Effect of EDTA, NaOCl, and HEDP-based irrigants on the mechanical properties of heat treated NiTi endodontic instruments

The purpose of this study was to evaluate the efficiencies of different irrigation protocols in the removal of triple antibiotic paste (TAP) from root canals. A total of 127 extracted human maxillary incisor teeth were prepared. Then, root-end resection of 3 mm was accomplished to simulate immature apex model. The root canals were filled with TAP, after 21 days, randomly divided into nine groups according to irrigation systems and solutions (n = 13). Conventional irrigation (CI) groups - Group 1: Root canal irrigation was performed with CI by Peracetic acid (PAA) solution, Group 2: Root canal irrigation was performed with CI by etidronic acid 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) + sodium hypochlorite (NaOCl) solution, Group 3: Root canal irrigation was performed with CI by ethylenediaminetetraacetic acid (EDTA)/NaOCl solutions. Vibringe system groups - Group 4: Root canal irrigation was performed with Vibringe system by PAA solution, Group 5: Root canal irrigation was performed with Vibringe system by HEBP + NaOCl solution, Group 6: Root canal irrigation was performed with Vibringe system by EDTA/NaOCl solution. EndoVac system groups - Group 7: Root canal irrigation was performed with EndoVac system by PAA solution, Group 8: Root canal irrigation was performed with EndoVac system by HEBP + NaOCl solution, Group 9: Root canal irrigation was performed with EndoVac system by EDTA/NaOCl solution. Control Group: (n = 0). Samples were sectioned vertically, and the amount of remaining medicament was scored for each root half and data were statistically analyzed. Among the irrigation systems, CI groups showed the highest scores at both apical and coronal parts (P < 0.05). In comparisons among the solutions, at the apical part, PAA groups showed the highest scores (P < 0.05). At the coronal part, EDTA + NaOCl groups showed the lowest score values (P < 0.05). The use of irrigation systems improved the removal of TAP from the simulated immature root canals. Also, as an irrigation solution EDTA gives more promising results than PAA and HEBP solutions.

Mixture tetracycline citric acid and detergent – A root canal irrigant. A review

The aim of this study was to assess the cleaning capacity of the octenidine hydrochloride (OCT) used as root canal irrigant by scanning electron microscopy (SEM) analysis. Sixty human unirradicular extracted teeth were randomly distributed in 6 groups (n = 10) according to irrigant solutions which were used during root canal preparation: G1, 0.1% OCT; G2, 2% chlorhexidine (CHX); G3, 2.5% sodium hypochlorite (NaOCl); G4, OCT + 17% ethylenediaminetetraacetic acid (EDTA); G5, 2.5% NaOCl + 17% EDTA and G6, distilled water. All specimens were instrumented with ProTaper system up to F4. Teeth were sectioned and prepared for SEM. The smear layer was evaluated using a 5-score system and the data were analyzed by Kruskal-Wallis and Dunn (α = 0.05). In all root canal thirds there was no significant difference between OCT, CHX, NaOCl, and water groups (p > .05), and these groups showed higher smear layer values than NaOCl + EDTA and OCT + EDTA groups (p < .05). There was no significant difference between NaOCl + EDTA and OCT + EDTA groups (p > .05). It was concluded that OCT used as a single root canal irrigant presented poor cleaning capacity and could be used in association with a final irrigation with EDTA to obtain smear layer removal.

The aim of this study was to evaluate the influence of irrigation protocols on the bond strength of a glass fiber post bonded to dentin using two resin cements. In 200 root-filled teeth, post space was prepared and divided into five groups (n = 40) based on the irrigation protocol: group 1 (3% sodium hypochlorite), group 2 (3% sodium hypochlorite – 17% Ethylene diamine tetraacetic acid), group 3 (a mixture of sodium hypochlorite and etidronic acid), group 4 (sodium hypochlorite – QMix), and group 5 (distilled water). Samples were subdivided into two subgroups (n = 10) and fiber posts were cemented using subgroup A (Self-adhesive dual-cure resin cement; SEA) or B (dual-cure resin cement following an etch-and-rinse protocol, ER). Push-out bond strength was performed after 24 h and four months (n = 10) and failure modes were categorized. Statistical analysis of data was carried out by appropriate analyses (p < 0.05). The irrigation protocol and the resin cement had a significant impact on push-out bond strength. Subgroup A group showed lower bond strength than B at both time periods when 3% NaOCl–17% EDTA and 1:1 mixture of 6% NaOCl + 18%EA protocols were used. Three percent NaOCl used in combination with 17% EDTA or QMix significantly decreased the push-out bond strength of ER at the end of four months (p < 0.05). In conclusion, dual-cure resin cements bonded with etch-and-rinse protocol showed highest bond strength when a mixture of NaOCl and etidronic acid was used as root canal irrigant. These values were differentially influenced by time.

