Endodontic Pathogens Research Articles

In vitro Comparative Evaluation of the Antibacterial and Antifungal Activities of Different Root Canal Sealers against Endodontic Pathogens

In vitro Comparative Evaluation of the Antibacterial and Antifungal Activities of Different Root Canal Sealers against Endodontic Pathogens

Antibiotic susceptibility of endodontic pathogens: A systematic review

Antibiotic susceptibility of endodontic pathogens: A systematic review

Efficacy of Endodontic Treatment on the Persistence of Selected Endodontic Pathogens and on Radiographical Periapical Healing

The objective of this clinical study was to evaluate by polymerase chain reaction (PCR) the antimicrobial efficacy and the outcome of an endodontic protocol treatment (EPT) performed by under-graduated dental students on infected root canals associated with periapical lesions. Fifty-six patients attending for treatment of pulp necrosis and apical periodontitis were included. A specific EPT approach was performed and DNA extracts were taken at the baseline (S1), after a disinfection-neutralization procedure (S2), post-chemomechanical preparation (S3) and after Intracanal medication (S4) for the presence of specific bacteria. The outcome of the EPT was assessed radiographically using the Periapical Index-system (PAI) after 18-month follow-up. An intergroup evaluation shows that when comparing S1 to S3, S1 to S4, S2 to S3, and S2 to S4, the presence of bacteria were significantly reduced (P < 0.05). Finally, S4 was not significantly reduced when compared with S3 (P > 0.05). The most prevalent species in their respect order were Actinomyces Israelii > Enterococcus Faecalis > Fusobacterium Nucleatum/Prevotella Nigrescens > Phorphyromonas Endodontalis. After the 18-month follow-up, the overall success rate of root canal – treated teeth was of 88% (PAI 1 or 2). This In Vivo study demonstrated that EPT significantly reduced the number of cases with positive results for the studied bacteria, showing a profound positive impact in the outcome of endodontic treatment of teeth diagnosed with Pulp Necrosis and Apical Periodontitis.

Transcription factor Rex in regulation of pathophysiology in oral pathogens.

The NAD(+) and NADH-sensing transcriptional regulator Rex is widely conserved across gram-positive bacteria. Rex monitors cellular redox poise and controls the expression of genes/operons involved in diverse pathways including alternative fermentation, oxidative stress responses, and biofilm formation. The oral cavity undergoes frequent and drastic fluctuations in nutrient availability, pH, temperature, oxygen tension, saliva, and shear forces. The oral streptococci are major colonizers of oral mucosa and tooth surfaces and include commensals as well as opportunistic pathogens, including the primary etiological agent of dental caries, Streptococcus mutans. Current understanding of the Rex regulon in oral bacteria is mostly based on studies in S.mutans and endodontic pathogen Enterococcus faecalis. Indeed, other oral bacteria encode homologs of the Rex protein and much is to be gleaned from more in-depth studies. Our current understanding has Rex positioned at the interface of oxygen and energy metabolism. In biofilms, heterogeneous oxygen tension influences the ratio of intracellular NADH and NAD(+) , which is finely tuned through glycolysis and fermentation. In S.mutans, Rex regulates the expression of glycolytic enzyme NAD(+) -dependent glyceraldehyde 3-phosphate dehydrogenase, and NADH-dependent fermentation enzymes/complexes lactate dehydrogenase, pyruvate dehydrogenase, alcohol-acetaldehyde dehydrogenase, and fumarate reductase. In addition, Rex controls the expression of NADH oxidase, a major enzyme used to eliminate oxidative stress and regenerate NAD(+) . Here, we summarize recent studies carried out on the Rex regulators in S.mutans and E.faecalis. This research has important implications for understanding how Rex monitors redox balance and optimizes fermentation pathways for survival and subsequent pathogenicity.

Combined effects of photodynamic therapy and irrigants in disinfection of root canals.

In this study, the combined effects of photodynamic therapy and irrigants in eradicating common endodontic pathogens are evaluated. Roots of 80 extracted single rooted teeth are divided into 2 groups (1) mechanical flushing; (2) antibacterial irrigation. After cleaning and shaping, they are inoculated with either (A) Streptococcus mutans or (B) Enterococcus faecalis and incubated. They are again subdivided and either only irrigated or irrigated and lased. Dentin shavings are taken from root canal walls and cultured. Statistical analysis using One-Way ANOVA and Post-hoc tests are done. The combination eradicated both bacteria. Antibacterial irrigants controlled S. mutans better than PDT (p=0.041). The combination of PDT and antibacterial irrigation proposed in this study can be used in all primary cases for thorough and reliable disinfection of root canals but may be highly effective in resistant cases like endodontic failures, as E.faecalis is prevalent in such cases.

