Development of a new root canal irrigation system using nanobubbles and its clinical application

本研究的目的是开发一种新型的纳米气泡根管冲洗系统，并将其应用于临床。建立了一种简单可靠的检测细菌数量的方法，该方法测量细菌的ATP活性，并将其转化为荧光素酶的活性。其次，确定了对组织无害的次氯酸钠浓度为0.5%。测定了纳米气泡与超声波联合作用的增强效果。将菌液放置在200ul的一次性管尖中，作为人工根管。在有或没有纳米气泡的情况下，用超声波将次氯酸钠(0.5%)应用到细菌溶液中。超声作用下的纳米气泡显著增强了低浓度次氯酸钠的杀菌效果。用透射电子显微镜评价了超声作用下纳米气泡对细菌的形态效应。单独使用超声波和纳米气泡对粪肠球菌表面形态无明显影响，但纳米气泡对粪肠球菌表面有明显的破坏作用。超声作用下纳米气泡对细菌细胞表面的破坏可能与低浓度次氯酸钠的杀菌效果增强有关。

The objectives of this study were development of a new root canal irrigation system using nanobubbles and its clinical application. A simple and reliable protocol to detect the number of bacteria measuring their ATP activity which was converted to luciferase activity was established. Next, concentration of sodium hypochlorite which is not harmful to tissues was determined to be 0.5%. Enhanced effects of nanobubbles conjunction with ultrasounds were determined. The bacterial solution was placed in the disposable pipet tips of 200ul which were used as artificial root canals. Sodium hypochlorite (0.5%) in the presence or absence of nanobubbles with ultrasounds was applied to the bacterial solution. Nanobubbles with ultrasounds significantly enhanced the bactericidal effects of low concentrated sodium hypochlorite. Morphological effects of nanobubbles with ultrasounds for bacteria were evaluated by transmission electron microscopy (TEM). There was no morphological change on the surface of Enterococcus faecalis (EF) by ultrasound or nanobubbles only, however the destruction of the surface of EF was induced by nanobubbles with ultrasound. Destruction of the cell surface of bacteria by nanobubbles with ultrasound may be involved in the enhancement of bactericidal effects of low concentrated sodium hypochlorite.