Clinical relevance of the host responses of periodontitis

Association of psoriasis and periodontitis in the north Indian population

Background

Psoriasis is a chronic, non-communicable condition of the skin with an immune-mediated etiology. Periodontitis is a chronic inflammatory disease of the tooth-supporting tissues and is now recognized as an established risk factor for various systemic diseases. The present observational study aims to assess the prevalence of periodontitis and its related indices in individuals with psoriasis and to compare them with individuals without psoriasis. A cross-sectional case-control study was performed in a hospital setting, including 200 diagnosed cases of psoriasis and 200 age- and sex-matched healthy controls.

Methods

The case group included patients diagnosed with psoriasis (defined as ICD-10 L40.0-L40.9) by a trained dermatologist. Controls included age- and sex-matched healthy individuals. After history-taking, a detailed dermatological and periodontal examination was done for all the enrolled subjects. The results were statistically analyzed using SPSS software.

Results

The study group had a significantly higher mean GI, PI, PPD and CAL in comparison to the controls. Psoriasis patients had significantly greater scores for GI and PI (1.68 ± 0.61 and 1.57 ± 0.54, respectively) as compared to controls (1.48 ± 0.56 and 1.39 ± 0.60, respectively). Periodontitis was also found to be more prevalent among the cases. Stage II and Stage III periodontitis were found in 41.0 % of cases and 30.5 % of controls, while 12.5 % of cases and 6.0 % of controls had stage IV periodontitis. This difference was statistically significant.

Conclusion

An association between psoriasis and periodontitis was found in the present study, as the individuals with psoriasis had a higher severity and prevalence of periodontitis.

Utility of gingival crevicular fluid components for periodontal diagnosis

Periodontal diseases are highly prevalent chronic diseases, and severe periodontitis creates functional and esthetic problems and decreases self-esteem for a large percentage of the older population worldwide. In many cases of periodontitis, there is no distinct tell-tale pain that motivates a patient to seek treatment, rather the signs become clinically detectable late, and typically when the disease has progressed to a problematic level for the life of the dentition. Early periodontal screening and diagnostics tools will provide early recognition of periodontal diseases and facilitate timely management of the disease to reduce tooth loss. To this goal, gingival crevicular fluid is easily sampled, can be repeatedly and non-invasively collected, and can be tested for potential biomarkers. Moreover, the site specificity of periodontal diseases enhances the usefulness of gingival crevicular fluid sampled from specific sites as a biofluid for diagnosis and longitudinal monitoring of periodontal diseases. The present review aimed to provide up-to-date information on potential diagnostic biomarkers with utility that can be assayed from gingival crevicular fluid samples, focusing on what is new and useful and providing only general historic background textually and in a tabulated format.

Microbial diagnostics in periodontal diseases

Microbial analytical methods have been instrumental in elucidating the complex microbial etiology of periodontal diseases, by shaping our understanding of subgingival community dynamics. Certain pathobionts can orchestrate the establishment of dysbiotic communities that can subvert the host immune system, triggering inflammation and tissue destruction. Yet, diagnosis and management of periodontal conditions still rely on clinical and radiographic examinations, overlooking the well-established microbial etiology. This review summarizes the chronological emergence of periodontal etiological models and the co-evolution with technological advances in microbial detection. We additionally review the microbial analytical approaches currently accessible to clinicians, highlighting their value in broadening the periodontal assessment. The epidemiological importance of obtaining culture-based antimicrobial susceptibility profiles of periodontal taxa for antibiotic resistance surveillance is also underscored, together with clinically relevant analytical approaches to guide antibiotherapy choices, when necessary. Furthermore, the importance of 16S-based community and shotgun metagenomic profiling is discussed in outlining dysbiotic microbial signatures. Because dysbiosis precedes periodontal damage, biomarker identification offers early diagnostic possibilities to forestall disease relapses during maintenance. Altogether, this review highlights the underutilized potential of clinical microbiology in periodontology, spotlighting the clinical areas most conductive to its diagnostic implementation for enhancing prevention, treatment predictability, and addressing global antibiotic resistance.

Potential diagnostic markers and therapeutic targets for periodontitis and Alzheimer's disease based on bioinformatics analysis

BACKGROUND AND OBJECTIVE

As a chronic inflammatory disease, periodontitis threatens oral health and is a risk factor for Alzheimer's disease (AD). There is growing evidence that these two diseases are closely related. However, current research is still incomplete in understanding the common genes and common mechanisms between periodontitis and AD. In this study, we aimed to identify common genes in periodontitis and AD and analyze the relationship between crucial genes and immune cells to provide new therapeutic targets for clinical treatment.

MATERIALS AND METHODS

We evaluated differentially expressed genes (DEGs) specific to periodontitis and AD. Co-expressed genes were identified by obtaining gene expression profile data from the Gene Expression Omnibus (GEO) database. Using the STRING database, protein-protein interaction (PPI) networks were constructed, and essential genes were identified. We also used four algorithms to identify critical genes and constructed regulatory networks. The association of crucial genes with immune cells and potential therapeutic effects was also assessed.

RESULTS

PDGFRB, VCAN, TIMP1, CHL1, EFEMP2, and IGFBP5 were obtained as crucial common genes. Immune infiltration analysis showed that Natural killer cells and Myeloid-derived suppressor cells were significantly differentially expressed in patients with PD and AD compared with the normal group. FOXC1 and GATA2 are important TFs for PD and AD. MiR-23a, miR-23b, miR-23a, and miR-23b were associated with AD and PD. Finally, the hub genes retrieved from the DSigDB database indicate multiple drug molecule and drug-target interactions.

CONCLUSION

This study reveals commonalities in common hub genes and immune infiltration between periodontitis and AD, and the analysis of six hub genes and immune cells may provide new insights into potential therapeutic directions for the pathogenesis of periodontitis complicated by AD.

Current paradigms in employing self-assembled structures: Drug delivery implications with improved therapeutic potential

Recent efforts have focused on developing improved drug delivery systems with enhanced therapeutic efficacy and minimal side effects. Micelles, self-assembled from amphiphilic block copolymers in aqueous solutions, have gained considerable attention for drug delivery. However, there is a need to further enhance their efficiency. These micelles offer benefits like biodegradability, biocompatibility, sustained drug release, and improved patient compliance. Yet, researchers must address stability issues and reduce toxicity. Nanoscale self-assembled structures have shown promise as efficient drug carriers, offering an alternative to conventional methods. Fine-tuning at the monomeric and molecular levels, along with structural modifications, is crucial for optimal drug release profiles. Various strategies, such as entrapping hydrophobic drugs and using polyethylene oxide diblock copolymer micelles to resist protein adsorption and cellular adhesion, protect the hydrophobic core from degradation. The polyethylene oxide corona also provides stealth properties, prolonging blood circulation for extended drug administration. Amphiphilic copolymers are attractive for drug delivery due to their adjustable properties, allowing control over micelle size and morphology. Emerging tools promise complex and multifunctional platforms. This article summarizes about the challenges as far as the use of micelles is concerned, including optimizing performance, rigorous pre-clinical and clinical research, and suggests further improvement for drug delivery efficacy.

[Teeth and oral cavity at the heart of systemic health]

Research into the interrelationships between oral and systemic diseases has been growing exponentially for over 20 years. Teeth and their supporting tissues can be affected by pathologies, particularly infectious ones, the consequences of which are felt locally in the oral cavity and at a distance in the body. Oral diseases frequently lead to the maintenance of an inflammatory state in oral bones and mucosa, which complicates the treatment of systemic inflammatory pathologies. The aim of this review is to take stock of current knowledge concerning the interrelationships that may exist between the oral environment and other organs, in both adults and children.

