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 Table of Contents  
Year : 2022  |  Volume : 34  |  Issue : 3  |  Page : 180-183

Comparative evaluation of N-acetylcysteine and chlorhexidine as final irrigation on the push-out bond strength of different sealers: An in vitro study

Department of Conservative Dentistry and Endodontics, Al-Badar Dental College and Hospital, Kalaburagi, Karnataka, India

Date of Submission21-Mar-2022
Date of Decision07-May-2022
Date of Acceptance16-May-2022
Date of Web Publication30-Sep-2022

Correspondence Address:
Dr. Kiran Ghatole
Department of Conservative Dentistry and Endodontics, Al-Badar Dental College and Hospital, Kalaburagi - 585 102, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/endo.endo_81_22

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Aim: Using N acetyl cysteine (NAC) and Chlorhexidine as final irrigants, the study aims to examine the push out bond strength of distinct sealers.
Materials and Methods: Access and biomechanical preparation were done on decoronated 80 single-rooted teeth. Canals were alternatively irrigated using 5ml of 5.25% NaOCl and 5ml of 17% EDTA solution during instrumentation. On the basis of final irrigation procedure, the samples are divided into two groups: Group 1 – NAC and Group 2 – 2% Chlorhexidine. Using paper points, canals were dried and subdivided depending on the sealers used, Group 1A and 2A- AH plus and 1B and 2B- BioRoot RCS. Teeth were obturated and middle root sections were tested for push-out bond strength using universal testing equipment. Statistical analysis was done.
Results: NAC with AH-plus sealer had the maximum push-out strength, whereas Chlorhexidine with BioRoot RCS sealer had the lowest.
Conclusion: NAC increases the bond strength of the obturating materials as the final irrigant. NAC can be considered as a final irrigant for endodontic therapy.

Keywords: Antibacterial, chlorhexidine, pushout, sealer

How to cite this article:
Ghatole K, Indi S, Diwanji P, Janavathi, Hambire A, Thimwala A. Comparative evaluation of N-acetylcysteine and chlorhexidine as final irrigation on the push-out bond strength of different sealers: An in vitro study. Endodontology 2022;34:180-3

How to cite this URL:
Ghatole K, Indi S, Diwanji P, Janavathi, Hambire A, Thimwala A. Comparative evaluation of N-acetylcysteine and chlorhexidine as final irrigation on the push-out bond strength of different sealers: An in vitro study. Endodontology [serial online] 2022 [cited 2023 Jan 31];34:180-3. Available from: https://www.endodontologyonweb.org/text.asp?2022/34/3/180/357704

  Introduction Top

Cleaning, shaping as well as disinfection of the root canal are all critical components of successful endodontic treatment. It is done by chemomechanical preparation to remove germs and their by-products from the canal.[1]

Regardless of the kind of instrument and instrumentation method used, this procedure might result in the formation of smear layer, which is caused by the burnishing and translocating of the superficial dentin wall components. Obturation materials may not adhere completely to the canal surfaces if the root canal fillings and root canal walls are not perfectly aligned.[2] To eliminate the smear layer, irrigant solutions are essential. There are several solutions with varying concentrations and compositions.

In endodontics, NaOCl (Sodium Hypochlorite) is the most often utilized irrigant which dissolves the organic components of the smear layer, as well as necrotic tissue.[3] The most common demineralizing agent is ethylenediaminetetraacetic acid (EDTA). Due to its significant chelating impact on mineralized tissues, it is essential in cleaning tubules that were clogged during instrumentation.[4] Due to its propensity to coagulate and precipitate bacterial intracellular components, chlorhexidine gluconate (CHX) exerts a bactericidal effect and is suggested as a final irrigant.[5]

On endodontic, pathogenic bacteria, N-acetylcysteine (NAC) exerts an antibacterial property. NAC is an antioxidant with thiol groups that efficiently reduces extracellular polysaccharide synthesis, disintegrating mature biofilms and decreasing bacterial adherence in the same way that a mucolytic drug does.[6]

Irrigants with different compositions, concentrations, and exposure times may be able to change the surface of the root dentin, promote structural changes (lower the Ca/P ratio), and change surface hardness and roughness, among other variables. Different irrigant solutions may affect its interaction with the sealer utilized.[7] Consequently, the root canal walls and obturating materials may not adhere properly.

