Effect of final irrigation protocols on microhardness reduction and erosion of root canal dentin

Abstract

This study aimed to evaluate the effect of final irrigation protocols on microhardness reduction and erosion of root canal dentin. Sixty root canals from mandibular incisors were instrumented and randomly divided into six groups (n = 10) according to the irrigant used: QMiX, 17% EDTA, 10% citric acid (CA), 1% peracetic acid (PA), 2.5% NaOCl (solution control), and distilled water (negative control). The chelating solutions were used to irrigate the canal followed by 2.5% NaOCl as a final flush. After the irrigation protocols, all specimens were rinsed with 10 mL of distilled water to remove any residue of the chemical solutions. Before and after the final irrigation protocols, dentin microhardness was measured with a Knoop indenter. Three indentations were made at 100 µm and 500 µm from the root canal lumen. Afterwards, the specimens were prepared for scanning electron microscopic analysis and the amount of dentin erosion was examined. Wilcoxon and Kruskal-Wallis tests were used to analyze the results with a significance level set at 5%. At 100 µm, all protocols significantly reduced dentin microhardness (p < .05), while at 500 µm, this effect was detected only in the EDTA and QMiX groups (p < .05). CA was the irrigant that caused more extensive erosion in dentinal tubules, followed by PA and EDTA. QMiX opened dentinal tubules, but did not cause dentin erosion. Results suggest that QMiX and 17% EDTA reduced dentin microhardness at a greater depth. Additionally, QMiX did not cause dentin erosion.

Peracetic acid as a single endodontic irrigant: effects on microhardness, roughness and erosion of root canal dentin

“…Erosion caused by the PAA group was similar to that of the NaOCl and SS groups. This observation is not in line with that of the Baldasso et al (Baldasso et al, 2017) study, which showed higher erosion for the PAA (also 1%). This difference may be attributed to their use of PAA as a final irrigant, whereas we used PAA as a single irrigant, complemented with the action of endodontic files.…”

“…High erosion can alter the calcium and phosphorus content to a depth of 300 μm (Wang et al, ), thus compromising the root canal dentin structure, and increasing fracture risk (Baldasso et al, ; Qian et al, ). The present study revealed that the NaOCl‐EDTA‐NaOCl group promoted higher dentin erosion than the other groups, in cervical and middle root canal thirds.…”

“…As for smear layer removal, 0.5, 1, 2, and 2.25% PAA had efficacy similar to 17% EDTA (De-Deus et al, 2011;Lottanti et al, 2009). When used as final irrigant, 1% PAA did not change microhardness, and, unlike EDTA, removed the smear layer with no alteration in the inorganic structure of the dentin (Baldasso, Roleto, Silva, Morgental, & Kopper, 2017).…”

“…As for smear layer removal, 0.5, 1, 2, and 2.25% PAA had efficacy similar to 17% EDTA (De‐Deus et al, ; Lottanti et al, ). When used as final irrigant, 1% PAA did not change microhardness, and, unlike EDTA, removed the smear layer with no alteration in the inorganic structure of the dentin (Baldasso, Roleto, Silva, Morgental, & Kopper, ). Regarding the effect of 1% PAA on AH Plus bonding strength to dentin, there was no difference among 17% EDTA, 2.25% PAA, and 10% citric acid (Carvalho et al, ).…”

Assessment of Root Canal Smear Layer Removal Efficacy of Ethylenediaminetetraacetic acid, Etidronic Acid, and Chlorhexidine using Scanning Electron Microscope

“…However, demineralization might have a negative influence on the chemical and structural composition of dentin. 2 During root canal treatment, for removal of the smear layer, many materials have been used (ultrasonic instruments, lasers, and chelating agents) for chemical and mechanical debridement. Among chelating agents, EDTA is the most commonly used chelator in endodontics.…”