In vitro susceptibility of Candida albicans to four disinfectants and their combinations

Synergistic Bactericidal Effects of Quaternary Ammonium Compounds with Essential Oil Constituents

Antimicrobial tolerance is a significant concern in the food industry, as it poses risks to food safety and public health. To overcome this challenge, synergistic combinations of antimicrobials have emerged as a potential solution. In this study, the combinations of two essential oil constituents (EOCs), namely carvacrol (CAR) and eugenol (EUG), with the quaternary ammonium compounds (QACs) benzalkonium chloride (BAC) and didecyldimethylammonium chloride (DDAC) were evaluated for their antimicrobial effects against Escherichia coli and Bacillus cereus, two common foodborne bacteria. The checkerboard assay was employed to determine the fractional inhibitory concentration index (FICI) and the fractional bactericidal concentration index (FBCI), indicating the presence of bactericidal, but not bacteriostatic, synergy in all QAC-EOC combinations. Bactericidal synergism was clearly supported by Bliss independence analysis. The bactericidal activity of the promising synergistic combinations was further validated by time-kill curves, achieving a >4-log10 reduction of initial bacterial load, which is significant compared to typical industry standards. The combinations containing DDAC showed the highest efficiency, resulting in the eradication of bacterial population in less than 2-4 h. These findings emphasize the importance of considering both bacteriostatic and bactericidal effects when evaluating antimicrobial combinations and the potential of EOC-QAC combinations for sanitization and disinfection in the food industry.

Expert consensus on irrigation and intracanal medication in root canal therapy

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment. However, irrigant selection or irrigation procedures are far from clear. The vapor lock effect in the apical region has yet to be solved, impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes. Additionally, ambiguous clinical indications for root canal medication and non-standardized dressing protocols must be clarified. Inappropriate intracanal medication may present side effects and jeopardize the therapeutic outcomes. Indeed, clinicians have been aware of these concerns for years. Based on the current evidence of studies, this article reviews the properties of various irrigants and intracanal medicaments and elucidates their effectiveness and interactions. The evolution of different kinetic irrigation methods, their effects, limitations, the paradigm shift, current indications, and effective operational procedures regarding intracanal medication are also discussed. This expert consensus aims to establish the clinical operation guidelines for root canal irrigation and a position statement on intracanal medication, thus facilitating a better understanding of infection control, standardizing clinical practice, and ultimately improving the success of endodontic therapy.

Comparative evaluation of antifungal activity of Sodium Hypochlorite, Calcium Hypochlorite and modified Salt Solution associated with passive ultrasonic irrigation against Candida albicans - An In-Vitro study

Aim

The study evaluated the antifungal activity of sodium hypochlorite (NaOCl), calcium hypochlorite (Ca(OCl)2), and modified salt solution (MSS) assisted with passive ultrasonic irrigation against Candida albicans.

Materials and Methods

One hundred and thirty-six single-rooted premolars were decoronated and enlarged up to a file #45, autoclaved, inoculated with C. albicans, and incubated for 72 h. The samples were randomly distributed into eight groups (n = 17) according to the protocol for decontamination G1: No treatment, G2: Distilled water (DW), G3: 2.5% NaOCl, G4: 2.5% NaOCl + ultrasonic activation (US), G5: 2.5% Ca(OCl)2, G6: 2.5% Ca(OCl)2 + US, G7: MSS, G8: MSS + US. Microbiological testing (Colony forming Unit [CFU] counting) was performed before and after the treatment.

Statistical Analysis

Data were subjected to the one-way analysis of variance followed by the Tukey's post hoc test (P < 0.05).

Results and Conclusion

Groups 1 and 2 showed the highest mean contamination (5.41 and 4.31 log10 CFU/mL, respectively), which was statistically different from all the other groups (P < 0.001). G4 showed the lowest mean contamination (0.24 log10 CFU/mL) with statistically significant value (P < 0.001). 2.5% NaOCl with ultrasonic activation can aid in significant fungal reduction. Ultrasonic activation of 2.5% NaOCl, 2.5% Ca(OCl)2, and MSS was also found to have improved antifungal activity against C. albicans.

Efficacy of Bioceramic and Calcium Hydroxide-Based Root Canal Sealers against Pathogenic Endodontic Biofilms: An In vitro Study

Background

Complete eradication of root canal pathogens cannot be predictably achieved by chemomechanical preparation and root canal disinfection. Therefore, an obturation material that has superior antimicrobial activity and sealing ability is required to inactivate residual microbes and prevent them from reentering the root canal system. Recently developed bioceramic root canal sealers are hydraulic cement which form calcium hydroxide during the hydration process. Like calcium hydroxide sealers, they exert an antimicrobial effect by releasing hydroxyl ions and increasing the pH.

Objective

The objective of this study was to evaluate and compare the antimicrobial activity of a calcium hydroxide-based sealer and two bioceramic sealers against Porphyromonas gingivalis, Enterococcus faecalis, and Candida albicans biofilms.

Materials and Methods

The sealers were dissolved in sterile saline to obtain supernatants. Biofilm formation assays, colony counting, and real-time polymerase chain reaction (PCR) were performed to evaluate the antimicrobial activity of each supernatant. The data were analyzed using one-way analysis of variance.

Results

All sealers exerted effects against all three microbial biofilms. The biofilm formation assays showed that the bioceramic sealers were more effective against P. gingivalis and E. faecalis biofilms. In contrast, colony counting and real-time PCR showed that the calcium hydroxide sealer was significantly more effective than the bioceramic sealers. All tests showed that the calcium hydroxide sealer was more effective against C. albicans, with the colony count and real-time PCR results showing statistically significant differences.

Conclusion

The calcium hydroxide-based sealer was more effective than the bioceramic sealers in eradicating pathogenic root canal biofilms.

Efficacy of chitosan paste as intracanal medication against Enterococcus faecalis and Candida albicans biofilm compared with calcium hydroxide in an in vitro root canal infection model

Background

Enterococcus faecalis and Candida albicans are frequently found in persistent endodontic infection and could remain in dentinal tubules despite intracanal medication with calcium hydroxide (Ca(OH)₂), a commonly used medication. Thus, an effective and safe antimicrobial medication against such refractory infection is necessary in endodontic retreatment, so we aimed to test the efficacy of chitosan paste against these microorganisms compared with Ca(OH)₂ in root canals of extracted human teeth.

Methods

Thirty-six sterilized human root samples prepared from extracted premolars and upper maxillary incisors were infected with E. faecalis for 14 days, while 32 were infected with C. albicans for 48 h, for mature biofilm formation. The samples were assigned to 6 groups of intracanal medications: Group 1: no medication (negative control); Group 2: 20% Polyethylene glycol (PEG); Group 3: 20% Propylene glycol (PG); Group 4: Ca(OH)₂; Group 5: Chitosan + PEG; and Group 6: Chitosan + PG. After 7 days, intracanal surface dentin was harvested using Protaper next, resuspended, serially diluted and spread on Brain–Heart-Infusion agar (for E. faecalis) and Yeast Extract-Peptone-Dextrose agar (for C. albicans) for colony count. Antimicrobial efficacy was determined as percentage of remaining colony forming unit (CFUs) relative to negative control and analyzed using One-way ANOVA and post-hoc Games-Howell test. The significance level was set at 0.05.

Results

For E. faecalis, chitosan + PG had significantly higher antibacterial activity than Ca(OH)₂ (P = 0.039). Chitosan + PEG and chitosan + PG medication significantly reduced viable bacteria compared with negative control, PEG and PG (P = 0.001, 0.003, 0.024, respectively for chitosan + PEG; P = 0.002, 0.003, 0.014, respectively for chitosan + PG). For C.albicans, chitosan + PEG and chitosan + PG were not significantly different from Ca(OH)₂. However, Chitosan + PEG and chitosan + PG, but not Ca(OH)₂, showed a significantly lower level of remaining CFUs compared with negative control (P = 0.013 and 0.005, respectively).

