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Introduction: The aim of this in vitro study was to evaluate the effect of various irrigants on the push-out bond strength of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA)., Methods and Materials: A total of 140 dentin disks with a thickness of 1.5±0.2 mm and lumen size of 1.3 mm, were randomly divided into 12 groups ( n =10) and 4 control groups ( n =5). The lumen of disks in groups 1, 2, 3, 7, 8, 9 were filled with CEM and groups 4, 5, 6, 10, 11, 12 were filled with MTA. Control groups were filled with CEM and MTA. Specimens were incubated at 37 ° C for one day in groups 1 to 6 and seven days in groups 7 to 12. After incubation the samples were divided into three subgroups ( n =10) that were either immersed for 30 min in 5.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) or saline solution. The push-out bond strength values were measured by using a universal testing machine. The nature of the failures were determined by light microscope. Data was analyzed using the three-way ANOVA to evaluate the effect of material type, different irrigants and time intervals. Post hoc Tukey's test was used for two-by-two comparison of the groups., Results: CEM cement significantly showed a higher push-out bond strength in comparison with MTA ( P =0.001). The elapse of time significantly increased the bond strength ( P =0.001). There was no significant difference between the irrigants used in this study ( P =0.441). Bond failure was predominantly of mixed type in MTA and of cohesive type in CEM samples., Conclusion: Based on this study, endodontic irrigants did not influence the push-out bond strength of MTA and CEM cement.

Complete eradication of microbial biofilms and elimination of the smear layer are the key factors during endodontic treatment. Various chemical irrigants have been proposed in the literature for the same. The major setback with these chemical irrigants is that they are not bio-friendly to the dental and peri-radicular tissues. In the recent years, research to use natural products for root canal disinfection has gained importance. The aim of this article is to compile various herbal products that have been used as an irrigants and intracanal medicaments in the field of Endodontics to eradicate the biofilm and remove smear layer.

Aim and Objectives: Successful root canal treatment involves the complete elimination of microorganism from the root canal and the three-dimensional obturation of the canal space. Enterococcus faecalis is the most commonly found bacteria in failed root canal. Chemical irrigation of canals along with biomechanical preparation helps in the elimination of microorganisms. The present study was aimed to evaluate the antimicrobial effect of herbal root canal irrigants (Morinda citrifolia, Azadirachta indica extract, Aloe vera) with sodium hypochlorite (NaOCl)., Materials and Methods: The bacterial E. faecalis (ATCC) culture was grown overnight in brain heart infusion (BHI) broth and inoculated in Mueller-Hinton agar plates. Antibacterial inhibition was assessed using agar well diffusion method. All five study irrigants were added to respective wells in agar plates and incubated at 37°C for 24 h. Bacterial inhibition zone around each well was recorded. Results were tabulated and statistically analyzed using Statistical Package for the Social Sciences software for Windows, version 19.0. (IBM Corp., Armonk, NY., Results: Highest inhibitory zone against E. faecalis was seen in NaOCl fallowed by M. citrifolia and A. indica extract, and the least by A. vera extract., Conclusion: Tested herbal medicine (A. indica extract, M. citrifolia, A. vera) showed inhibitory zone against E. faecalis. Hence, these irrigants can be used as root canal irrigating solutions.

The aim of this study was to determine the direct mutagenic potential of any precipitate formed by combining sodium hypochlorite (NaOCl) and chlorhexidine (CHX). The precipitates formed by NaOCl and CHX were dissolved in 100% dimethyl sulfoxide and cultured with mutant Salmonella Typhimurium strains. The cells were observed for reverse mutation. The numbers of positive/mutated wells were statistically compared with those in the background plates using the two-sample proportion independent t-test. The precipitates were not found to be significantly more mutagenic than the background plates. Within the limitations of this study, the results suggest that the precipitates formed when sodium hypochlorite and chlorhexidine contact did not show mutagenic (and are therefore carcinogenic) potential., (© 2015 Australian Society of Endodontology.)

