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The outcome of endodontic therapy is directly related to the control of infection. The aim of the study was to evaluate in vitro the efficacy of Simvastatin (SIM) and diclofenac (DC) solutions on endodontic biofilms., Methods: Mature biofilms were grown on dentin specimens and put in contact with the solutions to determine their antibiofilm activity. To assess residual antimicrobial activity, the dentin samples were immersed for 5 min in the solutions before microbial infection for 3 weeks. The study groups were: (1) 8% SIM, (2) 4% SIM, (3) 4% DC, (4) 2.5% sodium hypochlorite (NaOCl), and (5) 0.9% saline solution (SS). Cell viability was evaluated by means of the adenosine triphosphate (ATP) assay and flow cytometry (FC). The data collected were analyzed with the ANOVA test using Welch's correction followed by the Games-Howell test. The level of statistical significance was p < 0.05, and statistical analysis was performed using SPSS 23.0., Results: All study groups reduced the biofilms significantly with respect to the control. The highest reduction percentage was obtained by 2.5% NaOCl, followed by SIM 8% and 4%, without statistically significant differences. In terms of residual activity, the 4% DC solution obtained a higher percentage of dead cells., Conclusion: Solutions of 4% and 8% SIM, and 4% Diclofenac, show antimicrobial and residual activity against multispecies endodontic biofilms.

Background: Using endodontic sealers with long-term antimicrobial properties can increase the success of endodontic treatment. This study aimed to assess the antimicrobial activity over time of two calcium silicate (CS)-based sealers, AH Plus Bioceramic and BioRoot RCS, and to compare them with an epoxy resin-based sealer, AH Plus Jet, against mature polymicrobial biofilms grown on human radicular dentin., Methods: The antimicrobial activity of the sealers was tested using a direct contact test after 1 and 6 weeks of contact with the biofilms. Cell viability was determined by the adenosine triphosphate (ATP) method and flow cytometry (FC). The results of the ATP test were analyzed using an ANOVA with Welch's correction, followed by the Games-Howell test. The number of cells with damaged membranes obtained by FC in each period was compared by means of an ANOVA and Duncan's test. For the comparison between times, a Student's t -test was used., Results: Globally, after a week of contact, the epoxy resin-based sealer obtained the best results. However, at 6 weeks, the two CSs showed the highest antimicrobial efficacy, with a significant increase in this activity over time., Conclusions: Calcium silicate-based sealers exert long-term antimicrobial activity against endodontic biofilms.

The objective of this research was to evaluate the efficacy of diclofenac sodium solutions, with or without cetrimide (CTR) added, against polymicrobial root canal biofilms grown in dentin specimens. The study groups were: (1) 5% diclofenac sodium (DCS); (2) 2.5% DCS; (3) 2.5% DCS + 0. 2% CTR; (4) 2.5% DCS + 0.4% CTR and (5) 0.9% saline solution (SS) as the control. After 5 min of solution contact with the biofilms, the antimicrobial activity was evaluated by means of the adenosine triphosphate (ATP) assay as well as confocal laser scanning microscopy (CLSM). Microbial quantification was indicated as the percentage reduction of relative light units (RLUs) for the ATP assay, the Log 10 total biovolume and the viability percentage (green cells) for CLSM. Solutions of 2.5% DCS + 0.4% CTR and 5% DCS showed the highest antimicrobial efficacy. Cetrimide increased the antibiofilm activity of diclofenac sodium against endodontic biofilms., (© 2023 The Authors. Australian Endodontic Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Endodontology Inc.)

Objectives: The impact of conservative instrumentation on the disinfection of root canals with different curvatures has not yet been determined. This ex vivo study aimed to evaluate and compare the effect of conservative instrumentation with TruNatomy (TN) and Rotate and a conventional rotary system, ProTaper Gold (PTG), on root canal disinfection during chemomechanical preparation of straight and curved canals., Materials and Methods: Ninety mandibular molars with straight (n = 45) and curved (n = 45) mesiobuccal root canals were contaminated with polymicrobial clinical samples. Teeth were divided into three subgroups (n = 14) according to the file systems and the curvature. Canals were instrumented with TN, Rotate, and PTG, respectively. Sodium hypochlorite and EDTA were used as irrigants. Intracanal samples were taken before (S1) and after (S2) instrumentation. Six uninfected teeth were used as negative controls. The bacterial reduction between S1 and S2 was measured by ATP assay, flow cytometry, and culture methods. Kruskal-Wallis and ANOVA tests were followed by the Duncan post hoc test (p < 0.05)., Results: Bacterial reduction percentages were similar for the three file systems in straight canals (p > 0.05). However, PTG showed a lower reduction percentage of intact membrane cells in flow cytometry than TN and Rotate (p = 0.036). For the curved canals, no significant differences were obtained (p > 0.05)., Conclusion: Conservative instrumentation of straight and curved canals using TN and Rotate files resulted in similar bacterial reduction compared to PTG., Clinical Relevance: The disinfection efficacy of conservative instrumentation is similar to conventional instrumentation in straight and curved root canals., (© 2023. The Author(s).)

