Occurrence of Candida albicans in infections of endodontic origin

Fungi and bacteria occupy distinct spatial niches within carious dentin

The role of bacteria in the etiology of dental caries is long established, while the role of fungi has only recently gained more attention. The microbial invasion of dentin in advanced caries especially merits additional research. We evaluated the fungal and bacterial community composition and spatial distribution within carious dentin. Amplicon 16S rRNA gene sequencing together with quantitative PCR was used to profile bacterial and fungal species in caries-free children (n = 43) and 4 stages of caries progression from children with severe early childhood caries (n = 32). Additionally, healthy (n = 10) and carious (n = 10) primary teeth were decalcified, sectioned, and stained with Grocott's methenamine silver, periodic acid Schiff (PAS) and calcofluor white (CW) for fungi. Immunolocalization was also performed using antibodies against fungal β-D-glucan, gram-positive bacterial lipoteichoic acid, gram-negative endotoxin, Streptococcus mutans, and Candida albicans. We also performed field emission scanning electron microscopy (FESEM) to visualize fungi and bacteria within carious dentinal tubules. Bacterial communities observed included a high abundance of S. mutans and the Veillonella parvula group, as expected. There was a higher ratio of fungi to bacteria in dentin-involved lesions compared to less severe lesions with frequent preponderance of C. albicans, C. dubliniensis, and in one case C. tropicalis. Grocott's silver, PAS, CW and immunohistochemistry (IHC) demonstrated the presence of fungi within carious dentinal tubules. Multiplex IHC revealed that fungi, gram-negative, and gram-positive bacteria primarily occupied separate dentinal tubules, with rare instances of colocalization. Similar findings were observed with multiplex immunofluorescence using anti-S. mutans and anti-C. albicans antibodies. Electron microscopy showed monomorphic bacterial and fungal biofilms within distinct dentin tubules. We demonstrate a previously unrecognized phenomenon in which fungi and bacteria occupy distinct spatial niches within carious dentin and seldom co-colonize. The potential significance of this phenomenon in caries progression warrants further exploration.

Prevalence of Enterococcus faecalis and Candida albicans in endodontic retreatment Cases: A comprehensive study

Introduction

Endodontic treatment failures often stem from the presence of microbial pathogens, particularly Enterococcus faecalis and Candida albicans. This study systematically assesses the prevalence of E. faecalis and C. albicans in endodontic retreatment cases, aiming to explore their impact on treatment outcomes.

Methods

Employing a systematic sampling approach, 30 patients with a history of previous endodontic treatment were selected. Rigorous clinical and radiographic assessments were conducted, following standardized protocols for root canal sample collection. Microbiological analysis, utilizing selective culture media, was employed to identify and quantify E. faecalis and C. albicans. Statistical analyses, including chi-square and logistic regression tests, were performed.

Results

The study involved 30 patients undergoing endodontic retreatment, with comprehensive clinical and radiographic evaluations for cases with and without periradicular lesions. Microbiological analysis unveiled a significant prevalence of E. faecalis and C. albicans, establishing a robust association between these pathogens and retreatment failure. These findings underscore the critical need for targeted antimicrobial interventions to enhance the overall success rates of endodontic retreatment procedures.

Conclusion

This study highlights the substantial prevalence of E. faecalis and C. albicans in endodontic retreatment cases, emphasizing the importance of identifying and effectively managing these pathogens for successful treatment outcomes. The notable association between these microbial agents and retreatment failure underscores the imperative for tailored antimicrobial strategies to enhance the efficacy of endodontic retreatment procedures.

Evaluation of Antimicrobial Effectiveness of Root Canal Sealers Modified with Various Herbal Extracts against Candida Albicans and E Faecalis

Objectives

The aim of the study was to assess the effectiveness of ZOE-based, calcium hydroxide, and epoxy resin-based sealers on modification with three herbal extracts.

Materials and Methods

Methanolic extracts of selected herbs were combined with ZOE-based, calcium hydroxide, and epoxy resin-based sealers. Cultures were prepared from E. faecalis and C. albicans and agar plates prepared. Prepared mixtures were inoculated in punched holes, and inhibitory zones were measured.

Results

No statistical significance was obtained on comparing mean scores of test groups.

Conclusion

None of the combinations used was found to be significantly better than others.

The Effectiveness of Silver Nanoparticles Mixed with Calcium Hydroxide against Candida albicans: An Ex Vivo Analysis

INTRODUCTION

The purpose of this study was to assess the antifungal activity of silver nanoparticles (AgNPs) in combination with calcium hydroxide (Ca(OH)2) against Candida albicans (C. albicans).

METHODS

AgNPs was mixed with pure Ca(OH)2 powder in an aqueous base. A standard suspension (1 × 108 bacterial cells/mL) of C. albicans was prepared in a 96-well plate and incubated on shaker at 37 °C in 100% humidity to allow fungal biofilm formation in infected dentin slices (n = 98). The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of AgNPs alone or with Ca(OH)2 were determined. The samples were separately placed in 24-well tissue culture plates and divided into three experimental groups (0.03, 0.04, and 0.06) and three control groups; negative (saline) and positive chlorhexidine gel and Ca(OH)2. Quantitative measurements of fungal activity by XTT colorimetric assay and qualitative measurements using confocal laser microscopy and scanning electron microscopy were performed.

RESULTS

The cell viability of C. albicans in the experimental groups was significantly reduced compared to the negative control group. The combination of (AgNPs (0.04%) and Ca(OH)2) was the most potent against C. albicans.

CONCLUSIONS

The findings demonstrated that combining silver nanoparticles with Ca(OH)2 was more effective against C. albicans biofilm compared to Ca(OH)2 alone, suggesting a combing effect.

Cross-kingdom interaction between Candida albicans and oral bacteria

Candida albicans is a symbiotic fungus that commonly colonizes on oral mucosal surfaces and mainly affects immuno-compromised individuals. Polymicrobial interactions between C. albicans and oral microbes influence the cellular and biochemical composition of the biofilm, contributing to change clinically relevant outcomes of biofilm-related oral diseases, such as pathogenesis, virulence, and drug-resistance. Notably, the symbiotic relationships between C. albicans and oral bacteria have been well-documented in dental caries, oral mucositis, endodontic and periodontal diseases, implant-related infections, and oral cancer. C. albicans interacts with co-existing oral bacteria through physical attachment, extracellular signals, and metabolic cross-feeding. This review discusses the bacterial-fungal interactions between C. albicans and different oral bacteria, with a particular focus on the underlying mechanism and its relevance to the development and clinical management of oral diseases.

