Subgingival Plaque Research Articles

Distribution and clinical characterization of pathogenic bacteria in combined periodontal and endodontic lesions of periodontal origin by digital technology

Abstract In this paper, the Logistic regression model and χ2 automatic interaction test were used to study the distribution, number, and correlation of common pathogenic bacteria of periodontal origin with combined periodontal and endodontic lesions by sample training, extracting variable characteristics, and then these variables were modeled as characteristic variables of the regression model to test whether the independent variables were significantly correlated with the dependent variables. It is also necessary to perform χ2 automatic interaction test to compare with the normal distribution, and the results are merged into one group if they are the same and not incorporated into one group if they are different. After the merging was completed, the splitting was done. The study group had a detection rate of pathogenic bacteria of 50.70%, while the control group had a detection rate of 12.24%, according to the results. Campylobacter spp. was the main bacteria that infected periodontal pockets in the study group. And Clostridium spp. The root canal specimens were mainly from Corynebacterium spp. and Actinobacillus spp. There was a significant difference between the pathogenic species and the control group P<0.05. Campylobacter spp. was also a risk factor for co-morbidities (P=0.031). Intra-root canal tissue with its subgingival plaque pathogenic bacteria Ef, Pe (Ρ<0.05), Pg, Td, Tf (Ρ<0.01) played a more important role in the development of pulpitis. Before and after clinical treatment, Pgi showed the most significant decrease in bacterial counts (t=2.759, P=0.022).

Establishing the Essential Zone: Free Gingival Graft for Gingival Augmentation and Root Coverage

Gingival recession is a frequently encountered clinical finding which causes compromised aesthetics and dentinal hypersensitivity leading to an inadequate zone of keratinized gingiva and might facilitate subgingival plaque formation resulting in further attachment loss. Epithelized soft tissue graft harvested from the hard palate, commonly known as free gingival graft is simple and highly predictable when used to increase the amount of keratinized tissue. This case report highlights the use of free gingival graft as a gingival augmentation and root coverage procedure for 26-year-old patients with Cairo RT2 mucogingival defects with optimum aesthetic outcome. ­­

Demonstration of Urease Activity in Subgingival Plaque Sample of Periodontitis Patients in a Tertiary Care Center of Nepal

Demonstration of Urease Activity in Subgingival Plaque Sample of Periodontitis Patients in a Tertiary Care Center of Nepal

Methotrexate and Non-Surgical Periodontal Treatment Change the Oral-Gut Microbiota in Rheumatoid Arthritis: A Prospective Cohort Study.

This study evaluated the changes in the composition of oral-gut microbiota in patients with rheumatoid arthritis (RA) caused by methotrexate (MTX) and non-surgical periodontal treatment (NSPT). Assessments were performed at baseline (T0), 6 months after MTX treatment (T1), and 45 days after NSPT (T2). The composition of the oral and gut microbiota was assessed by amplifying the V4 region of the 16S gene from subgingival plaques and stools. The results of the analysis of continuous variables were presented descriptively and non-parametric tests and Spearman's correlation were adopted. A total of 37 patients (27 with periodontitis) were evaluated at T0; 32 patients (24 with periodontitis) at T1; and 28 patients (17 with periodontitis) at T2. MTX tended to reduce the alpha diversity of the oral-gut microbiota, while NSPT appeared to increase the number of different species of oral microbiota. MTX and NSPT influenced beta diversity in the oral microbiota. The relative abundance of oral microbiota was directly influenced by periodontal status. MTX did not affect the periodontal condition but modified the correlations that varied from weak to moderate (p < 0.05) between clinical parameters and the microbiota. MTX and NSPT directly affected the composition and richness of the oral-gut microbiota. However, MTX did not influence periodontal parameters.

