Host-derived salivary biomarkers in diagnosing periodontal disease: systematic review and meta-analysis

Realizing the clinical utility of saliva for monitoring oral diseases

In the era of personalized/precision health care, additional effort is being expended to understand the biology and molecular mechanisms of disease processes. How these mechanisms are affected by individual genetics, environmental exposures, and behavioral choices will encompass an expanding role in the future of optimally preventing and treating diseases. Considering saliva as an important biological fluid for analysis to inform oral disease detection/description continues to expand. This review provides an overview of saliva as a diagnostic fluid and the features of various biomarkers that have been reported. We emphasize the use of salivary biomarkers in periodontitis and transport the reader through extant literature, gaps in knowledge, and a structured approach toward validating and determine the utility of biomarkers in periodontitis. A summation of the findings support the likelihood that a panel of biomarkers including both host molecules and specific microorganisms will be required to most effectively identify risk for early transition to disease, ongoing disease activity, progression, and likelihood of response to standard periodontal therapy. The goals would be to develop predictive algorithms that serve as adjunctive diagnostic tools which provide the clinician and patient important information for making informed clinical decisions.

Periodontal disease and emerging point-of-care technologies for its diagnosis

Periodontal disease (PD), a chronic inflammatory disorder that damages the tooth and its supporting components, is a common global oral health problem. Understanding the intricacies of these disorders, from gingivitis to severe PD, is critical for efficient treatment, diagnosis, and prevention in dental care. Periodontal biosensors and biomarkers are critical in improving oral health diagnostic skills. Clinicians may accomplish early identification, tailored therapy, and efficient tracking of periodontal diseases by using these technologies, ushering in a new age of accurate oral healthcare. Traditional periodontitis diagnostic methods frequently rely on physical probing and visual examinations, necessitating the development of point-of-care (POC) devices. As periodontal disorders necessitate more precise and rapid diagnosis, incorporating novel innovations in biosensors and biomarkers becomes increasingly crucial. These innovations improve our capacity to diagnose, monitor, and adapt periodontal therapies, bringing in the next phase of customized and effective dental healthcare. The review discusses the characteristics and stages of PD, clinical treatment techniques, prominent biomarkers and infection-associated factors that may be employed to determine PD, biomedical sensing, and POC appliances that have been created so far to diagnose stages of PD and its progression profile, as well as predicting future developments in this field.

Salivary interleukin-17A and interleukin-18 levels in patients with celiac disease and periodontitis

Background

An increased level of interleukin-17A and interleukin-18 in the serum and intestinal mucosa of celiac disease patients reflecting the severity of villous atrophy and inflammation was documented. Thus, the objective of this study was to evaluate the concentrations of salivary-17A, interleukin-1 beta, and interleukin-18 in patients with celiac disease who are on a gluten-free diet, both with and without periodontitis, and to compare these levels with those in healthy individuals.

Methods

The study involved 23 participants with serologically confirmed celiac disease (CD) and 23 control subjects. The CD patients had been following a gluten-free diet (GFD) for a minimum of 1 year and had no other autoimmune disorders. The research involved collecting demographic data, conducting periodontal examinations, gathering unstimulated whole saliva, and performing enzyme-linked immunosorbent assays to measure salivary interleukin-17A, interleukin-1 beta, and interleukin-18 levels. Spearman's correlation analysis was utilized to explore the relationships between CD markers in patients on a GFD and their periodontal clinical findings.

Results

The periodontal findings indicated significantly lower values in celiac disease patients adhering to a gluten-free diet compared to control subjects (p = 0.001). No significant differences were found in salivary IL-17A, IL-18, and IL-1B levels between celiac disease patients and control subjects. Nevertheless, the levels of all interleukins were elevated in periodontitis patients in both the celiac and control groups. The IL-1 Beta level was significantly higher in periodontitis patients compared to non-periodontitis patients in the control group (p = 0.035). Significant negative correlations were observed between serum IgA levels and plaque index (r = -0.460, p = 0.010), as well as gingival index (r = -0.396, p = 0.030) in CD patients on a gluten-free diet.

Conclusion

Celiac disease patients on gluten-free diet exhibited better periodontal health compared to control subjects. However, increased levels of salivary IL-17A, IL-18 and IL-1B levels were associated with periodontitis. Additionally, serum IgA level was significantly inversely associated with periodontitis clinical manifestations and with salivary inflammatory mediators in CD patients on GFD.

Interleukin-38: A crucial player in periodontitis

BACKGROUND

The objective of this study was to compare the levels of gingival crevicular fluid (GCF), salivary, and serum matrix metalloproteinase-9, interleukin (IL)-17, IL-36γ, and IL-38 in individuals with healthy periodontium, gingivitis, and periodontitis and to evaluate their correlations with clinical periodontal parameters.