Introduction: Smear layer is formed by organic and inorganic components generated during endodontic instrumentation. Smear layer has many deleterious effects on the success of root canal treatment. So removal of smear layer is advocated. Sodium Hypochlorite (NaOCl) and a chelating agent like Ethylene Diamine Tetra Acetic Acid (EDTA) or Citric Acid is commonly used alternatively to remove smear layer. But the alternate use increase dentine erosion in root canal surface. This in vitro study attempts to compare the smear layer removal efficacy of 15% EDTA &amp; 10% Citric Acid as a final rinsing solution. Materials and Methods: Forty extracted, single rooted and single canal human anterior tooth were used. Endodontic preparation of the root canal was done after grouping and access cavity preparation. Final irrigation was given with 15% EDTA &amp; 10% Citric Acid to the test groups and distilled water control groups and kept for one minute. Photomicrograph of the root canal surface at 3000X magnification at coronal, middle and apical regions were taken with the help of SEM and scoring for smear layer removal was done. Data was analyzed using SPSS version 16 and were compared with the control samples and subjected to statistical analysis by one way ANOVA and Bonferroni multiple comparison tests at 5% level of significance. Result: The test solutions removed smear layer but none could be removed completely from all of the three root canal regions. 10% Citric Acid removed smear layer better from the coronal and middle region but in apical region 15% EDTA produced a better result. The difference of smear layer removal efficacy of 15% EDTA &amp; 10% Citric Acid with the Control solution was found statistically significant (p&lt;0.001) but in between 15% EDTA &amp; 10% Citric Acid it was not significant in all three root canal regions. Conclusion: Regarding the smear layer removal efficacy of 10% Citric Acid was found better as a final rinse solution. Update Dent. Coll. j: 2023; 13(2):9-14

Aim: The aim is to evaluate the inflammatory response of root canal irrigants such as sodium hypochlorite, mixture of sodium hypochlorite (NaOCl) with ethylenediaminetetraacetic acid (EDTA) versus a new root canal irrigant mixture of tetracycline isomer, an acid, and a detergent (MTAD). Materials and Methods: Eighteen Charles foster rats were injected with 0.1 ml of the irrigant solution; normal saline served as control. Biopsies of the skin were obtained at 2 h, 2 days, and 2 weeks. The chronic and acute inflammatory responses were studied in specimen. Results: Three percent NaOCl-induced maximum acute inflammatory response, followed by mixture of 3% NaOCl with 17% EDTA. MTAD did not evoke any significant acute inflammatory response. All the irrigants evoked almost equal chronic inflammatory reaction. During 2 h study 3% NaOCl, being the most inflammatory, mixture of 3% NaOCl with 17% EDTA being the least inflammatory. Chronic inflammatory reactions further aggravated in each treatment group at 2 days except in MTAD-treated rats skin which sloughed before 2 weeks with no sign of resolution of chronic inflammation. Conclusion: This study suggests that NaOCl evokes rapid acute inflammatory response compared to other irrigants under study, but subsided in 2 days. Its combination with EDTA also had similar inflammatory response as NaOCl alone, but of lower magnitude, suggesting NaOCl with EDTA as better root canal irrigant. MTAD caused necrosis of the skin tissue at 2 days and sloughing; thereafter, this study does not suggest its use as a root canal irrigant.

