Masuda Yoshiko, Sakagami Hiroshi, Horiike Masashi, Kadokura Hiroshi, Yamasaki Takahide, Klokkevold Perry R, Takei Henry H, Yokose Satoshi
Division of Endodontics and Operative Dentistry, Department of Restorative and Biomaterials Sciences, School of Dentistry, Meikai University, Saitama, Japan
Meikai University Research Institute of Odontology (M-RIO), Saitama, Japan.
In Vivo. 2018 Jul-Aug;32(4):707-712. doi: 10.21873/invivo.11298.
BACKGROUND/AIM: Enterococcus faecalis is responsible for most cases of endodontic treatment failure. Despite various conventional disinfection methods, root canals are not completely free of microorganisms. Photodynamic therapy (PDT) is a new antimicrobial strategy that involves the use of a non-toxic photosensitizer (PS) and a light source. The aim of this study was to evaluate the antimicrobial effect of PDT using diode laser and pyoktanin blue (PB) and confirm the nontoxicity of PB as a PS.
Laser irradiation with an output power of 3 W was performed with PB as the PS to a bacterial solution containing E. faecalis. Then, the number of colony-forming units was counted. PB cytotoxicity was also assessed by the MTT assay.
E. faecalis counts were reduced after laser irradiation, laser irradiation with PB, or the combination thereof compared to the control, non-irradiation or water. The 50% cytotoxic concentration value for adult human dermal fibroblasts incubated with PB for 1 min was 108 μg/ml.
Diode laser irradiation in combination with PB as the PS is efficacious for the elimination of E. faecalis without toxic effects to human dermal fibroblasts. This strategy might be useful for root canal irrigants.
背景/目的：粪肠球菌是导致大多数根管治疗失败的原因。尽管有各种传统消毒方法，但根管内仍不能完全清除微生物。光动力疗法（PDT）是一种新的抗菌策略，涉及使用无毒的光敏剂（PS）和光源。本研究的目的是评估使用二极管激光和碱性品红（PB）的光动力疗法的抗菌效果，并确认PB作为光敏剂的无毒性。
以PB作为光敏剂，对含有粪肠球菌的细菌溶液进行输出功率为3W的激光照射。然后，计算菌落形成单位的数量。还通过MTT法评估PB的细胞毒性。
与对照、未照射或水相比，激光照射、用PB进行激光照射或两者联合照射后，粪肠球菌数量减少。用PB孵育1分钟的成人人类皮肤成纤维细胞的50%细胞毒性浓度值为108μg/ml。
二极管激光照射联合PB作为光敏剂可有效消除粪肠球菌，且对人类皮肤成纤维细胞无毒性作用。该策略可能对根管冲洗剂有用。