Y, Efendi D, Razak FA. ACE2 expression in saliva of patients with COVID-19 and its association with Candida albicans and Aggregatibacter actinomycetemcomitans

Background: A relationship between oral microbiota and susceptibility to SARS-CoV-2 infection has been extensively studied. However, the relationship between oral commensal flora and expression of angiotensin-converting enzyme 2 ( ACE2) remains to be established. In this observational study, we collected saliva from patients with COVID-19 and evaluated the relationship between ACE2 expression and Candida albicans as well as with selected gram-negative bacteria ( Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Veillonella parvula). We investigated how this may be directly or indirectly involved in oral dysbiosis in patients with COVID-19.

Methods: We included 23 hospitalized patients admitted to Universitas Indonesia Hospital with PCR-confirmed COVID-19, with six healthy participants serving as controls. Saliva and tongue surface swabs were collected from patients with diabetes (DG) and without diabetes (NDG) and subject controls. Using quantitative PCR (qPCR) we assessed the mRNA expression of ACE2, the abundance of C. albicans, and the transcription levels of its biofilm-associated genes, agglutinin-like protein 3 ( ALS3), hyphal wall protein 1 ( HWP1), and yeast-form wall protein 1 ( YWP1). We also counted the relative proportion of the three selected gram-negative oral bacteria in saliva. All analyses were performed to determine the relationship between ACE2 expression and C. albicans and gram-negative bacteria.

Results:ACE2 mRNA expression was significantly higher in tongue swab samples than in saliva. However, no significant difference was observed between the patient groups. Conversely, DG patients had a significantly higher abundance of C. albicans in saliva compared to NDG patients and control group patients. The correlation and sensitivity/specificity relationship between ACE2 expression and C. albicans or the selected oral bacteria were also observed.

Conclusions: The data show that ACE2 expression can be detected in saliva of patients with COVID-19 and its association with C. albicans and gram-negative oral bacteria might contribute toward developing an oral dysbiosis based predictor for prognosis of COVID-19 severity.

Hydroalcoholic Leaf Extract of Punica granatum, alone and in Combination with Calcium Hydroxide, Is Effective against Mono- and Polymicrobial Biofilms of Enterococcus faecalis and Candida albicans

Failures in endodontic treatments are mostly associated with the difficulty in eradicating microbes of the root canal system, highlighting the need to develop novel effective antimicrobials. Punica granatum (pomegranate) leaf hydroalcoholic extract may be a potential alternative in canal dressing, owing to its antimicrobial properties. The objective of this study was to evaluate the antimicrobial activity of hydroalcoholic leaf extract of Punica granatum (HEPg) alone or in combination with calcium hydroxide (Ca(OH)₂) against Enterococcus faecalis and Candida albicans in isolation and in mono- and polymicrobial biofilms. Microdilution tests in broth and assays for inhibition of biofilm formation were carried out to evaluate the antimicrobial properties of HEPg and HEPg + Ca(OH)₂ against Enterococcus faecalis and Candida albicans. The cytotoxicity of HEPg in HaCaT cells was evaluated by MTT assay. HEPg and HEPg + Ca(OH)₂ exerted significant antimicrobial activity against planktonic cells and mono- and polymicrobial biofilms. The combination of Punica granatum extract with Ca(OH)₂ appears to be a promising alternative in endodontic treatments, which could be tested in vivo to confirm the efficacy of this mixture in disinfecting root canal systems.

Evaluation of Antibacterial and Antifungal Effects of Calcium Hydroxide Mixed with Two Different Essential Oils

BACKGROUND

Calcium hydroxide is a routinely used material for root canal disinfection during root canal treatment. Natural products have great potential in terms of their antibacterial effects. This study aimed to establish an effective alternative intracanal medicament using Origanum dubium (O. dubium) and Mentha spicata (M. spicata) essential oils.

MATERIALS AND METHODS

O. dubium and M. spicata, collected from Lefke, Cyprus, were separately subjected to hydrodistillation. The obtained essential oil compositions were analysed simultaneously by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). The compositions were then divided into groups and mixed with calcium hydroxide at a 1:1 concentration; after that, the pastes were tested on Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans), which are the most common resistant pathogenic microorganisms in the root canal. The antibacterial activity of the pastes was measured using a disk diffusion assay.

RESULTS

The GC and GC-MS analyses revealed that O. dubium and M. spicata had major compositions of carvacrol (75.8%) and carvone (71.3%), respectively. Antimicrobial activity was found to be significantly higher when study groups with O. dubium essential oil were applied to both E. faecalis and C. albicans. The results also show that M. spicata, together with calcium hydroxide, demonstrated a significant antifungal effect on C. albicans when incubated for 72 h.

CONCLUSIONS

M. spicata was found to be an effective antimicrobial agent on C. albicans, whereas O. dubium was found to be very effective on both E. faecalis and C. albicans. These data demonstrate that these natural essential oils may be promising candidates for alternative intracanal medicament in future routine clinical applications.

Present status and future directions - microbiology of endodontic infections

Apical periodontitis has a microbial aetiology and is one of the most common inflammatory diseases that affect humans. Fungi, archaea and viruses have been found in association with apical periodontitis, but bacteria are by far the most prevalent and dominant microorganisms in endodontic infections. Bacterial infection of the root canal system only occurs when the pulp is necrotic or was removed for previous treatment. In some specific cases, including acute and chronic abscesses, the bacterial infection may reach the periradicular tissues. Intracanal bacteria are usually observed as sessile multispecies communities (biofilms) attached to the dentinal root canal walls. Infection in the main root canal lumen can spread to other areas of the root canal system. Although more than 500 bacterial species have been detected in endodontic infections, a selected group of 20 to 30 species are most frequently detected and may be considered as the core microbiome. There is a high interindividual variability in the endodontic microbiome in terms of species composition and relative abundance. Obligate anaerobic species are more abundant in the intraradicular bacterial communities of teeth with primary apical periodontitis, while both anaerobes and facultatives dominate the communities in post-treatment apical periodontitis. Bacterial interactions play an essential role in determining the overall virulence of the community, which has been regarded as the unit of pathogenicity of apical periodontitis. This article reviews the microbiologic aspects of endodontic infections and provides perspectives for future research and directions in the field.

Comparing the Antifungal Effect of Sodium Hypochlorite Gel versus Different Types of Root Canal Medicaments at Different Time Intervals Using the Agar Diffusion Test: An In Vitro Study

Aims

The purpose of this study was to compare the antifungal activity of sodium hypochlorite gel to those of four intracanal medicaments at various time intervals.

