Personalized medicine: an update of salivary biomarkers for periodontal diseases

An experimental murine model to study periodontitis

Periodontal disease (PD) is a common dental disease associated with the interaction between dysbiotic oral microbiota and host immunity. It is a prevalent disease, resulting in loss of gingival tissue, periodontal ligament, cementum and alveolar bone. PD is a major form of tooth loss in the adult population. Experimental animal models have enabled the study of PD pathogenesis and are used to test new therapeutic approaches for treating the disease. The ligature-induced periodontitis model has several advantages as compared with other models, including rapid disease induction, predictable bone loss and the capacity to study periodontal tissue and alveolar bone regeneration because the model is established within the periodontal apparatus. Although mice are the most convenient and versatile animal models used in research, ligature-induced periodontitis has been more frequently used in large animals. This is mostly due to the technical challenges involved in consistently placing ligatures around murine teeth. To reduce the technical challenge associated with the traditional ligature model, we previously developed a simplified method to easily install a bacterially retentive ligature between two molars for inducing periodontitis. In this protocol, we provide detailed instructions for placement of the ligature and demonstrate how the model can be used to evaluate gingival tissue inflammation and alveolar bone loss over a period of 18 d after ligature placement. This model can also be used on germ-free mice to investigate the role of human oral bacteria in periodontitis in vivo. In conclusion, this protocol enables the mechanistic study of the pathogenesis of periodontitis in vivo.

Decreased salivary concentration of CD9 and CD81 exosome-related tetraspanins may be associated with the periodontal clinical status

AIM

This cross-sectional case-control study was designed to determine the association of the salivary concentration of CD9/CD81 exosome-related tetraspanins with the periodontal clinical status.

MATERIALS AND METHODS

Saliva samples from 104 periodontitis patients and 45 healthy controls were collected. Periodontal status was assessed based on full-mouth clinico-radiographical data, and salivary concentration of the analytes was calculated by ELISA. The association between the biomarkers with disease status was analysed using multivariate binary logistic regression models.

RESULTS

Significantly decreased salivary levels of CD9 and CD81 exosomes were detected in periodontitis patients in comparison with healthy controls. Also, negative significant correlations between salivary concentrations of CD9/CD81 exosomes regarding clinical measurements were observed. Likewise, a significant downward trend of the concentration of these two biomarkers concerning the stage and grade of disease could be identified. Logistic regression analyses revealed a strong/independent association for decreased salivary concentration of CD81 exosomes regarding disease status. Confounding and interaction effects between age and salivary concentration of CD9 exosomes were also noted.

CONCLUSION

Reduced salivary concentration of CD9/CD81 exosomes might be of significance in the context of periodontal disease pathogenesis.

A public health perspective on personalized periodontics

In this paper, we consider personalized periodontics from a public health perspective. Periodontitis is an under-acknowledged and important public health problem, and there has long been interest in identifying and treating those who are at high risk of developing this disease. Although susceptibility/risk-assessment tools in periodontology are currently in their early stages of development, personalized periodontics is increasingly becoming a realistic approach. At the population level, however, personalized periodontics is not an effective way of improving periodontal health because it would target only those who seek help or are able to access care. The occurrence of periodontitis in populations is socially patterned, with those of lower socio-economic position having poorer periodontal health and being far less likely to seek care. There is the potential for social inequalities actually to worsen as a result of personalized periodontics. In most health systems, personalized periodontics is likely to be accessible only to the social strata for whom it is affordable, and those with the greatest need for such an intervention will remain the least likely to be able to get it. Thus, personalized periodontics is likely to be a niche service for a small proportion of the adult population. This is at odds with the public health approach.