Factors Associated with Periodontitis in Younger Individuals: A Scoping Review

Periodontitis is a disease that affects many young adults, and if left untreated, it can have lasting and permanent effects on an individual's oral health. The purpose of this scoping review was to review the recent literature to identify factors that place young individuals at risk of stage II or III periodontitis. Using the PRISMA guidelines for scoping reviews, three databases were systematically searched for peer-reviewed human studies published in English that investigated risk factors associated with stage II and/or III periodontitis in individuals less than 40 years of age. This review excluded abstracts, literature reviews, including narrative, scoping, and systematic reviews and meta-analyses, conference proceedings, letters to the editor, and editorials. The authors then extracted data from the relevant studies using a predefined form to summarize the aims, design, results, risk factors examined, and the type and severity of periodontitis. Among a total of 2676 articles screened, only three articles met the review's inclusion criteria. Of these articles, one was a longitudinal case-control study and two were cross-sectional studies. Identified risk factors associated with stage II or III periodontitis included self-reported bleeding when brushing, low bone mineral density, being overweight, and smoking in young adults. Of note, only three studies met the inclusion criteria, suggesting a gap in the research literature.

Nanoparticle based periodontal drug delivery - A review on current trends and future perspectives

Introduction

Periodontitis is a chronic inflammatory disease, resulting due to host immune response against subgingival biofilm. Most conventional treatment protocols aim to control the subgingival biofilm by mechanical means, such as dental scaling and root planning, and frequently accompanied by antibacterial co-adjuvant therapies, including antibiotics, antiseptics, or probiotics. Local drug delivery facilitates administration of a lower dose of the drug to the target site, but at higher concentration, thereby reducing systemic adverse effects and toxicity. The present systematic review was conducted with the aim of identifying and reporting nanoparticle based periodontal drug delivery systems, with a specific focus on current trends and future perspectives in this field.

Materials & methods

Comprehensive literature search, restricted to published reports in English language between January 2000 and February 2022, was done electronically and manually. Search queries were addressed to the following electronic databases including, PubMed (MEDLINE), Science Direct (Elsevier), Cochrane Library, Web of Science (Clarivate Analytics) and Scholar (Google). Database search returned 780 results which were screened based on title, author names and publication dates, to identify 13 studies fulfilling the review criteria.

Results

Data from the 13 included studies were reviewed and tabulated, elaborating the type of nanoparticle used, drug delivered and tissues/cells/subcellular components targeted by periodontal drug delivery. While majority of the studies were conducted in vitro, there were 3 in vivo studies and 3 clinical studies. Using nanotechnology for drug delivery resulted in better inhibition of bacterial growth, inflammatory modulation favoring resolution of periodontitis and capability for early tissue regeneration.

Conclusion

Recent developments in nanotechnology have enabled targeted local delivery of drugs and anti-inflammatory biomolecules, in synergy with nanoparticles, towards periodontal pathogens, inflammatory cells and periodontal tissues. Further research evaluating clinical periodontal disease management through nanoparticle based local drug delivery drugs is highly recommended.

Association between Porphyromonas Gingivalis and systemic diseases: Focus on T cells-mediated adaptive immunity

The association between periodontal disease and systemic disease has become a research hotspot. Porphyromonas gingivalis (P. gingivalis), a crucial periodontal pathogen, affects the development of systemic diseases. The pathogenicity of P. gingivalis is largely linked to interference with the host's immunity. This review aims to discover the role of P. gingivalis in the modulation of the host's adaptive immune system through a large number of virulence factors and the manipulation of cellular immunological responses (mainly mediated by T cells). These factors may affect the cause of large numbers of systemic diseases, such as atherosclerosis, hypertension, adverse pregnancy outcomes, inflammatory bowel disease, diabetes mellitus, non-alcoholic fatty liver disease, rheumatoid arthritis, and Alzheimer's disease. The point of view of adaptive immunity may provide a new idea for treating periodontitis and related systemic diseases.

Biomarkers of Periodontitis and Its Differential DNA Methylation and Gene Expression in Immune Cells: A Systematic Review

The characteristic epigenetic profile of periodontitis found in peripheral leukocytes denotes its impact on systemic immunity. In fact, this profile not only stands for periodontitis as a low-grade inflammatory disease with systemic effects but also as an important source of potentially valuable clinical biomarkers of its systemic effects and susceptibility to other inflammatory conditions. Thus, we aimed to identify relevant genes tested as epigenetic systemic biomarkers in patients with periodontitis, based on the DNA methylation patterns and RNA expression profiles in peripheral immune cells. A detailed protocol was designed following the Preferred Reporting Items for Systematic Review and Meta-analysis -PRISMA guideline. Only cross-sectional and case-control studies that reported potential systemic biomarkers of periodontitis in peripheral immune cell types were included. DNA methylation was analyzed in leukocytes, and gene expression was in polymorphonuclear and mononuclear cells. Hypermethylation was found in TLR regulators genes: MAP3K7, MYD88, IL6R, RIPK2, FADD, IRAK1BP1, and PPARA in early stages of periodontitis, while advanced stages presented hypomethylation of these genes. TGFB1I1, VNN1, HLADRB4, and CXCL8 genes were differentially expressed in lymphocytes and monocytes of subjects with poorly controlled diabetes mellitus, dyslipidemia, and periodontitis in comparison with controls. The DAB2 gene was differentially overexpressed in periodontitis and dyslipidemia. Peripheral blood neutrophils in periodontitis showed differential expression in 163 genes. Periodontitis showed an increase in ceruloplasmin gene expression in polymorphonuclears in comparison with controls. Several genes highlight the role of the epigenetics of peripheral inflammatory cells in periodontitis that could be explored in blood as a source of biomarkers for routine testing.

Periostin regulates LPS-induced apoptosis via Nrf2/HO-1 pathway in periodontal ligament fibroblasts

OBJECTIVE

Periostin is important for the maintenance of periodontal tissue, but its role in periodontitis is controversial. This research investigated the effect of periostin in periodontitis and the underlying mechanism.

DESIGN

Mouse periodontitis models in vivo and inflammation model in vitro which were induced by Porphyromonas gingivalis lipopolysaccharide were established to evaluate periostin expression. Human periodontal ligament fibroblasts (PDLFs) were treated with lipopolysaccharide and N-acetylcysteine, fluorescence staining, flow cytometry, western blot, and qRT-PCR were used to detect reactive oxygen species (ROS), periostin expression, and apoptosis-related makers. The periostin gene was successfully transfected into PDLFs to verify the effect of periostin on apoptosis. Then, the Nrf2 inhibitor was added to clarify the mechanism.

RESULTS

Periostin expression decreased in the periodontal ligaments of mouse periodontitis models and lipopolysaccharide-induced PDLFs. Lipopolysaccharide promoted the activation of ROS and apoptosis in PDLFs, whereas N-acetylcysteine reversed this condition. Overexpression of periostin suppressed apoptosis of PDLFs and reversed the inhibitory effect of lipopolysaccharide on nuclear Nrf2 expression. Moreover, the Nrf2 inhibitor attenuated the protective effect of periostin on lipopolysaccharide-induced apoptosis.

CONCLUSIONS

Lipopolysaccharide induced apoptosis in PDLFs by inhibiting periostin expression and thus Nrf2/HO-1 pathway, indicating that periostin could be a potential therapeutic target for periodontitis.

The Emerging Regulatory Role of Circular RNAs in Periodontal Tissues and Cells

Periodontitis is a chronic complex inflammatory disease associated with a destructive host immune response to microbial dysbiosis, leading to irreversible loss of tooth-supporting tissues. Regeneration of functional periodontal soft (periodontal ligament and gingiva) and hard tissue components (cementum and alveolar bone) to replace lost tissues is the ultimate goal of periodontal treatment, but clinically predictable treatments are lacking. Similarly, the identification of biomarkers that can be used to accurately diagnose periodontitis activity is lacking. A relatively novel category of molecules found in oral tissue, circular RNAs (circRNAs) are single-stranded endogenous, long, non-coding RNA molecules, with covalently circular-closed structures without a 5' cap and a 3' tail via non-classic backsplicing. Emerging research indicates that circRNAs are tissue and disease-specific expressed and have crucial regulatory functions in various diseases. CircRNAs can function as microRNA or RNA binding sites or can regulate mRNA. In this review, we explore the biogenesis and function of circRNAs in the context of the emerging role of circRNAs in periodontitis pathogenesis and the differentiation of periodontal cells. CircMAP3K11, circCDK8, circCDR1as, circ_0062491, and circ_0095812 are associated with pathological periodontitis tissues. Furthermore, circRNAs are expressed in periodontal cells in a cell-specific manner. They can function as microRNA sponges and can form circRNA-miRNA-mRNA networks during osteogenic differentiation for periodontal-tissue (or dental pulp)-derived progenitor cells.

