Advances in the pathogenesis of periodontitis: summary of developments, clinical implications and future directions

Customized Hydrogel System for the Spatiotemporal Sequential Treatment of Periodontitis Propelled by ZEB1

Advanced periodontitis initiates with Porphyromonas gingivalis (P. gingivalis) infection, which subsequently triggers chronic inflammation, immune imbalance, and ultimately causes alveolar bone resorption. Traditional periodontal treatment focuses on the elimination of triggering factors, but tend to ignore the improvement of the inflammatory microenvironment and the remodeling of the osteogenic mineralization space. Herein, zinc-aluminum layered double hydroxide nanosheets (LDHs) loaded with icariin (ICA) are encapsulated into a gallic acid (GA)-modified hydroxybutyl chitosan hydrogel (GA-HBC), giving rise to a customized hydrogel system named GA-HBC-LIC, which can sequentially actualize antibacterial, anti-inflammatory, and remineralization functions. A neutral chemical-humoral space is created for osteogenesis via means of sequential regulation by the smart hydrogel. Concomitantly, appropriate mechanical properties and degradation performance of the hydrogel provide a desirable physical space for remineralization. In the spatiotemporal modulation of the hydrogel, zinc finger E-box-binding homeobox 1 (ZEB1) target of released zinc ions (Zn2+) action promotes macrophage polarization from M1 to M2 phenotype, thereby remodeling the immune microenvironment and releasing cytokines conducive to tissue regeneration. In sum, this study highlights the critical role of sequential inflammation regulation and the maintenance of osteogenic space in the regeneration of periodontal tissues, offering new insights for the clinical management of periodontitis.

The Effect of Photobiomodulation on Periodontal Clinical Status of Patients with Cancer During Chemotherapy: A Randomized Clinical Trial

Objective: This interventional prospective double-blind randomized study investigated the adjunctive inflammation-modulatory effects of photobiomodulation therapy on the periodontal clinical parameters of patients undergoing chemotherapy. Methods: Twenty diagnosed patients with cancer were enrolled in this split-mouth trial. Patients were randomized to implantation with either SRP alone in one quadrant or with five sessions of adjunctive photobiomodulation using a diode laser (density of energy = 2 J/cm2 | wavelength = 635 nm | power = 50 mW | spot diameter = 4 mm | exposure time = 5 s | continuous mode) on the other quadrant. The gingiva was radiated buccally and lingually. The laser beam was positioned 3 mm vertically away from the gingival surface and at a right angle to it. Before chemotherapy, all participants were given oral hygiene training and received SRP. In the same session, the patient's baseline clinical measures were taken immediately after the beginning of one chemotherapy session, interventions for each side were started and clinical parameters including gingival index (GI), plaque index (PI), clinical attachment level (CAL), and pain/burning sensation after one chemotherapy session were obtained. Results: Regarding GI and PI, both control and test groups showed favorable results compared with baseline. However, the adjunctive photobiomodulation group outperformed the control group in one chemotherapy session regarding both abovementioned indices (p < 0.05). The photobiomodulation+scaling and root planing (SRP) group showed promising results in terms of gingival discomfort reduction and SRP alone was not effective. No significant effect was observed regarding CAL in both groups (p > 0.05). Conclusion: Based on the results of this study, it can be concluded that photobiomodulation promotes gingival health and reduces PI and GI indices. Photobiomodulation also alleviates pain or burning in the gingiva. Accordingly, adjunctive photobiomodulation therapy may be suggested as a supplementary treatment in patients with cancer.

Genetic risk factors for periodontitis: a genome-wide association study using UK Biobank data

OBJECTIVES

Periodontitis is linked with many health conditions, but its genetic basis is not yet understood. This genome-wide association study (GWAS) aimed to investigate the genetic variants associated with periodontitis.

MATERIALS AND METHODS

This study utilised UK Biobank participants of European descent. Individuals were categorised as "having periodontitis" if they self-reported having 'painful gums', 'bleeding gums' or 'loose teeth' (n = 68,482), or as "controls" for those without these symptoms (n = 307,342). We conducted GWAS of this binary periodontitis phenotype using logistic regression models with PLINK2.0 adjusting for age, sex and the first 15 principal components to account for population stratification.

RESULTS

There were 376,611 participants (mean baseline age = 57 ± 7.9 SD) included in the GWAS, and four significant loci were identified: rs775476621 on chromosome 11 (Odds Ratio, OR[T]: 3.08, p = 1.01 × 10- 8), rs751014048 on chromosome 11 (OR[G]: 3.07, p = 1.04 × 10- 8), rs149922301 on chromosome 4 near gene RP11-61G19.1 (OR[A]: 1.18, p = 2.71 × 10- 8) and rs368467810 on chromosome 6 near gene HIST1H3L (OR[TTTA]: 0.96, p = 3.88 × 10- 8).

CONCLUSIONS

Within the current limitations, such as self-reported phenotype and older age of the study population, four loci were detected for periodontitis that have not previously been linked with this condition. Further exploration of the function of these loci may contribute to improved understanding of periodontitis aetiology and subsequent drug development.

CLINICAL RELEVANCE

These findings offer new targets for future research to investigate the genetic impact on periodontitis and aid the future understanding of periodontitis pathology and the disease's progression.

Bidirectional effects of neutrophils on Streptococcus oralis biofilms in vitro

Background

Streptococcus oralis is a commensal bacterium and an early biofilm coloniser found in the human oral cavity. One of the biofilm matrix constituents is bacterial extracellular DNA (eDNA). Neutrophils are innate immune cells that respond to biofilms, employing antimicrobial mechanisms such as neutrophil extracellular trap (NET) and reactive oxygen species (ROS) release. Here, bidirectional effects of neutrophils on S. oralis biofilms were investigated.

Materials and methods

Isolated neutrophils were introduced to S. oralis biofilms at different stages of biofilm development. Biofilm quantity was assessed by crystal violet technique, confocal microscopy and CFU enumeration. Surface adhesion during shear stress was quantified by spectrophotometry. Bacterial and neutrophil extracellular DNA within biofilms and ROS production were analysed using fluorescence and luminescence assays, and neutrophil-eDNA interactions were investigated by flow cytometry and fluorescence microscopy.

Results

Neutrophils decreased S. oralis biofilm quantity transiently and reduced eDNA but did not affect biofilm surface adhesion. Unexpectedly, CFUs were increased by neutrophils. Bacterial DNA was found to co-localise with neutrophil membranes. Neutrophils produced elevated total and intracellular ROS, however, no NETs in response to biofilms.

Conclusion

Neutrophils in vitro are not excessively activated by S. oralis biofilms but are able to reduce biofilm quantity in the short-term, possibly through interfering with eDNA.

Identification of key signaling pathways and novel computational drug target for oral cancer, metabolic disorders and periodontal disease

AIM

Due to conventional endocrinological methods, there is presently no shared work available, and no therapeutic options have been demonstrated in oral cancer (OC) and periodontal disease (PD), type 2 diabetes (T2D), and obese patients. The aim of this study is to determine the similar molecular pathways and potential therapeutic targets in PD, OC, T2D, and obesity that may be used to anticipate the progression of the disease.

METHODS

Four Gene Expression Omnibus (GEO) microarray datasets (GSE29221, GSE15773, GSE16134, and GSE13601) are used for finding differentially expressed genes (DEGs) for T2D, obese, and PD patients with OC in order to explore comparable pathways and therapeutic medications. Gene ontology (GO) and pathway analysis were used to investigate the functional annotations of the genes. The hub genes were then identified using protein-protein interaction (PPI) networks, and the most significant PPI components were evaluated using a clustering approach.

RESULTS

These three gene expression-based datasets yielded a total of seven common DEGs. According to the GO annotation, the majority of the DEGs were connected with the microtubule cytoskeleton structure involved in mitosis. The KEGG pathways revealed that the concordant DEGs are connected to the cell cycle and progesterone-mediated oocyte maturation. Based on topological analysis of the PPI network, major hub genes (CCNB1, BUB1, TTK, PLAT, and AHNAK) and notable modules were revealed. This work additionally identified the connection of TF genes and miRNAs with common DEGs, as well as TF activity.

CONCLUSION

Predictive drug analysis yielded concordant drug compounds involved with T2D, OC, PD, and obesity disorder, which might be beneficial for examining the diagnosis, treatment, and prognosis of metabolic disorders and Oral cancer.

Measures of Bacterial Endotoxins in Gingival Crevicular Fluid and Peripheral Blood of Aggressive Periodontitis Cases-A Clinical Association

Introduction

The present study was undertaken with the objective to evaluate the level of endotoxin produced in the gingival crevicular fluid (GCF) and peripheral blood of subjects with generalized aggressive periodontitis (GAgP) in comparison with periodontally healthy subjects at baseline, three months, and six months post-periodontal surgical treatment.