Conclusion

Chitosan paste showed better efficacy in reducing viable E. faecalis biofilm when compared to Ca(OH)₂ after 7-day intracanal medication in this in vitro root canal model. It could also significantly reduce viable C. albicans, but was not significantly different from Ca(OH)₂.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02385-x.

Influence of vehicle for calcium hydroxide on postoperative pain: a scoping review

This review aims to identify the influence of the vehicle and its concentration used to carry calcium hydroxide (Ca(OH)₂) medicament on postoperative pain.

The protocol for this review was registered in the open science framework (Registration DOI-10.17605/OSF.IO/4Y8A9) and followed the guidelines provided by the Joanna Briggs Institute. Reporting was based on the preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR). Literature screening and searches were performed on PubMed/Medline, Scopus, and EBSCO hosts. Furthermore, additional records were manually analyzed using various sources. The selected studies were published in English and included the use of any vehicle adjunct to Ca(OH)₂ to evaluate postoperative pain using qualitative and quantitative pain assessment tools. Descriptive analysis was conducted to review the study design, vehicle elements, and their effects.

A preliminary search yielded 7584 studies, of which 10 were included. According to the data collected, the most commonly used Ca(OH)₂ vehicles were chlorhexidine (CHX), normal saline, and camphorated paramonochlorophenol/glycerine (CPMC/glycerine), which had a significant effect on postoperative pain. Among the included studies, six evaluated the effect of CHX as a vehicle. It was observed that a higher concentration of the vehicle (2%) showed a favorable response in reducing postoperative pain.

A majority of studies have validated a positive consequence of using a vehicle on postoperative pain. Although higher vehicle concentrations were found to alter postoperative pain levels, the data were insufficient to draw a firm conclusion. Our scoping review indicates that further clinical studies should focus on using different vehicles at various concentrations and application times to check for feasible and safe exposure in addition to providing pain relief.

Effectiveness of D,L-2-hydroxyisocaproic acid (HICA) and alpha-mangostin against endodontopathogenic microorganisms in a multispecies bacterial-fungal biofilm in an ex vivo tooth model

AIM

To develop a defined multispecies root canal biofilm model ex vivo, and to perform viable compositional analysis following D,L-2-hydroxyisocaproic acid (HICA), alpha-mangostin, Calcicur^® , and Odontopaste^® exposure.

METHODOLOGY

Time-kill assays were conducted in vitro using HICA, alpha-mangostin, Calcicur^® , Odontopaste^® , and saline solution on the planktonic cultures of C. albicans, E. faecalis, L. rhamnosus, and S. gordonii. Human root dentine blocks were prepared (n = 100) ex vivo, and multispecies suspensions containing each of 1.5 × 10⁸  CFU/mL C. albicans, E. faecalis, L. rhamnosus, and S. gordonii in brain heart infusion (BHI) were incubated within the root canals for 21 days. Canals (n = 20/group) were then exposed to medicaments for 7 days. Samples taken from the inner (first 0.1 mm) and deeper (second 0.1 mm) dentine by drilling with Ash Steel Burs No. 5 and No. 6, and residual roots were cultured in broth for 24 h. Cell growth was detected by spectrophotometry and confirmed by culture on agar. The other set of inner dentine, deeper dentine, and residual root samples were sonicated, and then exposed with 50 μM PMA before DNA was extracted using the QIAamp DNA mini kit. Real-time quantitative PCR was performed to determine the biofilm composition as well as the number of live and total cells remaining in the biofilm following each treatment. The OD data were analysed with Kruskal-Wallis and Friedman with Wilcoxon signed-rank test between and within groups, respectively, agar culture and qPCR data with Pearson chi-square with Mann-Whitney and Cochran with McNemar tests, respectively (p < .0001).

RESULTS

Time-kill assays revealed that HICA and Calcicur^® killed all planktonic organisms within 24 h, whilst alpha-mangostin killed the organisms within 72 h. However, Odontopaste^® was a slow-killing agent: 10 cells of planktonic organisms survived after exposure to the agent for 7 days. The ex vivo tooth model demonstrated that HICA and alpha-mangostin significantly inhibited the cell growth in all sampling depths (p < .0001). All species-specific data revealed the effectiveness of each medicament on the biofilm composition.

CONCLUSIONS

D,L-2-hydroxyisocaproic acid and alpha-mangostin had antimicrobial activity against multispecies bacterial-fungal biofilms.

Antibacterial Activity of Sodium Hypochlorite Gel versus Different Types of Root Canal Medicaments Using Agar Diffusion Test: An In Vitro Comparative Study

Aim

This study aimed to evaluate the antibacterial effect of sodium hypochlorite gel and four types of intracanal medicaments.

Materials and Methods

The agar diffusion method was used to evaluate the antibacterial effect of five medicaments (sodium hypochlorite gel (NaOCl), chlorhexidine gel (CHX), calcium hydroxide paste (CH), Ledermix, and Diapex plus) against Enterococcus faecalis (E. faecalis), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). The zone of inhibition around each medicament was measured in millimeters, after 48 hours of incubation at 37°C. The antibacterial effects of medicaments against each microbial strain and the sensitivity of microorganisms towards each medicament were compared using the one-way ANOVA and Games–Howell post hoc tests. The level of significance was set to p < 0.05.

Results

All medicaments showed variable inhibition zones for all bacterial strains except Diapex Plus which showed no antibacterial activity. NaOCl gel exhibited the most significant inhibition zones for all bacterial strains followed by CHX gel, Ledermix, and CH. However, the effect of CHX and CH paste against S. aureus was statistically similar, while the effect of CH against E. faecalis was significantly higher than the Ledermix.

Conclusion

Sodium hypochlorite gel displayed the highest antibacterial activity among tested medicaments and can be recommended as a potent intracanal medicament. Chlorhexidine gel showed a significantly higher antibacterial effect when compared with Ledermix and calcium hydroxide. Calcium hydroxide demonstrated stronger antibacterial activity against E. faecalis than Ledermix. Diapex Plus exhibited no antibacterial effect.

Effects of cold atmospheric pressure plasma and disinfecting agents on Candida albicans in root canals of extracted human teeth

Reinfection in endodontically treated teeth is linked to the complexity of the root canal system, which is problematic to reach with conventional disinfection methods. As plasma is expected to have the ability to sanitize narrow areas, the aim of this study was to analyze the effect of cold atmospheric pressure plasma (CAP) on Candida albicans in root canals of extracted human teeth. CAP was applied as mono treatment and in combination with standard endodontic disinfectants (sodium hypochlorite, chlorhexidine and octenidine). Disinfection efficiency was evaluated as reduction of the logarithm of colony forming units per milliliter (log₁₀ CFU/mL) supported by scanning electron microscopy as imaging technique. Plasma alone showed the highest reduction of log₁₀ CFU, suggesting the best disinfection properties of all tested agents.

The effects of various irrigation protocols on root canal wall adaptation and apical microleakage in primary teeth

Objective: The objective of this study is to evaluate the wall adaptation and apical microleakage values following the application of various irrigation protocols in primary teeth.Material and methods: For the two parts of the study, extracted upper incisor primary teeth were randomly included to the 1% sodium hypochlorite (NaOCl), 10% ethylenediaminetetraacetic acid (EDTA)+1% NaOCl, 6% citric acid (CA)+1% NaOCl and 0.9% physiological saline (PS) groups. Canal wall adaptation and apical microleakage were assessed by scanning electron microscopy (SEM) and stereomicroscope, respectively.Results: 6% CA + 1% NaOCl group was found to be the most successful irrigation protocol in providing strong canal wall adaptation and less apical microleakage, followed by 10% EDTA +1% NaOCl. 6% CA +1% NaOCl was significantly superior regarding apical microleakage (p < .05).Conclusions: Due to the ability to provide appropriate changes in the root canal walls to make a well-adapted and leak-proof canal filling, 6% CA + 1% NaOCl can be recommended as an irrigation protocol in primary teeth.