Adjuvant Transgingival Therapy with Visible Light Plus Water-Filtered Infrared-A (VIS + wIRA) in Periodontal Therapy-A Randomized, Controlled, Stratified, Double-Blinded Clinical Trial

The aim of this randomized, controlled, double-blinded clinical trial was to examine the additional healing effect of transgingival visible light and water-filtered infrared-A (VIS + wIRA) in the treatment of periodontitis patients compared with the standard therapy by subgingival instrumentation (SI). Therefore, forty patients with untreated periodontitis received a non-surgical periodontal treatment. Using a split-mouth study design, one quadrant of the upper jaw was randomly either exposed to VIS + wIRA four times for 20 min within two weeks in addition to SI or received only SI. Three and 6 months after intervention, clinical parameters (probing depths (PDs), clinical attachment level, bleeding on probing (BOP), furcation, tooth mobility, plaque control record, and papilla bleeding index) were re-evaluated. In the presence of PD of 4 mm and positive BOP or PD > 4 mm, SI was performed again. Moreover, the patients were asked about their discomfort using a visual analog scale from 1 to 10 for each side of the maxilla. Statistical analysis demonstrated no differences between quadrants at re-evaluation for clinical parameters (p > 0.05) after 3 and 6 months. Concerning pain perception, patients described less pain on the irradiated side (p = 0.016). In the treatment of patients with periodontitis, VIS + wIRA did not show an additional effect on the clinical outcome after 3 and 6 months. Patients described less pain on the irradiated quadrant after treatment.

Accuracy of a salivary examination kit for the screening of periodontal disease in a group medical check-up (Japanese-specific health check-up)

The purpose of the present study was to investigate the accuracy of a screening method using salivary tests to screen for periodontal disease.In total, 1888 individuals older than 30 years in 2017 and 2296 in 2018 who underwent medical check-ups for metabolic syndrome agreed to participate and simultaneously underwent a dental examination by dentists and salivary tests. Salivary occult blood, protein, and ammonia levels and white blood cell counts were evaluated in salivary tests using commercially available kits. The relationship between the results of the salivary tests and dental examination was examined and classification performance was analyzed.The prevalence of periodontal disease was 69.9% in 2017 and 66.8% in 2018. Salivary ammonia showed the highest classification performance in both years (sensitivity 83.5 and 83.1%, precision 73.0 and 69.3%, F-measure 0.779 and 0.756). Occult blood, which was assessed using a monoclonal antibody to human hemoglobin, also showed good performance (sensitivity 69.5%, precision 70.6%, F-measure 0.701). Questions regarding self-reported gingival bleeding were not sufficient to screen for periodontitis. The present results suggest that screening tests using salivary samples may detect periodontal disease in approximately 70% to 80% of subjects in a large population.Conclusion: Salivary ammonia and hemoglobin have potential as salivary markers in the screening of periodontal disease.

Correlations between the properties of saliva and metabolic syndrome: A prospective observational study

Saliva tests, which are easy to perform and non-invasive, can be used to monitor both oral disease (especially periodontal disease) and physical conditions, including metabolic syndrome (MetS). Therefore, in the present study the associations between saliva test results and MetS were investigated based on medical health check-up data for a large population. In total, 1,888 and 2,296 individuals underwent medical check-ups for MetS and simultaneous saliva tests in 2017 and 2018, respectively. In the saliva tests, the buffer capacity of saliva, salivary pH, the salivary white blood cell count, the number of cariogenic bacteria in saliva, salivary occult blood, protein, and ammonia levels were tested using a commercially available kit. The relationships between the results of the saliva tests and MetS components were examined in cross-sectional and longitudinal multivariate analyses. Significant relationships were detected between salivary protein levels and serum HbA1c levels or blood pressure levels and between the buffer capacity of saliva and serum triglyceride levels. In addition, salivary pH was increased irreversibly by impaired renal function. This study suggested that saliva tests conducted during health check-ups of large populations might be a useful screening tool for periodontal disease and MetS/MetS components.

Smoking reduces cathelicidin LL-37 and human neutrophil peptide 1-3 levels in the gingival crevicular fluid of patients with periodontitis

BACKGROUND

Antimicrobial peptides are components of innate immune response that have a key role on susceptibility and resistance of the oral cavity to diseases. This study aimed to investigate the influence of smoking on cathelicidin LL-37 and human neutrophil peptides 1 through 3 (HNP 1-3) levels in the gingival crevicular fluid (GCF) of patients with periodontitis. The relationship between levels of these peptides with the periodontal status and selected inflammatory mediators levels in smokers and non-smokers was also evaluated.

METHODS

Forty patients with periodontitis, 20 smokers and 20 non-smokers were recruited. After a full periodontal clinical assessment, GCF samples were collected from healthy (n = 5) and diseased (n = 5) sites of each patient. Peptides and inflammatory mediators in the GCF were quantitated by sandwich ELISAs and Multiplex assay, respectively.

RESULTS

Diseased sites had significantly (P <0.05) higher levels of LL-37 and lower levels of HNP 1-3 than healthy sites in both smokers and non-smokers. Diseased sites of smokers presented significantly lower levels of LL-37 and HNP 1-3 when compared with diseased sites of non-smokers. Concentration of LL-37 was directly correlated with the presence of proinflammatory mediators matrix metalloproteinase (MMP)-8 and interleukin (IL)-1β and inversely correlated with concentration of IL-10. HNP 1-3 concentration was positively correlated with IL-10 and negatively correlated with concentrations of MMP-8 and IL-1β.

CONCLUSIONS

Smoking was associated with reduced levels of LL-37 and HNP 1-3 in GCF of patients with periodontitis. LL-37 had a distinct expression pattern from HNP 1-3: LL-37 was upregulated in diseased sites, and HNP 1-3 was increased in periodontally healthy sites.1.

Periodontitis in patients with psoriasis: A systematic review and meta-analysis

Objective

The present study aimed to summarize and update the evidence regarding the association between periodontitis and psoriasis.

Methods

The present systematic review was conducted under the guidelines of Transparent Reporting of Systematic Reviews and Meta‐Analyses (PRISMA) and was recorded in the PROSPERO database, under registration number CRD42017063799. Three databases (MEDLINE, Embase, and Cochrane Library) were searched up to March 2020. Case–control or cohort studies assessing the association between periodontitis and psoriasis were identified. Quantitative synthesis was conducted with meta‐analysis.

Results

A total of 13 studies (11 case–control and two cohort studies) assessing the association between periodontitis and psoriasis were included. Of these 13 articles, 9 showed the prevalence of periodontitis or psoriasis. Therefore, meta‐analyses were conducted with data retrieved from the nine studies included. Pooled effect estimate for nine studies showed that patients with periodontitis associated with a higher risk of psoriasis with a pooled OR of 2.87 (95% CI, 1.75–4.69).

Conclusions

This systematic review demonstrated a positive association between periodontitis and psoriasis; however, a causal relationship cannot be established. Due to the weak evidence, caution should be taken when interpreting the results regarding periodontal parameters. Well‐designed prospective studies are necessary to evaluate interactions between both diseases.