Persistent infections have become a challenge in dentistry because of growing antibiotic resistance. Nonsteroidal anti-inflammatory drugs (NSAIDs) appear to be a therapeutic alternative to control biofilm infection. The objective of this work is to evaluate the antimicrobial activity and cytotoxicity of sodium diclofenac (DCS), ibuprofen (IBP) and ibuprofen arginine (IBP-arginine) solutions against endodontic polymicrobial biofilms. Sterile radicular dentin blocks of 4 mm × 4 mm × 0.7 mm were used as substrate to grow biofilm. The dentin blocks were submerged into solutions for 5 min. The antimicrobial activity was evaluated by means of the adenosine triphosphate (ATP) assay and confocal laser scanning microscopy (CLSM). Fibroblasts 3T3-L1 (ECACC 86052701) were used to test the cytotoxicity of irrigating solutions. The antibiofilm effects determined by the ATP assay showed that 4% IBP-arginine solution exerted the highest antibiofilm activity, followed by 4% DCS and 4% IBP, with statistical differences among groups ( p < 0.001). As for CLSM, 4% DCS and 4% IBP-arginine solutions gave the lowest viable cell percentages, without significant differences between them. Cytotoxicity results at 1/10 dilution were similar for all solutions. At 1/100 dilution, a 4% DCS solution obtained the lowest cell viability for both time periods assayed, 1 h and 24 h. The IBP-arginine group showed the highest cell viability at 24 h. In this preliminary study, in terms of antibiofilm activity and cytotoxicity, a mixed 4% IBP-arginine solution gave the most promising results. NSAID solutions could be recommendable drugs for endodontic disinfection procedures.

Aim: There is a need to explore new alternatives for root canal disinfection in regenerative endodontics, since the current strategies are far from ideal. Currently, the potential use of diclofenac (DC) is being investigated for controlling root canal infections. The objective was to evaluate the antimicrobial efficacy of novel DC-based hydrogels (DCHs) against polymicrobial biofilms grown in radicular dentine and root canals and to compare results with triantibiotic (TAH) and diantibiotic (DAH) hydrogels, and calcium hydroxide (Ca[OH] 2 )., Methodology: The in vitro antimicrobial activity of intracanal medicaments was evaluated against 3-week-old polymicrobial root canal biofilms grown on human radicular dentine. Dentine samples were obtained and randomly divided into the study groups (n = 4/group): (1) 1 mg/ml TAH; (2) 1 mg/ml DAH; (3) 5% diclofenac (DCH); (4) 2.5% DCH; (5) 1.25% DCH; (6) 1 mg/ml DAH + 5% DCH; (7) Ca(OH) 2 paste; (8) positive control. The microbial viability, in terms of percentage of intact cell membranes, was assessed after 7 days by confocal scanning laser microscopy (CSLM). The ex vivo efficacy of intracanal medications was evaluated in root canals infected with a polymicrobial suspension. Intracanal microbiological samples at baseline (S1) and 7 days post-treatment (S2) were taken; microbial quantification and cell viability were assessed by quantitative polymerase chain reaction (qPCR) and flow cytometry (FC). The mean Log 10 of bacterial DNA copies in root canal samples before (S1) and the Log 10 reduction of DNA copies S1-S2 in qPCR were recorded. The absolute value of total cells stained, and the percentage reduction of intact membrane cells after treatment (S1-S2), were analysed by FC. Global comparison was done using the Kruskal-Wallis test, whilst the Mann-Whitney U test was used for pair-by-pair comparison., Results: Confocal scanning laser microscopy analysis indicated that the greatest effectiveness was obtained with 5% DCH, showing significant differences with respect to the other groups (p < .001). In root canals, the highest Log 10 DNA reduction S1-S2 was obtained with 5% DCH and TAH, with no differences between them. The results of FC showed that only 5% DCH proved significantly superior to the other treatments., Conclusions: Sodium DC hydrogels demonstrate antimicrobial efficacy against endodontic biofilms., (© 2022 British Endodontic Society. Published by John Wiley & Sons Ltd.)

Dental caries is the major biofilm-mediated oral disease in the world. The main treatment to restore caries lesions consists of the use of adhesive resin composites due to their good properties. However, the progressive degradation of the adhesive in the medium term makes possible the proliferation of cariogenic bacteria allowing secondary caries to emerge. In this study, a dental adhesive incorporating a drug delivery system based on L-arginine-containing mesoporous silica nanoparticles (MSNs) was used to release this essential amino acid as a source of basicity to neutralize the harmful acidic conditions that mediate the development of dental secondary caries. The in vitro and bacterial culture experiments proved that L-arginine was released in a sustained way from MSNs and diffused out from the dental adhesive, effectively contributing to the reduction of the bacterial strains Streptococcus mutans and Lactobacillus casei. Furthermore, the mechanical and bonding properties of the dental adhesive did not change significantly after the incorporation of L-arginine-containing MSNs. These results are yielding glimmers of promise for the cost-effective prevention of secondary caries., (© 2022. The Author(s).)

Biodentine (BD) is a bioactive material with many indications in endodontic therapy. The purpose of this study was to compile and review the outcomes of in vitro and in vivo studies of BD in terms of antimicrobial effectiveness. An electronic search was carried out in PubMed, from January 2009-April 2021 using the keywords: (Biodentine or dentine substitute or "Ca 3 SiO 5 " or tricalcium silicate cement or bioceramic cement) and (antimicrobial activity or antimicrobial effect or antimicrobial effectiveness or antibacterial activity or antibacterial effect or antibacterial effectiveness or antibiofilm activity or antibiofilm effectiveness). Two independent reviewers evaluated the studies for eligibility. All studies that did not include BD or its antimicrobial properties, as well as abstracts not written in English, were excluded. This review identified the need to develop standardized methods to evaluate antimicrobial activity in vitro. Most of the studies were against planktonic bacteria and gave conflicting results. Studies ex vivo and in vivo against biofilm are required to elucidate the antimicrobial activity of BD.