AH-Plus® (Dentsply Maillefer, Ballaigues, Switzerland) is an epoxy-amine resin-based two-component paste root canal sealer. There have been several studies that have relied on it as the reference and gold standard.[8]

RCS BioRoot is hydraulic tricalcium silicate-based powder-liquid cement. It has good adhesion and antimicrobial properties.[9]

Dislodgement of filling material can be examined by performing push-out strength tests on treated root canal dentin. Compared to the micro tensile bond test, the push-out test results have less variability and is more consistent in stress distribution.[10] Thus, the goal of this study was to examine the push-out strength of endodontic sealers utilized for teeth obturation after using final root canal irrigants such as NAC and chlorhexidine.

  Materials and Methods Top

The present study was conducted after obtaining institutional ethical clearance (Ref No: IEC/202021/29). The research included eighty single-rooted extracted teeth. Teeth extracted mainly due to periodontal problems were selected. The study included teeth with completely formed apices and straight canals, but teeth with curved roots, caries, cracks, open apices, or past root canal procedures were eliminated. The teeth were properly cleansed, disinfected, and preserved in distilled water until use. With a high-speed diamond disc and water coolant, the teeth were decoronated to create 13 mm-long root segments. K-file (Mani, Tochigi, Japan) size #10 was used to achieve canal patency. ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) was utilized to prepare the root canal in a crown-down manner as per the label instructions, utilizing a gentle in-and-out motion up to F4 size (#40/0.06).

During instrumentation, canals were irrigated passively using 5 ml of 5.25% NaOCl solution (Vishal Private Limited, India) and 5 ml of 17% EDTA solution (SmearClear; Synbron Endo, Orange, CA, United States) alternately with 30 gauge close-ended single side vented needle (Trident, India) placed passively at 1 mm short of the working length. Saline was used in between the irrigants to avoid their interactions.

Samples were then randomly divided into two groups: Group 1– NAC -NAC solution at 200 mg/mL concentration was freshly made by dissolving 0.2 g in sterile distilled water of 1 mL as described. A volume of 3 ml of NAC solution was used as the final irrigant.

Group 2 – About 3 ml of 2% chlorhexidine (Vishal Dentocare Pvt. Ltd, Ahmedabad, Gujarat, India) was utilized as the final irrigant.

Paper points were utilized to dry the canals until they seemed completely dry. Sealers were mixed as per the label instructions. Based on the sealer used, the groups were subdivided into subgroups 1A and 2A-AH-plus and 1B and 2B-BioRoot RCS. Obturation with F4 gutta-percha and incubation at 37°C for 1 week and 100% relative humidity allowed the sealer time to harden.

Push-out bond strength test

The long axis of the root canal was perpendicularly cooled with freshwater, while a circular diamond disc sectioned each root block horizontally at low speed. Two sections each having 2 mm thickness were cut at 3, 7, mm from the coronal part of the root. Specimens were mounted in a custom-made loading fixture. Using a plunger with a diameter of 1.2 mm and a speed of 1 mm/min, the specimens were put on a metal slap with a center hole for free movement. The plunger tip was put in such a way that it only came into touch with the test material. The test was repeated until the bond was failure completely. Megapascal was the maximum force applied to materials at dislodgment time.