Early Cytokine Response to Infection with Pathogenic vs Non-Pathogenic Organisms in a Mouse Model of Endodontic Infection.

Using the subcutaneous chamber model of infection, we showed previously that a mixture of four endodontic pathogens (EP: P. intermedia, F. nucleatum, S. intermedius and P. micra) are able to persist without clearance for up to seven days, while a non-pathogenic oral species, S. mitis, was substantially cleared in this time. Here we have compared the cytokine response inside the chambers against these microorganisms. A majority of cytokines tested (17/24) showed different patterns of expression. Several cytokines had a peak of expression at 2 h after infection in response to the EP, while none showed this pattern in S. mitis infections. Chemokines were uniformly present at similar or higher levels in response to S. mitis, with redundant expression of CXCR2 ligands, while several growth/survival factors were present at higher levels in EP infections. Protease activity expressed by EP may be responsible for the lower levels of some chemokines. T-cell associated cytokines were in general expressed at extremely low levels, and did not differ between the two infections. The inflammatory markers IL-6, IL-1α and IL1-β were expressed at similar levels in both infections at early times, while TNFα was preferentially present in S. mitis infections. In EP infected chambers, reciprocal changes in levels of IL-6 and IL-1α were observed at later times suggesting a switch in the inflammatory response. Analysis of the cytokine response to infection with the individual species from the EP mix suggests that P. intermedia drives this inflammatory switch. Together these results show a surprising level of divergence of the host response to pathogenic and non-pathogenic organisms associated with oral infections, and supports a dominant effect of P. intermedia in polymicrobial endodontic infections.

Microbiological Analysis of Teeth with Chronic Apical Periodontitis and the Outcome of Treatment by Gutta Percha Points Impregnated with Either Calcium Hydroxide or Chlorhexidine as Intra Canal Medicament

Microbiological analysis of teeth with chronic apical periodontitis and the outcome of treatment by gutta percha points impregnated with either calcium hydroxide or chlorhexidine as intra canal medicament Bacteria have a major role in the success of an endodontic treatment. Mechanical preparation alone cannot effectively eliminate bacteria from dentinal tubules and other irregularities in the root canal. Few remnant microorganisms can multiply between appointments often reaching the same level as at the start of the previous session. These observations call for an effective intracanal medication that will help to disinfect the root canal system. Calcium hydroxide has an antibacterial effect on most of the endodontic pathogens. This is due to its high alkalinity. It damages the bacterial cytoplasmic membrane. Chlorhexidine has been found to have a broad-spectrum antimicrobial action and relative absence of toxicity. Calcium hydroxide points as well as chlorhexidine gutta percha points are ready to be used in a flexible way and easily to be introduced into the canal. Three bacterial cultures - before, after instrumentation and after medication by either one of the experimental materials - were taken from forty healthy patients having non-vital single rooted teeth with chronic apical periodontitis. Twelve types of bacteria were commonly isolated with different frequencies. Anaerobes represented about 56.1 % and aerobes represented about 43.9 % of the total bacteria. Streptococcus mitis (15.2 %) was the most frequent isolated bacteria (aerobes and anaerobes) from all the cases in the 1st culture. Then it was followed by Prevotella intermedia (14.7 %), Peptostreptococcus spp. (10.5%), Eubacterium lentum (9.4 %), Lactobacillus spp. (8.9 %), Staphylococcus aureus (8.4 %), Veillonella parvula (7.9 %), Enterococcus faecalis (7.3 %), Escherichia coli (E-coli) (6.8 %), Neisseria catarrhalis (5.2 %), Proionibacterium spp. (4.7 %), Staphylococcus epidermis (1 %). The results demonstrated a highly significant reduction in the bacterial growth in the experimental groups before and after instrumentation and medication of the root canal when compared to the control. Chlorhexidine gutta percha points proved to have a significant better antibacterial effect than calcium hydroxide gutta percha points.

