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Microbiological Analysis Of Teeth with Failed Endodontic Treatment And The outcome Of Conservative Retreatment
Abstract
The purposes of this study were to determine what microbial flora were present in teeth after failed root canal therapy and to establish the outcome of conservative re-treatment.
Fifty-four root-filled teeth with persisting periapical lesions were selected for re-treatment. After removal of the root filling, canals were sampled by means of advanced microbiologic techniques. The teeth were then re-treated and followed for up to 5 years.
The microbial flora was mainly single species of predominantly gram-positive organisms. The isolates most commonly recovered were bacteria of the species Enterococcus faecalis. The overall success rate of re-treatment was 74%.
The microbial flora in canals after failed endodontic therapy differed markedly from the flora in untreated teeth. Infection at the time of root filling and size of the periapical lesion were factors that had a negative influence on the prognosis. Three of four endodontic failures were successfully managed by re-treatment.
... Enterococcus faecalis, gram-positive coccus, is more resistant to instrumentation and to antiseptic agents, indicating that it can be estimated to persist more commonly in the root canal after poor root-canal preparation and obscuration [8,9]. Enteroccocus faecalis has the ability to survive in an environment with little available nutrients and it can remain without the synergistic support of another bacterium [10]. Therefore, persisting microorganisms or their products can remain in infectious process and basis treatment failure [10,11]. ...
... Enteroccocus faecalis has the ability to survive in an environment with little available nutrients and it can remain without the synergistic support of another bacterium [10]. Therefore, persisting microorganisms or their products can remain in infectious process and basis treatment failure [10,11]. Channel detergents are constantly changing and evolving for better performance. ...
Introduction: The main goal of root canal treatment is removing or reducing bacteria from root canal system and to this purpose, different materials and methods have been evaluated. Aim: The aim of this study was to evaluate the antibacterial effect of Pistacia atlantica resin on Enterococcus faecalis bacteria in vitro. Materials and Methods: In this experimental study, collected resin of Pistacia atlantica was extracted with Clevenger apparatus. Then, to determine the concentration of growth decreasing and growth inhibition on Enterococcus faecalis bacteria, concentration of 40% of essential oil was affected in ELISA plate. After 24 hours of incubation, the opacity of the walls, which indicates the growth rate of the bacteria, was read by an ELISA reader at 640 nm. Result: The results of this study showed that there is a significant difference in the mean of Opacity between different concentrations of Pistacia atlantica resin (P<0.001). So that concentrations of 40 and 20% caused complete growth inhibition and other concentrations caused a significant decrease in growth. Also, there is no difference between the inhibitory growth rate of the extract and the different concentrations of sodium hypochlorite and chlorhexidine (P=0.4). Conclusion: From the findings of this study, it can be concluded that extract of Pistacia atlantica has a significant growth inhibition effect at high concentrations and decreasing growth effect in lower concentrations on Enterococcus faecalis.
... Iatrogenic events such as ledging may also prevent cleaning of the root canal system beyond the ledge if it precludes physical access. Furthermore, introduction of Deep periodontal pockets Trauma microbes via caries or exposed dentine, cracks/fractures of the tooth or restoration, inadequate restorations resulting in loss of coronal seal, inadequate aseptic technique, and apical or lateral root canals which have been exposed to microorganisms as a result of deep periodontal pockets or acute dental trauma (such as avulsion) may also contribute to the intraradicular microbial burden resulting in PTED [8,16] (Table 1). ...
... Outline of the factors that may lead to the possible introduction or persistence of microorganisms within the root canal system leading to intraradicular infection[8,11,15,16]. ...
Post‐treatment endodontic disease (PTED) may be defined by the presence of a periapical radiolucency in a previously root‐filled tooth when the lesion can no longer be assumed to be healing. When a diagnosis of PTED is made, theoretically only three management options remain: no treatment (review and reassess), endodontic retreatment (nonsurgical or surgical), or extraction (including root resection). The purpose of this paper is to provide clinicians with a current and clinically relevant summary of the management options for PTED, with an emphasis on aetiology, case selection, and related outcomes to help clinicians filter and provide management options to the patient.