Objectives: The objectives of this study are to investigate, over time, the antimicrobial activity against polymicrobial biofilms and ability to inhibit biofilm formation, of Biodentine (BD) alone and with 5% and 10% sodium diclofenac (DC)., Material and Methods: The antimicrobial activity of BD alone and modified with 5% and 10% DC against polymicrobial biofilm growth in dentin was determined by a modified direct contact test. The study groups were (1) BD; (2) BD + 5% DC; and (3) BD + 10% DC. The viability of microorganisms after 1 and 4 weeks was quantified by means of an ATP assay and flow cytometry. The antibiofilm efficacy of the materials, preventing polymicrobial biofilm formation over time, was assessed by confocal laser scanning microscopy (CLSM)., Results: The results obtained with both the ATP test and flow cytometry showed that BD alone and with 5% and 10% DC exerted antibiofilm activity with respect to the control, in the two evaluated times (p < 0.001). Comparison between groups showed a tendency of increased antimicrobial effect, both over time and depending on the DC concentration. These results coincide with those obtained in CLSM analysis, where efficacy increased with time and DC concentration., Conclusions and Clinical Relevance: Biodentine, over time, showed antimicrobial and antibiofilm efficacy on polymicrobial biofilms. The addition of 5% and 10% DC to BD enhanced this effect, in a concentration- and time-dependent manner., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The relative citation rate (RCR) is a normalized article-level metric useful to assess the impact of research articles. The objective of this bibliometric study is to identify and analyze, in root canal disinfection, the 100 articles having the highest RCRs in the period 1990-2019, then compare them with the top 100 articles most cited. A cross-sectional study was performed, and the search strategy ((Disinfection AND root canal) AND (("1990/01/01"[Date-Publication]: "2019/12/31"[Date-Publication]))) relied on PubMed ( n = 4294 documents), and article data were downloaded from the iCite database. The 100 articles with the highest RCRs and the top 100 cited were selected and evaluated in bibliometric terms. Among the 100 articles with the highest RCRs, there were no differences in the three decades for RCRs values, but there were in citations, being 2000-2009 the most cited. The USA was the predominant country ( n = 30), followed by Brazil ( n = 14). The most frequent study designs were reviews ( n = 27) and in vitro ( n = 25) and ex vivo ( n = 24) studies. All subfields were well represented, although they varied over time. In 2010-2019, regenerative procedures and irrigation/disinfection techniques were predominant. Considering the RCR's top 100 articles, 76 were common with the 100 most cited articles. Using the RCR metric allowed us to identify influential articles in root canal disinfection, a research field with topics of significance that fluctuate over time. Compared to citations, RCR reduces the time from publication to detection of its importance for the readership and could be a valid alternative to citation counts.

Introduction: The aim of this study was to compare the antibiofilm effects of a triple antibiotic solution (TAS); a double antibiotic solution (DAS); and 5%, 2.5%, and 1.25% diclofenac solutions (DCSs) against Enteroccocus faecalis biofilm., Methods: Eighty-four sterile radicular dentin blocks were used as biofilm substrate for 3 weeks. The study groups were as follows: (1) 1 mg/mL TAS (minocycline, metronidazole, and ciprofloxacin), (2) 1 mg/mL DAS (metronidazole and ciprofloxacin), (3) 5% DCS, (4) 2.5% DCS, (5) 1.25% DCS, and (6) 0.9% saline solution. The antimicrobial activity was evaluated by bacterial count determinations and confocal laser scanning microscopy. The contact time for the antimicrobial tests was 5 minutes. Bacterial counts were expressed as the reduction percentage of colony-forming units; for the confocal laser scanning microscopic evaluation, the log 10 total biovolume and percentage of green population (live cells) were calculated., Results: The colony-forming unit reduction percentage ranged between 62.98 and 98.62, respectively, for TAS and 5% DCS. The DCS showed a concentration-dependent effect.For the confocal laser scanning microscopy, the log 10 total biovolume in all groups was very similar and showed a scarce (1.39-1.02) but significant reduction with respect to the control; 5% and 2.5% DCSs gave the lowest viable cell percentage. The TAS and DAS groups showed intermediate values without significant differences between them., Conclusions: DCSs at 5% and 2.5% have greater antimicrobial effects than TAS and DAS and may be considered a valid alternative for controlling the infection of teeth with apical periodontitis., (Copyright © 2021 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

The aim of this study is to determine the cytotoxic effects of tetrasodium ethylenediaminetetraacetic acid (EDTANa 4 ) 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% EDTANa 4 ; group 3, 20% EDTANa 4 ; group 4, 2.5% NaOCl/5% EDTANa 4 ; group 5, 2.5% NaOCl/10% EDTANa 4 ; group 6, 2.5% NaOCl/5% EDTANa 4 /0.2% CTR; group 7, 2.5% NaOCl/10% EDTANa 4 /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 EDTANa 4 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 EDTANa 4 showed moderate cytotoxic effects when compared with NaOCl alone.