Background:Interaction between local anesthetic solution, lidocaine hydrochloride (with and without adrenaline), and root canal irrigants such as sodium hypochlorite (NaOCl), ethylene diamine tetra-acetic acid (EDTA), and chlorhexidine (CHX) has not been studied earlier. Hence, the purpose of this in vitro study was to evaluate the chemical interaction between 2% lidocaine hydrochloride (with and without adrenaline) and commonly used root canal irrigants, NaOCl, EDTA, and CHX.Materials and Methods:Samples were divided into eight experimental groups: Group I-Lidocaine hydrochloride (with adrenaline)/3% NaOCl, Group II-Lidocaine hydrochloride (with adrenaline)/17% EDTA, Group III- Lidocaine hydrochloride (with adrenaline)/2% CHX, Group IV-Lidocaine hydrochloride (without adrenaline)/3% NaOCl, Group V-Lidocaine hydrochloride (without adrenaline)/17% EDTA, Group VI-Lidocaine hydrochloride (without adrenaline)/2% CHX, and two control groups: Group VII-Lidocaine hydrochloride (with adrenaline)/deionized water and Group VIII-Lidocaine hydrochloride (without adrenaline)/deionized water. The respective solutions of various groups were mixed in equal proportions (1 ml each) and observed for precipitate formation. Chemical composition of the formed precipitate was then analysed by nuclear magnetic resonance spectroscopy (NMR) and confirmed with diazotation test.Results:In groups I and IV, a white precipitate was observed in all the samples on mixing the respective solutions, which showed a color change to reddish brown after 15 minutes. This precipitate was then analysed by NMR spectroscopy and was observed to be 2,6-xylidine, a reported toxic compound. The experimental groups II, III, V, and VI and control groups VII and VIII showed no precipitate formation in any of the respective samples, until 2 hours.Conclusion:Interaction between lidocaine hydrochloride (with and without adrenaline) and NaOCl showed precipitate formation containing 2,6-xylidine, a toxic compound.

Objective: The objective of this study was to observe the effect that 3% Sodium Hypochlorite and 17% Ethylenediamine Tetraacetic Acid (EDTA) with water in between, used sequentially and individually had in the disinfection of dentin blocks that were contaminated with Enterococcus faecalis. Materials and Methods: Thirty apical and coronal dentin block samples were divided into five groups (n=5): All samples were inoculated with Enterococcus faecalis Group 1: Samples were submerged in 3% NaOCl then in 17% EDTA. Group 2: Samples were submerged first in 17% EDTA and then in 3% NaOCl. Group 3: Samples were immersed in 3% NaOCl only. Group 4: Samples were submerged in 17% EDTA only. Group 5 (positive control group): Samples were only submerged in distilled water. All samples were submerged in distilled water after each irrigation cycle. The irrigation protocol was repeated in all groups until all dentin samples were exposed to 24ml of the irrigating solutions. CFU units were counted and classified in an ordinal scale and compared with the linear-by-linear association test. Results: A significant linear trend in the reduction of CFU was observed when NaOCl and EDTA were combined (independently of the sequence used) when compared to groups 3 and 4 where the irrigants were used individually both in coronal (p=9.45 x 10-21), and apical slices (p=2.33 x 10-20). NaOCl was significantly more effective than EDTA in both coronal and apical slices (p ≥ 0.000001) when used alone. Conclusion: 3% Sodium Hypochlorite was more effective than 17% EDTA. However, alternating 3% NaOCl with 17% EDTA resulted in better dentinal disinfection. Clinical Relevance: Establishing an irrigation protocol that is effective in eradicating bacteria entrenched in dentinal tubules can lead to a more successful outcome in endodontically treated teeth.

