Subgingival Plaque Samples Research Articles

Clinical and Microbiological Periodontal Biofilm Evaluation of Patients with Type I Diabetes

Background/Objectives: The purpose of this study was to assess the microbial composition and density of subgingival plaque samples for periodontal pathogens while correlating the values with glycemic control levels via glycated hemoglobin (HbA1c), a type of hemoglobin that has chemically linked glucose, in type I diabetes individuals who will undergo complex oral rehabilitation through orthodontic treatment and implant surgery. Methods: A cohort of 42 adults with type I diabetes were included in this study. The subjects sustained a comprehensive periodontal clinical examination as well as microbiological assessments of their subgingival plaque samples through quantitative real-time PCR. The samples were collected from the two deepest pockets of each subject. Results: The highest number of periodontopathogenic bacteria was observed in the pockets of 5–7 mm. T. forsythia showed the highest prevalence (20.48%), with decreasing numbers as follows: T. denticola (13.31%), P. gingivalis (11.26%), A. actinomycetemcomitans (7%), and P. intermedia (4.9%). T. denticola and T. forsythia were significantly more commonly observed in individuals with elevated HbA1c serum levels. No correlation was observed between P. gingivalis, A. actinomycetemcomitans, P. intermedia presence, and the HbA1c value. Conclusions: Periodontopathogenic agents’ presence in subgingival biofilm samples varied in accordance with the pocket probing depth and metabolic control of the diabetic individuals. In our study, the appearance of these periodontopathogenic agents was linked to lowered metabolic control in patients with type I diabetes mellitus.

Association Between Dietary Patterns and Subgingival Microbiota: Results From the Oral Infections, Glucose Intolerance, and Insulin Resistance Study (ORIGINS).

To study the association between dietary patterns and subgingival microbiota. Participants (n = 651) who were enrolled in the Oral Infections, Glucose Intolerance, and Insulin Resistance Study (ORIGINS) with subgingival plaque sampling (n = 890 plaques) and a dietary assessment were included. 16S rRNA gene amplicon sequences of subgingival plaque from sites with either probing depth <4 or ≥4 mm were processed separately and used to obtain α-diversity metrics (Faith, Shannon, Simpson, Observed) and taxa ratios (Red Complex to Corynebacterium [RCLR], Treponema to Corynebacterium [TCLR], and Treponema to Neisseria [TNLR]). Food frequency questionnaires (FFQs) were processed to calculate Alternate Healthy Eating Index (AHEI) and A Priori Diet Quality Score (APDQS) scores. Mixed regression models examined the mean levels of microbial metrics across quartiles of diet quality. Means ± standard errors are reported along with p-values. In multivariable models assessing the association between diet scores and α-diversity metrics, higher AHEI values were significantly associated with lower Faith (p-value = 0.01) and Observed (p-value = 0.04) diversity values; similar findings were observed for APDQS (p-value = 0.01, p-value = 0.04). In multivariable models assessing the association between diet scores (AHEI and APDQS) and taxa ratios (RCLR, TCLR and TNLR), as the AHEI quartile increased, all taxa ratios decreased significantly as follows: -1.06 ± 0.093 in Q1 to -1.34 ± 0.099 in Q4 (RCLR), -0.43 ± 0.077 in Q1 to -0.64 ± 0.083 in Q4 (TCLR) and -0.09 ± 0.083 in Q1 to -0.38 ± 0.089 in Q4 (TNLR), respectively. In contrast, as the APDQS quartiles increased, only TNLR decreased significantly from -0.08 ± 0.085 in Q1 to -0.34 ± 0.091 in Q4. Diets rich in fruits, vegetables, whole grains and other nutritionally rich plant foods are associated with lower oral microbial diversity and favourable ratios of pathogenic to commensal microbiota.

Multi-site analysis of biosynthetic gene clusters from the periodontitis oral microbiome.