The sealers' antibacterial and antibiofilm activities against Enterococcus faecalis were evaluated by direct contact test (DCT) and confocal laser scanning microscopy (CLSM), respectively, after 1 day, and 1 and 4 weeks of aging. Cell viability was determined by adenosin triphosphate (ATP) assay after DCT. The parameters evaluated for the antibiofilm property were total biovolume and percentage of green cells in E.faecalis biofilms. The data from the bioluminescence ATP assay as well as the total biovolume and green percentage were analyzed by non-parametric tests, Kruskal-Wallis for global comparison and Kolmogorov-Smirnov for each two variables. Results of the DCT and CLSM for all parameters evaluated show that the antimicrobial activity of AH Plus decreased over time, whereas GuttaFlow Bioseal had an opposite property, increasing its antibacterial activity as the material aged.

The purpose of this study was to test the antimicrobial activity and the smear layer removal of different irrigation protocols-sodium hypochlorite (NaOCl), NaOCl followed by ethylenediaminetetraacetic acid (EDTA), and NaOCl combined with etidronic acid (HEBP)-against infected dentine tubules during root canal preparation. Single rooted premolars contaminated with Enterococcus faecalis were chemomechanically prepared. Depending on the irrigation protocols, the roots were divided into the following groups: (1) distilled water during and after instrumentation; (2) 2.5% NaOCl during and after instrumentation; (3) 2.5% NaOCl/9% HEBP during and after instrumentation; and (4) 2.5% NaOCl during instrumentation followed by 17% EDTA after instrumentation. The percentage of dead cells and the biovolume in infected dentine tubules were measured using confocal laser scanning microscopy and the live/dead technique. Smear layer removal on root canal wall surfaces was observed by means of scanning electron microscopy. Results were compared through parametric tests (p < .05). The groups NaOCl, NaOCl/HEBP, and NaOCl+EDTA exerted the highest antimicrobial activity (p > .05), followed by the group irrigated with water. All the irrigation protocols-including water-significantly reduced the bacteria biovolume. No dentine tubules free of smear layer were found in the positive control or the 2.5% NaOCl group. With NaOCl/HEBP and NaOCl+EDTA, respectively, 90.41% ± 7.33 and 76.54% ± 15.30 of dentine tubules were free of smear layer (p = .01). NaOCl/HEBP and NaOCl+EDTA exerted an important antimicrobial activity against bacteria inside dentine tubules, lowering the bacteria biovolume and eliminating a high amount of the smear layer, particularly in the NaOCl/HEBP group., (© 2019 Wiley Periodicals, Inc.)

Aim: To determine the free available chlorine of 2.5% sodium hypochlorite (NaOCl) alone and combined with 9% etidronic acid (HEDP) in the presence of inhibitors, organic tissue and organic tissue plus dentine debris; to evaluate the influence of dentine debris on the tissue-dissolving capacity of both NaOCl solutions; and to determine the antimicrobial action of these solutions when in contact with organic tissue and organic tissue plus dentine debris., Methodology: The available chlorine of the solutions over time in the absence and presence of the inhibitors was measured using a titration method. The organic tissue dissolution by the solutions alone and in the presence of dentine powder was evaluated by weighing bovine tissue specimens before and after exposure to the solutions for 3 and 10 min. For the antimicrobial activity, biofilms of Enterococcus faecalis were exposed to the solutions for 3 min in the absence and presence of organic tissue and organic tissue + dentine debris. The biovolume and percentage of damaged membrane cells of the biofilm were measured by means of confocal microscopy and the live/dead technique. Nonparametric tests were used to determine statistical differences (P < 0.05)., Results: Both inhibitors consumed the free available chlorine of the solutions over time. The presence of dentine debris significantly reduced the tissue dissolution capacity of the NaOCl solutions (P < 0.05). The percentages of biovolume reduction were not affected by the presence of the inhibitors in the two NaOCl solutions, whereas the percentage of damaged membrane cells was significantly reduced (P < 0.001). Overall, a similar behaviour was observed in the NaOCl and NaOCl/HEDP groups., Conclusions: The presence of organic tissue and organic tissue + dentine debris favoured rapid consumption of the free chlorine of NaOCl and NaOCl/HEDP. This resulted in a decreased ability to dissolve organic tissue without affecting the short-term antimicrobial activity., (© 2018 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Objective: To evaluate the smear layer removal and wettability of AH Plus sealer on root canal dentin treated with MA (maleic acid), MA + CTR (cetrimide) and MA + CTR + CHX (chlorhexidine) as final irrigating regimens., Material and Methods: For smear layer removal, 40 teeth were instrumented to size F4 and divided into four groups: (1) 7% MA, (2) 7% MA + 0.2% CTR, (3) 7% MA + 0.2% CTR + 2% CHX, (4) distilled water (control). After irrigation, teeth were subjected to SEM analysis. For contact angle analysis, 20 teeth were split longitudinally and divided into four groups similar to smear layer analysis. AH plus sealer was placed on each specimen and contact angle was analysed., Results: In both smear layer (p = .393) and contact angle analysis (p = .961), there was no significant difference between the groups MA and MA + CTR. However, MA + CTR + CHX removed smear layer less effectively (p = .023) and increased the contact angle of the sealer (p = .005). In smear layer analysis, specimens in negative control group were heavily smeared. In case of contact angle analysis, samples in the control group had least contact angle., Conclusion: MA alone or in combination with CTR removed smear layer effectively and increased the wettability of AH plus sealer to root canal dentin.