Introduction: Mixing sodium hypochlorite (NaOCl) with chlorhexidine (CHX) forms a brown-colored precipitate. Previous studies are not in agreement whether this precipitate contains para-chloroaniline (PCA). Tests used for analysis may demonstrate different outcomes. Purpose of this study was to determine whether PCA is formed through the reaction of mixing NaOCl and CHX by using high performance liquid chromatography, proton nuclear magnetic resonance spectroscopy, gas chromatography, thin layer chromatography, infrared spectroscopy, and gas chromatography/mass spectrometry., Methods: To obtain a brown precipitate, 4.99% NaOCl was mixed with 2.0% CHX. This brown precipitate was analyzed and compared with signals obtained from commercially available 4.99% NaOCl, 2% solutions, and 98% PCA in powder form., Results: Chromatographic and spectroscopic analyses showed that brown precipitate does not contain free PCA., Conclusions: This study will be a cutoff proof for the argument on PCA formation from reaction of CHX and NaOCl., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Regenerative endodontic procedures for immature teeth with pulp necrosis have gained a lot of interest. Basic scientific research has documented the potential for dental pulp regeneration in preclinical studies. A number of case reports and case series have shown the control of clinical infection and increases in thickness and length of the roots. Preoperative infection is an important factor that predicts outcome in nonsurgical endodontic treatment in mature teeth and seems to also be an important determinant of outcome in treating immature teeth. However, antimicrobial strategies for the immature tooth in which pulp regeneration is contemplated are different from those used in mature cases. This is because of the interest in disinfecting the root canal to a higher level to promote tissue growth without disrupting the bioactive potential of root dentin and the viability of stem cells from which the regenerated tissue would develop. This review addresses the factors involved in making clinical decisions in this area in light of the information available on the microbiology of endodontic infections, the efficacy to antimicrobial strategies, and the outcomes of regenerative and alternative procedures. [ABSTRACT FROM AUTHOR]

Introduction: This study was conducted to investigate whether the interaction between the turbidimetric limulus amebocyte lysate (LAL) substrate for endotoxin measurement and the substances/antimicrobial agents used in endodontic therapy can lead to the inhibition/enhancement of endotoxin recovery., Methods: Ten microliters of a suspension of Escherichia coli endotoxin (O55:B55) was inoculated and kept in contact for 1 hour with different substances categorized as follows: group 1: auxiliary chemical substances: 5.25% and 2.5% sodium hypochlorite solutions, 2% chlorhexidine (CHX) (gel and solution), 1% Natrosol gel (Drogal Chemicals and Pharmaceuticals Ltd, Piracicaba, SP, Brazil), 17% EDTA, 10% citric acid, 3% hydrogen peroxide, 5% sodium thiosulfate, and 0.5% Tween 80 associated with 0.07% soy lecithin (Drogal Chemicals and Pharmaceuticals Ltd) and group 2: intracanal medications: neomycin/polymyxin B/hydrocortisone (Otosporin; Glaxo Wellcome, Rio de Janeiro, RJ, Brazil); calcium hydroxide (Ca[OH]2); Ca(OH)2 + 2% CHX gel; Ca(OH)2 + 2% CHX gel + zinc oxide eugenol; Ca(OH)2 + camphorated paramonochlorophenol (Calen; S.S. White, Rio de Janeiro, RJ, Brazil); triple antibiotic paste; mineral trioxide aggregate (MTA); and iodoform. Positive and negative controls consisted of root canal hemorrhagic exudate and pyrogen-free sterile water, respectively. All samples were diluted up to a 10:4 dilution. Each dilution was individually examined by the turbidimetric LAL assay. Collected data were analyzed through performance characteristics of the LAL assay such as linearity, coefficient of variation percentage, and product positive control (PPC) values., Results: Correlation coefficient (≥0.980) and coefficient of variation percentage (<10%) of the standard curve in triplicate showed the tests' linearity. Spike recovery of auxiliary chemical substances achieved PPC values ranging from 50%-197%, showing no interferences with LAL substrate. Conversely, 3% hydrogen peroxide achieved product inhibition in which endotoxin values were underestimated even after the 10:4 dilutions. Regarding intracanal medicaments, neomycin/polymyxin B/hydrocortisone also inhibited endotoxin detection in all dilutions investigated (PPC values <50%). In contrast, Ca(OH)2 + 2% CHX gel + ZOE as well as triple antibiotic paste led to the enhancement of endotoxin detection in which endotoxin values could not be validated by the turbidimetric kinetic LAL assay (PPC value >200%)., Conclusions: The performance characteristics of the kinetic turbidimetric assay for endotoxin measurement, such as precision and reproducibility, are modulated by the interaction of the LAL substrate with the substances/antimicrobial agents used in endodontic therapy., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: In this experimental study, the amount of smear layer (SL) remnants in curved root canals after chemomechanical instrumentation with two engine-driven systems or hand instrumentation was evaluated., Methods and Materials: Forty-eight mesiobuccal roots of mandibular first molars with curvatures ranging between 25 and 35 degrees (according to Schneider's method) were divided into three groups (n=16) which were prepared by either the ProTaper Universal file series, Reciproc single file system or hand instrumentation. The canals were intermittently irrigated with 5.25% NaOCl and 17% (ethylenediaminetetraacetic acid) EDTA, followed by distilled water as the final rinse. The roots were split longitudinally and the apical third of the specimens were evaluated under 2500× magnification with a scanning electron microscope (SEM). The mean scores of the SL were calculated and analyzed using the non-parametric Kruskal-Wallis and Mann-Whitney U tests., Results: The mean scores of the SL were 2.00±0.73, 1.94±0.68 and 1.44±0.63 µm for the ProTaper Universal, Reciproc and hand instrumentation, respectively. Mean score of SL was significantly less in the hand instrumentation group than the ProTaper (P=0.027) and Reciproc (P=0.035) groups. The difference between the two engine-driven systems, however, was not significant (P=0.803)., Conclusion: The amount of smear layer in the apical third of curved root canals prepared with both engine-driven systems was similar and greater than the hand instrumentation technique. Complete cleanliness was not attained.