Lifestyle and periodontitis: The emergence of personalized periodontics

Personalized medicine is a medical model that involves the tailoring of healthcare - with medical decisions, practices, and/or products being customized to an individual patient. In this model, diagnostic testing is often employed for selecting appropriate and optimal therapies based on the context of a patient's genetic content or other epidemiologic, sociologic, molecular, physiologic, or cellular analyses. With the advent of major advances in periodontal medicine, including genomic discoveries and greater understanding of the multifactorial nature of periodontitis, it seems that the time is ripe to use personalized medicine as a model for personalized periodontics. This volume of Periodontology 2000 explores how new advances in our understanding of periodontitis within a medical model can evolve into new treatment strategies tailor-made for individual patients and not merely based on wholesale treatment paradigms.

Evaluation of Biochemical Parameters Present in the Saliva of Patients with Chronic Periodontitis: Results from a Meta-Analysis

AIMS

Periodontitis results from the presence of periodontopathogenic bacterial activity in the region of the gingival sulcus promoting tissue degradation and alveolar bone resorption. Biochemical analysis of the saliva can be used as a less invasive method for disease prognosis. This study aimed to evaluate the relationship between biochemical protein levels in the saliva sample of patients with chronic periodontitis and healthy patients.

MATERIALS AND METHODS

A literature review was performed using electronic databases (Cochrane Library, Google Scholar, MEDLINE, PubMed, and Web of Science) for studies published before July 2, 2016. The abstracts were evaluated, and the data extraction was performed by two calibrated examiners. The mean difference, and heterogeneity were calculated, and funnel plots were produced.

RESULTS

Twenty case-control studies were selected with 2436 patients with chronic periodontitis and 1787 controls. The meta-analysis showed that increased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and acid phosphatase (ACP) were all associated with periodontitis (p < 0.05), while blood urea nitrogen (BUN) and osteoprotegerin (OPG) levels did not show statistical differences between cases and controls (p > 0.05).

CONCLUSIONS

This meta-analysis evidenced that increased levels of AST, ALT, CK, gama glutamil transferase (GGT), LDH, ALP, and ACP are associated in patients with chronic periodontitis, while BUN and OPG level in saliva did not present differences between groups.

A New Approach for the Diagnosis of Systemic and Oral Diseases Based on Salivary Biomolecules

Early diagnosis represents the target of contemporary medicine and has an important role in the prognosis and further treatment. Saliva is a biofluid that generated a high interest among researchers due to its multiple advantages over other body fluids. The multitude of components that can act as biomarkers influenced the existing technologies to develop protocols that could allow saliva to become the new noninvasive diagnostic method. Saliva as a diagnostic tool can bring substantial addition to the diagnostic armamentarium, providing important information about oral and general health. The diagnostic applications of saliva extended and had a rapid evolution due to the advancement in salivaomics. The present review summarizes the latest researches in saliva-related studies and explores the information and correlations that saliva can offer regarding the systemic and oral diseases, highlighting its great potential of diagnosis. It is expected that in the future specific guidelines and results regarding the salivary diagnostics are to be available, together with high-sensitivity and specificity tests for multiple systemic and oral diseases.

Differential profiles of soluble and cellular toll like receptor (TLR)-2 and 4 in chronic periodontitis