... Effective root canal sealing, including mechanical cleaning, antibacterial irrigants, and antimicrobial dressings, plays a key role in treatment success. [2] Root canal sealers, which should be bacteriostatic, tissue-compatible, and capable of providing an airtight seal, are often incorporated with antimicrobial agents to prevent residual infection. [3] Sealers are classified based on their chemical composition, including zinc oxide-eugenol-based, calcium hydroxide-containing, glass ionomer-based, epoxy resin-based, and mineral trioxide aggregate-based types. ...
A BSTRACT
Objective
The objective of this in vitro study is to evaluate and compare the antibacterial effectiveness of different root canal sealers against Enterococcus faecalis .
Materials and Methods
The antibacterial efficacy of four root canal sealers—three bioceramic materials (TotalFill Bioceramic Sealer, BioRoot Root Canal Sealer, and MTA Fillapex) and one epoxy resin-based sealer (AH Plus)—against E. faecalis (ATCC 29212) was assessed using a modified direct contact test. Every sealer was made under the manufacturer’s instructions, and its antibacterial activity was evaluated against newly mixed and set sealers (1 and 3 days) at various intervals (2, 5, 20, and 60 min). Mitis salivarius agar was used to plate the bacterial suspension, and one-way ANOVA was used for statistical analysis.
Results
TotalFill Bioceramic Sealer showed the highest antibacterial efficacy, followed by BioRoot Root Canal Sealer, MTA Fillapex, and AH Plus.
Conclusion
Bioceramic root canal sealers, particularly TotalFill, demonstrate superior antibacterial efficacy against E. faecalis compared to epoxy resin-based sealers such as AH Plus.
... 4,5 The role of bacteria in the development of pulpal and periapical diseases has been proven in many studies. 6,7 The presence of bacteria leads to pulpal or periapical inflammatory reaction. 8 The severity of the inflammatory response of pulpal and periapical tissue is related to the presence, number and contact time of microorganisms. ...
The aim of this study is the comparison of antibacterial effects of calcium hydroxide medicament and chlorhexidine gluconate gel on Enterococcus faecalis. The study is composed of three experimental groups. Antibacterial effects of group 1, calcium hydroxide medicament (Calcicure); group 2, %1 chlorexidine gluconate gel (Corsodyl) and group 3, combination of calcium hydroxide medicament plus chlorexidine gluconate gel equal ratio were examined with agar diffusion method on the 1st, 2nd and 7th days. Inventions are evaluationed as statistical with ANOVA and multiple comparisons tests. In the end of our study for the three time period the antibacterial effect of chlorexidine gluconate gel was more than calcium hydroxide medicament and the combination of calcium hydroxide medicament plus chlorexidine gluconate gel equal ratio (P0,05), however on the 7th day it is found an important statistical difference (P
... Reinfection of the root canal system causes root canal treatment to fail, and Enterococcus faecalis (E. Faecalis) is a facultative anaerobic Gram-positive bacteria that is frequently associated with recurrent root canal infections [3]. It has shown resistance to calcium hydroxide [4] and the ability to colonize 800-1000 µm into dentinal tubules, while sodium hypochlorite with the conventional method has been shown to only be effective by penetrating up to 300 µm [5]. ...
The purpose of this study was to evaluate the bactericidal effect of 270 nm UV-C light-emitting diode (LED) light delivered through a newly designed prototype device with thin optical fiber against Enterococcus faecalis (E. faecalis). The prototype device, developed to integrate UV-C light into a thin optic fiber (diameter 124 µm) connected to a UV-C LED (Luminous Device; Sunnyvale, CA, USA) via a specialized double-lens system that focuses divergent light to achieve a 65 mm working distance and a numerical aperture of 0.22. E. faecalis, was cultured at 37 °C under aerobic conditions for 24 h. The UV-C LED optical fiber was positioned 10 mm above the bacterial culture prepared in the wells of a 96-well plate. The E. faecalis cells were exposed to UV-C irradiation for 0, 10, 30, 60, 90, 120 and 180 s. Following irradiation, the OD600 values were measured after incubation at 37 °C for an additional 24 h. The data were statistically analyzed using one-way ANOVA, followed by Tukey’s honestly significant difference (HSD) test at a significance level of 0.05. UV irradiation at 270 nm significantly reduced E. faecalis growth in a time-dependent manner (p < 0.05). No significant changes were observed at 0 and 10 s, while peak reductions occurred at 120 and 180 s, with effects beginning at 30 s and increasing over time. The 270 nm UV-C wavelength was highly effective in bactericidal action against E. faecalis. The custom-designed UV-C delivery system effectively integrated the light source into a thin optical fiber, allowing for efficient UV-C light transmission and demonstrating its potential for application in narrow spaces such as root canals.