MATERIALS AND METHODS

Ninety systemically healthy and nonsmoking volunteers divided into a healthy (H) group (n = 30), a gingivitis (G) group (n = 30), and a periodontitis (P) group (n = 30) were included in this study. Clinical periodontal parameters of volunteers were recorded, and GCF, unstimulated saliva, and serum samples were collected. Data analysis was done with enzyme-linked immunosorbent assays. The Kruskal-Wallis test and Bonferroni correction were used for multiple comparisons and post hoc statistical analyses.

RESULTS

The group H had significantly lower clinical parameters than the group P (p < 0.001). GCF and salivary IL-36γ and IL-38 levels were significantly higher in the group P than in the H and G groups (p < 0.05). Positive correlations between biochemical findings and clinical periodontal parameters were observed.

CONCLUSIONS

IL-36γ and IL-38 levels in GCF, saliva, and serum correlate with clinical periodontal parameters and may play a role in determining the activity of periodontitis.

Advances in periodontal biomarkers

Due to technologic advancements, periodontology has witnessed a boost in biomarker research over the past three decades. Indeed, with the aid of omics, our understanding of the healthy periodontium, pathogenesis of periodontal diseases, and healing after periodontal treatment has improved significantly. Yet, the traditional methods, periodontal probing and radiographies, remain the most common methods to diagnose periodontal disease and monitor treatment. Although these approaches can produce reliable diagnostic outcomes, they generally detect disease only after significant tissue degradation thus making treatment outcome highly uncertain. Accordingly, laboratories worldwide have collaborated with clinicians to design accurate, rapid and cost-effective biomarkers for periodontal disease diagnosis. Despite these efforts, biomarkers that can be widely used in early disease diagnosis and for treatment outcome prediction are far from daily use. The aim of this chapter is to give a general overview on periodontal health and diseases, and review recent advancements in periodontal biomarker research. A second aim will discuss the strengths and limitations of translating periodontal biomarker research to clinical practice. Genetic biomarkers of periodontitis are not discussed as the available confirmatory data is scarce.

Host-microbiome associations in saliva predict COVID-19 severity

Established evidence indicates that oral microbiota plays a crucial role in modulating host immune responses to viral infection. Following severe acute respiratory syndrome coronavirus 2, there are coordinated microbiome and inflammatory responses within the mucosal and systemic compartments that are unknown. The specific roles the oral microbiota and inflammatory cytokines play in the pathogenesis of coronavirus disease 2019 (COVID-19) are yet to be explored. Here, we evaluated the relationships between the salivary microbiome and host parameters in different groups of COVID-19 severity based on their oxygen requirement. Saliva and blood samples (n = 80) were collected from COVID-19 and from noninfected individuals. We characterized the oral microbiomes using 16S ribosomal RNA gene sequencing and evaluated saliva and serum cytokines and chemokines using multiplex analysis. Alpha diversity of the salivary microbial community was negatively associated with COVID-19 severity, while diversity increased with health. Integrated cytokine evaluations of saliva and serum showed that the oral host response was distinct from the systemic response. The hierarchical classification of COVID-19 status and respiratory severity using multiple modalities separately (i.e. microbiome, salivary cytokines, and systemic cytokines) and simultaneously (i.e. multimodal perturbation analyses) revealed that the microbiome perturbation analysis was the most informative for predicting COVID-19 status and severity, followed by the multimodal. Our findings suggest that oral microbiome and salivary cytokines may be predictive of COVID-19 status and severity, whereas atypical local mucosal immune suppression and systemic hyperinflammation provide new cues to understand the pathogenesis in immunologically compromised populations.

Salivary levels of inflammatory and anti-inflammatory biomarkers in periodontitis patients with and without acute myocardial infarction: implications for cardiovascular risk assessment

Background

Periodontitis is initiated by a dysbiotic activity and furthermore leads to a chronic inflammatory response. The presence of pro-inflammatory markers plays an important role in the inflammatory load. Macrophage inflammatory protein-1 alpha (MIP-1α) and C-reactive protein (CRP) are pro- inflammatory biomarkers that quantify clinical and subclinical inflammation in cardiac ischemia in cardiac inflammation and disease. Adiponectin is an anti-inflammatory marker associated with good health. The susceptibility of periodontitis patients to cardiovascular events needs to be evaluated.

Objective

This study aims to assess the levels of biomarkers in periodontitis patients with and without acute myocardial infarction (AMI) compared to controls.

Material and methods

Pro-inflammatory and anti-inflammatory analytes were examined by collecting unstimulated saliva from three groups (n = 20/each): healthy individuals, individuals with stage III periodontitis, and post-myocardial infarction patients with stage III periodontitis. The samples were collected within 48 h of AMI.