Influence of psychological stress on non-surgical periodontal treatment outcomes in patients with severe chronic periodontitis

BACKGROUND

The aim of this study was to evaluate the influence of psychological stress on non-surgical periodontal treatment (SRP) outcomes in patients with severe chronic periodontitis (stage 3/4 generalized periodontitis) at 6 months in the French population.

METHODS

Patients diagnosed with severe generalized chronic periodontitis (periodontitis stage 3/4) were included in this study. At baseline, psychological status was evaluated by self-administered questionnaire (Depression Anxiety Stress Scale 42 [DASS-42] and Toulouse coping scale [TCS]). Plasma levels of cortisol and chromogranin-A were determined. Patients were then managed by oral hygiene instructions, scaling and root planing of sites with PD >3 mm and followed at 3 and 6 months. Quantitative and qualitative variables were described and interactions were determined by linear and logistic regressions.

RESULTS

Seventy-one patients were included in this study and 54 were followed up to 6 months. An average probing depth (PD) reduction of 0.73 ± 0.11 mm and decrease of diseased sites (PD >3 mm) were measured at 6 months illustrating SRP efficacy. Multivariable analysis showed that increased DASS-stress score was associated to worsened SRP outcomes in terms of bleeding on probing (BOP) (OR = 1.02, P <0.05) and mean PD (P <0.05) reduction. An increase of DASS-depression score negatively influenced PD >5 mm (OR = 1.06, P <0.05), PD >7 mm (OR = 1.17, P <0.01), CAL >5 mm (OR = 1.03, P <0.05), and CAL >7 mm (OR = 1.07, P <0.05) reduction. Negative coping strategies were also associated with worsened SRP outcomes.

CONCLUSIONS

Patients with increased stress, anxiety, and depression scores as well as those exhibiting negative coping strategies demonstrate worsened SRP outcomes. DASS-42 and TCS were useful to determine psychological status and their use could be incorporated to assess treatment prognosis.

Distinct Signaling Pathways Between Human Macrophages and Primary Gingival Epithelial Cells by Aggregatibacter actinomycetemcomitans

In aggressive periodontitis, the dysbiotic microbial community in the subgingival crevice, which is abundant in Aggregatibacter actinomycetemcomitans, interacts with extra- and intracellular receptors of host cells, leading to exacerbated inflammation and subsequent tissue destruction. Our goal was to understand the innate immune interactions of A. actinomycetemcomitans with macrophages and human gingival epithelial cells (HGECs) on the signaling cascade involved in inflammasome and inflammatory responses. U937 macrophages and HGECs were co-cultured with A. actinomycetemcomitans strain Y4 and key signaling pathways were analyzed using real-time PCR, Western blotting and cytokine production by ELISA. A. actinomycetemcomitans infection upregulated the transcription of TLR2, TLR4, NOD2 and NLRP3 in U937 macrophages, but not in HGECs. Transcription of IL-1β and IL-18 was upregulated in macrophages and HGECs after 1 h interaction with A. actinomycetemcomitans, but positive regulation persisted only in macrophages, resulting in the presence of IL-1β in macrophage supernatant. Immunoblot data revealed that A. actinomycetemcomitans induced the phosphorylation of AKT and ERK1/2, possibly leading to activation of the NF-κB pathway in macrophages. On the other hand, HGEC signaling induced by A. actinomycetemcomitans was distinct, since AKT and 4EBP1 were phosphorylated after stimulation with A. actinomycetemcomitans, whereas ERK1/2 was not. Furthermore, A. actinomycetemcomitans was able to induce the cleavage of caspase-1 in U937 macrophages in an NRLP3-dependent pathway. Differences in host cell responses, such as those seen between HGECs and macrophages, suggested that survival of A. actinomycetemcomitans in periodontal tissues may be favored by its ability to differentially activate host cells.

DEFB4A Promoter Polymorphism Is Associated with Chronic Periodontitis: A Case-Control Study

Background: Human β-defensin-2 is an antimicrobial peptide with antibiotic properties secreted by the oral cavity to protect the host against microbial attack. The inter-individual differences in defensin expression profiles due to genetic variation might be partly responsible for differences in disease susceptibility. Aims: The objective of this study was to examine whether variation in the human β-defensin-2 gene (DEFB4A) is associated with chronic periodontitis (CP). Materials and Methods: This case-control study used Sanger sequencing to analyze two promoter polymorphisms of the DEFB4A gene with potential functional consequences using DNA samples collected from 200 unrelated individuals. Results: The DEFB4A rs1339258595 promoter polymorphism is associated with CP risk and clinical attachment level (CAL) but the rs3762040 polymorphism is not. Carriers of the T allele (rs1339258595) were approximately three times less likely to develop periodontitis compared with noncarriers (p = 0.0004, odds ratio = 0.35). Consistent with a protective role, the carriers of T allele had a lower CAL compared with the wild-type (G) allele. Moreover, the wild-type diplotype (GGGG) had a significantly higher risk of tooth loss compared with other diplotypes (p = 0.016). Conclusion: This study demonstrates that genetic variation in the promoter region of DEFB4A likely affects resistance to periodontal infection and might be a potential marker for CP risk and severity.

Heterogeneity of human serum antibody responses to P. gingivalis in periodontitis: Effects of age, race/ethnicity, and sex

Aging humans display an increased prevalence and severity of periodontitis, although the mechanisms underlying these findings remain poorly understood. This report examined antigenic diversity of P. gingivalis related to disease presence and patient demographics. Serum IgG antibody to P. gingivalis strains ATCC33277, FDC381, W50 (ATCC53978), W83, A7A1-28 (ATCC53977) and A7436 was measured in 426 participants [periodontally healthy (n = 61), gingivitis (N = 66) or various levels of periodontitis (N = 299)]. We hypothesized that antigenic diversity in P. gingivalis could contribute to a lack of "immunity" in the chronic infections of periodontal disease. Across the strains, the antibody levels in the oldest age group were lower than in the youngest groups, and severe periodontitis patients did not show higher antibody with aging. While 80 % of the periodontitis patients in any age group showed an elevated response to at least one of the P. gingivalis strains, the patterns of individual responses in the older group were also substantially different than the other age groups. Significantly greater numbers of older patients showed strain-specific antibody profiles to only 1 strain. The findings support that P. gingivalis may demonstrate antigenic diversity/drift within patients and could be one factor to help explain the inefficiency/ineffectiveness of the adaptive immune response in managing the infection.

Periodontitis: a newly identified comorbidity in psoriasis and psoriatic arthritis

Introduction: Psoriasis is a chronic autoimmune skin disease with strong genetic background and environmental triggers. Patients with psoriasis and psoriatic arthritis are at greater risk of developing other chronic and potentially severe comorbidities, such as psoriatic arthritis, hyperlipidemia, type 2 diabetes mellitus, obesity, metabolic syndrome, cardiovascular diseases or depression. Recently, accumulating epidemiologic, genetic and pathogenetic evidence indicates that psoriasis is also associated with periodontitis, a chronic progressive inflammatory disease, which may result in tooth loss without early and adequate therapy.Areas covered: In this review article we summarize and discuss in detail the available epidemiologic, genetic, microbiological and immunological links between psoriasis and periodontitis.Expert opinion: Periodontitis, via the immunomodulatory effect of the oral microbiota, may play both a direct and indirect role in the development or exacerbation of psoriasis, and may influence the efficacy of antipsoriatic therapy. These new findings indicate a need for increased awareness, early recognition and focus on prevention of periodontitis for patients with psoriasis.

Effects of non-surgical periodontal therapy on inflammatory markers of psoriasis: A randomized controlled trial

AIM

The purpose of this randomized controlled clinical study was to evaluate the effect of non-surgical mechanical periodontal therapy on the inflammatory status and severity of psoriasis in subjects with psoriasis.