Aims: The purpose of this ex vivo study was to evaluate and compare the weight of debris and volume of irrigant extruded apically from teeth using different preparation techniques., Subjects and Methods: Thirty extracted human mandibular premolars with single canals and similar lengths were instrumented using hand ProTaper F2 (25, 0.08; Dentsply Maillefer, Ballaigues, Switzerland), M-two (25, 0.06; VDW, Munich, Germany) and WaveOne Primary (25, 0.08; Dentsply Maillefer, Ballaigues, Switzerland). Debris and irrigant extruded during instrumentation were collected into preweighed Eppendorf tubes. The volume of the irrigant was measured, and then the tubes were stored in an incubator at 70°C for 2 days. The Eppendorf tubes were weighed to obtain the final weight when the extruded debris was included. Three consecutive weights were obtained for each tube., Statistical Analysis Used: Data were statistically analyzed by one-way analysis of variance and Student's t-test., Results: There were no statistically significant differences among the groups. The WaveOne reciprocating system showed the maximum amount of apical extrusion of debris and irrigant among all the groups. The least amount of debris and irrigant was observed in ProTaper hand instrument (P > 0.05)., Conclusion: All instrumentation techniques were associated with debris and irrigant extrusion.

Background: The objective of this study was to compare the efficiency of four commonly used chemicals in their ability to remove smear layer after instrumentation using scanning electron microscope (SEM)., Materials and Methods: Seventy-five extracted single canaled teeth of roots ranging 10-12 mm in length were used for the study. Teeth were divided into 4 study groups and 1 control group of 15 teeth each. Standard access to the pulp chambers were performed with diamond burs. The lengths of the teeth were determined by the introduction of a size 15 K-file into the root canal until the tip reached the apical foramen. The working length for preparation of the canal is set 0.5 mm shorter than the measurement. Irrigation was performed using 2 ml of irrigant for every instrument change and finally rinsed using 5 ml of the respective solutions. The roots were then split with a chisel and hammer. One-half of each tooth was selected and prepared for SEM examination. After assembly on coded stubs, the specimens were placed in a vacuum chamber and sputter-coated with a 300 Å gold layer. The specimens were then analyzed using a Philips SEM XL 30. The dentinal wall of the cervical, middle and apical thirds was observed at magnifications of up to ×1000 for the presence/absence of smear layer and visualization of the entrance to dentinal tubules. Photomicrographs (×1000) of these areas on each of the coronal, middle and apical thirds were made Data were analyzed using Kruskal-Wallis test and Mann-Whitney U test., Results: SEM study done on these prepared teeth with the popularly used four chemicals, namely, 3% NaOCl (Group A), 3% NaOCl followed by 17% ethylene diamine-tetra-acetic acid (Group B), 0.2% chlorhexidine (Group C) and 3% NaOCl followed by MTAD (Group D), with distilled water (Group E) which is used as control, revealed that NaOCl showed statistically significant, better cleansing effect than distilled water. Chlorhexidine and NaOCl showed equal kind of efficacy but were statistically significant, with lower efficacy than MTAD. It may be concluded that MTAD appears to be the most effective solution compared to the rest., Conclusion: The study demonstrated that MTAD as a final rinse after the entire instrumentation with 3% NaOCl as irrigant provided the best cleansing in all parts of the root canal system. The smear layer has been shown to hinder the penetration of intracanal disinfectants and sealers into dentinal tubules and has the potential of compromising the seal of the root filling. Degradation of the smear layer after treatment may contribute to leakage and reinfection of the root canal space. Removal of the smear layer reduced the penetration of bacteria through the root canal system after root filling.

