Detection of Streptococcus mutans in symptomatic and asymptomatic infected root canals

Leaf Extracts of Moringa oleifera Cultivated in Baghdad: Characterization and Antimicrobial Potential against Endodontic Pathogens

The use of medicinal plant preparations to clean and disinfect root canal infection is gaining popularity. The aim of this study was to evaluate the bioactive composition of leaf extracts of Moringa oleifera plants cultivated in Iraq (specifically Baghdad) and their antimicrobial activity against selected root canal pathogens for potential application in endodontic treatment. Materials and Methods. Moringa leaf extracts were prepared either through cold maceration or warm digestion techniques to perform an ethanolic or aqueous extraction, respectively. Phytochemical detection was performed before thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) to measure flavonoids and phenolic compounds within both extracts. Then, their antimicrobial activities were investigated against Streptococcus mutans, Enterococcus faecalis, and Candida albicans through minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), and agar well diffusion assay in comparison to NaOCl and Ca(OH)2. Results. Phytochemical screening showed several active ingredients but with higher expression of flavonoids and phenolic compounds. Also, different types of these compounds were detected through TLC and quantified by HPLC. MIC values for ethanolic extract against Streptococcus mutans, Enterococcus faecalis, and Candida albicans were 60, 65, and 55, respectively, while for aqueous extract, MIC values were 70, 80, and 50, respectively. Aqueous extract showed a higher inhibition zone than ethanolic extract for both Streptococcus mutans and Enterococcus faecalis with a statistically significant difference (p ≤ 0.001) for all tested materials except with NaOCl and Ca(OH)2 in Streptococcus mutans and Enterococcus faecalis, respectively. The ethanolic extract showed a higher inhibition zone against Candida albicans, with a statistically significant difference (p ≤ 0.001) for all tested materials. Conclusion. Ethanolic and aqueous extracts of Moringa oleifera leaves cultivated in Baghdad contain considerable quantities of phytochemicals, especially flavonoid and phenolic compounds, and demonstrated antimicrobial activities against selected endodontic pathogens. Therefore, Moringa leaf extracts could be suggested as an alternative antimicrobial material in endodontic treatment.

Dental pathologies of endodontic origin and subsequent bacterial involvement - a literature review

Dental pathologies of endodontic origin are varied in nature, and include infectious and non-infectious causes. Through this review, we aim to provide a deeper understanding of the role of bacterial involvement and in the pathogenesis of endodontic pathologies, by reviewing the relevant literature on the most common bacterial species involved, and their capacity to organize as biofilms. Furthermore, we focus on the most important recent updates in the management of endodontic infections, from a multidisciplinary perspective.

One-Pot Preparation of Cetylpyridinium Chloride-Containing Nanoparticles for Biofilm Eradication

Quaternary ammonium compounds (QACs) have been widely used due to their excellent antimicrobial activity. However, using the technology where nanomaterials are employed as drug carriers to deliver QAC drugs has not been fully explored. In this study, mesoporous silica nanoparticles (MSNs) with short rod morphology were synthesized in a one-pot reaction using an antiseptic drug cetylpyridinium chloride (CPC). CPC-MSN were characterized via various methods and tested against three bacterial species (Streptococcus mutans, Actinomyces naeslundii, and Enterococcus faecalis), which are associated with oral infections, caries, and endodontic pathology. The nanoparticle delivery system used in this study prolonged the release of CPC. The manufactured CPC-MSN effectively killed the tested bacteria within the biofilm, and their size allowed them to penetrate into dentinal tubules. This CPC-MSN nanoparticle delivery system demonstrates potential for applications in dental materials.

Comparison of antibacterial effect of plantaricin 149 suspension and traditional root canal irrigation solutions in root canal infections in vitro

Dental pulp and periapical diseases are common conditions in stomatology, caused by various pathogenic microorganisms. Antimicrobial peptides, as new antibiotics, offer promising applications in the irrigation and disinfection medicaments for root canals.One patient with chronic periapical periodontitis was selected to extract the clinical pathogenic bacteria. Porphyromonas gingivalis (Pg) (ATCC 33,277), Streptococcus mutans (Sm) (ATCC 25,175), and Prevotella intermedius (Pi) (ATCC 25,611) were used as test strains. The effects of plantaricin (Pln) 149 on the biofilm formation and growth in infected root canals were evaluated by RT-PCR, laser confocal scanning microscopy, and bacterial diversity analysis. In addition, the cytotoxicity of Pln 149 (100 µg/mL) to human dental pulp stem cells (hDPSCs) was assessed using an MTT assay. Pln 149 exhibited significant inhibitory effects on Pg Sm and Pi (P < 0.05), with significant differences in the biofilm images of the laser confocal scanning microscope (P < 0.05). There were no significant differences in hDPSCs viability or proliferation between the Pln 149 and control groups. Considering the excellent antimicrobial effects and low cytotoxicity, we suggest that Pln 149 might be a promising option for root canal irrigation solutions.

Potential relationship between clinical symptoms and the root canal microbiomes of root filled teeth based on the next-generation sequencing

AIM

To determine the microorganism in root canal systems of root filled teeth with periapical disease and their relationship with clinical symptoms using next-generation sequencing.

