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The objective of this study was to investigate the presence of culturable bacteria, endotoxins (LPS) and lipoteichoic acid (LTA) levels in teeth with normal vital pulp (NVP) with intact crowns (IC) and those with coronal restoration (CR) limited to the enamel level. A total of 20 teeth indicated for endodontic treatment due to prosthetic reasons were selected. Samples were collected from the root canals. The levels of cultivable bacteria, LPS and LTA were assessed. Statistical analyses were performed at significance level set at 5%. None of the teeth presented microbial growth. In the IC group, the LPS levels were limited to the lowest concentration of LPS. On the contrary, higher LPS and LTA levels were detected in teeth with CR. It was concluded that teeth with NVP and IC were negative for bacteria, LPS and LTA; while teeth with CR were positive for bacterial virulence factors., (© 2023 Australian Society of Endodontology Inc.)

Introduction: Infective endocarditis (IE) is an inflammatory disease usually caused by bacteria that enter the bloodstream and establish infections in the inner linings or valves of the heart, including blood vessels. Despite the availability of modern antimicrobial and surgical treatments, IE continues to cause substantial morbidity and mortality. Oral microbiota is considered one of the most significant risk factors for IE. The objective of this study was to evaluate the microbiota present in root canal (RC) and periodontal pocket (PP) clinical samples in cases with combined endo-periodontal lesions (EPL) to detect species related to IE using NGS., Methods: Microbial samples were collected from 15 RCs and their associated PPs, also from 05 RCs with vital pulp tissues (negative control, NC). Genomic studies associated with bioinformatics, combined with structuring of a database (genetic sequences of bacteria reported for infective endocarditis), allowed for the assessment of the microbial community at both sites. Functional prediction was conducted using PICRUSt2., Results: Parvimonas, Streptococcus, and Enterococcus were the major genera detected in the RCs and PPs. A total of 79, 96, and 11 species were identified in the RCs, PPs, and NCs, respectively. From them, a total of 34 species from RCs, 53 from PPs, and 2 from NCs were related to IE. Functional inference demonstrated that CR and PP microbiological profiles may not be the only risk factors for IE but may also be associated with systemic diseases, including myocarditis, human cytomegalovirus infection, bacterial invasion of epithelial cells, Huntington's disease, amyotrophic lateral sclerosis, and hypertrophic cardiomyopathy. Additionally, it was possible to predict antimicrobial resistance variants for broad-spectrum drugs, including ampicillin, tetracycline, and macrolides., Conclusion: Microorganisms present in the combined EPL may not be the only risk factor for IE but also for systemic diseases. Antimicrobial resistance variants for broad-spectrum drugs were inferred based on PICRUSt-2. State-of-the-art sequencing combined with bioinformatics has proven to be a powerful tool for conducting studies on microbial communities and could considerably assist in the diagnosis of serious infections., Clinical Relevance: Few studies have investigated the microbiota in teeth compromised by combined endo-periodontal lesions (EPL), but none have correlated the microbiological findings to any systemic condition, particularly IE, using NGS techniques. In such cases, the presence of apical periodontitis and periodontal disease can increase IE risk in susceptible patients., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aim: To comparatively analyse the levels of culturable bacteria, endotoxins (LPS), tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and substance P in teeth with symptomatic irreversible pulpitis (SIP) and vital normal pulp (VNP) tissues., Methodology: Thirty-two patients were included (20 teeth with SIP and 12 teeth with VNP tissues) in this cross-sectional study. Samples were collected from the full length of the root canals (microbial analysis) and periapical tissues (2 mm beyond the apex for immunological analysis), using sterile absorbent paper points. The levels of culturable bacteria (culture method), endotoxins (LAL Pyrogent 5000), TNF-α, IL-1β and substance P (ELISA) were assessed. The Mann-Whitney test was used for comparisons between the levels of CFU/mL, LPS, TNF-α, IL-1β and substance P in the SIP and VNP groups. The statistical analysis was performed with the significance level set at 5%., Results: Culturable bacteria were recovered from all teeth with SIP. On the other hand, no positive cultures were observed in the VNP tissues group (p > .05). The levels of LPS were approximately four times higher in teeth with SIP than in teeth with VNP tissues (p < .05). Higher levels of TNF-α and substance P were detected in teeth with SIP (p < .05). On the other hand, no difference in the levels of IL-1β was detected between the two groups (p > .05)., Conclusion: Teeth with symptomatic irreversible pulpitis present higher levels of culturable bacteria, endotoxins, TNF-α and substance P than those with vital normal pulp tissues. On the other hand, the levels of IL-1β were similar in teeth from both groups suggesting reduced implications of this inflammatory mediator in the early stages of infection., (© 2023 British Endodontic Society. Published by John Wiley & Sons Ltd.)

Aim: To evaluate in a clinical trial the efficacy of reciprocating and ultrasonic activation of 6% sodium hypochlorite (NaOCl) in the microbial composition and reduction in microbial load as well as in levels of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) in teeth with primary endodontic infections., Methodology: Samples were collected from 24 root canals with pulp necrosis and periapical lesions, before and after chemo-mechanical canal preparation. The teeth were randomly divided according to the activation protocol as follows: control group without activation (WA, n = 8), reciprocating activation group using Easy Clean tip (EC, n = 8) and ultrasonic activation group using Irrisonic insert (US, n = 8). Microbiological specimens were processed using a culture technique and microbiota composition was analysed using the checkerboard technique. The levels of LPS and LTA were quantified using limulus amebocyte lysate (LAL) and enzyme-linked immunosorbent assay (ELISA), respectively. The Fisher's exact test, Kruskal-Wallis, Dunn's and Wilcoxon's test with a significance level of P < 0.05 were used for statistical analysis., Results: All initial specimens had growth of viable bacteria in fastidious anaerobe agar (FAA), with an average of 10 5  CFU mL -1 , whereas only one case had such growth after chemo-mechanical canal preparation. LPS and LTA were recovered in 100% of the cases. Chemo-mechanical canal preparation significantly decreased the levels of LPS and LTA (P < 0.05), but no significant differences were found between the groups (P > 0.05). Through the checkerboard technique, bacteria were found in 100% of the initial specimens with concentrations between <10 5 and 10 6 . The most frequently identified microorganisms were Prevotella nigrescens and Enterococcus hirae. After chemo-mechanical canal preparation, many species were not detected in any of the three groups tested. A significant reduction occurred in Group US, followed by Groups EC and WA., Conclusions: Activation of 6% NaOCl reduced the levels of LPS and LTA with no differences between the groups. However, ultrasonic activation was associated with a greater reduction in microbial load within root canals., (© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd.)