Unlabelled: Enterococcus faecalis is the most isolated or detected species from oral infections including marginal periodontitis, infected root canals, periradicular abscesses and also detected in cases of failed endodontic therapy. To prevent endodontic treatment failure irrigation is mandatory for the effective removal of smear layer, pulp tissue, and microorganisms. Cultivation and other traditional identification methods have been demonstrated to have several limitations when it comes to microbiological identification. Polymerase chain reaction was selected because it has an added advantage over traditional microbiological methods., Materials and Methods: Twenty single rooted premolars were taken were taken stored in 0.1% thymol solution at 4°C decoronated to obtain 12 mm length, teeth were autoclaved at 121°C, canals were instrumented up to 35k file (International Organization for Standardization). The samples were randomly divided into three groups Group I - 5.25% sodium hypochlorite (NaOCL) and 17% ethylenediaminetetraacetic acid (EDTA), Group - II 5.25% NaOCL and 2% chlorhexidine (CHX), Group III - 5.25% NaOCL and 17% EDTA and 2% CHX., Results: The results showed that Group III which is 5% NaOCl followed by 17% EDTA and followed by 2% CHX showed maximum antimicrobial activity in all the three different time intervals.

Aim: Irrigant usage information in relation to years of professional experience was collected from general dentists in different German federal states by means of a questionnaire., Methodology: A short survey concerning endodontic treatment and use of irrigants was mailed to 4240 dentists or delivered to 3720 dental offices as an extra page in a journal in eight German states. Detailed information concerning the most frequently used irrigants, their concentrations, the spectrum of disinfectants used in root canal treatment concepts for vital and nonvital pulps, main topics of continuing education as well as years of professional experience was collected. The statistical analysis of differences found amongst the dentists in relation to professional experience or federal state was performed using the chi-square test., Results: Of a total of 7960 invitations, 1630 replies were evaluated (response rate 20.5%). The majority of the dentists (57.3%) had >20 years of professional experience, 23% had >30 years. Dentists with long-standing professional experience (20-30 years) used H2 O2 significantly more often than dentists with less experience (P < 0.001), and of the older colleagues (>30 years of professional experience), 14.6% never used NaOCl, whilst the younger colleagues almost always used it (P < 0.001). Differences were also found for the usage of irrigants amongst dentists from the various German states., Conclusions: Whilst NaOCl was used in almost all states, regional differences were found regarding the choice of additional irrigants, which were mainly determined by the irrigation protocols taught at different universities., (© 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Purpose: The aim of the present study was to evaluate and to compare the antibacterial effects of various irrigation solutions against Staphylococcus aureus (S. aureus) in human root canals., Materials and Methods: 120 single-root mandibular premolar teeth were selected. The teeth were prepared and sterilized. S. aureus was incubated in the root canals and kept at 37°C for 24h. The infected root canals were divided into one positive (saline) and one negative (sodium hypochlorite) control, and four experimental groups [Ethylene-diaminetetra-aceticacid, Chlorhexidine Gluconate, Super-oxidized water(SPO), Aqueous ozone] (n=20). Flow rate of irrigation was applied with 5 mL/min flow rate for 3 min to ensure standardization among all study groups. Following the irrigation, paper points were placed in the root canals and then transferred in sterile eppendorf. Remaining bacteria were counted on blood agar plates and the data were analyzed using one-way ANOVA and Tukey's test., Results: Although there were statistically significant differences among SPO and other experimental groups (p<0.05), there was no statistically significant difference between SPO and NaOCl (p>0.05)., Conclusion: Super-oxidized water may be recommended as an alternative irrigation solution instead of NaOCl against S. aureus in root canals., Competing Interests: Conflict of interest: None declared.

