette, worsening inflammation, in addition, a gingival hyperplasia is associated with poor hygiene. The objective of this study is to evaluate the impact of photodinamyc therapy (PDT) as an adjuvant treatment, considering clinical immunoregulatory and microbiological parameters. This randomized, controlled, double-blind clinical study will include 34 patients, both genders, having used fixed appliance for more than 12 months, with gingivitis. Participants will be divided into two groups: G1 (n = 17)- Scaling and Root Planing + PDT placebo and G2 (n = 17)- Scaling and Root Planing + PDT. In G2 the following dosimetric parameters will be used: methylene blue 0.005%, λ= 660 nanometers (nm), 9 Joules (J) per site, irradiance= 3.5Watts (W)/ centimeters (cm), radiant exposure= 318J/cm. All participants will receive oral hygiene guidance prior the curetes scaling. The clinical periodontal data to be analyzed are plaque index, gingival index and probing depth. Crevicular fluid, from 4 pre-determined sites and saliva, will be collected and analysed for IL-6, IL-1β, IL-8, TNF-α and IL-10 cytokines using ELISA (Enzyme immunoabsorption assay) method. Total Bacteria count will also be performed, by qPCR and Universal16SrRNA gene. All analysis will be realized using in the baseline (T0), 7 (T1) and 21 (T2) days after treatment. Oral health-related quality of life will be assessed using the OHIP-14 questionnaire at times T0 and T2. If sample distribution is normal, the Student T-test will be applied if it is not normal, the Mann-Whitney test will be used. The data will be presented in terms of ± PD and The significance level will be set at p < 0.05. Our results may improve quality of life and add data to establish a therapeutic alternative for gingivitis during the orthodontic treatment. Registration: clinicaltrials.gov NCT04037709. https://clinicaltrials.gov/ct2/show/NCT04037709 - Registered in July 2019.