Effect Of Sodium Hypochlorite Research Articles

Effect of sodium hypochlorite, ethylenediaminetetraacetic acid, and dual-rinse irrigation on dentin adhesion using an etch-and-rinse or self-etch approach

The aim was to investigate the influence of endodontic irrigation solutions and protocols on the micro-tensile bond strength (μTBS) to dentin using an etch-and-rinse (ER) or self-etch (SE) adhesive approach. Eighty extracted human molars were ground to dentin. After pretreating for 27 min (21 min–3 min–3 min) with five different endodontic irrigation protocols (Group 1: NaOCl–EDTA–NaOCl; Group 2: NaOCl–NaOCl–EDTA; Group 3: NaOCl–NaCl–NaOCl; Group 4: Dual Rinse–Dual Rinse–Dual Rinse; Group 5: NaCl–NaCl–NaCl), an ER (Optibond FL, Kerr) or a SE (Clearfil SE Bond, Kuraray) adhesive system was applied. After light-curing, composite build-ups were made and cut into dentin-composite sticks. μTBS and failure modes were analyzed. Nonparametric statistical analyses (α = 0.05) were performed for comparison of the five groups within each type of adhesive as well as between the two adhesive systems used. The use of an ER instead of a SE adhesive system resulted in significantly higher μTBS for all irrigation protocols except for group 1 (NaOCl–EDTA–NaOCl) and 2 (NaOCl–NaOCl–EDTA). A statistical difference between the five different endodontic irrigation protocols was only found within the SE adhesive group, where group 1 (NaOCl–EDTA–NaOCl) achieved highest values. The use of an ER adhesive system cancels out the effect of the endodontic irrigation solution. The highest μTBS was achieved when using a NaOCl–EDTA–NaOCl-irrigation protocol in combination with Clearfil SE Bond, which shows that the selection of the endodontic irrigation should match the corresponding SE adhesive system.

Effect of sodium hypochlorite and calcium hypochlorite on the apical sealing ability of endodontic sealers

Aim: This study aimed to compare the influence of sodium hypochlorite (NaOCl) and calcium hypochlorite [Ca(OCl)2 ] on the apical sealing capacity of AH Plus (Dentsply Maillefer) and Bio-C Sealer (Angelus) endodontic sealers. Methods: Sixty permanent human lower incisors were randomly allocated (http://www.randomized.org), according to the irrigant used, into three groups (n=20): 0.9% sodium chloride (NaCl/Control); 2.5% NaOCl; and 2.5% Ca(OCl)2 . The root canal was prepared with rotary files under 10 mL of the solution corresponding to the experimental group. Each group was subdivided into two (n=10) according to the sealer used for filling: AH Plus (Dentsply Maillefer) or Bio-C Sealer (Angelus). Then, all samples were immersed in black India ink for one week. After the storage period, the roots were then grooved longitudinally and split, and the ink penetration was measured from the apical part to the coronal part of the root canal into which the ink penetrated using a stereomicroscope. Data were analyzed by one-way ANOVA and Tukey’s post-hoc tests. Results: There was no statistical difference in ink penetration between the different endodontic sealers tested for the same irrigating solution (p > 0.05). However, when the Bio-C Sealer (Angelus) was used, the group treated with 2.5% Ca(OCl)2 was associated with lower values of apical leakage, compared to 2.5% NaOCl (p < 0.05). For the AH Plus sealer (Dentsply Maillefer), there was no difference between the irrigants (p > 0.05). Conclusions: Associating Ca(OCl)2 irrigant with Bio-C Sealer (Angelus) seems to be a good option to reduce apical leakage.

Effect of sodium hypochlorite and ethylenediaminotetraacetic acid activated by laser and ultrasonic energy on surface morphology and chemical composition of intracanal dentin.