Introduction: This study compared the influence of different irrigants with and without ultrasound or laser irradiation on the bond strength of glass fiber posts using a self-etching adhesive in a supplementary dentin pretreatment., Methods: Ninety bovine incisor roots were divided into 3 groups according to the irrigant tested: 2% chlorhexidine (CHX) (n = 30); 2.5% sodium hypochlorite (NaOCl) (n = 30), and saline solution (control) (n = 30). Each group was randomly divided into 3 subgroups according to the supplementary dentin pretreatment: ultrasound, Nd:YAG laser, and nonsupplemented (control). A self-etching adhesive system (Futurabond DC; VOCO GmbH, Cuxhaven, Germany) was used, and the glass fiber posts were cemented with dual-cure epoxy-based luting agent (Bifix QM, VOCO GmbH). All roots were sectioned transversely, and the push-out test was performed. Failure mode analysis was also evaluated., Results: Bond strength decreased significantly after the use of 2.5% NaOCl in all root thirds (P < .05). CHX showed no difference in the mean bond strength value compared with saline solution (P > .05). The supplementary dentin pretreatment using the Nd:YAG laser or ultrasound did not improve the bond strength values for both NaOCl and CHX (P > .05). Moreover, the apical third exhibited the lowest mean bond strength values (P < .05). Analysis indicated that the predominant failure mode was the mixed type., Conclusions: Regardless of the irrigant used, the supplementary dentin pretreatment with ultrasound or laser irradiation showed no improvement in bond strength. Also, the use of NaOCl decreased the bond strength of glass fiber posts using a self-etching adhesive system, whereas CHX preserved it., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aim: To evaluate the effect of several final irrigants on the adhesion force (Fad) between dentine and resin-based sealers by means of atomic force microscopy (AFM)., Methodology: Twelve distal roots of mandibular molars were used. The roots were smoothened and cut to obtain 36 specimens. During chemomechanical preparation of the root canals, 5.25% NaOCl was used as the irrigant. The specimens were then divided into six groups according to the final irrigant used: control group - immersed in distilled water (DW) for 1 min; chlorhexidine (CHX) group - in 2% CHX for 1 min; NaOCl group - in 5.25% NaOCl for 1 min; EDTA group - in 17% EDTA for 5 min, EDTA/CHX group - in EDTA, followed by intermediate flushing with DW and then immersed in CHX; EDTA/NaOCl group - in EDTA, followed by intermediate flushing with DW and then immersed in NaOCl. After the treatments, all groups were washed with DW to remove all traces of the irrigants. Afterwards, the samples were dried and attached to a glass base. AFM tips containing AH Plus and Real Seal SE sealers were used to obtain force-distance curves with regard to dentine-treated surfaces. Data were analysed statistically using nonparametric tests with the significance level set at P < 0.05., Results: In the groups with smear layer, a final flush with CHX and NaOCl resulted in significantly higher Fad values than the control group for both sealers (P < 0.001). When smear layer was removed, the highest Fad values associated with AH Plus occurred with a final flush of NaOCl, whilst in Real Seal SE, the highest values were found with a final flush of CHX (all results significant at P < 0.001)., Conclusion: Irrigants had a positive effect on the adhesion of the resin-based sealers, AH Plus and Real Seal SE, to dentine., (© 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Abstract Vivacqua-Gomes N, Ferraz CCR, Gomes BPFA, Zaia AA, Teixeira FB, Souza-Filho FJ . Influence of irrigants on the coronal microleakage of laterally condensed gutta-percha root fillings. International Endodontic Journal , 35 , 791–795, 2002. Aim To assess in vitro coronal microleakage in extracted human teeth after root-canal treatment, using different endodontic irrigants. Methodology Fifty teeth with single root canals were prepared and filled using the lateral condensation of gutta-percha and Endométhasone sealer. Canal preparation consisted of initial shaping of the coronal two-thirds with Gates-Glidden burs size 2 and 3, followed by preparation of the apical stop and step-back flaring with manual files. Each group (n = 10) was irrigated with the following solutions: I – 1% NaOCl, II – 1% NaOCl + 17% EDTA, III – 2% chlorhexidine gel, IV – 2% chlorhexidine gel + 1% NaOCl, and V – distilled water. After root-canal filling, the teeth were incubated at 37 °C for 10 days followed by 10 days immersion in human saliva and an additional 10 days in India ink. The teeth were cleared and maximum dye penetration was determined digitally in millimetres. Statistical analysis was carried out using the Kruskal–Wallis test. Results Least leakage occurred with 1% NaOCl + 17% EDTA (2.62 mm) and 2% chlorhexidine gel (2.78 mm) (P > 0.05). NaOCl (3.51 mm), distilled water (6.10 mm) and 2% chlorhexidine gel + 1% NaOCl (9.36 mm) gave increased leakage with a significant difference compared to NaOCl + 17% EDTA and 2% chlorhexidine gel, and compared to one another (P < 0.05). Conclusions Under the condition of this study, irrigation method during root-canal treatment influenced coronal microleakage. NaOCl + EDTA and chlorhexidine gel allowed better sealing following root filling. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this in vitro study was to evaluate and compare the antimicrobial substantivity of different concentrations of chlorohexidine as root canal irrigant by microbiological assay using mitis salivarius bacitracin streptomycin, MSBS agar plate., Methods: Extracted single rooted permanent human teeth were selected as samples and randomly divided into four groups (three experimental, one control). The samples of the three experimental groups used different concentration of chlorhexidine, CHX (0.1%, 1% and 2%), deionized water used as an irrigant served as control. In each group the apices of teeth were sealed with composite and mounted on plaster blocks. Root canals were prepared using step back technique and enlarged upto no 80. With each change in the file size the corresponding irrigant was used and final irrigation was done with deionized water. Samples were taken with paper points at 12 h, 1 day, 2 days and 3 days respectively and stored in sterile phials which were then arranged on MSBS agar plates for microbiological assay., Results and Conclusion: Results were analysed by ANOVA and Tukey's HSD test showed that antibacterial substantivity of 2% CHX was best followed by 1% CHX and 0.1% CHX in decreasing order respectively.

