Effect of Endodontic Irrigating Solutions on Radicular Dentine Structure and Matrix Metalloproteinases-A Comprehensive Review.

Irrigating solutions play an important role in the eradication of intracanal microbes and debris dissolution during endodontic treatment. Different combinations of solutions and protocols have been advocated, with sodium hypochlorite (NaOCl), ethylenediamine tetra acetic acid (EDTA), and chlorhexidine (CHX) remaining the most widely used ones by many clinicians. Although these solutions provide efficient inorganic dissolution and antimicrobial capacity, their use has also been reported to cause undesired effects on root dentin composition and mechanical and biomechanical properties, such as microhardness, surface roughness, bond strength, and matrix metalloproteinase (MMP) activity. Several corroborating studies attribute these changes in mechanical properties of dentine to the use of irrigating solutions, and there are limited reports on how the solutions affect the expression of MMPs, which may be a correlating link to understanding the role of these enzymes in dentin collagen and changes in the mechanical properties of dentin. Hence, using the basis of several studies from the literature, the objective is to comprehensively review the influence of individual and combined irrigating solutions on root dentine structure and the activity of the MMPs.

In Situ Zymography Analysis of Matrix Metalloproteinases Activity Following Endodontic Irrigation Protocols and Correlation to Root Dentine Bond Strength.

The objective was to evaluate the effect of different root canal irrigating solutions on the activity of matrix metalloproteinases (MMPs), and correlation to the push-out bond strength (PBS) and nanoleakage expression (NL) in the root dentin. Seventy-two single-rooted teeth were treated endodontically and distributed into four groups (n = 6 for in-situ zymography, n = 10 for PBS, and n = 2 for NL per group) according to the irrigating solutions used: (I) saline (S); (II) 5.25% sodium hypochlorite (SH); (III) 5.25% SH + 10% citric acid (CA); and (IV) 5.25% SH + 10% CA + 0.2% chlorhexidine (CHX). After root canal obturation, post space was prepared to receive the glass fiber post. Dual-cure resin was used for luting and light polymerization was performed. The root/fiber post assemblies were sectioned and subjected to in situ zymography, and PBS and NL expression analysis tests. The enzymatic activity was quantified and expressed as a percentage of the green fluorescence, while fractographic evaluation was performed after PBS with a stereomicroscope, and data were statistically analyzed at p < 0.05. The zymography analysis shows high expression of MMPs in the middle third of the root in all groups, while the most abundant activity of MMPs following the irrigating solutions is observed in groups I and III, where saline and citric acid are used, respectively. Inversely, group IV, where chlorhexidine is the final rinse, records the lowest MMP activity with the highest PBS, and the statistical analysis of the groups are ranked as: IV > II > III > I (p < 0.05). The combination of SH, CA, and CHX results in lower expression of MMPs and higher push-out bond strength of fiber posts to root dentin, with no difference seen in the nanoleakage expression (p > 0.05); hence, this irrigation regime with chlorhexidine as a final rinse is more favorable than other combinations in ensuring optimal adhesion to root dentine.

Corrigendum: Irrigating Solutions and Activation Methods Used in Clinical Endodontics: A Systematic Review.

[This corrects the article DOI: 10.3389/froh.2022.838043.].

Efficacy of Povidone Iodine Against Microbial Biofilms in Breast Implants With Different Textures: Results From an in vitro Study.

Background: In the practice of breast augmentation and reconstruction, implant irrigation with various solutions has been widely used to prevent infection and capsular contracture, but to date, there is no consensus on the optimal protocol to use. Recently, application of povidone iodine (PI) for 30 min has shown in vitro to be the most effective irrigating formula in reducing contamination in smooth breast implants. However, as 30 min is not feasible intraoperatively, it is necessary to determine whether shorter times could be equally effective as well as to test it in both smooth and textured implants. Methods: We tested the efficacy of 10% PI at 1', 3', and 5' against biofilms of 8 strains (2 ATCC and 6 clinical) of Staphylococcus spp. on silicone disks obtained from Mentor® and Polytech® implants of different textures. We analyzed the percentage reduction of cfu counts, cell viability and bacterial density between treatment (PI) and control (sterile saline, SS) groups for each time of application. We consider clinical significance when > 25% reduction was observed in cell viability or bacterial density. Results: All textured implants treated with PI at any of the 3 exposure times reduced 100% bacterial load by culture. However, none of the implants reached enough clinical significance in percentage reduction of living cells. Regarding bacterial density, only 25-50 µm Polytxt® Polytech® implants showed significant reduction at the three PI exposure times. Conclusion: PI is able to inhibit bacterial growth applied on the surface of breast implants regardless of the exposure time. However, no significant reduction on living cells or bacterial density was observed. This lack of correlation may be caused by differences in texture that directly affect PI absorption.