Materials and Methods

The agar well diffusion technique was utilized to test the antifungal activity of the following medicaments against Candida albinans (C. albicans): sodium hypochlorite gel, chlorhexidine gel, calcium hydroxide paste, Ledermix, and Diapex Plus. The inhibition zone related to each medicine was measured in millimeter after 24, 48, and 72 hours of incubation at 37°C. The data were analyzed using one-way ANOVA and Games–Howell tests, at a significance level of P < 0.05.

Results

Except for Ledermix and Diapex Plus, which had no antifungal action, all of the medicaments showed varied inhibitory zones for C. albicans. At all periods, the NaOCl gel had the most significant inhibition zones, followed by the CHX gel and calcium hydroxide. At all time intervals, the NaOCl gel demonstrated comparable antifungal efficacy. When compared to a 24-hour time interval, the CHX gel showed an increased antifungal activity at the 48-hour and 72-hour intervals. Calcium hydroxide, on the other hand, showed a decrease in its antifungal activity at the 72-hour interval.

Conclusion

The antifungal activity of sodium hypochlorite gel was the highest among the investigated medicaments. Chlorhexidine gel's antifungal activity improved over time, whereas calcium hydroxide's antifungal activity declined. Diapex Plus and Ledermix did not have any antifungal properties.

Prevalence of Fungi in Primary Endodontic Infections of a Greek-living Population Through Real-time Polymerase Chain Reaction and Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry

INTRODUCTION

Fungi are considered to be opportunistic pathogens that may play a significant role in the pathogenesis of endodontic infections. The main purpose of this study was to assess the prevalence of 2 selected genera of fungi, Candida albicans and Aspergillus spp., using real-time polymerase chain reaction (RT-PCR) and to compare the findings with the respective ones obtained by a culture-dependent approach, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS). A secondary aim was to assess the presence of other bacteria growing under aerobic conditions.

METHODS

Microbial samples were obtained from the root canals of 60 teeth associated with pulp necrosis and apical periodontitis. DNA was extracted, and RT-PCR was applied for the detection of C. albicans and Aspergillus spp. pathogenic subtypes. In addition, MALDI-ToF MS was performed to identify microorganisms grown under aerobic conditions.

RESULTS

Based on RT-PCR, Aspergillus was detected in 8 cases, whereas C. albicans was detected in 4 cases. Using MALDI-ToF MS, no trace of Aspergillus was detected, whereas C. albicans was identified in 2 cases. Significant differences were revealed in the detection potential for Aspergillus spp. between MALDI-ToF MS and RT-PCR (P = .01); conversely, this was not the case for C. albicans (P = .50). After MALDI-ToF MS, 35 samples showed evidence of bacterial growth. The vast majority was colonized by Achromobacter xylosoxidans followed by Lactobacillus spp., Methylobacterium spp., and Enterococcus faecalis.

CONCLUSIONS

The findings confirm the presence of fungi in primarily infected canals with apical periodontitis as well as some rarely inspected aerobic bacterial species. A. xylosoxidans was prevalent; however, the clinical relevance of its presence needs to be investigated further.

Fungal species in endodontic infections: A systematic review and meta-analysis

Fungal infections are common on oral mucosae, but their role in other oral sites is ill defined. Over the last few decades, numerous studies have reported the presence of fungi, particularly Candida species in endodontic infections, albeit in relatively small numbers in comparison to its predominant anaerobic bacteriome. Here, we review the fungal biome of primary and secondary endodontic infections, with particular reference to the prevalence and behavior of Candida species. Meta-analysis of the available data from a total of 39 studies fitting the inclusion criteria, indicate the overall weighted mean prevalence (WMP) of fungal species in endodontic infections to be 9.11% (from a cumulative total of 2003 samples), with 9.0% in primary (n = 1341), and 9.3% in secondary infections (n = 662). Nevertheless, WMP for fungi in primary and secondary infections which were 6.3% and 7.5% for culture-based studies, increased to 12.5% and 16.0% in molecular studies, respectively. The most prevalent fungal species was Candida spp. The high heterogeneity in the reported fungal prevalence suggests the need for standardized sampling, and speciation methods. The advent of the new molecular biological analytical platforms, such as the next generation sequencing (NGS), and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF), that enables identification and quantitation of a broad spectrum of hitherto unknown organisms in endodontic infections should radically alter our understanding of the endodontic mycobiome in the future. Candida spp. appear to be co-pathogens with bacteria in approximately one in ten patients with endodontic infections. Hence, clinicians should comprehend the importance and the role of fungi in endodontic infections and be cognizant of the need to eradicate both bacteria and fungi for successful therapy.

Synergistic Effect of Plant Extracts on Endodontic Pathogens Isolated from Teeth with Root Canal Treatment Failure: An In Vitro Study

BACKGROUND AND OBJECTIVES

This study aimed to evaluate the synergistic antimicrobial activity of extracts obtained from Salvadora persica (Miswak), Commiphora molmol (myrrh) and Azadirachta indica (neem) in combination with commercially available antimicrobial agents: penicillin, tetracycline, ofloxacin and fluconazole on endodontic pathogens such as Enterococcus faecalis, Streptococcus mitis,Actinomyces naeslundii and Candida albicans.

MATERIALS AND METHODS

Microbiological samples from the root canals of the teeth undergoing retreatment were taken using sterile paper points kept at full length in the canal for 30 s. The disc diffusion method was used to check the susceptibility of microbes to the plant extracts and antimicrobials by measuring the diameter of the inhibition zones. Against the microbes, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of the plant extracts were assessed. The fractional inhibitory concentration index (FICI) was used to estimate the synergistic effect of plant extracts combined with antimicrobials against the resistant endodontic microbes.

RESULTS

The findings clearly indicate the effectiveness of all the three plant extracts, Commiphora molmol, Azadirachta indica, Salvadora persica, against all the experimental pathogenic microorganisms except for the ineffectiveness of Azadirachta indica, Salvadora persica against Candidaalbicans. Maximum antimicrobial activity was displayed by Azadirachta indica against Enterococcusfaecalis (MIC = 0.09 ± 1.2 mg/mL, MBC = 0.78 ± 1.25 mg/mL) and the minimum antimicrobial activity was displayed by Commiphora molmol against Actinomyces naeslundii (MIC = 12.5 ± 3.25 mg/mL, MBC = 100 ± 3.75 mg/mL). The best synergy was displayed by Commiphora molmol with fluconazole against Candidaalbicans (FICI = 0.45).

CONCLUSIONS

The current study delineates the variable antimicrobial activity of plant extracts against the experimental endodontic pathogenic microorganisms. Plant extracts in conjunction with various antimicrobials can be valuable aids in combating relatively resistant endodontic microorganisms that have been the cause of worry in recent years, leading to failure even in treatment procedures following all required protocols.

