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Scanning electron microscope images of the negative control. (a) The dentin surface and the dentinal tubules were covered by pulp tissue; (b) Collagen fibers were seen inside the dentinal tubules.

Scanning electron microscope images of the negative control. (a) The dentin surface and the dentinal tubules were covered by pulp tissue; (b) Collagen fibers were seen inside the dentinal tubules.

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Objectives This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth. Materials and Methods Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative co...

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... negative control specimens showed the normal appearance of open dentinal tubules, dentin structure, pulp tissue and collagen fibers (Figure 2). No microorganisms were seen in the canal walls. ...

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Citations

... faecalis has been observed to have penetrated up to 1000 µm. (34,35) For evaluation of penetration depth of root canal irrigants, several methods like Dye bleaching, Radiographic visualization, SEM, Gates Glidden drills and CLSM have been employed by various authors as found in literature. (29,(36)(37)(38) However, amongst all these methods, CLSM has the advantages like ease in sample processing and preparation which tends to produce smaller number of artefacts. ...
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Introduction: The aim of this study was to evaluate the antibacterial efficacy of Vitex negundo Linn. extract as root canal irrigant against Enterococcus faecalis and its penetration into root dentin. Methods and Materials: Forty single rooted premolars were randomly divided into 4 groups: 3% Sodium hypochlorite (NaOCl), 2% Chlorhexidine (CHX) , 100mg/ml Vitex negundo Linn. and saline as control all mixed with Rhodamine B dye. Test samples were analysed for bacterial count before and after irrigation using absorbent paper points and the colony forming units were recorded and measured. Sectioning of the samples was performed at three levels 3mm,6mm,9mm from apex and then these samples were analysed using confocal laser scanning microscopy for penetration depth of the irrigant within the dentinal tubules. Paired t-test and ANOVA test were used to perform statistical analysis with level of significance set at 0.05 Results: The mean CFU/ml count of Enterococcus facealis reduced significantly in all the groups post irrigation. All the irrigants showed maximum penetration depth at coronal third level compared to middle and apical third level respectively. The penetration depth of NaOCl group was better when compared to CHX group and Vitex negundo Linn. group but the difference was statistically not significant. Conclusion: Although 3% NaOCl was the most effective irrigant, all agents exerted acceptable antimicrobial activity against Enterococcus faecalis and penetration depth within tubules of dentin.
... In group M, the difference between the CFU in dentinal chips and the CFU in the canal lumen was statistically significant when using 6.25 mg/mL and nonsignificant with 12.5 mg/mL against S1, while the difference was statistically nonsignificant for both concentrations against S2 and S3. This is justified by the fact that EF colonizes the dentinal walls adhering to the mineral part, probably through LTA (lipoteichoic acids), and to the collagen through AS (aggregation substance) and other surface adhesins [100]; moreover, it has the ability to penetrate the dentinal tubules deeply because of their small size, which is enough for the bacteria to efficiently penetrate the tubules and live within them, in addition to the fact that they can tolerate periods of starvation [71,101]. Furthermore, Portenier et al. [102] demonstrated that the dentin itself can sometimes antagonize the bactericidal activity of the medicament. ...