Background. Bacteria significantly influence human health and disease, with bacterial biosynthetic gene clusters (BGCs) being crucial in the microbiome-host and microbe-microbe interactions.Gap statement. Despite extensive research into BGCs within the human gut microbiome, their roles in the oral microbiome are less understood.Aim. This pilot study utilizes high-throughput shotgun metagenomic sequencing to examine the oral microbiota in different niches, particularly focusing on the association of BGCs with periodontitis.Methodology. We analysed saliva, subgingival plaque and supragingival plaque samples from periodontitis patients (n=23) and controls (n=16). DNA was extracted from these samples using standardized protocols. The high-throughput shotgun metagenomic sequencing was then performed to obtain comprehensive genetic information from the microbial communities present in the samples.Results. Our study identified 10 742 BGCs, with certain clusters being niche-specific. Notably, aryl polyenes and bacteriocins were the most prevalent BGCs identified. We discovered several 'novel' BGCs that are widely represented across various bacterial phyla and identified BGCs that had different distributions between periodontitis and control subjects. Our systematic approach unveiled the previously unexplored biosynthetic pathways that may be key players in periodontitis.Conclusions. Our research expands the current metagenomic knowledge of the oral microbiota in both healthy and periodontally diseased states. These findings highlight the presence of novel biosynthetic pathways in the oral cavity and suggest a complex network of host-microbe and microbe-microbe interactions, potentially influencing periodontal disease. The BGCs identified in this study pave the way for future investigations into the role of small-molecule-mediated interactions within the human oral microbiota and their impact on periodontitis.

Assessment of the Efficacy of Indigenously Prepared Azadirachta Indica Mouthwash on P. Gingivalis in Chronic Periodontitis Patients: A Microbiological Study

Aim: The present study aimed to compare and evaluate the antimicrobial effect of Azadirachta Indica (Neem mouthwash) to chlorhexidine mouthwash on P. gingivalis. Materials ans Methods: The subjects were divided into 2 groups. Group I included 5 subjects who used self-prepared neem mouthwash, and Group II included 5 subjects who used 0.2% chlorhexidine mouthwash. Subgingival plaque samples were taken at baseline and the 15th day after using the mouthwash and subjected to microbiological evaluation. Results: The colony forming unit (CFU) of P. gingivalis was calculated at baseline and on the 15th day after using mouthwash using the digit colony counter. A comparison of the total CFU of both mouthwashes revealed that the neem mouth was effective in reducing the microbial colonies of P. gingivalis from baseline to the 15th day. Conclusion: It was concluded that the self-prepared neem mouthwash was effective in reducing the colony-forming unit of P. gingivalis in the sub-gingival plaque samples and showed better results than the commercially available chemical-based chlorhexidine mouthwash.

Effectiveness of 0.2% Hyaluronic Acid on Clinical, Biomolecular and Microbiological Parameters in Type 2 Diabetes Mellitus Patients with Periodontitis.

This double-blind randomized clinical trial assessed the effectiveness of 0.2% hyaluronic acid (HA) gel as an adjunct to scaling and root planning (SRP) in patients with periodontitis and type 2 diabetes mellitus (DM), focusing on changes in clinical periodontal parameters, the expression of inflammatory mediators, and oral pathogens. The randomized clinical trial involved 36 participants, 18 DM patients, and 18 healthy patients. The participants in each group were randomly assigned to receive placebo or HA gel after SRP. Gingival crevicular fluid and subgingival plaque samples were taken before treatment and at 4-week follow-up. Clinical parameters, interleukin-1β (IL-1β) and IL-10 levels, and proportions of Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn) were evaluated at baseline and follow-up. Paired t-test (parametric data) or Wilcoxon signed-rank test (nonparametric data) was used for intragroup comparison between baseline and follow-up, and comparisons between groups one-way analysis of variance test (parametric data) or Kruskal-Wallis test (nonparametric data). At 4 weeks, most of the groups showed statistically significant decreases (p ≤ 0.05) in various clinical and biomolecular parameters. However, there were exceptions: the pocket probing depth (PPD) and clinical attachment loss (CAL) parameter did not significantly decrease for the placebo (p > 0.05) non-DM group, and the IL-10 parameter in the DM HA gel group (p = 0.108). Regarding bacterial proportions, the non-DM and DM placebo group exhibited significant test results for Pg after 4 weeks (p ≤ 0.05). In the case of Fn bacteria proportions, they decreased in all groups, but these results were not statistically significant (p ≥ 0.05). An intergroup analysis revealed no significant differences (p ≤ 0.05) for bleeding on probing (BOP), PPD, and both proinflammatory and anti-inflammatory cytokines. Only clinical attachment loss (CAL) exhibited a statistically significant intergroup difference 0.042. The use of 0.2% HA gel into periodontal pockets alongside SRP, for both diabetic and healthy individuals, showed no statistically significant variances in clinical, biomolecular, and microbiological measures.

