Discipline of Prosthodontics, Operative Dentistry and Endodontics, Faculty of Dentistry, National University of Singapore, Republic of Singapore.
Ultrasound Med Biol. 2013 May;39(5):825-33. doi: 10.1016/j.ultrasmedbio.2012.12.006. Epub 2013 Feb 27.
In this study, the effect of high-intensity focused ultrasound (HIFU) on Enterococcus faecalis on both planktonic suspensions and biofilms was investigated. E. faecalis persist in secondary dental infections as biofilms. Glass-bottom Petri dishes with biofilms were centered at the focal point of the HIFU wave generated by a 250-kHz transducer. Specimens were subjected to HIFU exposure at different periods of 30, 60 and 120 s. The viable bacteria, removal effect and bacterial viability of biofilms attached to the Petri dish surface were studied by colony-forming units (CFUs), scanning electron microscopy and confocal microscopy, respectively. The removal and bactericidal effects of HIFU are dependent on the exposure time. A significant reduction in biofilm thickness and CFU was found with the increase in HIFU exposure. The removal or bactericidal effect of HIFU was more significant starting from 60 s of exposure. This study highlighted the potential application of HIFU as a novel method for root canal disinfection.
本研究旨在探讨高强度聚焦超声（HIFU）对浮游菌悬液和生物膜中粪肠球菌的影响。粪肠球菌作为生物膜存在于继发性牙感染中。将带有生物膜的玻璃底培养皿置于由 250kHz 换能器产生的 HIFU 波的焦点处。将标本暴露于 HIFU 下 30、60 和 120 s 的不同时间段。通过平板菌落计数法（CFU）、扫描电子显微镜和共聚焦显微镜分别研究了附着在培养皿表面的生物膜的活菌、去除效果和细菌活力。HIFU 的去除和杀菌效果取决于暴露时间。随着 HIFU 暴露时间的增加，生物膜厚度和 CFU 显著减少。HIFU 的去除或杀菌效果从 60 s 暴露开始更加显著。本研究强调了 HIFU 作为一种新型根管消毒方法的潜在应用。