Chronic periodontitis is a common inflammatory disease initiated by a complex microbial biofilm and mediated by the host response causing destruction of the supporting tissues of the teeth. Host recognition of pathogens is mediated by toll-like receptors (TLRs) that bind conserved molecular patterns shared by large groups of microorganisms. The oral epithelial cells respond to most periodontopathic bacteria via TLR-2 and TLR-4. In addition to the membrane-associated receptors, soluble forms of TLR-2 (sTLR-2) and TLR-4 (sTLR-4) have been identified and are thought to play a regulatory role by binding microbial ligands. sTLR-2 has been shown to arise from ectodomain shedding of the extracellular domain of the membrane receptor and sTLR-4 is thought to be an alternate spliced form. Many studies have previously reported the presence of elevated numbers of viable exfoliated epithelial cells in the saliva of patients with chronic periodontitis. The objective of this study was to investigate the potential value of salivary sTLR-2 and sTLR-4 together with the paired epithelial cell-associated TLR-2/4 mRNA as diagnostic markers for chronic periodontitis. Unstimulated whole saliva was collected after obtaining informed consent from 40 individuals with either periodontitis or gingivitis. The sTLR-2 and sTLR4 in saliva was measured by enzyme-linked immunosorbent assay. The TLR-2 and TLR-4 transcript in the epithelial cells in saliva was measured by real time polymerase chain reaction. While levels of sTLR-2 exhibited an inverse correlation, sTLR-4 positively correlated with clinical parameters in the gingivitis cohort. Interestingly, both correlations were lost in the periodontitis cohort indicating a dysregulated host response. On the other hand, while the sTLR-2 and the paired epithelial cell associated TLR-2 mRNA exhibited a direct correlation (r2 = 0.62), that of sTLR4 and TLR-4 mRNA exhibited an inverse correlation (r2 = 0.53) in the periodontitis cohort. Collectively, assessments of salivary sTLR2 and sTLR4 together with the respective transcripts in the epithelial cells could provide clinically relevant markers of disease progression from gingivitis to periodontitis.

Cytokine Thresholds in Gingival Crevicular Fluid with Potential Diagnosis of Chronic Periodontitis Differentiating by Smoking Status

The objective of the present study was to determine cytokine thresholds derived from predictive models for the diagnosis of chronic periodontitis, differentiating by smoking status. Seventy-five periodontally healthy controls and 75 subjects affected by chronic periodontitis were recruited. Sixteen mediators were measured in gingival crevicular fluid (GCF) using multiplexed bead immunoassays. The models were obtained using binary logistic regression, distinguishing between non-smokers and smokers. The area under the curve (AUC) and numerous classification measures were obtained. Model curves were constructed graphically and the cytokine thresholds calculated for the values of maximum accuracy (ACC). There were three cytokine-based models and three cytokine ratio-based models, which presented with a bias-corrected AUC > 0.91 and > 0.83, respectively. These models were (cytokine thresholds in pg/ml for the median ACC using bootstrapping for smokers and non-smokers): IL1alpha (46099 and 65644); IL1beta (4732 and 5827); IL17A (11.03 and 17.13); IL1alpha/IL2 (4210 and 7118); IL1beta/IL2 (260 and 628); and IL17A/IL2 (0.810 and 1.919). IL1alpha, IL1beta and IL17A, and their ratios with IL2, are excellent diagnostic biomarkers in GCF for distinguishing periodontitis patients from periodontally healthy individuals. Cytokine thresholds in GCF with diagnostic potential are defined, showing that smokers have lower threshold values than non-smokers.

Evaluation of chemokine CXCL10 in human gingival crevicular fluid, saliva, and serum as periodontitis biomarker

Purpose

The aim of this study was to evaluate CXCL10 as a biomarker for periodontitis by determining the CXCL10 levels in saliva, serum, and gingival crevicular fluid (GCF) samples from periodontally healthy control subjects and adult subjects with chronic periodontitis.

Patients and methods

Adult patients seeking dental treatment at Umm Al-Qura University dental clinic underwent a complete periodontal examination, and saliva, serum, and GCF samples were collected. Subjects were classified as chronic periodontitis patients (n=31) if they have a periodontal probing depth (PD) of ≥4 mm and/or clinical attachment level (CAL) of ≥3 mm in >30% of the teeth. The control group (n=25) had PD ≤3 mm and/or CAL ≤2 mm. ELISA was performed to determine the concentration of CXCL10 in saliva, serum, and GCF samples. Student’s t-test was carried out to evaluate the significant difference between different groups. Spearman’s correlation test was used to analyze the relationship between the levels of CXCL10 and the clinical periodontal parameters. P-value of ≤0.05 was considered significant.