Differences Between Vietnamese Living in Germany and German Periodontitis Patients in Periodontal Conditions and Subgingival Microbiota

Introduction and aimsA number of studies have reported ethnic differences in the prevalence and severity of periodontitis. Such discrepancies could be attributed to disparities in periodontal risk factors, as well as variations in the composition of the subgingival microbiota. Given the substantial Vietnamese population residing in the former German Democratic Republic, the present study aimed to compare the clinical and microbial characteristics of periodontitis patients of Vietnamese Asian origin living in Germany with those of German Caucasian periodontitis patients. MethodsA total of 60 patients with a minimum stage II periodontitis diagnosis were included in the study. Of these, 30 were of Vietnamese origin, with an average age of 55 years and a male prevalence of 33.3%. The remaining 30 patients were of German origin, with an average age of 54.5 years and a male prevalence of 40%. The periodontal diagnosis was made in accordance with the recently revised classification of periodontal disease. The pooled subgingival plaque samples were subjected to next-generation sequencing on the MiSeq platform (Illumina). ResultsThe German patients were significantly more likely to be smokers (56.7% vs 13.3%), had significantly higher body mass index (26 vs 22.6 kg/m²), probing depth (4.1 vs 3.6 mm), and clinical attachment loss (5 vs 4.1 mm). In terms of microbiota, the Vietnamese patients exhibited significantly lower beta diversity compared to the German patients, and smokers demonstrated a significantly higher beta diversity compared to nonsmokers. The microbiota of both groups differed most significantly in the relative abundance of Porphyromonas gingivalis (Vietnamese) and Fusobacteriia (German). ConclusionsGerman patients with periodontitis showed more severe periodontal symptoms and more pronounced periodontal risk factors compared to Vietnamese patients. Both patient groups also showed significant differences in the subgingival microbiota. Clinical relevanceCompared to Vietnamese living in Germany, German patients have a higher need for periodontal treatment and at the same time the risk factors of smoking and obesity should be reduced. More research is needed before the differences in oral microbiota between the two groups can lead to individualised therapeutic approaches.

Examining the Relationship: Porphyromonas gingivalis Presence in Subgingival and Atherosclerotic Plaques of Cadavers

Background: Atherosclerosis and periodontitis are chronic inflammatory diseases characterized by inflammation and tissue destruction. Porphyromonas gingivalis, a key pathogen in periodontal disease, is implicated in initiating inflammation and tissue damage. Objectives: Given the potential link between periodontitis and the development of atherosclerotic plaques, this study aimed to investigate the presence of P. gingivalis DNA in subgingival and atherosclerotic plaques obtained from cadavers at the Tehran Forensic Medicine Center. Methods: In this cross-sectional study, cadavers with a postmortem interval of 6 hours and atherosclerotic plaques in their coronary arteries, along with subgingival plaques exhibiting pocket depths exceeding 5 mm, were examined. Subgingival plaque samples were collected from the deepest sites, while atherosclerotic plaque samples were harvested. Real-time PCR was employed to detect the presence of P. gingivalis in all samples, and the McNemar test was used for data analysis. Results: A total of 25 cadavers were included in the analysis, and both subgingival and atherosclerotic plaque samples were assessed. P. gingivalis DNA was identified in 40% of subgingival plaque samples and 16% of atherosclerotic plaque samples. Moreover, all positive atherosclerotic plaque samples also tested positive for P. gingivalis in the subgingival plaque. McNemar's analysis revealed a statistically significant difference between the subgingival and atherosclerotic samples (P-value = 0.03). Additionally, a correlation coefficient of 0.53 was obtained. Conclusions: While the study has certain limitations, the findings indicate a significant association between the presence of P. gingivalis in subgingival and coronary atherosclerotic plaques. Further investigations are warranted to elucidate the precise role of this periopathogen in atherosclerotic plaque formation.