MATERIAL AND METHODS

The study population consisted of 92 periodontitis patients with psoriasis vulgaris suffering from an untreated periodontal disease. Two randomized groups were formed from these patients: immediate periodontal therapy (test group, n = 46) and delayed periodontal therapy (control group, n = 46). Periodontal clinical measures, on salivary interleukin 2, interleukin 6 and secretory immunoglobulin A levels and the Psoriasis Area and Severity Index (PASI) scores were evaluated at baseline and on the 8th week in control and test groups.

RESULTS

Eight weeks after completion of non-surgical periodontal therapy (test group) or initial examination (control group), a significant decrease was observed in interleukin 2, interleukin 6 level and in PASI score, whereas a significant increase was observed in secretory immunoglobulin A levels in the test group (p < .05).

CONCLUSION

Within the limits of this study, the results suggest that effective periodontal therapy improves the psoriasis condition in patients afflicted by both diseases.

Linkage of Periodontitis and Rheumatoid Arthritis: Current Evidence and Potential Biological Interactions

The association between rheumatoid arthritis (RA) and periodontal disease (PD) has been the focus of numerous investigations driven by their common pathological features. RA is an autoimmune disease characterized by chronic inflammation, the production of anti-citrullinated proteins antibodies (ACPA) leading to synovial joint inflammation and destruction. PD is a chronic inflammatory condition associated with a dysbiotic microbial biofilm affecting the supporting tissues around the teeth leading to the destruction of mineralized and non-mineralized connective tissues. Chronic inflammation associated with both RA and PD is similar in the predominant adaptive immune phenotype, in the imbalance between pro- and anti-inflammatory cytokines and in the role of smoking and genetic background as risk factors. Structural damage that occurs in consequence of chronic inflammation is the ultimate cause of loss of function and disability observed with the progression of RA and PD. Interestingly, the periodontal pathogen Porphyromonas gingivalis has been implicated in the generation of ACPA in RA patients, suggesting a direct biological intersection between PD and RA. However, more studies are warranted to confirm this link, elucidate potential mechanisms involved, and ascertain temporal associations between RA and PD. This review is mainly focused on recent clinical and translational research intends to discuss and provide an overview of the relationship between RA and PD, exploring the similarities in the immune-pathological aspects and the possible mechanisms linking the development and progression of both diseases. In addition, the current available treatments targeting both RA and PD were revised.

Periodontitis in individuals with liver cirrhosis: A case-control study

AIM

The aim of this study was to evaluate the association between liver cirrhosis and periodontitis.

METHODS

This case-control study included 294 individuals, 98 cases with liver cirrhosis and 196 controls. A full-mouth periodontal examination was performed and plaque index, probing depth, clinical attachment level and bleeding on probing were recorded. The association of risk variables with periodontitis was tested through univariate analysis and multivariate logistic regression, stratified by alcohol status.

RESULTS

A high prevalence of periodontitis was observed among cases (62.2%) when compared to controls (41.8%). Individuals with cirrhosis presented a chance ~2 higher of having periodontitis than controls (OR = 2.28; 95% CI 1.39-3.78; p < .001). Significant variables associated with periodontitis in the final logistic models were as follows: (a) no/occasional alcohol use model-number of teeth up 14, age ≥45-55 years, male sex and smoking; (b) moderate and intensive alcohol use models-cirrhosis, number of teeth up 14, age ≥45-55 years, male sex and smoking.

CONCLUSIONS

An important risk association between liver cirrhosis and periodontitis was observed. Additionally, the intensive alcohol use significantly increased the risk for periodontitis.

Increased Risk of Carotid Atherosclerosis in Male Patients with Chronic Periodontitis: A Nationwide Population-Based Retrospective Cohort Study

Carotid artery stenosis is a narrowing or constriction of any part of the carotid arteries, usually caused by atherosclerosis. However, no studies have specifically evaluated the association between carotid atherosclerosis (CA) and chronic periodontitis (CP). This study was to investigate the role of CP in increasing the subsequent risk of CA in the overall Taiwanese population. We carried out this retrospective cohort study, employing data derived from the National Health Insurance Research Database. A total of 72,630 patients who were newly diagnosed with CP from 2001 to 2012 were selected. For a propensity-matched control group, 72,630 healthy patients without CP were picked at random, matched according to age, sex, and index year from the general population. Cox proportional hazard regression analysis, which included sex, age, and comorbidities, was adopted to assess the hazard ratio (HR) of CA between the CP cohort and non-CP cohort. The average ages of the CP and non-CP groups were 44.02 ± 14.63 years and 44.15 ± 14.41 years, respectively. The follow up durations were 8.65 and 8.59 years for CP and non-CP groups, respectively. The results demonstrated that 305 and 284 patients with newly diagnosed CA were found in the CP cohort and non-CP cohort, respectively. There was no significant difference of developing CA in the CP cohort compared with the non-CP cohort (adjusted HR) 1.01, 95% confidence interval (CI, 0.86-1.19). However, multivariate Cox regression analysis indicated that the male group had significantly higher incidence risk of CA (log rank p = 0.046). In conclusion, this nationwide retrospective cohort study indicated that male patients with CP exhibited a significantly higher risk of CA than those without CP.

Efficacy of virginiamycin for the control of periodontal disease in calves

ABSTRACT: Periodontal diseases are multifactorial infectious processes caused by complexes of microorganisms, with damage to health, production, and animal welfare. The aim of the present study was to evaluate the efficacy of virginiamycin in the prevention and control of two early forms of periodontal disease: gingivitis and necrotizing gingivitis. Ten weaned calves, aged four to six months, were permanently kept in a single lot under the same rotational grazing regime in a newly reformed area of Panicum maximum. Five of the calves were orally administered 340mg of virginiamycin (Virginiamycin Group) daily for a period of 18 weeks, while the remaining five calves (Control Group) remained under the same food management but did not receive virginiamycin. During this period, animals underwent 18 weekly evaluations regarding periodontal health, with monitoring and recording of clinical parameters of the eight deciduous incisor teeth on the labial and lingual faces. At approximately two-week intervals, nine collections of subgingival sulcus material from five sites of the four right incisor teeth of each animal were performed and subjected to microbiological evaluation using polymerase chain reaction with primers of 25 microorganisms considered potentially pathogenic. After 1440 periodontal clinical evaluations of incisor teeth of the 10 calves, a total of 395 episodes of gingivitis were recorded, of which 267 occurred in the Control Group and 128 in the Virginiamycin Group. Similarly, 89 episodes of necrotizing gingivitis were recorded; 58 in the Control Group and 31 in the Virginiamycin Group. Comparison of between-group means found significant differences for teeth with gingivitis and necrotizing gingivitis (t test; p<0.05). The total number of teeth with gingivitis (p<0.01) and necrotizing gingivitis (p<0.01) in Control Group was significantly higher than that of gingivitis (p<0.01) and necrotizing gingivitis (p<0.05) in the Virginiamycin Group. There was a positive correlation between total occurrence of gingivitis and necrotizing gingivitis in the Virginiamycin Group by Pearson’s test. Virginiamycin had a protective effect on treated animals compared with the Control Group (OR = 0.36: CI (95%) = 0.27-0.43). In the Control Group, Actinomyces israelli (4.74%), domain Archaea (1.58%), Eikenella corrodens (1.05%), Fusobacterium nucleatum (27.37%), class Mollicutes (5.26%); Porphyromonas endodontalis(5.26%); Porphyromonas gulae(0.53%), Prevotella buccae (6.32%), Prevotella loescheii (3.68%), Prevotella nigrescens (8.42%), Prevotella oralis (1.58%), Tannerella forsythia (0.53%), and Treponema denticola (4.21%) were detected at healthy sites, and gingivitis or necrotizing gingivitis samples. In the Virginiamycin Group, A. israelli (3.41%), domain Archaea (0.98%), F. nucleatum (9.27%), class Mollicutes(4.39%), P. endodontalis (4.39%), P. gulae (0.49%), P. buccae (8.29%), P. loescheii (6.83%), P. nigrescens (15.61%), P. oralis (1.46%), Selenomonas sputigena (0.49%), T. forsythia (0.49%), and T. denticola (2.44%) were detected. In conclusion, virginiamycin administered at a dosage of 340mg/animal/day significantly reduced the occurrence of gingivitis and necrotizing gingivitis in cattle maintained on reformed pastures, and was revealed to have action against periodontal bacterial microbiota considered to be potentially pathogenic.