Results

Adiponectin levels were significantly lower in patients with periodontitis with and without AMI compared to controls, while CRP and MIP-1α were significantly higher in patients with periodontitis with and without AMI compared to controls. The highest titers for MIP-1α and CRP were detected among patients with periodontitis with and AMI.

Conclusion

Our study provides possible evidence of the association between periodontitis and salivary analytes that occur in tandem with cardiovascular disease. The lower levels of Adiponectin and higher levels of CRP and MIP-1α in patients with periodontitis indicate that this condition is a potential risk factor for cardiovascular disease. The findings emphasize the importance of early detection and intervention for periodontitis patients to prevent cardiovascular events.

A novel plasmonic optical-fiber-based point-of-care test for periodontal MIP-1α detection

The analysis of salivary biomarkers as expression of periodontal health conditions has been proposed as a useful aid to conventional diagnostic approaches. In this study, we present a point-of-care test (POCT) exploiting a surface plasmon resonance (SPR)-based optical biosensor to detect salivary macrophage inflammatory protein (MIP)-1α, a promising marker of periodontitis. A plastic optical fiber (POF) was suitably modified and functionalized by an antibody self-assembled monolayer against MIP-1α for plasmonic detection. The proposed SPR-POF biosensor showed high selectivity and very low limit of detection for MIP-1α of 129 fM (1.0 pg/mL) in phosphate-buffered saline and 346 fM (2.7 pg/mL) in saliva. As a proof of concept, this POCT was also able to discriminate between a periodontitis patient and a healthy subject. The obtained results support the future application of this technology for an on-site detection and real-time monitoring of periodontal health conditions for diagnostic and therapeutic purposes.

Accuracy of periodontitis diagnosis obtained using multiple molecular biomarkers in oral fluids: A systematic review and meta-analysis

AIM

To determine the accuracy of biomarker combinations in gingival crevicular fluid (GCF) and saliva through meta-analysis to diagnose periodontitis in systemically healthy subjects.

METHODS

Studies on combining two or more biomarkers providing a binary classification table, sensitivity/specificity values or group sizes in subjects diagnosed with periodontitis were included. The search was performed in August 2022 through PUBMED, EMBASE, Cochrane, LILACS, SCOPUS and Web of Science. The methodological quality of the articles selected was evaluated using the QUADAS-2 checklist. Hierarchical summary receiver operating characteristic modelling was employed to perform the meta-analyses (CRD42020175021).

RESULTS

Twenty-one combinations in GCF and 47 in saliva were evaluated. Meta-analyses were possible for six salivary combinations (median sensitivity/specificity values): IL-6 with MMP-8 (86.2%/80.5%); IL-1β with IL-6 (83.0%/83.7%); IL-1β with MMP-8 (82.7%/80.8%); MIP-1α with MMP-8 (71.0%/75.6%); IL-1β, IL-6 and MMP-8 (81.8%/84.3%); and IL-1β, IL-6, MIP-1α and MMP-8 (76.6%/79.7%).

CONCLUSIONS

Two-biomarker combinations in oral fluids show high diagnostic accuracy for periodontitis, which is not substantially improved by incorporating more biomarkers. In saliva, the dual combinations of IL-1β, IL-6 and MMP-8 have an excellent ability to detect periodontitis and a good capacity to detect non-periodontitis. Because of the limited number of biomarker combinations evaluated, further research is required to corroborate these observations.

Biomarkers for diagnosis of stage III, grade C with molar incisor pattern periodontitis in children and young adults: a systematic review and meta-analysis

AIM

To explore the existing salivary, gingival crevicular fluid (GCF), blood, and serum biomarkers associated with grade C molar-incisor pattern (C/MIP) periodontitis in systemically healthy children and young adults.

MATERIALS AND METHODS

Cross-sectional, case-control, and cohort studies on stage III grade C periodontitis or former equivalent diagnosis with analysis of molecular biomarkers in saliva, GCF, blood, or serum were retrieved from six databases and screened based on the eligibility criteria. The risk of bias in included studies was evaluated. Meta-analysis was planned for biomarkers assessed using the same detection methods and sample type in at least two papers.

RESULTS

Out of 5621 studies identified at initial screening, 28 papers were included in the qualitative analysis of which 2 were eligible for meta-analysis for IgG in serum samples. Eighty-seven biomarkers were assessed with the majority being higher in cases than in controls. Only the meta-analysis of total serum IgG with low heterogeneity value revealed a significant increase in its levels in C/MIPs compared to controls (standardised mean difference: 1.08; 95% CI: 0.76, 1.40).

