Search Results (165)

Dental caries is a multifactorial chronic infectious disease that impacts healthcare costs globally, caused by alterations of the plaque microbiome and proliferation of cariogenic Streptococcus mutans. Treatments targeting S. mutans, such as alternative strategies using probiotics, might be effective in preventing the development of dental caries. In this study, the probiotic formulation of Lactobacillus reuteri SGL01, vitamin C, and acerola was tested against S. mutans DSM20523. Antimicrobial activity was assessed by deferred antagonism and spot-on-lawn assays for L. reuteri SGL01. MIC and MBC of L. reuteri SGL01 cell-free supernatant (CFS), vitamin C, and acerola were determined with the microdilution method. Time–kill assays determined the bactericidal kinetics for each compound. The checkerboard method was used to evaluate the potential synergistic activity of CFS–vitamin C or CFS–acerola at scalar dilutions from 1 to 8X MIC. Lastly, antibiofilm activity was tested for each compound. Antimicrobial activity of L. reuteri SGL01 was first assessed by classic methods. MIC and MBC values differed for one dilution for all compounds, with values of 25% and 50% for CFS, 9.3 mg/mL and 18.7 mg/mL for vitamin C, and 18.7 mg/mL and 37.5 mg/mL for acerola, respectively. Moreover, time–kill assays confirmed the bactericidal activity at different timepoints: 4 h for CFS, 6 h for vitamin C, and 24 h for acerola. The fractional inhibitory concentration index (FICI) showed indifference for all combinations, and for associations tested at 2, 4, and 8XMIC. S. mutans biofilm production was impaired for all components, with stronger activity by vitamin C and acerola at lower concentrations. The probiotic formulation containing L. reuteri SGl01, vitamin C, and acerola extract exerts a bactericidal effect, especially strong for the CFS, as well as antibiofilm activity. Thus, the combination of these three components could be advantageous for their complementary effects, with use as a novel treatment against the development of dental caries by S. mutans. Full article

The oral cavity contains several microbial niches, including saliva, dental plaque and tongue coating, each shaped by distinct local environments and host factors. This study compared the ecological and functional characteristics of the microbiomes of these three oral sites within the same individuals and examined host conditions associated with their variation. Saliva, supragingival plaque and tongue coating samples were collected simultaneously from 31 adults without clinical oral lesions. The bacterial 16S rRNA gene (V3–V4 region) was sequenced using the Illumina MiSeq platform, and analyses included α and β diversity, Mantel correlations, differential abundance tests, network analysis and functional prediction. The three sites displayed a clear ecological gradient. Saliva and tongue coating were taxonomically similar but were influenced by different host factors, whereas plaque maintained a distinct, biofilm-like structure with limited systemic influence. Functional divergence was most pronounced on the tongue coating despite its taxonomic similarity to saliva, whereas functional differences between saliva and plaque were modest despite larger taxonomic separation. These findings indicate that microbial composition and function vary independently across oral niches and support the need for multi-site sampling to more accurately characterize oral microbial ecology. Full article

Background/Objectives: Streptococcus mutans (S. mutans) is a primary cariogenic bacterium contributing to biofilm acidogenicity and enamel demineralization. Conventional caries prevention relies mainly on mechanical plaque control and dietary modification, but probiotics have emerged as potential adjuncts for oral microbiota modulation. This pilot randomized controlled trial aimed to evaluate the short-term effects of a multi-strain probiotic containing Lactobacillus and Bifidobacterium on clinical and microbiological parameters associated with dental caries in children. Methods: A double-blind, randomized, placebo-controlled clinical trial was conducted in 40 children aged 6–14 years from a community setting. Participants were randomly allocated (1:1) to receive either probiotic or placebo lozenges for 30 days. Clinical assessments included the Gingival Index (GI), Plaque Index (PI), International Caries Detection and Assessment System (ICDAS), salivary pH, buffering capacity, and salivary S. mutans concentration. The study was preregistered (10.17605/OSF.IO/GKVUW) and ethically approved. Results: The intervention was well tolerated, with no adverse events reported and high participant acceptability. Despite there being no statistically significant differences in any clinical or microbiological parameter (p > 0.05), we found trends toward higher salivary pH, improved buffering capacity, and reduced S. mutans counts in the probiotic group. Conclusions: Short-term probiotic supplementation was safe and well accepted among children but did not produce statistically significant improvements in oral health parameters over 30 days. These findings highlight the feasibility of probiotic use in pediatric populations and support the need for larger, longer-term trials to clarify their potential role as adjuncts in caries prevention. Full article

