Smear Layer Removal Using Passive Ultrasonic Irrigation and Different Concentrations of Sodium Hypochlorite.

Abstract

INTRODUCTION:

The present study evaluated the effect of passive ultrasonic activation (PUI) of EDTA solution followed by conventional irrigation with 2 concentrations of sodium hypochlorite (NaOCl) on smear layer removal.

METHODS:

Fifty single-root mandibular premolars were chemomechanically prepared with ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) nickel-titanium rotary instruments and 1% NaOCl. The roots were cleaved, and the dentin surfaces were analyzed with scanning electron microscopy operated at a low vacuum. Images were obtained from previously demarcated areas in each root canal third. The teeth were reassembled and distributed into 5 groups according to the final irrigation protocols (n = 10): group 1, EDTA/PUI + 1% NaOCl; group 2, EDTA/PUI + 5% NaOCl; group 3, EDTA/CI + 1% NaOCl; group 4, EDTA/CI + 5% NaOCl; and group 5 (negative control), saline solution/PUI. After irrigation, the teeth were reseparated and prepared for conventional high-vacuum scanning electron microscopy of the same dentin surface that was previously analyzed. The amount of debris was classified using a 4-point scoring system. Data were analyzed with Kruskal-Wallis and Dunn tests at α = 0.05.

RESULTS:

Groups 1 and 2, which used PUI and different concentrations of NaOCl, were not significantly different; however, they differed significantly from group 3 (P < .05). With respect to canal cleanliness at different root thirds, all groups showed the worst cleaning at the apical third.

CONCLUSIONS:

PUI activation of the EDTA irrigant is required when canal debridement is performed with EDTA and a lower concentration of NaOCl.

• Authors: Nayra Bittencourt Orlowski, Tamer Ferreira Schimdt, Cleonice da Silveira Teixeira, Lucas da Fonseca Roberti Garcia, Julia Menezes Savaris, Franklin R Tay, Eduardo Antunes Bortoluzzi
• Journal: Journal of endodontics (J Endod) Vol. 46 Issue 11 Pg. 1738-1744 (Nov 2020) ISSN: 1878-3554 [Electronic] United States
• PMID: 32721483 (Publication Type: Journal Article)
• Copyright: Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Chemical References

• Root Canal Irrigants
• Edetic Acid
• Sodium Hypochlorite

Topics

• Bicuspid
• Dental Pulp Cavity
• Edetic Acid
• Humans
• Microscopy, Electron, Scanning
• Root Canal Irrigants
• Root Canal Preparation
• Smear Layer
• Sodium Hypochlorite
• Therapeutic Irrigation
• Ultrasonics