Introduction: The aim of this study was to determine the antimicrobial activity of mixed alkaline tetrasodium EDTA (EDTANa 4 )/sodium hypochlorite (NaOCl) solutions with and without the addition of cetrimide (CTR) against Enterococcus faecalis biofilms., Methods: The antimicrobial solutions were evaluated on a 3-week biofilm of E. faecalis grown on radicular dentin blocks. The irrigating solutions were 2.5% NaOCl group, 20% EDTANa 4  group, 10% EDTANa 4 group, 2.5% NaOCl/10% EDTANa 4 group, 2.5% NaOCl/5% EDTANa 4 group, 2.5% NaOCl/10% EDTANa 4 /0.2% CTR group, 2.5% NaOCl/5% EDTANa 4 /0.2% CTR group, and 0.9% saline solution group. Cell viability was determined by adenosine triphosphate assay, and culture techniques were used to determine colony-forming unit (CFU) counts. In groups with positive growth, the Pearson linear correlation coefficient r (-1 ≤ r ≤ 1) between relative light units (RLUs) and log 10 (CFUs + 1) was calculated. The results of the bioluminescence adenosine triphosphate assay and CFUs of the groups were analyzed by means of analysis of variance and the Duncan test., Results: There was Pearson correlation between RLUs and log 10 (CFUs + 1). A similar reduction of RLUs in all NaOCl groups was seen, giving statistical differences with respect to the control. In the NaOCl groups there was no bacterial growth. The lowest antimicrobial efficacy was found for the EDTANa 4 groups., Conclusions: Mixed alkaline EDTANa 4 /NaOCl solutions with and without the addition of CTR do not interfere with the antimicrobial activity of NaOCl., (Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The aim of this study was to identify morphologic peculiarities of roots and analyze the root canal configuration in maxillary and mandibular first and second molars by means using cone-beam computed tomographic (CBCT) imaging in a Spanish population., Methods: A total of 284 maxillary molars and 242 mandibular molars from 112 patients were examined in vivo by CBCT imaging; only untreated molars with healthy and fully matured apices were included in this study. Details regarding the number of roots, number of canals, and root canal configuration were recorded., Results: Maxillary first and second molars had 3 roots in 97.2% and 79%, respectively. In mandibular molars, the frequency of 2 roots was 94% in first molars and 83% in second molars. The canal configuration of the palatal root was 100% Vertucci type I (1-1) in first and second molars. The distobuccal root showed a Vertucci type I configuration in 97% of first and 100% of maxillary second molars. The mesiobuccal root for first molars showed a Vertucci type II configuration (2-1) in 56.5% cases and Vertucci type IV (2-2) in 23.2%. For maxillary second molars, the Vertucci type I configuration reached 52.7%. In mandibular molars, the mesial root showed higher variability. Most frequent was the presence of 2 canals, Vertucci type II for first and second molars. In the distal root, the most common configuration was Vertucci type I in both molars., Conclusions: The greater percentage of fused roots was observed in maxillary molars. Vertucci type II configuration was more frequent than type IV in the mesial root of mandibular molars and the mesiobuccal root of maxillary molars. A third canal in the mesial root of first mandibular molars (6.7%) was higher than expected., (Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

The antibacterial efficacy of intracanal medicaments for 2 and 7 days, in open apex root canals contaminated with Enterococcus faecalis biofilms was compared. One hundred and thirty-eight standardized uniradicular human roots were inoculated with E. faecalis. Colony forming units (CFU) were recorded before and after medication. Samples were divided in two (2/7 days), and subdivided (n=8/group): triple antibiotic paste (TAP); double antibiotic paste (DAP); dental base paste (DBP), consisting of calcium hydroxide, propylene glycol and calcium carbonate; DBP+0.2% chlorhexidine (CHX); DBP+0.2% cetrimide (CTR); DBP+0.2% CHX+0.2% CTR; 2.5% sodium hypochlorite (NaOCl); and distilled water. At both periods TAP, DAP, DBP+0.2% CHX, DBP+0.2% CTR and DBP+0.2% CHX+0.2% CTR exhibited no growth (NG) of E. faecalis. Distilled water and 2.5% NaOCl obtained the lowest CFU reduction. No growth with DBP was reached only at 7 days. CHX and/or CTR pastes were as effective as DAP and TAP. A 2-day period provided an effective disinfection.