Perception of Oral Health-related Quality of Life Before the First Step and After the Second Step of Periodontal Therapy

Background: Periodontal research has focused on clinical outcomes of periodontitis and in a lesser extent on patient-reported outcomes. Objective: The objectives of this study were to 1) determine oral health-related quality of life (OHRQoL) before the first step and after the second step of periodontitis therapy and 2) compare sociodemographic and clinical characteristics with changes in OHRQoL. Methods: Patients with periodontitis that had never been treated with subgingival plaque instrumentation were recruited. Clinical parameters were recorded. A questionnaire was applied to collect sociodemographic data, smoking status, and pain. The Oral Health Impact Profile-14 (OHIP-14) was used to evaluate OHRQoL before the first step and after the second step of periodontitis therapy. Results: Fifty-one participants completed the study, mean age 46.88 years ± 11.16. OHIP-14 total score decreased from 16.98 ± 11.48 to 8.41 ± 9.06 after treatment. Improvements in physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap accounted for the changes. The most frequent periodontal staging was stage III. As for grading, Grade A was diagnosed in 16 (31.37 %) participants, Grade B in 16 (31.37 %), and Grade C in 17 (33.33 %). Mean plaque index was 61.4 % ± 17.6 before the first step of periodontitis therapy and 22.8 % ± 10.6 after. Pain in the last month decreased after periodontal care. No differences in OHRQoL changes were detected when comparing age categories, gender, and educational level. Better scores were reported from non-smokers, before and after therapy (p = 0.003). Conclusion: Periodontal therapy had a positive impact on self-perceived quality of life of patients.

Alterations of oral and gut viromes in hypertension and/or periodontitis.

The microbiota plays an important role in both hypertension (HTN) and periodontitis (PD), and PD exacerbates the development of HTN by oral and gut microbiota. Previous studies have focused on exploring the importance of the bacteriome in HTN and PD but overlooked the impact of the virome, which is also a member of the microbiota. We collected 180 samples of subgingival plaques, saliva, and feces from a cohort of healthy subjects (nHTNnPD), subjects with HTN (HTNnPD) or PD (PDnHTN), and subjects with both HTN and PD (HTNPD). We performed metagenomic sequencing to assess the roles of the oral and gut viromes in HTN and PD. The HTNnPD, PDnHTN, and HTNPD groups all showed significantly distinct beta diversity from the nHTNnPD group in saliva. We analyzed alterations in oral and gut viral composition in HTN and/or PD and identified significantly changed viruses in each group. Many viruses across three sites were significantly associated with blood pressure and other clinical parameters. Combined with these clinical associations, we found that Gillianvirus in subgingival plaques was negatively associated with HTN and that Torbevirus in saliva was positively associated with HTN. We found that Pepyhexavirus from subgingival plaques was indicated to be transferred to the gut. We finally evaluated viral-bacterial transkingdom interactions and found that viruses and bacteria may cooperate to affect HTN and PD. Correspondingly, HTN and PD may synergize to improve communications between viruses and bacteria.IMPORTANCEPeriodontitis (PD) and hypertension (HTN) are both highly prevalent worldwide and cause serious adverse outcomes. Increasing studies have shown that PD exacerbates HTN by oral and gut microbiota. Previous studies have focused on exploring the importance of the bacteriome in HTN and PD but overlooked the impact of the virome, even though viruses are common inhabitants in humans. Alterations in oral and gut viral diversity and composition contribute to diseases. The present study, for the first time, profiled the oral and gut viromes in HTN and/or PD. We identified key indicator viruses and their clinical implications in HTN and/or PD. We also investigated interactions between viruses and bacteria. This work improved the overall understanding of the viromes in HTN and PD, providing vital insights into the role of the virome in the development of HTN and PD.

Toward Elimination of Electrochemical Corrosion in Dental Implants: A Zirconia-Titanium Composite Prototype.

