Department of Restorative Dentistry - Dental Materials Division, Piracicaba Dental School - State University of Campinas, Av. Limeira, 901, Zip Code: 13414-903, Piracicaba, SP, Brazil.
Department of Restorative Dentistry - Operative Dentistry Division, Piracicaba Dental School - State University of Campinas, Av. Limeira, 901, Piracicaba, SP, Brazil; Department of Restorative Dentistry - Faculty of Dentistry, University of Costa Rica.Instalaciones Deportivas, 11501-2060, Montes de Oca, San José, Costa Rica.
Dent Mater. 2021 Jan;37(1):e1-e14. doi: 10.1016/j.dental.2020.09.015. Epub 2020 Nov 2.
This study aimed to test the efficacy of photodynamic inactivation (PDI) mediated by curcumin with EDTA against Streptococcus mutans in planktonic suspension using blue LED light.
Antibacterial activity of curcumin and EDTA was evaluated by determination of their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The fractional inhibitory concentration index (FICI) was used to estimate the synergistic effect of various combination ratios of curcumin and EDTA against S. mutans. Cultures of S. mutans (18 h, 37 °C, 5% C0) were prepared to test the effect of curcumin-mediated PDI (50 μM and 500 μM) with or without 0.4% EDTA and 40 s of light-activation with blue light. EDTA and each concentration of curcumin were also tested individually. Chlorhexidine (0.2%), was used as positive control. Planktonic suspensions were also analyzed by viable colony counts (VCC), confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and polymerase chain reaction (PCR).
The MIC values of curcumin and EDTA were 5 mM and 0.125% respectively. FICI showed a synergistic interaction between curcumin and EDTA. All the combinations with curcumin and blue LED light resulted in a complete inactivation of the S. mutans and CLSM confirms these results, TEM showed morphological changes produced by the PDI. No damage on DNA structure was detected by PCR.
Curcumin-mediated PDI with EDTA using a blue light, shows a strong inhibitory effect against S. mutans in planktonic culture. Because of the unspecific target mechanism, it could be a promising technique for disinfection of dental tissues.
本研究旨在通过使用蓝光激发 EDTA 增强的姜黄素介导光动力灭活（PDI）来检测其对浮游液中变异链球菌的疗效。
通过测定最小抑菌浓度（MIC）和最小杀菌浓度（MBC）评估姜黄素和 EDTA 的抗菌活性。采用部分抑菌浓度指数（FICI）来评估不同浓度姜黄素和 EDTA 组合对变异链球菌的协同作用。将变异链球菌（18 h，37°C，5%CO2）培养物制备成实验组，检测姜黄素介导 PDI（50 μM 和 500 μM）对不同浓度 EDTA（0.4%）和 40 s 蓝光照射的影响，同时还检测了 EDTA 和每种浓度姜黄素的单独作用，氯己定（0.2%）作为阳性对照。浮游液通过活菌计数（VCC）、共聚焦激光扫描显微镜（CLSM）、透射电子显微镜（TEM）和聚合酶链反应（PCR）进行分析。
姜黄素和 EDTA 的 MIC 值分别为 5 mM 和 0.125%。FICI 表明姜黄素和 EDTA 之间存在协同作用。所有与姜黄素和蓝光结合的组合都导致了变异链球菌的完全失活，CLSM 证实了这一结果，TEM 显示了 PDI 产生的形态变化。PCR 未检测到 DNA 结构的损伤。
使用蓝光激发 EDTA 增强的姜黄素介导 PDI 对浮游培养的变异链球菌具有强烈的抑制作用。由于其非特异性的靶标机制，它可能成为一种有前途的牙齿组织消毒技术。