Association Between Healthy Eating Index-2020 and Oral Microbiome Among Postmenopausal Women

BackgroundDietary intake has been suggested to be associated with the oral microbiome, but no study has examined the association between overall diet quality and the oral microbiome. ObjectivesThis study aimed to investigate the cross-sectional association between the Healthy Eating Index-2020 (HEI-2020) and the diversity and composition of the oral microbiome among participants in the Buffalo Osteoporosis and Periodontal Disease (OsteoPerio) Study. MethodsIn 1175 postmenopausal women (mean age: 67 ± 7.0 y), we estimated the HEI-2020 scores for each woman from a food frequency questionnaire administered from 1997 to 2000. Bacterial DNA was extracted from subgingival plaque samples and analyzed using 16S ribosomal RNA sequencing. The alpha-diversity (within-sample diversity) and β-diversity (between-sample diversity) across HEI-2020 quartiles were examined using analysis of covariance and permutational multivariate analysis of variance, respectively. The associations between the HEI-2020 score and the relative abundance of microbial taxa were examined by linear regression models. The analyses were further conducted for individual components of the HEI-2020. ResultsNo statistically significant associations were observed between the HEI-2020 scores and alpha- or beta-diversity. However, greater consumption of seafood, plant proteins, and total protein and lower consumption of added sugars were positively associated with alpha-diversity. After we applied a false detection rate (FDR) correction, higher HEI-2020 scores were significantly associated with decreased abundance of Lautropia, Streptococcus gordonii, Cardiobacterium valvarum, and Cardiobacterium hominis, and increased abundance of Selenomonas sp. oral taxon 133 and Selenomonas dianae (FDR-adjusted P values < 0.10). Additionally, 28 other taxa were identified as being associated with HEI-2020 components. ConclusionsAlthough the HEI-2020 was associated with the composition, but not the diversity, of the oral microbiome, individual HEI-2020 components were associated with both its diversity and composition. Specific dietary components may have more impact on the diversity and composition of oral microbiome than overall diet quality assessed by the HEI-2020.

Evaluation of a Novel Immunochromatographic Device for Detecting Porphyromonas gingivalis in Patients with Periodontal Disease.

Porphyromonas gingivalis is the most pathogenic periodontal bacterium in the world. Recently, P. gingivalis has been considered responsible for dysbiosis during the development of periodontitis. This study aimed to evaluate a novel immunochromatographic device using monoclonal antibodies against P. gingivalis in subgingival plaques. A total of 72 patients with chronic periodontitis and 53 periodontally healthy volunteers underwent clinical and microbiological examinations. Subgingival plaque samples were analyzed for the presence of P. gingivalis and compared using real-time polymerase chain reaction (PCR). In the periodontitis group, a significant positive correlation was observed between the test device scores and the real-time PCR results. The specificity, positive predictive value, negative predictive value, and accuracy of the test device for P. gingivalis, as determined by real-time PCR, were 98%, 94%, 89%, and 90%, respectively. There were significant differences in bacterial counts by real-time PCR among the groups with different ranges of device scores. Additionally, there was a significant positive correlation between the device scores for P. gingivalis and periodontal parameters. These results suggest that this novel immunochromatographic device can be effectively used for rapid detection and semi-quantification of P. gingivalis in subgingival plaques.

Real-world diagnostic potential of bacterial biomarkers of canine periodontitis.

The objective of this study was to investigate the diagnostic potential of bacterial biomarkers by comparing the performance of molecular detection assays with clinical assessments of dog's oral health performed by veterinarians. Supragingival and subgingival plaque samples were collected from 127 client-owned dogs, pre-booked for procedures under general anesthesia, visiting veterinary practices in the United States. DNA was extracted and bacterial biomarkers quantified using quantitative polymerase chain reaction. Gingivitis and periodontitis were recorded by a trained clinician using the Weighted Gingivitis Periodontitis Score which involved assessing the buccal surfaces of 18 teeth while under general anesthesia. Intraoral dental radiographs of the left and right mandibular first molar teeth were also obtained. These data were then used to establish the diagnostic performance of the molecular assay to detect periodontitis. An initial conscious, visual oral examination performed by the veterinarian identified 67.7% of dogs as having periodontitis, but examination under general anesthesia indicated a higher proportion (86.6%). Analysis of supragingival plaque samples collected by veterinarians from conscious and unconscious dogs demonstrated the assay had an accuracy of 77.7 to 80.9%, a sensitivity of 77.6 to 81.0%, and a specificity of 80.0%. Use of this molecular screening tool in conscious dogs has the potential to improve early periodontal disease detection and support veterinary decision making, ultimately improving the oral health of dogs and consequently their quality of life.