Candida albicans Biofilm Heterogeneity and Tolerance of Clinical Isolates: Implications for Secondary Endodontic Infections

Aim: Endodontic infections are caused by the invasion of various microorganisms into the root canal system. Candida albicans is a biofilm forming yeast and the most prevalent eukaryotic microorganism in endodontic infections. In this study we investigated the ability of C. albicans to tolerate treatment with standard endodontic irrigants NaOCl (sodium hypochlorite), ethylenediaminetetraacetic acid (EDTA) and a combination thereof. We hypothesized that biofilm formed from a panel of clinical isolates differentially tolerate disinfectant regimens, and this may have implications for secondary endodontic infections. Methodology: Mature C. albicans biofilms were formed from 30 laboratory and oral clinical isolates and treated with either 3% NaOCl, 17% EDTA or a sequential treatment of 3% NaOCl followed by 17% EDTA for 5 min. Biofilms were then washed, media replenished and cells reincubated for an additional 24, 48 and 72 h at 37 °C. Regrowth was quantified using metabolic reduction, electrical impedance, biofilm biomass and microscopy at 0, 24, 48 and 72 h. Results: Microscopic analysis and viability readings revealed a significant initial killing effect by NaOCl, followed by a time dependent significant regrowth of C. albicans, but with inter-strain variability. In contrast to NaOCl, there was a continuous reduction in viability after EDTA treatment. Moreover, EDTA significantly inhibited regrowth after NaOCl treatment, though viable cells were still observed. Conclusions: Our results indicate that different C. albicans biofilm phenotypes grown in a non-complex surface topography have the potential to differentially tolerate standard endodontic irrigation protocols. This is the first study to report a strain dependent impact on efficacy of endodontic irrigants. Its suggested that within the complex topography of the root canal, a more difficult antimicrobial challenge, that existing endodontic irrigant regimens permit cells to regrow and drive secondary infections.

Antimicrobial Activity of Methanolic Extracts of Myrtus Communis L. and Eucalyptus Galbie and their Combination with Calcium Hydroxide Powder against Enterococcus Faecalis

Statement of the Problem:

The goal of endodontic therapy is the reduction or elimination of microorganisms from the root canal system. The use of intracanal medicament between treatment appointments is recommended in order to eliminate any remainang microorganisms in the pulp space.

Purpose:

The aim of the present study was to investigate the antimicrobial activity of methanolic extracts of Myrtus communis L. and Eucalyptus galbie, their combination with calcium hydroxide powder; combination of calcium hydroxide powder with water, and ready-to-use calcium hydroxide paste with iodoform; against Enterococcus faecalis.

Materials and Method:

In this experimental study, after gathering the plants, their methanolic extracts were obtained by masceration method. The diameters of inhibition zone of all mentioned materials were determined by agar diffusion test. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC); and anti biofilm effect of the materials that showed antibacterial effect in agar diffusion test, were then evaluated by tube dilution test, and microtiter plate assay followed by colorimetric crystal violet methods, respectively.

Results:

After 48 hours, both herbal extracts showed antimicrobial effect. However, combination of calcium hydroxide with extracts produced no zone of inhibition. The mean inhibition zone of Eucalyptus extract was more than that of Myrtus. However, the results of ANOVA test, showed that there was no significant difference between the antibacterial effect of Eucalyptus galbie, Myrtus communis L. and positive control (Cefoxitin) (p Value= 0.987). The MIC for both extracts were 12.5 mg/ml. MBC evaluation of the two methanolic extracts showed no bactericidal effect on Enterococcus faecalis. Based on ELISA analysis, biofilm formation in response to different sub-MIC concentrations of both extracts was scored as weak to moderate.

Conclusion:

The methanolic extracts of Eucalyptus galbie and Myrtus communis L. in combination with calcium hydroxide powder were not able to eliminate Enterococcus faecalis within 48 hours.

Antifungal and Synergistic Effects of the Ethyl Acetate Extract of Tanacetum vulgare (L.) Against Candida albicans

BACKGROUND With the continued demand for new, effective, and safe endodontic therapies, the aim of this study was assessment of efficiency of the ethyl acetate (EthOAc) extract of Tanacetum vulgare (L.) against Candida albicans. MATERIAL AND METHODS The antifungal effectiveness of the EthOAc extract of T. vulgare was determined using the agar disk diffusion method. The inhibition zones induced by the EthOAc extract were compared after 5 minutes, 60 minutes, and 24 hours to those induced by standard solutions (2% chlorhexidine, saturated calcium hydroxide, and 2% sodium hypochlorite). Statistical analysis of the results was performed using the Kruskal-Wallis test and one-way ANOVA. RESULTS The inhibition zone of chlorhexidine against C. albicans was 30.3-19.3 mm, but in combination with EthOAc extract (100 mg/mL) of T. vulgare, this inhibition was from 32.7-30 mm, indicating that this combination exerted a marked synergistic effect against C. albicans. The inhibition zone of sodium hypochlorite (69.7-65 mm) was higher than the inhibition zone of EthOAc extract and chlorhexidine. The combination of EthOAc extract with sodium hypochlorite resulted in a loss of antifungal activity. Furthermore, the activity of the EthOAc extract against C. albicans was decreased after mixing the extract with dentine at a concentration of 25 mg/50 µL (30.3-20.7 mm). The EthOAc extract did not show a genotoxic effect on lymphocyte cells. CONCLUSIONS The EthOAc extract of T. vulgare may be a useful tool to discover natural bioactive agents that have antifungal activity against C. albicans and could be used as endodontic therapies.

The effect of different irrigation protocols on smear layer removal in root canals of primary teeth: a SEM study

OBJECTIVE

The purpose of this study was to compare the efficacy of different irrigation protocols on smear layer removal in root canals of primary teeth by scanning electron microscopy (SEM).

MATERIAL AND METHODS

The study was conducted with 40 extracted maxillary primary incisor teeth divided into four groups (n = 10) as 1% sodium hypochlorite (NaOCl), 10% ethylenediaminetetraacetic acid (EDTA)+1% NaOCl, 6% citric acid (CA)+1% NaOCl, and 0.9% physiological saline (PS). After the irrigation procedures, root canal walls were examined by SEM and the efficacies of irrigation solutions in smear layer removal were scored and compared. Data were analyzed using Kruskal-Wallis, Friedman and Siegel Castellan tests.

RESULTS

The smear layer removal was found to be statistically more effective in groups of 10% EDTA + 1% NaOCl and 6% CA + 1% NaOCl when compared with the other groups (p < .05). Smear removal efficacy was statistically significantly higher in coronal and medium thirds when compared with the apical regions in the experimental groups.

CONCLUSIONS

It was concluded that 10% EDTA + 1% NaOCl and 6% CA + 1% NaOCl could be alternative irrigation protocols regarding smear layer removal. However, due to the absence of erosive dentinal changes, it might be suggested that using 6% CA + 1% NaOCl can be recommended compared to 10% EDTA + 1% NaOCl in primary root canals.

Unprepared root canal surface areas: causes, clinical implications, and therapeutic strategies

Chemomechanical preparation is intended to clean, disinfect, and shape the root canal. This step is of utmost importance during treatment of infected teeth with apical periodontitis, because treatment outcome depends on how effectively the clinician eliminates bacteria, their products, and necrotic tissue that would serve as substrate for bacterial regrowth. Nonetheless, curvatures and complex internal anatomical variations of the root canal system can pose a high degree of difficulty in reaching these goals. In infected teeth, bacteria may persist not only in difficult-to-reach areas such as isthmuses, ramifications, dentinal tubules, and recesses from C-shaped or oval/flattened canals, but also in areas of the main canal wall that remain untouched by instruments. If bacteria withstand chemomechanical procedures, there is an augmented risk for post-treatment apical periodontitis. This article discloses the reasons why some areas remain unprepared by instruments and discusses strategies to circumvent this issue and enhance infection control during endodontic treatment/retreatment of teeth with apical periodontitis.