The aim of the study was to evaluate the structural and chemical changes in intracanal dentin after root canal irrigation with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) using additional activation with a novel Er:YAG Shock Wave-Enhanced Emission Photoacoustic Streaming (SWEEPS), ultrasonic irrigation (UI), and Nd:YAG irradiation. Root canals of extracted human premolars were instrumented with distilled water and distributed into groups according to the irrigation protocol used: Group 1: conventional needle irrigation (CI) with 3% NaOCl; group 2: CI with 15% EDTA; and group 3: CI with NaOCl+EDTA. In group 4, root canals were irrigated with NaOCl+EDTA+NaOCl using the following techniques: CI (group 4A), SWEEPS (group 4B), UI (group 4C). In group 4D, root canals were finally irradiated with Nd:YAG laser. After the irrigation, the intracanal dentin sample was collected and analyzed using spectroscope with a Fourier transformation of infrared spectrum in Attenuated total reflection technique (FTIR-ATR) to calculate apatite/collagen ratio. Scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS) were used to determine its chemical composition. FTIR-ATR showed no significant difference in the phosphate/amid I ratio between the control and the experimental groups (p > 0.05). SWEEPS and UI of NaOCl+EDTA+NaOCl caused the most pronounced decrease of Ca and P (p < 0.05) value compared to CI and control group, and canal wall erosion. SWEEPS and UI of NaOCl+EDTA+NaOCl caused the most pronounced decrease of Ca and P value and significant canal wall erosion. However, no difference in phosphate/amide ratio was reported among groups. RESEARCH HIGHLIGHTS: SWEEPS and UI of NaOCl+EDTA+NaOCl caused the most pronounced decrease of Ca and P values and significant canal wall erosion. There was no difference in phosphate/amide ratio among the irrigation protocols.

Effect of Sodium Hypochlorite on the Microbiota and Odor of Manure Effluents

Effect of Sodium Hypochlorite on the Microbiota and Odor of Manure Effluents

Antimicrobial Efficacy of Sodium Hypochlorite and Er, Cr: YSGG Laser against E Faecalis Biofilm - A Systematic Review

Background: The complexity of the root canal system makes it difficult to completely disinfect is the leading cause for endodontic retreatment. Sodium hypochlorite (NaOCl) is the traditionally used irrigation solution and has improved its efficacy with various adjuncts. The use of lasers in disinfecting the canal system has come into prominence in recent years. Aim: To assess the efficacy of sodium hypochlorite and Er, Cr: YSGG laser against E faecalis biofilm. Methodology: A systematic search was conducted using a search strategy in PubMed and Google scholar for studies published between 1st January 2011 and 21st March 2022. Hand searching of relevant articles in Institutional library was also performed. Comparative in vitro studies in English language or articles in other languages which had a possibility of translation into English comparing sodium hypochlorite and Er, Cr: YSGG laser for irrigation against E faecalis biofilm were included in the review whereas, studies comparing efficacy against biofilm other than E faecalis, comparison with other laser activated intracanal irrigation, data reported through letter to editors, short communications and conference proceedings were excluded from the review. Results: A preliminary search yielded a total of 67 studies of which seven articles giving 11 estimates were included for qualitative synthesis. Data on colony forming units for both the groups (sodium hypochlorite and Er, Cr: YSGG laser) was extracted. Overall, four studies presented significant difference in the effectiveness of sodium hypochlorite and Er, Cr: YSGG laser whereas three studies presented with no difference among the two groups. Conclusion: Irrigation of root canal by sodium hypochlorite and Er, Cr: YSGG laser activation both prove to be effective in reducing the E faecalis colony forming units. However, it is difficult to provide a conclusive statement on the superiority of Er, Cr: YSGG laser activated irrigation over sodium hypochlorite solution as half of the studies gave contrasting results. Future studies with larger sample size on complex anatomical root structure are recommended.