Materials and Methods

A total of 24 subjects aged between 20 and 50 years were selected for the study. They were divided into two groups: generalized aggressive periodontitis (GAgP) subjects (Group A) and periodontally and systemically healthy individuals (Group B). Endotoxin levels were assessed in GCF and peripheral blood of both the groups at baseline, three months, and six months postsurgical treatment. The clinical parameters, such as plaque index (PI), gingival index (GI), probing pocket depth (PPD), and clinical attachment level (CAL), were also recorded at same time intervals. A correlation between the clinical parameters and endotoxin in GCF and peripheral blood was established in diseased cases as compared to healthy individuals.

Results

Favorable clinical outcomes with the reduction of PI, GI, PPD, and CAL were achieved for Group A post-surgery when compared to baseline. The GCF endotoxin level in Group A was observed to be significantly higher than Group B and reduced favorably after treatment. In peripheral blood, there was no significant difference in endotoxin level between both the groups.

Conclusion

It can be concluded from the results that the level of bacterial endotoxin was significantly raised in GCF, indicating its role in the causation of rapid destruction of the periodontium in aggressive periodontitis subjects.

Inflammation and tissue remodeling mediator expression during gingivitis: A comparison between experimental, naturally occurring gingivitis, and periodontal health

BACKGROUND

The aim of this study is to evaluate the immune regulation and tissue remodeling responses during experimental gingivitis (EG) and naturally occurring gingivitis (NG) to provide a comprehensive analysis of host responses. Gingival crevicular fluid (GCF) was obtained from 2 human studies conducted in university settings.

METHODS

The EG study enrolling 26 volunteers provided controls for the baseline (Day 0) from healthy disease-free participants, while Day 21 (the end of EG induction of the same group) was used to represent EG. Twenty-six NG participants age-matched with those of the EG group were recruited. GCF samples were analyzed for 39 mediators of inflammatory/immune responses and tissue remodeling using commercially available bead-based multiplex immunoassays. The differences in GI and mediator expression among groups were determined at a 95% confidence level (p ≤ 0.05) by a 2-way analysis of variance (ANOVA) with a post-hoc Tukey's test.

RESULTS

Our findings showed that EG had a greater gingival index than NG and was healthy (p < 0.01 of all comparisons). Furthermore, EG showed significantly higher levels of MPO (p < 0.001), CCL3 (p < 0.05), and IL-1B (p < 0.001) than NG. In contrast, NG had increased levels of MIF (p < 0.05), Fractalkine (p < 0.001), angiogenin (p < 0.05), C3a (p < 0.001), BMP-2 (p < 0.001), OPN (p < 0.05), RANKL (p < 0.001), and MMP-13 (p < 0.001) than EG.

CONCLUSIONS

Consistent with the findings from chronic (NG) versus acute (EG) inflammatory lesions, these data reveal that NG displays greater immune regulation, angiogenesis, and bone remodeling compared to EG.

Identification of susceptibility modules and genes for peri-implantitis compared to periodontitis within the same host environment using weighted gene co-expression network analysis

PURPOSE

This study aimed to identify new susceptibility modules and genes by analyzing the transcriptional profiles of peri-implantitis and periodontitis within the same host environment, using weighted gene co-expression network analysis (WGCNA).

METHODS

Gingival tissue samples were collected from 10 patients, each presenting with both periodontitis and peri-implantitis sites, and were used for RNA sequencing. We conducted WGCNA to identify key modules that showed distinct transcriptional expression profiles between periodontitis and peri-implantitis. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses were carried out using R software. Genes with an adjusted P value greater than 0.05 were excluded from gene selection using the Pearson correlation method.

RESULTS

A total of 2,226 regulated genes were identified, and those with similar expression patterns were grouped into 5 color-coded functional modules using WGCNA. Among these, 3 modules showed distinct differences in expression profiles between peri-implantitis and periodontitis. The turquoise and yellow modules were associated with upregulation in peri-implantitis, while the blue module was linked to periodontitis. This finding suggests that peri-implantitis and periodontitis have significantly different transcriptional signatures. Over-representation analysis was conducted to explore the component genes of the established modules. The top-ranked genes, selected based on their network connectivity within the modules, were identified using DESeq2 and were considered hub genes.

CONCLUSIONS

WGCNA revealed distinct modular gene patterns in peri-implantitis and periodontitis, highlighting transcriptional differences between the 2 conditions. Notably, we identified 10 key genes from each of the 3 modules-the blue module associated with periodontitis-dominant pathways, and the turquoise and yellow modules associated with peri-implantitis-dominant pathways. The hub genes and pathways unveiled in this research are likely key contributors to the progression of peri-implantitis and warrant further exploration as promising candidates.

Association of crown-root ratio and tooth survival in Chinese patients with advanced periodontitis: An 11-year retrospective cohort study

INTRODUCTION

Periodontitis is a chronic multifactorial inflammatory disease which eventually lead to tooth loss (TL). Therefore, a retrospective study was conducted to evaluate the status of tooth survival within 11 years after non-surgical periodontal treatment (NSPT) and to analyze the risk factors especially crown-root ratio (CRR) that affected TL in Chinese with advanced periodontitis.

METHODS

3481 teeth of 131 subjects who underwent NSPT were examined retrospectively within a mean follow-up period of 11.6 years. The association of risk factors including clinical and radiographic parameters with TL was assessed using univariate and multivariate Cox regression analyses. Smooth curve fitting and segmented regression model were conducted to show the nonlinear relationship and the threshold effect between CRR and the risk of TL.

RESULTS

347 teeth were lost in 97 patients in this study. Male, diabetes mellitus, heavy-smoker, molar, probing depth (PD), attachment loss (AL), bleeding on probing (BOP), tooth mobility, and radiographic bone loss were significantly associated with tooth loss (P < 0.05). A nonlinear relationship between CRR and the risk of TL was found, with different turning point values between molars and non-molars (1.9 vs. 2.76).

CONCLUSIONS

The findings based on practice-based clinical and radiographic data do suggest a nonlinear relationship between CRR and the survival of teeth, and provide evidence to help clinicians to determine the prognosis of teeth for patients with advanced periodontitis.

CLINICAL SIGNIFICANCE

Based on clinical and radiographic data, this study provides an individualized basis for clinicians to judge the dental prognosis of patients with advanced periodontitis according to the different tooth sites.

The association between periodontal microbial biomarkers and primary therapy outcome

OBJECTIVE

This study aims to analyse the association between the baseline microbial load of selected periodontopathogenic bacteria collected from gingival crevicular fluid (GCF) and the primary outcome of steps I and II therapy.

MATERIALS AND METHODS

222 patients with stage III periodontitis were included into this retrospective analysis that received steps 1 and 2 periodontal therapy without adjunctive systemic antibiotics. Baseline GCF samples were quantitatively analysed using ELISA-based kits for levels of periodontopathogens (Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Treponema denticola (Td), and Tannerella forsythia (Tf)) and associated with the primary therapy outcome using a "treat-to-target" therapy endpoint (TE) defined as ≤ 4 sites with PD ≥ 5 mm six months after therapy.

RESULTS

38.2% of the patients achieved TE. Patients failing to achieve TE revealed significantly increased levels of Pg, Fn, and Tf at baseline (Pg: p = 0.010, Fn: p = 0.008 Tf: p = 0.004). Multivariate binary logistic regression adjusted for sex, mean probing depth, diabetes, and current smoking status showed an independent relationship between Tf and the TE (aOR 2.570, p = 0.023).

CONCLUSION

Increased microbial load is associated with decreased responsiveness to therapy. The findings suggest that specifically baseline Tf levels are associated with poorer treatment outcomes and might improve the accuracy of periodontal diagnosis.

CLINICAL RELEVANCE

The findings of this study support the concept of a critical biomass that is sufficient to induce and maintain an immune response within the periodontal pocket, which ultimately leads to irreversible tissue destruction. However, calculating this level in advance may serve as an early indicator for intervention.

KEY FINDING

Baseline Tannerella forsythia levels are associated with poorer treatment outcome.

Toll-like receptor 4 deficiency affects the balance of osteoclastogenesis and osteoblastogenesis in periodontitis

Toll-like receptor 4 (TLR4) acts as a double-edged sword in the occurrence and development of periodontitis. While the activation of TLR4 in macrophages aids in clearing local pathogens, it can also disrupt innate immune responses, upsetting microecological balance and accelerating the destruction of periodontal bone tissues. To date, the effects of TLR4 on osteogenesis and osteoclastogenesis in periodontitis have not been comprehensively studied. In this study, we investigated the development of periodontitis in the Tlr4-/- mice by ligating their second molars with silk threads. Compared to wild-type (WT) mice, Tlr4-/- mice demonstrated increased resistance to periodontitis-associated bone destruction, as evidenced by decreased bone resorption and enhanced bone regeneration. Mechanistically, the deletion of Tlr4 not only inhibited osteoclast formation by reducing the expression of NFATc1, CTSK and TRAP, but also enhanced osteogenic abilities through increased expression of OCN, OPN and RUNX2. In conclusion, TLR4 tips the balance of osteoclastogenesis and osteogenesis, thereby promoting periodontal bone destruction in periodontitis.