Irrigating Solutions and Activation Methods Used in Clinical Endodontics: A Systematic Review.

BACKGROUND: Ex vivo and in vitro studies have demonstrated the effectiveness of some irrigation protocols in reducing the bacterial load in the root canal system. However, standardized protocols have not yet been defined for the real clinical context due to many irrigation procedures available. OBJECTIVE: To evaluate the clinical endodontic protocols and limitations of irrigating solutions in the disinfection of the root canal system in patients with apical periodontitis. METHODS: PubMed, Scopus, Embase, Web of Science, and Cochrane databases were searched for randomized controlled trials (RCT) published until January 2021. Hand searching was also performed. Studies focused on evaluating the effectiveness of irrigating solutions and/or irrigation activation methods in reducing the bacterial load in the root canal system were considered. The Cochrane risk-of-bias tool for randomized trials (RoB2) was used to assess the quality of the studies. RESULTS: Four hundred and twenty eight published articles were identified. After removing the duplicate studies and analyzing full texts, seven RCTs were selected. Two studies compared pure NaOCl with some combination of NaOCl with HEDP and MTAD. Two studies analyzed the antibacterial efficacy of NaOCl and chlorhexidine (CHX). Three studies compared conventional needle irrigation with different irrigation activation methods (PUI, XP-endo finisher, F-file activator, EndoVac activator). The review attained a satisfactory methodology. The main results of each included study were described. DISCUSSION: Activation methods provide significantly higher biofilm reduction than conventional needle irrigation methods. Combinations of NaOCl with different chelating agents were ineffective in terms of antimicrobial, but it could potentially increase the risk of irrigant extrusion. However, the irrigating protocols were not carefully detailed, especially those regarding the irrigants application time or total volume. The existing literature lacks high-quality studies. The level of evidence is moderate. CONCLUSIONS: The available data is too heterogeneous to compare and identify the superiority of specific valuable irrigation protocols in each clinical context. Application time, volume, and activation methods should be standardized to determine the optimal irrigating procedures to reduce the bacterial load and ensure higher predictability of the endodontic treatment. SYSTEMATIC REVIEW REGISTRATION: (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=218555), PROSPERO registration: CRD42020218555.

Efficiency of an Integrated Apex Locator in Determining Working Length in Various Irrigating Solutions: An In Vivo Study.

OBJECTIVES: The objective of this in vivo study was to compare and evaluate the accuracy of VDW Gold (VDW, Munich, Germany) integrated apex locator (IAL) and Root ZX Mini (J. Morita Corp., Kyoto, Japan) in two different irrigating solutions. MATERIALS AND METHODS: Forty patients who required extraction were included in the study. Following local anesthesia, access opening was performed under rubber dam isolation. Initial negotiation of canal was performed using size 10 K-Files (M-Access, Dentsply Maillefer, Ballaigues, Switzerland). Cervical preparation was carried out using Rotary ProTaper SX files (Dentsply Maillefer, Ballaigues, Switzerland) under copious irrigation with 3% sodium hypochlorite. Patients were divided into two groups of 20 each: Group I (NaOCl) and Group II (CHX). The working length (WL) was determined in triplicates for each tooth using Root ZX apex locator and with S1 ProTaper rotary file in continuous motion in case of VDW Gold IAL in the presence of 3% sodium hypochlorite and 2% chlorhexidine. Therapeutic extraction was performed and WL was determined using size 15 K-Files under 20× magnification. RESULTS: The paired sample independent t test showed that there was no significant difference between the Root ZX and VDW apex locator in determining the minor foramen in NaOCl group (P = 0.234, 0.453 respectively) and CHX group (P = 0.085, 0.087) when compared with actual working length. CONCLUSION: Both the apex locators were equally effective in determining WL at 0.5 mm from the apex in presence of irrigating solutions, that is, NaOCl and chlorhexidine.

Cytotoxic effects of alkaline tetrasodium EDTA irrigating solutions.