Prevalence, virulence and antifungal activity of C. albicans isolated from infected root canals

Background

There is limited data on the prevalence of Candida species in infected root canal systems of human teeth. We attempted to investigate the prevalence, genotype, virulence and the antifungal susceptibility of Candida albicans isolated from infected root canals of patients with primary and post-treatment infections in a UAE population.

Methods

Microbiological samples from 71 subjects with infected root canals were aseptically collected, and cultured on Sabouraud dextrose agar, and C. albicans was identified using multiplex polymerase chain reaction, and the isolates were further subtyped using ABC genotyping system. Their relative virulence was compared using further four archival samples of endodontic origin from another geographical region, and four more salivary isolates, as controls. The virulence attributes compared were biofilm formation, and production of phospholipase and haemolysin, and the susceptibility to nystatin, amphotericin B, ketoconazole, and fluoconazole was also tested.

Results

4 out of 71 samples (5.6%) yielded Candida species. On analysis of variance among the groups, the intracanal isolates, mainly Genotype A, possessed a high degree of phospholipase and haemolysin activity (p < 0.05). The UAE and Finland isolates were stronger biofilm formers and had superior phospholipase production capacity compared with the salivary isolates. All isolates were sensitive to the antifungal chemicals used. The salivary isolates were more sensitive to fluoconazole compared to other groups (p < 0.05).

Conclusion

The prevalence of C. albicans in infected root canals of patients attending a dental hospital in UAE is low. The strains isolated were good biofilm formers, possessed strong phospholipase and haemolysin activity and were mostly of the genotype A. The fact that the root canal isolates possessed significant hydrolase activity, imply that they are equipped with virulence attributes necessary for survival within a harsh intracanal ecosystem.

Microbial interactions and immunity response in oral Candida species

Oral candidiasis are among the most common noncommunicable diseases, related with serious local and systemic illnesses. Although these infections can occur in all kinds of patients, they are more recurrent in immunosuppressed ones such as patients with HIV, hepatitis, cancer or under long antimicrobial treatments. Candida albicans continues to be the most frequently identified Candida spp. in these disorders, but other non-C. albicans Candida are rising. Understanding the immune responses involved in oral Candida spp. infections is a key feature to a successful treatment and to the design of novel therapies. In this review, we performed a literature search in PubMed and WoS, in order to examine and analyze common oral Candida spp.-bacteria/Candida-Candida interactions and the host immunity response in oral candidiasis.

Identification of microorganisms in irreversible pulpitis and primary endodontic infections with respect to clinical and radiographic findings

OBJECTIVES

The aim of this study was to evaluate the composition of microbiota of irreversible pulpitis and primary endodontic infections with respect to clinical and radiographic findings by performing cultures and 16s rDNA sequencing in Iranian patients.

MATERIAL AND METHODS

In this prospective cross-sectional study, samples were collected from 41 root canals for 4 main groups of patients. Bacterial identification was performed by the polymerase chain reaction (PCR) and 16s rDNA sequencing of aerobic and anaerobic cultivable colonies taken from patients' culture plates. Additionally, the presence of 13 bacterial species and 3 nonbacterial species was also explored using PCR and species-specific primers.

RESULTS

Sixteen microbial species, 1 fungus (Candida albicans), and 1 virus (Herpes simplex virus) were discovered and isolated. Species with the highest prevalence were Dialister invisus (68.3%), Porphyromonas gingivalis (58.8%), Streptococcus salivarius (58.5%), and Treponema denticola (56.1%). Lysinibacillus fusiformis (19.1%) was detected in the root canals for the first time. Candida albicans was seen in 11 cases (26.8%). Herpes simplex virus (HSV) was seen in 4 patients (9.8%).

CONCLUSIONS

Our results suggest that Gram-negative anaerobic oral bacteria are the majority of the microbes in primary endodontic infections. Various combinations of bacterial species were related to different clinical and radiographic conditions. Lysinibacillus fusiformis was detected for the first time in primary endodontic infections.

CLINICAL RELEVANCE

The results of this investigation might help clinicians choose to identify suspected endodontic pathogens in the etiology of each form of pulpal and periradicular diseases to determine the best therapeutic measures.

Comparative Evaluation of Antifungal Efficacy of Five Root Canal Sealers against Clinical Isolates of Candida albicans: A Microbiological Study

Aim and objective

The aim of this study was to evaluate and compare the antifungal efficacy of MTA Fillapex, Metapex, zinc oxide eugenol cement, Endomethasone, and Endoflas against Candida albicans.

Materials and methods

Root canal exudates of 30 patients were tested against MTA Fillapex (Angelus), Metapex (BioMed), zinc oxide eugenol (Deepak Enterprise), Endomethasone (Septodont), Endoflas FS (Sanlor Laboratories), MTA (Angelus) (positive control), and glycerine (negative control). Children with failed endodontic cases were included in the study. Tube dilution and agar diffusion methods were used to check the antifungal efficacy of the root canal sealers. In tube dilution method, 24-well culture plates containing freshly mixed material along with Candida albicans were used. Wells containing MTA (Angelus) along with Sabouraud dextrose agar and Candida albicans served as positive control while glycerine along with Sabouraud dextrose agar and Candida albicans served as negative control. All plates were incubated at 37°C for 24 hours. Growth of the fungi was monitored after 24 hours by the presence of the turbidity. The samples were recultured to test the experimental material using agar well diffusion method, and the Petri plates were incubated for 24 hours and 72 hours. Zone of inhibition was measured after respective time period. Paired t test was used for the data analysis.

Results

It was seen in tube dilution method Endomethasone showed least turbidity while maximum was shown by Metapex; similar results were seen in case of agar well diffusion method in which largest zone of inhibition was shown by Endomethasone while smallest was by Metapex.

Conclusion

It was concluded that Endomethasone showed maximum efficacy against Candida albicans as compared to Metapex.

How to cite this article

Singh S, Srivastava B, Gupta K, et al. Comparative Evaluation of Antifungal Efficacy of Five Root Canal Sealers against Clinical Isolates of Candida albicans: A Microbiological Study. Int J Clin Pediatr Dent 2020;13(2):119–123.