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Background and Objectives. Multiple antibacterial agents have been mixed and used as an intracanal medicament-like modified triple antibiotic paste (MTAP) to eliminate Enterococcus faecalis (EF), which has been most frequently identified in the cases of failed root canal treatment and periapical lesions. This study is aimed at using a single antibacterial agent, nitrofurantoin (Nit), as an experimental intracanal medicament paste against different clinical isolates of EF), which has been most frequently identified in the cases of failed root canal treatment and periapical lesions. This study is aimed at using a single antibacterial agent, nitrofurantoin (Nit), as an experimental intracanal medicament paste against different clinical isolates of Materials and Methods. Three strains of EF), which has been most frequently identified in the cases of failed root canal treatment and periapical lesions. This study is aimed at using a single antibacterial agent, nitrofurantoin (Nit), as an experimental intracanal medicament paste against different clinical isolates of n = 90), group M (MTAP) (n = 90), group M (MTAP) (n = 90), group M (MTAP) (EF), which has been most frequently identified in the cases of failed root canal treatment and periapical lesions. This study is aimed at using a single antibacterial agent, nitrofurantoin (Nit), as an experimental intracanal medicament paste against different clinical isolates of n = 90), group M (MTAP) (n = 90), group M (MTAP) (n = 90), group M (MTAP) (EF), which has been most frequently identified in the cases of failed root canal treatment and periapical lesions. This study is aimed at using a single antibacterial agent, nitrofurantoin (Nit), as an experimental intracanal medicament paste against different clinical isolates of. Results: Nit could eradicate S1, S2, and S3 completely with concentrations of 6.25, 12.5, and 25 mg/mL, respectively, while MTAP showed complete eradication of the three strains only at 25 mg/mL. In all the groups, it was found that the CFU counts of EF), which has been most frequently identified in the cases of failed root canal treatment and periapical lesions. This study is aimed at using a single antibacterial agent, nitrofurantoin (Nit), as an experimental intracanal medicament paste against different clinical isolates of. Conclusion: At the concentration of 25 mg/mL, the Nit paste is effective in eradicating EF completely when it is used as an intracanal medicament.EF), which has been most frequently identified in the cases of failed root canal treatment and periapical lesions. This study is aimed at using a single antibacterial agent, nitrofurantoin (Nit), as an experimental intracanal medicament paste against different clinical isolates of.
... [2] However, after conventional root canal preparation, microorganisms may remain either within the dentinal tubules or bound within the apical dentin plug. [3] One of the leading causes of root canal therapy failure is the persistence of microorganisms and their reinfection. Engstrom et al. recovered numerous species of bacteria from failed root canal cases. ...
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... [1] However, microorganisms may remain after conventional canal preparation, either within the dentinal tubules or bound within the apical dentin plug. [2] One of the main causes of root canal therapy failure is the persistence of microorganisms and their reinfection. Sundqvist et al. recovered numerous species of bacteria from failed root canal cases; of which Enterococcus faecalis was found to be the most prevalent bacteria. ...
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Background: Endodontic infections require effective removal of microorganisms from the root canal system for long-term prognosis. Sodium hypochlorite (NaOCl) is the most effective irrigant currently, but potential complications due to its toxicity warrant search for newer alternatives. In this study, the antimicrobial efficacy of Morinda citrifolia (MC), green tea polyphenols and Triphala was compared with 5% NaOCl against Enterococcus faecalis. Materials and Methods: In this in vitro study sixty extracted human premolar teeth were infected with E. faecalis, a Group D Streptococci for 48 h. At the end of 48 h, the vital bacterial population was assessed by counting the number of colony-forming units (CFUs) on blood agar plate. Samples were divided into five groups; Group I (distilled water), Group II (NaOCl), Group III (MC), Group IV (Triphala), and Group V (green tea polyphenols). The samples were irrigated with individual test agents and CFUs were recorded. Kruskal–Wallis test was performed as the parametric test to compare different groups. Student's t-test was used to compare mean values between groups before and after treatment with test agents (P < 0.001). Results: NaOCl was the most effective irrigant the elimination of E. faecalis reinforcing its role as the best irrigant available currently and a gold standard for comparison of the experimental groups. Its antibacterial effect was comparable to Triphala. Among the experimental groups, MC showed the minimum antibacterial effect. Conclusion: The use of herbal alternatives as a root canal irrigant might prove to be advantageous considering the several undesirable characteristics of NaOCl.
