2026 Volume 35 Issue 3 Pages 155-164
Root canal irrigation is an important procedure in root canal treatment. Nano-bubbles have attracted considerable attention across various fields because of their cleaning and disinfecting properties, and Hyperdense-Nanobubble Ozone Water (Hd-NBOW) was recently developed. Hd-NBOW improves sterilization efficacy, and the presence of nano-bubbles may also enhance the cleaning effect. This study assessed the efficacy of Hd-NBOW as a root canal irrigant. Various root canal irrigants were used to irrigate the root canal of a smear layer model for 1 minute, after which the number of opening dentinal tubules was quantified. Next, various root canal irrigants were applied to a biofilm model for one minute, after which the metabolic activity of the biofilm was measured. Additionally, various root canal irrigants were applied to an infected root canal model for 1 minute, bacteria were cultured before and after irrigation, and the numbers of colony forming units (CFU) were determined. The same procedure was repeated 2 days later, and the treatment was performed a total of 3 times. The number of opening dentinal tubules in the smear layer model irrigated with Hd-NBOW was comparable to that in the model irrigated with 3% ethylenediaminetetraacetic acid solution. The biofilm model demonstrated a reduction in metabolic activity with Hd-NBOW irrigation, comparable to that with sodium hypochlorite solution. A reduction in CFU levels was observed immediately after cleaning with Hd-NBOW. Two days later, the CFU count still showed a decline. Hd-NBOW can be used for root canal irrigation because it has both smear layer removal and bactericidal effects on infected root canals.