Statistical analysis

One-way ANOVA was used to determine standard deviation and mean for both groups and subgroups. Groups were compared using Tukey post hoc test with the significance level at P < 0.05 [Table 1] and [Table 2].
Table 1: Mean and standard deviation for both the groups and subgroups P value e by using one way ANOVA

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Table 2: P value using Tukey post hoc test to compare two subgroups

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  Results Top

It was shown that Group 1-NAC had a stronger bond than Group 2. The result of subgroups showed AH-Plus sealer having better bond strength than BioRoot RCS sealer in both the groups.

  Discussion Top

Eradication of bacteria from the root canal by endodontic therapy is challenging due to biofilm deposition on the dentin walls and the root canal anatomy. Thus, one of the main objectives is to find effective methods for limiting the occurrence of microorganisms.[11] Prevention of coronal leakage into periradicular areas is also of prime importance to avoid reinfection. Hence, antibacterial irrigants are used to reduce biofilm and enhance adhesion to the root canal.[12]

Extracted teeth were used in this study as closely simulate the clinical situations. As the bond strength remained unaffected with distilled water, it was used to keep the collected teeth.[13]

Berber et al. showed no differences between different NaOCl concentrations in lowering Enterococcus faecalis in root canal lumen, but only with greater concentrations can disinfect dentinal tubules using sodium hypochlorite, which is utilized as an irrigant for its antibacterial effect.[14] The best method for removing the smear layer is EDTA.[15] Dogan et al. showed EDTA decreases the surface energy of the root canal wall which may provide a required dentin substrate for the material adhesion.[16] Hence, alternate use of sodium hypochlorite and EDTA irrigation was followed in this study.

CHX gluconate is a biguanide disinfectant with wide antibacterial substantive action against E. faecalis and other resistant bacteria.[17] It can be adsorbed on hydroxyapatite surfaces and gradually released. It is also efficient against yeasts and bacteria of Gram +ve and Gram −ve types.[18] However, Portenier et al. showed dentin inhibits the antibacterial activity of chlorhexidine.[19] Hence, a new irrigant NAC was used in the study as a final irrigant.

NAC is an amino acid derivative of L-cysteine, a thiol-containing antioxidant with antibacterial properties. It destructs the disulfide bonds in proteins damaging the bacterial proteins. It is an anti-inflammatory nonantibiotic drug.[20] The antibacterial activity of NAC has remained unchanged with the presence of dentin, according to Quah et al., which is an additional benefit over chlorhexidine.[21]

NAC was shown to have higher bond strength than chlorhexidine in this study. This could be because NAC reduces extracellular polysaccharide production which in turn increases the obturating material adhesion to the root dentin walls.[22] Abbott PV showed chlorhexidine has less soluble substances which tend to leave residues of the canal walls affecting the sealing.[23]

The bond strength of NAC with AH-Plus sealer was greater than NAC with bioceramic sealer. According to Amin et al., AH-plus possesses acceptable physicochemical properties, including low disintegration and solubility, long-term dimensional stability, and excellent apical seal ability and adhesion, all of which contribute to increased bond strength.[24] Barbosa AFS also showed that resin-based sealers had better root canal dentin retention and stronger push-out strength in comparison to other endodontic sealers.[25] AH-plus sealer showed better bond strength than BioRoot RCS when chlorhexidine was used final rinse. This might be due to the epoxy resin's covalent bonds with the amino groups of the dentinal collagen, resulting in strong bonds, whereas BioRoot RCS has micromechanical interaction and forms tag-like structures.[26],[27] The “mineral infiltration zone's” chemical interaction creates a weak bond, which might lead to low bond strength. The results are consistent with Neelakantan et al. and Fisher et al.[28],[29]

The bond strength was evaluated by a push-out technique as it is reliable, precise, and convenient for statistical analysis. In this study, 2-mm thick specimens were used as the probability of nonuniform stress would be removed.[30]

  Conclusion Top

N-acetylcysteine may be utilized as the final endodontic irrigant on the basis of the findings of this in vitro study, which has few limitations.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

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  [Table 1], [Table 2]


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