Aim: To evaluate the antibiofilm activity of 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), 2% alexidine (ALX) and 0.2% cetrimide (CTR) alone and in combination on mature polymicrobial root canal biofilms on human dentine using confocal laser scanning microscopy (CLSM)., Methodology: Twenty-eight human dentine specimens were infected for 21 days with microbial samples collected from infected root canals of three volunteers. Antibiofilm activity of the irrigating solutions was evaluated after 3 min of contact time under CLSM. For quantification purposes, bioimage&#95;L software was used. The variables evaluated were the log 10 of total biovolume (μm 3 ) and percentage of live cells (green) population. Statistical analysis of both variables was performed using an anova test and a post hoc Duncan test to determine significant clusters amongst groups. The variable green population percentage was previously subjected to the normalized Anscombe transformation., Results: The NaOCl group had a total biovolume and percentage of live cells significantly lower than the other groups (P ˂ 0.001). The addition of 0.2% CTR significantly increased the antimicrobial effect of 2% CHX (P ˂ 0.001). There were no significant differences between 0.2% CTR, 2% ALX and the combination of both (P ˂ 0.05)., Conclusions: Overall, 2.5% NaOCl dissolved and killed bacteria significantly more efficiently when used against polymicrobial mature biofilm on human dentine. Cetrimide improved the antimicrobial activity of chlorhexidine and alexidine., (© 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Introduction: The aim of this study was to evaluate the influence of the smear layer on the antimicrobial activity of a 2.5% sodium hypochlorite (NaOCl)/9% etidronic acid (HEBP) irrigating solution against bacteria growing inside dentin tubules., Methods: Dentin tubules were infected with Enterococcus faecalis by centrifugation. After 5 days of incubation, the smear layer had formed in half of the samples, which were then treated with 2.5% NaOCl either alone or combined with 9% HEBP for 3 minutes. The percentage of dead cells in infected dentinal tubules was measured using confocal laser scanning microscopy and the live/dead technique. The smear layer on the surface of the root canal wall was also observed by scanning electron microscopy. Results of the percentage of dead cells were compared using parametric tests after subjecting data to the normalized Anscombe transformation. The level of significance was P < .05., Results: In the absence of the smear layer, 2.5% NaOCl alone and combined with 9% HEBP showed high antimicrobial activity without significant differences between the 2. The smear layer reduced the antimicrobial activity of 2.5% NaOCl significantly, whereas the solution with HEBP was not affected. No dentin tubules free of the smear layer were obtained in the 2.5% NaOCl group. In the case of 2.5% NaOCl/9% HEBP, 95.40% ± 3.63% of dentin tubules were cleaned., Conclusions: The presence of the smear layer reduced the antimicrobial activity of 2.5% NaOCl. The combination of 2.5% NaOCl/9% HEBP exerted antimicrobial activity that was not reduced by the smear layer., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to determine the influence of dentin powder on the concentration, pH, and antimicrobial activity of sodium hypochlorite (NaOCl) alone and combined with etidronic acid (HEBP)., Methods: Biofilms of Enterococcus faecalis were grown on the surface of dentin blocks for 5 days and then exposed to 1% and 2.5% NaOCl alone or combined with 9% HEBP for 3 minutes in the absence and presence of dentin powder. The biovolumes of the biofilm were measured using confocal microscopy and the live/dead technique. The available chlorine and pH of the solutions were also measured. Nonparametric tests were used to determine statistical differences (P < .05)., Results: The presence of dentin powder resulted in a reduction of the free available chlorine and pH in all the irrigating solutions; 1% NaOCl lost its antimicrobial activity completely in the presence of dentin powder. The antimicrobial activity was significantly reduced in the 2.5% NaOCl and 1% NaOCl/HEBP groups, and it was not affected in the 2.5% NaOCl/HEBP group., Conclusions: The presence of dentin powder significantly decreased the available chlorine and antimicrobial activity of 1% NaOCl, 2.5% NaOCl, and 1% NaOCl/HEBP irrigating solutions. The antimicrobial activity of 2.5% NaOCl/HEBP was not affected by the dentin powder after a 3-minute contact time against E. faecalis biofilms., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aim: To evaluate the antimicrobial effect of 2.5% sodium hypochlorite alone (NaOCl) and associated with 9% HEBP (NaOCl/HEBP), 2% peracetic acid (PAA) and 2% chlorhexidine (CHX), on the viability of Enterococcus faecalis biofilms attached to dentine., Methodology: Biofilms of E. faecalis were grown on the surface of dentine blocks for 5 days and then exposed to the irrigating solutions for 3 min. Distilled water was used as the control. The total biovolume and the percentage of dead cells of the infected dentine were measured by means of confocal microscopy and the live/dead technique. Nonparametric tests were used to determine statistical differences (P < 0.05)., Results: NaOCl and the NaOCl/HEBP mixture were associated with a significantly greater percentage of dead cells, followed by PAA (P < 0.05). No significant antimicrobial effect of CHX was observed in comparison with the control group. Total biovolume decreased significantly in NaOCl, NaOCl/HEBP and PAA solutions in comparison with the CHX and control groups., Conclusions: NaOCl alone or associated with HEBP were the most effective irrigant solutions in dissolving and killing E. faecalis biofilms., (© 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Objectives: The aim of this study was to determine the antimicrobial and antibiofilm activities and physicochemical properties of AH Plus sealer mixed with different concentrations of benzalkonium chloride (BC)., Methods: AH Plus was tested alone and mixed with 1%, 2% and 3% of BC. The antimicrobial and antibiofilm activities of the sealers against Enterococcus faecalis were evaluated by the direct contact test (DCT) and by confocal laser scanning microscopy, respectively. Setting time, flow and solubility were assessed according to ANSI/ADA specifications. Microhardness and contact angle tests were also performed. The chemical changes of the sealers were evaluated by X-ray diffraction analysis, and both Fourier transform infrared spectroscopy (FT-IR) and attenuated total reflectance Fourier transform infrared (ATR FT-IR)., Results: AH Plus+3% BC was the only sealer to promote total elimination of E. faecalis and the biovolume in this group was significantly lower than in the rest of the sealers (p>0.05). The physical properties of the sealers were according to the ANSI/ADA specifications. The microhardness decreased significantly when BC was added and a significant reduction in contact angle was obtained when incorporating 2% and 3% BC (p<0.05). No phase changes were observed with the modified sealers., Conclusions: The addition of 2% or higher concentrations BC to AH Plus showed antimicrobial and antibiofilm activities without affecting the properties specified in ANSI/ADA standards. However, additives to the root canal sealer altered other physical and chemical properties that are not commonly found in the literature to evaluate filling materials., Clinical Significance: The present study highlights that the antimicrobial properties of AH Plus can be significantly improved with the addition of BC. Testing beyond what is specified in standards may be indicated., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: The success of endodontic treatment depends largely on the control of microorganisms present in infected root canals. The aim of this study was to determine the residual antimicrobial activity of several final irrigation protocols with 7% maleic acid (MA) alone and combined with chlorhexidine (CHX), cetrimide (CTR) or both, in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown in uniradicular roots for 4 weeks. A total of 72 specimens were divided into 5 experimental groups according to the final irrigation regime used: Group 1: 2.5% NaOCl; Group 2: 7% MA; Group 3: 7% MA + 0.2% CTR; Group 4: 7% MA + 2% CHX; Group 5: 7% MA + 0.2% CTR + 2% CHX; and, Control Group: 0.9% saline solution. Twelve roots (2/group) that were instrumented and not infected served as negative or sterility controls. The proportion of ungrown samples over 60 days was evaluated using non-parametric Kaplan-Meier survival analysis. Differences among groups were tested using the log-rank test (p< 0.05)., Results: The association of MA with CHX and CHX + CTR as final irrigating solutions showed the best results, 5 and 4 samples out of 12, respectively, and without differences between them (p = 0.928), followed by 7% MA + 0.2% CTR with 7 out of 12. The 7% MA (11/12) group showed significant differences with respect to the groups in which MA was combined with CHX (p < 0.005) and CHX + CTR (p < 0.005)., Conclusion: Final irrigating solutions of 7% MA combined with 2% CHX or 2% CHX + 0.2% CTR were found to effectively improve antimicrobial root canal disinfection.