Background Titanium dental implants (e.g., Nobel Biocare, Switzerland) are routinely used as support for dental restoration. Titanium has been the material of choice due to its corrosion resistance and ability to integrate with bone. Nevertheless, corrosion and titanium dissolution do occur. Compared to control, peri-implantitis tissue biopsies have been shown to contain high concentrations of dissolved titanium as well as metal particles. Dissolved titanium species have been found to be associated with the structure/diversity of the subgingival plaque microbiome and the extent of global methylation. Of note, peri-implantitis and peri-implant mucositis are common biological complications of implant therapy. Microorganisms and local inflammation together with a gradient of oxygen have been proven to form an electrochemical fuel cell, which generates the current that flows through the body of the titanium implant. Effectively, the fuel cell reduces oxygen and oxidizes titanium that turns into a soluble form. We are proposing a new zirconia-titanium composite implant design whereby the electrical current is disrupted while other properties are still conducive to osseointegration. Methodology Biocompatible zirconia bolts were treated with hydrofluoric acid (HF) and coated with titanium in a vacuum evaporator.The coating was masked with nail polish, and unmasked areas were etched with HF followed by mask removal with a solvent.Microbial challenges were conducted with a volunteer's plaque.Regular implant (control) and the prototype were inserted into simulated peri-implant environments implemented as a fiberglass sleeve immersed into a growth medium.After a five-day growth, samples were taken and HNO3 digested. Dissolved titanium was evaluated by inductively coupled plasma mass spectrometry. Results Proof-of-concept implant prototypes were successfully created.Vacuum deposition results in reproducible stable titanium coating. The thickness of the titanium coating was estimated using atomic force microscopy.A microbial challenge revealed that compared to the commercial titanium implant, the new implant prototype showed decreased amounts of corrosion-leached titanium. Conclusions We demonstrate a path forward toward a new design of a dental implant, whereby corrosion-induced electrical currents are interrupted resulting in a decreased amount of dissolved titanium.

Subgingival Plaque as a Potential Reservoir for SARS-CoV-2 Virus in Patients Recovered from COVID-19 Infection: A Cross-sectional Study

Background Subgingival plaque biofilm is a potential harboring site for bacteria and viruses, serving as a source of entry into the bloodstream. The presence of Severe Acute Respiratory Syndrome Coronavirus 2 RNA (SARS-CoV-2 RNA) in subgingival plaque could be a possible source for cross infection due to aerosol contamination during dental procedures. Objectives The objective of this study was to investigate the presence of SARS-CoV-2 RNA in the subgingival plaque biofilm of patients who recovered from COVID-19 infection. Materials and Methods Ten subjects visiting the Outpatient clinic with a previous history of COVID-19 infection were recruited for this cross-sectional study. Subgingival plaque sample was collected from all four quadrants using a sterile curette. Nasopharyngeal and oropharyngeal swabs were taken from all the subjects. Reverse transcriptase real-time qualitative polymerase chain reaction (RT-PCR) was used to determine the presence of SARS-CoV-2 RNA using BAG SARS-CoV-2 RT-PCR kit targeting E gene, RdRp gene, and internal control. Results Ten participants (seven females and three males) with a previous history of COVID-19 infection were included in the study. Six participants previously presented with mild COVID-19 infection (uncomplicated upper respiratory tract infection, mild fever, cough, sore throat, nasal congestion, malaise, headache, without evidence of breathlessness or hypoxia), and four participants previously presented with moderate COVID-19 infection (dyspnea and or hypoxia, fever, cough, SpO2 90%–94% on room air, respiratory rate more or equal to 24 per minute) according to clinical management protocol for COVID-19, Government of India. The nasopharyngeal, oropharyngeal, and subgingival plaque samples tested negative for SARS-CoV-2 RNA. Conclusion The absence of the SARS-CoV-2 virus in the subgingival plaque sample of patients recovered from COVID-19 infection suggests that dental plaque could not be a potential reservoir of the virus. However, clinicians should take at most precautions while treating the patients recovered from COVID-19 infection and should anticipate a change in subgingival environment leading to alteration in periodontal disease progression.