The aim of this study is to determine the cytotoxic effects of tetrasodium ethylenediaminetetraacetic acid (EDTANa4) when used alone or when combined with sodium hypochlorite (NaOCl), with and without the addition of cetrimide (CTR). Human pulmonary fibroblast cell line was exposed to the following irrigating solutions: group 1, 2.5% NaOCl; group 2, 10% EDTANa4; group 3, 20% EDTANa4; group 4, 2.5% NaOCl/5% EDTANa4; group 5, 2.5% NaOCl/10% EDTANa4; group 6, 2.5% NaOCl/5% EDTANa4/0.2% CTR; group 7, 2.5% NaOCl/10% EDTANa4/0.2% CTR; group 8, control, cells in Dulbecco's modified Eagle's medium. Methyl thiazol tetrazolium assay was used to determine the viability of cells after 1 and 24 h. Viability percentages were analyzed for global comparison using the Welch test followed by the Games-Howell test to determine groups with similar viability, and the Student's t test was used to compare the two times. The lowest viability was obtained with a 2.5% NaOCl solution at both time periods. The association of NaOCl with EDTANa4 increased the cellular viability in direct relation with the concentration of the chelating agent. Globally, after 24 h of exposure, cell viability reduced. The solutions of EDTANa4 showed moderate cytotoxic effects when compared with NaOCl alone.

Evaluation of the efficacy of a novel antibiotic-steroid paste versus conventionally used intracanal antibiotic pastes and irrigating solutions against a 3-week-old biofilm of Enterococcus faecalis.

INTRODUCTION: Intracanal medicaments have been used during endodontic regenerative procedures to eradicate endodontic pathogens. AIMS: The aim of our study was (1) to evaluate the antimicrobial efficacy of a novel antibiotic-steroid paste over the regularly used calcium hydroxide (Ca (OH)2), double antibiotic paste (DAP), and modified triple antibiotic paste (M-TAP) and (2) to check the antimicrobial efficacy of irrigating solutions, Chlorhexidine (CHX), and sodium hypochlorite (NaOCl) against a 3-week-old Enterococcus faecalis (E. faecalis) biofilm. MATERIALS AND METHODS: A total of 112 human extracted teeth were contaminated with E. faecalis for a period of 21 days. A novel antibiotic-steroid paste, Ca (OH) 2, DAP, M-TAP, and a placebo were placed inside the canal, sealed, and incubated in an aerobic environment at 37°C. For irrigating solutions, each prepared sample was immersed in 1 ml of sterile saline for 1 min, followed by irrigating and immersion with 1.5% NaOCl and 2% CHX for 5 min. An antimicrobial assessment was performed at the end of 2 days and 7 days, with seven teeth from each group, for each time interval. Dentin debris collected was transferred to the respective medium for culture. After 24 h, colonies were counted using classical bacterial counting technique as colony-forming units. RESULTS: Statistical analysis revealed that the novel antibiotic-steroid paste showed a statistically insignificant difference when compared to DAP, which had the highest antimicrobial properties. CONCLUSION: This novel functional paste has antimicrobial efficacy comparable with that of DAP.

Electrochemical Disinfection of Experimentally Infected Teeth by Boron-Doped Diamond Electrode Treatment.

Disinfection and prevention of re-infection are the decisive treatment steps in endodontic therapy. In this study, boron-doped diamond (BDD) electrodes have been fabricated and used for disinfecting the root canals of extracted human teeth, which had been covered with bacterial biofilms formed by Bacillus subtilis and Staphylococcus epidermidis. The growth of B. subtilis could be successfully impaired, achieving a complete disinfection after 8.5 min treatment time with the success of disinfection depending on the insertion depth of the electrode in the root canal. S. epidermidis could completely be removed after 3.5 min treatment time. A clinically applicable electrode array led to complete disinfection after treatment times of 10 min for S. epidermidis and 25 min for B. subtilis. BDD electrode application allowed for the improved disinfection of root canals and dentin tubules based on a continuous production of reactive oxygen species and their enhanced penetration of dentin tubules most likely due the formation of a continuous stream of small gas bubbles. The treatment times that are required here will be shortened in clinical application, as mechanical shaping of the canal system would precede the disinfection process.

Postoperative Quality of Life Following Conventional Endodontic Intracanal Irrigation Compared with Laser-Activated Irrigation: A Randomized Clinical Study.

