Evaluation of antimicrobial photodynamic therapy with acidic methylene blue for the treatment of experimental periodontitis

Abstract

Objective To investigate the security and effectiveness of antimicrobial photodynamic therapy (aPDT) with a citric acid-based methylene blue (MB) on the periodontal repair following the treatment of ligature-induced experimental periodontitis (EP) in rats. Material and methods Were used 120 male rats, randomly divided into 4 experimental groups (n = 30): no treatment (NT), SRP alone (SRP), SRP plus aPDT using conventional MB pH 7.0 (aPDT-pH7), SRP plus aPDT using acidic MB pH 1.0 (aPDT-pH1). EP was induced at day 0 by the placement of a ligature around the mandibular left first molars. Ten animals per group/period were euthanized at 14, 22 and 37 days. Histopathological, histometric (percentage of bone in the furcation [PBF]) and immunohistochemical (for tartrate-resistant acid phosphatase [TRAP] and osteocalcin [OCN]) analyses were performed. Data were statistically analyzed. Results aPDT-pH1 showed the highest PBF as compared with the other treatments. Collectively, tissues’ reaction to both dyes were controlled and healthy for the periodontium. Both aPDT protocols reduced the extent and intensity of the local inflammatory response, reduced the alveolar bone resorption, and promoted a better structural arrangement of the connective tissue as compared with SRP. TRAP expression was downregulated while OCN expression was upregulated by aPDT as compared with SRP alone. Conclusion Our data implicate that the novel MB pH 1.0 is as safe as the conventional MB for use in aPDT and raises its additional benefit of increasing the amount of alveolar bone in the furcation.

Benefits of Antimicrobial Photodynamic Therapy as an Adjunct to Non-Surgical Periodontal Treatment in Smokers with Periodontitis: A Systematic Review and Meta-Analysis

“…Regarding the photosensitizer used in the photodynamic therapy of the included RCTs, two studies [20,29] that used methylene blue associated with aPDT, with concentrations of 0.01% to 10mg/mL, showed better results compared to the phenothiazine chloridebased photosensitizer at 100 µg/mL. Some studies [37][38][39] suggest that photodynamic therapy associated with methylene blue may be effective in reducing the intensity of the local inflammatory response [38], promoting a better structural arrangement of the connective tissue [39], and reducing the depth of the periodontal pocket [37,38]. Two other studies [25,26] used chloro-aluminum phthalocyanine (CAP) at a concentration of 1.5 mg/mL and obtained statistically significant results in favor of the aPDT group for clinical and microbiological parameters compared to the SRP group.…”

“…All the patients participating in the studies were diagnosed with periodontitis, studies used the classification of generalized chronic periodontitis (CP) [20,21,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], a two studies [25,26] included a stage classification according to a 2017 workshop [31]. studies recruited patients with clinical attachment loss (CAL) ranging from ≥3m [24,25,29] to ≥5 mm [20,21,26] and two studies did not mention the CAL value [27,28], b did mention the probing depth (PD).…”