Methylene blue-mediated photodynamic therapy in the treatment of oral microbiota. A Systematic Review

Abstract

Objective: The objective of the present review was to relate the scientific production presented in the last 5 years on the effect of photodynamic therapy using the methylene blue photosensitizer on the microorganisms present in the oral biofilm. Methods: systematic review looking for research in English of primary studies such as randomized clinical trials and without randomization, individual case-control, and qualitative descriptive studies, using the PubMed/MEDLINE and Scopus databases as references, from 2017 to 2021. Results: 15 articles were analyzed, being 67% national publications and 33% international studies. Considering the samples described in the studies, 73% were in vitro, 7% were in vivo and 20% were clinical samples. As for the light source, 66% used laser, 20% used LED and 14% the association of laser and LED devices. The power density used ranged from 0.0026 W/cm2 to 1415 W/cm2. The energy density ranged from 3 J/cm2 to 640 J/cm2. The power ranged from 10 mW to 110 mW. The irradiation time ranged from 24 to 294 seconds. In most publications, 87% used the wavelength of 660 nm. As for the photosensitizer, the most used concentration, in 33% of the studies, was 0.01%, with the pre-irradiation time most used being 300 seconds in 40% of the studies. Conclusion: Photodynamic Methylene Blue Therapy is being accepted as effective in therapies of various oral curative conditions and has been shown to be a useful and effective therapy, as well as a complementary approach to control the development/growth of oral biofilm in clinical situations.

In vitro photodynamic inactivation of B. subtilis and E. coli O157 by a new chalcone conjugate photosensitizer tethered with the NMe 2 group as fluorescence donor auxochrome

“…Characterization details of the newly synthesized of the target triazoles OCH 2 ), 2.82 (s, 3H, C 2 −CH 3 ), 2.51 (s, 3H, C 6 -CH 3 ), 2.41 (s, 3H, Tol-CH 3 ) ppm; 13 The antimicrobial activity of the new triazoles was determined using a modi ed Kirby-Bauer disc diffusion method (Bauer, et al, 1966) [35]. Brie y, 100 µl of the test bacteria/fungi were grown in 10 ml of fresh media until they reached a count of approximately 10 8 cells/ml for bacteria or 10 5 cells/ml for fungi (Pfaller, et al, 1988).…”

“…ppm (CH 2 ), 2.6 ppm (H−C≡C) as well as the CH 3 at 2.4 ppm. In the13 C NMR spectrum, the characteristic signals of this group were observed at δ 76 ppm (C≡C), and 56 ppm (CH 2 ).Coupling of the azido and propargyl substrates under CuAAC conditions afforded the target 1,4disubstituted-1,2,3-triazoles 6a−e, and 8 in yields ranging from weak to nearly quantitative. The mass values agreed with the expected formulas.…”

“…The IR spectra hold the bathochromic shifted C = O str band at ύ ≈1658 cm −1 with the concurrent demise of the N 3 and the H−C≡C− stretching bands.1 H NMR spectra showed a sum of the substrate signals free of the alkyne proton signal. Both the 1 H NMR and the13 C NMR spectra displayed the key signals of the reactants. At least, the 2CH 3 groups of quinolone as well as the C = O of the chalcones.…”

“…NMe 2 ), 2.83 (s, 3H, C 2 −CH 3 ), 2.51 (s, 3H, C 6 −CH 3 ) ppm;13 C NMR (100 MHz, CDCl 3 ): δ C 188.83 (C = O), 161.27, 157.78, 151.91, 145.32, 144.50, 141.46, 138.85, 134.05, 132.64, 130.64, 130.37, 127.43, 124.85, 122.83, 121.47, 120.65, 117.37, 116.46, 114.50, 111.94 (23 C−Ar, CH = CHCO), 61.91 (OCH 2 ), 40.23 (NMe 2 ), 21.97 (CH 3 ) ppm; EI−MS (m/z, %) for C 31 H 29 N 5 O 2 (503.61): 503.45 (M + ), 477.10 (50.32), 458.59 (18.07), 442.02 (26.16), 406.15 (39.15), 375.00 (52.13), 333.75 (57.36), 294.85 (47.79), 255.35…”

“…), 5.49 (s, 2H, OCH 2 ), 3.86 (s, 3H, OCH 3 ), 2.82 (s, 3H, C 2 −CH 3 ), 2.51 (s, 3H, C 6 −CH 3 ) ppm;13 C NMR (100 MHz, CDCl 3 ): δ C 188.733 (C = O), 161.64, 161.61, 158.10, 147.70, 144.16, 144.12, 140.49, 138.05, 133.23, 132.07, 131.52, 131.36, 130.81, 130.18, 128.69, 127.68, 124.90, 121.09, 120.59, 119.33, 117.35, 114.62, 114.42, 113.61, 101.38 (23 C−Ar, CH = CHCO), 61.97 (OCH 2 ), (73.84), 238.30 (95.41), 195.16 (60.58), 182.23 (100). UV−vis (DMSO): λ max (nm); 269, 290, 421.…”