Multifunctional nanocarriers for the treatment of periodontitis: Immunomodulatory, antimicrobial, and regenerative strategies

Periodontitis is an inflammatory disease, in which the host immuno-inflammatory response against the dysbiotic subgingival biofilm leads to the breakdown of periodontal tissues. Most of the available treatments seem to be effective in the short-term; nevertheless, permanent periodical controls and patient compliance compromise long-term success. Different strategies have been proposed for the modulation of the host immune response as potential therapeutic tools to take a better care of most susceptible periodontitis patients, such as drug local delivery approaches. Though, maintaining an effective drug concentration for a prolonged period of time has not been achieved yet. In this context, advanced drug delivery strategies using biodegradable nanocarriers have been proposed to avoid toxicity and frequency-related problems of treatment. The versatility of distinct nanocarriers allows the improvement of their loading and release capabilities and could be potentially used for microbiological control, periodontal regeneration, and/or immunomodulation. In the present review, we revise and discuss the most frequent biodegradable nanocarrier strategies proposed for the treatment of periodontitis, including polylactic-co-glycolic acid (PLGA), chitosan, and silica-derived nanoparticles, and further suggest novel therapeutic strategies.

Periodontitis as another comorbidity associated with psoriasis: A case-control study

BACKGROUND

The association between periodontitis and immuno-mediated inflammatory diseases has been widely studied and recognized each more over the past few years. The aim of this study was to evaluate the potential association between psoriasis and periodontitis, as well as the influence of risk variables in this association.

METHODS

This case-control study included 756 individuals, 397 with psoriasis, and 359 controls. A full-mouth periodontal examination was performed, recording therefore plaque index, probing depth, clinical attachment level, and bleeding on probing. The influence of risk variables was tested by univariate analysis and multivariate logistic regression.

RESULTS

A high prevalence of periodontitis was observed among cases (46.1%) when compared to controls (33.1%). Individuals with psoriasis presented a 1.72 higher chance of having periodontitis than controls (OR = 1.72; 95% CI 1.28-2.32; p < 0.001) in the univariate analysis, but with no significance in the multivariate model. The prevalence of periodontitis increased significantly according to the severity of psoriasis [mild form (44.4%); moderate (46.3%); and advanced (47.1%)] when compared to the control group (33.1%). The final multivariate logistic model showed that the number of teeth (OR = 1.08; 95% CI 1.01-1.14; p = 0.018), smoking (OR = 1.91; 95% CI 1.19-3.07; p = 0.008), and body mass index (OR = 1.13; 95% CI 1.11-1.16; p < 0.001) remained significantly associated with the occurrence of periodontitis.

CONCLUSIONS

The prevalence of periodontitis was higher in individuals with psoriasis than in controls. Severity of psoriasis also presented a strong relationship with all periodontal clinical parameters.

Azithromycin Promotes the Osteogenic Differentiation of Human Periodontal Ligament Stem Cells after Stimulation with TNF-α

Background and Objective

This study investigated the effects and underlying mechanisms of azithromycin (AZM) treatment on the osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) after their stimulation with TNF-α in vitro. Methods. PDLSCs were isolated from periodontal ligaments from extracted teeth, and MTS assay was used to evaluate whether AZM and TNF-α had toxic effects on PDLSCs viability and proliferation. After stimulating PDLSCs with TNF-α and AZM, we analyzed alkaline phosphatase staining, alkaline phosphatase activity, and alizarin red staining to detect osteogenic differentiation. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis was performed to detect the mRNA expression of osteogenic-related genes, including RUNX2, OCN, and BSP. Western blotting was used to measure the NF-κB signaling pathway proteins p65, phosphorylated p65, IκB-α, phosphorylated IκB-α, and β-catenin as well as the apoptosis-related proteins caspase-8 and caspase-3. Annexin V assay was used to detect PDLSCs apoptosis.

Results

TNF-α stimulation of PDLSCs decreased alkaline phosphatase and alizarin red staining, alkaline phosphatase activity, and mRNA expression of RUNX2, OCN, and BSP in osteogenic-conditioned medium. AZM enhanced the osteogenic differentiation of PDLSCs that were stimulated with TNF-α. Western blot analysis showed that β-catenin, phosphorated p65, and phosphorylated IκB-α protein expression decreased in PDLSCs treated with AZM. In addition, pretreatment of PDLSCs with AZM (10 μg/ml, 20 μg/ml) prevented TNF-α-induced apoptosis by decreasing caspase-8 and caspase-3 expression.

Conclusions

Our results showed that AZM promotes PDLSCs osteogenic differentiation in an inflammatory microenvironment by inhibiting the WNT and NF-κB signaling pathways and by suppressing TNF-α-induced apoptosis. This suggests that AZM has potential as a clinical therapeutic for periodontitis.

Increased risk of periodontitis among patients with Crohn's disease: a population-based matched-cohort study

BACKGROUND

Periodontitis is a frequently cited extraintestinal manifestation of Crohn's disease (CD). Despite a plethora of investigations and a recent meta-analysis linking CD and periodontitis, no study has estimated the risk of periodontitis among CD patients with respect to a comparison group nor has any investigation analyzed the effect of CD-specific medications on the risk of periodontitis. The present cohort study compared CD patients and matched subjects without a history of inflammatory bowel disease (IBD) to estimate the effect of CD and CD-specific pharmaceutical prescriptions on the risk of developing periodontitis by leveraging a population-based dataset in Taiwan.

METHODS

We sourced 6657 CD patients and 26,628 comparison subjects without a history of IBD from the Taiwan National Health Insurance Database. Cox proportional hazards regressions were used to estimate the risk of subsequent periodontitis by CD status and pharmaceutical prescription during the follow-up period.

RESULTS

After adjusting for socioeconomic status (SES), urbanicity, selected medical co-morbidities, and CD-specific pharmaceutical prescriptions, the hazard ratio (HR) for subsequent periodontitis among patients with CD was 1.36 (95% CI = 1.25-1.48) that of comparison subjects. There was not a significant difference in risk between genders or across ages. Steroids (95% CI = 0.66-0.77) appeared to confer a protective effect and Aspirin, Plavix, and Licodin were marginally protective (95% CI = 0.76-0.95).

CONCLUSION

This is the first study to report an increased HR for subsequent periodontitis among CD patients when compared to matched comparison subjects without IBD. The protective effect of some pharmaceuticals may suggest that treatment of CD protects against periodontitis.

Effect of Lactobacillus rhamnosus and Bifidobacterium lactis on gingival health, dental plaque, and periodontopathogens in adolescents: a randomised placebo-controlled clinical trial

To determine the effect of a probiotic combination of Lactobacillus rhamnosus GG (LGG) and Bifidobacterium lactis BB-12 on the gingival health, dental plaque accumulation, and the oral carriage of four putative periodontal pathogens in healthy adolescents. 108 schoolboys, aged 13-15 years, participated in this study. They were divided into two groups: probiotics (n=54) and placebo (n=54). Both groups received two probiotic-laced or placebo lozenges twice a day during a four-week period. Plaque Index (PI) and Gingival Index (GI) were recorded at baseline and after four weeks. Salivary and plaque carriage of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum were also monitored likewise. 101 subjects completed the study. A statistically significant reduction in GI was seen in the probiotic group as compared to the placebo group (P=0.012). A reduction in PI was found for both groups, with no difference observed between the groups after intervention (P=0.819). Probiotic lozenges significantly reduced levels of A. actinomycetemcomitans and F. nucleatum in saliva and plaque (P<0.05) and levels of P. gingivalis in plaque (P<0.05), while no significant changes were found in the control group. A significant reduction (P<0.001) was also noted in the total salivary bacterial counts of the test group. The short-term daily consumption of LGG and BB-12 probiotic lozenges improved the gingival health in adolescents and decreased the microbial counts of A. actinomycetemcomitans, and P. gingivalis. Hence probiotic supplements may serve as a simple adjunct to standard oral care for promoting the oral health in adolescents.