Effect of sodium hypochlorite on the microbiota and odor of manure effluents

Manure effluents (ME) of livestock enterprises represent a rich nutrient medium for the development of various aerobic microorganisms (MO). During the biodegradation of the organic components of ME, a wide range of odor-forming substances (OFS) and greenhouse gases enter the atmospheric air. The intensity and main directions of ME destruction depend on the composition and amount of microbiota. A solution of sodium hypochlorite can be used to suppress the decomposition of the biogenic components of ME. In the course of our research, it was found that the introduction of 0.005% active chlorine into the liquid fraction of ME (pH ~ 6.8; humidity ~ 99.1%) leads to a decrease in the numbers of putrefactive microbiota, namely: Bacteroides, Clostridium, Escherichia coli, Pseudomonas, Sarcina ventriculi, and Peptostreptococcus anaerobius. The corresponding ammonifiers are actively involved in the biodegradation processes of organic substances to form acetic acid, isovaleric acid, butyric acid, indoles, skatoles, ammonia, hydrogen sulfide, mercaptans and others. The numbers of microbiota not making a significant contribution to the production of OFS (Saccharomyces cerevisiae, Rhodotorula glutinis, Lactobacillus ssp. and others), on the contrary, increased. The numbers of some producers of volatile fatty acids (VFA), namely: Anaerococcus prevotii, Acidaminococcus, Prevotella spp. etc. increased. However, this did not affect the intensity and nature of the ME odor, which can be explained by the formation of non-volatile VFA salts at pH above 7.0. The numbers of Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella sp., Proteus ssp., Alistipes putredinis, Bifidobacterium ssp., Candida tropicalis, and Candida albicans almost did not change when NaOCl was added to ME. As a result of the microbiota transformation, the total emission of gaseous substances, whose main components are the greenhouse gases CO2 and CH4, decreased by more than 17%. The unpleasant odor intensity has significantly decreased. A NaOCl solution can be used to treat ME in manure storage baths. The introduction of the practice of treating ME with this biocide is facilitated by its availability, low cost and safety for the environment.

Effect of sodium hypochlorite as a depressant for copper species in Cu-Mo flotation separation

One alternative to replace conventional depressants in Cu-Mo separation is using oxidizing agents to promote the formation of products on chalcopyrite that render its surface hydrophilic and thus favor its depression. This work provides a study to understand how sodium hypochlorite can act as a depressor for chalcopyrite in Cu-Mo flotation separation. The effect of NaClO in flotation tests was evaluated by means of electrochemical techniques, scanning electron microscopy (SEM), Fourier transform infrared analysis and contact angle measurements. The flotation results showed a selective depressant effect at a dosage of 1,020 g/t NaClO, conditioning time of 5 min, and pH 7. The mixed potential showed that the oxidation of chalcopyrite and molybdenite is possible through the addition of NaClO. The SEM observations showed changes in oxidized chalcopyrite morphology, which is supported by the decreasing contact angle change; no morphological changes were observed on molybdenite. FTIR analyses showed the characteristic peaks of the OH group after chalcopyrite was treated with NaClO; when molybdenite was treated with NaClO, the FTIR spectrum did not show changes. A scheme is proposed for the formation of oxidation species.

Effect of Sodium Hypochlorite 0.05% on MMP-9 Extracellular Release in Chronic Wounds.