Implant Mechanics, Biological Milieu, and Peri-Implantitis: A Narrative Review

Dental implants constitute an important treatment modality for rehabilitating edentulous and partially edentulous arches. With more implant systems in the market, understanding the mechanical aspects of implants is crucial in understanding this indispensable therapy. However, microflora-related factors i.e. biological factors are also crucial. Despite the tremendous success rate of dental implants, it is not averse to failure. Both mechanical and microbial aspects in seclusion or together predispose to implant failure. Newer technological advances have paved the way for advanced techniques to identify the not-so-common flora causing implant failure. This review focuses on detailed mechanical and biological aspects and the sealing agent used to seal the implant-abutment interface. It also focuses on advanced molecular techniques like metagenomics and transcriptomics. A thorough literature search was performed with selected articles from electronic databases. A combination of in-vivo and in-vitro studies were considered to provide comprehensive information on the subject. Both the biomechanical aspects like micro gap, and microleakage, as well as microbial movements play confluent roles in implant failure. The focus should be on the different aspects through which microflora can penetrate the inner parts of the implant. Also, newer culture-independent techniques of detecting previously undetected oral flora should be included in future studies.

Leveraging genetics to investigate causal effects of immune cell phenotypes in periodontitis: a mendelian randomization study

Introduction

Immune cells are dynamic in the inflammatory environment and play a key role in eradicating periodontal pathogens, modulating immune responses, and instigating tissue destruction. Identifying specific immune cell phenotypes associated with periodontitis risk is essential for targeted immunotherapeutic interventions. However, the role of certain specific immune cell phenotypes in the development of periodontitis is unknown. Mendelian randomization offers a novel approach to reveal causality and address potential confounding factors through genetic instruments.

Methods

This two-sample Mendelian randomization study assessed the causal relationship between 731 immune cell phenotypes and periodontitis using the inverse variance weighting method with the GWAS catalog genetic database. Methodological robustness was ensured through Cochran's Q test, MR-Egger regression, MR-PRESSO, and Leave-One-Out analysis.

Results

14 immune cell phenotypes showed potential positive causal associations with periodontitis risk (p < 0.05), suggesting an increased risk, while 11 immune cell phenotypes exhibited potential negative causal associations (p < 0.05), indicating a reduced risk. No significant heterogeneity or pleiotropy was observed.

Conclusion

This study underscores certain immune cell types as potential periodontitis risk biomarkers, laying a theoretical foundation for future individualized treatment and precision medicine development.

Comparative evaluation of semaphorin-4D, peptidylarginine deiminase-2, and matrix metalloproteinase-8 levels of gingival crevicular fluid in periodontally healthy and Stage III periodontitis smoker and non-smoker patients before and after non-surgical periodontal therapy

BACKGROUND

This study was designed to assess the influence of non-surgical periodontal therapy (NSPT) on gingival crevicular fluid (GCF) levels of semaphorin-4D (SEMA-4D), peptidylarginine deiminase-2 (PAD-2), and matrix metalloproteinase-8 (MMP-8) levels in periodontally healthy, Stage III periodontitis non-smoker and smoker patients.

METHODS

Sixty patients were equally divided into three groups, Group I: Periodontally healthy, Group II: Non-smokers with Stage III periodontitis, and Group III: Smokers with Stage III periodontitis. The patients underwent NSPT with clinical and biochemical parameters examined at baseline and 3 months post therapy. GCF was collected for levels of SEMA-4D, PAD-2, and MMP-8 through enzyme-linked immunosorbent assay (ELISA).

RESULTS

Greater values of PPD (8.06 ± 0.19 mm), CAL (8.94 ± 0.19 mm), PI (2.58 ± 0.19) while lower PBI (1.39 ± 0.19%) and GI (1.72 ± 0.19) scores were seen in Group III as compared to Group II, which reduced significantly from baseline to 3 months in both the groups after NSPT. Minimum values of SEMA-4D, PAD-2, and MMP-8 levels in GCF were seen for Group I, which increased incrementally to Group II and III. Also, among Group II and III the SEMA-4D, PAD-2, and MMP-8 levels in GCF reduced from baseline to 3 months indicating a favorable response within the tissues.

CONCLUSION

Greater levels in GCF of Levels of SEMA-4D, PAD-2, and MMP-8 in Group II and III, which reduced significantly post NSPT, implied that these biomarkers play a pivotal role in the inflammatory process and can be utilized for early diagnosis.

"Outcome of non-surgical periodontal treatment on Gal-1 and Gal-3 GCF levels in periodontitis patients: a case-control study"

OBJECTIVES

This study aimed to explore the effect of nonsurgical periodontal treatment on Galectin-1 and -3 GCF levels in gingivitis and periodontitis stage III compared to periodontally healthy individuals, to determine whether they could serve as diagnostic markers / therapeutic targets for periodontitis and revealing their possible role in periodontal disease.

MATERIALS AND METHODS

Forty-five systemically healthy participants were included and equally subdivided into three groups: gingivitis, periodontitis (stage III), and a periodontally healthy control group. The clinical parameters were recorded. Galectin-1 and -3 GCF levels were evaluated (before and after non-surgical treatment for periodontitis) using an enzyme linked immune-sorbent assay (ELISA) kit. Receiver operating characteristic (ROC) curve was performed to reveal sensitivity, specificity, predictive value, and diagnostic accuracy of both markers.

RESULTS

The study showed statistical significance between different groups regarding Galectin-3 with higher values in periodontitis and the lowest values in healthy control. Also, Galectin-1 was significantly higher in the periodontitis/gingivitis groups than in the control group. Moreover, non-surgical periodontal treatment in periodontitis patients caused a statistical reduction in clinical parameters and biomarkers. ROC analysis revealed excellent diagnostic ability of both biomarkers in discriminating periodontitis/gingivitis against healthy individuals (100% diagnostic accuracy for Galectin-1 and 93% for Galectin-3, AUC > 0.9) and acceptable diagnostic ability between periodontitis participants against gingivitis (73% diagnostic accuracy for Gal-1 and 80% for Gal-3, AUC > 0.7).

CONCLUSIONS

Both Galectin-1 and Galectin-3 seem to have outstanding diagnostic accuracy for the identification of periodontal disease, an acceptable ability to measure periodontal disease activity and the severity of inflammatory status. Additionally, they could serve as therapeutic targets to monitor treatment efficiency.

CLINICALTRIAL

GOV REGISTRATION NUMBER: (NCT06038812).

No genetic causal association between periodontitis and ankylosing spondylitis: a bidirectional two-sample mendelian randomization analysis

BACKGROUND

Observational studies that reveal an association between periodontitis (PD) and ankylosing spondylitis (AS) exist. However, observational research is prone to reverse causality and confounding factors, which make it challenging to infer cause-and-effect relationships. We conducted a two-sample Mendelian randomization (MR) study to examine the causal relationship between the genetic prediction of PD and AS.

METHODS

In our study, single-nucleotide polymorphisms (SNPs) were defined as instrumental variables (IVs). The genetic association with PD came from the Gene-Lifestyle Interactions and Dental Endpoints (GLIDE) consortium, wherein 17353 cases of European ancestry and 28210 controls of European ancestry were included in this study. The genetic association with AS from the Neale Laboratory Consortium included 337,159 individuals from the United Kingdom, with 968 cases and 336,191 controls. MR analysis was mainly performed using the inverse-variance weighted (IVW) method. In addition, the robustness of the study findings was assessed using sensitivity, pleiotropy, and heterogeneity analyses.

RESULTS

Eighteen independent SNPs with P-values significantly smaller than 1 × 10- 5 were used as IV SNPs for PD, while 39 independent SNPs with P-values significantly smaller than 1 × 10- 5 were used as IV SNPs for AS. The results of the IVW method revealed no causal association between PD and AS (odds ratio = 1.00, 95% confidence interval: 0.99953 to 1.00067, P = 0.72). The MR-Egger method did not support the causal association between PD and AS. It is unlikely that horizontal pleiotropy distorts causal estimates based on sensitivity analysis. No significant heterogeneity was observed in the Q test. The ''leave-one-out'' analysis demonstrated that the robustness of our results was unaffected by eliminating any of the IVs. Likewise, no significant causative effect for AS on PD was observed in the inverse MR analysis.

CONCLUSIONS

The study results do not support shared heritability or a causal association between PD and AS.