In Vitro Eradication of Planktonic, Saliva and Biofilm Bacteria Using Lingonberry Extract as a Photosensitizer for Visible Light Plus Water-Filtered Infrared-A Irradiation

Antimicrobial photodynamic treatment (aPDT) with visible light plus water-filtered infrared-A irradiation (VIS-wIRA) and natural single- or multi-component photosensitizers (PSs) was shown to have potent antimicrobial activity. The aim of this study was to obtain information on the antimicrobial effects of aPDT-VIS-wIRA with lingonberry extract (LE) against bacteria that play a role in oral health. Planktonic bacterial cultures of the Gram-positive E. faecalis T9, S. mutans DSM20523, S. oralis ATCC 35037 and S. sobrinus PSM 203513, the Gram-negative N. oralis 14F2 FG-15-7B, F. nucleatum ATCC 25586, and V. parvula DSM, the anaerobic F. nucleatum ATCC 25586 and V. parvula DSM 2008, and the total mixed bacteria from pooled saliva and supra- and subgingival plaques of volunteers were all treated and compared. aPDT-VIS-wIRA with LE as PS significantly (p &lt; 0.008) reduced the growth of all tested Gram-positive, Gram-negative, as well as aerobic and anaerobic bacterial strains, whereas without irradiation no reductions were seen (p &lt; 0.0001). NaCl, with or without irradiation, was ineffective. After treatment with CHX 0.2%, the highest killing rate (100%) was observed, and no bacteria (0 log10 CFU) were cultivable. The method also significantly reduced all of the bacteria present in saliva and in the gingival biofilms. Three-dimensional visualization of viable and non-viable microorganisms revealed that LE penetrated deeper into the cell wall layers than CHX 0.2%. LE was an appropriate PS for eradicating microorganisms with VIS-wIRA, either in their planktonic form or in saliva and gingival plaque biofilms. These results encourage further investigation in order to determine which LE compounds contribute to the photosensitizing effect and to evaluate the size of the effect on maintaining oral health.

Proteome and immune responses of extracellular vesicles derived from macrophages infected with the periodontal pathogen Tannerella forsythia.

Periodontitis is a chronic inflammatory disease caused by periodontal pathogens in subgingival plaque and is associated with systemic inflammatory diseases. Extracellular vesicles (EVs) released from host cells and pathogens carry a variety of biological molecules and are of interest for their role in disease progression and as diagnostic markers. In the present study, we analysed the proteome and inflammatory response of EVs derived from macrophages infected with Tannerella forsythia, a periodontal pathogen. The EVs isolated from the cell conditioned medium of T. forsythia-infected macrophages were divided into two distinct vesicles, macrophage-derived EVs and T. forsythia-derived OMVs, by size exclusion chromatography combined with density gradient ultracentrifugation. Proteome analysis showed that in T. forsythia infection, macrophage-derived EVs were enriched with pro-inflammatory cytokines and inflammatory mediators associated with periodontitis progression. T. forsythia-derived OMVs harboured several known virulence factors, including BspA, sialidase, GroEL and various bacterial lipoproteins. T. forsythia-derived OMVs induced pro-inflammatory responses via TLR2 activation. In addition, we demonstrated that T. forsythia actively released OMVs when T. forsythia encountered macrophage-derived soluble molecules. Taken together, our results provide insight into the characterisation of EVs derived from cells infected with a periodontal pathogen.