... The goal of retreatment (Retx) in endodontics is to remove microorganisms, relieve symptoms, and preserve the natural tooth by addressing issues that may have caused the failure of the primary root canal treatment. Key objectives include removing sources of persistent infection such as residual bacteria, tissue, and debris [1]. Retreatment requires the removal of the previous root canal filling material and instrumenting the canal to regain access to the apical foramen [2]. ...
Recently, the single-cone hydraulic canal filling technique using bioceramic sealers was found to hinder retreatment due to the mechanical properties of the bioceramic sealers. This study assessed the effectiveness of four nickel–titanium rotary files in removing gutta-percha and bioceramic sealer from molar root canals in vitro. Eighty-eight root canals from extracted molars were instrumented with Vortex Blue rotary files and filled with gutta-percha and bioceramic sealer using a single-cone technique. After 30 days, the filled canals were randomly divided into four groups according to the file used for re-instrumentation: ProTaper Gold (PTG), Endo ReStart (ERS), XP-3D Shaper (XPD), and HyFlex Remover (HFR). This study assessed whether root canal filling material removal and patency were achieved within a 10-min time frame, recording the time required in seconds. The rate of regaining patency and the time required to achieve patency were compared among groups using a generalized linear model. Scanning electron microscopy was used to evaluate the mechanical changes to the files after use. The patency rate of XPD and HFR was significantly higher than PTG. ERS and XPD demonstrated shorter patency times than HFR and significantly shorter patency times than PTG. SEM images revealed a varied range of reverse windings across file groups. PTG and ERS exhibited microcracks and fractured tips, while XPD and HFR did not display these mechanical alterations. The four file systems in this study displayed varying levels of effectiveness in the retreatment of root canals filled with bioceramic sealers.
Background
Root canal treatment (RCT) failure occurs due to persistent infections, missed canals, or anatomical complexities, with Enterococcus faecalis being the predominant microorganism associated with treatment failure. This study aimed to determine the prevalence of E. faecalis in failed root canal cases and its correlation with clinical parameters.
Materials and Methods
A cross-sectional study was conducted on 50 patients aged 18–50 years requiring nonsurgical endodontic retreatment. Samples were collected using sterile paper points, gutta-percha, and oral swabs. Clinical data such as age, gender, tooth location, and radiographic findings were documented.
Results
All samples exhibited polymicrobial infections. E. faecalis was the most prevalent species predominantly isolated using paper points. Other organisms included Streptococcus spp., Candida spp., and Escherichia coli . Oral swabs showed lower detection rates for E. faecalis as compared to other samples for microbial isolation, Gram-positive bacteria (86%) dominated, followed by Gram-negative bacteria (8.3%) and yeast (5%). The findings confirm E. faecalis as the most prevalent microorganism in failed RCT cases. Its resilience, ability to form biofilms, and resistance to conventional treatment contribute to persistent infections. No significant correlation was observed between bacterial prevalence and demographic factors or tooth position. Differences in microbial detection rates among sampling methods emphasize the importance of multiple sampling approaches for accurate microbial recovery.
Conclusion
E. faecalis is highly prevalent in refractory endodontic infections, underscoring its role in treatment failure. The use of sterile paper points and gutta-percha samples effectively detects intracanal microbes. Advanced molecular techniques may further improve the understanding of endodontic microbiota and help reduce failure rates.
This chapter reports on the possible complications that can be related to the procedures for filling the root canal system. It begins with a brief introduction and a description of the most common filling materials used in Endodontics, their characteristics and their history. The different obturation techniques used to fill the root canals in three dimensions will be also described to better understand possible complications due to technical problems. Difficulties arising while using the various obturation techniques will be extensively described, including the descriptions of the complications due to the obturation procedures, their prevention and their management. The possible consequences of the extrusion of filling materials over the apex will be described, giving particular attention to the description of the anatomical areas that may be possibly involved. Complications due to the chemical effect, the heat, and the mechanical damage will also be described and discussed.