Objective: The aim of this randomized clinical study was to evaluate the effect of laser-activated irrigation using a photon-induced photoacoustic streaming (PIPS) technique on postoperative pain following completion of root canal obturation. Methods: Fifty-six patients were enrolled in this randomized clinical trial. Fifty-six healthy premolars or molars with asymptomatic irreversible pulpitis, symptomatic irreversible pulpitis, or symptomatic pulpal necrosis, with or without apical periodontitis, were mechanically prepared for endodontic treatment and divided into two groups. Patients were randomly allocated to treatment groups. In the positive control group G1, the final irrigation with 2 cc of 5.25% sodium hypochlorite (NaOCl) was achieved using a 27G needle, introduced into the canal to a distance of 5 mm from the predetermined working length. In the experimental group G2, the root canals were irrigated with 17% ethyldiamine tetric acid (EDTA) and 5.25% NaOCl following the PIPS protocol, using an Er:YAG 2940 nm laser (LightWalker ATS®; Fotona, Slovenia) with a 600 µm diameter tip and operating parameters of 20 mJ per pulse, 15 Hz frequency, 0.3 W average power, and a 50-µs pulse duration. Postoperatively, the patients were advised to take a minor analgesic (ibuprofen 400 mg) in the event of pain perception. Postoperative pain levels were assessed after 24, 48, and 72 h and 7 days through the use of a Visual Analogue Scale questionnaire, completed by each patient. Data were analyzed using Kolmogorov-Smirnov, Fisher Exact, Chi square, Mann-Whitney test, and Friedman's test. The level of significance was set at α = 0.05. Results: There was no significant difference between the laser-irradiated group and the control group (p < 0.5). Laser activation of irrigating solutions did not increase postoperative pain. Conclusions: The outcome of this investigation indicated that PIPS was as effective as conventional irrigation in relation to postoperative pain, making this activation technique interesting to use for supplementary root canal disinfection.

Effect of Different Irrigation Solutions on the Apical Sealing Ability of Different Single-cone Obturation Systems: An In Vitro Study.

AIM: The aim of this study was to assess the effect of three root canal irrigants on the apical sealing ability of three single-cone obturation systems. MATERIALS AND METHODS: One hundred maxillary central incisors were selected and their crowns were cut. The roots were divided into three experimental groups of 30 samples each, and one control group of 10 samples (5 positives and 5 negatives). Each experimental group was divided equally into three subgroups according to the obturation system. All root canals were instrumented using ProTaper Universal rotary system and irrigated with 3% sodium hypochlorite (Group 1), 2% chlorohexidine (Group 2), 3% hydrogen peroxide (Group 3). Finally, root canals were irrigated with 17% EDTA followed by distilled water, then obturated with a single-cone technique using gutta-percha/MTA Fillapex (Subgroup A), gutta-percha/ AH Plus (Subgroup B), and Resilon/Relseal SE (Subgroup C). The microleakage was assessed using linear dye penetration method and data were statistically analyzed. RESULTS: Significant differences were found between all groups and subgroups (p < 0.005). When 3% of hydrogen peroxide was used, no leakage was observed with AH Plus sealer, and a high amount of leakage (5.82 ± 0.47 mm) was observed with Realseal SE. MTA Fillapex (0.49 ± 0.08 mm) and Realseal SE (1.11 ± 0.50 mm) showed the lowest amounts of leakage when 2% chlorohexidine and 3% sodium hypochlorite were used, respectively. CONCLUSION: The type of irrigating solution and obturation system could affect the apical leakage value when single-cone obturation technique was used. AH Plus/gutta-percha obturation system showed no apical leakage when root canals were irrigated with 3% hydrogen peroxide. The using of 2% chlorohexidine improved sealing ability of MTA Fillapex/gutta-percha. The apical sealing ability of Realseal SE/Resilon decreased when 3% hydrogen peroxide or 2% chlorhexidine was used. CLINICAL SIGNIFICANCE: Proper selection of irrigating solutions may positively influence the apical sealing ability of single-cone obturation systems.

Intracanal heating of sodium hypochlorite: Scanning electron microscope evaluation of root canal walls.

