Effectiveness of irrigation strategies on the removal of the smear layer from root canal dentin

Abstract

The aim of this study was to evaluate the removal of the smear layer by some commonly used (needle-and-syringe irrigation, sonic activation, ultrasonically activated irrigation) and new root canal irrigation strategies (negative pressure irrigation and polymer rotary file) using a novel approach by comparing pre- and post-experimental images. Prepared root canals (n = 50) were subjected to a split tooth model and divided into 5 groups (n = 10): (1) needle-and-syringe irrigation (control); (2) sonic activation (SA); (3) negative pressure irrigation with continuous warm activated irrigation and evacuation (CWA); (4) polymer finishing file (FF); (5) ultrasonically activated irrigation (UAI). Smear layer scores and percentage of open dentinal tubules (%ODT) were evaluated by 2 examiners before and after irrigation procedures, from the middle and apical thirds of the root canal, on scanning electron microscopic images. Data were analysed using Kruskal-Wallis and post hoc tests at P = 0.05. Needle-and-syringe irrigation (control) showed no significant difference (both smear score and %ODT) compared to the pre-experimental value (P > 0.05). All other groups showed lower smear scores and higher %ODT, compared to the control (P < 0.05). The lowest smear score and highest %ODT were observed in the CWA group, which was significantly different from all other groups (P < 0.05). SA group showed significantly higher smear scores and lower %ODT than FF or UAI (P < 0.05). CWA showed superior removal of smear layer in the middle and apical thirds of the root canal compared to the other irrigation strategies.

Comparison of the efficacy of CanalBrush, EndoActivator, and Passive Ultrasonic Irrigation on the removal of triple antibiotic paste from root canal walls: An in vitro study

“…This result could be due to the fact that sonic frequency ranges are much lower than ultrasonic irrigation, and therefore the acoustic microstreaming would be lower, as would be the cleaning efficacy. [ 33 ] This study’s results were inconsistent with the above findings, may be because a different irrigation duration, and regime was applied.…”

Trends in Endodontic Protocols Amongst Dentists in Lahore

“…1,26 The aim to achieve 3-dimensional cleaning of the root canal space is not possible without irrigation solution reaching the apical one third of the working length followed by activation of irrigant with different activation methods as areas like isthmuses, apical deltas etc are not negotiable even with modern canal preparation methods. 25 In this survey 45.2% of the dentists were not using any irrigant activation method to increase the efficacy of irrigant whereas only 24.4 % used manual method of irrigant activation. With growing evidence, it has become evident that irrigant activation with ultrasonics, sonic activation, or negative pressure devices is very important for irrigant penetration in to the apical one third of the canal for achieving maximum disinfection of the canal.…”

“…24 Intracanal irrigation with 0.5-5.25% sodium hypochlorite is considered a gold standard antimicrobial agent to dissolve organic component of smear layer. 25 In this study the use of sodium hypochlorite primarily after access opening was practiced by 68.5% of the dentists. The results are consistent with the findings of studies done by Palmer et al in UK who reported 75% and Unal et al in Turkey showed 73% of the dentists practiced use of sodium hypochlorite primarily after access opening.…”

“…With growing evidence, it has become evident that irrigant activation with ultrasonics, sonic activation, or negative pressure devices is very important for irrigant penetration in to the apical one third of the canal for achieving maximum disinfection of the canal. 25,27 Direct irrigation of the canal with positive pressure irrigation needles is one of the most commonly used irrigation methods taught in undergraduate schools. For routine endodontic procedures a 27G needle placed 3 mm from the apex of a canal prepared is sufficient.…”

Comparison of Antibacterial Effect and Smear Layer Removal of Herbal versus Traditional Irrigants - An in vitro Study

“…The different methods of the root canal preparation result in formation of this coating; comprised of 2 areas: outer most organic layer which is about two microns, then subsequent area stretches out to dentinal tubules to a profundity of 40microns and is to a great extent made of dentin chips. (14). Moreover, achieving clean patent dentinal walls through eradication of this layer is necessary to enhance the smooth hermetic sealing of the entire configuration.…”