Familial clustering of dysbiotic oral and fecal microbiomes in juvenile dermatomyositis

Juvenile dermatomyositis (JDM) is a rare immune-mediated disease of childhood with putative links to microbial exposures. In this multi-center, prospective, observational cohort study, we evaluated whether JDM is associated with discrete oral and gut microbiome signatures. We generated 16S rRNA sequencing data from fecal, saliva, supragingival, and subgingival plaque samples from JDM probands (n = 28). To control for genetic and environmental determinants of microbiome community structure, we also profiled microbiomes of unaffected family members (n = 27 siblings, n = 26 mothers, and n = 17 fathers). Sample type (oral-vs-fecal) and nuclear family unit were the predominant variables explaining variance in microbiome diversity, more so than having a diagnosis of JDM. The oral and gut microbiomes of JDM probands were more similar to their own unaffected siblings than they were to the microbiomes of other JDM probands. In a sibling-paired within-family analysis, several potentially immunomodulatory bacterial taxa were differentially abundant in the microbiomes of JDM probands compared to their unaffected siblings, including Faecalibacterium (gut) and Streptococcus (oral cavity). While microbiome features of JDM are often shared by unaffected family members, the loss or gain of specific fecal and oral bacteria may play a role in disease pathogenesis or be secondary to immune dysfunction in susceptible individuals.

The Assessment of IL-4 and IgG1 Levels in Patients with Rheumatoid Arthritis and Periodontitis: A Serological Study in Hilla City, Iraq

Abstract Background: Periodontal disease, which has a complex etiology, is prevalent and influenced by several factors, including microorganism invasion, host health, and external environmental factors, contributing to its development. It is unknown whether rheumatoid arthritis (RA) and periodontitis are related. Objectives: The current study aims to assess the relationship between periodontitis and RA by measuring the concentrations of interleukin 4 (IL-4) and immunoglobulin G1 (IgG1) in patients’ serum and quantifying Porphyromonas gingivalis in subgingival plaque samples. Materials and Methods: The study comprised patients with periodontitis, RA, and healthy controls. The levels of IL-4 and IgG1 in the serum samples were measured using an enzyme-linked immunosorbent assay. The identification of subgingival plaque bacteria is made by using the polymerase chain reaction technique. Results: The results showed the levels of IgG1 were high in healthy people compared to those with periodontitis and those with periodontitis and arthritis, where the levels in healthy people were 2.3 ± 0.28, 2.06 ± 0.55, 2.05 ± 2.34, 1.82 ± 0.77 in the age groups 41:50, 20:30, 51:60, 31:40, respectively. It was found that there are significant differences between the values of IgG1 and IL-4 in patients with periodontitis at P ≤ 0.05 which is considered a differential sign. Conclusion: The concentrations of IL-4 and IgG1 are decreased in patients (periodontitis and periodontitis with rheumatoid arthritis) compared to their concentrations in healthy people. Thus, we indicate IL-4 was related to reducing the severity of periodontitis disease and RA.

Prevalence of Subgingival Aggregatibacter actinomycetemcomitans: Descriptive Cross-Sectional Study.

