In Vitro Evaluation of a New Combination of Three Antibiotic Paste Against Common Endodontic Pathogens

Herbal extracts have evoked interest owing to the small number of terpenoids and phenolic compounds, which impart antimicrobial, antioxidant, and anti-inflammatory properties. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) of four herbal extracts (lemon grass oil, basil oil, peppermint oil, and Obicure tea extract) against endodontic pathogens along with the MIC: MBC/MFC ratio were evaluated. The antimicrobial activity by detecting the MIC of three essential oils and tea extract was evaluated against eight common endodontic pathogens by the broth dilution method, while MBC was detected by subculturing onto blood agar from the first –three to five tubes from the MIC dilution tubes (showing no turbidity), which were plated on blood agar. All herbal extracts proved to be effective antimicrobials against tested endodontic pathogens. Basil oil had a bacteriostatic effect on all the organisms (P < 0.05). Mint oil showed bacteriostatic activity on Enterococcus (E.) faecalis and Peptostreptococcus (P > 0.05). Tea extract had a bacteriostatic effect (P > 0.05) against all tested microbes except Actinomyces, Lactobacilli, Staphylococcus (S.) aureus, and Fusobacterium (F.) nucleatum. Lemon grass oil had a bactericidal effect against all the organisms and a bacteriostatic effect against Peptostreptococcus (P > 0.05). It can be concluded that basil oil showed a strong bactericidal effect on the test organisms. The MIC for the organisms ranged from 0.2 to 50 μg/ml.

Sir, It is with great interest that we have read the article entitled “Estimation of MBC: MIC Ratio of Herbal Extracts against Common Endodontic Pathogens” published in the Journal of Pharmacy and Bioallied Sciences.[1] This work aligns with the growing trend in dentistry that promotes the use of natural extracts in endodontics. We would like to congratulate the authors for their commendable work in exploring the antimicrobial efficacy of three essential oils (EOs): lemongrass oil, basil oil, peppermint oil, and a tea mixture extract against endodontic pathogens. For this purpose, the authors proposed simple in vitro methods to evaluate minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), and minimum fungicidal concentrations (MFCs). However, some methodological concerns may need to be highlighted for the sake of clarity and reproducibility. Firstly, regarding the herbal products used, the authors provided information on their commercial origin but did not specify the concentrations tested or the volumes used. Additionally, it was unclear whether the EOs were mixed with a surfactant such as DMSO (Dimethyl Sulfoxide) or Tween 80 (Polysorbate 80), or used alone. The use of these surfactants is crucial for improving bioavailability of the EOs and maintaining a homogeneous mixture with the bacterial inoculum, as the EOs are scarcely water-soluble.[2] Secondly, the authors utilized broth dilution method and subculturing technique to evaluate the antimicrobial activity of the herbal extract against several microorganisms as a quantitative approach. However, they didn’t specify the initial concentration of the bacterial inoculum tested in their study. Additionally, they did not mention the incubation conditions, such as temperature and incubation period, that are crucial for accurately interpreting results and ensuring reproducibility of the study. It is also important to highlight the necessity of proposing a qualitative approach, such as microscopy, when assessing the antimicrobial efficacy of an agent, as relying solely on culturing methods can be insufficient.[3] It would be appreciated if they provided precise numerical values for the MICs, MBCs, and MFCs corresponding to each microorganism for easier interpretation of the outcomes. While acknowledging the efforts and dedication involved in this study, additional methodological details would have been helpful for gaining a more thorough understanding of the results. Furthermore, these details would allow for more accurate comparisons across studies in the literature. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Complete elimination of microorganisms from the root canals is the important key for the successful endodontic treatment. Constant emergence of resistant strains and adverse effects of synthetic drugs has led to the search of effective herbal alternatives. Nutmeg (Myristica fragrans) is one such spice used for its various medicinal activities. To evaluate the antimicrobial effect of M. fragrans on common endodontic pathogens of primary tooth. Essential oil of nutmeg was extracted by hydrodistillation method, and its phytoconstituents were determined by thin-layer chromatography (TLC), high-performance TLC, and gas chromatography-mass spectrometry analysis. Minimum inhibitory concentration of essential oil against standard strains of common endodontic pathogens (Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, Candida albicans, Lactobacillus casei, Actinomyces viscosus, Prevotella intermedia, and Porphyromonas gingivalis) was determined by serial tube dilution method. Essential oil of M. fragrans was effective against all tested endodontic microorganisms. The active components of essential oil of nutmeg such as myristicin, myristic acid, trimyristin, elemicin, and safrole have good antimicrobial activity and are effective against endodontic microorganisms. M. fragrans can be used as an effective medicament in the treatment of endodontic infections.