Chronic biofilm-based infections: skewing of the immune response

Many of the deadliest bacterial diseases that plague humanity in the modern age are caused by bacterial biofilms that produce chronic infections. However, most of our knowledge of the host immune response comes from the study of planktonic pathogens. While there are similarities in the host response to planktonic and biofilm bacteria, specific immune responses toward biofilms have not been well studied; the only apparent difference is the inability to clear the bacteria allowing the biofilm infection to become chronic. In some cases, the biofilms skew T-cell response toward a balance that allows a stalemate between the host and the pathogen, in which the infection can become persistent. In this minireview, we will summarize well-known examples of this phenomena as well as some emerging studies that may indicate that this situation is much more common than initially thought.

Hypoxia-inducible transcription factors, HIF1A and HIF2A, increase in aging mucosal tissues

Hypoxia (i.e. oxygen deprivation) activates the hypoxia-signalling pathway, primarily via hypoxia-inducible transcription factors (HIF) for numerous target genes, which mediate angiogenesis, metabolism and coagulation, among other processes to try to replenish tissues with blood and oxygen. Hypoxia signalling dysregulation also commonly occurs during chronic inflammation. We sampled gingival tissues from rhesus monkeys (Macaca mulatta; 3-25 years old) and total RNA was isolated for microarray analysis. HIF1A, HIF1B and HIF2A were significantly different in healthy aged tissues, and both HIF1A and HIF3A were positively correlated with aging. Beyond these transcription factor alterations, analysis of patterns of gene expression involved in hypoxic changes in tissues showed specific increases in metabolic pathway hypoxia-inducible genes, whereas angiogenesis pathway gene changes were more variable in healthy aging tissues across the animals. With periodontitis, aging tissues showed decreases in metabolic gene expression related to carbohydrate/lipid utilization (GBE1, PGAP1, TPI1), energy metabolism and cell cycle regulation (IER3, CCNG2, PER1), with up-regulation of transcription genes and cellular proliferation genes (FOS, EGR1, MET, JMJD6) that are hypoxia-inducible. The potential clinical implications of these results are related to the epidemiological findings of increased susceptibility and expression of periodontitis with aging. More specifically the findings describe that hypoxic stress may exist in aging gingival tissues before documentation of clinical changes of periodontitis and, so, may provide an explanatory molecular risk factor for an elevated capacity of the tissues to express destructive processes in response to changes in the microbial biofilms characteristic of a more pathogenic microbial challenge.

Oral Biofilms from Symbiotic to Pathogenic Interactions and Associated Disease -Connection of Periodontitis and Rheumatic Arthritis by Peptidylarginine Deiminase

A wide range of bacterial species are harbored in the oral cavity, with the resulting complex network of interactions between the microbiome and host contributing to physiological as well as pathological conditions at both local and systemic levels. Bacterial communities inhabit the oral cavity as primary niches in a symbiotic manner and form dental biofilm in a stepwise process. However, excessive formation of biofilm in combination with a corresponding deregulated immune response leads to intra-oral diseases, such as dental caries, gingivitis, and periodontitis. Moreover, oral commensal bacteria, which are classified as so-called “pathobionts” according to a now widely accepted terminology, were recently shown to be present in extra-oral lesions with distinct bacterial species found to be involved in the onset of various pathophysiological conditions, including cancer, atherosclerosis, chronic infective endocarditis, and rheumatoid arthritis. The present review focuses on oral pathobionts as commensal and healthy members of oral biofilms that can turn into initiators of disease. We will shed light on the processes involved in dental biofilm formation and also provide an overview of the interactions of P. gingivalis, as one of the most prominent oral pathobionts, with host cells, including epithelial cells, phagocytes, and dental stem cells present in dental tissues. Notably, a previously unknown interaction of P. gingivalis bacteria with human stem cells that has impact on human immune response is discussed. In addition to this very specific interaction, the present review summarizes current knowledge regarding the immunomodulatory effect of P. gingivalis and other oral pathobionts, members of the oral microbiome, that pave the way for systemic and chronic diseases, thereby showing a link between periodontitis and rheumatoid arthritis.

The role of extracellular matrix metalloproteinase inducer glycosylation in regulating matrix metalloproteinases in periodontitis

BACKGROUND AND OBJECTIVE

Extracellular matrix metalloproteinase inducer (EMMPRIN) is a transmembrane glycoprotein that may induce activation of matrix metalloproteinases (MMPs) and lead to the destruction of periodontal tissue. The level of EMMPRIN glycosylation might be involved in this process. This study aims to investigate the role of EMMPRIN glycosylation in regulating MMP-2 and MMP-9 during the progression of periodontitis.

MATERIAL AND METHODS

Gingival tissues were collected from patients with chronic periodontitis and from patients undergoing crown-lengthening procedures (healthy gingival tissue). Tissues were used for immunohistochemistry and double immunofluorescence. A human immortalized oral epithelial cell (HIOEC) line was stably transfected by an N-acetylglucosaminyltransferase-V (GnT-V) RNA interference (RNAi) lentivirus to suppress EMMPRIN glycosylation. Gene silence efficiency was detected by western blot, quantitative real-time PCR and immunofluorescence (IF) staining. An HIOEC/human gingival fibroblast (HGF) co-culture model and an individual culture model were used in this study. After exposure of cells to Porphyromonas gingivalis lipopolysaccharide (Pg. LPS), the expression of EMMPRIN, MMP-2 and MMP-9 were assessed by western blot, quantitative real-time PCR and IF, and the secretion of MMP-2 and MMP-9 were detected by gelatin-degradation assays.

RESULTS

Compared with the periodontally healthy group, patients with periodontitis showed increased expression of EMMPRIN on the gingival epithelial cell membrane. GnT-V, a key regulator of EMMPRIN glycosylation, was co-expressed with EMMPRIN in gingival epithelial cells in patients with periodontitis. Knockdown of GnT-V reduced the level of EMMPRIN glycosylation in HIOECs. Furthermore, in the HIOEC/HGF co-culture model, stimulation with Pg. LPS (10 μg/mL, 4 hours) promoted EMMPRIN glycosylation and increased the activities of MMP-2 and MMP-9, while suppression of EMMPRIN glycosylation by GnT-V knockdown reduced the synthesis and activities of MMP-2 and MMP-9 under Pg. LPS stimulation. Moreover, the gelatin-degradation assay showed that inhibition of EMMPRIN glycosylation suppressed the Pg. LPS-induced degradation of gelatin in the co-culture model.

CONCLUSION

We conclude that EMMPRIN glycosylation participates in the regulation of MMP-2 and MMP-9 production through mediating the interaction of HIOECs and HGFs. Inhibiting EMMPRIN glycosylation can reduce the activation of MMP-2 and MMP-9 and suppress the degradation of extracellular matrix (ECM) in the HIOEC/HGF co-culture model. Therefore, this study suggests that EMMPRIN glycosylation may affect the host immune-inflammatory response by regulating MMPs in periodontitis.

Are periodontal outcomes affected by personality patterns? A 18-month follow-up study

OBJECTIVES

This research aims to study the relationship between personality traits and periodontal clinical outcomes by taking into account the level of anxiety and depression, periodontal health and oral hygiene behaviour of patients affected with gingivitis or moderate periodontitis requiring periodontal therapy.