This paper aims to investigate the presence of Aggregatibacter actinomycetemcomitans and to assess potential indicators of the risk of severe form(s) of periodontitis. A descriptive cross-sectional study of 156 consecutive patients with periodontitis was conducted. Subgingival plaque samples were collected from the participants. The identification of A. actinomycetemcomitans was performed using quantitative polymerase chain reaction. A descriptive analysis, a chi-square test, and a binary logistic regression statistical evaluation were performed. The prevalence of A. actinomycetemcomitans in this population of 156 participants was 17.30% (27 patients). The prevalence of stage-III periodontitis was 75.6% and greater in older men, while the prevalence of stage-IV periodontitis was 22.4% and greater in younger women. We observed a significant relation between the risk of severe periodontitis (stage-IV) and poor oral hygiene (p = 0.006), attendance at dental appointments (p ≤ 0.001), and familial history of periodontitis (p = 0.032). In conclusion, twenty-seven individuals were positive for A. actinomycetemcomitans. Poor oral hygiene, family history of periodontitis, and irregular attendance at dental appointments were identified as potential risk factors for severe periodontitis in this cohort.

Periodontal and microbiological evaluation in cleft lip/palate patients undergoing orthodontic treatment: A cross‐sectional study

AbstractBackgroundThe present cross‐sectional study was undertaken to evaluate the periodontal and microbiological parameters in patients with surgically repaired unilateral cleft lip and palate (UCLP) undergoing orthodontic correction in comparison to patients without any cleft or orthodontic treatment.MethodsA total of 120 patients, out of initial 148 patients, between the age group 6 and 18 years were enrolled and divided into four groups with 30 patients each: non‐cleft patients without orthodontic treatment in Group 1, non‐cleft patients undergoing fixed orthodontic treatment in Group 2, patients with UCLP without any orthodontic treatment in Group 3, and patients with UCLP undergoing fixed orthodontic treatment in Group 4. Periodontal parameters including plaque index (PI), gingival index (GI), gingival bleeding index (GBI), community periodontal index of treatment needs (CPITN) index, pocket probing depth (PD), and tooth mobility were measured in all the groups. The subgingival plaque samples of all the patients were subjected to microbial evaluation using matrix‐assisted laser desorption ionization‐time of flight mass spectrometry (MALDI‐TOF‐MS) for clinical diagnosis.ResultsThe periodontal parameters were significantly raised in Group 4, followed by Group 3 and Group 2 in comparison to Group 1 (p &lt; 0.01), thereby suggesting poor periodontal health in patients with UCLP undergoing orthodontic treatment. Statistically significant differences (p &lt; 0.01) in counts of micro‐organisms among the groups were observed for P. gingivalis, P. intermedia, Veillonella, and Capnocytophaga, with the highest proportions in Group 4, indicating a deteriorating oral health in these patients.ConclusionPoor periodontal and microbial health in patients with UCLP undergoing orthodontic treatment indicates a need for reinforcement of oral hygiene practices among these patients.

Differences in maternal subgingival microbiome between preterm and term births: The MOHEPI study.

Periodontitis is a potential risk factor for preterm birth (PTB) in women; however, the causal relationship or the exact mechanism remain unknown. This study aimed to compare the oral microbiome features of mothers with full-term birth (FTB) with those who had preterm delivery. This study prospectively enrolled 60 women (30 mothers with PTB and 30 mothers with FTB), and subgingival plaque samples were collected and analysed by metagenomic 16S rDNA sequencing. Clinical measurements, including periodontal probing depth, clinical attachment level, modified gingival index (mGI) and plaque index, were performed to determine the periodontal state of the participants. Medical and obstetric data were collected as well. Among the periodontal measurements, mGI score, reflecting the level of gingival inflammation, exhibited a statistically significant association with PTB (adjusted odds ratio 2.705, 95% confidence interval 1.074-6.811, p = .035). When subgroup analysis was conducted based on mean mGI scores (mGI ≥ 2, high inflammation [HI] versus mGI < 2, low inflammation [LI]), microbiome analysis revealed clear distinctions in microbial compositions between PTB and FTB mothers in both the HI and LI groups. Especially in the HI group, alpha diversity exhibited a decreasing trend in PTB mothers compared to FTB mothers. Beta diversity also revealed significant differences between the two groups. In Linear Discriminant Analysis Effect Size analysis, certain anaerobic taxa, including the genera Spirochaetes, Treponema and Porphyromonas, were relatively abundant in the FTB/HI group, whereas the PTB/HI group showed a high abundance of the order Actinomycetales. Network analysis showed that the FTB/HI had relatively stronger connectivity in microbial composition than the PTB/HI group. Dysbiosis ratio of plaque microbiome, in terms of periodontitis, was significantly lower in PTB/HI group compared to FTB/HI group. The compositions of maternal subgingival microbiomes differed between PTB and FTB mothers in both the high and low levels of gingival inflammation groups. In the presence of high level of gingival inflammation, dysbiosis in plaque microbiome, in terms of periodontitis, was decreased in PTB mothers compared to FTB mothers.