Consideration of the Therapeutic Potential of Irrigants in Endodontic Therapy

The main objective of endodontic treatment is to remove vital and necrotic remnants of pulp tissue and microorganisms and their toxic products from the root canal. During chemo-mechanical endodontic preparation, a smear layer is formed on the wall of the canals. Due to an inability to remove all tissue remnants and the smear layer from the root canal by mechanical instrumentation, it is necessary to use irrigation to ensure sufficient cleaning and disinfection of the largest part of the root canalicular system. The most commonly used irrigants are sodium hypochlorite (Na-OCl), ethylenediaminetetraacetic acid (EDTA), citric acid and chlorhexidine (CHX). Recently, the irrigants QMix and MTAD have been introduced to the market. They are a mixture of different components having antimicrobial, organolytic and mineralytic effects on canal detritus and the smear layer. This review article investigates irrigants in terms of the nature of their effect, their efficiency, optimal concentration, and method of use, and the interactions between the irrigants most commonly used in endodontic therapy are discussed, with special emphasis on QMix and MTAD.

Antifungal Efficacy and the Mechanical Properties of Soft Liners against Candida albicans after the Incorporation of Garlic and Neem: An In vitro Study

Objectives:

To evaluate the in vitro growth inhibition of Candida albicans, in the soft-liner material and Shore A hardness from resin-based denture soft lining materials modified by neem or garlic incorporation.

Materials and Methods:

Resin discs were prepared with poly methyl methacrylate (PMMA) and soft liners incorporated with varying concentrations of neem or garlic. For antifungal activity, resin discs were placed on agar plates inoculated with C. albicans and were evaluated after 2, 4, and 7 days using the streaking method. The hardness of the PMMA was evaluated with the use of Shore A at 2, 4, and 7 days. Data were statistically processed by SPSS software (IBM Company, Chicago, USA) using Kruskal–Wallis test, and post hoc comparisons were done using Dunn's test. P <0.05 was considered statistically significant.

Results:

Neem and garlic added to PMMA soft liner had an inhibitory effect on C. albicans. Both the neem and garlic when added showed positive results against C. albicans when compared to the control group. The soft liner hardness increased statistically by time but not for the different plant extract concentrations.

Conclusions:

Within the limitations of this in vitro study, it was found that neem and garlic can be used as an additive to tissue conditioner to reduce the adherence of C. albicans without significantly affecting the hardness of the heat-polymerized acrylic resin.

Antimicrobial activity of Psidium cattleianum associated with calcium hydroxide against Enterococcus faecalis and Candida albicans: an in vitro study

OBJECTIVE

Evaluate, in vitro, the antimicrobial activity of Psidium cattleianum leaf extracts combined with calcium hydroxide against Enterococcus faecalis and Candida albicans biofilm.

MATERIALS AND METHODS

Dentin specimens obtained from extracted bovine incisors were infected during 14 days with E. faecalis ATCC 29212 and C. albicans ATCC 10231. The specimens were filled with calcium hydroxide pastes prepared with the following vehicles: Psidium cattleianum ethanolic, Psidium cattleianum propylene glycolic, distilled water, and saline as control. After 24 h, 3, 7, and 14 days, the canals were irrigated with sterile saline and dried. Dentin samples were collected from the canals with burs of increasing diameters. To determine the number of colony-forming units (CFU), samples were inoculated onto BHI agar supplemented with yeast extract (0.5%), at 37 °C, for 48 h, in CO₂ enriched atmosphere. Comparisons among the groups for the variation factors were performed by ANOVA and Tukey's test.

RESULTS

Ethanolic and propylene glycolic extracts showed significantly higher antimicrobial activity against E. faecalis (p < 0.01) when compared with distilled water. The ethanolic extract exhibited in 24 h the same antibacterial activity that propylene glycolic extract and distilled water after 7 and 14 days. For C. albicans, all were effective in reducing the number of CFU at all periods.

CONCLUSION

The P. cattleianum ethanolic extract presented the fastest and highest antimicrobial activity against E. faecalis, significantly reducing the microbial load in 24 h. All medications were effective against C. albicans.

CLINICAL RELEVANCE

The antibacterial potential of P. cattleianum and its biological compatibility associated with calcium hydroxide indicate promising applications in the field of dentistry.

Comparative Evaluation of Antimicrobial Efficacy of Silver Nanoparticles and 2% Chlorhexidine Gluconate When Used Alone and in Combination Assessed Using Agar Diffusion Method: An In vitro Study

Context:

Silver nanoparticle (AgNP) is a potent antimicrobial that is widely used in several fields of medicine. Chlorhexidine (CHX) gluconate is a well-known agent used in dentistry to eliminate oral microbial flora.

Aims:

The aim of this study is to evaluate the efficacy of AgNPs, 2% CHX gluconate, and the combination of two solutions against endodontic pathogens such as Enterococcus faecalis, Klebsiella pneumoniae, and Candida albicans. These organisms are frequently found in the root canal space and their persistence may lead to endodontic failure. The synergistic effect of the two solutions has been evaluated in this study. The antibiotic gentamycin was taken as the control group.

Settings and Design:

Agar well diffusion method was used and minimum inhibitory concentration of AgNP was found to be 15 μg/mL. AgNPs were synthesized from the aqueous plant extract of Cassia roxburghii. The combination of CHX-AgNP solution was stirred together by a glass rod. The values were tabulated and subjected to statistical analysis using the SPSS software version 20. One-way ANOVA test was used to compare within the groups and between groups. The level of significance was set at 5%.

Results:

CHX-AgNP combined solution exhibited the highest efficacy in comparison to these solutions used alone. They showed the highest efficacy against C. albicans among the three organisms tested.

Conclusion:

The present study demonstrates the antimicrobial efficacy of a novel mixture of CHX-AgNP solution, and it may be developed as a promising antimicrobial agent against endodontic flora.

Antifungal Effects of Synthetic Human Beta-defensin-3-C15 Peptide on Candida albicans-infected Root Dentin

INTRODUCTION

The aim of this study was to assess the antifungal efficacy of a synthetic human beta-defensin-3-C15 peptide (HBD3-C15) in Candida albicans-infected human root dentin.

METHODS

Standardized root dentin blocks were prepared (6-mm thick, 0.7-mm-wide canal) from single-rooted human permanent premolars and infected with C. albicans for 3 weeks. They were randomly divided into 4 groups (n = 8/group), and their canals were filled with calcium hydroxide (CH), HBD3-C15 peptide, or chlorhexidine digluconate (CHX, 2%) as disinfectants or saline as control. After 1 week of disinfection, dentinal debris were harvested at depths of 200 and 400 μm from the canal lumen, and incubated in Yeast broth for 72 hours at 37°C. Then, colony-forming units (CFU) were measured to assess the antifungal efficacy of each medicament and analyzed statistically.

RESULTS

All medicaments showed significantly lower CFU than saline (P < .05), and their antifungal efficacies were similar at both 200- and 400-μm tubular depths (P > .05). HBD3-C15 had similar antifungal efficacy to that of CHX at both depths (P > .05), and both medicaments had significantly lower CFU than CH at both depths (P < .05).

CONCLUSIONS

In this ex vivo model of C. albicans-infected human root dentin, the antifungal efficacy of synthetic HBD3-C15 was comparable with CHX.

Effect of conventional irrigation and photoactivated disinfection on Enterococcus faecalis in root canals: An in vitro study

Aims:

A study was done to evaluate the antimicrobial efficacy of sodium hypochlorite (NaOCl) and photoactivated disinfection (PAD) on Enterococcus faecalis.

Settings and Design:

Random sampling, in-vitro study.

