Department of Biosciences and Oral Diagnosis, School of Dentistry of São José dos Campos, Univ Estadual Paulista (UNESP), Francisco José Longo 777, São Dimas, São José dos Campos, 12245-000, SP, Brazil.
Lasers Med Sci. 2013 May;28(3):859-64. doi: 10.1007/s10103-012-1175-3. Epub 2012 Jul 31.
The purpose of this study was to evaluate specific effects of photodynamic inactivation (PDI) using erythrosine (ER) and Rose Bengal (RB) photosensitizers and a blue light-emitting diode (LED) on the viability of Streptococcus mutans and Streptococcus sanguinis biofilms. Biofilms were grown in acrylic disks immersed in broth to production of biofilms, inoculated with microbial suspension (10(6) cells/mL) and incubated for 48 h. After the formation of biofilms, the effects of the photosensitizers ER and RB at a concentration of 5 μM for 5 min and blue LED (455 ± 20 nm) for 180 s, photosensitizers alone and conjugated were evaluated. Next, the disks were placed in tubes with sterile physiological solution (0.9 % sodium chloride) and sonicated for to disperse the biofilms. Tenfold serial dilutions were carried and aliquots seeded in brain heart infusion agar which were then incubated for 48 h. Then the numbers colony-forming units per milliliter (CFU/mL; log10) were counted and analyzed statistically (ANOVA, Tukey test, P ≤ 0.05). Significant decreases in the viability of all microorganisms were observed for biofilms exposed to PDI mediated by both photosensitizers. The reductions with RB and ER were, 0.62 and 0.52 log10 CFU mL(-1) for S. mutans biofilms (p=0.001), and 0.95 and 0.88 log10 CFU mL(-1) for S. sanguinis biofilms (p=0.001), respectively. The results showed that biofilms formed in vitro by S. mutans and S. sanguinis, were sensitive to PDI using a blue LED associated with photosensitizers ER or RB, indicating its use in the control of caries and periodontal diseases.
本研究旨在评估血卟啉单甲醚（erbium）和孟加拉玫瑰红（Rose Bengal）光敏剂与蓝色发光二极管（LED）联合光动力灭活（PDI）对变形链球菌和中间普氏菌生物膜活力的特定影响。将生物膜在含有肉汤的丙烯酸盘内浸泡以形成生物膜，用微生物悬浮液（10(6) 个细胞/mL）接种，并孵育 48 h。生物膜形成后，评估浓度为 5 μM 的光敏剂 ER 和 RB 作用 5 min 以及蓝色 LED（455 ± 20 nm）作用 180 s 的效果，单独和联合使用光敏剂的效果。然后，将盘放入装有无菌生理盐水（0.9%氯化钠）的管中并进行超声处理以分散生物膜。进行十倍系列稀释，并将等分试样接种于脑心浸液琼脂中，然后孵育 48 h。然后对每毫升的菌落形成单位数（CFU/mL；log10）进行计数并进行统计学分析（方差分析、Tukey 检验，P ≤ 0.05）。与单独使用光敏剂相比，所有微生物的生物膜活力均显著降低。对于变形链球菌生物膜，RB 和 ER 的减少量分别为 0.62 和 0.52 log10 CFU mL(-1)（p=0.001），对于中间普氏菌生物膜，分别为 0.95 和 0.88 log10 CFU mL(-1)（p=0.001）。结果表明，体外形成的变形链球菌和中间普氏菌生物膜对蓝色 LED 联合 ER 或 RB 光敏剂的 PDI 敏感，表明其可用于控制龋齿和牙周疾病。
