Dentistry Department, State University of Maringá, Avenida Colombo, 5790 - Jardim Universitário, Maringá, CEP 87020-900 Paraná, Brazil.
Department of Physiological Sciences, School of Dentistry of Piracicaba, University of Campinas, Avenida Limeira, 901 - Bairro Areião, CEP 13414-903 Piracicaba, SP, Brazil.
Photodiagnosis Photodyn Ther. 2018 Sep;23:94-98. doi: 10.1016/j.pdpdt.2018.05.004. Epub 2018 May 12.
Photodynamic therapy (PDT) has demonstrated promising results in the treatment of several clinical pathologies through the photochemical reaction caused by the combination of a photosensitizer and a light source. The objective of this study was to evaluate the antimicrobial effect of the combination of the photosensitizers (PSs) erythrosine/methylene blue activated by a white halogen light device on Streptococcus mutans biofilm.
Two separate experiments were conducted, the first using the PSs at the concentration of 100 μM, and the second 250 μM. The PSs were tested on S. mutans biofilms cultured for 24 h in isolation, in combination, with and without light activation for 2 min fractionated in 4 periods of 30 s. After treatment, biofilms were diluted and plated on BHI medium and incubated for 24 h for colony forming units (CFU) counting. The results (log) were analyzed with ANOVA followed by Tukey test (p < 0.05).
The erythrosine/methylene blue combination activated by white halogen light at 100 and 250 μM, and erythrosine at 250 μM, methylene blue at 250 μM presented significantly reduced cell counts (3.2 log, 5.3 log, 4.5 log, 4.3 log, respectively) when compared to controls (p < 0.05).
PDT with the combination of erythrosine/methylene blue demonstrated better results that the PSs in isolation regardless of the concentration. The use of this combination at the concentration of 250 μM shows promise as an antibacterial treatment for carious lesions and should be further assessed.
光动力疗法 (PDT) 通过光敏剂与光源结合引起的光化学反应，在治疗多种临床病理方面显示出良好的效果。本研究旨在评估红色素/亚甲蓝组合在白色卤素光设备激活下对变形链球菌生物膜的抗菌效果。
进行了两项单独的实验，第一项实验使用浓度为 100μM 的 PS，第二项实验使用浓度为 250μM 的 PS。PS 用于在 24 小时内单独培养的 S. mutans 生物膜，以及在不进行光激活的情况下和分 4 个 30 秒周期进行光激活的情况下培养的生物膜。治疗后，将生物膜稀释并接种在 BHI 培养基上，孵育 24 小时以计算菌落形成单位 (CFU)。使用 ANOVA 分析结果（log），然后使用 Tukey 检验（p<0.05）。
红色素/亚甲蓝组合在 100 和 250μM 时，以及 250μM 的红色素和 250μM 的亚甲蓝在白色卤素光激活下，与对照组相比，细胞计数显著减少（分别为 3.2 log、5.3 log、4.5 log、4.3 log）（p<0.05）。
与单独使用 PS 相比，红色素/亚甲蓝的 PDT 无论浓度如何，都能取得更好的效果。该组合在 250μM 浓度下作为龋齿病变的抗菌治疗方法具有潜力，应进一步评估。