Prevalence of Candida albicans in primary endodontic infections associated with a higher frequency of apical periodontitis in type two diabetes mellitus patients

To identify the prevalence of C. albicans in primary endodontic infections of type two diabetes mellitus (T2DM) patients and compare their clinical and radiographical characteristics with a non-diabetic control group, establishing the possible relationship between primary endodontic infection, T2DM, and C. albicans, since diabetes mellitus (DM), influences the development, course, and response to the treatment of apical periodontitis, but the presence of Candida albicans (C. albicans) has not been considered before. A total of 120 patients were selected and divided into two groups: 60 T2DM diagnosed patients and 60 non-diabetic controls. A clinical examination and radiographic analysis were performed to establish a periapical index score (PAI). Root canal samples were taken. Deoxyribonucleic acid (DNA) was extracted, and specific primers were used to identify C. albicans by polymerase chain reaction (PCR). A twofold increase in the prevalence of C. albicans in T2DM patients was observed in contrast to control patients (p = 0.0251). Sixty-five percent of T2DM patients with positive C. albicans scored a ≥ 3 PAI, while only 27% of the patients without C. albicans had a ≥ 3 PAI score (p = 0.0065). Long-term DM patients presented C. albicans more frequently (p < 0.0001). In this study, long-term T2DM patients carried C. albicans in their root canals more frequently when having a primary endodontic infection. Furthermore, this C. albicans presence seems to be related to a higher frequency of apical periodontitis.

Prevalence of Candida Species in Endodontic Infections: Systematic Review and Meta-analysis

INTRODUCTION

Candida in endodontic infections has been investigated in a large number of studies, but its role as an endodontic pathogen is still debatable. The aim of this study was to systematically review the literature on the prevalence of Candida species in root canal infections.

METHODS

Extensive literature research was performed in the most important electronic biomedical databases, and additional studies have been identified from references from relevant articles. Studies were critically appraised using a modified version of the Joanna Briggs Institute Critical Appraisal Checklist.

RESULTS

From 2225 unique records, 2118 were excluded on the basis of title and abstract. Of the remaining 107 studies, 50 were excluded after full-text review, and 57 were included for qualitative and quantitative analysis. The overall prevalence of Candida spp. in root canal infections was 8.20% (95% confidence interval, 5.56%-11.21%). Candida albicans was the most frequently isolated species. Significant heterogeneity among studies was observed (P < .001, I² = 86.07%). Subgroup analyses revealed a higher prevalence of Candida spp. from African samples. All studies considered, a high or unclear risk of bias was prevalent regarding 6 out of the 8 items considered in the critical appraisal.

CONCLUSIONS

Candida spp. occurred in a small proportion of root canal infections. Further and better designed research is needed to investigate the real contribution of Candida spp. to the microbial ecology in infected root canals.

Mandibular Osteomyelitis Associated with Candida Albicans in Marijuana and Heroin Abusers

Osteomyelitis of the mandible is most commonly caused by bacterial infections and is rarely linked to fungal infections. In 2003, Friedman et al. studied the relationship of multiple drugs including marijuana, opioids, nicotine, and alcohol and its effect on the immune system. It is important to consider potential risks and complications of patients who are immunocompromised and present a history of substance abuse. These complications include infections and osteomyelitis which can be associated with multiple microorganisms; some of the most common microorganisms isolated in mandibular osteomyelitis include Streptococcus, Eikenella, and Candida. Candida albicans is commonly found in the skin and mucosa of healthy individuals; however, it has been proven to cause disease in individuals who are immunocompromised. Two cases of mandibular osteomyelitis after routine dental extractions and a history of drug abuse, including heroin and marijuana, are presented in this case series. These specific infections were resistant to multiple antibiotic therapy and grew C. albicans species in cultures collected. These cases were treated with irrigation and debridement or mandibular resection in combination with antimicrobial treatment and fluconazole with complete resolution. Although osteomyelitis is most commonly caused by bacterial infections, special attention must be given to patients with medical histories of immunosuppression and intravenous drug use. Patients who do not respond to broad-spectrum antibiotics might benefit from bacterial and fungal cultures and sensitivity. Antifungal treatment with an antifungal agent, such as oral fluconazole, is indicated if fungal organisms are yielded in the culture.

Presence of archaea and selected bacteria in infected root canal systems

Infections of the root canal have polymicrobial etiology. The main group of microflora in the infected pulp is bacteria. There is limited data that archaea may be present in infected pulp tissue. The aim of this study was to check the prevalence of archaea in necrotic root canal samples obtained from patients with primary or post-treatment infection. The prevalence of selected bacteria species (Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Synergistes sp.) in necrotic samples was evaluated as well. Sixty-four samples from root canal were collected for DNA and RNA extraction. A PCR assay based on the 16S rRNA gene was used to determine the presence of archaea and selected bacteria. Of the 64 samples, 6 were analyzed by semiquantitative reverse transcription PCR to estimate expression profiles of 16S rRNA, and another 9 were selected for direct sequencing. Archaea were detected in 48.4% samples. Statistical analysis indicated a negative association in coexistence between archaea and Treponema denticola (P < 0.05; Pearson’s χ2 test). The main representative of the Archaea domain found in infected pulp tissue was Methanobrevibacter oralis. Archaea 16S rRNA gene expression was significantly lower than Synergistes sp., Porphyromonas gingivalis, and Tannerella forsythia (P < 0.05; Student’s t test). Thus, it can be hypothesized that archaea may participate in the endodontic microbial community.

Root Canal Microflora

Modern day endodontics is undergoing a massive change with the introduction of new molecular based techniques for microbial identification. This review focuses on the microbiota in untreated and root-filled canals. It will also describe briefly the recent developments in microbial identification and the mechanisms by which certain species of microbes are able to invade and establish themselves in the root canal.

[Frequency of Candida in root canals of teeth with primary and persistent endodontic infections]

BACKGROUND

Microbiological identification in endodontic infections has focused mainly on bacteria without giving much attention to yeasts, which, due to their virulence factors, can affect the outcomes of root canal treatment.

AIMS

To determine the frequency of Candida in anaerobic conditions in root canals with primary and persistent endodontic infection, as well as to evaluate a microbiological sampling method using aspiration compared to the traditional absorption method with paper points.

METHODS

Fifty microbiological samples were obtained from teeth of 47 patients requiring endodontic treatments, due to either primary or persistent infections. Two microbiological sampling methods were used: an aspiration method, and the traditional paper point absorption method. In each of these methods, two types of medium were used (M₁-M₄). Samples were cultured under anaerobic conditions until reaching 0.5 McFarland turbidity, and then inoculated on Sabouraud dextrose, as well as on anaerobic enriched blood agar plates. Macroscopic and microscopic observations of the colonies were performed. The germ-tube test, growth on CHROMagar, and biochemical identification were performed on the isolated yeasts.

RESULTS

Fungal infection was found in 18 (36%) samples out of the 50 teeth evaluated. In the 18 samples positive for fungal infection, 15 out of 36 (41.6%) teeth were taken from a primary infection, and 3 out of 14 (21.4%) from a persistent infection. The aspiration method using Sabouraud dextrose medium recovered a greater diversity of species.