Distinctive subgingival microbial signatures in older adults with different levels of cognitive function.

To examine association between subgingival microbial signatures and levels of cognitive impairment in older adults. We analysed subgingival plaque samples and 16S ribosomal RNA sequences for microbiota among 165 participants (normal controls [NCs]: 40, subjective cognitive decline [SCD]: 40, mild cognitive impairment [MCI]: 49 and dementia: 36). The bacterial richness was lower among individuals with worse cognitive function, and subgingival microbial communities differed significantly among the four groups. Declining cognitive function was associated with decreasing relative abundance of genera Capnocytophaga, Saccharibacteria_genera_incertae_sedis, Lautropia and Granulicatella, and increasing abundance of genus Porphyromonas. Moreover, there were differentially abundant genera among the groups. Random forest model based on subgingival microbiota could distinguish between cognitive impairment and NC (AUC = 0.933, 95% confidence interval 0.873-0.992). Significant correlations were observed between oral microbiota and sex, Montreal Cognitive Assessment (MoCA) score and Mini-Mental State Examination score. Partial correlation analysis showed that Leptotrichia and Burkholderia were closely negatively associated with the MoCA score after adjusting for multiple covariates. Gene function was not significantly different between SCD and NC groups, whereas three homozygous genes were altered in MCI patients and two in dementia patients. This is the first study to demonstrate an association between the composition, function and metabolic pathways of subgingival microbiota and different levels of cognitive function among older individuals. Future cohort studies should assess its diagnostic usefulness for cognitive impairment.

Microbiome of periodontitis and peri-implantitis before and after therapy: Long-read 16S rRNA gene amplicon sequencing.

The microbial profiles of peri-implantitis and periodontitis (PT) are inconclusive. The controversies mainly arise from the differences in sampling sites, targeted gene fragment, and microbiome analysis techniques. The objective of this study was to explore the microbiomes of peri-implantitis (PI), control implants (CI), PT and control teeth (CT), and the microbial change of PI after nonsurgical treatment (PIAT). Twenty-two patients diagnosed with both PT and peri-implantitis were recruited. Clinical periodontal parameters and radiographic bone levels were recorded. In each patient, the subgingival and submucosal plaque samples were collected from sites with PI, CI, PT, CT, and PIAT. Microbiome diversity was analyzed by high-throughput amplicon sequencing using full-length of 16S rRNA gene by next generation sequencing. The 16S rRNA gene sequencing analysis revealed 512 OTUs in oral microbiome and 377 OTUs reached strain levels. The PI and PT groups possessed their own unique core microbiome. Treponema denticola was predominant in PI with probing depth of 8-10 mm. Interestingly, Thermovirga lienii DSM 17291 and Dialister invisus DSM 15470 were found to associate with PI. Nonsurgical treatment for peri-implantitis did not significantly alter the microbiome, except Rothia aeria. Our study suggests Treponemas species may play a pivotal role in peri-implantitis. Nonsurgical treatment did not exert a major influence on the peri-implantitis microbiome in short-term follow-up. PT and peri-implantitis possess the unique microbiome profiles, and different therapeutic strategies may be suggested in the future.

Real-Time PCR Method as Diagnostic Tool for Detection of Periodontal Pathogens in Patients with Periodontitis.