Infection caused by microorganisms play a crucial role in the induction of inflammation of pulpal as well as the periapical tissues. Factors like improper disinfection or obturation of the root canal space contributes to the failure of the root canal treatment. The aim of the study was to modify the contents of MTA-based sealer with nanoparticles and check for its antibacterial efficacy against E. faecalis. Silver nanoparticles (10 nm) were incorporated in MTA based sealer at various concentrations to form the test product. The antibacterial efficacy of the modified sealer was tested by well diffusion test on E. faecalis. The zone of inhibition (mm) was checked for each test product. Analysis of the results showed significant diameters of zones of inhibition (mm) as compared to sealer without nanoparticles. The zone of inhibition increased with the increase in the concentration of silver nanoparticles. The silver nanoparticle incorporated sealer can be used in the clinical setup to prevent reinfection of the root canal system and ensure the success of the root canal treatment.

Antibacterial Efficacy and Discoloration Potential of Endodontic Topical Antibiotics

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.

Antimicrobial Effect of Triclosan and Triclosan with Gantrez on Five Common Endodontic Pathogens

An Agar Diffusion Comparison of the Antimicrobial Effect of Calcium Hydroxide at Five Different Concentrations with Three Different Vehicles

The aim of this in vitro study was to evaluate the antimicrobial action of BioPure MTAD (Dentsply Tulsa Dental, Johnson City, TN), Tetraclean, Cloreximid (a mixture of Chlorhexidine (CHX) digluconate and Cetrimide), and 5.25% NaOCl (Ogna Laboratori Farmaceutici, Milano, Italy) against selected endodontic pathogens (Enterococcus faecalis, Porphyromonas gingivalis, and Prevotella intermedia). The agar plate diffusion procedure was used to observe the antimibrobial activity of irrigants. Statistical analysis revealed significant effects of the different irrigants on the bacteria colonies. Treatment with 5.25% NaOCl induced a larger zone of microbial inhibition in Prevotella intermedia and Porphyromonas gingivalis (Tukey HSD post-test, P = 0.0001) when compare to MTAD, Tetraclean and CHX. Anyway, MTAD and Tetraclean were more effective to inhibit bacterial growth compared to CHX (P < 0.0001, Tukey HSD post-test). Furthermore, post hoc analysis revealed that MTAD and Tetraclean induced the largest zone of microbial inhibition of Enterococcus faecalis cultured under both aerobic and anaerobic conditions, when compared with 2% CHX and NaOCl (P < 0.0001, Tukey HSD post-test). The control group showed no microbial inhibition. 5.25% NaOCl showed a high antimicrobial activity against anaerobic bacteria. MTAD and Tetraclean showed a high action against both, strictly anaerobic and facultative anaerobic bacteria. Chlorexidine + Cetrimide (Cloreximid) showed the lowest antibacterial activity against both, facultative and strictly anaerobic bacteria tested.

Aims and Objectives:The principal goal of endodontics is the prevention of periapical infection. Acute and chronic apical periodontitis occur due to the persistence of pathogenic microorganisms such as Enterococcus faecalis and Candida albicans harboring the root canal systems of the teeth. The concept of the use of probiotics in addressing endodontic disease is new and has not been studied adequately. On the basis of the success of probiotics in periodontal treatment, this preliminary work was performed (a) to evaluate the antibacterial efficacy of probiotics against common endodontic pathogens, i.e. E. faecalis and C. albicans, and (b) to evaluate the potential use of probiotic therapy as an additive in endodontic treatment procedures.Materials and Methods:Two commercial probiotics were selected and evaluated based upon the numbers and concentration of organisms. Pathogenic test organisms were C. albicans (ATCC 10231) and E. faecalis (ATCC 29212). Phase 1 of the study was conducted by agar cup method test to evaluate the antibacterial activity of the selected probiotics against E. faecalis and C. albicans by measuring zones of inhibition (ZOI) in mm. Microorganisms from probiotic samples were isolated following manufacturer's instructions. Pathogenic organisms were set to a 0.1 McFarland standard challenge. Circular wells of 8 mm diameter were punched in each of the poured plates. Appropriately diluted test samples were added to the above-punched wells. The volume of the solution added to each well was 100 μl. The plates were incubated in an upright position at 37°C for 24 hours under aerobic conditions. Post incubation, ZOI was measured (mm). Phase 2 was conducted by mixing 9 ml of 30% poloxamer 407 and de Man, Rogosa and Sharpe (MRS) broth in a test tube with 500 μl of either E. faecalis or C. albicans set at an optical density (OD) of 0.252, together with 500 μl of test probiotic strain, set at a respective OD. Samples were then incubated at 37°C for 48 hours, followed by serial dilutions by 1 ml till 108. This was done to calculate colony forming units (CFU)/ml counts. Controls used were endodontic pathogens in 30% poloxamer with MRS broth without any probiotic group.Results:Probiotic groups showed inhibitory activity against E. faecalis by the agar cup method, whereas there was no effect on C. albicans. In the biofilm stage, both the test groups had an antibacterial effect on pathogenic organisms.Conclusion:This study suggests that probiotic organisms of the species Lactobacillus and Bifidobacterium are effective for preventing the growth of E. faecalis and C. albicansin vitro. Because probiotics are available in varied compositions and concentrations, further evaluation for their role in treating endodontic infection is suggested and warranted. In addition, the study suggested that poloxamer 407 could be utilized as an ideal delivery vehicle for probiotics for use as a potential endodontic intracanal medicament.

