Efficacy of a novel remotely-generated ultrasonic root canal irrigation system for removing biofilm-mimicking hydrogel from a simulated isthmus model

Int Endod J. 2023 Jun;56(6):765-774. doi: 10.1111/iej.13905. Epub 2023 Mar 9.

Abstract

Aim: To evaluate the efficacy of a novel ultrasonic irrigation device, remotely-generated irrigation with a non-invasive sound field enhancement (RINSE) system, in removing biofilm-mimicking hydrogel from a simulated isthmus model and compare it with sonically- and ultrasonically-activated irrigation systems.

Methodology: A polycarbonate root canal model containing two standardized root canals (apical diameter of 0.20 mm, 4% taper, 18 mm long with a coronal reservoir) connected by three isthmuses (0.40 mm deep, 2 mm high, 4 mm long) was used as the test model. The isthmuses were filled with a hydroxyapatite powder-containing hydrogel. The canals were filled with irrigant, and the models were randomly assigned to the following activation groups (n = 15): EndoActivator (EA), ultrasonically activated irrigation (UAI), and RINSE system (RS). Syringe irrigation (SI) with a 30G needle served as the control. Standardized images of the isthmuses were taken before and after irrigation, and the amount of hydrogel removed was determined using image analysis software and compared across groups using anova (p < .05).

Results: Hydrogel removal was significantly higher with the RS (83.7%) than with UAI, EA, or SI (p ≤ .01). UAI (69.2%) removed significantly more hydrogel than SI and EA (p < .05), while there was no significant difference between SI (24.3%) and EA (25.7%) (p = .978).

Conclusions: RINSE system resulted in the most hydrogel removal, performing better than UAI or EA. The effect of RS was also not reliant on the insert or tip entering the pulp chamber or root canal, making it particularly useful in conservative endodontics.

Keywords: cavitation bubbles; gas bubbles; hydrogel biofilm model; irrigation technologies; minimally invasive approaches; vapor bubbles.

MeSH terms

  • Biofilms / radiation effects
  • Dental Pulp Cavity* / microbiology
  • Dental Pulp Cavity* / radiation effects
  • Hydrogels
  • Models, Anatomic
  • Root Canal Irrigants
  • Root Canal Preparation
  • Root Canal Therapy* / instrumentation
  • Root Canal Therapy* / methods
  • Sodium Hypochlorite
  • Therapeutic Irrigation / methods
  • Ultrasonic Waves*

Substances

  • Hydrogels
  • Root Canal Irrigants
  • Sodium Hypochlorite