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The cross-infections may occur during handling of dental elements, affecting the health of dental practitioners and researchers. This study aimed to analyze the influence of the storage medium temperature on the bacterial contingent of the human teeth used for research purposes. Thirty human teeth were donated to the Human Teeth Biobank immediately after extraction. The teeth were cleaned with tap water and neutral soap. The teeth were randomly distributed according to the temperature of the storage solution (deionized water): at 4 °C (refrigerator) or at −10 °C (freezer) and were stored individually in sterile vials during 60 days. After this period, a microbiological analysis (CFU/mL) of the storage solutions was performed and teeth were submitted to SEM analysis. Data were analyzed by Kruskal–Wallis test followed by Dunn's post-test (p ≤ .05). Total aerobic bacteria ranged from 5.8 to 8.4 log10 CFU/mL for refrigerated solution and from 1.9 to 8.5 log10 CFU/mL for frozen solution. No statistical differences were found between the storage solutions (p > .05). The counts of Streptococcus spp., Lactobacillus spp., and Staphylococcus spp. were similar for both storage solutions (p > .05). SEM analysis showed spiral- and rod-shaped bacteria attached on teeth stored under 4 °C, which may suggest the presence of Treponema spp. and Lactobacillus spp. Similar morphological forms were found on teeth stored under −10 °C. A biofilm organized in honeycomb-like form was found in the frozen teeth. Cocci were eventually found in all the samples. It was concluded that bacterial growth and survival were not influenced by the temperature of the teeth storage solution.
... 13,14 It has been suggested that the dentinal tubule microflora associated with a periodontal pocket could act as a reservoir for recolonization of the pocket after debridement. 13,14 Numerous studies have been done to review bacterial invasion through dentinal tubules from the pulp space [15][16][17][18] but there is less literature on bacterial penetration through cementum. ...
... Significant differences could only rarely be noticed. [4,9,99]. Um die Spülwirkung zu verbessern, kann die Spülflüssigkeit mittels Schall-oder Ultraschallinstrumenten aktiviert werden [21,41] ...
Thesis
Hintergrund und Ziele: Da im Rahmen einer endodontischen Behandlung selbst die kombiniert chemomechanische Aufbereitung keine absolute Keimfreiheit im Wurzelkanalsystem erzielen kann, wird zur weiteren Reduktion der Mikro-organismen bei apikalen Parodontitiden der lokale Einsatz von Medikamenten empfohlen. Ziel dieser Arbeit war es, die Penetrationstiefen unterschiedlicher medikamentöser Wurzelkanaleinlagen in die Dentintubuli und die penetrierten Flächen im Wurzelquerschnitt zu untersuchen. Material und Methode: Von 66 extrahierten, menschlichen, einwurzeligen, kariesfreien Unterkiefer-frontzähnen wurde die Zahnkrone abgetrennt. Ein geeignetes Spülprotokoll konnte mittels Gefrierbruchverfahren und Untersuchung mit dem Raster-elektronen-mikroskop bestimmt werden: Während der Aufbereitung erfolgte die Wechselspülung mit Natriumhypochlorit (NaOCl) und Zitronensäure mit jeweils 1 ml für 20 s. Die Abschlussspülung setzte sich zusammen aus 1 ml Zitronensäure für 20 s, drei Mal 1 ml NaOCl für 20 s mit anschließender Schallaktivierung für 10 s mit EddyTM und einer abschließenden Spülung mit 3 ml Ethanol für 30 s. Es erfolgte die Aufbereitung der Kanäle mit VDW.Gold® Reciproc® bis 1 mm vor Apex auf die Größe R50. Nach Trocknung der Wurzelkanäle wurden die Probenkörper in drei Gruppen (n=20) eingeteilt. Die untersuchten Medikamente AH TempTM, Ledermix® und Chlorhexamed® Gel wurden mit einer Rhodamin B Lösung angefärbt und in die Kanäle appliziert. Um eine Überstrahlung im konfokalen Laser-Scanning Mikroskop (CLSM) zu vermeiden, wurde zusätzlich eine R50 Guttaperchaspitze in den Kanal eingebracht. Nach einer Lagerung für 24 h konnten die koronalen und apikalen Wurzeldrittel in Technovit® 4071 eingebettet werden. Unter dem CLSM wurden die Penetrationstiefen der Medikamente in die Dentintubuli und die gefärbten Flächen im Wurzelquerschnitt ausgemessen. Als Negativkontrolle dienten drei Zähne mit den Medikamenten ohne Anfärbung und als Positivkontrolle wurden drei Zähne mit Rhodamin B Lösung auf Wasserbasis