INTRODUCTION: The aim of this study is to evaluate the surface of root canals dentine using scanning electron microscope (SEM) after instrumentation with rotary Nickel-Titanium systems and two different protocols of activation of sodium hypochlorite (NaOCl) (extracanal heating at 50°C and intracanal heating at 180°C), to assess the presence/absence of smear layer and also the presence/absence of open dentinal tubules along the walls at the coronal, middle, and apical third of each sample. MATERIALS AND METHODS: Thirty-six single-rooted teeth were selected, divided into three groups and shaped with ProTaper Universal instruments following irrigation protocols with 5.25% NaOCl. At the end of the preparation, three different protocols of activation were used: nonheated NaOCl in Group A, extra-canal heated NaOCl at 50°C for Group B and intracanal heated NaOCl at 180°C for Group C. Specimens were cut longitudinally and analyzed by SEM at standard magnification of ×1000. The presence/absence of the smear layer as well as the presence/absence of open tubules at the coronal, middle, and apical third of each canal were estimated using a five-step scale for scores. Numeric data were analyzed using Kruskal-Wallis and Mann-Whitney U statistical tests and significance was predetermined at P < 0.05. RESULTS: Kruskal-Wallis analysis of variance (ANOVA) for debris score showed significant differences among the Ni-Ti systems (P < 0.05). Mann-Whitney test confirmed that Group A presented significantly higher score values than other Ni-Ti systems. The same results were assessed considering the smear layer scores. ANOVA confirmed that the apical third of the canal maintained a higher quantity of debris and smear layer after preparation of all the samples. DISCUSSION AND CONCLUSIONS: Intra-canal heating of NaOCl at 180°C proved to be more effective in obtaining clean canal walls. On the other hand, extra-canal heating at 50°C of NaOCl left a higher quantity of debris and the smear layer was widely represented.

Antimicrobial efficacy of 980 nm diode laser on Enterococcus feacalis in conjunction with various irrigation regimes in infected root canals: An in vitro study.

AIM: The aim of the present study was to evaluate and compare the antimicrobial efficiency of different irrigating solutions against Enterococcus faecalis with or without the use of 980 nm diode laser in infected root canals. MATERIALS AND METHODS: A total of 100 freshly extracted human single-rooted teeth were divided into three experimental groups (n = 30) and one control group (n = 10). Experimental group was subdivided into two subgroups A and B (n = 15), whereas control group was subdivided into positive and negative controls (n = 5). After access cavity preparation, the root canals were prepared using ProTaper rotary instruments. A volume of 5 ml of 5.25% sodium hypochlorite and 17% Ethylenediaminetetraacetic acid, 1.2 ml of 2% chlorhexidine gluconate, and 2 ml of neem solution was used for irrigation in Group I, II, and III, respectively. E. faecalis (ATCC 29212) was inoculated into each canal of experimental groups and incubated for 2 weeks under aerobic conditions at 37°C. In all the subgroups B, laser irradiation was performed, whereas, in subgroup A, no laser irradiation was done. In negative control, E. faecalis was not inoculated in samples, but in positive control, E. faecalis inoculation and incubation procedure was followed. With circumferential filing using #40 reamer, dentinal chips were collected using sterile paper points, vortexed in sterile saline, was then applied to UTI Hicrome agar culture plates and incubated at 37°C for 48 h. The cfu/ml for each plate was calculated using a bacterial colony counter. The data obtained were subjected to statistical analysis using SPSS software version 20.0. RESULTS: The study showed that the least number of bacterial cfu/ml was observed in Group IB. The order of bacterial colony count (cfu/ml) was observed as Group IB

Comparative Clinical and Microbial Evaluation of Two Endodontic File Systems and Irrigating Solutions in Pediatric Patients.

AIMS: The purpose of the study was to determine the best combination for chemomechanical preparation in primary teeth using two endo file systems (hand and rotary) along with two different irrigants. MATERIALS AND METHODS: Sixty primary molars indicated for pulpectomy, underwent chemomechanical preparation using endo files (H hand files and rotary Protaper files) and root canal irrigating solutions (Smearclear and QMiX). Samples from root canals were collected before and after the chemomechanical preparation of the canal and were cultured for microbial analysis of Enterococcus faecalis. RESULTS: Endodontic irrigating solutions showed significant differences of effectiveness on the growth inhibition of bacterial strain. The present study confirmed that the in vivo antimicrobial efficacy of QMiX solution was statistically significant when compared to the Smearclear solution. CONCLUSION: Based on the antimicrobial efficacy observed in the present study, it may be concluded that QMiX has a great potential than Smearclear as an intracanal irrigation solution in primary teeth and rotary preparation may be considered as more efficient and time-saving mechanical preparatory technique in primary molars.

Decalcifying capability of irrigating solutions on root canal dentin mineral content.