In chronic wounds, high concentrations of matrix metalloproteinases (MMPs) can cause excessive proteolysis and slow wound healing. Consequently, restoring a proper MMP balance can help reduce the risk of a chronic wound. An antiseptic solution containing 0.05% sodium hypochlorite (Amukine Med 0.05%, Angelini S.p.A.; hereafter termed NaClO solution) is available on the market. The NaClO solution was proven effective and safe in managing infected skin wounds. To further characterize its activity, this study evaluated the in vitro activity of the NaClO solution on the monocyte release of MMPs. Human monocytic THP-1 (ATCC® TIB-202™) cell lines were differentiated into macrophages and treated with different concentrations of NaClO (from 0.05% to 5 × 10-7%). In addition, the THP-1 cell line was stimulated with wound fluid (WF) from patients with active venous leg ulcers in the inflammatory phase. The effect of NaClO (0.025-0.0062%) was also evaluated on healthy human peripheral blood serum samples. The effects of treatments on the gelatinolytic activity of MMP-9 were evaluated by gelatin zymography. The effects on MMPs release were evaluated through the Pro™ Human MMP 9-plex Assay. An exploratory scratch wound healing assay was also performed. The NaClO solution reduced the gelatinolytic activity of MMP-9 and its activated form. The downregulation of MMP-9 gelatinolytic activity was also observed in peripheral blood serum. The MMPs profile showed a reduction in MMP-1 release (p < 0.05) and a slight reduction of the release of MMP-9 and MMP-12 after the treatment with LPS and the NaClO solution. A slight improvement in wound healing was observed after macrophage activation and treatment with the NaClO solution. The results obtained suggest a possible ability of the NaClO solution to modulate the proteolytic pathways in the wound microenvironment, further characterizing its activity and use in clinical practice during wound care.

Effect of Sodium Hypochlorite on Biofilm-Producing Organisms Isolated from A Hospital Drinking Water

Objectives: Providing safe drinking water is essential for maintaining healthcare quality. The presence of biofilms in the water supply protects the organism from the antimicrobial effects of disinfectants leading to the formation of the MDR pathogen pool. Therefore, this study was taken up to determine the prevalence of biofilm formation in the bacteria isolated from the water system of a tertiary health care setup and study the effect of disinfectants on biofilms.&#x0D; Methods: Thirty-four drinking water samples were collected in sterile glass stopper bottles and transported to the lab. Standard bacteriological procedures identified isolates. Biofilm detection was carried out by the tissue culture plate (TCP) method. The effect of disinfectant (sodium hypochlorite) at various concentrations (0, 0.25, 0.5, 1, 2, and 4 %) on biofilm-producing organism were studied for 30 minutes and analyzed.&#x0D; Results: The culture positivity was 76.4% (26/34). Twenty samples showed monomicrobial growth, while only six samples showed polymicrobial growth of organisms. The most common organism isolated was Pseudomonas aeruginosa. Biofilm production was seen more in polymicrobial organisms, 91.66 % (11/12). A high level of resistance to chlorine compounds was seen in biofilm-producing microorganisms, especially those that produced robust biofilms.&#x0D; Conclusion: Resistance of biofilms against high levels of chlorine has implications for the delivery of safe drinking water. Drug resistance was seen in these organisms, which can be transmitted from drinking water sources to humans. Therefore, it is recommended that biofilm production should be evaluated in drinking water samples regularly..J Microbiol Infect Dis 2022; 12(4):17-24.

Adhesive bonding on the endodontically treated tooth

Endodontic irrigants negatively influence the physical properties of dentine. The effect of sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA) on the bond strength to dentine was investigated in a systematic review. Inclusion criteria were the following: a microtensile or microshear test, the irrigants sodium hypochlorite and/or EDTA, an irrigation time of ≥ 5 minutes of sodium hypochlorite, an irrigation protocol for endodontic treatment, human dentine, the presence of a control group and no post space preparation. Of the 188 eligible articles, 13 were suitable for inclusion. There was strong evidence that rinsing with sodium hypochlorite and also additional rinsing minutes with ethylenediaminetetraacetic acid leads to minimum bond strength to dentin for a two-step self-etching adhesive. For a two-step etch-and-rinse adhesive, the bond strength is approximately significant after rinsing with sodium hypochlorite (rinsing time: 10-60 minutes).