Results

Significantly higher concentrations of CXCL10 were found in saliva and serum in chronic periodontitis patients as compared with the controls (272±60.4 pg/mL and 72±13.4 pg/mL vs 130±22.2 pg/mL and 44.08±4.5 pg/mL, P≤0.05). The CXCL10 levels in GCF were higher in the periodontitis group as compared with the control group (66.36±32.0 pg/mL and 44.56±17.5 pg/mL, respectively); the difference did not reach statistical significance (P≥0.05). Moreover, serum CXCL10 level was significantly higher in periodontitis patients with moderate to severe bone loss as compared with those with mild bone loss (71.05±4.7 pg/mL vs 54.8±7.7 pg/mL, P≤0.05). The serum CXCL10 levels were found to be related to CAL measurements (r=0.3, P=0.026), while the saliva CXCL10 levels were related to PD measurements (r=0.8, P=0.0007).

Conclusion

CXCL10 is significantly increased in periodontitis subjects as compared with controls and could be used as a marker for periodontal disease.

Salivary arginase activity after mechanical-chemical therapy

Abstract Introduction Salivary components can be used as biomarkers for diagnosing and monitoring oral diseases. There is evidence that one potential biomarker, arginase, is associated with the inflammatory processes of periodontal disease, and its enzymatic activity is reduced according to the improvement in the clinical parameters after treatment. Objective The present study aimed to evaluate the salivary arginase activity in gingivitis and periodontitis patients treated with full-mouth mechanical procedures combined with the adjunctive use of essential oils or chlorhexidine mouthwash, respectively. Material and method Twenty-six gingivitis and 16 periodontitis patients received complete periodontal examinations at the baseline and 3 months after therapy, in which the periodontal probing depth, clinical attachment loss, plaque index, and gingival index measurements were taken. At these same appointments, the salivary total protein level and salivary arginase activity were also established via spectrophotometry. Result There were improvements in all of the clinical parameters (p < 0.05) evaluated from the baseline to 3 months in both groups. In addition, the salivary arginase activity and total protein levels were reduced after the gingivitis treatment. Conclusion Similar to the clinical results, both therapeutic protocols positively affected the salivary arginase activity; however, further studies are necessary to clarify its potential as a salivary biomarker for periodontal monitoring.

Cumulative use of salivary markers with an adaptive design improves detection of periodontal disease over fixed biomarker thresholds

OBJECTIVE

Aim was to analyze the diagnostic ability of cumulative risk score (CRS), which uses salivary levels of Porphyromonas gingivalis, interleukin (IL)-1β, and matrix metalloproteinase (MMP)-8 in an adaptive design, compared to previously reported thresholds of each marker alone.

MATERIALS AND METHODS

Oral and general health information of 463 participants were included in the analysis. Having the percentage of bleeding on probing (BOP) > 25%, having at least two sites with probing pocket depth (PPD) of 4-5 mm or having at least one tooth with alveolar bone loss (ABL) of at least 1/3 of the root length were accepted as outcome variables. Being above the salivary threshold concentrations of P. gingivalis, IL-1β, and MMP-8 and CRS values were used as explanatory variables. Receiver operating characteristics (ROC) producing an area under the curve (AUC) and multinomial regression analysis were used in statistical analysis.

RESULTS

CRS provided AUCs larger than any other tested biomarker threshold. Sensitivity and specificity of CRS for detecting clinical markers of periodontitis were acceptable, and a strong association was observed between the highest CRS score and having at least two sites with PPD of 4-5 mm.

CONCLUSION

CRS brings additional power over fixed thresholds of single biomarkers in detecting periodontitis.

Diagnostic value of salivary CRP and IL-6 in patients undergoing anti-TNF-alpha therapy for rheumatic disease

Introduction

Saliva has been increasingly used as a diagnostic medium for disease detection and monitoring. The aim of this observational, prospective, pilot study was to investigate whether salivary concentrations of CRP and IL-6 correlate with those in serum and with the clinical course of a rheumatic disease.