Successful endodontic therapy requires total debridement as well as complete obturation of the root canal to the cemento-dentinal junction. The goal of this study was to investigate the feasibility of using quantitative fluorescence spectroscopy for the detection and localization of pathological dentin, pulpal remnants, and microorganisms within the root canal. Specific aims were to identify: 1) characteristic excitation/emission spectra for healthy dentin, decayed dentin, enamel, and pulp; 2) the potential of specific spectral data for differentiating between these tissues; and 3) the potential of spectral data for detecting the presence and identifying four common endodontic pathogens. Fluorescence spectra were determined in the tissues of permanent human teeth, extirpated healthy and necrotic pulps, and four endodontic pathogens. Excitation/emission spectra were collected at 366 nm, 405 nm, and 440 nm excitation. Marked differences in spectral signatures between the different tissues under investigation were observed. We postulate that the differences in fluorescence spectra of decayed vs. healthy dentin are due to the loss of mineralized tissue components and increased organic presence and water in these tissues. Pulpal tissue showed distinctly different fluorescence spectra from healthy and decayed dentin, providing a basis for differentiating between tissue categories. Each bacterial species demonstrated distinct spectral emission patterns.

The purpose of endodontic therapy is to preserve the patient's natural teeth without compromising the patient's local or systemic health. Calcium hydroxide has been included in several materials and antimicrobial formulations that are used in several treatment modalities in endodontics, such as inter-appointment intracanal medicaments. The purpose of this article was to review the antimicrobial properties of calcium hydroxide in endodontics. Calcium hydroxide has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. Calcium hydroxide has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also a valuable anti-endotoxin agent. However, its effect on microbial biofilms is controversial.

The goal of endodontic treatment is the prevention and control of pulpal and periradicular infections. Calcium hydroxide (Ca(OH)2) has been widely used in endodontics as an intracanal medicament to eliminate the remaining microorganisms after chemomechanical preparation. The purpose of this article is to review the antimicrobial properties of Ca(OH)2 as an intracanal medicament in root canal treatment. The first part of this review details the characteristics of Ca(OH)2 and summarizes the results of in vitro studies related to its antimicrobial effect. The antimicrobial effect of Ca(OH)2 results from the release of hydroxyl ions when it comes into contact with aqueous fluids. Ca(OH)2 has a wide range of antimicrobial effects against common endodontic pathogens, but is less effective against Enterococcus faecalis and Candida albicans. The addition of vehicles or other agents might contribute to the antimicrobial effect of Ca(OH)2.

Antimicrobial Efficacy of Medicated Root Canal Filling Materials

Periapical bone resorption occurs following infection of the dental pulp and is mediated mainly by IL-1alpha in the murine model. The production and activity of IL-1alpha is modulated by a network of regulatory cytokines, including those produced by Th1 (pro-inflammatory) and Th2 (anti-inflammatory) subset T cells. This study was designed to assess the functional role of the Th2-type cytokines IL-4 and IL-10 in infection-stimulated bone resorption in vivo. The dental pulps of the first molars were exposed and infected with a mixture of four common endodontic pathogens, and bone destruction was determined by micro-computed tomography at sacrifice on day 21. The results demonstrate that IL-10(-/-) mice had significantly greater infection-stimulated bone resorption in vivo compared with wild-type mice (p < 0.001), whereas IL-4(-/-) exhibited no increased resorption. IL-10(-/-) had markedly elevated IL-1alpha production within periapical inflammatory tissues (>10-fold) compared with wild type (p < 0.01), whereas IL-4(-/-) exhibited decreased IL-1alpha production (p < 0.05). IL-10 also suppressed IL-1alpha production by macrophages in a dose-dependent fashion in vitro, whereas IL-4 had weak and variable effects. We conclude that IL-10, but not IL-4, is an important endogenous suppressor of infection-stimulated bone resorption in vivo, likely acting via inhibition of IL-1alpha expression.