Laser enhancement of ethylenediaminetetraacetic acid with cetrimide (EDTAC) has previously been shown to increase removal of smear layer, for middle-infrared erbium lasers. This study evaluated the efficiency of EDTAC activation using a near-infrared-pulsed 940 nm laser delivered by plain fibre tips into 15% EDTAC or 3% hydrogen peroxide. Root canals in 4 groups of 10 single roots were prepared using rotary files, with controls for the presence and absence of smear layer. After laser treatment (80 mJ pulse(-1) , 50 Hz, 6 cycles of 10 s), roots were split and the apical, middle and coronal thirds of the canal were examined using scanning electron microscopy, with the area of dentine tubules determined by a validated quantitative image analysis method. Lasing EDTAC considerably improved smear layer removal, while lasing into peroxide gave minimal smear layer removal. The laser protocol used was more effective for smear layer removal than the 'gold standard' protocol using EDTAC with sodium hypochlorite (NaOCl). In addition, lasers may also provide a benefit through photothermal disinfection. Further research is needed to optimise irrigant activation protocols using near-infrared diode lasers of other wavelengths., (© 2013 Australian Society of Endodontology.)

Objectives: The effects of different EndoActivator® (EA) sonic activation protocols on root canal debridement efficacy were examined., Methods: Root canals in 48 single-rooted teeth were instrumented, irrigated initially with NaOCl and divided into 6 groups (N=8) based on the application time of QMix (antimicrobial calcium-chelating irrigant), and the time and sequence of EA irrigant activation - Positive Control: 90s QMix; Negative Control: 90s saline; Group 1A: 15s QMix+15s QMix with EA-activation; Group 1B: 30s QMix+30s of QMix with EA-activation; Group 2A: 15s QMix with EA-activation+15s QMix; Group 2B: 30s QMix with EA-activation+30s QMix. Split roots were examined with scanning electron microscopy for assignment of smear and debris scores in locations along the coronal, middle and apical thirds of the canals. The overall cleanliness of pooled canal locations in the Positive Control and the 4 experimental groups were compared with chi-square tests., Results: Significant differences were detected among the 5 groups (P<0.001). Post hoc pairwise comparisons indicated that the overall canal cleanliness was in the order (from best to worst): 1B=2B>2A>1A>Positive Control. Completely clean canals could not be achieved due to the absence of continuous irrigant flow for EA to clear intraradicular debris., Conclusions: Irrespective of the sonic activation sequence, irrigant activation for 30s during a 60-s period of QMix application appears to maximise the smear layer and debris removal potential of the EndoActivator® system., Clinical Significance: Sonic activation of root canal irrigants produces cleaner root canals and reduces the time required for final delivery of a canal wall smear later-removing irrigant when compared to the use of needle irrigation alone., (Published by Elsevier Ltd.)