Materials and methods

Nineteen patients with rheumatic disease newly scheduled for anti-TNFα therapy were included. Patients received anti-TNFα treatment (adalimumab, certolizumab, golimumab or infliximab) as per standard protocols. CRP and IL-6 were measured with high-sensitivity immunoassays before and after 12 weeks of therapy, according to standard regimens. The data were analyzed with nonparametric statistics.

Results

Concentrations of CRP in saliva correlated significantly with those in serum (R = 0.62; p < 0.0001) and decreased markedly after successful response to treatment. In patients with a limited response to treatment salivary CRP levels increased. In contrast to CRP, the salivary concentrations of IL-6 did not change significantly over the course of therapy and they did not correlate with serum IL-6 concentrations. Salivary levels of neither CRP nor IL-6 corresponded to parameters of oral health and hygiene.

Conclusions

Salivary CRP but not IL-6 could be of potential use for monitoring the rheumatic disease activity.

Periodontitis: facts, fallacies and the future

This volume of Periodontology 2000 represents the 25th anniversary of the Journal, and uses the occasion to assess important advancements in periodontology over the past quarter-century as well as the hurdles that remain. Periodontitis is defined by pathologic loss of the periodontal ligament and alveolar bone. The disease involves complex dynamic interactions among active herpesviruses, specific bacterial pathogens and destructive immune responses. Periodontal diagnostics is currently based on clinical rather than etiologic criteria, and provides limited therapeutic guidance. Periodontal causative treatment consists of scaling, antiseptic rinses and occasionally systemic antibiotics, and surgical intervention has been de-emphasized, except perhaps for the most advanced types of periodontitis. Plastic surgical therapy includes soft-tissue grafting to cover exposed root surfaces and bone grafting to provide support for implants. Dental implants are used to replace severely diseased or missing teeth, but implant overuse is of concern. The utility of laser treatment for periodontitis remains unresolved. Host modulation and risk-factor modification therapies may benefit select patient groups. Patient self-care is a critical part of periodontal health care, and twice-weekly oral rinsing with 0.10-0.25% sodium hypochlorite constitutes a valuable adjunct to conventional anti-plaque and anti-gingivitis treatments. A link between periodontal herpesviruses and systemic diseases is a strong biological plausibility. In summary, research during the past 25 years has significantly changed our concepts of periodontitis pathobiology and has produced more-effective and less-costly therapeutic options.

IL-6 and TNF-α salivary levels according to the periodontal status in Portuguese pregnant women

Background

Periodontitis is associated with increased concentration of inflammatory markers and saliva has been proposed as a non-invasive diagnostic fluid in oral and systemic diseases. The levels of salivary biomarkers, such as cytokines, could potentially be used to distinguish periodontal healthy individuals from subjects with periodontal disease. The purpose of this study was to characterize the salivary levels of two inflammatory biomarkers associated with periodontitis, interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), in order to assess whether these cytokines salivary levels could potentially be used to complement periodontitis pregnant women diagnose.

Methods

Forty-four pregnant women were distributed into three groups, according to their periodontal status: healthy, mild/moderate periodontitis and severe periodontitis. Unstimulated saliva was collected and analysis of TNF-α and IL-6 salivary levels were performed with Immulite^®.

Results

Women with periodontitis exhibited significantly higher levels (p = 0.001) of salivary IL-6 and TNF-α compared with the healthy group: 25.1 (±11.2) pg/mL vs. 16.3 (±5.0) pg/mL and 29.7 (±17.2) pg/mL vs. 16.2 (±7.6) pg/mL, approximately 1.5 and 1.8 times more, respectively. Additionally, cytokines were significantly increased (p < 0.05) in severe periodontitis compared to periodontal healthy pregnant women.

Conclusions

These results revealed that IL-6 and TNF-α salivary biomarkers provide high discriminatory capacity for distinguishing periodontal disease from periodontal health in pregnant women.

