Department of Periodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan.
Photodiagnosis Photodyn Ther. 2020 Dec;32:102033. doi: 10.1016/j.pdpdt.2020.102033. Epub 2020 Oct 2.
This study aimed to investigate the effects of a new antimicrobial photodynamic therapy (aPDT) system using yellow-green light-emitting diode (YGL) and rose bengal (RB) on Porphyromonas gingivalis (Pg) in vitro.
Pg suspension mixed with RB was irradiated with YGL (565 nm) or blue light-emitting diode (BL, 470 nm) at 428 mW/cm in comparison with chlorhexidine (CHG) treatment. The cells were cultured anaerobically on agar plates, and the number of colony-forming units (CFU) was determined. The treated suspension was anaerobically incubated, and the cell density (OD) was monitored for 24 h. Also, the viability of treated human gingival fibroblast (HGF-1) was measured using WST-8 assay. Pg morphology was observed with a scanning electron microscope. The RNA integrity number of aPDT-treated Pg was determined and gene expressions were evaluated by quantitative real-time polymerase chain reaction.
RB + YGL (aPDT) demonstrated a significantly higher reduction of CFU, compared to RB + BL (aPDT) and CHG, furthermore the OD value rapidly decreased. Morphological changes of Pg with RB + YGL were more severe than with CHG. Although RB + YGL reduced HGF-1 viability, aPDT's impact was significantly lower than CHG's. With RB + YGL treatment, RIN values decreased; furthermore, gene expressions associated with DNA replication and cell division were remarkably decreased after 12 h.
The results of this study demonstrated that a novel aPDT system using RB + YGL may have potential as a new technical modality for bacterial elimination in periodontal therapy.
本研究旨在探讨使用黄绿光发光二极管（YGL）和玫瑰红 B（RB）的新型抗菌光动力疗法（aPDT）系统对体外牙龈卟啉单胞菌（Pg）的影响。
将 Pg 悬浮液与 RB 混合，用 YGL（565nm）或蓝光发光二极管（BL，470nm）照射，光强为 428mW/cm，与洗必泰（CHG）处理进行比较。细胞在琼脂平板上进行厌氧培养，并确定菌落形成单位（CFU）的数量。将处理过的悬浮液在厌氧条件下孵育，并监测 24 小时内的细胞密度（OD）。此外，使用 WST-8 测定法测定经处理的人牙龈成纤维细胞（HGF-1）的活力。用扫描电子显微镜观察 Pg 的形态。通过定量实时聚合酶链反应评估 aPDT 处理的 Pg 的 RNA 完整性数和基因表达。
与 RB+BL（aPDT）和 CHG 相比，RB+YGL（aPDT）显著降低 CFU，并且 OD 值迅速下降。用 RB+YGL 处理的 Pg 形态变化比 CHG 更严重。尽管 RB+YGL 降低了 HGF-1 的活力，但 aPDT 的影响明显低于 CHG。用 RB+YGL 处理后，RIN 值降低；此外，在 12 小时后，与 DNA 复制和细胞分裂相关的基因表达明显降低。
本研究结果表明，使用 RB+YGL 的新型 aPDT 系统可能具有作为牙周治疗中细菌消除新技术模式的潜力。