CONCLUSIONS

Yeasts frequency was higher in teeth with primary infections compared to teeth with persistent infections. The predominant yeast species was Candida albicans. The aspirating sampling method was more efficient in the recovery of Candida isolates than the traditional absorption method.

Fungal periapical abscess and the burn patient: A report of two cases of an unreported source for systemic infection

Fungal infections in the intensive care unit are becoming a more common occurrence, especially in the care of the burn patient. Fungal infections in the critically burned patient, who by nature have a heightened inflammatory state and impaired immune response, have been found to carry a profound degree of morbidity and mortality. We present our experience in the care of severe thermal injuries; a series of patients with endodontic fungal infection which, as we found, pose a significant risk for the development of systemic infection and sepsis. Fungal periapical abscesses are a rare and, yet undescribed, potential source of systemic sepsis in the burn intensive care unit.

Comparison of the Antimicrobial Efficacy of Calcium Hydroxide and Photodynamic Therapy Against Enterococcus faecalis and Candida albicans in Teeth With Periapical Lesions; An In Vivo Study

Introduction: Elimination of pathological microflora of root canal systems is a major goal in endodontic treatment. This study aimed to compare the antimicrobial efficacy of calcium hydroxide as an intracanal medication and antibacterial photodynamic therapy (aPDT) against Enterococcus faecalis and Candida albicans in teeth with periapical (PA) lesions. Methods: This in vivo study was conducted on 20 patients with single-rooted mandibular premolar with previously failed endodontic treatment. This study was performed as a clinical trial (IRCTID: IRCT2016090429686N1). After conventional chemo-mechanical root canal preparation (hand and rotary instruments and 2.5% NaOCl), microbiological samples were obtained using sterile paper points, then stored in thioglycolate solution and transferred to a microbiology laboratory. Group 1 (n = 10) specimens underwent aPDT (diode laser 808 nm + 50 mg/mL methylene blue), while creamy calcium hydroxide paste was used in group 2 for a duration of 1 week. A control sample was taken with sterile paper points and F3 Protaper rotary file. The samples were dispersed in transport medium, serially diluted, and cultured on selective mediums to determine the number of colony forming units (CFUs). Data were analyzed by Mann-Whitney U test at 5% significance level. The significance level for all analyses was set at P < 0.05. Results: Number of CFU significantly decreased in both groups after the interventions (P < 0.001); however, there was no significant difference in the colony count between the 2 groups. Conclusion: aPDT and calcium hydroxide therapy showed the same antimicrobial efficacy on E. faecalis and C. albicans.

Prevalence and nature of fungi in root canal infections: a systematic review and meta-analysis

The role of bacteria in causing apical periodontitis has been widely established, whilst the role of other microorganisms is studied less thoroughly. This systematic review and meta-analysis reviewed the literature for the prevalence and diversity of fungi in root canal infections. An extensive literature search was carried out in the Cochrane databases, EMBASE, MEDLINE, LILACS, SciELO and Web of Science. Additional studies were identified from six endodontic journals, four main endodontic textbooks and references of relevant papers. Selected clinical studies included sampling of necrotic pulps in permanent teeth and microbial analysis of these samples. Studies were critically appraised using the Joanna Briggs Institute Prevalence Critical Appraisal Checklist. Meta-analysis was performed using MetaXL. The screening of 1041 titles and abstracts and full-text reading yielded 54 studies. The overall prevalence of fungi in root canal infections was 7.5% (CI 95%: 3.6-11.8%) in the inverse variance fixed effect heterogeneity model. Candida albicans was the most frequently isolated species. Significant heterogeneity was observed (P < 0.001, I²  = 85.04%). Subgroup analyses based on geographical location, period of publication, type of infection, state of general health, communication with the oral cavity, type of sample and identification method revealed no factor influencing the prevalence. Better standardized techniques and a comprehensive analysis will reveal a more detailed and accurate representation of the prevalence and nature of fungi in root canal infections.

Microbiological Study of Cast Posts before Cementation

This study identifies the most common microorganisms present in type III gold cast posts related to pulpal disease and evaluates the sterilization/disinfection method before cementation in the root canal. Forty-five type III gold cast posts were aseptically collected in sterile sealed plastic bags and taken to the microbiology laboratory to carry out the study: fifteen cast posts had no treatment, fifteen were disinfected (immersion in 70% alcohol during 15 minutes), and fifteen were autoclaved at 121°C for 15 minutes by using saturated steam under 15 psi pressure. By using a two-proportion z-test, the difference was statistically significant (p > 0.05) and demonstrates that, in spite of the aseptic pattern used in the cast post collection and laboratory procedures, some cast posts arrive contaminated at the consulting office. The disinfection process worked out in a high percentage and demonstrated that the sterilization by autoclaving eliminated completely the pathogenic microbiota without affecting the cast post shape and integrity that could compromise their final fitting.

Analysis of bacterial community profiles of endodontically infected primary teeth using pyrosequencing

OBJECTIVE

The purpose of this study was to identify the endodontic microbiome in primary teeth with dental caries using high-throughput pyrosequencing and to establish data on the oral microbiome of primary teeth with endodontic infection.

METHODS

Ten primary teeth with dental caries and endodontic infection were included. Samples were collected from root canals using sterilized paper points and analyzed by pyrosequencing, based on the V1-V3 hypervariable region of the 16S rRNA gene. The data were analyzed using the CLcommunity software.

RESULTS

Analysis of the 10 samples yielded a total of 64,291 16S rRNA gene sequences. In total, 1586 OTUs (range, 91-235), six bacterial phyla, including unclassified, and 187 genera were assigned. At the genus level, Neisseria (group A), Acinetobacter (group B), and Fusobacterium (group C) were prominent. These predominant microorganisms were associated with the clinical condition and reflected the progression of endodontic infection in primary teeth.

CONCLUSIONS

This study revealed a relationship between the oral microbiome and endodontic infection in primary teeth. Additionally, anaerobic bacteria such as Fusobacterium species were dominant in the teeth with apical abscesses.

An in vitro Comparison of Antimicrobial Activity of Three Endodontic Sealers with Different Composition

AIMS

The aim of the study was to compare the antimicrobial property of newly introduced EndoSequence BC sealer with commonly used zinc oxide-eugenol-based sealer (Zical) and epoxy resin-based sealer (MM-Seal) against Candida albicans, Lactobacillus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.

MATERIALS AND METHODS

The agar diffusion test was done to measure the antimicrobial activity of sealers. The sealers were put in the 4 mm wells prepared in the inoculated agar plates. The agar plates were incubated at 37°C for 24 hours and the zones of inhibition that appeared was measured. Chi-square test was done to evaluate intraobserver bias for all study samples. Intergroup comparison was done for all five parameters using Pearson correlation statistical analysis.