Relationship between Gingival Crevicular Fluid Microbiota and Cytokine Profile in Periodontal Host Homeostasis

As potential biomarkers in periodontitis, microbiome, and cytokines have recently been extensively investigated, but combined analyses of the variations between the microbial structure and cytokine composition are rare. The present study aimed to investigate whether there are differences in the combined profile of microbiome and cytokines in individuals with or without periodontitis. The microbiome and cytokine composition in gingival crevicular fluid (GCF) from 16 patients and 15 controls from Jishi Shan (Gansu, China) were analyzed using 454 pyrosequencing and RayBio Quantibody Arrays. The results showed that a higher co-occurrence of genera in periodontitis group compared with the healthy group, as evaluated by Schoener's abundance-based co-occurrence index. C-reactive protein (CRP) was significantly (P < 0.05) higher in the GCF of the periodontitis group while interleukin (IL)-8 was significantly (P < 0.01) higher in the GCF of the healthy group. The Mantel test revealed a significant concordance between cytokines and microbiota, in the healthy group (Mantel statistic r = 0.36, P ≤ 0.05) but not in the periodontitis group (Mantel statistic r = 0.013, P = 0.434). The results were further confirmed by the Procrustes test. Matrix metalloproteinase (MMP)-9, osteoactivin, IL-8, and macrophage inflammatory protein (MIP)-1a were significantly associated with bacterial composition at the phylum, class, order, family, and genus levels. CRP was also associated with bacterial composition at the species level. In conclusion, alterations in the polymicrobial community structure leads to disruption in the healthy correlation between cytokines and microbiomes. This dysbiosis between the microbiota and the immune response could be one of the major etiological mechanisms underlying periodontitis.

Cytokine-based Predictive Models to Estimate the Probability of Chronic Periodontitis: Development of Diagnostic Nomograms

Although a distinct cytokine profile has been described in the gingival crevicular fluid (GCF) of patients with chronic periodontitis, there is no evidence of GCF cytokine-based predictive models being used to diagnose the disease. Our objectives were: to obtain GCF cytokine-based predictive models; and develop nomograms derived from them. A sample of 150 participants was recruited: 75 periodontally healthy controls and 75 subjects affected by chronic periodontitis. Sixteen mediators were measured in GCF using the Luminex 100™ instrument: GMCSF, IFNgamma, IL1alpha, IL1beta, IL2, IL3, IL4, IL5, IL6, IL10, IL12p40, IL12p70, IL13, IL17A, IL17F and TNFalpha. Cytokine-based models were obtained using multivariate binary logistic regression. Models were selected for their ability to predict chronic periodontitis, considering the different role of the cytokines involved in the inflammatory process. The outstanding predictive accuracy of the resulting smoking-adjusted models showed that IL1alpha, IL1beta and IL17A in GCF are very good biomarkers for distinguishing patients with chronic periodontitis from periodontally healthy individuals. The predictive ability of these pro-inflammatory cytokines was increased by incorporating IFN gamma and IL10. The nomograms revealed the amount of periodontitis-associated imbalances between these cytokines with pro-inflammatory and anti-inflammatory effects in terms of a particular probability of having chronic periodontitis.

Quantification by qPCR of Pathobionts in Chronic Periodontitis: Development of Predictive Models of Disease Severity at Site-Specific Level