Clinical Use of Paraprobiotics for Pregnant Women with Periodontitis: Randomized Clinical Trial

Periodontal disease is very common in pregnant women. Paraprobiotics are a subset of probiotics. They can be defined as inactivated microbial cells providing health benefits to the host and are considered particularly safe. The aim of this study was to compare the periodontal health of pregnant women and puerperae after 6 months of home use of paraprobiotics. A total of 30 pregnant women were enrolled and divided into two groups: the test group, who had to use a paraprobiotic-based toothpaste (Biorepair Peribioma Pro, Coswell S.p.A., Funo di Argelato, BO, Italy) and mousse (Mousse Mouthwash Biorepair Peribioma, Coswell S.p.A.) twice a day, and the control group, who had to use only the paraprobiotic-based toothpaste. The time frames of the study were: 1 month (T1), 3 months (T2) and 6 months (T3), and data were collected during pregnancy and in the period immediately following delivery. The following indices were evaluated at T0, T1, T2 and T3: clinical attachment loss (CAL), probing pocket depth (PPD), bleeding on probing (BOP), plaque control record (PCR), modified marginal gingival index (mMGI), papillary marginal gingival index (PMGI) and recessions (R). All data were subjected to statistical analysis. PCR decreased significantly from T0 to T1 in the control group and from T0 to T2 and from T0 to T3 in the test group. BOP tended to decrease in both groups, but a significant reduction was observed only in the test group. CAL, PPD, PMGI and mMGI tended to decrease gradually in both groups without significant differences between or within groups. The combination of the paraprobiotic-based toothpaste and the paraprobiotic-based mousse significantly reduced BoP and plaque control over time, although there were no significant differences with the use of the paraprobiotic-based toothpaste alone. In addition, the combination of the two products promoted a trend towards the better stabilization of recessions.

The Prevalence of Smokeless Tobacco Consumption and Its Effects on Gingival and Periodontal Health Among the Adults in the Emirates of Sharjah, UAE - A Cross-Sectional Study

Introduction

Smokeless tobacco (SLT) has been linked with various oral signs and symptoms, such as oral mucosal lesions and gingival and periodontal effects. However, there is limited research on the prevalence of SLT use and its impact on gingival and periodontal health in the adult population of the Emirates of Sharjah.

Aim

To assess the prevalence of SLT consumption and its effects on gingival and periodontal health in the adult population of the Emirates of Sharjah.

Methods

The study evaluated 171 dentate patients aged 18-77 years who use SLT or are nonsmokers. Data were collected through a questionnaire on SLT use and periodontal health assessed using plaque index, gingival index (GI), attachment score, and gingival recession (GR). Statistical analysis was done using SPSS 27.0 version.

Results

Among 390 screened participants, 28 subjects (21 males and 7 females) were SLT users with prevalence of 7.18%. No significant differences were found in plaque index, GI, or periodontal pocket depth. However, SLT users had significantly higher clinical attachment loss scores (mean 4.01 mm, SD 0.35) compared to non-users (mean 1.49 mm, SD 1.12). Significant differences were also observed in GR.

Conclusions

This study provides insights into the prevalence and impact of SLT use on periodontal and gingival health in UAE adults. SLT usage is associated with a higher risk of periodontitis and gingivitis, indicating the need for awareness and intervention. Further research is required to validate results and consider confounding factors.

Assessment of Clinical and Patient-Centered Outcomes in Nonsurgical Periodontal Therapy

Aim  The study was conducted to assess the clinical and patient-centered outcomes among the patients who had undergone nonsurgical periodontal therapy (NSPT). Methodology The participants for this study were 40 individuals with generalized chronic periodontitis. Numerous clinical parameters including clinical attachment level (CAL), probing pocket depth (PPD), plaque index (PI), and gingival index (GI) were evaluated along with the administration of a customized questionnaire before and after three months of therapy to evaluate patient-centered outcomes. Results Clinical parameters showed significant (p < 0.05) improvement post-NSPT. There was 100% satisfaction in few patient-centered outcomes such as bleeding gums, bad breath, food entrapment, and mobility. Conclusion A significant improvement in the clinical parameters does not guarantee improvement in patient-centered outcomes. Achieving the improvement in patient-centered outcomes can improve the overall quality of life (QOL), marking this a holistic treatment.

Lacticaseibacillus rhamnosus GG Improves Periodontal Bone Repair via Gut-Blood Axis in Hyperlipidemia

Periodontal bone regeneration remains a clinical challenge, and hyperlipidemia can aggravate alveolar bone resorption. Probiotics have recently been reported to improve bone mass. We aimed to determine the role of Lacticaseibacillus rhamnosus GG (LGG) in periodontal bone regeneration improvement within the context of periodontitis with hyperlipidemia. A Sprague Dawley rat model for periodontitis, hyperlipidemia, and periodontal fenestration defect was constructed (n = 36) and administered LGG gavage for 6 wk (the rats were subsequently sacrificed). Fecal microbiota from donor rats 3 wk after LGG gavage was transplanted into recipient rats to evaluate the role of LGG-modulated gut microbiota in periodontal bone regeneration. Regenerated bone mass was detected using micro-computerized tomography and hematoxylin and eosin stain. Gut microbiota was analyzed using 16S ribosomal RNA sequencing. Serum metabolites were detected by liquid chromatography-mass spectrometry (6 wk after LGG gavage). The pro-osteogenic effects of screened serum metabolite were verified in vitro on bone marrow mesenchymal stem cells (BMMSCs). We found that the bone mineral density, bone volume (BV), trabecular bone volume fraction (BV/TV), and trabecular thickness of the regenerated periodontal bone increased after LGG gavage (P < 0.05) but had little effect on oral flora. After LGG gavage, Staphylococcus, Corynebacterium, and Collinsella in the gut of donors were significantly changed, and these differences were maintained in recipients, who also showed increased trabecular thickness of the regenerated periodontal bone (P < 0.05). These key genera were correlated with BV/TV and BV (P < 0.05). In addition, LGG gavage significantly regulated bone-related blood metabolites, of which selenomethionine promoted BMMSC osteogenesis. Notably, selenomethionine was associated with key gut genera (P < 0.05). Collectively, LGG improved periodontal bone regeneration in the context of periodontitis with hyperlipidemia by modulating gut microbiota and increasing pro-osteogenic metabolites in the blood. These results reveal new insights into the use of probiotics to promote periodontal bone regeneration via the gut-blood-bone axis.

Influence of type 2 diabetes on immunohistochemical detection of TRAF6, cFos and NFATC1 in the gingiva in cases of chronic periodontitis

Type 2 diabetes (T2D) and chronic periodontitis (CP) are common diseases worldwide. Although T2D increases the severity of CP and alveolar bone loss, the mechanism of this is not well understood. We investigated using immunohistochemistry the expression of three osteoclast proteins, TRAF6, cFos and NFATc1, in gingival tissues. Gingival tissues were obtained from three groups: HC group, healthy controls; CP group, patients with CP; T2D + CP group, patients with both T2D and CP. Strong immunostaining for TRAF6, cFos and NFATc1 was observed in the gingival epithelium as well as in inflammatory cells in the CP and T2D + CP groups. Immunostaining was most intense in the T2D + CP group. We found strong up-regulation of TRAF6, cFos and NFATC1 in gingiva tissue of subjects with both T2D and CP, which corroborates our hypothesis that T2D potentiates osteoclastogenesis in CP.

Correlation of Serum and Gingival Crevicular Fluid Levels of Caspase-3 and Milk Fat Globule-Epidermal Growth Factor 8 on Gingival Health

AIM

This study aimed to estimate and correlate the serum and gingival crevicular fluid (GCF) levels of caspase-3 and milk fat globule-epidermal growth factor 8 (MFG-E8) in healthy, gingivitis and generalised chronic periodontitis subjects.

MATERIALS AND METHODS

A total of 24 subjects were selected and divided into three groups. After recording the periodontal parameters (plaque index (PI), modified gingival index (MGI), probing depth (PD) and clinical attachment level (CAL)), the serum and GCF samples were collected and the levels of caspase-3 and MFG-E8 were estimated using enzyme-linked immunoassay (ELISA).

RESULTS

The mean values of PI, MGI, PD and CALs were significantly higher in group III when compared to group II and group I. The mean value of serum and GCF caspase-3 increased with increasing disease severity, whereas the mean serum and GCF values of MFG-E8 decreased with increasing severity of disease. Spearman's correlation showed a strong positive correlation between the serum and GCF levels of caspase-3 and periodontal parameters, whereas serum and GCF levels of MFG-E8 showed a strong negative correlation with the periodontal parameters.

CONCLUSION

The findings of this study are suggestive that the serum and GCF levels of caspase-3 and MFG-E8 could serve as a potential biomarker for the role of apoptosis in periodontal disease. However, further studies are required to explore the mechanism and understand the relationship between these apoptotic markers and periodontitis.