Oral pathogens exacerbate Parkinson’s disease by promoting Th1 cell infiltration in mice

BackgroundParkinson’s disease (PD) is a common chronic neurological disorder with a high risk of disability and no cure. Periodontitis is an infectious bacterial disease occurring in periodontal supporting tissues. Studies have shown that periodontitis is closely related to PD. However, direct evidence of the effect of periodontitis on PD is lacking. Here, we demonstrated that ligature-induced periodontitis with application of subgingival plaque (LIP-SP) exacerbated motor dysfunction, microglial activation, and dopaminergic neuron loss in 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice.ResultsThe 16S rRNA gene sequencing revealed that LIP-SP induced oral and gut dysbiosis. Particularly, Veillonella parvula (V. parvula) and Streptococcus mutans (S. mutans) from oral ligatures were increased in the fecal samples of MPTP + LIP-SP treated mice. We further demonstrated that V. parvula and S. mutans played crucial roles in LIP-SP mediated exacerbation of motor dysfunction and neurodegeneration in PD mice. V. parvula and S. mutans caused microglial activation in the brain, as well as T helper 1 (Th1) cells infiltration in the brain, cervical lymph nodes, ileum and colon in PD mice. Moreover, we observed a protective effect of IFNγ neutralization on dopaminergic neurons in V. parvula- and S. mutans-treated PD mice.ConclusionsOur study demonstrates that oral pathogens V. parvula and S. mutans necessitate the existence of periodontitis to exacerbate motor dysfunction and neurodegeneration in MPTP-induced PD mice. The underlying mechanisms include alterations of oral and gut microbiota, along with immune activation in both brain and peripheral regions.863jmMzLiThtjrDnNG72wqVideo

Bacteriome analysis of Aggregatibacter actinomycetemcomitans-JP2 genotype-associated Grade C periodontitis in Moroccan adolescents.

Grade C (previously aggressive) periodontitis (GCP) in adolescents is prevalent in certain parts of Africa where it is associated with JP2 genotype, a highly virulent strain of Aggregatibacter actinomycetemcomitans. The aim of this study was to characterize the subgingival bacteriome in Moroccan subjects with GCP positive to A. actinomycetemcomitans JP2 genotype. Subgingival plaque samples were collected from shallow and deep pockets of 8 subjects with GCP (17.2 ± 1.5 years) and from gingival sulci of 13 controls with no periodontitis (14.6 ± 1.1 years). Identification and genotyping of A. actinomycetemcomitans was performed using PCR analysis of the ltx operon, while bacteriome profiling was done by 16S rRNA gene sequencing (V1-V3 region). Groups were compared in terms of microbial diversity, abundances, and dysbiosis. The shallow and deep pocket sites from GCP cases had a significantly altered microbial composition compared to controls. Species associated with health included Haemophilus parainfluenzae, Lautropia mirabilis, Streptococcus spp., Gemella spp., and Rothia spp. While known periodontal pathogens, including Porphyromonas gingivalis, Tannerella forsythia, Treponema spp. and Fretibacterium spp., were significantly enriched in GCP, non-conventional taxa, including Pseudomonas oral taxon C61 and Enterobacter cloacae were more abundant and showed stronger association with the disease. Less significant differences in abundances of individual taxa were observed between shallow and deep pockets. Overall dysbiosis measured in terms of Subgingival Microbial Dysbiosis Index (SMDI) differentiated between GCP and no-periodontitis with 95% accuracy. The results suggest that several periodontal pathogens involved in the adult-type periodontitis also play a role in JP2 genotype-associated GCP. The potential role of non-conventional taxa in the pathogenesis of GCP warrants further investigation.

Antimicrobial peptides in treatment of Stage III Grade B periodontitis: A randomized clinical trial.