BACKGROUND: Chelating agents are believed to aid root canal irrigation and to be able to remove the inorganic smear layer. AIMS: The purpose of the present study was to evaluate and to compare the decalcifying capability of different irrigating solutions (Tubuliclean, Largal Ultra, ethylenediaminetetraacetic acid 17%, Tetraclean, Tetraclean NA). MATERIALS AND METHODS: Sixty maxillary central incisors were used. Root canals were instrumented and irrigated. From each root, four comparable slices of cervical dentin were obtained. At three successive 5-min interval immersion times, the concentration of calcium extracted from root canal dentin was assessed with an inductively coupled plasma-atomic emission spectrometer. STATISTICAL ANALYSIS USED: Data were analyzed by means of Kruskal Wallis and Mann-Whitney tests. Significance was predetermined at P < 0.05. RESULTS AND CONCLUSIONS: For all irrigating solutions, the maximum amount of Ca(2+) extracted from root canal dentin samples was reached after 10 min contact time except for citric acid-based agents (Tetraclean and Tetraclean NA) which induced a higher and still increasing calcium release even after 10 min contact time. In order to obtain an efficient decalcifying action on dentin and to facilitate the biomechanical procedures, citric acid-based irrigants can be applied.

Avaliação da efetividade de diferentes protocolos de irrigação na limpeza do canal radicular / Evaluation of the effectiveness of different irrigation protocols in the root canal cleaning

O objetivo desse estudo foi avaliar a capacidade de dissolução e remoção de biofilme formado in situ, na remoção de smear layer e debris empregando dez protocolos de irrigação final (solução fisiológica com ou sem agitação ultrassônica; ou hipoclorito de sódio como irrigante primário, seguido de solução salina, ou EDTA 17%, ou ácido peracético (PAA) 2%, ou Qmix, com ou sem agitação ultrassônica de ambas as soluções). Duzentos e trinta raízes bovinas foram seccionadas e cortadas com 15mm de comprimento e instrumentadas com o instrumento Reciproc R50. Para a análise da remoção de debris e smear layer foram separadas 100 raízes, que foram clivadas e, no terço apical de uma das metades radiculares, foi confeccionado um sulco longitudinal, simulando extensões de canais ovais, posteriormente preenchidos com detritos artificiais. Após esse procedimento na outra metade foi realizada a formação de smear layer com uma vigora instrumentação da parede com movimentos de limagem. Essas amostras foram levadas ao MEV para análise prévia. Essas metades, depois de justapostas, voltaram a mufla e foram realizados os protocolos de tratamento. A análise dos dados foi realizada por meio de scores. Para a análise da dissolução e viabilidade do biofilme in situ 130 raízes foram separadas preparadas com instrumento R25 e um disco de dentina foi retirado do terço médio com uma trefina. Esses discos foram inseridos em uma placa de hawley, que foi utilizada pelo pesquisador durante três dias. Os discos foram removidos e deixados por 48 horas em BHI, em estufa a 37oC. Após a contaminação os discos voltaram para a raiz de onde foram removidos e fixados com cera utilidade voltando a mufla, sendo tratados e avaliados. Setenta discos foram utilizados para análise da dissolução e viabilidade em confocal e as imagens obtidas foram avaliadas pelo software Bioimage. Sessenta discos foram utilizados para a análise da dissolução do biofilme em MEV, sendo avaliados pré e pós-tratamento...

The aim of this study was to evaluate the dissolution capacity and removal of biofilm formed in situ, in smear layer and debris removal and debris use ten final irrigation protocols (saline with or without ultrasonic agitation, or sodium hypochlorite as primary irrigating, and then used saline or 17% EDTA, or 2% peracetic acid (PAA), or Qmix, with or without ultrasonic agitation of both solutions). Two hundred and thirty bovine roots were sectioned and cut with 15mm in length and instrumented with Reciproc R50. For the analysis of removal of debris and smear layer were separated 100 roots, which were cleaved, and the apical third of the half of root, has a longitudinal groove made simulating extensions of oval canals, artificial subsequently filled with debris. After this procedure was performed on half the formation of smear layer with a force wall with instrumentation filing motions. These samples were taken to SEM prior to analysis. These halves, after juxtaposed, and again the flask were held treatment protocols. Data analysis was performed by means of scores. For the analysis of the dissolution and viability of the biofilm in situ roots 130 were prepared with R25 separate instrument and dentin disc was taken from the middle third with a trephine. These disks were inserted into a hawley plate, which was used by the researcher for three days. The discs were removed and left for 48 hours in BHI at 37oC. After contamination disks back to the root from which they were removed and fixed with wax utility returning to muffle being treated and evaluated. Seventy disks were used for analysis of dissolution and viability and confocal images were evaluated by Bioimage software. Sixty discs were used for the analysis of the dissolution of the biofilm SEM and are assessed before and after treatment. Comparing the groups for the removal of smear layer statistically significant differences were found (P <0.05) between the protocols used EDTA and Qmix with the...