Decoding the role of long non-coding RNAs in periodontitis: A comprehensive review

Periodontitis is an inflammatory disease characterized by the pathological loss of alveolar bone and the adjacent periodontal ligament. It is considered a disease that imposes a substantial health burden, with an incidence rate of 20-50%. The etiology of periodontitis is multifactorial, with genetic factors accounting for approximately half of severe cases. Studies have revealed that long non-coding RNAs (lncRNAs) play a pivotal role in periodontitis pathogenesis. Accumulating evidence suggests that lncRNAs have distinct regulatory mechanisms, enabling them to control numerous vital processes in periodontal cells, including osteogenic differentiation, inflammation, proliferation, apoptosis, and autophagy. In this review, we summarize the diverse roles of lncRNAs in the pathogenesis of periodontitis, shedding light on the underlying mechanisms of disease development. By highlighting the potential of lncRNAs as biomarkers and therapeutic targets, this review offers a new perspective on the diagnosis and treatment of periodontitis, paving the way for further investigation into the field of lncRNA-based therapeutics.

Emerging role of photodynamic therapy as an adjunct to nonsurgical periodontal therapy on periodontal status and glycemic control in patients with type 2 diabetes: A clinical study

Background

Periodontal disease is considered to be the sixth most common complication of diabetes mellitus (DM). Antibiotics (systemic and local) enhance the outcome of conventional mechanical debridement but frequent use of antimicrobials may develop resistance to microorganisms. To overcome this complicacy, the current study assessed the effectiveness of photodynamic therapy (PDT) in chronic periodontitis patients with type 2 diabetes when used as a combination therapy to standard periodontal therapy by assessing the various clinical and glycemic parameters.

Materials and Methods

A total of 16 known cases of chronic Periodontitis patients who were suffering from type 2 DM were allocated into two groups. The test group (n = 8) was treated with standard scaling and root planing (SRP) along with PDT while the control group was treated with SRP alone. Various clinical parameters assessed were plaque index, gingival index, pocket probing depth, clinical attachment level, and Glycated hemoglobin level at baseline and 90 days after therapy.

Results

At the end of the study, both the groups showed improvements with regard to all clinical and glycemic parameters compared to baseline. However, the test group presented statistically significant favorable results (all P < 0.05).

Conclusion

Conventional periodontal treatment aided with PDT proved to be a beneficial therapeutic measure and effective alternative in patients with chronic periodontitis with diabetes when compared with standard periodontal therapy alone.

Extracellular Release of Citrullinated Vimentin Directly Acts on Osteoclasts to Promote Bone Resorption in a Mouse Model of Periodontitis

Elevated osteoclast (OC)-mediated bone resorption, a common pathological feature between periodontitis and rheumatoid arthritis (RA), implicates a possible mutually shared pathogenesis. The autoantibody to citrullinated vimentin (CV), a representative biomarker of RA, is reported to promote osteoclastogenesis (OC-genesis). However, its effect on OC-genesis in the context of periodontitis remains to be elucidated. In an in vitro experiment, the addition of exogenous CV upregulated the development of Tartrate-resistant acid phosphatase (TRAP)-positive multinuclear OCs from mouse bone marrow cells and increased the formation of resorption pits. However, Cl-amidine, an irreversible pan-peptidyl arginine deiminase (PAD) inhibitor, suppressed the production and secretion of CV from RANKL-stimulated OC precursors, suggesting that the citrullination of vimentin occurs in OC precursors. On the other hand, the anti-vimentin neutralizing antibody suppressed in vitro Receptor activator of nuclear factor kappa-Β ligand (RANKL)-induced OC-genesis. The CV-induced upregulation of OC-genesis was abrogated by the Protein kinase C (PKC)-δ inhibitor Rottlerin, accompanied by the downmodulation of OC-genesis-related genes, including Osteoclast stimulatory transmembrane protein (OC-STAMP), TRAP and Matrix Metallopeptidase 9 (MMP9) as well as extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP)-kinase phosphorylation. Elevated levels of soluble CV and vimentin-bearing mononuclear cells were found in the bone resorption lesions of periodontitis induced in mice in the absence of an anti-CV antibody. Finally, local injection of anti-vimentin neutralizing antibody suppressed the periodontal bone loss induced in mice. Collectively, these results indicated that the extracellular release of CV promoted OC-genesis and bone resorption in periodontitis.

MicroRNA-126 regulates macrophage polarization to prevent the resorption of alveolar bone in diabetic periodontitis

OBJECTIVE

This study aims to investigate the effects of microRNA-126 (miR-126) on the macrophage polarization in vitro and alveolar bone resorption in vivo.

DESIGN

The relationship between miR-126 and MEK/ERK kinase 2 (MEKK2) was confirmed by dual-luciferase reporter assay. Real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay or Western blot was used to detect the changes of miR-126, inducible nitric oxide synthase (iNOS), arginase-1 (Arg-1), tumor necrosis factor (TNF)-α, interleukin (IL)-10, MEKK2 and MEKK2-related pathways: mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) in RAW264.7 macrophages challenged with Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS) and/or high glucose and/or miR-126 mimic. In mice with diabetic periodontitis, the expressions of iNOS and Arg-1 in gingiva, and alveolar bone level were detected after miR-126 mimic injection.

RESULTS

MiR-126 could directly bind with MEKK2 3'-untranslated region (UTR). MEKK2, phosphorylation of NF-κB and MAPK signaling proteins, TNF-α and iNOS increased (P < 0.05), while miR-126, Arg-1 and IL-10 were inhibited (P < 0.05) in macrophage challenged with high glucose and/or P. gingivalis LPS, however, miR-126 mimic reversed these effects (P < 0.05). The expressions of iNOS in gingiva and alveolar bone resorption were elevated (P < 0.05), the expression of Arg-1 in gingiva decreased (P < 0.05) in mice with diabetic periodontitis, which could be inhibited by miR-126 mimic.

CONCLUSIONS

miR-126 might prevent alveolar bone resorption in diabetic periodontitis and inhibit macrophage M1 polarization via regulating MEKK2 signaling pathway.

Melatonin promoted osteogenesis of human periodontal ligament cells by regulating mitochondrial functions through the translocase of the outer mitochondrial membrane 20

BACKGROUND AND OBJECTIVE

Melatonin plays an important role in various beneficial functions, including promoting differentiation. However, effects on osteogenic differentiation, especially in human periodontal cells (hPDLCs), still remain inconclusive. Mitochondria are highly dynamic organelles that play an important role in various biological processes in cells, including energy metabolism and oxidative stress reaction. Furthermore, the translocase of the outer mitochondrial membrane 20 (TOM20) is responsible for recognizing and transporting precursor proteins. Thus, the objective of this study was to evaluate the functionality of melatonin on osteogenesis in human periodontal cells and to explore the involved mechanism of mitochondria.

METHODS

The hPDLCs were extracted and identified by flow cytometry and multilineage differentiation. We divided hPDLCs into control group, osteogenic induction group, and osteogenesis with melatonin treatment group (100, 10, and 1 μM). Then we used a specific siRNA to achieve interference of TOM20. Alizarin red and Alkaline phosphatase staining and activity assays were performed to evaluate osteogenic differentiation. Osteogenesis-related genes and proteins were measured by qPCR and western blot. Mitochondrial functions were tested using ATP, NAD+/NADH, JC-1, and Seahorse Mito Stress Test kits. Finally, TOM20 and mitochondrial dynamics-related molecules expression were also assessed by qPCR and western blot.

RESULTS

Our results showed that melatonin-treated hPDLCs had higher calcification and ALP activity as well as upregulated OCN and Runx2 expression at mRNA and protein levels, which was the most obvious in 1 μM melatonin-treated group. Meanwhile, melatonin supplement elevated intracellular ATP production and mitochondrial membrane potential by increasing mitochondrial oxidative metabolism, hence causing a lower NAD⁺ /NADH ratio. In addition, we also found that melatonin treatment raised TOM20 level and osteogenesis and mitochondrial functions were both suppressed after knocking down TOM20.

CONCLUSION

We found that melatonin promoted osteogenesis of hPDLCs and 1 μM melatonin had the most remarkable effect. Melatonin treatment can reinforce mitochondrial functions by upregulating TOM20.

Isolation and characterization of apical papilla cells from root end of human third molar and their differentiation into cementoblast cells: an in vitro study

BACKGROUND

Periodontal regeneration, treatment of periodontal-related diseases and improving the function of implants are global therapeutic challenges. The differentiation of human stem cells from apical papilla into cementoblasts may provide a strategy for periodontitis treatment. This study aimed to evaluate the differentiation of primary human stem cells apical papilla (hSCAPs) to cementoblast cells.

MATERIAL AND METHODS

SCAPs cells were isolated from human third molar and then incubated for 21 days in a differentiation microenvironment. Alkaline phosphatase (ALP) and Alizarin red S staining assays were performed to evaluate the calcium deposition and formation of hydroxyapatite in the cultured hSCAPs microenvironment. Real-time polymerase chain reaction (RT-PCR) assay was performed for cementum protein 1 (CEMP1), collagen type I (COL1), F-Spondin (SPON1), osteocalcin (OCN), and osteopontin (OPN) as specific markers of cementoblasts and their progenitors.