The interaction between human salivary alpha-amylase (HSAmy) and amylase-binding oral streptococci (ABS) helps determine the bacteria that colonize the oral cavity by establishing dental biofilms. Streptococci are important pioneer species of the oral cavity and influence oral health as well as common diseases such as dental caries. Various oral streptococcal species express distinct amylase-binding proteins, among which amylase-binding protein A (AbpA), encoded by the abpA gene in Streptococcus gordonii and several other species, which is the most extensively studied. Amylase binding facilitates microbial adhesion to host surfaces and biofilm formation and enables bacteria to harness the host’s amylase enzymatic activity at their cell surface, enhancing their capacity to metabolize dietary starch for nutritional gain. Additionally, amylase binding may also influence bacterial cell division and stress tolerance by engaging novel bacterial signaling pathways. From an evolutionary perspective, both Neanderthals and modern humans exhibit functional adaptations in nutrient metabolism, including selection for salivary amylase-binding oral streptococci, highlighting the importance of microbial co-adaptation in response to host diet. Further research is warranted to elucidate the broader roles of amylase binding to bacteria in host-bacterial signaling, bacterial cell division and fitness and the evolutionary trajectory of the oral microbiome. Full article

Background/Objectives: The use of cannabidiol (CBD) as an antimicrobial and antifungal agent has gained interest in medicine, with studies suggesting potential against various microorganisms. However, its effectiveness against oral pathogens remains underexplored in dental research, highlighting the need for further studies. This scoping review summarizes current evidence on the antimicrobial properties of CBD in dental and oral health. Methods: A systematic search was conducted across seven databases (PubMed, the Cochrane Library, Scopus, Embase, Web of Science, SciELO, and LILACS) up to January 2025. The inclusion criteria encompassed studies that explored the effects of CBD on oral microbiology (in vitro and in vivo in animal models), regardless of language or year of publication. The gray literature was evaluated in the Google Scholar database. Results: A total of 1284 articles were identified, of which 10 met the inclusion criteria for this scoping review. These studies, published between 2019 and 2025, primarily focused on bacterial and fungal cultures. The most commonly used methods were the minimum inhibitory concentration test and counting colony-forming units. The contact methods between CBD and bacterial/fungal cell cultures were either dilution or direct contact. Conclusions: CBD shows promising antimicrobial properties against a range of oral bacteria and fungi, suggesting its potential application in managing oral health conditions. Full article

Background and objectives: Atherosclerotic cardiovascular disease (ASCVD) remains a major global cause of mortality, with chronic infections and systemic inflammation, including those arising from periodontal pathogens, contributing to vascular pathology. This study aims to investigate the presence of bacterial DNA from oral cavity microorganisms in atherosclerotic plaques of patients with abdominal aortic aneurysm (AAA) and to explore correlations with oral health indices and clinical variables. Materials and Methods: Forty patients (mean age 61 ± 6 years; 60% male) with periodontitis and AAA were included. Subgingival biofilm and arterial plaque samples were analyzed using PCR for A. actinomycetemcomitans, P. gingivalis, P. intermedia, T. forsythensis, and T. denticola. Dental indices (PI, GI, SBI, and PPD) were determined in all patients, and concordance of the findings was assessed by Cohen’s κ, and correlations were evaluated using Spearman’s coefficient. Results: P. gingivalis exhibited the highest concordance between oral and arterial plaques, followed by T. forsythensis and A. actinomycetemcomitans. T. denticola DNA was not detected in aortic samples. Positive correlations found between A. actinomycetemcomitans and P. gingivalis with dental indices were found to be statistically significant. Conclusions: The detection of periodontal pathogens, particularly P. gingivalis and T. forsythensis, in both oral and arterial plaques supports their potential role in atherosclerotic and aneurysmal changes. The findings highlight the relevance of periodontal health in cardiovascular risk prevention and the need for longitudinal studies to reveal causal mechanisms. Full article