To evaluate the effects of antimicrobial peptides (AMPs) on Stage III Grade B periodontitis. This trial abided by the principle of consistency test, approved by ethics committee and registered in clinical trials. All qualified 51 patients with Stage III Grade B periodontitis were randomly divided into three groups: SRP group, SRP with minocycline hydrochloride (Mino group) as Control groups, and SRP with AMPs (AMP group) as the Test group. Clinical examinations and subgingival plaques were monitored at baseline and at 7 and 90 days after treatment in the SRP, SRP with AMP and Mino groups. The AMP group (Test group) had a reduced PD (Periodontal probing depth) and an attachment gain significantly higher than SRP and Mino groups (Control groups) at day 90. The abundance of periodontal pathogens was decreased in the AMP group at 7 and 90 days compared with the SRP group and Mino group. Only the AMP group showed an increase the abundance of periodontal probiotics including Capnocytophaga, Gemella, and Lactobacillus at 7 and 90 days. This study shows that AMPs as an adjunct to SRP promote additional clinical and microbiological benefits in the treatment of Stage III Grade B periodontitis.

Subgingival Use of Air-Polishing Powders: Status of Knowledge: A Systematic Review.

Effective subgingival biofilm removal is crucial for achieving positive and stable outcomes in periodontal therapy, forming an indispensable part of any periodontal treatment approach. The development of air-polishing tools has emerged as a promising alternative to hand and ultrasonic scalers for dental biofilm removal. The objective of this systematic review was to assess existing literature regarding the subgingival use of various types of air-polishing powders, as an effective method of subgingival biofilm control. For this, 55 articles on this subjected were sourced from searched databases and subjected to an evaluation process of their contained information, which was subsequently structured and compiled into this manuscript. The existing literature acknowledges that good subgingival biofilm control is essential for the success of periodontal therapy, including through subgingival air-polishing, as an adjunctive procedure. This approach has the potential to enhance patient comfort during and after subgingival mechanical plaque removal, thereby mitigating damage to periodontal structures. Consequently, it may lead to improved healing capabilities within the periodontal tissues and the formation of a more stable reparative gingival junctional epithelium.

Oral microbiota in periodontitis patients with and without type 2 diabetes mellitus and their shifts after the nonsurgical periodontal therapy

ObjectiveTo investigate the shift in the oral microbiota of periodontitis patients with and without type 2 diabetes mellitus (T2DM) undergoing nonsurgical periodontal treatment and its implications. MethodsEleven patients with chronic periodontitis and eleven patients with chronic periodontitis and diabetes from the Second Affiliated Hospital of Chongqing Medical University received nonsurgical periodontitis treatment and were re-evaluated 3 months later. DNA from the saliva and subgingival plaques was amplified and sequenced using 16S ribosomal RNA (16S rRNA) gene sequencing for microbiome profiling. Clinical indexes at the onset and after periodontal therapy were recorded and compared. ResultsThe species richness and dominant microbiota of periodontitis patients with and without T2DM changed significantly after nonsurgical periodontal treatment in both saliva and subgingival plaques. The periodontal condition of the patients was also effectively improved three months after therapy. Glycemic control in patients with periodontitis and T2DM was improved. Additionally, nonsurgical periodontal therapy could increase in subgingival microbial diversity and the proportion of health-associated bacteria but a proportional reduction in pathogenic bacteria in periodontitis patients with T2DM. Network analysis revealed fewer links and a lower level of centralization in the chronic periodontitis (CP) group after treatment. However, more links and a higher network density of the networks were found in the CP + T2DM group, suggesting a more stable microbial community after treatment. ConclusionsThere were significant differences in both the structural composition and reaction of the oral microbiota to periodontal treatment between periodontitis patients with and without T2DM. Nonsurgical periodontal treatment can improve metabolic control, decrease the proportion of periodontal pathogens in oral conditions, and help stabilize microbial communities in patients with periodontitis and T2DM. Furthermore, nonsurgical periodontal treatment may be a potential supplementary approach for managing T2DM.

Suppression of subgingival bacteria by antimicrobial photodynamic therapy using transgingival irradiation: A randomized clinical trial.