The microbial aetiology of endodontic disease has been long established. The endodontic niche represents a very specific environment for the development of resilient bacterial community in the form of biofilms. The clinician should gather all the clinical evidence to achieve a thorough diagnosis of the type and level of infection present. In particular, those clinical signs that are associated with refractory endodontic infection should be detected. The systematic condition of the patient may lead to relapse of the endodontic pathology. However, local factors and signs are more preponderant indicating the presence of a refractory endodontic infection. The presence of long-standing fistulae, with associated development of extra-radicular biofilm or complex tooth anatomy will limit the possibility to fully disinfect the root canal system. The restorability and the coronal seal play an important role in preventing the risk of reinfection following root canal treatment. Also, several operative approaches are described to limit the chance of iatrogenic contamination of the root canal system. Particular emphasis is given to the more efficient shaping approaches. The irrigation still plays an ultimate role in the eradication of the endodontic biofilms. The correct irrigation regimen should be adopted to maximise its efficiency. Modern adjunct disinfection techniques are nowadays available: sonic and ultrasonic activation and photodynamic therapy are advanced tool to reach otherwise inaccessible areas. In the future, together with the aforementioned strategies, the detection in real time of the residual bacterial contamination post-treatment will help the clinicians to maximise the endodontic outcome.
Background
The goal of the present study was to assess the effectiveness of natural irrigants on the push-out bond strength (PBS) of AH plus and gutta-percha (GP).
Aim
The aim is to evaluate the effect of chitosan and a combination of Citrus aurantifolia (CA) and Sapindus mukorossi (SM) on the PBS of AH Plus and GP.
Methodology
Thirty mandibular premolars were selected. Using a 15-k file canal patency was confirmed and samples were decoronated to a 15 mm standard length. Three groups have been established based on the irrigating procedures used with the samples. Group 1 ( n = 10): 3 mL 5.25% sodium hypochlorite (NaOCl) for 1 min and 17% ethylene diamine tetraacetic acid (EDTA) for 1 min; Group 2 ( n = 10): 3 mL of a 2:1 ratio of CA and SM solution; and Group 3 ( n = 10): 3 mL of 0.2% chitosan. Samples were finally rinsed with 5 mL of distilled water. After being dried, samples were obturated using the corresponding GP and AH plus. At the coronal level, 2 mm of horizontal sections were made, and the PBS was tested. ANOVA and post hoc Tukey’s tests were employed to statistically assess the results, using a significance level of P < 0.05.
Results
The highest PBS was observed in Group 1 (2.22 MPa), and Group 2 (1.3 MPa) showed the lowest PBS values.
Conclusion
Irrigation with NaOCl/EDTA and chitosan showed better results compared to the CA and SM combination regarding the PBS of AH plus and GP.
The effect of endodontic irrigants and dressings was tested on bacteria in bovine dentin specimens experimentally infected with Enterococcus faecalis, Streptococcus sanguis, Escherichia coli, or Pseudomonas aeruginosa. Standardized, cylindrical dentin test pieces were prepared and cleaned by ultrasonic treatment with EDTA and sodium hypochlorite. The specimens were infected with the test organism for periods up to 14 days, and the degree of infection into the tubules was monitored using Brown & Brenn stain, scanning electron microscopy, and culturing of dentin dust from sequential bur samples starting from the pulpal side. E. faecalis rapidly infected the whole length of the tubules; S. sanguis required up to 2 weeks for complete infection; E. coli only penetrated to some 600 microns, even after prolonged incubation periods. P. aeruginosa infected dentin quickly, but apparently in very low numbers. E. faecalis persisted for at least 10 d after withdrawal of nutrient support, whereas the other 3 organisms died within 4 to 48 h. Endodontic medicaments were applied to infected specimen for comparison of antibacterial potency. Camphorated p-monochlorophenol was generally more efficient than Calasept, and of the irrigants tested, iodine potassium iodide appeared more potent than sodium hypochlorite or chlorhexidine. The presence of a smear layer delayed, but did not eliminate, the effect of the medicaments.