Currently, there is little evidence available on the development of predictive models for the diagnosis or prognosis of chronic periodontitis based on the qPCR quantification of subgingival pathobionts. Our objectives were to: (1) analyze and internally validate pathobiont-based models that could be used to distinguish different periodontal conditions at site-specific level within the same patient with chronic periodontitis; (2) develop nomograms derived from predictive models. Subgingival plaque samples were obtained from control and periodontal sites (probing pocket depth and clinical attachment loss <4 mm and >4 mm, respectively) from 40 patients with moderate-severe generalized chronic periodontitis. The samples were analyzed by qPCR using TaqMan probes and specific primers to determine the concentrations of Actinobacillus actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), Parvimonas micra (Pm), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythia (Tf), and Treponema denticola (Td). The pathobiont-based models were obtained using multivariate binary logistic regression. The best models were selected according to specified criteria. The discrimination was assessed using receiver operating characteristic curves and numerous classification measures were thus obtained. The nomograms were built based on the best predictive models. Eight bacterial cluster-based models showed an area under the curve (AUC) ≥0.760 and a sensitivity and specificity ≥75.0%. The PiTfFn cluster showed an AUC of 0.773 (sensitivity and specificity = 75.0%). When Pm and AaPm were incorporated in the TdPiTfFn cluster, we detected the two best predictive models with an AUC of 0.788 and 0.789, respectively (sensitivity and specificity = 77.5%). The TdPiTfAa cluster had an AUC of 0.785 (sensitivity and specificity = 75.0%). When Pm was incorporated in this cluster, a new predictive model appeared with better AUC and specificity values (0.787 and 80.0%, respectively). Distinct clusters formed by species with different etiopathogenic role (belonging to different Socransky’s complexes) had a good predictive accuracy for distinguishing a site with periodontal destruction in a periodontal patient. The predictive clusters with the lowest number of bacteria were PiTfFn and TdPiTfAa, while TdPiTfAaFnPm had the highest number. In all the developed nomograms, high concentrations of these clusters were associated with an increased probability of having a periodontal site in a patient with chronic periodontitis.

Salivary Levels of NLRP3 Inflammasome-Related Proteins as Potential Biomarkers of Periodontal Clinical Status

BACKGROUND

Emerging evidence suggests that activation of inflammasomes plays a central mechanism in pathogenesis of periodontitis. This study aims to compare salivary levels of nod-like receptor family pyrin domain containing protein (NLRP) 3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cysteine aspartase (caspase)-1, and interleukin (IL)-1β from individuals with aggressive (AgP) or chronic periodontitis (CP) and healthy controls (HC), as well as elucidate its association with periodontal clinical status.

METHODS

Saliva samples from individuals with CP (n = 75), AgP (n = 20), and HC (n = 69) were collected. Periodontal status was assessed by measurement of probing depth, clinical attachment level, and extent and severity of disease. Salivary levels of analytes were analyzed by enzyme-linked immunosorbent assay. Association between biomarkers with CP or AgP was analyzed using multivariate binary logistic regression models.

RESULTS

Significantly higher levels of NLRP3, ASC, and IL-1β were detected in periodontitis groups in comparison to the periodontally HC group. However, no significant differences were observed for caspase-1 levels between clinical groups, and only NLRP3 salivary concentration was significantly higher in AgP compared with CP patients. Also, positive significant correlations among NLRP3, ASC, and IL-1β salivary concentrations and clinical parameters were observed. Logistic regression analyses revealed a strong/independent association of NLRP3, ASC, and IL-1β salivary levels with CP and AgP.

CONCLUSION

Although the concentration of caspase-1 in saliva samples makes its determination useless for detection of periodontal disease and/or its severity, salivary levels of NLRP3, ASC, and IL-1β may act as strong/independent indicators of amount and extent of periodontal breakdown in both CP and AgP and could potentially be used for prevention and therapy of this group of diseases.

Investigation of a Novel Predictive Biomarker Profile for the Outcome of Periodontal Treatment

BACKGROUND

An ability to predict the response to conventional non-surgical treatment of a periodontal site would be advantageous. However, biomarkers or tests devised to achieve this have lacked sensitivity. The aim of this study is to assess the ability of a novel combination of biomarkers to predict treatment outcome of patients with chronic periodontitis.

METHODS

Gingival crevicular fluid (GCF) and subgingival plaque were collected from 77 patients at three representative sites, one healthy (probing depth [PD] ≤3 mm) and two diseased (PD ≥6 mm), at baseline and at 3 and 6 months after treatment. Patients received standard non-surgical periodontal treatment at each time point as appropriate. The outcome measure was improvement in probing depth of ≥2 mm. Concentrations of active enzymes (matrix metalloproteinase [MMP]-8, elastase, and sialidase) in GCF and subgingival plaque levels of Porphyromonas gingivalis, Tannerella forsythia, and Fusobacterium nucleatum were analyzed for prediction of the outcome measure.