MATERIAL AND METHODS

The periodontal data of 40 systemically healthy patients affected by gingivitis or moderate periodontitis were collected at baseline and 18 months later. The psychological variables, dental awareness and adherence intent of the patients were assessed through questionnaires, and only those patients that exhibited a higher degree of compliance were included in the study. The personality traits (cluster A: paranoid, schizoid, schizotypal; cluster B: borderline, antisocial, narcissistic, and histrionic; cluster C: avoidant, dependent, and obsessive-compulsive) and the level of anxiety and depression of the patients were assessed. Patients were instructed with oral hygiene measures and were treated with periodontal therapy.

RESULTS

Clusters A and B showed a consistent tendency for reduced levels of oral hygiene (increased full-mouth plaque score - FMPS). The results from cluster B were found to be significantly related to deep periodontal pockets at baseline. On the contrary, cluster C seemed to be linked to clinically better indices, particularly in terms of full-mouth-bleeding-score and pocket depth, both at baseline and 18 months later. The results collected from clusters B and C were directly correlated with anxiety, depression and FMPS. Moreover, anxiety was directly correlated with the patient's need for professional oral-care.

CONCLUSIONS

Personality traits appear to play a significant role in determining the therapeutic outcomes of periodontal therapy in themselves. Thus, it is ideal for several important psychological, affective or behavioural factors to be associated with various personality traits so as to orient the outcome of periodontal therapy.

Increased risk of periodontitis in patients with psoriatic disease: a nationwide population-based retrospective cohort study

Aims

Periodontitis and psoriatic disease, including psoriasis (PS) and psoriatic arthritis (PsA), share the common risk factors and co-morbidities. However, the risk of periodontitis in patients with psoriatic disease still needs further investigation. This study was a nationwide population-based retrospective cohort study assessing the risk of periodontitis from psoriatic disease exposure.

Materials and Methods

Patients with newly diagnosed psoriatic disease from 2003 to 2012 were identified from the Taiwanese National Health Insurance Research Database. The 1:4 ratio propensity score matched controls were selected from no psoriatic disease participations. The subsequent risk of periodontitis was evaluated in exposure and comparison groups. Multiple Cox proportional hazard models were used for the estimation.

Results

A total of 3,487 psoriatic disease patients and 13,948 controls were identified. Incidence rate of periodontitis was higher in patients with PsA. The adjusted hazard ratio (aHRs) for moderate/severe periodontitis were 0.85 (95% CI [0.65-1.11]) in PS group and 1.66 (95% CI [0.99-2.78]) in PsA group. The aHRs of PsA were increased over time, aHRs was changed from 0.65 (0-11 months from index date) to 1.34 (≥12 months from index date) in all types of periodontitis and from 1.09 to 1.79 in moderate/severe periodontitis group, respectively.

Conclusions

The increased risk of periodontitis was observed, especially the association between PsA and moderate/severe periodontitis. The patients with psoriatic disease should receive regular periodontal evaluation.

Nicotine Upregulates Coaggregation of Candida albicans and Streptococcus mutans

PURPOSE

Denture stomatitis is a condition of painless inflammation of denture-bearing mucosa. Reports indicate that nicotine, the major psychoactive ingredient in tobacco, increases growth of Streptococcus mutans and Candida albicans in denture biofilm. The purpose of this study was to determine the in vitro effects of nicotine on coaggregation of C. albicans with S. mutans.

MATERIAL AND METHODS

C. albicans strain ATCC 10231, S. mutans strain UA159 (ATTC 700610), and nicotine dilutions (ranging from 0 to 32 mg/ml) were used for this study. Both microorganisms were grown for 24 hours in dilutions of nicotine (0 to 32 mg/ml) made in tryptic soy broth (TSB) or TSB supplemented with 1% sucrose (TSBS; S. mutans) or yeast peptone dextrose broth (YPD; C. albicans). Suspensions of the nicotine-treated cells were prepared, mixed together and incubated for up to 24 hours to determine if there was an increase in coaggregation of nicotine-treated cells compared to the no nicotine control cells. Qualitative analysis of coaggregation was performed using a visual aggregation assay and light microscopic observation. A spectrophotometric assay was used to provide a quantitative analysis of the coaggregation.

RESULTS

The visual aggregation assay indicated a significant increase in coaggregation between C. albicans and S. mutans with increasing incubation time (0 to 24 hours) and nicotine concentrations (0 to 4 mg/ml). Microbial growth in nicotine at 4 mg/ml demonstrated a significant increase in coaggregation after 24 hours of incubation. The numbers of coaggregated S. mutans/C. albicans cells exhibited a significant increase with incubation time and nicotine concentrations when the samples were examined microscopically. More coaggregation of S. mutans and C. albicans was observed with incubation time and increased nicotine compared to the 0 mg/ml nicotine group. There was a noticeable increase of coaggregation when cells were grown in TSBS compared to TSB. Absorbance of nicotine-treated cells (0.25 to 4 mg/ml) exhibited a decrease in values compared to 0 mg/ml at 0 hours of incubation, confirming increased coaggregation.

CONCLUSION

These results demonstrated the effect of nicotine in increasing the coaggregation of S. mutans with C. albicans. Coaggregation increased with incubation time and nicotine concentration. Coaggregation was increased with S. mutans grown in TSBS compared to TSB, suggesting that growth in sucrose media leads to an increase in receptors responsible for coaggregation.

Cross-talk between clinical and host-response parameters of periodontitis in smokers

BACKGROUND AND OBJECTIVE

Periodontal diseases are a major public health concern leading to tooth loss and have also been shown to be associated with several chronic systemic diseases. Smoking is a major risk factor for the development of numerous systemic diseases, as well as periodontitis. While it is clear that smokers have a significantly enhanced risk for developing periodontitis leading to tooth loss, the population varies regarding susceptibility to disease associated with smoking. This investigation focused on identifying differences in four broad sets of variables, consisting of: (i) host-response molecules; (ii) periodontal clinical parameters; (iii) antibody responses to periodontal pathogens and oral commensal bacteria; and (iv) other variables of interest, in a population of smokers with (n = 171) and without (n = 117) periodontitis.

MATERIAL AND METHODS

Bayesian network structured learning (BNSL) techniques were used to investigate potential associations and cross-talk between the four broad sets of variables.

RESULTS

BNSL revealed two broad communities with markedly different topology between the populations of smokers, with and without periodontitis. Confidence of the edges in the resulting network also showed marked variations within and between the periodontitis and nonperiodontitis groups.

CONCLUSION

The results presented validated known associations and discovered new ones with minimal precedence that may warrant further investigation and novel hypothesis generation. Cross-talk between the clinical variables and antibody profiles of bacteria were especially pronounced in the case of periodontitis and were mediated by the antibody response profile to Porphyromonas gingivalis.

Immune system transcriptome in gingival tissues of young nonhuman primates

BACKGROUND AND OBJECTIVE

Young/adolescent humans harbor many microorganisms associated with periodontal disease in adults and show substantial gingival inflammatory responses. However, younger individuals do not demonstrate the soft- and hard-tissue destruction that hallmark periodontitis.

MATERIAL AND METHODS

This study evaluated responses to the oral microbial ecology in gingival tissues from clinically healthy young Macaca mulatta (< 3 years of age) compared with older animals (5-23 years of age). RNA was isolated from the tissues and analyzed for the transcriptome using the Rhesus Macaque GeneChip (Affymetrix).

RESULTS

Global transcriptional profiling of four age groups revealed a subset of 159 genes that were differentially expressed across at least one of the age comparisons. Correlation metrics generated a relevance network abstraction of these genes. Partitioning of the relevance network revealed seven distinct communities comprising functionally related genes associated with host inflammatory and immune responses. A group of genes was identified that were selectively increased/decreased or positively/negatively correlated with gingival profiles in the animals. A principal components analysis created metagenes of expression profiles for classifying the 23 animals.

CONCLUSION

The results provide novel system-level insights into gene-expression differences in gingival tissues from healthy young animals, weighted toward host responses associated with anti-inflammatory biomolecules or those linked with T-cell regulation of responses. The combination of the regulated microenvironment may help to explain the apparent 'resistance' of younger individuals to developing periodontal disease.