Total and Specific Bacterial Levels in the Apical Root Canal System of Teeth with Post-treatment Apical Periodontitis

IntroductionMost studies of the microbiota in root canal–treated teeth focused only on the main canal, not distinguishing regions nor incorporating the intricate anatomy in the analysis. Moreover, most of them provided only prevalence data. This study was designed to evaluate the total bacterial counts and the presence, levels, and relative abundance of candidate endodontic pathogens exclusively in the apical root canal system associated with post-treatment apical periodontitis. MethodsApical root specimens obtained during periradicular surgery of 27 adequately treated teeth with persistent apical periodontitis were cryogenically ground. DNA was extracted from the powder, and real-time polymerase chain reaction was used to quantify the total bacteria and 7 bacterial taxa. ResultsSamples from 21 teeth were positive for bacteria. Streptococcus species were the most prevalent (76%) followed by members of the Actinobacteria phylum (52%) and Pseudoramibacter alactolyticus (19%). The mean total bacterial load in the apical root segments was 5.7 × 104 cell equivalents per root apex (or 2.1 × 104/100 mg root powder). Streptococci comprised from 0.02%–99.9% of the total bacterial counts, Actinobacteria from 0.02%–84.7%, and P. alactolyticus from 67.9%–99%. Although Enterococcus faecalis was found in only 3 (14%) cases, it was dominant in 2. ConclusionsStreptococcus species, members of the Actinobacteria phylum, and P. alactolyticus were the most prevalent taxa in the apical canal system and dominated the bacterial populations in many cases of post-treatment apical periodontitis.

A Comparative Analysis of Antimicrobial Property of Wine and Ozone with Calcium Hydroxide and Chlorhexidine.

The antibacterial properties of wine and ozone have been established but their antibacterial efficacies against endodontic pathogens are yet to be ascertained. The purpose of this study is to comparatively evaluate the antibacterial property of ozonated water, white wine (14%) and de-alcoholised white wine. S.mutans and E.faecalis were subcultured and inoculated in a nutrient broth for 24 hours. The following groups were formulated: Group 1A:2% Chlorhexidine (Control group); Group 1B:White wine; Group 1C:Dealcoholised white wine; Group 1D:Ozonated water; Group 2A: Ca(OH)2 + Chlorhexidine (Control group); Group 2B: White wine + Ca(OH)2; Group 2C:De-alcoholised White wine + Ca(OH)2 + chlorhexidine; Group 2D:White wine + Ca(OH)2 + chlorhexidine and group 2E: Dealcoholised white wine + Ca(OH)2 + chlorhexidine. The samples were allowed to diffuse into the culture medium for two hours, later the S. mutans were streaked on to the blood agar medium and the E. faecalis were streaked on to the Muller Hilton agar medium and incubated for 48 hours at 370C the zone of inhibition was measured after 48 hours. There was no growth of microorganisms seen with ozonated water. Chlorhexidine showed large zone of inhibition compared to the other groups. White wine has better antimicrobial property than de-alcoholised white wine, but when mixed with calcium hydroxide the dealcoholised white wine has better action against the microorganisms. Ozonated water has the best antibacterial property and the antibacterial action of Calcium hydroxide is enhanced when it is mixed with de-alcoholised white wine.

Antimicrobial activity of herbal extracts against recalcitrant endodontic pathogens: An original in vitro study

Introduction: Plants have been used for health disorders and to prevent diseases including epidemics since times immemorial. The knowledge of their healing properties has been transmitted over the centuries within and among human communities. Aims and Objectives: To evaluate and compare the antimicrobial potential of herbal extracts, namely neem (Azadirachta indica), tulsi (Ocimum sanctum), bitter gourd (Momordia charantia), and arka (Calotropis procera) as endodontic irrigants against Enterococcus faecalis and Candida albicans in vitro. Materials and Methods: Agar well diffusion test was performed. The inoculums of E. faecalis and C. albicans were streaked on the blood agar plate, and wells were made using cork borers. The prepared herbal extracts of the test samples were loaded onto agar plate. The plates were incubated at 37°C for 24 h. The inhibition zones indicating the antimicrobial potential were measured using a millimeter scale and results were analyzed statistically. Results: Bitter gourd showed the maximum zones of inhibition followed by neem, tulsi, and calotropis for both E. faecalis and C. albicans. Conclusion: The tested irrigants showed significant antimicrobial efficacy against E. faecalis and C. albicans. Thus, the use of herbal alternatives as root canal irrigants might prove advantageous considering the undesirable characteristics of presently used irrigants.