versehen. Die statistische Auswertung erfolgte mit dem Programm IBM SPSS® für Windows, Version 21. Ergebnisse und Beobachtungen: Für alle drei Medikamente konnte eine Penetration in die Dentintubuli festgestellt werden. Unabhängig vom jeweiligen Medikament war koronal tendenziell eine tiefere Penetration bzw. eine größere penetrierte Dentin-fläche zu beobachten als apikal. Bei der Auswertung der relativen Penetrationstiefe und gefärbten Fläche ergab sich zwischen den drei Präparaten und ihren jeweiligen koronalen und apikalen Werten kein signifikanter Unterschied. Die absolute Penetration von AH TempTM war im koronalen Bereich signifikant tiefer als apikal und übertraf auch die Penetrationstiefen von Ledermix® und Chlorhexamed®. Die absolute penetrierte Fläche zeigte sich für AH TempTM und Chlorhexamed® koronal signifikant größer als apikal. Das Penetrationsmuster war unabhängig vom untersuchten Medikament sehr variabel. Zwischen dem Wurzelabschnitt und dem Verteilungsmuster ließ sich keine Korrelation feststellen. Schlussfolgerung: Zwischen den Medikamenten zeigten sich Unterschiede bezüglich ihrer Penetrationstiefe bzw. der penetrierten Fläche. Zudem war eine Abhängigkeit von der Lokalisation innerhalb des Wurzelkanals zu erkennen. Tendenziell drang AH TempTM tiefer in die Dentintubuli ein als die Medikamente im Vergleich. Signifikante Unterschiede waren nur vereinzelt zu erkennen.
... Lasers when used for root canal disinfection are suggested to more effectively reduce bacteria located deep in the dentin than chemo-mechanical methods [51,52]. E. faecalis is usually viable at high pH levels and is capable of invading dentinal tubules and surviving as a single species, where it adheres to collagen in the presence of human serum [53][54][55]. Furthermore, it penetrates deeply in dentinal tubules, up to 400 μm in vitro [53]. ...
... Furthermore, it penetrates deeply in dentinal tubules, up to 400 μm in vitro [53]. The eradication of this bacterium in the distant areas of the tubular root canal system is a major challenge in treatment regimens and is crucial for the long term preservation of endodontically treated teeth [55]. The use of lasers like low-power diode laser associated with optical fiber in endodontics is an innovative approach for disinfection, providing access to formerly unreachable parts of the tubular network, due to their ability to penetrate dental tissues better than irrigant solutions [17,18,20,56,57]. ...
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Introduction Enterococcus faecium has become an important microorganism in nosocomial infections with great ability to acquire antibiotic resistance. However, little is known about their presence on the oral cavity. Therefore, our objective was to verify the presence of E. faecium and E. faecalis in endodontic infections and compare their susceptibility to conventional antibiotics and photodynamic therapy. Methods We performed 38 collections from the root canals of different patients. Positive Enterococcus agar samples were submitted to phenotypic and genotypic testing for species-specific confirmation. The isolates identified as E. faecium and E. faecalis were tested for susceptibility to antibiotics by the E-test method. After that, the isolates were evaluated for susceptibility to photodynamic therapy (PDT) using methylene blue and gallium arsenide aluminum laser with a wavelength of 660 nm and fluence of 39.5 J/cm² (energy of 15 J and time of 428 s). Results Cultures positive for E. faecalis were found in 22 patients (58%). Among these patients, only two had E. faecium in mixed infections with E. faecalis. In the isolates of E. faecalis, 27% were resistant to antibiotics, including tetracycline, ciprofloxacin, and azithromycin. The isolates of E. faecium showed no resistance to the antibiotics tested. Both the isolates of E. faecium and E. faecalis exhibit significant susceptibility to PDT, including the isolates resistant to antibiotics. The reductions achieved by PDT ranged of 2.76 to 4.31 log10 for E. faecalis strains and of 3.93 to 4.33 log10 for E. faecium strains. Conclusion E. faecium showed lower prevalence in endodontic infections and higher susceptibility to antibiotics when compared to E. faecalis. In in vitro assays, PDT had a significant antimicrobial activity for both strains.