CONCLUSION

There is a paucity of data on biomarkers associated with molar-incisor pattern periodontitis. Although serum IgG levels are raised, other more specific biomarkers in saliva, GCF, and blood/serum may be promising but require further investigation.

Integrated dual-channel electrochemical immunosensor for early diagnosis and monitoring of periodontitis by detecting multiple biomarkers in saliva

Periodontitis, as the sixth prevalence chronic inflammation worldwide, has inconspicuous and often-overlooked symptoms at early stage, eventually leading to permanent damage to the teeth and supporting tissues. The timely and accurate diagnosis of periodontitis and monitoring its progress appear to be particularly important for clinical treatment. Herein, a dual-channel electrochemical immunosensor was developed for the synchronized detection of two periodontitis-related biomarkers in saliva: interleukin-1β (IL-1β) and matrix metalloproteinase-8 (MMP-8). Owing to its miniaturization, detachability, and portability, this sensor has the potential to detect multiple biomarkers in a point-of-care manner for the early diagnosis and monitoring of periodontitis. The nanocomposites consisted of iridium oxide nanotubes and two-dimensional MXene nanosheets enhance the electrochemical performance of the sensor, achieving excellent sensitivity with wide detection ranges of 0.1-100 and 1-200 ng mL^-1, low limits of detection of 0.014 and 0.13 ng mL^-1, and relatively high correlation coefficients of 0.9911 and 0.9990 for IL-1β and MMP-8, respectively. Furthermore, this device possesses excellent selectivity in complex samples without cross-talk, as well as high recovery and accuracy in spiked artificial saliva. Importantly, the dual-channel device achieves higher diagnostic accuracy for different stages of periodontitis when MMP-8 and IL-1β were simultaneously monitored within clinicopathological saliva. This work proposes a considerable potential for early diagnosis and severity distinguishment of periodontitis in a point-of-care manner, which would be beneficial for progression prediction, treatment guidance, and prognosis assessment of periodontitis.

Associations between saliva and plasma cytokines in cognitively normal, older adults

BACKGROUND

Inflammatory responses play key roles in the development and progression of many pathological conditions, including neurodegenerative diseases. Accurate quantification of inflammatory factors in saliva would be highly advantageous, given its convenience and non-invasive nature, especially in elderly populations.

METHODS

In this study, we measured levels of 10 cytokines, and the pro-inflammatory factor, YKL-40, in plasma and saliva samples from a cohort of nondemented older adults (n = 71; 62% female; 70.3 ± 6.4 years) using sensitive electrochemiluminescence-based immunoassays.

RESULTS

We found that the mean levels of all cytokines were higher in saliva compared to plasma and that strong sex differences were observed for both saliva and plasma cytokines in this population. Comparing each cytokine between the two biofluids, we found that levels of interferon-gamma (IFNγ), interleukin (IL)-6 and tumor necrosis factor-alpha (TNFα) in blood were significantly correlated with their respective levels in saliva. We further observed that levels of these cytokines in blood were significantly correlated with additional cytokines in saliva, including IL-1β, IL-10, IL-8, IL12p70 and IL-13.

CONCLUSIONS

These findings show that inflammatory markers in saliva are associated with those found in circulation, suggesting shared inflammatory mechanisms between these two fluids. The higher levels of cytokines measured in saliva suggest that it might represent a better peripheral fluid to gauge inflammatory processes. Finally, our findings of robust sex differences in several salivary cytokines could have important implications for their potential use as disease biomarkers in the elderly and might be related to sex differences in the prevalence of age-related conditions.

Evaluation of Salivary Biomarkers of Periodontal Disease Based on Smoking Status: A Systematic Review

Saliva is a useful biomarker for diagnosing oral health conditions, including periodontal disease (PD). Smoking is a risk factor for PD. The aim of this systematic review was to summarize the salivary biomarkers associated with PD based on smoking status. A comprehensive search of the MEDLINE (via PubMed), EMBASE, Cochrane, SCOPUS, and Web of Sciences databases was conducted up to 1 January 2021 using key terms relevant to the topic of our research and Cochrane methodology and improved with searching a gray literature resource. The methodological quality of all included studies was assessed with the revised Quality Assessment of Diagnostic Accuracy Studies-2. Seven studies were included. Smokers had increased levels of malondialdehyde, sialic acid, salivary cortisol, salivary interleukin 1β, albumin, tissue inhibitor of matrix metalloproteinase (TIMP), and the pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), as well as decreased levels of superoxide dismutase, activity of lactate dehydrogenase, activity of enzyme activity of β-glucuronidase, uric acid, matrix metalloproteinase-8 (MMP-8)/TIMP-1 ratio, and combinations of MMP-8 and ICTP. However, mixed results were observed some studies in detecting glutathione peroxidase, MMP-8, and MMP-14. The results were interpreted with caution because of limitations in the number of included studies and the study design. Some salivary biomarkers are potentially useful in combination or alone for diagnosing PD. Methodological and systematic studies are needed to develop more effective biomarkers.