Periodontitis is a chronic inflammatory disease of the periodontal tissues primarily caused by dysbiotic bacterial communities. Accumulating evidence suggests that periodontal pathogens not only drive the initiation and progression of periodontitis but also significantly contribute to systemic disorders, including diabetes mellitus, cardiovascular disease, cancer, and adverse pregnancy outcomes, such as preterm birth. The key periodontal pathogens implicated in disease pathogenesis include Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. Among the diverse factors governing bacterial colonization and biofilm formation, interspecies interactions, particularly coaggregation, play a critical role in dental plaque maturation and the establishment of pathogenic microbial communities. Coaggregation facilitates the spatial organization of bacteria within biofilms, enhances bacterial survival, and modulates virulence factor expression. This review summarizes current knowledge regarding bacterial interactions involving major periodontal pathogens, with particular emphasis on coaggregation mechanisms, and discusses the implications of this coaggregation for periodontitis pathogenesis and associated systemic diseases. Full article

Objectives: This systematic review aimed to evaluate the association between oral health—particularly dental caries and dysbiosis of the oral microbiome—and respiratory diseases across different age groups and clinical settings, with emphasis on microbial overlap, clinical outcomes, and preventive strategies. Methods: A systematic search was conducted in PubMed, Scopus, Embase, Web of Science, and the Cochrane Library up to June 2025. Eligible studies included randomized controlled trials, cohort, case–control, and cross-sectional investigations examining the relationship between oral diseases or microbiome alterations and respiratory outcomes. Data on study design, population, oral health parameters, microbial taxa, and respiratory endpoints were extracted. Study quality was assessed using the Mixed Methods Appraisal Tool (MMAT, 2018). Results: Twenty studies met the inclusion criteria, encompassing pediatric, adult, and elderly populations. Poor oral health, reflected by higher caries indices and periodontal inflammation, was consistently associated with increased risk of lower respiratory tract infections (LRTI), aspiration events, ventilator-associated pneumonia (VAP), and impaired pulmonary function. Oral microbiome analyses revealed enrichment of Veillonella, Prevotella, Klebsiella, and Pseudomonas species in both oral and airway samples, supporting the oral cavity as a reservoir for respiratory pathogens. Interventional evidence from intensive care and nursing home settings demonstrated that structured oral care—particularly daily toothbrushing and chlorhexidine-based plaque control—significantly reduced pneumonia incidence. Conclusions: This review confirms a clinically relevant and biologically plausible link between oral dysbiosis, dental caries, and respiratory disease. Oral biofilms contribute to infection risk through microaspiration and microbial seeding of the lower airways. Integrating oral screening, hygiene maintenance, and treatment of active oral disease into respiratory care pathways may reduce respiratory morbidity and mortality, particularly among high-risk populations such as ICU patients, older adults, and individuals with chronic lung disease. Full article

Dental caries is a major global health concern, with Streptococcus mutans playing a key role in biofilm formation and acid production, which lead to enamel demineralization. Natural products, particularly plant-derived extracts, offer promising alternatives to conventional antibacterial agents. This study aimed to analyze the chemical composition of Ferula varia 70% ethanol extract (FVE) and evaluate its potential to inhibit biofilm formation by S. mutans. The aerial parts of F. varia were extracted with 70% ethanol and analyzed using LC-UV-ESI-MS/MS to determine the chemical profile. The anti-biofilm activity of FVE was evaluated using a crystal violet assay against S. mutans. Phytochemical analysis identified 14 compounds, including major phenolic acids (e.g., chlorogenic acid, gallic acid) and flavonoids (e.g., isoquercitrin, isorhamnetin-3-O-glucoside). FVE exhibited significant, dose-dependent inhibition of S. mutans biofilm formation. Importantly, the FVE concentration of 5 mg/mL inhibited S. mutans biofilm development by 100%. The potent antibiofilm activity of FVE against S. mutans is likely due to the synergistic action of its rich content of phenolic acids and flavonoids, which possess known anti-virulence properties. These findings support the potential use of FVE as a natural ingredient in oral hygiene products to prevent dental plaque and caries. Full article

