The Effect of Different Final Irrigation Regimens on the Dentinal Tubule Penetration of Three Different Root Canal Sealers: A Confocal Laser Scanning Microscopy Study In Vitro.

Tufan Ozasir,Mete Ungor,Kamran Gulsahi,Birgul Eren,Stefan G Stanciu

doi:10.1155/2021/8726388

Abstract

This study evaluated the effects of different final irrigation regimens on the dentin tubule penetration of three different root canal sealers using confocal laser scanning microscopy (CLSM). A total of 160 single-rooted extracted mandibular premolar teeth were divided into five groups (n = 32 each) according to the solution used in the final rinse protocol, as follows: 17% ethylenediaminetetraacetic acid (EDTA) (group 1), 17% EDTA and 2% chlorhexidine gluconate (CHX) (group 2), 7% maleic acid (MA) (group 3), 7% MA and 2% CHX (group 4), and 5.25% NaOCl (group 5). Two roots from each group were examined under scanning electron microscopy (SEM) to visualize smear layer removal. Experimental groups were then split randomly into three subgroups (n = 10) and obturated using a cold lateral condensation technique with 0.1% rhodamine B-labelled sealers [either AH Plus (group A), EndoREZ (group E), or Tech BioSealer Endo (group T)] and gutta-percha. Specimens were sectioned and observed by CLSM to evaluate the percentage and maximum depth of sealer penetration at the apical, middle, and coronal levels. Statistical comparison was performed on grouped (apical, middle, and coronal segments) and ungrouped data using two-way ANOVA with Bonferroni post hoc test (p < 0.01). AH Plus showed the greatest tubule penetration while Tech BioSealer Endo showed the least. Resin-based sealers displayed deeper and more consistent penetration. CHX irrigation positively influenced sealer tubule penetration.

Highlights

The key objective of root canal therapy is to remove microorganisms out of the root canal system to prevent recontamination
Based on the solution employed in the latest rinse process, the roots were all randomly segregated into five groups (n = 32) which include the following: (i) Group 1: 5 mL 17% ethylenediaminetetraacetic acid (EDTA) (Sigma-Aldrich, Taufkirchen, Germany) for 60 sec and 2.5 mL distilled water (ii) Group 2: 5 mL 17% EDTA for 60 sec, 2.5 mL distilled water, and 2.5 mL 2% chlorhexidine gluconate (CHX) (Drogsan, Ankara, Turkey) for 60 sec (iii) Group 3: 5 mL 7% maleic acid (MA) (Merck Chemistry, Darmstadt, Germany) for 60 sec and 2.5 mL distilled water (iv) Group 4: 5 mL 7% MA for 60 sec, 2.5 mL distilled water, and 2.5 mL 2% CHX for 60 sec (v) Group 5: 5 mL 5.25% NaOCl for 60 sec and 2.5 mL distilled water
Two roots out of each of the groups were evaluated by scanning electron microscopy (SEM) to confirm smear layer removal

Summary

Introduction

The key objective of root canal therapy is to remove microorganisms out of the root canal system to prevent recontamination. Root canal instrumentation results in a smear layer containing bacteria and debris, including necrotic tissue debris [6]. This smear layer adheres to the surface of dentin and occludes the dentinal tubules. It prevents irrigant solutions, medication, and root canal sealers from penetrating these dentinal tubules and must be removed [7]. Solutions used for this purpose include sodium hypochlorite (NaOCl), maleic acid (MA), ethylenediaminetetraacetic acid (EDTA), citric acid, and phosphoric acid.

Methods

Discussion

Conclusion