The effectiveness of the use of polypeptide drugs and their effect on the metabolic parameters of oral fluid in patients with generalized periodontitis in depending on blood type

The article presents the results of treatment of 157 patients with generalized periodontitis depending on blood type using polypeptide drugs. The concentration of total protein, C – reactive protein, IgG, TRACP, BSALP, albumin, amylase, lipase, Ca, Fe was determined in the oral fluid. The treatment allowed to reduce the content of total protein, C – reactive protein, TRACP in the oral fluid with increasing levels of calcium, Fe, BSALP, in relation to the relevant data before treatment. And also, polypeptide drugs helped to increase the level of albumin in representatives of 0 (I) and A (II) blood type in the oral fluid; contributed to a decrease: glucose, IgG with increasing activity, amylase and lipase in carriers of B (III) and AB (IV) blood type in the oral fluid, in relation to the values before treatment. The dynamics of indicators of oral fluid metabolism with the help of polypeptide drugs, convincingly proves the effectiveness of their use in the treatment of generalized periodontitis in patients with different blood type.

Changes in salivary matrix metalloproteinase-3, -8, and -9 concentrations after 6 weeks of non-surgical periodontal therapy

Background

Studies using salivary inflammatory biomarkers for diagnosing and monitoring the progression of periodontal disease have garnered increased attention in recent years. The present study aimed to identify changes in clinical parameters and concentrations of salivary matrix metalloproteinases (MMPs) following 6 weeks of non-surgical periodontal therapy (NSPT).

Methods

A 6-week NSPT program was applied to 51 adults aged ≥ 20 years. The program involved scaling, root planing, and professional toothbrushing for healthy participants and those with periodontal disease. Patients with periodontal disease underwent professional toothbrushing during all three visits. Periodontal pocket depth (PD) and gingival bleeding were assessed at week 0, week 3, and week 6, and saliva samples were collected to measure the concentrations of MMP-3, -8, and -9.

Results

All clinical parameters were improved in the periodontal disease groups following the NSPT course. Compared with healthy participants, the patients with periodontal disease showed increased concentrations of salivary MMP-3, -8, and -9. During the 6-week program, patients with periodontal disease also showed significant reductions in PD and gingival bleeding during the third week; no significant reduction was found during the sixth week. Significant reductions in the concentrations of salivary MMP-3, -8, and -9 were also noted in the periodontal disease group at week 3. The sensitivity and specificity of MMP-3 for predicting periodontitis were 81.8% and 55.5%, respectively.

Conclusion

The present study found that NSPT resulted in reductions of salivary MMP-3, -8, and -9, and identified the potential of MMP-3 as a biomarker in the diagnosis of periodontal disease. These findings may serve as foundational data for future studies into the development of diagnostic kits for periodontal disease.

Salivary Biomarkers in Periodontitis Patients: A Pilot Study

Background and Objective. Periodontal disease is a chronic inflammatory condition, involving the destruction of both soft and hard tissues in the periodontal region. Advances in diagnostic research are moving toward methods whereby the periodontal risk can be identified and quantified by objective measures using specific inflammatory markers that can be correlated to the severity of the disease. The purpose of this study was to evaluate salivary concentrations of IL-1β, IL-6, MMP-8, and IL-10 in healthy and periodontitis patients and to assess the association between these biomarkers levels and clinical parameters in a Moroccan population. Materials and Methods. Forty subjects were included: 10 periodontally healthy subjects and 30 periodontitis patients. Periodontal examination and saliva sampling were performed in all patients. Levels of salivary cytokines including IL-1β, IL-6, MMP-8, and IL-10 were evaluated by a sandwich ELISA test kit. Data were analyzed by SPSS for Windows. Results. Regarding individual biomarkers, IL-1β, IL-6, and MMP-8 levels were significantly higher in periodontitis patients ( $p\le 0.001$ , $p<\text{0.}05$ , respectively). The concentration of these proteins in saliva showed a significant association with gingival index and pocket depth measurements and may reflect the clinical status of healthy and diseased periodontium. However, no significant differences were observed for the IL-10 component. Conclusion. IL-1β and IL-6 concentrations were statistically higher in periodontitis patients and may be used as potential tools in periodontitis diagnosis.

