An in vitro study of a novel quaternary ammonium silane endodontic irrigant.

Objective: To analyze effect of NaOCl+2% quaternary ammonium silane (QAS)-containing novel irrigant against bacteria impregnated inside the root canal system, and to evaluate its antimicrobial and mechanical potential of dentine substrate.
Methods: Root canal was prepared using stainless steel K-files™ and ProTaper™ and subjected to manual and ultrasonic irrigation using 6% NaOCl+2% CHX, 6% NaOCl+2% QAS and saline as control. For confocal-microscopy, Raman spectroscopy and SEM analysis before and after treatment, Enterococcus faecalis cultured for 7 days. Raman spectroscopy analysis was done across cut section of gutta percha/sealer-dentine to detect resin infiltration. Indentation of mechanical properties was evaluated using a Berkovich indenter. The contact angle of irrigants and surface free energy were evaluated. Mineralization nodules were detected through Alazarin red after 14 days.
Results: Control biofilms showed dense green colonies. Majority of E. faecalis bacteria were present in biofilm fluoresced red in NaOCl+2% QAS group. There was reduction of 484cm ^-1 Raman band and its intensity reached lowest with NaOCl+2% QAS. There was an increase in 1350-1420cm ^-1 intensity in the NaOCl+2% CHX groups. Gradual decrease in 1639cm ^-1 and 1609cm ^-1 Raman signal ratios were seen in the resin-depth region of 17μm>, 14.1μm> and 13.2μm for NaOCl+2% QAS, NaOCl+2% CHX and control groups respectively. All obturated groups showed an intact sealer/dentine interface with a few notable differences. 0.771 and 83.5% creep indentation distance for NaOCl+2% QAS ultrasonic groups were observed. Highest proportion of polar component was significantly found in the NaOCl+2% QAS groups which was significantly higher as compared to other groups. Mineralized nodules were increased in NaOCl+2% QAS.
Significance: Favorable antimicrobial and endodontic profile of the NaOCl+2% QAS solution might suggest clinical use for it for more predictable reduction of intracanal bacteria.
(Copyright © 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)