Antibacterial efficacy of Azadirachta indica, Mimusops elengi and 2% CHX on multispecies dentinal biofilm.

Aims:To check the antimicrobial activity of Azadirachta indica (Neem), Mimusops elengi (Bakul), and Chlorhexidine gluconate (CHX) on multispecies biofilm of common endodontic pathogens such as Streptococcus mutans, Enterococcus faecalis, Staphylococcus aureus and Candida albicans.Settings and Design:In vitro dentin disinfection model used to check the antimicrobial efficacy of herbal extracts.Materials and Methods:The in vitro dentin disinfection model was used to check the antimicrobial activity of the methanolic extracts of the medicinal plants along with Chlorhexidine gluconate. The polymicrobial biofilm was allowed to grow on extracted teeth sections for a period of 21 days. Remaining microbial load in the form of CFU/ml after the antimicrobial treatment was tabulated, and data were statistically analyzed using ANOVA and Bonferroni post-hoc tests.Statistical Analysis Used:SPSS version 17, one-way ANOVA, Bonferroni post-hoc test.Results:Both the plant extracts showed considerable antimicrobial efficacy as compared to negative control. 2% CHX was the most effective antimicrobial agent having statistically significant difference against plant extracts and negative control (saline).Conclusion:The methanolic extract of A. Indica, M. elengi, and Chlorhexidine Gluconate has considerable antimicrobial activity against polymicrobial dentinal biofilm of S. mutans, E. faecalis, S. aureus and C. albicans.

Identification of Enterococcus faecalis antigens specifically expressed in vivo.

ObjectivesMolecular mechanism of the pathogenicity of Enterococcus faecalis (E. faecalis), a suspected endodontic pathogen, has not yet been adequately elucidated due to limited information on its virulence factors. Here we report the identification of in vivo expressed antigens of E. faecalis by using a novel immunoscreening technique called change-mediated antigen technology (CMAT) and an experimental animal model of endodontic infection.Materials and MethodsAmong 4,500 E. coli recombinant clones screened, 19 positive clones reacted reproducibly with hyperimmune sera obtained from rabbits immunized with E. faecalis cells isolated from an experimental endodontic infection. DNA sequences from 16 of these in vivo-induced (IVI) genes were determined.ResultsIdentified protein antigens of E. faecalis included enzymes involved in housekeeping functions, copper resistance protein, putative outer membrane proteins, and proteins of unknown function.ConclusionsIn vivo expressed antigens of E. faecalis could be identified by using a novel immune-screening technique CMAT and an experimental animal model of endodontic infection. Detailed analysis of these IVI genes will lead to a better understanding of the molecular mechanisms involved in the endodontic infection of E. faecalis.

PCR identification of endodontic pathogens and DNA quantification in samples from teeth with posttreatment apical periodontitis

Aim: The aim of this clinical study was to quantify the concentration of DNA and to detect selected bacterial species from samples of infected root-fi lled teeth with post-treatment apical periodontitis after removal of gutta-percha (S1), after chemo-mechanical preparation at the fi rst appointment (S2), 5 days after the canal was fi lled with sterile physiological solution (S3), after reinstrumentation at the second appointment (S4), and 14 days after an intracanal dressing was placed at the third appointment (S5). Methods: Fifteen root-fi lled teeth were selected. Removal of gutta-percha was performed using the crown-down technique. Chemo-mechanical preparation was performed with hand fi les associated with 2% chlorhexidine gel. An intracanal dressing based on Ca(OH)2 was used. DNA was extracted from the samples and 14 endodontic 16S rDNA species-specifi c primers were tested. The concentration of DNA was quantifi ed using a NanoDropTM 2000 spectrophotometer. Results: Bacteria were present in all cases at all sampling times, as revealed by a universal primer. DNA was isolated from all samples, with an average concentration of 4.24 ± 2.9 ng/µL (S1), 3.39 ± 1.54 ng/µL (S2), 4.0 ± 1.94 ng/µL (S3), 2.66 ± 0.98 ng/µL (S4) and 3.97 ± 2.32 ng/µL (S5). Parvimonas micra and Enterococcus faecalis (S1), P. micra (S2), Porphyromonas endodontalis and E. faecalis (S3), E. faecalis and Prevotella nigrescens (S4/S5) were the species most frequently deteced. DNA concentration reductions were detected between S3 and S4 (p = 0.0256), whereas an increase was found between S4 and S5. Conclusion: A wide variety of bacterial species was detected in root-fi lled teeth with post-treatment apical periodontitis. Moreover, the use of an intracanal dressing was unable to further reduce the concentration of bacterial DNA.

