Micro‐CT evaluation of sonically and ultrasonically activated irrigation on the removal of hard‐tissue debris from isthmus‐containing mesial root canal systems of mandibular molars

Abstract

Aim To evaluate the efficacy of sonically and ultrasonically activated irrigation on removal of accumulated hard‐tissue debris (AHTD) in mesial root canal systems of mandibular molars using micro‐computed tomographic (micro‐CT) analysis. Methodology Forty mesial roots of mandibular molars with two independent canals joined apically by an isthmus (Vertucci type II) were selected. The root canals were instrumented using Reciproc R25 instruments, and specimens were scanned at a resolution of 10.5 μm. Subsequently, n = 10 roots were assigned to each of the four final irrigation groups such that the group means and variances were almost identical: sonically activated irrigation with EndoActivator (EA) or EDDY (ED), ultrasonically activated irrigation (UAI) and manual irrigation without activation (MI). The final irrigation procedures were performed using a total of 5 mL 1% NaOCl and 5 mL 15% EDTA per canal over 5 min with activation time of 4 × 20 s. Reconstructed data sets were coregistered, and the mean percentage reduction of AHTD after final irrigation was compared statistically between groups using analysis of variance at a significance level set at 5%. Results A significant reduction of AHTD was achieved after final irrigation in all groups (P < 0.05), ranging from 44.1% to 66.8%. The vol% of debris after irrigation was 3.7 ± 1.9% for EA, 3.3 ± 2.3% for ED, 2.1 ± 1.6% for UAI and 4.4 ± 2.3% for MI, with no significant difference between groups (P > 0.05). Conclusions None of the final irrigation protocols completely removed AHTD from mesial root canal systems in extracted human mandibular molars. Sonically and ultrasonically activated irrigation performed no better compared to manual irrigation.

Sonic irrigant activation for root canal disinfection: power modes matter!

“…Moreover, as in the majority of in vitro studies, single roots with a simple anatomy were used in the present investigation. Micro-computed tomography data suggest, however, that in the complex mesial root canal systems of mandibular molars sonic irrigant activation does not improve the removal of accumulated hard-tissue debris compared with conventional manual irrigation [10]. Whether or not the same holds true for the antimicrobial efficacy remains currently unclear.…”

“…EDDY (VDW GmbH, Munich, Germany), a flexible, non-cutting polyamide tip that is coupled to an air scaler handpiece, is used with sonic activation at a frequency of 5000 Hz to 6000 Hz [9]. Sonic activation with soft polymer tips promises to be an alternative irrigant activation technique without the risk of unintentional dentin removal, [10] and in vitro evidence suggests that the antimicrobial efficacy of sonic activation with EDDY is, at least, on par with ultrasonic irrigant activation in straight and curved root canals [11].…”

Micro‐CT study on the removal of accumulated hard‐tissue debris from the root canal system of mandibular molars when using a novel laser‐activated irrigation approach

“…AHTD has been assessed using a number of different methods including histology, scanning electron microscopy and sectioning methods (Haapasalo et al ). In recent years, micro‐CT has been used for evaluating the amount and distribution of AHTD in the canal isthmus (Paqué et al , Endal et al ) and the reduction in AHTD after various irrigation regimens (Freire et al , Keleş et al , Verstraeten et al , Rödig et al ). Micro‐CT is capable of imaging the root canal system three‐dimensionally and assessing inorganic debris quantitatively and qualitatively with high accuracy (Paqué et al , Robinson et al ).…”

Letter to the Editor

“…In that study, EDTA was used as the final irrigant in all groups, and it appears that it may have been the protagonist for the resultant removal of accumulated hard tissue debris from the root canals as per general knowledge available in the literature (Rödig et al . 2019, Zhao et al . 2019).…”