Effect of Sodium Hypochlorite and Ethylene Diamine tetra-acetic acid on The Push-out Bond Strength and Sealing Ability of Different Bioceramic Root Repair Materials. (In Vitro Study)

Effect of Sodium Hypochlorite and Ethylene Diamine tetra-acetic acid on The Push-out Bond Strength and Sealing Ability of Different Bioceramic Root Repair Materials. (In Vitro Study)

Effectiveness of sodium hypochlorite and peracetic acid for spoilage-causing molds on sweet potato slices

Effectiveness of sodium hypochlorite and peracetic acid for spoilage-causing molds on sweet potato slices

Effect of Sodium Hypochlorite and Hypochlorous Acid Solutions on the Cyclic Fatigue Resistance of Waveonegold, K3XF and Hyflex-EDM: A Study of Metallurgical Properties

Effect of Sodium Hypochlorite and Hypochlorous Acid Solutions on the Cyclic Fatigue Resistance of Waveonegold, K3XF and Hyflex-EDM: A Study of Metallurgical Properties

The Investigation of the Efficacy of Some Antiseptics and Disinfectants to Vancomycin-Resistant Enterococci

Disinfection of contaminated material, surface and body parts with appropriate substances is one of the most effective practices in preventing the infection-colonization of Vancomycin-Resistant Enterococci (VRE). In this study, 1/10 and 1/100 dilutions of 5% sodium hypochlorite, 4% concentration of chlorhexidine gluconate and 0.1% and 0.5% concentrations of Akacid plus’s efficacy against VRE strains at 1, 5, 15 and 30 minutes was tested. Sixty-nine vancomycin-resistant E. faecium strains isolated from different body samples between 2012 and 2014 were included in the study. The BD Phoenix 100® fully automated system was used for the identification of strains and detection of vancomycin resistance. Quantitative Suspension Test method EN 1276 (March 2010) was used to evaluate the bactericidal activities of chemical disinfectants and antiseptics used in European Union countries in the investigation of disinfectant susceptibility of VRE strains. Five log10 decrease (105) in the number of bacteria in the initial test suspension between the number of bacteria after using the disinfectant indicates that the disinfectant is effective. In this study, it has been determined that a 1/10 dilution of 5% sodium hypochlorite (bleach) is the most effective disinfectant on VREs in all minutes and conditions. Effectiveness of 1/100 dilution of bleach has a significant decrease in dirty conditions. Akacid plus was not effective on all strains in any contact times we tested. It has been observed that Akacid plus is the disinfectant least affected by the changes in environmental conditions in all minutes. Chlorhexidine gluconate (4%) was ineffective in clean and dirty conditions in just 1 minute, while from the 5th minute, its effectiveness was found to be statistically at the same level as the 1/10 dilution of bleach. There was no decrease in the activities of chlorhexidine due to the changing environmental conditions. In conclusion, it has been determined that a 1/10 dilution of 5% sodium hypochlorite (bleach) is the most effective disinfectant on VREs in all minutes and conditions, but dirty environmental conditions cause a significant decrease in the effectiveness of sodium hypochlorite. In addition, it was observed that the effectiveness of all disinfectants and antiseptics on VREs increased as the contact time with the substances increased.

Effect of sodium hypochlorite on bonding performance of universal adhesives to pulp chamber dentin

Abstract Background/purpose The most widely utilized irrigation solution in endodontic therapy is sodium hypochlorite (NaOCl). The purpose of this study was to assess the effects of NaOCl on the bond strength of four universal adhesives and one two-step self-etch adhesive to pulp chamber dentin. One hundred sixteen extracted sound human third molars were used in this study. All the teeth were divided into two groups: (1) with NaOCl treatment and (2) without NaOCl treatment. These two groups were subdivided into five bonding groups: G-Premio Bond (GP), Beautibond Xtreme (BBX), Scotchbond Universal (SBU), Clearfil Universal Bond Quick (UBQ), and Clearfil Megabond 2 (MB2). The microtensile bond strength (μTBS), the fracture mode analysis, resin-dentin interface and dentin surface were observed by SEM. Two-way ANOVA was performed to analyze the μTBS (α = 0.05). The μTBS of the NaOCl group significantly decreased for GP and MB2 ( P < 0.05). Significant effects of adhesive (F = 12.182, P < 0.001), and irrigation (F = 27.224, P < 0.001) on the μTBS were observed, whereas interaction between adhesive and irrigation was not significant (F = 1.761, P = 0.144). The adhesive layer with variable thickness was observed in all groups with different morphological structures. The effect of NaOCl treatment on the μTBS differs depending on the type of adhesives.