Changes in pH of irrigating solutions after contact with human root dentin / Variaciones del ph de soluciones de irrigación endodónticas en contacto con dentina radicular humana

El objetivo de este trabajo fue estudiar in vitro el comportamiento del pH de diferentes soluciones de irrigación endodónticas, usadas solas o en forma consecutiva, después del contacto con dientes humanos extraídos. Se seleccionaron premolares inferiores. El tercio medio radicular se dividió en 6 partes. Los especímenes obtenidos se dividieron en 6 grupos,de acuerdo a la solución de irrigación empleada: 1) agua destilada; 2) NaClO 1 por ciento; 3) Ácido Cítrico 1 por ciento (AC); 4) EDTA 17 por ciento; 5) AC 1 por ciento + NaClO 1 por ciento ; 6) EDTA 17 por ciento + NaClO 1 por ciento. Los especímenes fueron sumergidos en 1 mL de cada solucióna 37°C. Aquellos del grupo 1, 2 y 3 durante 5 minutos, y el resto, consecutivamente 2,5 minutos. Se determinaron pH inicial y final para cada solución. Los datos fueron analizados utilizando Test T, ANOVA y Test de comparaciones múltiples de Tukey. A los 2,5 y 5 minutos de exposición hubo diferencias estadísticamente significativas entre el pH inicial y final en todas las soluciones. El pH disminuyó en el caso de agua destilada e NaClO, mientras que aumentó en AC y EDTA. In vitro, el pH de todas las soluciones se modificó después del contacto con dentina radicular humana en ambos períodos de tiempo (2,5 y 5 minutos).

The aim of this study was to analyze the in vitro behavior of the pH of different irrigating solutions, used alone or consecutively, after contact with extracted human teeth. Mandibular human premolars were selected. The middle thirds were divided into 6 parts. The specimens obtained were divided into 6 groups and treated with irrigating solutions: 1) distilled water; 2) 1% NaOCl; 3) 1% Citric Acid (CA); 4) 17% EDTA; 5) 1% CA + 1% NaOCl; 6) 17% EDTA + 1% NaOCl. Specimens were immersed in 1 mL of each solution at 37ºC, those of groups 1, 2, 3 and 4, for 5 minutes, and the rest, consecutively for 2.5 minutes in each solution. Initial and final pH of the solutions were determined. Data were analyzed by the T Test, one-way analysis of variance (ANOVA) and Tukey multiple comparison Test. At 2.5 and 5 minutes there were significant differences between the initial and final pH for all solutions. The pH values decreased for distilled water and NaOCl, while they increased for CA and EDTA. In vitro, the pH of all solutions was modified after contact with root dentin at both test times (2.5 and 5 min).

Comparative Evaluation of the Effect of EDTA, EDTAC, NaOCl and MTAD on Microhardness of Human Dentin - An In-vitro Study.

AIM: The aim of this study was to evaluate the microhardness of human dentin by using four irrigating solutions. Materials and Methodos: A total of 40 extracted mandibular premolars were selected and sectioned horizontally in the middle third of the root. Forty specimens of 4 mm thickness were embedded in acrylic resin and polished. Four test groups, each group containing ten specimens were immersed in respective irrigating solution and subjected to vicker's microhardness test at T0, T2 and T5min. STATISTICAL ANALYSIS: The data obtained were analyzed using the one way ANOVA followed by Tukey HSD method with ap=0.05 as the level for statistical significance. RESULTS: Suggested that there was no statistically significant difference in mean values between four experimental irrigating solutions. CONCLUSION: Mixture of Tetracycline isomer i.e. Doxycycline, Citric acid and a Detergent (Tween 80) MTAD not altered the microhardness of root canal dentin significantly and seems to be an appropriate irrigating solution, because of its harmless effect on the microhardness of the root canal dentin.

Avaliação histoquímica da permeabilidade dentinária após a utilização do edta como auxiliar na irrigação do canal radicular / Histochemical evaluation of dentin permeability after using edta as auxiliar irrigation of the root canal