RESULTS

EndoSequence BC sealer showed maximum mean of diameter of zones of inhibition against all the microorganisms but with no statistically significant difference with other sealers. Zical did not show any zone of inhibition against the P. aeruginosa. MM-Seal did not show any inhibitory activity against the P. aeruginosa and C. albicans.

CONCLUSION

EndoSequence BC sealer showed antimicrobial activity against all the microorganisms and proved to be a better choice when compared with other two sealers.

CLINICAL SIGNIFICANCE

Antimicrobial properties of endodontic sealers are important to prevent the persistent infection of the complex root canals. EndoSequence BC sealer has been proved to be a better sealer in this aspect.

In vitro comparison of antimicrobial effect of sodium hypochlorite solution and Zataria multiflora essential oil as irrigants in root canals contaminated with Candida albicans

INTRODUCTION

This study compared the antifungal effect of Zataria multiflora essential oil (EO) with that of sodium hypochlorite (NaOCl) as an irrigant for root canals infected with Candida albicans.

MATERIALS AND METHODS

Sixty mandibular premolars were infected with C. albicans suspension. After 72 h of incubation, the samples were divided into four groups. Teeth in Group 1 were irrigated with minimum fungicidal concentration (MFC) of Z. multiflora EO, in Group 2 with twice the MFC of Z. multiflora, in Group 3 with MFC of NaOCl, and in Group 4 with distilled water (DW). Pre- and post-operative samples were cultured, and fungal colony count of each specimen was obtained. Data were analyzed using Kruskal-Wallis and Mann-Whitney tests (P < 0.05).

RESULTS

NaOCl at MFC and Z. multiflora EO at twice the MFC showed the highest antifungal efficacy, with no significant difference (P > 0.05). However, antifungal efficacies of these irrigants were significantly different from those of Z. multiflora EO at MFC and DW (P < 0.05).

CONCLUSION

Our results showed that Z. multiflora EO at twice the MFC had the same antifungal efficacy as NaOCl at MFC.

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.

Innate Immunity and Saliva in Candida albicans-mediated Oral Diseases

The oral cavity is a unique niche where Candida albicans infections occur in immunocompetent as well as immunosuppressed individuals. Here we critically review the significance of human innate immune response in preventing oral candidiasis. One important line of defense against oropharyngeal candidiasis is the oral microbiota that prevents infection by competing for space and nutrients as well as by secreting antagonistic molecules and triggering local inflammatory responses. C. albicans is able to induce mucosal defenses through activation of immune cells and production of cytokines. Also, saliva contains various proteins that affect C. albicans growth positively by promoting mucosal adherence and negatively through immune exclusion and direct fungicidal activity. We further discuss the role of saliva in unifying host innate immune defenses against C. albicans as a communicating medium and how C. albicans overgrowth in the oral cavity may be a result of aberrations ranging from microbial dysbiosis and salivary dysfunction to epithelial damage. Last we underscore select oral diseases in which C. albicans is a contributory microorganism in immune-competent individuals.

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.

Archaea prevalence in inflamed pulp tissues

Archaea have been detected in several ecological niches of the human body such as the large intestine, skin, vagina as well as the oral cavity. At present, archaea are recognized as nonpathogenic microorganisms. However, some data indicate that they may be involved in the etiopathogenesis of several diseases, including intestinal diseases as well as oral diseases: periodontitis, peri-implantitis and endodontitis. In this study, on the basis of 16S rRNA gene sequence analysis, we examined whether archaea might be present in inflamed pulp tissues and contribute to the development of endodontic infection. In comparison, we also determined selected bacterial species associated with endodontitis. We detected archaea in 85% of infected endodontic samples. In addition, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola were present in inflamed pulp tissue samples and Treponema denticola occurred with the highest frequency (70%). Further analysis revealed the presence of methanogenic archaea in analyzed samples. Direct sequencing of archaeal 16S rRNA gene PCR products indicated the occurrence of methanogenic archaea in inflamed pulp tissues; phylogenetically most similar were Methanobrevibacter oralis and Methanobrevibacter smithii. Therefore, our results show that methanogenic archaea are present in inflamed pulp tissues and may participate in the development of endodontic infection.

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.

Microbiologic Evaluation of Matricaria and Chlorhexidine against E. faecalis and C. albicans

Objective:

To evaluate the antimicrobial activity of different concentrations of Matricaria chamomilla and Chlorhexidine gel against Candida albicans and Enterococcus faecalis.

Materials and Methods:

The agar diffusion test was used to evaluate the antimicrobial activity of 15%, 25% Matricaria chamomilla in aq. base and 2% chlorhexidine gel against C. albicans (ATCC 24433) and E. faecalis (ATCC 24212) strains. Vancomycin was used as the positive control for E. faecalis and fluconazole for C. albicans . The agar plates were incubated at 37°C for 48 h after which the zone of inhibition were measured separately for each material. Data thus obtained were statistically analyzed using the Wilcoxon rank–order test.

Results:

2% chlorhexidine showed maximum inhibitory zone for C. albicans (33.26 mm) and E. faecalis (24.54 mm). 25% Matricaria showed zones of 24.16 mm and 20.62 mm for C. albicans and E. faecalis, respectively. 15% Matricaria did not show any antimicrobial activity (0 mm).

Conclusion:

The results of the current in vitro study suggest that 25% Matricaria can be used as an antimicrobial agent, but it is less effective than 2% chlorhexidine gluconate gel against C. albicans and E. faecalis. Matricaria at a lesser concentration of 15% aq. base is ineffective against both the microorganisms.

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.

Differential Proteinase Patterns among Candida albicans Strains Isolated from Root Canal and Lingual Dorsum: Possible Roles in Periapical Disease

INTRODUCTION

Proteinases play pivotal roles in Candida albicans infections. Although the yeast can colonize the pulpal environment, there is no information about the enzymatic profile of this organism. This in vitro study aimed to determine the proteolysis levels and to investigate differences in the expression of aspartyl proteinase genes (Sap 1, Sap 2, and Sap 4) among various root canal strains and clinical isolates from the lingual dorsum.

METHODS

The extracellular proteinase activity of 104 C. albicans samples isolated from the lingual dorsum and from necrotic root canals was measured with respect to bovine serum albumin degradation after 5 days of incubation at 37°C. We used reverse-transcription polymerase chain reaction, a highly sensitive method, to detect messenger RNA transcripts of aspartyl proteinase genes (Sap 1, Sap 2, and Sap 4). The C. albicans strain SC 5314 was used as a positive control for both experiments because it is recognized as being highly proteolytic. All tests were performed in triplicate.