Background and Objectives: Orthodontic auxiliaries create plaque-retentive niches that may amplify biofilm accumulation and inflame adjacent soft tissues. While cross-sectional comparisons suggest higher palatal burden beneath acrylic elements, less is known about real-world patterns accumulated across years of routine care. We retrospectively evaluated periodontal and palatal outcomes, and, in a microbiology sub-sample, site-specific colonization, across three device types: molar bands, Nance buttons, and removable acrylic plates. Methods: We reviewed 2022–2025 records from a university orthodontic service, including consecutive patients aged 18–30 years with documented pre-placement and 6-month follow-up indices. Groups were bands (n = 92), Nance (n = 78), acrylic (n = 76). Standardized charted measures were abstracted: Plaque Index (PI), Gingival Index (GI), bleeding on probing (BOP%), probing depth (PD), and palatal erythema grade (0–3). A laboratory sub-sample (n = 174 visits) had archived swabs cultured for total aerobic counts (log₁₀ CFU/cm²) at the device, adjacent enamel, and palatal mucosa; Streptococcus mutans burden was available from qPCR (log₁₀ copies/mL). Results: Baseline characteristics were similar, except for longer wear at follow-up in Nance (10.1 ± 4.0 months) vs. bands (8.7 ± 3.2) and acrylic (6.9 ± 3.0; p < 0.001). At 6 months, device type was associated with greater worsening of PI and GI (both p < 0.001) and with higher palatal erythema (bands 0.7 ± 0.5; Nance 1.6 ± 0.8; acrylic 1.9 ± 0.7; p < 0.001). Microbiologically, palatal mucosal colonization was lowest with bands (3.3 ± 0.5), higher with Nance (4.9 ± 0.6), and highest with acrylic (5.0 ± 0.7; p < 0.001); S. mutans mirrored this gradient (p < 0.001). Palatal CFU correlated with erythema (ρ = 0.6, p < 0.001) and ΔGI (ρ = 0.5, p < 0.001). In adjusted models, acrylic (OR 6.7, 95% CI 3.5–12.8) and Nance (OR 4.9, 2.5–9.3) independently predicted erythema ≥2; recent prophylaxis reduced odds (OR 0.6, 0.3–0.9). Conclusions: In this single-center cohort, palate-contacting designs were associated with higher palatal biomass and erythema than bands. These associations support device-tailored hygiene considerations and proactive palatal surveillance, particularly for acrylic components. Full article

Background: This study aimed to evaluate the effectiveness of xylitol- and fluoride-containing chewing gum in reducing dental plaque using a novel 3D colorimetric analysis, and to compare results with the Plaque Control Record (PCR). Methods: An acute intervention study was conducted on 34 healthy adults (18–45 years). A plaque-disclosing solution was applied, and intraoral scans were taken before and after 15 min of gum mastication. Plaque was quantified with PCR and the Placca Read software, which analyzes colorimetric patterns of scanned images. Statistical analyses (Shapiro–Wilk test, paired t-test) were performed with Jamovi Software version 1.6.14. Results: A significant reduction in plaque scores was observed after chewing gum (p < 0.05). Mean reduction reached −14.8% in the experimental group versus −3.9% in controls, where natural saliva flow and pigment washout may explain the modest decline. The 3D analysis provided precise measurements across all dental surfaces and showed strong correlation with PCR, supporting its validity. Conclusions: These findings indicate that functional chewing gum can significantly reduce plaque accumulation even after a single use, and that 3D colorimetric analysis offers a reliable, comprehensive alternative to conventional indices. Full article

In the pursuit of addressing the persistent challenge of bacterial adhesion and biofilm formation in dental care, this study investigates the efficacy of electric current as an alternative strategy, specifically focusing on its application in dental contexts. Polyether ether ketone (PEEK), known for its excellent biocompatibility and resistance to bacterial plaque, was enhanced with conductive properties by incorporating silver (Ag), a well-known antibacterial material. Through systematic in vitro experiments, the effectiveness of alternating current (AC) and direct current (DC) in reducing bacterial proliferation was evaluated. The tests were conducted using two bacterial strains: the Gram-positive Staphylococcus aureus and the Gram-negative Pseudomonas aeruginosa. Various configurations, current parameters, and two different electrode configurations were assessed to determine their impact on bacterial reduction. A notable finding from this study is that alternating current (AC) demonstrates superior efficacy compared to direct current (DC). The more significant decrease in CFUs/mL for P. aeruginosa with AC was recorded at the current levels of 5 mA and 500 nA. In opposition, S. aureus exhibited the greatest reduction at 5 mA and 1 mA. This study highlights the potential of using electric current within specific intensity ranges as an alternative strategy to effectively mitigate bacterial challenges in dental care. Full article