Introduction: The aim of this study was to evaluate the antimicrobial activity of a 2.5% sodium hypochlorite (NaOCl)/9% etidronic acid (HEBP) irrigant solution on Enterococcus faecalis growing in biofilms and a dentinal tubule infection model., Methods: The antimicrobial activity of the solutions 2.5% NaOCl and 9% HEBP alone and associated was evaluated on E. faecalis biofilms grown in the Calgary biofilm model (minimum biofilm eradication concentration high-throughput device). For the dentinal tubule infection test, the percentage of dead cells in E. faecalis-infected dentinal tubules treated with the solutions for 10 minutes was measured using confocal laser scanning microscopy and the live/dead technique. Available chlorine and pH of the solutions were also measured. Distilled water was used as the control. Nonparametric tests were used to determine statistical differences., Results: The highest viability was found in the distilled water group and the lowest in the NaOCl-treated dentin (P < .05). Both NaOCl solutions killed 100% of the E. faecalis biofilms and showed the highest antimicrobial activity inside dentinal tubules, without statistical differences between the 2 (P < .05). The HEBP isolated solution killed bacteria inside dentinal tubules but did not present any significant effect against E. faecalis biofilms. The incorporation of HEBP to NaOCl did not cause any loss of available chlorine within 60 minutes., Conclusions: HEBP did not interfere with the ability of NaOCl to kill E. faecalis grown in biofilms and inside dentinal tubules., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to compare the efficacy of different dentine adhesives in delaying the coronal bacterial leakage of Enterococcus faecalis in filled root canals. Materials and methods. Ninety-five lower incisors of patients >65 years of age were instrumented using the ProTaper system and were irrigated with 1 mL of 2.5% sodium hypochlorite (NaOCl) alternated with 1 mL 17% EDTA between each file change. Final irrigation was performed with 5 mL of 17% EDTA and then flushed with 5 mL of distilled water. The teeth were randomly divided into five experimental groups (n = 15/group) and one of the following dentine adhesives was applied: (1) AdheSE; (2) Excite DSC; (3) Clearfil Protect Bond; (4) One Coat 7.0; or (5) Control group without adhesive. After filling the root canals, the samples were mounted on a double chamber device to evaluate the bacterial filtration of E. faecalis during a period of 240 days. The results underwent non-parametric Kaplan-Meier survival analysis and comparisons among groups were done using the Log-Rank test., Results: At 240 days, E. faecalis was detected in samples of all groups in the lower chamber. The highest survival value was obtained by One Coat 7.0, giving statistically significant differences from the other groups, whereas Clearfil Protect Bond, AdheSE and Excite DSC showed similar behaviours, likewise similar to the Control group., Conclusions: One Coat 7.0 adhesive system provides the longest survival value to delay E. faecalis coronal leakage in filled root canals.

Background: The use of antimicrobial solutions has been recommended to disinfect demineralized dentin prior to placing the filling material. The aim of this study was to evaluate the ability of several antimicrobials in controlling Streptococcus mutans (SM) biofilm formed in dentin., Methods: Antimicrobial activity of 0.2% and 2% chlorhexidine (CHX), 0.2% cetrimide (CTR) and 0.2%, 0.5%, 1% and 2% alexidine (ALX) was assayed on 1-week SM biofilm formed on standardized coronal dentin blocks. Results of SM biofilm antimicrobial activity by different protocols were expressed as the kill percentage of biofilm and the term "eradication" was used to denote the kill of 100% of the bacterial population. To compare the efficacies of the different protocols the Student t test was used, previously subjecting data to the Anscombe transformation., Results: All ALX concentrations tested and 0.2% CTR achieved a kill percentage higher than 99%, followed by 2% CHX with percentages above 96% (no statistically significant difference among them). Whereas 2% ALX and 0.2% CTR respectively showed eradication in 10 and 9 of the twelve specimens, 0.2% CHX did not produce eradication in any case., Conclusions: The present study shows that, when used for one minute, 2% and 1% alexidine, and 0.2% cetrimide, achieve eradication of Streptococcus mutans biofilm in most specimens when applied to a dentin-volumetric model.