RESULTS

ALP phosphatase activity in day 21 of treatment demonstrated a significant increase in ALP compared to the control. Alizarin red S staining assay showed that the differentiated hSCAPs offered a great amount of calcium deposition nodules compared to the control. The increased expression level of CEMP1, OCN, OPN, COL1 and Spon1 was observed in days 7, 14 and 21 compared to the control, while greatest expression level was observed in day 21.

CONCLUSION

In conclusion, the differentiation microenviroment is convenient and useful for promoting the differentiation of hSCAPs into cementoblast.

The role of extracellular vesicles in periodontitis: pathogenesis, diagnosis, and therapy

Periodontitis is a prevalent disease and one of the leading causes of tooth loss. Biofilms are initiating factor of periodontitis, which can destroy periodontal tissue by producing virulence factors. The overactivated host immune response is the primary cause of periodontitis. The clinical examination of periodontal tissues and the patient's medical history are the mainstays of periodontitis diagnosis. However, there is a lack of molecular biomarkers that can be used to identify and predict periodontitis activity precisely. Non-surgical and surgical treatments are currently available for periodontitis, although both have drawbacks. In clinical practice, achieving the ideal therapeutic effect remains a challenge. Studies have revealed that bacteria produce extracellular vesicles (EVs) to export virulence proteins to host cells. Meanwhile, periodontal tissue cells and immune cells produce EVs that have pro- or anti-inflammatory effects. Accordingly, EVs play a critical role in the pathogenesis of periodontitis. Recent studies have also presented that the content and composition of EVs in saliva and gingival crevicular fluid (GCF) can serve as possible periodontitis diagnostic indicators. In addition, studies have indicated that stem cell EVs may encourage periodontal regeneration. In this article, we mainly review the role of EVs in the pathogenesis of periodontitis and discuss their diagnostic and therapeutic potential.

Beneficial Effects of Melatonin on Periodontitis Management: Far More Than Oral Cavity

Periodontitis as a highly prevalent chronic infection/inflammatory disease can eventually lead to tooth loss and masticatory dysfunction. It also has a negative impact on general health and largely impairs quality of life. The tissue destruction during periodontitis is mainly caused by the excessive immune-inflammatory response; hence, how to modulate the host's reaction is of profound importance for effective periodontal treatment and tissue protection. Melatonin, as an endogenous hormone exhibiting multiple biological functions such as circadian rhythm regulation, antioxidant, and anti-inflammation, has been widely used in general healthcare. Notably, the past few years have witnessed increasing evidence for the application of melatonin as an adjunctive approach in the treatment of periodontitis and periodontitis-related systemic comorbidities. The detailed underlying mechanisms and more verification from clinical practice are still lacking, however, and further investigations are highly required. Importantly, it is essential to establish standard guidelines in the near future for the clinical administration of melatonin for periodontal health and general wellbeing.

Interdisciplinary Approaches to Deal with Alzheimer's Disease-From Bench to Bedside: What Feasible Options Do Already Exist Today?

Alzheimer's disease is one of the most common neurodegenerative diseases in the western population. The incidence of this disease increases with age. Rising life expectancy and the resulting increase in the ratio of elderly in the population are likely to exacerbate socioeconomic problems. Alzheimer's disease is a multifactorial disease. In addition to amyloidogenic processing leading to plaques, and tau pathology, but also other molecular causes such as oxidative stress or inflammation play a crucial role. We summarize the molecular mechanisms leading to Alzheimer's disease and which potential interventions are known to interfere with these mechanisms, focusing on nutritional approaches and physical activity but also the beneficial effects of cognition-oriented treatments with a focus on language and communication. Interestingly, recent findings also suggest a causal link between oral conditions, such as periodontitis or edentulism, and Alzheimer's disease, raising the question of whether dental intervention in Alzheimer's patients can be beneficial as well. Unfortunately, all previous single-domain interventions have been shown to have limited benefit to patients. However, the latest studies indicate that combining these efforts into multidomain approaches may have increased preventive or therapeutic potential. Therefore, as another emphasis in this review, we provide an overview of current literature dealing with studies combining the above-mentioned approaches and discuss potential advantages compared to monotherapies. Considering current literature and intervention options, we also propose a multidomain interdisciplinary approach for the treatment of Alzheimer's disease patients that synergistically links the individual approaches. In conclusion, this review highlights the need to combine different approaches in an interdisciplinary manner, to address the future challenges of Alzheimer's disease.

Association between IL-1 Gene Polymorphisms and Stage III Grade B Periodontitis in Polish Population

Periodontitis is a chronic multifactorial inflammatory disease originating from microbial, environmental and genetic factors. The present study aimed to find an association of genetic polymorphisms at IL-1A^-889 and IL-1B⁺³⁹⁵³ loci in Polish patients with stage III grade B periodontitis and periodontally healthy subjects. Fifty patients with stage III grade B periodontitis (tests) and thirty-five periodontally healthy controls were included in the study. To determine IL-1A and IL-1B gene polymorphisms, buccal swab-derived DNA obtained by means of the GenoType PST test was used. There were no statistically significant differences regarding the prevalence of IL-1A^-889 or IL-1B⁺³⁹⁵³ alleles between groups. The frequencies of different IL-1A^-889 genotypes did not differ significantly between groups. The IL-1B⁺³⁹⁵³ C/T genotype was significantly more predominant in periodontitis patients than in controls, whereas C/C genotype prevalence was significantly lower in the test group. Complex genotypes consisting of at least one IL-1A^-889 and IL-1B⁺³⁹⁵³ T allele occurred significantly more frequently in subjects with periodontitis. Stage III grade B periodontitis may be associated with the IL-1B⁺³⁹⁵³ T allele and composite IL-1 polymorphism. Reduced susceptibility to periodontal disease was present in IL-1A^-889 and IL-1B⁺³⁹⁵³ C/C homozygotic patients.

Patients with inflammatory bowel disease have a higher chance of developing periodontitis: A systematic review and meta-analysis

Background and objective

Periodontitis affects up to one billion people worldwide, and has been proven to be associated with several systemic inflammatory conditions. This study investigates the specific relationship between two multifactorial diseases: Inflammatory bowel disease (IBD) and periodontitis. To thoroughly explore this issue, we investigated separately whether IBD patients have a higher chance of developing periodontitis, and equally, whether patients with periodontitis have a higher chance of developing IBD.

Methods

The systematic search was performed in three databases: MEDLINE, Cochrane Trials, and Embase, up to 26 October 2021. The protocol was registered in PROSPERO. All eligible studies investigating the association between IBD and periodontitis from either direction were included. The Newcastle-Ottawa Scale was used to assess the risk of bias. As a primary outcome, we investigated the prevalence of IBD and periodontitis, and calculated the odds ratio (OR). Our secondary outcomes involved comparing the clinical periodontal outcomes of IBD patients to those of IBD-free patients.

Results

The systematic search resulted in 1,715 records, 14 of which were eligible for qualitative synthesis and 8 for quantitative synthesis. On the basis of the results of the primary outcome, IBD diagnosis was associated with significantly higher odds of periodontitis: OR = 2.65 (CI: 2.09-3.36, I 2 = 0 (CI: 0-0.75)). For subgroup analysis, we investigated separately the odds in Crohn's disease (CD) patients: OR = 2.22 (CI: 1.49-3.31, I 2 = 0.05 (CI: 0-0.76)) and in ulcerative colitis (UC) patients: OR = 3.52 (CI: 2.56 to 4.83, I 2 = 0 (CI: 0-0.75)); the odds were significantly higher in all cases. Two studies investigated whether patients with periodontitis were more susceptible to IBD, and both found that periodontitis was significantly associated with the risk of subsequent UC, but not with subsequent CD. However, more studies are needed to prove an association.

Conclusion

Our analysis confirmed that IBD patients have a higher chance of developing periodontitis, and are a higher risk population in dentistry. Both dentists and gastroenterologists should be aware of this relationship and should emphasize the importance of prevention even more than in the healthy population.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021286161].

Impact of Oral Mesenchymal Stem Cells Applications as a Promising Therapeutic Target in the Therapy of Periodontal Disease

Periodontal disease is a chronic inflammatory condition affecting about 20-50% of people, worldwide, and manifesting clinically through the detection of gingival inflammation, clinical attachment loss, radiographically assessed resorption of alveolar bone, gingival bleeding upon probing, teeth mobility and their potential loss at advanced stages. It is characterized by a multifactorial etiology, including an imbalance of the oral microbiota, mechanical stress and systemic diseases such as diabetes mellitus. The current standard treatments for periodontitis include eliminating the microbial pathogens and applying biomaterials to treat the bone defects. However, periodontal tissue regeneration via a process consistent with the natural tissue formation process has not yet been achieved. Developmental biology studies state that periodontal tissue is composed of neural crest-derived ectomesenchyme. The aim of this review is to discuss the clinical utility of stem cells in periodontal regeneration by reviewing the relevant literature that assesses the periodontal-regenerative potential of stem cells.