Subjects and Methods:

Access opening and biomechanical preparation were performed on fifty freshly extracted mandibular second premolars. The specimens were sterilized; 15 μm of E. faecalis was inoculated into each canal and incubated at 36°C for 24 h. Later, specimens were randomly divided into two groups of fifty each and following procedures was carried out: (i) conventional irrigation with 2.25% NaOCl (ii) PAD using diode laser, and toluidine blue photosensitizer. Samples were collected from each canal using sterile paper points which were deposited in brain heart infusion broth, and microbiological evaluation was carried out.

Statistical Analysis Used:

Student's t-test was used to find the significant difference in the reduction of colony forming unit (CFU) between the groups.

Results:

The mean CFUs of the two groups showed statistically significant difference (P = 0.001). Improved antibacterial efficacy was seen with PAD group compared to conventional NAOCL irrigation.

Conclusions:

NaOCl alone was not effective in eliminating E. faecalis completely from the root canals. PAD compared to conventional irrigation showed the best results in removing E. faecalis from root canals.

Formulation and Evaluation of Sol-Gel Drug Delivery System for Intracanal pH Sensitive Controlled Delivery of Chlorhexidine

INTRODUCTION

Persistence of viable micro-organisms even after thorough chemomechanical debridement has been cited as a major cause for endodontic failure. Chlorhexidine is a drug, which has shown marked efficacy against Enterococcus faecalis and Candida spp., which are mostly accounted for endodontic failure and it has demonstrated high degree of substantivity to dentin by adsorption. Another issue with chlorhexidine and other intracanal medicaments is the excessive or premature peaking of the drug leading to possible side effects.

AIM

The objective of this experimental work undertaken was to formulate a pH sensitive sol-gel sustained drug delivery system containing chlorhexidine.

MATERIALS AND METHODS

The formulations were prepared using different concentrations of GELRITE^® (0.1% and 0.2%) and Chlorhexidine (0.1% and 0.2%). The prepared solutions were evaluated for pharmacological properties like sterility test, viscosity, drug content, drug release characteristics, drug excipient compatible study.

RESULTS

The drug excipient compatibility studies showed no interaction between the excipient and the active constituent. The microbial analysis showed good efficacy against the test micro-organisms and Minimum Inhibitory Concentration (MIC) values against Candida albicans (ATCC^® 14053™) was observed as 4 μl/ml for both formulation containing 0.1% and 0.2% of GELRITE^® Gellan (polymer). Whereas, MIC values against Enterococcus faecalis was observed to be 3.2 μl/ml and 6 μl/ml for formulation containing 0.1% and 0.2% of GELRITE^® Gellan (polymer) respectively.

CONCLUSION

From the present study, it could be successfully demonstrated that sol-gel formulations can be simple, easy to administer mode of intracanal drug delivery system. Localized pH changes present within the canal can trigger sol-gel conversion thereby releasing the drug in sustained manner with less toxicity and side effects.

Postoperative Pain and Flare-Ups: Comparison of Incidence Between Single and Multiple Visit Pulpectomy in Primary Molars

INTRODUCTION

Endodontic treatment performed in either single- or multiple visit can be followed by numerous short- and long term complications. One of the short term complications include postoperative pain and flare-ups. The ability to predict its prevalence and forewarn the patient may go some way towards enabling coping strategies and help dentist in pain management treatment decisions.

AIM

To compare the incidence and intensity of postoperative pain and flare-ups between single- and multiple visit pulpectomy in primary molars. Also, to correlate the preoperative status of the pulp to postoperative pain and flare-ups.

MATERIALS AND METHODS

Eighty primary molars indicated for pulpectomy were included in the study and divided into two groups. Tooth treated and preoperative status of the pulp vitality was recorded. All the conventional steps in pulpectomy were followed. Teeth in Group 1 (single visit pulpectomy) were obturated on the same visit. Teeth in Group 2 (multiple visit pulpectomy) were obturated in the subsequent appointment. The recording of postoperative pain, flare-ups, use of medication were done after 24 hours, seven days and one month.

RESULTS

Four cases in both the groups reported postoperative pain (10%) at 24 hour recall, p=0.74. One flare-up (2.5%) was recorded in each group p=0.67. None of the patients reported pain at seventh day and one month recall. Postoperative pain was recorded in five non-vital teeth (13.5%) and three vital teeth (6.9%). However, it was statistically not significant p=0.53.

CONCLUSION

From the perspective of our study there was a low incidence of postoperative pain. The majority of patients in both groups reported no pain or only minimal pain within 24 hours of treatment. There were no differences between single- and multi visit treatment protocols with respect to the incidence of postoperative pain. No significant correlation could be found between pulp vitality and the incidence of postoperative pain.

Experimental and Theoretical Investigation of Multispecies Oral Biofilm Resistance to Chlorhexidine Treatment

We investigate recovery of multispecies oral biofilms following chlorhexidine gluconate (CHX) and CHX with surface modifiers (CHX-Plus) treatment. Specifically, we examine the percentage of viable bacteria in the biofilms following their exposure to CHX and CHX-Plus for 1, 3, and 10 minutes, respectively. Before antimicrobial treatment, the biofilms are allowed to grow for three weeks. We find that (a). CHX-Plus kills bacteria in biofilms more effectively than the regular 2% CHX does, (b). cell continues to be killed for up to one week after exposure to the CHX solutions, (c). the biofilms start to recover after two weeks, the percentage of the viable bacteria recovers in the 1 and 3 minutes treatment groups but not in the 10 minutes treatment group after five weeks, and the biofilms fully return to the pretreatment levels after eight weeks. To understand the mechanism, a mathematical model for multiple bacterial phenotypes is developed, adopting the notion that bacterial persisters exist in the biofilms together with regulatory quorum sensing molecules and growth factor proteins. The model reveals the crucial role played by the persisters, quorum sensing molecules, and growth factors in biofilm recovery, accurately predicting the viable bacterial population after CHX treatment.

Antimicrobial efficacy of chlorhexidine as a root canal irrigant: a literature review

Use of an appropriate root canal irrigant is essential during endodontic treatment, due to the complex and unpredictable anatomy of the root canal system and limitations in the mechanical instrumentation techniques used to obtain a clean, bacteria-free canal. Several irrigants, such as sodium hypochlorite, chlorhexidine, hydrogen peroxide, and normal saline, have been proposed as canal system irrigants in endodontic treatment. The widely used endodontic irrigant chlorhexidine is a positively charged lipophilic/hydrophobic molecule that interacts with phospholipids and lipopolysaccharides on the bacterial cell membrane. In endodontics, its mode of antibacterial activity is determined by its concentration (0.2% or 2%). This article reviews findings from available endodontic studies on the antibacterial, antifungal, and antibiofilm activities of chlorhexidine.

β-lactam substituted polycyclic fused pyrrolidine/pyrrolizidine derivatives eradicate C. albicans in an ex vivo human dentinal tubule model by inhibiting sterol 14-α demethylase and cAMP pathway

BACKGROUND

Further quest for new anti-fungal compounds with proven mechanisms of action arises due to resistance and dose limiting toxicity of existing agents. Among the human fungal pathogens C. albicans predominate by infecting several sites in the body and in particular oral cavity and root canals of human tooth.

METHODS

In the present study, we screened a library of β-lactam substituted polycyclic fused pyrrolidine/pyrrolizidine compounds against Candida sp. Detailed molecular studies were carried out with the active compound 3 on C. albicans. Morphological damage and antibiofilm activity of compound 3 on C. albicans was studied using scanning electron microscopy (SEM). Biochemical evidence for membrane damage was studied using flow cytometry. In silico docking studies were carried out to elucidate the mechanism of action of compound 3. Further, the antifungal activity of compound 3 was evaluated in an ex vivo dentinal tubule infection model.