The conventional endodontic therapy primarily focuses on biomechanical preparation, which is achieved by the application of various intracanal irrigants and intracanal medicaments. One of the most commonly used intracanal irrigants - sodium hypochlorite (NaOCl) - has already been proven to have an antimicrobial effect as well as the ability to dissolve tissues in the areas where files cannot reach. One of the recently used irrigants having a promising effect is calcium hypochlorite (Ca(OCl)2), which has been shown to be relatively more stable than NaOCl and has much more chlorine ions. The aim of this study was to assess the individual cytotoxicity of various root canal irrigants and the combined cytotoxicity of NaOCl and Ca(OCl)2 with ethylenediaminetetraacetic acid (EDTA) against human gingival fibroblast (hGF) cells. The evaluation of the individual cytotoxicity was carried out with regard to the following root canal irrigants: NaOCl; Ca(OCl)2; and chlorhexidine (CHX). The evaluation of the combined cytotoxicity regarded NaOCl/EDTA and Ca(OCl)2/EDTA. The concentrations used were 0.025%, 0.050%, 0.10%, and 0.20%. The cytotoxicity against hGF cells was examined within a timeframe of 6 h and 24 h with the use of the sulforhodamine B (SRB) assay. It was observed that Ca(OCl)2 had a mean absorbance rate of 0.315 ±0.02, 0.294 ±0.03, 0.265 ±0.03, and 0.240 ±0.02 at 0.025%, 0.050%, 0.10%, and 0.20%, respectively. In combination with EDTA, the mean absorbance rate was 70.12 ±2.9, 67.42 ±4.3, 64.35 ±3.6, and 61.58 ±4.1 at 0.025%, 0.050%, 0.10%, and 0.20%, respectively. The cytotoxic effect of the root canal irrigants on hGF cells was observed to be statistically significant (p < 0.05). Calcium hypochlorite is less cytotoxic than NaOCl, and when used in combination with EDTA, it was shown to have its cytotoxic effect on hGF cells reduced to a great extent.

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.

This study aims to evaluate the bond strength of bioceramic root canal sealers, with different final irrigation protocols. A total of 104 human upper incisor teeth were selected for applying four different irrigation solutions (Ethylene diamine tetraacetic acid (EDTA), Chlorine Hexidine Gluconate (CHX), Sodium Hypochlorite (NaOCl), and Distilled Water (D.W)) and two root canal sealer protocols (Endosequence BC (BC), Well-Root ST (ST)), in this in vitro study. After root canal treatment specimens were sectioned to three parts (coronal, middle, and apical). Push-out bond strength test was performed in a universal testing machine (Zwick-Roel, Germany) at a crosshead speed of 1 mm/min. Regardless of the irrigation protocol and sealer used, the highest bond strength values were obtained from the apical section ($$p&lt;0.05$$). 5.25% NaOCl + 17% EDTA + 5.25% NaOCl and 2% CHX + 17% EDTA + D.W statistically showed the highest bond strength value and 2% CHX + 17% EDTA + 2% CHX group showed the lowest value in this study ($$p&lt;0.05$$). The bond strength values of Endosequence BC Sealer were statistically higher than the bond strength values of Well Root ST ($$p&lt;0.05$$). According to the final irrigation, Endosequence BC Sealer and Well Root ST root canal sealers showed the highest bonding strength in CHX + EDTA + D.W and NaOCl + EDTA + NaOCl groups.

The aim of this study was to evaluate and compare the apical microleakage of zinc oxide (ZOE) eugenol and Endoflas as obturating materials using different root canal irrigants in primary teeth. A total of 80 extracted primary anterior teeth were divided randomly into four groups with different irrigants and obturating materials used. Group I [ZOE + sodium hypochlorite (NaOCl)], group II [ZOE + NaOCI + ethylenediaminetetraacetic acid (EDTA)], group III (Endoflas FS + NaOCI), group IV (Endoflas FS + NaOCI + EDTA). Cleaning and shaping of the root canals were done using specified irrigants, followed by obturation with ZOE eugenol and Endoflas as per the respective groups. Specimens were then immersed in 2% methylene blue dye solution and stored for 24 hours. The specimens were split longitudinally into two halves and observed under a stereomicroscope. Apical microleakage was measured from the apex to the most coronal extent of dye penetration. The highest dye penetration was recorded for teeth filled with ZOE, group I (ZOE + NaOCl), with mean values of 1.924 ± 0.925. Endoflas group IV (Endoflas + NaOCI + EDTA) showed the lowest dye penetration with mean values of 0.901 ± 0.255. There was a statistically significant difference between the ZOE and Endoflas groups (p < 0.001). The result showed a statistically nonsignificant difference between the two Endoflas groups (p = 1.000). Minimum microleakage was found in group IV (Endoflas + NaOCI + EDTA). Endoflas FS exhibits less apical microleakage than ZOE eugenol as an obturating material in primary teeth. Hence, Endoflas could be a potential alternative to ZOE eugenol with better sealing ability as an obturating material in primary teeth. Also, the addition of EDTA to irrigation protocol has shown a statistically nonsignificant improvement in microleakage reduction with both obturating materials. Kale YJ, Misal S, Dadpe M, et al. Comparative Evaluation of Microleakage of Zinc Oxide Eugenol and Endoflas as Obturating Materials Using Different Root Canal Irrigants in Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(11):1252-1257.

