Evolution of the combined effect of different irrigation solutions and activation techniques on the removal of smear layer and dentin microhardness in oval-shaped root canal – An in-vitro study

Abstract

The aim of this in vitro study was to evaluate the effect of three final irrigants, namely QMix, MTAD and EDTA, combined with three irrigation techniques, namely conventional needle irrigation (CNI), passive ultrasonic irrigation (PUI) and photon-induced photoacoustic streaming (PIPS), on smear layer removal, dentin mineral content and microhardness in oval-shaped canals. 130 decoronated premolars with single, oval root canals were equally divided into1 blank control group and 12 treatment groups (n=10) according to the final irrigation protocols. Roots in treatment groups were instrumented with ProTaper Gold to size F4 and subjected to final irrigation. Smear layer removal was assessed by using a four-level scoring system under an environmental scanning electron microscope. Energy dispersive X-ray spectroscopy was performed to measure the dentin mineral content. Dentin microhardness was measured by Knoop microhardness testing. Statistical analysis of the data was performed by using Kruskal-Wallis test, followed by Dunn’s post hoc test with Bonferroni correction. PUI- and PIPS-activated QMix and EDTA removed smear layer more effectively than MTAD groups (p<0.05). Regarding the dentin mineral content and microhardness, QMix groups yielded the least calcium (Ca), phosphorus (P) and Ca/P ratio, followed by EDTA groups and MTAD groups (p<0.05). QMix groups produced significantly lower dentin microhardness values and higher hardness reduction percentages than MTAD groups (p<0.05). Within the limitations of the present study, it was concluded that QMix and EDTA were superior to MTAD in smear layer removal, especially when activated by PUI and PIPS, but these agents produced more pronounced effect on dentin mineral content and microhardness than MTAD.

Cleaning and Disinfecting Oval-Shaped Root Canals: Ex Vivo Evaluation of Three Rotary Instrumentation Systems with Passive Ultrasonic Irrigation

“…In this study, the ability of XPS, PTN, and HCM to remove the smear layer on the buccolingual canal walls of oval-shaped canals was enhanced when combined with antimicrobial irrigants and PUI, which agrees with the results reported in earlier studies [ 37 , 38 , 39 ]. Interestingly, although the same rotary system or irrigant was used, there was no significant difference observed in the removal of the smear layer across the entire length of the canals.…”

Micro-computed tomography (micro-CT) evaluation of root canal morphology in immature maxillary third molars

“…Bacteria and debris hidden in unprepared areas can be the source of persistent infection and lead to the failure of root canal therapy. Thus, the problem of cleaning and disinfecting root canals remains one of the most significant clinical challenges due to anatomical complexities [29]. A round configuration in the apical third predominates in all canals in the permanent maxillary molars with complete root development [30].…”

Effectiveness of Triton Irrigation Solution in Smear Layer Removal: An in-vitro Study

“…A high-speed diamond bur was used to create two parallel longitudinal grooves on the buccal and lingual portions of each root after the samples were removed from the mold ( 19 ). The opening was sealed with a tiny cotton plug; gutta-percha was inserted into the canal, which served as a gauge for the groove depth to prevent bur incursion into the canals, resulting in contamination from sectioning-related debris ( 20 ).…”