RESULTS

Screening data showed that several new compounds were active against Candida sp. Among them, Compound 3 was most potent and exerted time kill effect at 4h, post antifungal effect up to 6h. When used in combination with fluconazole or nystatin, compound 3 revealed an minimum inhibitory concentration (MIC) decrease by 4 fold for both drugs used. In-depth molecular studies with compound 3 on C. albicans showed that this compound inhibited yeast to hyphae (Y-H) conversion and this involved the cAMP pathway. Further, SEM images of C. albicans showed that compound 3 caused membrane damage and inhibited biofilm formation. Biochemical evidence for membrane damage was confirmed by increased propidium iodide (PI) uptake in flow cytometry. Further, in silico studies revealed that compound 3 docks with the active site of the key enzyme 14-α-demethylase and this might inhibit ergosterol synthesis. In support of this, ergosterol levels were found to be decreased by 32 fold in compound 3 treated samples as analyzed by high performance liquid chromatography (HPLC). Further, the antifungal activity of compound 3 was evaluated in an ex vivo dentinal tubule infection model, which mimics human tooth root canal infection. Confocal laser scanning microscopy studies showed 83% eradication of C. albicans and a 6 log reduction in colony forming unit (CFU) after 24h treatment in the infected tooth samples in this model.

CONCLUSION

Compound 3 was found to be very effective in eradicating C. albicans by inhibiting cAMP pathway and ergosterol biosynthesis.

GENERAL SIGNIFICANCE

The results of this study can pave the way for developing new antifungal agents with well deciphered mechanisms of action and can be a promising antifungal agent or medicament against root canal infection.

Dentinal Tubule Disinfection with Propolis & Two Extracts of Azadirachta indica Against Candida albicans Biofilm Formed on Tooth Substrate

Aim:

This study evaluates the disinfection of dentinal tubules using Propolis, Azadirachta indica (alcoholic and aqueous extracts), 2% chlorhexidine gel and calcium hydroxide against Candida albicans biofilm formed on tooth substrate.

Materials & Method:

One hundred and five human teeth were infected with Candida albicans for 2 days. Samples were divided into 7 groups. Group I- Propolis, Group II- Alcoholic extract of Azadirachta indica, Group III- Aqueous extract of Azadirachta indica, Group IV- 2% Chlorhexidine, Group V- Calcium hydroxide, Group VI- Ethanol and Group VII- Saline (negative control). At the end of 1,3 and 5 days, the antimicrobial efficacy of medicaments against Candida albicans was assessed at the depths of 200 µm and 400 µm.

Results:

The overall percentage inhibition of fungal growth (at 200 µm and 400 µm depth) was 99.2% with 2% chlorhexidine gel. There was no statistical difference between propolis, alcoholic extract of Azadirachta indica (neem) and 2% chlorhexidine.

Conclusion:

Propolis and alcoholic extract of Azadirachta indica performed equally well as that of 2% Chlorhexidine.

Aspergillus in endodontic infection near the maxillary sinus

Introduction

Diseases of the maxillary sinus have been associated with dental roots near the maxillary sinus that have undergone endodontic treatment.

Objective

To investigate the presence of filamentous fungi in patients with dental roots near the maxillary sinus who had apical periodontitis treated endodontically, and to alert practitioners that this could be a possible avenue of contamination of the sinus in patients who develop maxillary sinus infection.

Methods

Cross-sectional study in 60 palatal roots of the first maxillary molars near the maxillary sinus, that underwent endodontic treatment for apical periodontitis. After removal of the filling material, dentin shavings were collected and placed in test tubes containing Sabouraud dextrose agar and chloramphenicol. The phenotype was determined by macroscopic and microscopic examination of the colonies. For polymerase chain reaction, the primers ITS-5 and ITS-4 were used. The sequences obtained were compared with those deposited at GenBank using the Basic Local Alignment Search Tool program.

Results

Filamentous fungi were isolated from 6 of 60 canals (10%): Aspergillus niger (6.7%), Aspergillus versicolor (1.6%), and Aspergillus fumigatus (1.6%).

Conclusion

Root canals near the maxillary sinus with endodontic treatment and apical periodontitis may exhibit positive cultures for filamentous fungi. Interested professionals should be alert, because these microorganisms have pathogenic characteristics that can cause disease of odontogenic origin in the maxillary sinus.

Effects of the association of antifungal drugs on the antimicrobial action of endodontic sealers

This in vitro study aimed to determine the susceptibility of oral specimens and ATCC lineages of Candida albicans for five endodontic sealers, which were pure and associated with two antifungal drugs, and to analyze their effect on the physical properties. For this purpose, 30 lineages of C. albicans, collected from the oral cavity of patients assisted at the endodontics clinic of the Universidade Sagrado Coração, were analyzed. Yeasts susceptibility to the sealers was tested by diffusion on agar plates. Physical properties were evaluated according to the ADA specification no. 57. The pure versions of the Sealer 26, AH Plus, Endofill, Fillapex, and Sealapex demonstrated antifungal activity, with Endofill presenting the greatest inhibition zones. All cements, except for Endofill, had their antifungal actions enhanced by addition of ketoconazole and fluconazole (p < 0.05), and the AH Plus presented the best antifungal activity. The addition of antifungal drugs did not interfere with the setting time and flowability of the sealers. It was concluded that the addition of antifungals to endodontic sealers enhanced the antimicrobial action of most cements tested without altering their physical properties.

Comparison of the Antifungal Efficacy of 1.3% NaOCl/MTAD with Other Routine Irrigants: An Ex-Vivo Study

Objectives. To evaluate and compare the antifungal efficacy of 1.3% NaOCl/MTAD with 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine gluconate (CHX), and iodine potassium iodide (IKI). Materials and Methods. Fifty-two single rooted teeth were used which were divided into four groups with 10 teeth in each group: 2.5% NaOCl, 2% CHX, IKI, 1.3% NaOCl/MTAD, and physiologic saline. Two teeth served as negative controls and were placed in fresh brain-heart infusion broth (BHI) after autoclaving. The teeth were inoculated and incubated with Candida albicans after which the teeth were instrumented and irrigated with the test irrigants. The first microbial sampling was then performed and colony forming unit/mL (cfu/mL) was counted. The second microbial sampling was performed 1 week after instrumentation and irrigation. Results. The test irrigants were effective against C. albicans in both the first and second microbial samplings. When the irrigants were compared, there was no statistical difference in their activity in the 1st and 2nd microbial sampling. On comparison of the change in mean cfu/mL between the 1st and 2nd microbial samplings, the antifungal activity of the test irrigants was in the order 2.5% NaOCl > 2% CHX > 1.3% NaOCl/MTAD > IKI.

Periapical inflammation subsequent to coronal inoculation of dog teeth root filled with resilon/epiphany in 1 or 2 treatment sessions with chlorhexidine medication

INTRODUCTION

Therapeutic methods that inhibit microbial ingress into filled root canals are desirable. This in vivo study assessed the inhibition of periapical inflammation subsequent to coronal inoculation in canals medicated with 2% chlorhexidine gel and filled with Resilon/Epiphany (Pentron Clinical Technologies, Wallingford, CT).

METHODS

Six Beagle dogs each had 10 two-rooted premolars treated. In group 1 (n = 36 roots), 1 root/tooth had the canal conditioned with Primer Epiphany, filled with Epiphany sealer and Resilon core in 1 session, and coronally sealed with PhotacFil. In group 2 (n = 36 roots), the second root/tooth had the canal medicated with 2% chlorhexidine gel for 1 week and then filled and coronally sealed as in group 1. After 3 weeks, canals were exposed to the oral environment for 7 days, inoculated with isologous plaque, and coronally sealed. Negative controls treated as groups 1 and 2 remained sealed. Positive controls had canals unfilled and exposed. Seven months after inoculation, dogs were euthanized; jaw blocks processed for histologic examination; and periapical inflammation (PI) recorded as none, mild, or severe.