Antimicrobial photodynamic therapy (aPDT) is an effective method for eradicating bacteria in periodontal therapy. Standard aPDT requires the insertion of a laser tip into a periodontal pocket, in which the direction of irradiation is limited. Therefore, we devised an aPDT method that uses a transgingival near-infrared wavelength and indocyanine green-encapsulated and chitosan-coated nanoparticles as a photosensitizer. Forty patients undergoing supportive periodontal therapy, who had a single root tooth with a pocket of 5mm or deeper, were used as subjects. In the test group, aPDT was performed by laser irradiation from outside the gingiva using photosensitizer nanoparticles. In the control group, pseudo aPDT without photosensitizer was performed by transgingival irradiation. Subgingival plaque was sampled from inside the pocket before, immediately after, and 1 week after treatment, and evaluated by colony counting and real-time polymerase chain reaction. There were no significant differences in age, sex, periodontal pocket depth, and bleeding on probing between the test and control groups. Compared with the colony count before treatment, the count in the test group was significantly reduced immediately after treatment. The number of patients with colony reduction to ≤50% and ≤10% was significantly higher in the test group than in the control group. None of the participants reported pain, although one participant reported discomfort. As a bacterial control method for residual pockets in patients undergoing supportive periodontal therapy, transgingival aPDT is a promising treatment strategy that is not generally accompanied by pain or discomfort.

Alcohol Consumption and the Diversity of the Oral Microbiome in Postmenopausal Women

BackgroundAlcohol reduces neutrophil function and decreases salivary flow, which could affect the composition of the oral microbiome. ObjectiveWe hypothesized that the α- and β-diversity of the oral microbiome and the relative abundance of bacterial taxa would differ by frequency and type of alcohol consumption. MethodsWe used a food frequency questionnaire to assess the frequency of consumption of beer, wine, and liquor (drinks/week) in a sample of 1179 postmenopausal women in the Osteoporosis and Periodontal Disease Study. Women were categorized as nondrinkers, drinking <1 drink/wk, ≥1 to <7 drinks/wk, or ≥7 drinks/wk for total alcohol consumption and for beer, wine, and liquor consumption. The composition and diversity of the oral microbiome was assessed from subgingival plaque samples using 16S ribosomal RNA amplicon sequencing. Permutational multivariate analysis of variance (PERMANOVA) was used to examine β-diversity (between-sample diversity) in the microbiome between alcohol consumption categories. Analysis of covariance was used to examine the mean α-diversity (within-sample diversity), assessed by the Shannon index (species evenness), Chao1 index (species richness), and observed operational taxonomic unit (OTU) count and the mean relative abundance of 245 bacterial taxa across alcohol consumption categories. ResultsOver half of the participants (67%) consumed alcohol, with 14% reporting ≥1 drink/d. The β-diversity across categories of total alcohol consumption, but not categories of alcohol type, was statistically significantly different (P for PERMANOVA = 0.016). Mean α-diversity measures were statistically significantly higher (P < 0.05) in the highest category of total alcohol and wine consumption compared to nondrinkers; no significant associations were found for beer or liquor consumption. The relative abundance of 1 OTU, Selenomonassp._oral_taxon_133, was significantly lower in the highest level of total alcohol consumption compared to nondrinkers after adjustment for multiple comparisons. ConclusionsAlcohol consumption was associated with the diversity and composition of the subgingival microbiome.

A distinctive subgingival microbiome in patients with periodontitis and Alzheimer's disease compared with cognitively unimpaired periodontitis patients.