Effect of Sodium Hypochlorite in Dental Unit Waterline on Aerosolized Bacteria Generated from Endodontic Procedures

IntroductionAerosol generation in a dental setting is a critical concern, and approaches that aim at decreasing bacterial load in aerosols are of high priority for dental professionals. The objectives of this study were to evaluate the relative effect of various endodontic procedures on the generation and dissemination of aerosols and the effect of 0.1% sodium hypochlorite (NaOCl) in dental unit waterlines (DUWLs) on the bacterial load in the generated aerosols in a clinical setting. MethodsThe study was completed in 2 phases. The classic passive sampling technique using brain-heart infusion agar plates was used. Agar plates were strategically placed throughout the operatory at predefined locations. In phase 1, to evaluate the effect of different endodontic procedures on the generation and dissemination of aerosols, we collected a total of 38 samples. After baseline collection, test samples were collected during vital pulp therapy (VPT) full pulpotomy (n = 10), nonsurgical root canal therapy (NSRCT, n = 10), surgical root canal therapy (SRCT, n = 10), and incision and drainage (n = 8) procedures. Bacterial growth was expressed as colony-forming units at 48 hours after sample collection. Data were analyzed using 1-way analysis of variance with the Tukey multiple comparison post hoc test. In phase 2, to evaluate the effect of 0.1% NaOCl in the DUWL on the bacterial load in the generated aerosols, a total of 30 samples were collected. All procedures including VPT (n = 10), NSRCT (n = 10), and SRCT (n = 10) were performed with 0.1% NaOCl in the DUWL. Bacterial growth was expressed as colony-forming units at 48 hours after sample collection. Data were analyzed using 2-way analysis of variance with the Tukey multiple comparison post hoc test. ResultsAll endodontic procedures generated aerosols at all tested locations, except incision and drainage. Aerosols were disseminated as far as 3 m from the patient's head with no significant difference between various locations (P > .05). VPT procedures generated the maximum number of aerosols compared with NSRCT and SRCT. Adding 0.1% NaOCl to DUWLs significantly reduced the bacterial load in the generated aerosols in all treatment groups compared with groups treated with untreated waterlines (P < .05). No significant difference was noted in the bacterial load between all groups with treated waterlines (P > .05). ConclusionsAll tested endodontic procedures led to the generation and dissemination of contaminated aerosols, and the addition of 0.1% NaOCl as a biocide to the DUWL led to a statistically significant reduction in the bacterial load.

Effect of Sodium Hypochlorite (NaOCl) for Pretreatment of Early Demineralized Enamel Lesions in Enhancing the Remineralization Capacity of Self-assembling Peptide (In-vitro Study)

Effect of Sodium Hypochlorite (NaOCl) for Pretreatment of Early Demineralized Enamel Lesions in Enhancing the Remineralization Capacity of Self-assembling Peptide (In-vitro Study)