Salivary Pro-Inflammatory Markers and Smoking Status Influences the Treatment Effectiveness of Periodontal Disease Patients with Hypertension

BACKGROUND

Hypertension and periodontal diseases share several risk factors. Inflammation biomarkers in saliva are related to hypertension and periodontal disease. The aim of this study was to explore the role of the salivary inflammatory biomarkers in the treatment effectiveness of patients with hypertension and periodontal disease.

METHODS

This observational study enrolled 160 subjects diagnosed with periodontitis, 40 of which had a history of hypertension. All subjects had completed scaling and root planning therapeutic procedures within four weeks. The clinical periodontal parameters (i.e., bleeding on probing, plaque control record (PCR), and probing depth (PD)) were evaluated before and after the treatment. Pro-inflammatory markers were determined using a commercial kit.

RESULTS

The recovery rate (PD 4-9 mm) in non-hypertensive subjects was significantly higher than in hypertensive subjects (60.47% vs. 52.60%, respectively; p = 0.04). All clinical parameters, excluding PCR, positively correlated with salivary IL-1β at baseline and after completing treatment. Our results showed that increased salivary IL-1β levels were positively associated with decreased PCR (β = -27.65 and p = 0.05) and PD recovery rate (β = -17.05 and p = 0.02) in hypertensive subjects.

CONCLUSIONS

The present study sheds important light on the clinical use of salivary pro-inflammatory cytokines as valuable biomarkers for predicting the treatment effectiveness of patients suffering from hypertension and periodontitis.

Saliva as a Source of Biomarkers for Periodontitis and Periimplantitis

Saliva has the potential to be used as a diagnostic and monitoring tool for various diseases if biomarkers of an adequate sensitivity and specificity could be identified. Several reviews and even meta-analyses have been performed in recent years, which have found some candidate biomarkers for periodontitis, like macrophage inflammatory protein-1 alpha, interleukin-1ß, interleukin-6, matrix metalloproteinase-8, or hemoglobin. However, none of those are currently in use to replace conventional periodontal diagnostics with a periodontal probe. For periimplantitis, to date, heterogeneity of different study protocols and implant types did not permit to discover clear biomarkers, which were able to distinguish between healthy and diseased implants. Few proinflammatory cytokines, similar to periodontitis, have been characterized as adjunct tools to clinical diagnosis. The additional determination of antimicrobial peptides, bone turnover markers, and bacteria could help to enhance sensitivity and specificity in a combined model for periodontitis and periimplantitis. Furthermore, proteomic approaches might be preferred over single biomarker determinations. A global consensus is also needed to harmonize salivary sampling methods as well as procedures of biomarker analysis to ensure future comparability.

Predictive Periodontitis: The Most Promising Salivary Biomarkers for Early Diagnosis of Periodontitis

The primary cause of tooth loss in the industrialized world is periodontitis, a bacterial anaerobic infection whose pathogenesis is characterized by composite immune response. At present, the diagnose of periodontitis is made by a complete status check of the patient’s periodontal health; full-mouth plaque score, full-mouth bleeding score, probing depth, clinical attachment level, bleeding on probing, recessions, mobility, and migration are evaluated in order to provides a clear picture of the periodontal conditions of a single patient. Chair-side diagnostic tests based on whole saliva could be routinely used by periodontists for a very early diagnosis of periodontitis, monitoring, prognosis, and management of periodontal patients by biomarker detection, whose diagnostic validity is related to sensitivity and specificity. Recent paper reviews and meta-analyses have focused on five promising host derived biomarkers as candidate for early diagnosis of periodontitis: MMP-8 (Metalloproteinase-8), MIP-1α (Macrophage inflammatory protein-1 alpha), IL-1 β (Interleukin-1 beta), IL-6 (Interleukin-6), and HB (Hemoglobin), and their combinations. Chair-side Lab-on-a-chip (LOC) technology may soon become an important part of efforts to detect such biomarkers in saliva medium to improve worldwide periodontal health in developed nations as well as in underserved communities and poor countries. Their applications in preventive and predictive medicine is now fundamental, and is aimed at the early detection of risk factors or the presence or evolution of the disease, and in personalized medicine, which aims to identify tailor-made treatments for individual patients. The aim of the present paper is to be informative about host derived periodontal biomarkers and, in particular, we intend to report information about the most important immune response derived biomarkers and Hemoglobin as candidates to be routinely utilized in order to obtain a chair-side early diagnosis of periodontal disease.

Salivary metabolomics for the diagnosis of periodontal diseases: a systematic review with methodological quality assessment

INTRODUCTION

Early diagnosis of periodontitis by means of a rapid, accurate and non-invasive method is highly desirable to reduce the individual and epidemiological burden of this largely prevalent disease.

