Adaptive responses of Porphyromonas gingivalis to hemin availability and temperature modulate the expression of its major virulence factors: a proteomic perspective.

Porphyromonas gingivalis is a key periodontal pathogen whose biofilm and virulence limit the effectiveness of mouthwashes such as chlorhexidine (CHX). This study evaluated the antibacterial, antibiofilm and virulence effects of an oxygen-releasing mouthwash against P. gingivalis, complemented by in silico docking and cytotoxicity testing on human oral fibroblasts. P. gingivalis ATCC 33277 was grown anaerobically. Minimum inhibitory (MIC), bactericidal (MBC) and biofilm inhibitory concentrations (MBIC) were determined by resazurin-based microdilution and crystal violet biofilm assays, with 0.12% CHX as control. Biofilm structure and viability were analysed by confocal microscopy. Quantitative PCR measured expression of 6 virulence- and biofilm-associated genes. Molecular docking of sodium perborate to protein targets used AutoDock GNINA. Fibroblast cytotoxicity (ISO 10993-5 threshold ≥70% viability) was evaluated over 30 min to 24 h. Bluem mouthwash showed concentration-dependent inhibition of P. gingivalis with minimum inhibitory (MIC), bactericidal (MBC) and biofilm inhibitory concentrations (MBIC) values of 0.78%, 1.56% and 3.12%, respectively. At 0.78%, biofilm biomass decreased to around 45% and at concentrations of ≥3.12% was reduced to ≤20%, with greater reduction than 0.12% CHX. Confocal imaging showed reduced biomass and thickness with a predominance of nonviable cells at higher concentrations. Bluem mouthwash was associated with downregulation of virulence-related genes, with fimA and hagA expression reduced at concentrations ≥0.78%, whereas 0.12% CHX increased fimA expression. Molecular docking predicted moderate binding affinities of sodium perborate with key virulence proteins, including kgp and mfa1. Bluem concentrations ≤0.78% maintained noncytotoxic fibroblast viability, while ≥1.56% and 0.12% CHX were cytotoxic across all tested periods. The oxygen-releasing mouthwash inhibited P. gingivalis biofilm formation, modulated virulence-associated gene expression and showed a wider noncytotoxic range on oral periodontal fibroblasts than chlorhexidine. These findings on an oxygen-releasing mouthwash may help guide concentration selection and inform its potential adjunctive use in periodontal protocols, but clinical outcome studies are still needed before routine use can be recommended.

Chaotropic ion-tuned protein/peptide hydrogel with enhanced trans-barrier delivery for effective periodontitis management via pathogen clearance, immunomodulation, and MSC preservation.

Bioinspired nanomicelles with octopus-like adhesion for microenvironmental reprogramming in periodontitis.

Upregulated expressions of caspase-4 and -5 upon challenging with periodontal microorganisms in human gingival epithelial cells.

Injectable Schiff base-engineered hydrogel for spatiotemporal liraglutide delivery orchestrates diabetic periodontitis regression via multimodal microenvironment reprogramming.

Evaluation of photodynamic therapy using indocyanine green loaded chitosan nanoparticles, as an adjunct to non-surgical periodontal therapy in patients with stage I and II periodontitis". A randomized controlled trial.

The potential of gypsum chips containing chlorhexidine (CHX) as an adjunctive therapy for periodontitis has not yet been explored. Therefore, the aim of this study is to develop gypsum chips containing CHX as adjunctive therapy for periodontitis.Gypsum chips were prepared with water-to-powder (w/p) ratios of 0.4, 0.5, and 0.6. The 0.4 ratio, which exhibited the highest flexural strength, was selected for CHX incorporation at 0, 10, and 20% (Gyp-CHX 0, 10, and 20%). Microstructure was analyzed using scanning electron microscopy (SEM). Setting time was measured with a Vicat needle, and flexural strength with a universal testing machine. CHX release was quantified using UV-vis spectroscopy for up to 7 days, degradation by weight loss, and antibacterial activity against Porphyromonas gingivalis by inhibition zone testing.The results suggested that the 0.4 w/p ratio showed the highest flexural strength (17.88 MPa). Incorporation of CHX reduced crystal size (8.17 µm at 10% and 4.84 µm at 20%), prolonged setting time (18.23 minutes in control vs. 61.11 and 75.95 minutes), and decreased flexural strength (6.52 and 4.30 MPa). Both Gyp-CHX 10 and 20% exhibited sustained release with an initial burst, progressive degradation over 7 days, and antibacterial activity, while no inhibition was observed in the control.CHX-loaded gypsum chips demonstrated sustained release and antibacterial activity, indicating potential as an adjunctive therapy for periodontitis despite reduced mechanical strength.

Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (P. gingivalis) are key pathogens in periodontitis. Considering the antibacterial properties of licorice, this study investigated the prevalence of Aa and P. gingivalis in patients with chronic periodontitis using PCR and evaluated the antimicrobial effects of licorice root extract. Subgingival samples were obtained from 50 patients with chronic periodontitis at the Faculty of Dentistry, Tabriz University of Medical Sciences. DNA was extracted, and specific primers were used for PCR detection. All positive isolates (n=24) were cultured, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of licorice extract (Barij Esans Co., Iran) were determined in triplicate using the microbroth dilution method. Statistical analyses were performed using one-way ANOVA and chi-square tests with SPSS 24. Aa and P. gingivalis were detected in 48% of samples (Aa: 18%, P. gingivalis: 26%, both: 4%). The MIC and MBC values of licorice extract were 7.81 ± 0.42 mg/mL and 20.53 ± 0.61 mg/mL for Aa, and 4.69 ± 0.37 mg/mL and 10.94 ± 0.54 mg/mL for P. gingivalis, respectively. Statistical analysis confirmed significant differences in bacterial prevalence between localized and generalized periodontitis (p < 0.05). Due to the potential toxicity of licorice, such as hypertension and hypokalemia, careful dose standardization and toxicity evaluation must be performed before clinical use. Licorice extract demonstrated promising in vitro antibacterial activity against Aa and P. gingivalis. These findings suggest that licorice may serve as a potential adjunctive agent in the management of chronic periodontitis. However, further in vivo and clinical studies are required before clinical application.

Periodontal disease results from dysbiotic oral biofilms and the host's inflammatory response. Given the limitations of conventional therapies, this study aimed to evaluate the efficacy and safety of Weissella cibaria CMU (OraCMU) in improving gingival inflammation in individuals with gingivitis and incipient periodontitis. In this randomized, double-blind, placebo-controlled trial, 80 participants received either OraCMU tablets (2.0 × 108 CFU/g; n = 40) or placebo (n = 40) twice daily for 8 weeks. The primary outcome was the gingival index (GI), and secondary outcomes included bleeding on probing (BOP), probing depth, clinical attachment level, gingival recession, plaque index, inflammation-related proteins, and oral microbiota. Clinical parameters were assessed at six preselected index teeth (#16, 12, 24, 32, 36, and 44). At week 8, the probiotic group showed significantly greater reductions in GI (-0.19 ± 0.03 vs. -0.08 ± 0.04; P = .035) and BOP (-7.74 ± 1.54 vs. -2.82 ± 1.60; P = .030) compared with the placebo group. Inflammatory markers, including fibroblast growth factor-5 (P = .003), thymic stromal lymphopoietin (P = .017), and the receptor activator of nuclear factor κB ligand/osteoprotegerin ratio (P = .021), were significantly decreased. The levels of Porphyromonas gingivalis (P = .001), Treponema denticola (P = .005), and Prevotella intermedia (P = .046) were also significantly reduced, while Weissella increased (P < .001) in the probiotic group. Eight-week supplementation with OraCMU improved gingival health and modulated the oral microbiota and inflammatory response. No serious adverse events were reported during the study period. These findings support the potential clinical utility of OraCMU as a probiotic adjunct for managing gingivitis.

Porphyromonas gingivalis lipids enhance RANKL-mediated osteoclast formation.

This study aimed to characterize salivary microbiome compositions that can classify periodontal health and various stages of periodontitis. We collected saliva samples from 250 study subjects, including 100 periodontally healthy controls and 150 periodontitis patients in stages I/II/III. We performed 16S ribosomal RNA gene sequencing to characterize their salivary microbiomes. Alpha diversities show significant differences between healthy and periodontitis. Differentially abundant taxa were identified by ANCOM. Random forest machine learning models were used to classify each periodontitis stage based on the centered log-ratio of differentially abundant taxa. We identified 20 differentially abundant taxa among the groups in the salivary microbiomes of all groups. Among these differentially abundant taxa, Porphyromonas gingivalis and Actinomyces spp. are the most important taxa on the random forest model to classify the periodontitis statuses. Our random forest model classified multiple periodontitis statuses with an area-under-curve of 0.829 ± 0.124, sensitivity 0.884 ± 0.022, and specificity 0.652 ± 0.065. Moreover, because it can be difficult to diagnose in dentistry practice, we performed our classifier model to distinguish healthy or stage I, providing an area-under-curve of 0.736 ± 0.168, sensitivity 0.789 ± 0.102, and specificity 0.622 ± 0.196. Furthermore, our random forest model detected periodontitis patients from healthy individuals with an area-under-curve of 0.924 ± 0.088, sensitivity of 0.862 ± 0.175, and specificity of 0.921 ± 0.061. Finally, we evaluated our classification model with external data sets from Spanish and Portuguese subjects. Some evaluations showed a slight decrease, but it might be due to different salivary microbiome compositions from ethnicity. Significant differences were identified in the differentially abundant taxa among healthy controls and the various stages of periodontitis.IMPORTANCEPeriodontitis is a common but complex oral disease that can lead to tooth loss and contribute to systemic health issues. Early and accurate diagnosis is essential for effective intervention, yet traditional diagnostic methods often rely on invasive clinical assessments that may miss early signs. This study demonstrates that salivary microbiome profiles can be used to classify both periodontal health and multiple periodontitis stages using a machine learning approach. By identifying the 20 key microbial taxa, including Actinomyces spp., we developed a non-invasive predictive model with high diagnostic accuracy. Importantly, the model was also able to detect early-stage disease and performed well across external data sets, highlighting its potential for broader clinical application. These findings suggest that a salivary microbiome-based diagnostic tool may support more precise, accessible, and early diagnosis of periodontitis in dental disease management.

