Decker Eva-Maria, Bartha Valentin, von Ohle Christiane
Department of Conservative Dentistry and Periodontology, Center of Dentistry, Oral Medicine, and Maxillofacial Surgery, University Hospital , Tübingen, Germany .
Photomed Laser Surg. 2017 Apr;35(4):195-205. doi: 10.1089/pho.2016.4152. Epub 2017 Jan 9.
Aim of the study was to improve the antibacterial efficacy of toluidine blue (TBO)/methylene blue (MB)-mediated photodynamic systems with light-emitting diode (LED) or laser irradiation administered to planktonic and biofilm-associated periodontopathogens.
Antibacterial photodynamic therapy (PDT) is a common, noninvasive adjunctive clinical method to inactivate microorganisms. So far, the disadvantage of this method has been its limited effectiveness in eliminating pathogens.
An anaerobic cocktail consisting of six representative periodontal pathogens was prepared as initial culture for planktonic samples and biofilms grown on human tooth slides. Both types of microbial samples were exposed to three commercial photodynamic systems (PDT1: TBO, 630 nm LED, PDT2: TBO, 635 nm laser, PDT3: MB, 665 nm laser) in conventional and a new modified approach (PDT) based on the use of an oxygen supplement (photosensitizer+hydrogen peroxide). The microbial viability was characterized by bacterial growth [colony forming units (CFU)], total bacterial cell counts, and microbial vitality. Statistical data analysis was performed using 95% confidence intervals (ANOVA) and post hoc Tukey's test (p < 0.05).
The modified PDT showed the highest statistically significant synergistic antimicrobial activity for TBO-based systems evidenced by a CFU reduction of 9 log units to 0 for planktonic pathogens and a 4 log CFU reduction for biofilm bacteria. The MB-based PDT was superior mainly against biofilm pathogens. By comparison, the default TBO-based PDT achieved colony growth reductions of 2 and 1 log units concerning planktonic and biofilm cells.
Compared to conventional PDT, PDT showed superior antibacterial efficacy based on its synergistic effect, promising vast application possibilities.
本研究的目的是通过发光二极管（LED）或激光照射，提高甲苯胺蓝（TBO）/亚甲蓝（MB）介导的光动力系统对浮游和生物膜相关牙周病原体的抗菌效果。
抗菌光动力疗法（PDT）是一种常见的、非侵入性的使微生物失活的辅助临床方法。到目前为止，该方法的缺点是其在消除病原体方面的有效性有限。
制备了一种由六种代表性牙周病原体组成的厌氧混合菌液，作为浮游样本和在人牙片上生长的生物膜的初始培养物。两种类型的微生物样本均暴露于三种商业光动力系统（PDT1：TBO，630nm LED；PDT2：TBO，635nm激光；PDT3：MB，665nm激光），采用传统方法和基于使用氧气补充剂（光敏剂+过氧化氢）的新改良方法（PDT）。通过细菌生长[菌落形成单位（CFU）]、细菌总数和微生物活力来表征微生物活力。使用95%置信区间（方差分析）和事后Tukey检验（p<0.05）进行统计数据分析。
改良后的PDT对基于TBO的系统显示出最高的统计学显著协同抗菌活性，浮游病原体的CFU减少9个对数单位至0，生物膜细菌的CFU减少4个对数单位。基于MB的PDT主要对生物膜病原体具有优势。相比之下，默认的基于TBO的PDT使浮游和生物膜细胞的菌落生长减少了2个和1个对数单位。
与传统PDT相比，PDT基于其协同效应显示出卓越的抗菌效果，具有广阔的应用前景。