Periodontitis-related salivary microbiota aggravates Alzheimer's disease via gut-brain axis crosstalk

The oral cavity is the initial chamber of digestive tract; the saliva swallowed daily contains an estimated 1.5 × 10¹² oral bacteria. Increasing evidence indicates that periodontal pathogens and subsequent inflammatory responses to them contribute to the pathogenesis of Alzheimer's disease (AD). The intestine and central nervous system jointly engage in crosstalk; microbiota-mediated immunity significantly impacts AD via the gut-brain axis. However, the exact mechanism linking periodontitis to AD remains unclear. In this study, we explored the influence of periodontitis-related salivary microbiota on AD based on the gut-brain crosstalk in APP^swe/PS1^ΔE9 (PAP) transgenic mice. Saliva samples were collected from patients with periodontitis and healthy individuals. The salivary microbiota was gavaged into PAP mice for two months. Continuous gavage of periodontitis-related salivary microbiota in PAP mice impaired cognitive function and increased β-amyloid accumulation and neuroinflammation. Moreover, these AD-related pathologies were consistent with gut microbial dysbiosis, intestinal pro-inflammatory responses, intestinal barrier impairment, and subsequent exacerbation of systemic inflammation, suggesting that the periodontitis-related salivary microbiota may aggravate AD pathogenesis through crosstalk of the gut-brain axis. In this study, we demonstrated that periodontitis might participate in the pathogenesis of AD by swallowing salivary microbiota, verifying the role of periodontitis in AD progression and providing a novel perspective on the etiology and intervention strategies of AD.

C, Venkata RKS, Penmetsa GS, Koneru S, Pasupuleti S. Estimation of Salivary Neopterin Levels in Aggressive and Chronic Periodontitis After Nonsurgical Periodontal Therapy: A Cohort Study

Aim:

Neopterin is a marker associated with cell-mediated immunity produced by interferon-Ɣ-stimulated macrophages. The levels of neopterin in body fluids are elevated in infections, autoimmune diseases, malignancies, and allograft rejections. Recently, it was shown to be associated with the initiation and progression of periodontal disease. This investigation was designed to explore the use of salivary neopterin in predicting the outcome of nonsurgical periodontal therapy (NSPT) in aggressive and chronic periodontitis patients.

Materials and Methods:

This case-control study with stratified sampling comprised 45 subjects divided into three groups: a control group of 15 periodontally healthy participants, a test Group A of 15 participants with chronic periodontitis, and a test Group B of 15 participants with aggressive periodontitis. Periodontal parameters, including plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL), were recorded at baseline and three months after scaling and root planing (SRP). An enzyme-linked immunosorbent assay (ELISA) analysis was performed to measure neopterin levels in saliva in study groups before and after SRP. Kruskal–Wallis analysis of variance and Mann–Whitney U tests were done for intra- and intergroup comparisons. The correlation between salivary neopterin levels with clinical parameters was done by Karl Pearson’s correlation coefficient.

Results:

Baseline salivary neopterin levels were least in the control group (5 62 nmol/L), higher in test Group A (9.30 nmol/L), and highest in test Group B (9.76 nmol/L). Three months after SRP, there was a significant reduction in all the clinical parameters, and the reduction in mean salivary neopterin levels were 2.79 and 2.57 in test Group A and test Group B, respectively; the difference was not statistically significant.

Conclusion:

Salivary neopterin levels have the potential to be utilized as a diagnostic tool for detecting the presence, activity of the disease, and the course of the lesions. It cannot, however, be utilized to distinguish between chronic and aggressive periodontitis.

Gene Correlation Network Analysis to Identify Biomarkers of Peri-Implantitis

Background and Objectives: The histopathological and clinical conditions for transforming peri-implant mucositis into peri-implantitis (PI) are not fully clarified. We aim to uncover molecular mechanisms and new potential biomarkers of PI. Materials and Methods: Raw GSE33774 and GSE57631 datasets were obtained from the Gene Expression Omnibus (GEO) database. The linear models for microarray data (LIMMA) package in R software completes differentially expressed genes (DEGs). We conducted a weighted gene co-expression network analysis (WGCNA) on the top 25% of altered genes and identified the key modules associated with the clinical features of PI. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using the R software. We constructed a protein–protein interaction (PPI) network through the STRING database. After that we used Cytohubba plug-ins of Cytoscape to screen out the potential hub genes, which were subsequently verified via receiver operating characteristic (ROC) curves in another dataset, GSE178351, and revalidation of genes through the DisGeNET database. Results: We discovered 632 DEGs (570 upregulated genes and 62 downregulated genes). A total of eight modules were screened by WGCNA, among which the turquoise module was most correlated with PI. The Cytohubba plug-ins were used for filtering hub genes, which are highly linked with PI development, from the candidate genes in the protein–protein interaction (PPI) network. Conclusions: We found five key genes from PI using WGCNA. Among them, ICAM1, CXCL1, and JUN are worthy of further study of new target genes, providing the theoretical basis for further exploration of the occurrence and development mechanism of PI.

The causal effect of life‐course adiposity on periodontitis: a mendelian randomization study

BACKGROUND

To establish whether life course adiposity, including birth weight (BW), childhood and adulthood body mass index (BMI), waist-hip ratio (WHR), and body fat percentage (BF%), has a causal influence on periodontitis.

METHODS

We used single-nucleotide polymorphisms with significant associations with life course adiposity as instrumental variables. We examined their association with periodontitis risk in a genome-wide association study involving periodontitis cases (n = 17,353) and healthy controls (n = 28,210) using a two-sample Mendelian randomization (MR) strategy. The association of life course adiposity with periodontitis risk was estimated with inverse-variance weighting with random effects. We performed sensitivity analyses using MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO), weighted median, and MR-Egger methods. We calculated the odds ratios (ORs) for one standard deviation (SD) increase per risk factor to estimate the effect on the risk of periodontitis.

RESULTS

After correction for multiple testing, there was an association between each SD increase in gene-predicted adulthood BMI with a higher periodontitis risk (OR = 1.15, 95% confidence interval [CI]: 1.06-1.23, p = 3.1 × 10^-4), with a similar influence for BF% on periodontitis risk (OR = 1.29, 95% CI: 1.12-1.49, p = 3.3 × 10^-4). No causal association was detected for gene-predicted BW, childhood BMI, or WHR with periodontitis risk.

CONCLUSION

We present new proof supporting a causal function of greater adiposity, especially high BMI and BF%, being associated with higher periodontitis risk. We recommend that future studies focus on periodontitis from a life course perspective.

Evaluation of Common Factors of Periodontitis and Cardiovascular Disease in Patients with the Acute Coronary Syndrome

Periodontitis is a multifactorial disease causing inflammatory destruction of supporting structures of the dentition and eventually leading to its loss. This study was designed to evaluate common risk factors for periodontitis and acute coronary syndrome in the study population and demonstrate the systemic impact of periodontitis on the occurrence of acute coronary syndrome. A total of 160 patients (35 female and 125 male) were enrolled in the study. Considering the age range, the largest group of patients (118 patients) was between 55 and 65 years, which accounted for 73.8% of the total study population. There were 35 patients (21.9%) in the age group of 45 to 54 years, while the youngest age group of 35 to 44 years had as many as seven patients. Medical history and physical examination, including periodontal status, were performed. API, PD, CAL, and CPITN were evaluated. Common risk factors for periodontitis and acute coronary syndrome were assessed. The study assessed risk factors such as hypertension, diabetes, dyslipidemia, general health, smoking, height, weight, and hip circumference. In light of the above-described etiopathogenesis of atherosclerotic disease and its association with periodontal disease, it is important to emphasize preventing and treating periodontitis, especially in patients in the so-called high-risk group for cardiovascular disease. Dentists' introduction of an appropriate prophylactic and therapeutic plan may constitute both primary and secondary prevention of cardiovascular diseases.

Dental follicle cells derived small extracellular vesicles inhibit pathogenicity of Porphyromonas gingivalis

OBJECTIVE

It aims to explore the effect of dental follicle cells derived small extracellular vesicles (D-sEV) with or without lipopolysaccharides (LPS) pretreating on the pathogenicity of Porphyromonas gingivalis (P. gingivalis).

METHODS

The antibacterial effects of D-sEV were evaluated by measuring the growth, biofilm formation, gingipains and type IX secretion system (T9SS) expression of P. gingivalis. And the influence of D-sEV on P. gingivalis adhesion, invasion, cytotoxicity, and host immune response was examined in gingival epithelial cells (GECs). Then P. gingivalis treated with D-sEV was applied to investigate the pathogenicity in experimental periodontitis of mice.

RESULTS

It showed that both D-sEV and P. gingivalis LPS pretreated D-sEV (L-D-sEV) could target P. gingivalis, inhibit their growth and biofilm formation, and hinder the attachment and invasion in GECs, therefore remarkably decreasing P. gingivalis cytotoxicity and the expression of IL-1β and IL-6 in GECs. In addition, they significantly reduced the expression of P. gingivalis virulence factors (gingipains and T9SS). In vivo, it showed that the bacteria in the gingiva were significantly decreased after sEV treatment. Meanwhile, less bone loss and fewer inflammatory cells infiltration and osteoclast formation in D-sEV and L-D-sEV groups.