OBJECTIVES

The aims of the present systematic review were to examine potential salivary metabolic biomarkers and pathways associated to periodontitis, and to assess the accuracy of salivary untargeted metabolomics for the diagnosis of periodontal diseases.

METHODS

Relevant studies identified from MEDLINE (PubMed), Embase and Scopus databases were systematically examined for analytical protocols, metabolic biomarkers and results from the multivariate analysis (MVA). Pathway analysis was performed using the MetaboAnalyst online software and quality assessment by means of a modified version of the QUADOMICS tool.

RESULTS

Twelve studies met the inclusion criteria, with sample sizes ranging from 19 to 130 subjects. Compared to periodontally healthy individuals, valine, phenylalanine, isoleucine, tyrosine and butyrate were found upregulated in periodontitis patients in most studies; while lactate, pyruvate and N-acetyl groups were the most significantly expressed in healthy individuals. Metabolic pathways that resulted dysregulated are mainly implicated in inflammation, oxidative stress, immune activation and bacterial energetic metabolism. The findings from MVA revealed that periodontitis is characterized by a specific metabolic signature in saliva, with coefficients of determination ranging from 0.52 to 0.99.

CONCLUSIONS

This systematic review summarizes candidate metabolic biomarkers and pathways related to periodontitis, which may provide opportunities for the validation of diagnostic or predictive models and the discovery of novel targets for monitoring and treating such a disease (PROSPERO CRD42020188482).

Changes in Inflammatory Cytokines in Saliva after Non-Surgical Periodontal Therapy: A Systematic Review and Meta-Analysis

To determine the diagnostic value of inflammatory cytokines in periodontal disease, we performed a systematic review of the changes in inflammatory cytokines after non-surgical periodontal therapy and a meta-analysis of the utility of interleukin (IL)-1β and matrix metalloproteinase (MMP)-8 as salivary biomarkers. All available papers published in English until 20 August 2020, were searched in the MEDLINE and EMBASE databases. Population, intervention, comparison, and outcome data were extracted from the selected studies, and the roles of IL-1β and MMP-8 were assessed in a meta-analysis. Eleven studies, including two meta-analyses, were assessed in the systematic review. Biomarkers showing high levels in periodontal disease were salivary IL-1β, IL-4, IL-6, MMP-8, and tissue inhibitor of matrix metalloproteinases (TIMP)-2, and those in the controls were tumor necrosis factor (TNF)-α, IL-10, IL-17, and IL-32. Biomarkers that decreased after scaling and root planning (SRP) and oral hygiene instruction (OHI) in periodontitis patients were IL-1β, MMP-8, MMP-9, prostaglandin E2 (PGE₂), and TIMP-2. The pooled standardized mean difference of IL-1β and MMP-8 was −1.04 and 35.90, respectively, but the differences between periodontitis patients and healthy controls were not significant. Although the changes in salivary IL-1β and MMP-8 levels after non-surgical periodontal therapy were not significant, salivary cytokines could be used to confirm the effect of periodontal therapy or diagnose periodontal disease.

Salivary biomarkers for discriminating periodontitis in the presence of diabetes

AIM

Salivary biomarkers can help in assessment of periodontitis; however, concentrations may be altered in the presence of diabetes. Hence, the ability of salivary biomarkers to discriminate periodontally healthy type II diabetics (T2DM) from T2DM who have periodontitis was examined.

METHODS

Ninety-two participants (29 with T2DM with chronic periodontitis, DWP; 32 T2DM without chronic periodontitis, DWoP; and 31 Not Periodontitis, NP) provided saliva and clinical parameters of periodontal health were recorded. Salivary concentrations of interleukin (IL)-1β, IL-6, matrix metalloproteinase-8 (MMP-8), macrophage inflammatory protein-1α (MIP-1α), adiponectin and resistin were measured by immunoassay.

RESULTS

Salivary analyte concentrations for IL-1β, MMP-8 and resistin correlated with clinical parameters of periodontitis, with MMP-8 demonstrating the strongest positive correlation with PD ≥5 mm (p < 0.0001). Periodontal health was reflected in salivary analyte concentrations by group, with concentrations of IL-1β and MMP-8 showing significant associations with periodontitis (p ≤ 0.04) that increased in concentration from health to DWoP to DWP. Odds ratio (OR) analyses showed that MMP-8 discriminated periodontitis from NP (OR of 8.12; 95% CI: 1.01-65.33; p = 0.03) and in the presence of T2DM (DWP vs DWoP, OR = 5.09; 95% CI: 1.24-20.92; p = 0.03).

CONCLUSION

Salivary MMP-8 and IL-1β discriminate periodontitis in T2DM.