RESULTS

Using threshold values of MMP-8 (94 ng/μL), elastase (33 ng/μL), sialidase (23 ng/μL), and levels of P. gingivalis (0.23%) and T. forsythia (0.35%), receiver operating characteristic curves analysis demonstrated that these biomarkers at baseline could differentiate healthy from diseased sites (sensitivity and specificity ≥77%). Furthermore, logistic regression showed that this combination of these biomarkers at baseline provided accurate predictions of treatment outcome (≥92%).

CONCLUSION

The "fingerprint" of GCF enzymes and bacteria described here offers a way to predict the outcome of non-surgical periodontal treatment on a site-specific basis.

Azithromycin as an adjunct to non-surgical periodontal therapy: a systematic review

The aim of this study was to investigate the current published work relating to the clinical benefits of the use of systemic azithromycin as an adjunct to non-surgical periodontal therapy. A published work search of PubMed, EMBASE and Cochrane Register of Controlled Trials up to 27 April 2016 was undertaken. The large degree of heterogeneity in the types of studies, treatment protocols, test subjects, sample size and exclusion criteria indicated that the use of narrative synthesis of all relevant studies was a valid method of review. Of the 194 eligible studies, 15 were found to be of relevance. The majority of studies demonstrated an additional clinical benefit when azithromycin is used as an adjunct to non-surgical periodontal therapy, particularly in deeper pockets (≥6 mm). In conclusion, the current body of research on the adjunctive use of systemic azithromycin in non-surgical periodontal therapy suggests there is a clinical benefit and that this benefit is greatest in deeper initial pockets (≥6 mm). The findings also suggest that future studies need to be more careful in subject selection to identify susceptible patients or at risk sites, both the immunoregulatory effects and antibiotic resistance of azithromycin needs to be reported, and that study populations need to be more homogeneous.

Essential and Toxic Metals in Oral Fluid-a Potential Role in the Diagnosis of Periodontal Diseases

Recently, many studies have investigated the relationship between the level of metals in the body and various diseases. The objective of this study was to examine any possible influence of periodontal disease upon the concentration of metals in oral fluid and blood and to explore the usability of applying cluster analysis coupled with the analysis of selected elements in oral fluid, calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), zinc (Zn), cadmium (Cd) and lead (Pb), for effectively distinguishing people affected by periodontitis from healthy individuals. The quantification of eight metals in oral fluid and blood samples was performed by two inductively coupled plasma techniques-inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Most of the examined elements were detected at elevated concentration in the oral fluid of periodontal patients. However, the differences were statistically significant in the case of three metals: Cu, Mg and Mn (p < 0.05). Approximately, fivefold increase in the concentration of Cu, threefold-elevated levels of Mn and a twofold increase in the concentration of Mg were found in the oral fluid of the periodontal patients compared to the controls. Cluster analysis confirmed the statistical significance of the differences in the level of metals in the oral fluid between the two groups in most cases, plus enabled the correct classification of the subjects into patients and controls. The relationship between concentrations of metals and periodontal disease may in the future serve to prevent the development of such disease.

Salivary Markers for Periodontal and General Diseases

The determination of biomarkers in saliva is becoming an important part of laboratory diagnostics and the prediction of not only periodontal, but also other tissue and organ diseases. Biomarkers in saliva (e.g., enzymes, protein markers, or oxidative stress markers) can be used for activity determination and for periodontal disease prognosis. Saliva also contains many markers which can predict the risk of certain diseases (e.g., diabetes mellitus, cardiovascular, oncology, endocrinology, and psychiatric diseases). The study of salivary components proteomics clearly shows the relationship of periodontal diseases and diseases of distant systems, organs, or tissues.