RESULTS

In groups 1 and 2, severe PI occurred in 5 of 65 roots (8%) and mild PI in 18 of 65 roots (28%) with a significantly higher (P = .031) PI incidence in group 2 than in group 1. Negative controls had only mild PI in 9 of 29 roots (31%). Roots medicated with 2% chlorhexidine gel had mild PI significantly more (P = .009) than roots filled in 1 session (more than 2-fold).

CONCLUSIONS

Intracanal medication with 2% chlorhexidine gel and root filling with Resilon/Epiphany did not effectively inhibit apical periodontitis subsequent to coronal inoculation.

Comparison of the antibacterial effect and smear layer removal using photon-initiated photoacoustic streaming aided irrigation versus a conventional irrigation in single-rooted canals: an in vitro study

OBJECTIVE

The Er:YAG laser with photon-induced photoacoustic streaming (PIPS) technique was reported to be effective in root canal disinfection. This study attempted to further investigate the antibacterial efficacy and smear layer removal ability of PIPS in comparison with conventional syringe irrigation in vitro.

METHODS

For antibacterial analysis, 48 single-rooted human teeth were prepared and inoculated with Enterococcus faecalis, and then divided into six groups of eight roots each. The colony-forming units (CFUs) per milliliter were determined after infection as the baseline. Then, the teeth were subjected to either PIPS plus 3% sodium hypochlorite (PIPS+NaOCl) or conventional syringe irrigation with 0.9% saline, 3% NaOCl, 17% ethylenediaminetetraacetic acid (EDTA), 0.2% chlorhexidine gluconate (CHX), or 3% NaOCl alternating with 17% EDTA. The reduction of CFUs in the individual group was determined. Additionally, scanning electron microscopy (SEM) examination of the canal walls for E. faecalis colonization was performed. For comparing the smear removal efficacy, another 48 single-rooted teeth, assigned to different groups as mentioned, were irrigated after mechanical instrumentation. The presence of a smear layer at different levels of the root canal was scored by SEM examination.

RESULTS

No significant differences were found in CFU reduction. No bacteria could be observed by SEM in the NaOCl, NaOCl+EDTA, and PIPS+NaOCl groups. The scores of smear layer of the NaOCl+EDTA and PIPS+NaOCl groups were significantly lower than those of the other groups in the coronal and middle third of the root canal. None of the methods can effectively remove smear layer in the apical third.

CONCLUSIONS

PIPS system supplied with NaOCl and conventional syringe irrigation with NaOCl+EDTA are comparable in their ability to remove E. faecalis and smear layer in single-rooted canals.

Antimicrobial efficacy of octenidine hydrochloride, MTAD and chlorhexidine gluconate mixed with calcium hydroxide

OBJECTIVE

The aim of this in vitro study was to investigate whether mixing with calcium hydroxide [Ca(OH)2] affects the antimicrobial action of Octenidine hydrochloride (Octenisept), MTAD and chlorhexidine against Enterococcus faecalis and Candida albicans.

MATERIALS AND METHODS

Freshly grown cultures of Enterococcus faecalis, Candida albicans and a mixture of both strains were incubated in agar plates containing brain-heart infusion broth (BHIB). Zones of inhibition were measured at 24 and 48 hours. Statistical analysis was performed using Mann-Whitney U test and Kruskal-Wallis one-way analysis of variance (ANOVA, both p=0.05).

RESULTS

Mixing with Ca(OH)2 significantly increased the antibacterial effect of Octenisept (p<0.05), but did not alter its antifungal activity. Only chlorhexidine showed more antibacterial and antifungal efficiency compared to its Ca(OH)2-mixed version (both p<0.05). Mixing with Ca(OH)2 decreased the antibacterial efficacy of MTAD, but increased its antifungal effect (both p<0.05).

CONCLUSION

These results demonstrate the differential effects of Ca(OH)2 addition on the antimicrobial action of the tested endodontic medicaments in vitro. Ca(OH)2 was as effective as its combination with all of the tested medicaments.

Evaluation of antimicrobial efficacy of calcium hydroxide paste, chlorhexidine gel, and a combination of both as intracanal medicament: An in vivo comparative study

Aim:

To compare the antimicrobial efficacy of calcium hydroxide (CH), 2% chlorhexidine gel (CHX) and a combination of both, on obligate anaerobes, facultative anaerobes and Candida spp .

Materials and Methods:

90 single rooted permanent teeth were included in the study. After complete disinfection and access opening, the first microbiological pre-treatment sample (S1) was collected. After completion of instrumentation, a post-instumentation sample (S2) was taken and the teeth were divided into three groups: Group I: CH, Group II: 2% CHX, Group III: 2% CHX with CH. After 1 week, a post-medication sample (S3) was collected.

Results:

All three medicaments were effective in the elimination of obligate anaerobes. CHX and combination showed higher antimicrobial effect against facultative anaerobes and Candida spp. in comparison with CH. But there was no statistical significant difference between Group II and Group III.

Conclusion:

CHX with or without CH was more effective than CH alone against all the tested micro-organisms.

Antimicrobial activity of calcium hydroxide in endodontics: a review

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.

Evaluation of the antibacterial effect of calcium hydroxide in combination with three different vehicles: An in vitro study

Introduction:

Antimicrobial activity of interappointment intracanal medications is an important consideration in endodontics. Considering the fact that calcium hydroxide (CH) cannot sterilize the root canal system, completing its antimicrobial spectrum seems necessary. The aim of this study was to compare the antibacterial activity of CH combined with three different vehicles in root canal system.

Materials and Methods:

In this in vitro experimental study, 61 freshly extracted human single rooted teeth were used. After chemo-mechanical preparation, the teeth were dressed with CH in combination with: G1: Distilled water (DW); G2: 5.25% sodium hypochlorite; G3: 0.2% chlorhexidine solution. All teeth were mounted in a 2-chamber apparatus. After sterilization, the coronal chamber was exposed to bacteria and the apical chamber was filled with broth for 90 days. Leakage was recorded when turbidity was observed in broth. Mean times of leakage and turbidity percentage were recorded for each group. Data were analyzed by One Way ANOVA test (α=0.005).

Results:

The highest mean time of contamination was for chorhexidine/CH combination (M=66.76 days), and the lowest was for DW/CH combination (M=40.29 days). Statistically significant difference was observed between G3 and G1 (P=0.042), but the difference between G2 and G3 (P=0.76) or G1 and G2 (P=0.18) were not significant. 88.23% of the samples of G1, 70.58% of G2, and 64.70% of G3 were contaminated after 3 months.

Conclusion:

As an intracanal medication, the chlorhexidine/CH combination had significantly more antibacterial activity than DW/CH combination.

The effect of temperature and contact time of sodium hypochlorite on human roots infected with Enterococcus faecalis and Candida albicans

The aim of this study was to evaluate the effectiveness of 2.5 % NaOCl at different temperature and time intervals on Enterococcus faecalis and Candida albicans-infected human roots. A total of 112 root cylinders prepared from extracted single-rooted humans were infected by E. faecalis (Group A, n = 56) or C. albicans (Group B, n = 56); 3 root cylinders served as negative controls. Both groups were further divided into 6 subgroups according to three contact times (30 s, 1 min, 5 min) with NaOCl at two different temperatures (25 or 37 °C). Microorganism growth was controlled at the 24th and 48th hours. Statistical analysis was performed using the Chi-square test. While NaOCl at 25 °C for 5 min was the most effective irrigation regimen to eliminate E. faecalis (p < 0.001), NaOCl at 37 °C for 5 min exhibited significantly superior antifungal properties (p < 0.05). At the same contact times, difference in the temperature of NaOCl did not affect the growth of either E. faecalis or C. albicans. As a result, the irrigation time of NaOCl was more effective than the temperature to eliminate E. faecalis, while pre-heating of NaOCl to 37 °C increased its effectiveness on C. albicans at 5 min contact time.