Periodontitis is caused by dysbiosis of oral microbes and is associated with increased cognitive decline in Alzheimer's disease (AD), and recently, a potential functional link was proposed between oral microbes and AD. We compared the oral microbiomes of patients with or without AD to evaluate the association between oral microbes and AD in periodontitis. Periodontitis patients with AD (n = 15) and cognitively unimpaired periodontitis patients (CU) (n = 14) were recruited for this study. Each patient underwent an oral examination and neuropsychological evaluation. Buccal, supragingival and subgingival plaque samples were collected, and microbiomes were analysed by next-generation sequencing. Alpha diversity, beta diversity, linear discriminant analysis effect size, analysis of variance-like differential expression analysis and network analysis were used to compare group oral microbiomes. All 29 participants had moderate to severe periodontitis. Group buccal and supragingival samples were indistinguishable, but subgingival samples demonstrated significant alpha and beta diversity differences. Differential analysis showed subgingival samples of the AD group had higher prevalence of Atopobium rimae, Dialister pneumosintes, Olsenella sp. HMT 807, Saccharibacteria (TM7) sp. HMT 348 and several species of Prevotella than the CU group. Furthermore, subgingival microbiome network analysis revealed a distinct, closely connected network in the AD group comprised of various Prevotella spp. and several anaerobic bacteria. A unique microbial composition was discovered in the subgingival region in the AD group. Specifically, potential periodontal pathogens were found to be more prevalent in the subgingival plaque samples of the AD group. These bacteria may possess a potential to worsen periodontitis and other systemic diseases. We recommend that AD patients receive regular, careful dental check-ups to ensure proper oral hygiene management.

Oral microbiota study of the patients after hospitalisation for COVID-19, considering selected dental indices and antibiotic therapy using the next generation sequencing method (NGS)

ABSTRACT Background Poor oral hygiene and the increased incidence and severity of periodontitis may exacerbate SARS-CoV-2 infection. The aim was to evaluate the oral microbiota of 60 participants divided into groups: COVID-19 convalescents who received antibiotics during hospitalization (I), COVID-19 convalescents without antibiotic therapy (II) and healthy individuals (III). Materials and Methods Dental examination was conducted, and oral health status was evaluated using selected dental indexes. Clinical samples (saliva, dorsal swabs, supragingival and subgingival plaque) were collected and used for metagenomic library to the next-generation sequencing (NGS) preparation. Results Each of the clinical materials in particular groups of patients showed a statistically significant and quantitatively different bacterial composition. Patients from group I showed significantly worse oral health, reflected by higher average values of dental indexes and also a higher percentage of Veillonella, Tannerella, Capnocytophaga and Selenomonas genera in comparison to other groups. Additionally, a statistically significant decrease in the amount of Akkermansia type in both groups with COVID-19 was observed for all materials. Conclusions The primary factor affecting the composition of oral microbiota was not the SARS-CoV-2 infection itself, but the use of antibiotic therapy. The increased percentage of pro-inflammatory pathogens observed in COVID-19 patients underscores the importance of preventing periodontal disease and improving oral hygiene in the future.

Factorial design of in situ gelling two-compartment systems containing chlorhexidine for the treatment of periodontitis

Periodontitis is one of the most widespread bacterial infectious oral diseases that affects a significant percentage of the population worldwide. Different bacterial strains are responsible for the chronic inflammation and subgingival plaque that could be effectively treated with prolonged exposure to therapeutic levels of antibiotics and antiseptics in the periodontal pockets. Medicated in situ gels of chlorhexidine (CHX), for extended drug release and long-lasting antiseptic effect in the targeted cavities, were prepared in a two-compartment system. One compartment was loaded with sodium alginate solution while other was filled with CHX and calcium solution. The mixing of the solutions during the application resulted in gelation. Two 33 full factorial designs were applied in this study in order to optimize the gel formulation. Initially, the effects of concentration of gelling agent, crosslinker, and pH of the system on the dependent variables such as gel formation and structure characteristics were investigated. Then, the concentration of the crosslinker was optimized. Afterwards, the effect of gelling agent, loading of the drug, and pH of the gel system were correlated with the gel characteristics through another factorial design. Optimized formulations were tested for mucoadhesion, in vitro drug release, and microbiological investigation. Based on the results of the factorial design, mucoadhesiveness, antimicrobial investigation, and drug release, a 4 % alginate composition can be considered optimal. Overall, the optimized in situ periodontal gel was found to be effective with prolonged retention time and desirable outcomes.