Rapid germination and development of Acacia sieberiana DC in vitro

Acacia sieberiana is an ecological and economical important forest tree. The plant has poor germination due to dormancy; therefore, in vitro culture can provide a fast supply of plantlets and can be a basis for further biotechnology research. The effect of sodium hypochlorite, Murashige and Skoog (MS) medium, sucrose and cytokinin were investigated. The results indicated that all the treatments induced significant (P &lt; 0.05) effects on germination and seedling development depending on their concentrations. Germinates free of contamination were established successfully with all the concentrations of sodium hypochlorite, however, the germination was reduced as the concentration increased. A higher germination rate of 98.3% was attained with full MS strength and 3% sucrose concentration. The highest germination percentage obtained was 100% with 2 mg/L thidiazuron. The maximum shoot length (13.5 cm) and seedling dry weight (0.49 g) were recorded on full MS medium while the maximum root length (13.4 cm) was obtained on ½ MS strength. However, when full MS medium augmented with 5% sucrose enhanced shoot length and dry weight to (14.2 cm) and (0.5 g), respectively. While the highest root length (10.2 cm) was obtained by 3% provided in full MS medium. Application of cytokinins improved the number of node and dry weight of seedlings to 6.9 nodes with 4 mg/L thidiazuron and 0.54 g by 2 mg/L benzyladenine. The present study describes the establishment of in vitro seed germination and seedling growth system for A. sieberiana for the first time.

Effect of Lowering the pH of Sodium Hypochlorite on Control of Pseudomonas aeruginosa in Maintenance of Pharmaceutical Water System

Drinking water or potable water is a common source for generation of purified water or demineralized water which is used for processing of medicinal products such as tablets, capsules, syrups, and nasal sprays. Before allowing for purification, it is manufacturer’s responsibility to ensure the microbial load control in the source water to get good quality product water and to avoid biofilm formation in waterlines. The current research involves the study of an effectiveness of sodium hypochlorite (NaOCl) at various concentrations of water pH on microbial control by following pour plate technique. The aim of this study was to examine the effect of lowering the pH on the recovery of Pseudomonas aeruginosa. Three groups were tested by challenging known population of P. aeruginosa by varying the pH of 5.0, 7.0 and 9.0. No significant difference was observed at pH 5.0 and 7.0 and the recovery increased when the pH increased at 9.0. Effective microbial control was obtained at neutral pH. The increase of pH resulted decrease of effectiveness of NaOCl.

Effect of sodium hypochlorite, isopropyl alcohol and chlorhexidine on the epoxy sealant penetration into the dentinal tubules.

The sealer penetration into the dentinal tubules might be beneficial, especially in necrotic endodontic cases, as it provides the obstruction of the contaminated tubules. To determine the effect of 3 final irrigants (sodium hypochlorite (NaOCl), alcohol and chlorhexidine (CHX)) on the penetration of an epoxy sealer into the dentinal tubules. The study was carried out on 60 single-canal human teeth with straight roots. The root canals were prepared to the ISO 40/04 size, using the Reciproc® instruments. The teeth were divided into 4 groups (n = 15). The canals in each group were irrigated according to the following scheme: group 1 (control) - 5.25% NaOCl; group 2 - smear layer removal (40% citric acid (CA) and 5.25% NaOCl) and 5.25% NaOCl; group 3 - smear layer removal (as in group 2), and 40% CA, water and 98% isopropyl alcohol; and group 4 - smear layer removal (as in group 2), and 40% CA, water and 2% CHX. The root canals were filled using the vertical condensation technique with gutta-percha and the porphyrin-labeled AH Plus™ sealer. After 3 days, 1-milimeter-thick cross-section slices were cut from the roots at a distance of 2 mm, 5 mm and 8 mm from the apex. The sections were imaged under a confocal microscope and the sealant penetration depth into the dentinal tubules was measured. The longest resin tags in all parts of the roots were found in group 4 (CHX), and the shortest in group 1 (control). The mean depth of the sealer penetration (in micrometers) was as follows: 21, 22 and 23 (group 1); 201, 231 and 374 (group 2); 170, 232 and 280 (group 3); and 330, 408 and 638 (group 4) in the apical, middle and coronal parts, respectively. The final irrigation with CHX resulted in the deepest penetration of the epoxy sealer into the tubules. Isopropyl alcohol had the most negative impact on the sealer penetration into the tubules.