AIM To assess a novel, noninvasive intervention capable of mobilizing charged antibacterial nanoparticles to the apical portions of the root canal system, utilizing the principles of electrokinetics. METHODS Experiments were conducted in three stages. Stage-1: A computer model was generated to predict and visualize the electric field and current density distribution generated by the proposed intervention. Stage-2: Transport of chitosan nanoparticles (CSnp) was evaluated qualitatively using a transparent microfluidic model with fluorescent-labelled CSnp. Stage-3: An ex vivo model was utilized to study the antimicrobial efficacy of the proposed treatment against 3-week-old monospecies E. faecalis biofilms. Scanning electron microscopy (SEM) was also utilized in this stage to confirm the deposition of CSnp. RESULTS The results of the computer simulations predicted an electric field and current density that reach their maxima at the apical constriction of the root canal. Correspondingly, the microfluidic experiments demonstrated rapid, controlled CSnp transport throughout the simulated root canal anatomy with subsequent distribution and deposition in the apical constriction as well as periapical regions. Infected root canals when subjected to the novel treatment method resulted in a mean bacterial reduction of 2.1 log CFU. SEM analysis revealed electrophoretic deposition of chitosan nanoparticles onto the root canal dentine walls in the apical region. CONCLUSION The findings from this study demonstrate that the combination of cationic antibacterial nanoparticles with a low-intensity electric field results in particle transportation (electrophoresis) and deposition within the root canal. This results in a synergistic antibiofilm efficacy and has the potential to enhance root canal disinfection.

中文翻译：

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用于牙髓消毒的抗菌纳米颗粒的电动迁移和分布。

目的利用电动原理评估能够将带电的抗菌纳米颗粒动员至根管系统根尖的新型，非侵入性干预措施。方法实验分三个阶段进行。第一阶段：生成计算机模型，以预测和可视化所建议的干预措施所产生的电场和电流密度分布。第二阶段：使用带有荧光标记的CSnp的透明微流体模型定性评估壳聚糖纳米颗粒（CSnp）的运输。第三阶段：利用离体模型研究拟议治疗对三周大的单种粪肠球菌生物膜的抗微生物功效。在此阶段还使用扫描电子显微镜（SEM）来确认CSnp的沉积。结果计算机模拟的结果预测了在根管根尖处达到最大值的电场和电流密度。相应地，微流体实验表明，CSnp在整个模拟根管解剖结构中快速受控地运输，随后在根尖收缩区和根尖周围区域分布和沉积。受到新颖治疗方法感染的根管导致细菌平均减少2.1 log CFU。SEM分析表明，壳聚糖纳米粒子电泳沉积在根尖区的根管牙本质壁上。结论这项研究的结果表明，阳离子型抗菌纳米粒子与低强度电场的结合可导致根管内的粒子运输（电泳）和沉积。这导致协同的抗生物膜功效，并具有增强根管消毒的潜力。