CONCLUSION

Both D-sEV and L-D-sEV were proven to inhibit the pathogenicity of P.gingivalis and thus prevented the development of periodontitis.

Effect of Non-surgical Periodontal Therapy on Salivary Melatonin Levels

Objective: Melatonin, a hormone secreted predominantly by pineal gland in a circadian manner, has antioxidant and anti-inflammatory effects. The current research is conducted to explore the influence of non-surgical periodontal therapy (NSPT) on levels of salivary melatonin in subjects with gingivitis and periodontitis. Methods: Sixty systemically healthy participants were included in this study; the groups are as follows: gingivitis (G), chronic periodontitis (CP), generalized aggressive periodontitis (GAP) and periodontally healthy (H). NSPT was applied to G group patients for 2 sessions, to CP and GAP group patients for 4 sessions. Plaque and gingival indices, probing depth (PD), bleeding on probing (BOP), and clinical attachment level (CAL) were documented at baseline and 3 months post – treatment and early morning salivary samples were collected. ELISA was used to detect melatonin levels in saliva. Pittsburgh Sleep Quality Index (PSQI) questionnaire was performed to evaluate of sleep quality of patients. Results: At baseline, significant difference in gingival index, PD, BOP and CAL values was detected among all groups (p

Polymorphisms in Genes Involved in Inflammation and Periodontitis: A Narrative Review

Current evidence pinpoints that the variability in periodontitis traits in humans may be attributable to genetic factors. Different allelic variants can result in alterations in tissue structure, antibody responses and inflammatory mediators. Consequently, genetic variations may act as protective or risk factors for periodontal diseases. A number of features of the inflammatory and immune response that seem to play a role in the development of periodontitis have a clearly established genetic basis. Identifying genes that contribute to the pathogenesis of periodontitis may be utilized for risk assessment in both aggressive and chronic periodontitis. The aim of this narrative review is to summarize the role of polymorphisms in genes involved in inflammation and periodontitis, including cellular receptors, tissue compatibility antigens, antibodies and cytokines.

The rationale and potential for using Lactobacillus in the management of periodontitis

Periodontitis refers to a wide range of the inflammatory conditions of supporting dental structures. For some patients with periodontitis, antibacterial agents are needed as an adjuvant to mechanical debridement treatments and oral hygiene maintenance. However, the widespread use of broad-spectrum antibiotics for the prophylaxis and treatment of periodontal infections results in the emergence of resistant pathogens. Therefore, probiotics have become markedly interesting to researchers as a potentially safe alternative to periodontal treatment and maintenance. Probiotics have been used in medicine for decades and extensively applied to the treatment of inflammatory diseases through the modulation of microbial synergy and other mechanisms. A growing amount of evidence has shown that using Lactobacillus strains for oral cavity maintenance could improve periodontal health. In this study, we reviewed studies showing proof of the inhibitory effects of Lactobacillus species on periodontal inflammation. We also explored the rationale and potential for using Lactobacillus species in the management of periodontitis.

Salivary levels of hBDs in children and adolescents with type 1 diabetes mellitus and gingivitis

OBJECTIVES

Type 1 diabetes mellitus (T1DM), a chronic autoimmune disease characterized by insulin deficiency, is related to periodontal diseases in children and adolescents. Our aim was to profile salivary human beta-defensin (hBD)-2 and hBD-3 concentrations in relation to periodontal and T1DM status in children and adolescent populations.

MATERIAL AND METHODS

Unstimulated saliva samples were collected from 66 participants including periodontally healthy T1DM patients (T1DM + C; n = 18), T1DM patients with gingivitis (T1DM + G; n = 20), systemically and periodontally healthy individuals (SH + C: n = 15), and systemically healthy gingivitis patients (SH + G; n = 13). Full mouth plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded. Salivary hBD-2 and hBD-3 concentrations were evaluated by sandwich ELISA method. A p value of < 0.05 was considered statistically significant.

RESULTS

Salivary hBD-3 concentrations were lower in T1DM groups in comparison to systemically healthy counterparts (SH + G vs. T1DM + G; p < 0.001 and SH + C vs. T1DM + C; p < 0.001). Salivary hBD-2 levels did not differ between related groups. The difference in hBD-3 concentrations between T1DM and control groups was still significant (p = 0.008) after being adjusted for PI%, BOP%, and age.

CONCLUSION

In the limits of study, T1DM patients were found to have decreased salivary hBD-3 concentrations, regardless of their gingival inflammatory status.

CLINICAL RELEVANCE

Altered salivary hBD-3 concentration can partly explain why diabetic children are more prone to periodontal diseases.

Periodontitis-Related Knowledge and Its Relationship with Oral Health Behavior among Adult Patients Seeking Professional Periodontal Care

Background: Periodontitis is a chronic inflammatory disease that not only damages the stomatognathic system, but may also adversely influence other systems and organs. Patients with low oral health literacy levels are more prone to gingivitis/periodontitis and have a more severe disease course. Methods: A written questionnaire was carried out to assess the knowledge of patients of the Outpatient Clinic of Department of Periodontal and Oral Mucosa Diseases, Medical University of Bialystok, Poland. The questions concerned knowledge regarding the causes of periodontal disease, its risk factors, and the connection between periodontal disease and general health status. To analyze the population, patients were divided according to gender, age and if they were first-time or regular outpatients. Results: Written questionnaires were completed by a total of 302 patients. In the studied population, we noted knowledge deficits, particularly related to weaker periodontal disease risk factors (stress, diabetes, osteoporosis, obesity) and the genetic factor, which is the determinant of periodontitis. The patients’ awareness of the role of plaque bacteria and the effect of smoking on the periodontium was at a relatively high level. The respondents were also aware of the impact of periodontal disease on general health as well as the role of oral hygiene in preventing the disease. At the same time, few of them (26%) used interdental brushes or an irrigator (8%). Conclusions: We demonstrated that patients have an insufficient level of knowledge related to risk factors as well as the prevention of periodontal disease. Awareness of the extent of oral health literacy among patients will help to identify key issues connected with health education interventions

Functional Impairment and Periodontitis in Rheumatoid Arthritis

Background

This study explored the association of functional impairment due to rheumatoid arthritis (RA) and RA disease activity with periodontal disease in patients with RA.

Methods

Ninety-three patients with RA were included. Their RA functional status was assessed using the Steinbrocker classification. The serum level of matrix metalloproteinase-3 (MMP-3) was used as an indicator of RA disease activity. Probing depth (PD) and clinical attachment level (CAL) were used as indicators of periodontal status. We examined the association of RA severity and MMP-3 levels with periodontal status using a generalised linear model (GLM).

Results

In a multivariate GLM, the coefficient for the mean PD was significantly positive in those with RA severity classes III or IV (reference: class I; β = 0.14; 95% confidence interval [CI], 0.03–0.25; P = .02) independent of other confounding variables. In multivariate GLM using the mean CAL as the dependent variable, the coefficient was significant in patients with high MMP-3 levels (10 ng/mL; β = 0.005; 95% CI, 0.001–0.008; P = .02).

Conclusions

Functional impairment due to RA may affect PD, and high serum levels of MMP-3 may affect CAL.

The Influence of Hyaluronic Acid Adjunctive Therapy of Periodontitis on Salivary Markers of Oxidative Stress: Randomized, Controlled Clinical Trial

Periodontitis is a common oral disease affecting the tooth-supporting tissues. Bacteria have been long viewed as the main causative factor in its development; however, many investigations have proved that aberrant immune and inflammatory response and the resulting misbalance between the damage caused by reactive oxygen species and the antioxidant capacity of tissues may be an underlying factor in disease progression that reduces healing potential. The objective of the current trial is to assess the outcomes of the addition of hyaluronic acid (HA) to standard non-surgical periodontal therapy (NST) on some major oxidative stress markers in saliva. HA-based gel designed for dental application was used and the measurements were taken after 3 months. HA adjunctive therapy had a significantly greater increase in markers with antioxidant properties as well as total antioxidant capacity compared to standard NST alone. Furthermore, clinically measured levels of gingival inflammation (bleeding on probing-BOP) and periodontal destruction (clinical attachment loss-CAL) were significantly correlated with these markers, and the correlation was negative. This investigation demonstrates that HA may indeed express antioxidant properties and improve the antioxidant capacity of periodontal tissues, thus improving the prognosis for the teeth and the results of periodontal therapy. Further investigations will be necessary to determine the duration of these effects over time.

Cinnamaldehyde protect against ligature-induced periodontitis through inhibitions of microbial accumulation and inflammatory responses of host immune cells

Cinnamaldehyde (CA), the main active ingredient of cinnamon, is proved to be a potential candidate of controlling inflammation, but few evidences are demonstrated on its role in periodontitis. The aim...