Oral Medicine Department, Islamic Azad University, Dental Branch, Tehran, Iran.
Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Photodiagnosis Photodyn Ther. 2018 Mar;21:357-362. doi: 10.1016/j.pdpdt.2018.01.014. Epub 2018 Jan 31.
Lactobacillus is a cariogenic microorganism. Different therapeutic approaches including photodynamic therapy (PDT) have been suggested for treatment of bacterial infection. The purpose of the current study was to compare the effects of PDT with Indocyanine green (ICG) and Methylene blue (MB) photosensitizers (PSs) on Lactobacillus acidophilus (L. acidophilus).
In this in-vitro experimental study, 84 samples of L. acidophilus (1 McFarland standard) were compared in 14 experimental groups including: MB, ICG, 660-nm laser, 808-nm laser (pulsed, 74s/continuous-wave, 37s), different combinations of lasers and PSs, Chlorhexidine (CHX) 0.2%, sodium hypochlorite (NaOCl) 2.5%, penicillin 6.3.3 and control groups. The samples were cultured in microplates containing blood agar culture medium. After incubation at 37 °C for 48 h, the colony forming units (CFUs) of L. acidophilus were counted and compared before and after therapeutic interventions. Data were analyzed using SPSS19 software program according to one-way ANOVA test.
This study showed that the separate use of ICG, 660- and 808-nm lasers (pulsed, 74s/continuous-wave, 37s), and the combined use of 808-nm laser (pulsed, 74s/continuous-wave, 37s) and ICG have no significant inhibitory effect on L. acidophilus colonies (P > 0.05), whereas the separate use of MB and the combined use of 660-nm laser (continuous-wave, 37s/pulsed, 74s) and MB significantly inhibited the growth of L. acidophilus in comparison with the control group (p < 0.05). Likewise, CHX 0.2%, NaOCl 2.5% and penicillin 6.3.3 significantly inhibited the bacterial growth (p < 0.05).
The results showed that separate use of MB and combined use of 660-nm laser and MB have a significant inhibitory effect on L. acidophilus growth.
乳酸杆菌是一种致龋微生物。已经提出了包括光动力疗法（PDT）在内的不同治疗方法来治疗细菌感染。本研究的目的是比较 PDT 与吲哚菁绿（ICG）和亚甲蓝（MB）光敏剂（PS）对嗜酸乳杆菌（L. acidophilus）的影响。
在这项体外实验研究中，将 84 个嗜酸乳杆菌（1 McFarland 标准）样本比较了 14 个实验组，包括：MB、ICG、660nm 激光、808nm 激光（脉冲，74s/连续波，37s）、激光和 PS 的不同组合、洗必泰（CHX）0.2%、次氯酸钠（NaOCl）2.5%、青霉素 6.3.3 和对照组。将样本培养在含有血琼脂培养基的微孔板中。在 37°C 孵育 48 小时后，比较治疗干预前后嗜酸乳杆菌的菌落形成单位（CFU）。数据使用 SPSS19 软件程序根据单向方差分析进行分析。
本研究表明，ICG、660nm 和 808nm 激光（脉冲，74s/连续波，37s）的单独使用，以及 808nm 激光（脉冲，74s/连续波，37s）和 ICG 的联合使用对嗜酸乳杆菌菌落没有明显的抑制作用（P>0.05），而 MB 的单独使用以及 660nm 激光（连续波，37s/脉冲，74s）和 MB 的联合使用与对照组相比，显著抑制了嗜酸乳杆菌的生长（P<0.05）。同样，CHX 0.2%、NaOCl 2.5%和青霉素 6.3.3 也显著抑制了细菌的生长（P<0.05）。
结果表明，MB 的单独使用和 660nm 激光与 MB 的联合使用对嗜酸乳杆菌的生长有明显的抑制作用。
