Schiffner Ulrich, Cachovan Georg, Bastian Jochen, Sculean Anton, Eick Sigrun
Center for Oral and Dental Medicine, Department of Restorative and Preventive Dentistry, University Center Hamburg-Eppendorf , Hamburg , Germany.
Acta Odontol Scand. 2014 Nov;72(8):673-80. doi: 10.3109/00016357.2014.898087. Epub 2014 Mar 21.
To investigate the lethal activity of photoactivated disinfection (PAD) on Enterococcus faecalis (ATCC 29212) and mixed populations of aerobic or anaerobic bacteria in infected root canals using a diode laser after the application of a photosensitizer (PS).
First, the bactericidal activity of a low power diode laser (200 mW) against E. faecalis ATCC 29212 pre-treated with a PS (toluidine blue) for 2 min were examined after different irradiation times (30 s, 60 s and 90 s). The bactericidal activity in the presence of human serum or human serum albumin (HSA) was also examined. Second, root canals were infected with E. faecalis or with mixed aerobic or anaerobic microbial populations for 3 days and then irrigated with 1.5% sodium hypochlorite and exposed to PAD for 60 s.
Photosensitization followed by laser irradiation for 60 s was sufficient to kill E. faecalis. Bacteria suspended in human serum (25% v/v) were totally eradicated after 30 s of irradiation. The addition of HSA (25 mg/ml or 50 mg/ml) to bacterial suspensions increased the antimicrobial efficacy of PAD after an irradiation time of 30 s, but no longer. The bactericidal effect of sodium hypochlorite was only enhanced by PAD during the early stages of treatment. PAD did not enhance the activity of sodium hypochlorite against a mixture of anaerobic bacteria.
The bactericidal activity of PAD appears to be enhanced by serum proteins in vitro, but is limited to bacteria present within the root canal.
研究在应用光敏剂（PS）后，使用二极管激光对粪肠球菌（ATCC 29212）以及感染根管中的需氧或厌氧细菌混合菌群进行光活化消毒（PAD）的致死活性。
首先，检测低功率二极管激光（200 mW）对用PS（甲苯胺蓝）预处理2分钟的粪肠球菌ATCC 29212在不同照射时间（30秒、60秒和90秒）后的杀菌活性。还检测了在人血清或人血清白蛋白（HSA）存在下的杀菌活性。其次，将根管感染粪肠球菌或需氧与厌氧微生物混合菌群3天，然后用1.5%次氯酸钠冲洗并暴露于PAD 60秒。
光敏化后激光照射60秒足以杀死粪肠球菌。照射30秒后，悬浮在人血清（25% v/v）中的细菌被完全根除。在细菌悬液中添加HSA（25 mg/ml或50 mg/ml）在照射30秒后提高了PAD的抗菌效果，但之后不再提高。次氯酸钠的杀菌作用仅在治疗早期被PAD增强。PAD并未增强次氯酸钠对厌氧细菌混合物的活性。
体外实验中，血清蛋白似乎增强了PAD的杀菌活性，但仅限于根管内存在的细菌。