METHODOLOGY

The roots of 10 extracted teeth were collected from 10 patients who presented with post-treatment apical periodontitis (PTAP; six with symptoms and four without symptoms). Each root was divided horizontally into two parts (apical and coronal segments) and cryo-pulverized. Microbial communities were detected using 16S rDNA hypervariable V3-V4 region. The diversity, principal coordinate analysis and linear discriminant analysis effect size were performed in the symptomatic and asymptomatic groups (apical and coronal parts respectively). A Mann-Whitney test and an analysis of similarities were applied for intergroup analysis, at a significance level of 5%.

RESULTS

A total of 23 phyla, 257 genera and 425 species were detected. Firmicutes was the most abundant phylum in all samples. Three phyla (Fusobacteria, Synergistetes and unidentified_Bacteria) and seven genera (Fusobacterium, Porphyromonas, Phocaeicola, Olsenella, Campylobacter, Tannerella and Fretibacterium) were significantly more abundant in the symptomatic patients (p < .05), whereas asymptomatic patients had more Sphingomonas. The species more significantly abundant in the symptomatic samples were Porphyromonas gingivalis, Phocaeicola abscessus, Campylobacter showae, Tannerella forsythia and Olsenella uli (p < .05).

CONCLUSIONS

A greater microbial diversity was observed in root filled teeth with PTAP compared to earlier reports. Several genera and species in root canal systems might be associated with clinical symptoms of PTAP.

Antibacterial Activity of Copper Nanoparticles (CuNPs) against a Resistant Calcium Hydroxide Multispecies Endodontic Biofilm

Endodontic treatment reduces the amount of bacteria by using antimicrobial agents to favor healing. However, disinfecting all of the canal system is difficult due to its anatomical complexity and may result in endodontic failure. Copper nanoparticles have antimicrobial activity against diverse microorganisms, especially to resistant strains, and offer a potential alternative for disinfection during endodontic therapy. This study evaluated the antibacterial action of copper nanoparticles (CuNPs) on an ex vivo multispecies biofilm using plaque count compared to the antibacterial activity of calcium hydroxide Ca(OH)₂. There were significant differences between the Ca(OH)₂ and CuNPs groups as an intracanal dressing compared with the CuNPs groups as an irrigation solution (p < 0.0001). An increase in the count of the group exposed to 7 days of Ca(OH)₂ was observed compared to the group exposed to Ca(OH)₂ for 1 day. These findings differ from what was observed with CuNPs in the same period of time. Antibacterial activity of CuNPs was observed on a multispecies biofilm, detecting an immediate action and over-time effect, gradually reaching their highest efficacy on day 7 after application. The latter raises the possibility of the emergence of Ca(OH)₂-resistant strains and supports the use of CuNPs as alternative intracanal medication.

Antimicrobial Activity of Calcium Silicate-Based Dental Materials: A Literature Review

Endodontic biomaterials have significantly improved dental treatment techniques in several aspects now that they can be used for vital pulp treatments, as temporary intracanal medication, in definitive fillings, in apical surgeries, and for regenerative procedures. Calcium silicate-based cement is a class of dental material that is used in endodontics in direct contact with the dental structures, connective tissue, and bone. Because the material interacts with biological tissues and stimulates biomineralization processes, its properties are of major importance. The main challenge in endodontic treatments is the elimination of biofilms that are present in the root canal system anatomical complexities, as it remains even after chemical-mechanical preparation and disinfection procedures. Thus, an additional challenge for these biomaterials is to exert antimicrobial activity while maintaining their biological properties in parallel. This article reviews the literature for studies considering the antimicrobial properties of calcium silicate-based dental biomaterials used in endodontic practice. Considering the reviewed studies, it can be affirmed that the reduced antimicrobial effect exhibited by calcium silicate-based endodontic materials clearly emphasizes that all clinical procedures prior to their use must be carefully performed. Future studies for the evaluation of these materials, and especially newly proposed materials, under poly-microbial biofilms associated with endodontic diseases will be necessary.

Cerebral microbleeds in vascular dementia from clinical aspects to host-microbial interaction

Vascular dementia is the second leading cause of dementia after Alzheimer's disease in the elderly population worldwide. Cerebral microbleeds (CMBs) are frequently observed in MRI of elderly subjects and considered as a possible surrogate marker. The number and location of CMBs reflect the severity of diseases and the underlying pathologies may involve cerebral amyloid angiopathy or hypertensive vasculopathy. Accumulating evidence demonstrated the clinicopathological discrepancies of CMBs, the clinical significance of CMBs associated with other MRI markers of cerebral small vessel disease, cognitive impairments, serum, and cerebrospinal fluid biomarkers. Moreover, emerging evidence has shown that genetic factors and gene-environmental interactions might shed light on the underlying etiologies of CMBs, focusing on blood-brain-barrier and inflammation. In this review, we introduce recent genetic and microbiome studies as a cutting-edge approach to figure out the etiology of CMBs through the "microbe-brain-oral axis" and "microbiome-brain-gut axis." Finally, we propose novel concepts, "microvascular matrisome" and "imbalanced proteostasis," which may provide better perspectives for elucidating the pathophysiology of CMBs and future development of therapeutics for vascular dementia using CMBs as a surrogate marker.