Purpose: analytical analysis and study of literature sources comparing irrigation solutions and their activation methods in routine endodontics.Materials and methods: in the eLibrary database, PubMed, Google Scholar and Meduniver requested scientific articles using the keywords: root canal cleaning, sodium hypochlorite, chlorhexidine, ethylenediaminetetraacetic acid, root canal irrigation, activation of irrigation solutions. Thus, this article included 35 research papers on the topic of irrigation solutions and their activation.Results: this analytical analysis and the study of literary sources have shown that one of the most important factors in the prevention and treatment of endodontic pathology is adequate cleaning and irrigation of the root canal, since in the vast majority of cases they have an irregular shape, numerous lateral, deltoid branches and anastomoses. Oval, dumbbell-shaped or C-shaped root canals are also quite common. In modern endodontics, dentists use sodium hypochlorite, ethylenediaminetetraacetic acid and chlorhexidine as irrigants on a daily basis.Conclusion: based on the literature, it was revealed that one of the best disinfectant solutions for root canals today is sodium hypochlorite, however, it does not meet all the parameters of an ideal irrigant.

Ex vivo detection and quantification of apically extruded volatile compounds and disinfection by-products by SIFT-MS, during chemomechanical preparation of infected root canals

Hundreds of bacterial species inhabit the mouth, because of bacterial interactions, nutrient availability and low oxygen potentials in root canals with necrotic pulp, the number of bacterial species present in endodontic infections are restricted. These selective conditions lead to the predominance of facultive and strictly anaerobic microorganisms that survive and multiply, causing infections that stimulate local bone resorption, and are more resistant to endodontic treatment. Instrumentation of the root canal alone is not sufficient to remove infected necrotic tissues. The root canal must never be instrumented dry, an irrigating solution is always needed to reduce the amount of friction between the instrument and dentin surface to prevent binding and sticking. An irrigating solution is also needed to improve the cutting effectiveness of the files and instruments, dissolve tissue, cool the file and tooth, wash debris from the root canal, and be bactericidal in areas of the canal which could not be instrumented. Sodium hypochlorite has been the most widely used root canal irrigating solution for several decades, because it is inexpensive, can quickly dissolve infected necrotic tissues and is bactericidal. Sodium hypochlorite is very toxic to tissues when undiluted and so accidental spillage is always a concern among dentists. A severe limitation of Sodium hypochlorite and most other irrigating solutions is that they are unable to dissolve the instrumentation debris on cut dentin surfaces, called smear layer. The smear layer is a 1 to 5 micron thick layer of cut debris created on the surface of instrumented dentin, composed of dentin, odontoblastic processes, non-specific inorganic contaminants and microorganisms. To remove smear layer a chelating agent must be used after the irrigating solution to help clean the instrumented root canal surfaces. The most widely used chelating agent inside the root canal is 17% ethylenediaminetetraacetic acid (EDTA). A solution of 17% EDTA is a very reliable endodontic chelating agent when used fresh and at room temperature, but its chelating effects are time sensitive. Testing and clinical evidence has shown that 17% EDTA needs to be placed inside the root canal for 1 minute to effectively dissolve organic components and smear layer. The EDTA then needs to be suctioned, dried with paper points, and/or rinsed with Sodium hypochlorite to ensure it has been completely removed from the root canal after use. The process of canal preparation with files, instruments, and irrigating solutions is usually sufficient to remove most of the necrotic and infected tissues. Some recent articles suggest that the ultrasonic activation of irrigating solutions by using a high-speed vacuum; the EndoVac system, and that a laser using photon-induced photoacoustic streaming (PIPS) can improve the debridement of root canals.