Introduction: The use of root canal filling materials with antibacterial activity can be considered beneficial to reduce the remaining microorganisms in the root canal system, where Enterococcus faecalis is often found, and prevent recurrent infection. The aim of this study was to evaluate the antimicrobial activity and capacity for inhibiting E. faecalis biofilm formation of AH Plus, alone and mixed with chlorhexidine (CHX), cetrimide (CTR), and combinations of the two., Methods: AH Plus alone and mixed with 1% and 2% CHX, 0.1%-0.5% CTR, and combinations of both were tested to assess antimicrobial activity by a modified direct contact test and determine inhibition of E. faecalis biofilm formation at 24 hours. The results were expressed as log10 viable counts. Eradication and inhibition of biofilm formation were understood as no bacterial growth or log10 reduction = 5 with respect to the control (AH Plus alone)., Results: AH Plus + CHX showed a low antimicrobial activity with respect to the control (at 2%, log10 reduction = 1.30). None of the tested concentrations achieved eradication or inhibition of biofilm. AH Plus + CTR showed a direct relationship of concentration-antimicrobial effect, reaching a log10 reduction of 2.92 at 0.5% and inhibition of biofilm formation at 0.2%. With the combination CHX + CTR, lower concentrations were needed for the same effect, and eradication and inhibition of biofilm were achieved., Conclusions: The addition of CHX, CTR, or some combination of both to AH Plus confers it with bactericidal and anti-biofilm activity against E. faecalis., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aim: To compare the chemomechanical reduction and regrowth of Enterococcus faecalis between rotary and reciprocating systems in root canal preparation., Methodology: Seventy-six single-rooted human mandibular premolars were selected and standardized to 15 mm in length. Root canals were enlarged up to a size 25 K-file and irrigated with distilled water and then were infected with E. faecalis for 4 weeks. The specimens were divided into 3 groups (n = 24) for instrumentation with Mtwo, Twisted File and WaveOne. Each group was further divided into two subgroups (n = 12) according to the irrigant used: distilled water or 5.25% sodium hypochlorite (NaOCl). Before and after rotary preparation, microbiological samples were collected using three sterilized paper points, and efficacy was expressed as reduction in percentage. The proportion of grown samples for 60 days was evaluated using nonparametric Kaplan-Meier survival analysis. Differences amongst groups were tested using the log-rank test at a significance level of 0.05., Results: In the main root canal, the percentage reduction in the distilled water and 5.25% NaOCl groups ranged from 95.9% to 100%, with no significant differences amongst the three systems (P > 0.05). The bacterial regrowth in NaOCl groups revealed that Mtwo had the lowest number of samples regrown at 60 days, giving statistically significant differences with respect to Twisted File (P = 0.029) and WaveOne (P = 0.005)., Conclusions: Reciprocating and rotary systems resulted in similar percentage reduction in E. faecalis when using either distilled water or 5.25% NaOCl solution. Over time, the Mtwo system was more effective regarding disinfection., (© 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Introduction: The use of root canal filling materials with antibacterial activity could be considered beneficial to reduce any remaining microorganisms and prevent recurrent infection. The aim of this study was to evaluate the physical properties of AH Plus (Dentsply DeTrey, Konstanz, Germany) alone and mixed with 1% or 2% chlorhexidine (CHX); 0.1%, 0.2%, 0.3%, and 0.5% of cetrimide (CTR); and combinations of both., Methods: Setting time, flow, solubility, and radiopacity of AH Plus and modified AH Plus were evaluated following the American National Standards Institute/American Dental Association's requirements (ANSI/ADA Specification No. 57/2000). Five samples of each material were tested for each property. The hypothesis of equality among groups was rejected by an analysis of variance test, and then a post hoc Tukey test was performed., Results: AH Plus and modified AH Plus gave values that are within the required standards. Overall, results indicate that CTR increased setting time, but CHX alone and CHX + CTR reduced it. CHX increased the flow, whereas CTR reduced it, and their combinations gave intermediate values comparable with those of AH Plus. Concerning solubility, the weight loss in all samples was under the 3% limit set by the ANSI/ADA. In comparison with AH Plus alone, radiopacity gave slightly lower values with CHX, higher values with CTR, and similar values with combinations., Conclusions: The addition of CHX, CTR, and combinations of both to AH Plus did not alter the physical properties specified by ANSI/ADA requirements., (Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The use of irrigating solutions with long-lived activity helps to avoid failure of endodontic therapy. The aim of the present study was to evaluate and compare the antimicrobial substantivity against Enterococcus faecalis by using as carrier a dentin-volumetric unit exposed to chlorhexidine (CHX) and alexidine (ALX)., Methods: Standardized dentin blocks of human molars were treated for 1 minute with 0.5% CHX, 2% CHX, 1% ALX, and 2% ALX. They were exposed to E. faecalis in suspension to determine antimicrobial substantivity during a period of 80 days. Results were analyzed by means of Kaplan-Meier survival analysis (P < .05)., Results: ALX obtained the best results, with differences that were significantly different from CHX regardless of the concentration. Although all the samples treated with CHX were contaminated at the end of the study period, a direct relationship was seen between concentration and survival time. There was no statistically significant difference between 2% and 1% ALX., Conclusions: The present study shows that 2% and 1% ALX used for 1 minute provide longer antimicrobial substantivity against E. faecalis than CHX when applied to 2% and 0.5%., (Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)