Analysis of antimicrobial activity of root canal sealers against endodontic pathogens using agar diffusion test (In vitro study)

Antibacterial action of root canal filling is an important factor for successful root canal treatment, so the aim of the study was to identify and to compare the antimicrobial effect of new sealer (GuttaFlow) to commonly used endodontic sealers (AH Plus, Apexit and EndoFill) against four endodontic microbes. Materials and methods: Twenty patients aged (30-40) years with infected root canals were selected. Four types of microorganisms were isolated from root canals (E faecalis, Staphylococcus aureus, E coli and Candida albicans) and cultured on Mueller Hinton agar Petri-dishes. After identification and isolation of bacterial species, agar diffusion method was used to assess the antibacterial action of four contemporary endodontic sealers used in root canal obturation (AH Plus, Apexit, EndoFill and GuttafFlow). Four wells measuring (5mm depth and 4mm diameter) were created in each Petri dish and sealer was applied into them incubated overnight at 37 C° for bacterial species and 48 hr. at 37 C° for Candida albicans prior to determination of results. Zones of inhibition (no growth of bacteria) were examined around the wells containing sealer & diameters of the zones were measured in mm. The mean of inhibition zones for each group was measured and statistically analyzed among groups using ANOVA and between groups using LSD tests. Results: There was a highly significant difference (P<0.001) among all the tested groups. EndoFill showed the maximum antibacterial action against tested microorganisms. GuttaFlow showed moderate to weak antimicrobial effect, Apexit had weak effect, while AH Plus had no antibacterial action. Conclusion: All the tested materials except AH Plus had antibacterial efficacy against E faecalis, Staphylococcus aureus, E coli and Candida albicans. EndoFill had favorable results among tested sealers and E faecalis was the most resistant bacteria, but none of the materials totally inhibited microbial growth. Thus, endodontic treatment must be

Pathogenic bacterial species associated with endodontic infection evade innate immune control by disabling neutrophils.

Endodontic infections, in which oral bacteria access the tooth pulp chamber, are common and do not resolve once established. To investigate the effects of these infections on the innate immune response, we established a mouse subcutaneous chamber model, where a mixture of four oral pathogens commonly associated with these infections (endodontic pathogens [EP]), i.e., Fusobacterium nucleatum, Streptococcus intermedius, Parvimonas micra, and Prevotella intermedia, was inoculated into subcutaneously implanted titanium chambers. Cells that infiltrated the chamber after these infections were primarily neutrophils; however, these neutrophils were unable to control the infection. Infection with a nonpathogenic oral bacterial species, Streptococcus mitis, resulted in well-controlled infection, with bacterial numbers reduced by 4 to 5 log units after 7 days. Propidium iodide (PI) staining of the chamber neutrophils identified three distinct populations: neutrophils from EP-infected chambers were intermediate in PI staining, while cells in chambers from mice infected with S. mitis were PI positive (apoptotic) or negative (live). Strikingly, neutrophils from EP-infected chambers were severely impaired in their ability to phagocytose and to generate reactive oxygen species in vitro after removal from the chamber compared to cells from S. mitis-infected chambers. The mechanism of neutrophil impairment was necrotic cell death as determined by morphological analyses. P. intermedia alone could induce a similar neutrophil phenotype. We conclude that the endodontic pathogens, particularly P. intermedia, can efficiently disable and kill infiltrating neutrophils, allowing these infections to become established. These results can help explain the persistence of endodontic infections and demonstrate a new virulence mechanism associated with P. intermedia.

In vitro and ex vivo antimicrobial efficacy of nano-MgO in the elimination of endodontic pathogens.