RESULTS

Regardless of the isolation site, all C. albicans strains produced an opaque precipitation halo around the colonies, indicating some proteinase activity. However, the production of proteinase on the plates was significantly greater (P < .05) by the endodontic samples. Sap 2 was the most commonly expressed gene in all samples. Among the root canal samples, the detection of Sap 1 transcripts was always associated with the expression of Sap 2 and Sap 4. Sap 4 gene expression was detected in all root canal samples. The simultaneous expression of the 3 investigated Sap genes (Sap 1, Sap 2, and Sap 4) was more common in strains isolated from the lingual dorsum (50%) than in those isolated from root canals (29.4%).

CONCLUSIONS

The increased proteolytic activity as well as the distinct pattern of Sap expression observed among the root canal samples may suggest a pathogenic role for C. albicans in endodontic infections.

Evaluation of antifungal activity of white-colored mineral trioxide aggregate on different strains of Candida albicans in vitro

AIM

The purpose of this study was to evaluate the antifungal action of various concentrations of white mineral trioxide aggregate (MTA) against seven different strains of Candida albicans using the tube dilution test.

MATERIALS AND METHODS

Fresh mix of MTA was prepared at concentrations of 100, 50, 25, and 12.5 mg/ml and added to a broth tube containing Sabouraud's liquid medium. A total of 1287 broth tubes were prepared and divided into experimental and control groups. Stock cultures of seven strains of C. albicans were obtained. Fresh inoculate of the microorganism was prepared by growing overnight cultures. Aliquots of the test C. albicans were taken and added to the test tubes. All tubes were incubated at 37°C for 1-, 24-, 72-, and 168-h time periods. At each time period, the presence of C. albicans colonies was assessed.

STATISTICAL ANALYSIS USED

Differences among the groups were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

Results showed that one strain showed resistance even after 3 days at the lower MTA concentrations of 12.5 and 25 mg/ml. Growth reoccurred with three strains at MTA concentration of 12.5 mg/ml after 7 days. A significant difference was found between strain 3 and other strains at MTA concentrations of 12.5 and 25 mg/ml at the 3-days time period and between tubes containing 12.5 mg/ml and tubes containing higher concentrations of MTA at the 7-days time period.

CONCLUSION

White MTA in concentrations of 100 and 50 mg/ml is effective in inhibiting the seven tested strains of C. albicans for periods up to 1 week.

Comparison of antimicrobial efficacy of propolis, Morinda citrifolia, Azadirachta indica (Neem) and 5% sodium hypochlorite on Candida albicans biofilm formed on tooth substrate: An in-vitro study

INTRODUCTION

Endodontic infections are polymicrobial in nature. Candida albicans is the most common fungus isolated from failed endodontic cases. The constant increase in antibiotic resistant strains and side-effects caused by synthetic drugs has prompted researchers to look for herbal alternatives such as propolis, Morinda citrifolia and Azadirachta indica (Neem) etc., since, the gold standard for irrigation, i.e., sodium hypochlorite has many disadvantages.

MATERIALS AND METHODS

Extracted human mandibular premolars were biomechanically prepared, vertically sectioned, placed in tissue culture wells exposing the root canal surface to C. albicans grown on Sabouraud Dextrose Agar to form a biofilm. At the end of 2 days, all groups were treated with test solutions and control for 10 min and evaluated for Candida growth and number of colony forming units. The readings were subjected to statistical analysis using analysis of variance and post hoc Tukey tests.

RESULTS

Sodium hypochlorite and propolis groups exhibited highest antimicrobial efficacy against C. albicans with no statistically significant difference. It was followed by the A. indica (Neem) group. M. citrifolia had limited antifungal action followed by the negative control group of saline.

CONCLUSION

According to the results of this study, propolis can be used as an effective antifungal agent similar to that of sodium hypochlorite, although long-term in vivo studies are warranted.

Antifungal activity of several root canal sealers against Candida albicans

OBJECTIVE

The purpose of this in vitro study was to evaluate the antifungal activity of several root canal sealers (iRoot SP, MTA Fillapex and GuttaFlow) against Candida albicans and compare them to that of AH Plus Jet.

MATERIALS AND METHODS

A 10 μL fungi in suspension was allowed to directly contact the sealers, which were freshly mixed or allowed to set for 1 or 7 days. Fresh media was then added and survival of fungi was determined by using 10-fold serial dilution and inoculated onto agar plates. After incubation for 48 h, colony-forming units (CFU) were calculated and their log10 values converted. The data were analyzed using ANOVA and Tukey tests (α = 0.05).

RESULTS

Freshly mixed AH Plus Jet totally inhibited the growth of fungi and showed the highest antifungal activity. GuttaFlow did not show any significant antifungal activity at all times. Freshly mixed iRoot SP and MTA Fillapex were found to be antifungal. Statistical differences were found between freshly mixed and set samples (p < 0.05) in favor of the former, except GuttaFlow. No statistically significant differences were found among the tested sealers at the 1 and 7-day samples (p > 0.05).

CONCLUSIONS

Fresh AH Plus Jet had very potent antifungal activity. All sealers, except GuttaFlow, exhibited antifungal activity when freshly mixed.

Detection of Enterococcus faecalis and Candida albicans in previously root-filled teeth in a population of Gujarat with polymerase chain reaction

BACKGROUND

Micro-organisms are the primary causative agents of endodontic infections. Phenotype based procedures for bacterial identification has certain drawbacks especially, when investigating the microbiota of root-filled teeth. Thus, more sensitive methods like Polymerase chain reaction (PCR) can provide results that are more accurate and reliable for the microbial prevalence in the root filled teeth.

AIM

In this study, we have investigated twenty symptomatic root-filled teeth with chronic apical periodontitis for the prevalence of Enterococcus faecalis and Candida albicans in the root filled teeth associated with symptomatic cases with or without periradicular lesions.

MATERIALS AND METHODS

Microbiological samples were taken from the canals immediately after removal of previous gutta percha cones using aseptic techniques. After removal of root canal filling, samples were obtained with paper points placed in the canal. Paper points were transferred to a cryotube containing "Tris EDTA" buffer and immediately frozen at -20°C.

RESULTS

By PCR amplification of the samples using taxon specific primers, E. faecalis was found to be prevalent species, detected in 65% of the cases and C. albicans was detected in 35% of cases.

CONCLUSION

The results of the study shows that geographical influence and dietary factors might have some role to play in the prevalence of the species like C. albicans and presence of E. faecalis confirming the assertion of previous culture-dependent and independent approaches for the microbiological survey of root filled teeth.