Antibiotics are systemically and locally used extensively in endodontics. However, local antibiotic application mode is considered more effective than systemic administration. The local mode enables the dentist to target bacteria in every nook and corner of root canal system, which is otherwise beyond reach if targeted by instrumentation or conventional root canal treatment protocols. Therefore, they are an important adjunct to conventional treatment of root canal. The present study reviews the various antibiotic containing dental agents used in endodontics. A web-based research on MedLine was performed with terms Review Articles published in the last 10 year's dental journals in English for literature researching, extracting, and synthesizing data. Relevant articles were shortlisted. Important cross-reference articles were also reviewed.

Objective: Canal preparation generates a substantial amount of debris and smear layer (SL). The size and taper of the Master Apical File (MAF) affects on penetration of irrigants and subsequently canal cleaning efficacy. The aim of this study was to evaluate the effect of MAF size and taper on penetration of irrigants to the apical third of curved mesiobuccal (MB) canals of mandibular first molars., Materials and Methods: Eighty-nine human mandibular first molars were divided into one control group (n=5) without rotary instrumentation and 6 experimental groups (n=14 each) that were prepared with the following RaCe rotary files as MAF: 25.04 (group1), 25.06 (group 2), 30.04 (group 3), 30.06 (group 4), 35.04 (group 5) and 35.06 (group 6). All the experimental groups were rinsed with 2 ml of 17 % EDTA followed by 2 ml of 5.25% NaOCl. Debridement of the MB canals was evaluated using scanning electron microscope (SEM). The data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests (P<0.05)., Results: Group 6 (MAF=35.06) showed 100% acceptable debridement. This rate was 92.9% for MAF=35.04. In group 4 (MAF=30.06) smear layer (SL) was removed in the three-forth of the samples and debris was removed in 92.9% of them. Acceptable debridement was not achieved in most samples of groups 1 and 2 (25.04 and 25.06, respectively) and the mentioned two groups had statistically significant difference in this respect with the other groups (P<0.05)., Conclusion: Based on this study, 30.06 may be considered as the minimum MAF size for acceptable debridement.

Introduction: One of the essential factors for successful root canal therapy is elimination of bacterial contaminants using an effective root canal chemical irrigant such as sodium hypochlorite which inherently possesses certain disadvantages like irritation to periapical tissues, staining of the instruments, burning of surrounding tissues etc. The aim of the study was to explore newer irrigant agents which would probably be as effective or more and at the same time less irritating to the tissues than sodium hypochlorite. Our search included two such agents, propolis and miswak., Methods: The study was performed on 40 infected primary teeth (20 male and 20 female patients). The subjects were divided into 4 groups of 10 children. Group 1 received 3% sodium hypochlorite as irrigating solution, group 2 received 12.5% alcoholic extract of miswak, group 3 received 11% alcoholic extract of propolis and group 4, 0.9% saline. We used the antimicrobial activity of sodium hypochlorite as gold standard for comparing the activities of both propolis and miswak. We collected pre- and post-irrigation samples using sterile paper points. Samples were cultured on tryptose soya agar at a temperature of 37(o)C for 24-48 hours. The colonies were counted with a digital colony counter. For the statistical analysis, we used the unpaired t test at level of significance 0.05 and the ANOVA test for analysis of variance., Results: The differences in pre- and post- irrigation values were calculated for each group, the greatest difference being seen in group 1 (95.549%) followed by group 2 (89.794%), group 3 (34.735%) and group 4 (28.087%). When comparing the results between groups, there was no statistically significant difference between groups 3 and 4., Conclusions: The statistically analyzed results suggested that miswak could be a good natural substitute to sodium hypochlorite, while propolis showed results comparable to those of the negative control.