Dental caries, a prevalent biofilm-mediated chronic disease, causes enamel demineralization, pulp infection, and systemic complications. Dental plaque biofilm is the initiating factor for the occurrence and development of caries. Streptococcus mutans is an opportunistic pathogen linked to the structure and ecology of dental plaque biofilms. The molecular mechanism of S. mutans during biofilm ontogeny in driving cariogenesis has been extensively elucidated. Here, we observed that asiatic acid is a potent biofilm disruptor that selectively dismantles S. mutans biofilm architectures, prompting us to investigate its mechanism. The minimum biofilm inhibition concentration (MBIC) of asiatic acid on S. mutans was 62.5 μM, but the MBIC level did not substantially impede planktonic growth. Using the static active-attachment model, it was demonstrated that asiatic acid significantly reduced biofilm biomass (p < 0.001) and extracellular polysaccharides (EPS) content (p < 0.001), while concurrently diminishing acid production (p = 0.017) and metabolic activity (p = 0.014). Confocal and scanning electron microscopy further confirmed structural disintegration, including bacterial detachment and reduced biofilm thickness. Transcriptome analysis of S. mutans biofilm treated with asiatic acid revealed 454 differentially expressed genes (adjusted p < 0.05, |log₂FC| ≥ 1). Notably, genes related to the CiaRH two-component system (ciaR, ciaH), a central regulatory hub for biofilm maturation and acid tolerance. This disruption initiates a downstream cascade, causing a coordinated downregulation of critical gene clusters essential for virulence and pathogenesis, including stress response (htrA, clpP, groEL, dnaK), and the glucan-binding protein gene (gbpC) essential for biofilm structural integrity. These findings provide the first mechanistic evidence linking asiatic acid to transcriptional reprogramming in S. mutans biofilm, offering a novel ecological strategy for caries prevention by targeting key regulatory pathways. Full article

Background: Orthodontic auxiliaries can create plaque-retentive niches that inflame adjacent soft tissues. We compared bacterial colonization on molar bands, Nance buttons, and acrylic plates and assessed associated periodontal and palatal tissue responses in adolescents. Methods: In a cross-sectional study (n = 128; 10–17 years), clinical indices (Plaque Index, Gingival Index, bleeding on probing, probing depth) were recorded at device-influenced teeth. Palatal fibromucosa under palate-contacting devices was graded 0–3 (0 = none, 1 = mild/diffuse, 2 = moderate/confluent, 3 = marked with papillary hyperemia). Swabs from device surfaces, adjacent enamel, and palatal mucosa were cultured for total aerobic counts (log₁₀ CFU/cm²); Streptococcus mutans burden was quantified by qPCR (log₁₀ copies/mL). Group differences and adjusted associations were analyzed. Results: Palate-contacting devices harbored greater palatal biofilm and presented higher soft-tissue inflammation than bands. In adjusted models, device type (Nance, acrylic) remained associated with higher Gingival Index independent of measured behaviors and wear duration. Palatal colonization tracked closely with palatal erythema, supporting a local dose–response at the palatal interface. Conclusions: Appliance design is associated with distinct colonization patterns and soft-tissue responses; palate-covering acrylic components warrant device-specific hygiene and routine palatal inspection. Selecting designs with better cleansability and reinforcing plate-specific cleaning may mitigate palatal inflammation during treatment. Full article

Background/Objectives: Dental plaque, a biofilm composed of accumulated oral microorganisms, is a key contributor to various oral diseases. 6-shogaol, a bioactive compound of ginger, is known to have pharmacological activities, including anticancer, anti-inflammatory, and antimicrobial activities. Therefore, we aimed to determine the effects of 6-shogaol on dual-species biofilms of Streptococcus mutans (S. mutans) and Candida albicans (C. albicans). Methods: Dual-species oral biofilms were formed on hydroxyapatite (HA) disks for 42 h and exposed to 6-shogaol. The pH was measured in the experimental medium, and the biomass, colony-forming unit (CFU) of microbial cells, and insoluble extracellular polysaccharides (EPS) were quantified in the biofilm formed on the HA disk. Confocal laser scanning microscopy (CLSM) was used to assess biofilm morphology, and quantitative polymerase chain reaction was performed to analyze gtf gene expression. Results: 6-shogaol dose-dependently reduced insoluble EPS, CFU counts, and dry weight of biofilms. The pH was maintained above 5.5 in the 6-shogaol-treated group. CLSM images showed that S. mutans proliferation, C. albicans hyphal development, and EPS production were markedly inhibited in biofilms treated with 6-shogaol. The expression of gtfB and gtfC was significantly downregulated by 6-shogaol. Conclusions: These findings suggest that 6-shogaol has the potential to be a promising natural product for the prevention and management of oral biofilm-related oral diseases. Full article