O presente estudo avaliou a permeabilidade dentinária em toda a extensão do canal radicular após o uso do EDTA associado a diferentes concentrações de NaOCl. Foram utilizados cinquenta incisivos bovinos divididos em cinco grupos experimentais (n=10) de acordo com as soluções irrigantes empregadas: G1- NaOCl 1%; G2- NaOCl 5,25%; G3- NaOCl 1% + EDTA; G4- NaOCl 5,25% + EDTA; G5- Água destilada (grupo controle). Após o preparo biomecânico, as raízes foram submetidas ao método de coloração histoquímico com sulfato de cobre a 10% e ácido rubeânico a 1% para identificação da permeabilidade dentinária. Para a análise morfométrica as amostras foram seccionadas transversalmente, obtidas três secções de cada terço, desidratadas e clarificadas. Analisadas em microscopia óptica para quantificar a penetração dos íons cobre na dentina radicular. Após a análise estatística dos dados, os resultados indicaram que, houve diferença significativa entre os terços analisados seguindo uma ordem de efetividade do terço cervical maior que o médio e este maior que o apical. Entretanto, nenhuma diferença significante em relação à permeabilidade foi encontrada quando se comparou as diferentes soluções estudadas. Concluiu-se que o uso do EDTA associado com diferentes concentrações de hipoclorito de sódio, como irrigante final, não promoveu alteração na permeabilidade dentinária no canal radicular em relação as soluções usadas isoladamente.

This study evaluated the dentine permeability on the length of the root canal after the use of EDTA associated with different concentrations of NaOCl. Fifty bovine incisors were used divided into five experimental groups (n = 10) according to the irrigating solutions used: G1- 1% NaOCl; G2- 5.25% NaOCl; G3- 1% NaOCl + EDTA; G4- 5.25% NaOCl + EDTA; G5- distilled water (control group). After biomechanical preparation, the roots were subjected to histochemical staining method with 10% copper sulfate and then in 1% rubeanic acid alcohol solution for identification of dentin permeability. For the morphometric analysis the samples were cross sectioned, obtained three sections of each third, dehydrated and clarified. Analyzed with light microscopy to quantify the penetration of copper ions in the root dentin. After statistical analysis, the results indicated that there were significant differences among thirds analyzed by an order of effectiveness of the cervical third larger than the middle and this larger than the apical. However, no significant difference in relation to the permeability was found when comparing the different solutions studied. In conclusion, the use of EDTA associated with different concentrations of sodium hypochlorite, as final rinse, did not cause changes in dentin permeability in relation solutions used alone.

Effect of sodium hypochlorite and edta irrigation, individually and in alternation, on dentin microhardness at the furcation area of mandibular molars

The aim of this study was to evaluate the effect of irrigation regimens on dentin microhardness at the furcation area of mandibular molars, using sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA), individually and in alternation. The occlusal surface and the roots of 20 non-carious extracted human permanent mandibular molars were cut transversally and discarded. The tooth blocks were embedded in acrylic resin and randomly assigned to 4 groups (n=5) according to the irrigating regimens: 1% NaOCl solution, 17% EDTA solution, 1% NaOCl and 17% EDTA and distilled water (control). Knoop microhardness of dentin at the furcation area was evaluated. Data were analyzed using one-way ANOVA and Tukey's multiple comparison tests (α=0.05). The results of this study indicated that all irrigation solutions, except for distilled water (control), decreased dentin microhardness. EDTA did not show a significant difference with NaOCl/EDTA (p>0.05), but showed a significant difference with NaOCl (p<0.01). EDTA and NaOCl/EDTA showed a maximum decrease in microhardness. The 17% EDTA solution, either alone or in combination with 1% NaOCl reduced significantly dentin microhardness at the furcation area of mandibular molars.

A proposta desse estudo foi avaliar o efeito do NaOCl 1% e do ácido etilenodiaminotetracético 17% (EDTA), de forma isolada e alternada, sobre a microdureza dentinária da região da furca de molares inferiores. A superfície oclusal e as raízes de vinte molares inferiores, recém extraídos, foram cortadas transversalmente e descartadas. Os espécimes foram distribuídos em 4 grupos (n=5) de acordo com a solução irrigante utilizada. As soluções empregadas foram EDTA 17% (I), NaOCl 1% (II), NaOCl 1% e EDTA 17% (III), e água destilada (IV) (controle). Os dentes foram incluídos em blocos de resina acrílica e cortados transversalmente. A hemi-secção que melhor representou a furca dental foi lixada e polida para a avaliação da microdureza Knoop. As medidas obtidas foram analisadas utilizando-se teste ANOVA seguido do teste de comparação múltipla de Tukey (α=0,05). Os resultados desse estudo mostraram que todas as soluções, exceto o grupo controle, diminuíram a microdureza dentinária. O EDTA não apresentou diferença estatística significante em relação ao NaOCl/EDTA (p>0,05), mas foi diferente do NaOCl (p<0,01). Os grupos do EDTA e NaOCl/EDTA mostraram a maior redução da microdureza. A solução de EDTA 17%, associada ou não ao NaOCl 1% reduz, significantemente, a microdureza dentinária da furca de molares inferiores.