Porphyromonas gingivalis produces a functional HemH ferrochelatase important for its survival in a heme-limited environment.

Berberine-loaded human dental pulp stem cells exosomes potentiate antimicrobial photodynamic therapy against Porphyromonas gingivalis biofilms.

Impact of saliva on the efficacy of antiseptics against selected periopathogens.

Periodontitis is an inflammatory condition triggered by a host response to pathogenic dental biofilms, particularly Gram-negative anaerobes such as Porphyromonas gingivalis (P gingivalis). Effective management often involves scaling, root planing, and chemical treatments. Herbal remedies, such as onion extracts, have shown potential in combating periodontal pathogens due to their low toxicity and beneficial properties. This interventional study aims to evaluate the antimicrobial, anti-inflammatory, and antioxidant properties of onion peel extract against P gingivalis in an in vitro setting. Onion peels were cleaned, dried, powdered, and extracted using the Soxhlet method. The minimum inhibitory concentration of the extract against P gingivalis was determined. Antioxidant activity was assessed using the 2,2-diphenyl-picryl-hydrazyl assay, and anti-inflammatory effects were evaluated through matrix metalloproteinase (MMP) inhibition assays. The minimum inhibitory concentration for onion peel extract was 0.2 µL/mL, indicating significant antimicrobial activity. The 2,2-diphenyl-picryl-hydrazyl assay revealed 40% antioxidant activity at concentrations ranging from 25 to 100 µL/mL. The anti-inflammatory assay demonstrated a 65% inhibition of MMP-9 and a 72% inhibition of MMP-2, suggesting robust anti-inflammatory effects. The findings suggest that onion peel extract has antibacterial, antioxidant, and anti-inflammatory qualities, implying it could be used therapeutically to treat periodontal diseases. Its effectiveness in lowering P gingivalis growth and inflammation demonstrates its potential as a natural supplement to conventional treatments.

Porphyromonas gingivalis is a key pathogen in periodontitis, with secreted proteases as major virulence factors. We developed a screening method to generate and identify P. gingivalis mutants with elevated protease activity. Mutations were induced using the mutagens 2,6-diaminopurine (2,6-DAP) or ethyl methanesulfonate (EMS), and the mutagenized cells were subsequently plated on casein agar. During colony growth, the medium became opaque due to partial casein precipitation, whereas colonies with higher protease activity produced clear halos through casein degradation. Colonies that formed halos earlier than the wild type were selected for further analysis. Liquid culture assays of the supernatants identified four strains with enhanced protease activity, of which two were 2,6-DAP-derived and two were EMS-derived. Whole-genome sequencing revealed that the two 2,6-DAP-derived strains carried mutations in iron transport-related genes (foeA and tonB, respectively), likely increasing protease levels through iron limitation-induced upregulation of rgpA. The two EMS-derived strains contained multiple mutations, including one in rgpA, a major protease gene. The N-terminal region of RgpA, which contains the protease motif, harbored the G450D mutation in one strain and the C600Y mutation in the other. These results demonstrate that our method efficiently generates P. gingivalis mutants with protease gene alterations that increase enzymatic activity. This approach provides a useful tool for studying protease function and virulence mechanisms in this pathogen, and for identifying genes that affect protease secretion.

Odor characteristics and associated bacterial profiles in peri-implantitis using a novel odor measurement device.

Hidden oral-joint-lung axis: Porphyromonas gingivalis Infection promotes the EMyT of RA-ILD by inhibiting the JUN-regulated palmitoylation balance.

Periodontitis is a chronic inflammatory disease primarily driven by pathogenic biofilms, and affects more than 90% of the global population. The increasing prevalence of bacterial resistance, coupled with the protective nature of resilient biofilms, makes it challenging to achieve satisfactory therapeutic outcomes. In this study, an organic small molecule-based photothermal reagent (FNP) with excellent photothermal property is designed by rational tailor of donor-acceptor combinations, and a supramolecular nucleoside hydrogel (ZBAg) is developed via silver ion-stabilized base pairing and dynamic boronate ester bonds. The ZBAg hydrogel exhibits a unique coordination mechanism distinct from the traditional intermolecular i-motif coordination mode. The ZBAg@FNP hydrogel is prepared by encapsulating FNP within ZBAg hydrogel, which demonstrates excellent biocompatibility and achieves controlled Ag+ release triggered by localized hyperthermia. The ZBAg@FNP hydrogel can damage biofilm structure through photothermal therapy and then improves the penetration of Ag+ into the biofilms, resulting in synergistic eradication of the biofilms of oral pathogenic bacteria (Porphyromonas gingivalis and Streptococcus mutans). ZBAg@FNP hydrogel treatment significantly reduces the levels of proinflammatory cytokines, increases the levels of anti-inflammatory cytokines, and reduces alveolar resorption in periodontitis of rats. This study provides a new strategy for treating periodontitis, and offers insights into the design of antibiofilm materials.