The use of metal oxide nanoparticles has attracted lots of attention, mostly because of their promising antimicrobial activity along with their biocompatibility with mammalian cells. This study aims to investigate the in vitro and ex vivo antimicrobial efficiency of nano-magnesium oxide (MgO) aqueous solution against endodontic pathogens. The cytotoxicity of different concentrations of nano-MgO was assessed using lactate dehydrogenase cytotoxicity assay (LDH assay). A comparison of the antimicrobial efficiency of several concentrations of nano-MgO solution, sodium hypochlorite (NaOCl), and chlorhexidine (CHX) gluconate against Staphylococcus aureus, Enterococcus faecalis, and Candida albicans was made using the direct contact method. An ex vivo model of decoronated and experimentally infected human teeth was employed to compare the efficiency of nano-MgO (5 mg/L) solution with NaOCl (5.25 %) in the elimination of E. faecalis. There was no statistically significant difference between nano-MgO solutions (10 and 5 mg/L), 5.25 % NaOCl, and 2 % CHX gluconate in terms of the required time to inhibit the growth of the tested pathogens (p > 0.05). The LDH assay showed no cytotoxicity of different concentrations of nano-MgO used in this study (p < 0.001). In the ex vivo model of infected human teeth, 6 h post-irrigation, there was no statistically significant difference between colony-forming units (CFU) per milliliter of nano-MgO (5 mg/L) and NaOCl (5.25 %)-treated teeth (5-6 log scale reduction). However, the nano-MgO group showed a significant decrease in colony-forming units per milliliter (7 log scale), 24 h post-irrigation (p < 0.05). At other tested time points-24, 48, 72, and 168 h-the levels of CFU per milliliter were significantly less in the nano-MgO group (2-3 log scale difference) compared to the NaOCl group, indicating long-term antibacterial activity of nano-MgO (p < 0.05). At 72 and 168 h post-irrigation, no detectable bacterial growth was observed in the nano-MgO group. The detection limit was 10 CFU/mL. Nano-MgO aqueous solutions represent promising antimicrobial activities, both in vitro and ex vivo with minimal toxicity. Compared to NaOCl (5.25 %), nano-MgO (5 mg/L) exhibits statistically significant long-term efficiency in the elimination of E. faecalis in the root canal system. After further investigations, nano-MgO could be considered as a new root canal irrigant.

Evaluation of the Antibacterial Effect of MTAD and Sodium Hypochlorite against Endodontic Pathogens

The purpose of this investigation was to compare the efficacy of Biopure MTAD versus 5.25% NaOCl as irrigant solutions for root canals infected with E. faecalis and Strept. Mutans. <b>Materials and Methods:</b> Forty extracted human single-rooted lower premolar teeth are decoronated at the cemento-enamel junction (CEJ). The roots will instrumented by k-file till size 40 then these teeth will contaminated by bacteria in brain heart infusion for 48 hrs. The samples will divide into 3 groups (MTAD, NaOCl and normal saline). Dentin chips will removed from the canal with sterile low speed hand piece round bur the collected dentin chips will transfer by BHI and culture on the media and the growing colonies will count and record as colonies forming unit (CFU). <b>Results:</b> The antibacterial activity of Biopure MTAD was significantly differ from that of 5.25% NaOCl and distilled water.Conclusion: Biopure MTAD has the strongest antibacterial effect against E.faecalis and Strept. mutans than 5.25% NaOCl and distilled water.

The antimicrobial activity of Azadirachta indica, Mimusops elengi, Tinospora cardifolia, Ocimum sanctum and 2% chlorhexidine gluconate on common endodontic pathogens: An in vitro study.

Objective:To check the antimicrobial activity of Azadirachta indica (Neem), Ocimum sanctum (Tulsi), Mimusops elelngi (Bakul), Tinospora cardifolia (Giloy) and Chlorhexidine Gluconate (CHX) on common endodontic pathogens like Streptococcus mutans, Enterococcus faecalis and staphylococcus aureus.Materials and Methods:The agar diffusion test was used to check the antimicrobial activity of the Methanolic extracts of the medicinal plants along with CHX. Six different concentrations of the tested agents were used for the study. The values of Zone of Inhibition were tabulated according to the concentration of the tested agent and data was statistically analyzed using ANOVA and Bonferroni post- hoc tests. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentrations (MBC) values were also recorded.Results:All the plants extracts showed considerable antimicrobial activity against selected endodontic pathogens. At 3mg. concentration, O.sanctum was the most effective against S. mutans, M. elengi showed highest zone of inhibition against E.faecalis, whereas CHX was the most effective agent against S.aureus. CHX was also the most consistent of all the medicaments testes, showing inhibitory effect against all the tree pathogens at all the selected concentrations.Conclusions:The Methanolic extract of A.Indica, O.sanctum, M. Elengi, T.cardifolia and Chlorhexidine Gluconate has considerable antimicrobial activity against S. mutans, E. faecalis and S. aureus.