... Although the filling material should provide an adequate seal, the long-term success of root canal treatment is also directly related to the restoration of the crown (Gillen et al. 2011). Core-filling materials can be exposed in the mouth due to caries, trauma and fracture of temporary or permanent restorations (Al-Nazhan et al. 2014, Oliveira et al. 2016). In addition, there is a delay in the time between the completion of root canal treatment and the placement of the permanent restoration (Balto 2011, Gillen et al. 2011. ...
... This degradation is directly related to the solubility of the materials. The more intense the adhesive interface dissolution (Marin-Bauza et al. 2012, Zhou et al. 2013, the greater will be the penetration of bacterial fluids, which might compromise the sealing of root canal walls (S€ onmez et al. 2012, Al-Nazhan et al. 2014. Besides, saliva contains a variety of enzymes responsible for sealer degradation (Roth et al. 2012, Li et al. 2014. ...
Article
Aim: To evaluate the wear of root wall surfaces, the bond strength of sealers to dentine and the demineralization around filling material after the canals were exposed to acid challenge. Methodology: Eighty-seven roots of mandibular incisors were selected. Thirty-two were used in the bond strength in vitro study (n=8) and 55 in the in situ study (n=11). Root canals were prepared biomechanically and then filled with gutta-percha and AH Plus, MTA Fillapex, Sealapex or Endofill. For 14 days, 11 participants used intraoral devices with 5 sterilized roots (4 experimental and 1 control - only canal prepared). Drops of sucrose were dripped onto roots allowing the accumulation of biofilm on canal surfaces. Roots were removed, sectioned and analysed for: bond strength of filling material using a push-out test and also wear profile and dentine demineralization using confocal microscopy. Bond strength (MPa) was evaluated by two-way ANOVA and Tukey test (α=0.05) and wear profile was assessed by Kruskal-Wallis and t-tests (α=0.05). Results: AH Plus had the highest bond strength values. Intermediate results were found in roots with MTA Fillapex and Endofill, whilst Sealapex had inferior results (P <0.05). No significant differences were found among root thirds (P >0.05). For wear profile, samples had degradation of the filling materials after exposure to the oral environment (P <0.05). Roots had signs of demineralization around the filling material when Sealapex and Endofill were used. Conclusions: Sealers were not able to prevent degradation of the adhesive interface and dentine. AH Plus and MTA Fillapex had superior bond strength to dentine and less intense demineralization around the root filling. This article is protected by copyright. All rights reserved.
... Accordingly, a conceptual shift, rather than incremental technical improvements based on the existing endodontic philosophy, is necessary to improve endodontic success rates and further promote the longevity of natural teeth. Despite technology improvements, current endodontic therapy is based on the concept that disinfected root canals should be sealed with as little residual space as possible to minimize bacterial recolonization (9,10). This concept was developed and improved over multiple decades before regenerative endodontic therapy was conceived. ...
Article
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The goal of endodontics is to save teeth. Since inception, endodontic treatments are performed to obturate disinfected root canals with inert materials such as gutta-percha. Although teeth can be saved after successful endodontic treatments, they are devitalized and therefore susceptible to reinfections and fractures. The American Association of Endodontists (AAE) has made a tremendous effort to revitalize disinfected immature permanent teeth in children and adolescents with diagnoses including pulp necrosis or apical periodontitis. The American Dental Association (ADA) in 2011 issued several clinical codes for regenerative endodontic procedures or apical revascularization in necrotic immature permanent teeth in children and adolescents. These AAE and ADA initiatives have stimulated robust interest in devising a multitude of tissue engineering approaches for dental pulp and dentin regeneration. Can the concept of regenerative endodontics be extended to revitalize mature permanent teeth with diagnoses including irreversible pulpitis and/or pulp necrosis in adults? The present article was written not only to summarize emerging findings to revitalize mature permanent teeth in adult patients but also to identify challenges and strategies that focus on realizing the goal of regenerative endodontics in adults. We further present clinical cases and describe the biological basis of potential regenerative endodontic procedures in adults. This article explores the frequently asked question if regenerative endodontic therapies should be developed for dental pulp and/or dentin regeneration in adults, who consist of the great majority of endodontic patients.