Response of mice connective tissue to intracanal dressings containing chlorhexidine

Substances containing chlorhexidine (CHX) have been studied as intracanal medicaments. The aim of the present study was to characterize the response of mouse subcutaneous connective tissue to CHX-containing medications by conventional optical microscopy. The tissue response was evaluated by implanting polyethylene tubes containing one of the substances evaluated: Calen paste + 0.5% CHX, Calen + 2% CHX, 2% CHX gel, and Calen paste (control). After experimental periods of 7, 21, and 63 days, the implants (n = 10) were removed along with the subcutaneous connective tissue. Tissue samples were subjected to histological processing, and sections were stained with hematoxylin and eosin. Qualitative and quantitative analyses of the number of inflammatory cells, blood vessels, and vascularized areas were performed. Results were analyzed by ANOVA and Tukey tests with the significance level set at 5%. We concluded that Calen + 0.5% CHX led to reparative tissue response in contrast with Calen + 2% CHX and 2% CHX gel, which induced persistent inflammatory response, pointing to the aggressive nature of this mixture. When Calen + 2% CHX and 2% CHX gel were compared, the latter induced more intense inflammatory response.

Endodontic 'solutions' part 1: a literature review on the use of endodontic lubricants, irrigants and medicaments

Endodontic lubricants, irrigants and medicaments help prepare and disinfect root canal systems (RCS) but primary and secondary cases involve different microbes and therefore it is unlikely that one protocol will be effective for both case types. Each individual 'solution' or sequence of'solutions' could play a significant role in each case type, but there are no detailed published guidelines in existence. To help inform clinical practice it was decided to undertake a literature review followed by a UK and Republic of Ireland wide audit on current endodontic'solution' usage within dental schools. The literature review was undertaken under the following headings: pre-op oral rinse; file lubricants; root canal irrigants and intracanal medicaments and provides an evidence base for protocol development for both primary and retreatment cases.The audit project and the protocols developed from the findings of both the literature review and audit will be presented in Part 2.

Comparative study of the antimicrobial effect of three irrigant solutions (chlorhexidine, sodium hypochlorite and chlorhexidinated MUMS)

AIM

To compare the antimicrobial effect of 2% chlorhexidine, 2.5% sodium hypochlorite and MUMS containing 2% chlorhexidine.

MATERIALS AND METHODS

All of the above irrigants were examined on Enterococcus faecalis, Streptococcus mutans, Candida albicans, Lactobacillus casei and E. coli. A total of 0.5 CC of each solution and 0.5 CC of McFarland solution bacterium were added to each examination tube. After 15, 30 and 45 minutes, colony count was performed for each tube. The difference in the number of bacteria indicated the effect taken by disinfectant material.

RESULTS

MUMS containing chlorhexidine showed the antimicrobial properties just like chlorhexidine's effect against E. coli, Streptococcus mutans, Candida albicans, Enterococcus faecalis and Lactobacillus casei in preventing these entire microorganisms to incubate. Sodium hypochlorite was not effective against Enterococcus faecalis and Candida albicans incubated in 15, 30 and 45 minutes and Enterococcus faecalis in 15 minutes.

CONCLUSION

MUMS has antimicrobial properties similar to chlorhexidine.

CLINICAL SIGNIFICANCE

As MUMS containing chlorhexidine can transfer chlorhexidine through its own surfactant around apical area and it can open the dentinal tubules by its own chelator for more penetration of chlorhexidine, it may be a choice for canal irrigation.

The effect of various concentrations of iodine potassium iodide on the antimicrobial properties of mineral trioxide aggregate--a pilot study

BACKGROUND

Mineral trioxide aggregate (MTA) is a multi-purpose dental material with various uses in dentistry. Iodine potassium iodide (IKI) is the most commonly used iodine compound in endodontics. We aimed to assess the antimicrobial activity of tooth-colored ProRoot MTA combined with IKI.

MATERIALS AND METHODS

The antimicrobial activity of IKI was assessed at three concentrations (1%, 2%, and 4%) as the mixing agents combined with MTA against Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. For each microorganism, three plates were inoculated with 100 μl of a microbial suspension (McFarland 0.5). Four wells were prepared in each plate. MTA (70 mg) was mixed with any of the three concentrations of IKI (25 μl) or sterile distilled water (25 μl) and placed in each well. The plates were incubated for 24 h at 37°C. Zones of inhibition (ZOI) were measured in millimeters by a blinded observer. Data were analyzed using analysis of variance and the Dunnett t-test.

RESULTS

All MTA mixtures with water or IKI solutions showed inhibitory zones. The mean ZOI of each MTA/IKI mixture was not significantly different from MTA/water mixture (P > 0.05). MTA/1% IKI had smaller ZOI than MTA/water against E. coli, E. faecalis, and C. albicans. MTA/2% IKI showed larger ZOI only against P. aeruginosa. MTA/4% IKI showed larger ZOI against P. aeruginosa and E. coli (P < 0.05).

CONCLUSIONS

Substitution of IKI solutions (1%, 2%, and 4%) for water did not significantly increase the antimicrobial activity of MTA.

An in vitro evaluation of antifungal activity of bioaggregate

OBJECTIVE

The aim of this study was to evaluate, in vitro, the antifungal effect of bioaggregate (BA) against Candida albicans by using the direct contact method.

STUDY DESIGN

BA was tested freshly mixed and after 24-hour set on C. albicans. The tested BA was incubated with C. albicans in plastic tissue clusters for 1 hour, 24 hours, and 3 and 5 days. Aliquots of 0.1 mL were taken from each well at the end of the incubation periods and transfered to tubes containing 5 mL fresh Sabouraud broth. All tubes were vortexed and then incubated at 37°C and observed for the subsequent 5 days. Growth of the fungi was observed daily by the presence of turbidity in the tubes. The results were statistically analyzed by using Kaplan-Meier test.

RESULTS

The freshly mixed and set BA had no antifungal effect at 1 and 24 hours of contact. Both mixes demonstrated complete fungicidal activity after 24 hours' contact. Statistical analysis showed a highly significant difference between the negative and positive control groups (P < .001) and a significant difference between the freshly mixed and 24-hour set BA groups (P < .001) at 24 hours.

CONCLUSIONS

BA (freshly mixed and 24-hour set) was effective against C. albicans after 24 hours.

In vitro susceptibility of oral Candida albicans strains to different pH levels and calcium hydroxide saturated aqueous solution

Candida albicans is present in the oral cavity and in the whole digestive tract of humans and other animals, being frequently related to endodontic treatment failure. The present study determined the incidence of C. albicans in the oral cavity and the susceptibility of isolates to different pH values and saturated calcium hydroxide aqueous solution at pH 12.5. Sixty-five patients attending the Endodontic Clinic at the Sagrado Coração University participated in the study. The collected samples were cultivated in selective media for C. albicans and the isolates were tested in terms of resistance to both alkaline pH and saturated aqueous solution of calcium hydroxide. In relation to time variables, yeast viability was assessed by the Sabouraud's agar culture and fluorescein diacetate and ethidium bromide fluorescent staining method. Results from the different pHs and experimental times, including those from different techniques measuring fungal viability, were compared using the chi-square and Fisher's exact tests (α=0.05). The yeasts became completely inviable after 48 h of contact with the calcium hydroxide solution. On the other hand, when exposed to the alkaline culture broth, the yeasts were found to be viable at pHs 9.5 and 10.5 for up to 7 days. In conclusion, C. albicans can only be completely inhibited by direct contact with saturated calcium hydroxide aqueous solution after 48 h of exposure.

Newer root canal irrigants in horizon: a review

Sodium hypochloride is the most commonly used endodontic irrigant, despite limitations. None of the presently available root canal irrigants satisfy the requirements of ideal root canal irrigant. Newer root canal irrigants are studied for potential replacement of sodium hypochloride. This article reviews the potential irrigants with their advantages and limitations with their future in endodontic irrigation.