Investigate the correlation between clinical sign and symptoms and the presence of P. gingivalis, T. denticola, and T. forsythia individually or as a "Red complex" by a multiplex PCR method.

Aim:The aim of this study was to investigate the correlation between endodontic clinical signs and symptoms and the presence of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia or their association by Multiplex polymerase chain reaction assay.Materials and Methods:Microbial samples were taken from 30 cases with necrotic pulp tissues in primary infections. DNA was extracted from the samples, which were analyzed for the presence of three endodontic pathogens by using species-specific primers.Results:P. gingivalis, T. denticola, T. forsythia, and Red Complex were present in 11, 17, 4, and 2 canals, respectively. Clinical and statistically significant relationships were found between T. forsythia and mobility and between T. denticola and swelling. (P < 0.05). Presence of other Red complex bacteria shows clinical association with presence of signs and symptoms but no statistically significant relationship.Conclusion:The high prevalence of P. gingivalis, T. denticola, and T. forsythia in the examined samples suggests that these bacteria are related to the etiology of symptomatic periradicular diseases.

Bacterial Identification in Symptomatic and Asymptomatic Endodontic Infections by Culture Method

The aim of this study was to investigate the microorganisms from of necrotic root canals and to study the associations between symptoms and certain bacterial species, using culture methods. Nineteen symptomatic and twenty-one asymptomatic cases, between 18 to 75 years, having primary endodontic infections, and adhering to the inclusion and exclusion criteria were selected for this study. The targeted microorganisms were Prevotella, Porphyromonas, A.actinimycetmcomitans. E.faecalis.. The organisms that were detected were, Porphyromonas gingivalis, Aggregatibactor actinomycetemcomitans , Prevotella and additional important bacteria like Streptococci, Fusobacterium nucleatum, Klebsiella Capnocytophaga were found by culture analysis, but microorganisms such as and E. faecalis could not be identified. No association was seen between symptoms and bacterial species detected. 1 . The goal of endodontic treatment is the eradication of these microbes. Current treatment protocols like isolation, canal preparation, antibacterial irrigants and intracanal medicaments, are directed towards bacterial elimination. The rationale for the development of treatment protocols are all based on data involving microbiological root canal sampling (MRS) as there is an intimate involvement of bacteria and clinical endodontics. Microbiological root canal sampling is the foundation of clinical endodontics. 2 The finding from microbiologic studies conducted at different parts of the globe reveal that a given species that is very prevalent in root canals of patients from some geographic regions is not necessarily found in similar figures or even detected in samples from other locations. 3 Studies have suggested that genetic and environmental factors can influence the composition of oral microbiota particularly with regard to the periodontal pathogens. 4,5 It is well known that most periodontal pathogens are also endodontic pathogens and as a consequence variations in their prevalence have a potential to exert a significant influence in the composition of the microbiota of infected root canals. Similar variations were seen in microflora of endodontic infections. 6 Endodontic infection can be symptomatic or asymptomatic and the factors responsible for the development of symptoms are not completely understood. Early studies attempted to correlate some bacterial species with symptoms, but it has been demonstrated that the same species can also be found in asymptomatic cases. It seems that the appearance of symptoms might be a result of a complex mechanism, depending on diverse pathogen related and host-related factors. Despite the availability of various molecular methods for the evaluation of microbes, culture analyses are not redundant. The advantage of cultivation approaches are related to their broad-range nature, which makes it possible to identify a great variety of microbial species in a sample, including those that are not being sought after. Cultivation makes it possible to study the physiological properties and pathogenicity of the microbes. There has been a significant focus recently on developing methods for the in-vitro cultivation of those species that were till recently refractory to culture. Use of dilute nutrient media, increasing the incubation time, modification of the culture media with addition of specific substrates, co-cultivation with helper strains, colony hybridization method, used in isolation or in combination have helped in the culturing of hitherto uncultivable microbes. 7 An effort has been made in this study to identify the microbes in symptomatic and asymptomatic primary endodontic infections in patients, by the culture method.