The most common type of periodontal disease is chronic periodontitis, an inflammatory condition caused by pathogenic bacteria in subgingival plaque. The aim of our study was the development of a real-time PCR test as a diagnostic tool for the detection and differentiation of five periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Treponema denticola, in patients with periodontitis. We compared the results of our in-house method with the micro-IDent® semiquantitative commercially available test based on the PCR hybridization method. DNA was isolated from subgingival plaque samples taken from 50 patients and then analyzed by both methods. Comparing the results of the two methods, they show a specificity of 100% for all bacteria. The sensitivity for A. actinomycetemcomitans was 97.5%, for P. gingivalis 96.88%, and for P. intermedia 95.24%. The sensitivity for Tannerella forsythia and T. denticola was 100%. The Spearman correlation factor of two different measurements was 0.976 for A. actinomycetemcomitans, 0.967 for P. gingivalis, 0.949 for P. intermedia, 0.966 for Tannerella forsythia, and 0.917 for T. denticola. In conclusion, the in-house real-time PCR method developed in our laboratory can provide information about relative amount of five bacterial species present in subgingival plaque in patients with periodontitis. It is likely that such a test could be used in dental diagnostics in assessing the efficacy of any treatment to reduce the bacterial burden.

Microbiological Effects of Sodium Hypochlorite/-Amino Acids and Cross-linked Hyaluronic Acid Adjunctive to Non-surgical Periodontal Treatment.

To investigate the microbiological outcomes obtained with either subgingival debridement (SD) in conjunction with a gel containing sodium hypochlorite and amino acids followed by subsequent application of a cross-linked hyaluronic acid gel (xHyA) gel, or with SD alone. Forty-eight patients diagnosed with stages II-III (grades A/B) generalised periodontitis were randomly treated with either SD (control) or SD plus adjunctive sodium hypochlorite/amino acids and xHyA gel (test). Subgingival plaque samples were collected from the deepest site per quadrant in each patient at baseline and after 3 and 6 months. Pooled sample analysis was performed using a multiplex polymerase chain reaction (PCR)-based method for the identification of detection frequencies and changes in numbers of the following bacteria: Aggregatibacter actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g), Tannerella forsythia (T.f), Treponema denticola (T.d), and Prevotella intermedia (P.i). In terms of detection frequency, in the test group, statistically significant reductions were found for P.g, T.f, T.d and P.i (p < 0.05) after 6 months. In the control group, the detection frequencies of all investigated bacterial species at 6 months were comparable to the baseline values (p > 0.05). The comparison of the test and control groups revealed statistically significant differences in detection frequency for P.g (p = 0.034), T.d (p < 0.01) and P.i (p = 0.02) after 6 months, favouring the test group. Regarding reduction in detection frequency scores, at 6 months, statistically significant differences in favour of the test group were observed for all investigated bacterial species: A.a (p = 0.028), P.g (p = 0.028), T.f (p = 0.004), T.d (p <0.001), and P.i (p = 0.003). The present microbiological results, which are related to short-term outcomes up to 6 months post-treatment, support the adjunctive subgingival application of sodium hypochlorite/amino acids and xHyA to subgingival debridement in the treatment of periodontitis.

Periodontal Health and Microbiological Characteristics of Siwak (Chewing Stick) and Toothbrush Users: A Cross-Sectional Study

Abstract Objective Siwak is a chewing stick used to clean the teeth and oral structures. Many studies have been conducted to assess the potential use of siwak in dentistry and concluded that it can be an alternative to a toothbrush in reducing plaque and gingivitis. However, some observations have reported more periodontal attachment loss and gingival recession among siwak users. This study aimed to compare the periodontal health and oral microbial characteristics between siwak and toothbrush users. Materials and Methods This was a cross-sectional study, and participants were recruited from the public who attended community engagement programs. They were assigned to two groups based on whether they used siwak or a toothbrush. Participants who consented were examined for periodontal health. Supragingival and subgingival plaque samples were collected for bacterial identification and quantification. Statistical Analysis The SPSS package version 21.0 was used for data entry. Data normality was statistically tested using Kolmogorov–Smirnov and Shapiro–Wilk tests, while data comparison used either t-test or Mann–Whitney U test. Results A total of 36 participants were included in this study. The findings revealed that the plaque scores, bleeding scores, and periodontal pocket depths between siwak and toothbrush users were comparable (p &gt; 0.05). Both groups had no evidence of gingival recession. Most participants had bacteria with characteristics of Streptococcus spp., which were present in 12 toothbrush users and 6 siwak users. Conclusions The periodontal health status of siwak users was comparable to that of toothbrush users. Despite this, siwak users had fewer types of bacteria than toothbrush users, suggesting that siwak may serve as an alternative device to conventional toothbrushes for oral hygiene when properly used.