A review of T helper 17 cell-related cytokines in serum and saliva in periodontitis

Periodontitis is a chronic inflammatory disease with a complex underlying immunopathology. Cytokines, as molecular mediators of inflammation, play a role in all stages of disease progression. T helper 17 (Th17) cells are thought to play a role in periodontitis. Th17 cell development and maintenance requires a pro-inflammatory cytokine milieu, with many of the cytokines implicated in the pathogenesis of periodontitis. Serum and saliva are easily accessible biofluids which can represent the systemic and local environment to promote the development of Th17 cells. Here we review human clinical studies that investigate IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α in serum and saliva in periodontitis. We highlight their putative role in the pathogenesis of periodontitis and place them within a wider context of animal and other clinical studies.

T helper 17 cell-related cytokines in serum and saliva during management of periodontitis

AIM

T helper (Th)17 cells are implicated in the pathogenesis of periodontitis. This study investigated the effect of periodontal management on fifteen Th17-related cytokines in serum and saliva in periodontitis patients.

MATERIALS AND METHODS

Periodontal parameters, serum and saliva were collected from 40 healthy controls and 54 periodontitis subjects before treatment, and 3-, 6- and 12-months post-treatment. Cytokine concentrations of IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α were determined by Luminex assay.

RESULTS

IL-1β, IL-6, sCD40L and TNF-α in serum, and IL-1β, IL-6, IL-25 and IL-31 in saliva were significantly higher at baseline compared to health and decreased with treatment. In contrast, serum IL-31 was significantly lower at baseline compared to health and increased with treatment. In addition, salivary IL-10, IL-17A, IL-17F, IL-23, IL-33, IFN-γ and TNF-α also displayed treatment-related reduction. Correlation networks showed that cytokines in saliva displayed a higher number of correlations compared to serum in periodontitis.

CONCLUSION

Treatment generally decreased cytokine concentrations except for serum IL-31 which showed a treatment-related increase. Serum cytokine concentrations may not be reflective of salivary cytokines. Saliva may be a better medium for cytokine detection compared to serum. Serum IL-31 and salivary IL-1β, IL-6, IL-10 and TNF-α were significant predictors for mean probing depth and may be potential biomarkers of interest in the pathogenesis of periodontitis.

Diagnostic sensitivity and specificity of host-derived salivary biomarkers in periodontal disease amongst adults: Systematic review

OBJECTIVE

To systematically assess the diagnostic value of host-derived salivary biomarkers based on their reported sensitivity and specificity in relation to clinical parameters of periodontal disease diagnosis in adults.

MATERIALS AND METHODS

Comprehensive search of PubMed, Nature, Cochrane and OVID (Embase, MEDLINE [R] and PsycINFO) was conducted up to 1 August 2018, using key terms relevant to the research questions and Cochrane methodology, supplemented by a grey literature search. The revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS- 2) tool was used to assess the methodological quality of all included studies.

RESULTS

Seven studies were included in the review. Macrophage inflammatory protein-1αlpha (MIP-1α), interleukin-1beta (IL-1β), interleukin-6 (IL-6) and matrix metalloproteinase-8 (MMP-8) were identified as diagnostically acceptable biomarkers for periodontal disease. Overall, the combination of IL-6 and MMP-8 showed best diagnostic performance. Also, a combination of the four key biomarkers (IL-1β, IL-6, MMP-8 and MIP-1α) showed promising results for distinction between gingivitis and periodontitis, as well as for periodontitis compared with gingival health. Results are interpreted with caution due to limitations in the number of studies included and their quality.

CONCLUSION

Certain salivary biomarkers can potentially be useful in combination and singularly for the diagnosis of periodontal disease. However, further methodically robust research is required to validate these biomarkers.

Salivary neuropeptides, stress, and periodontitis

BACKGROUND

Scientific evidence for psychologic stress as a risk factor for periodontitis is fragmentary and relies mostly on either questionnaire-based or biomarker studies. The aim of this study is to investigate brain-derived neurotrophic factor, substance P, vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), calcitonin gene-related peptide, and adrenomedullin as well as cortisol in saliva and serum in periodontal health and disease combined with different aspects of stress and possible associations with clinical parameters.

METHODS

In total, 56 patients with aggressive and chronic periodontitis and 44 healthy controls were screened by enzyme-linked immunosorbent assay and mass spectrometry for presence of neuropeptides and cortisol in saliva and serum. Psychologic stress was evaluated by validated questionnaires. All substances were explored for a possible relationship to periodontitis, clinical parameters, and stress.

RESULTS

VIP and NPY showed significantly higher levels in saliva but not in serum of patients with periodontitis. These neuropeptides correlated with the extent, severity, and bleeding on probing scores in patients with periodontitis. Females had significantly lower salivary VIP levels. There were no differences among participants regarding psychologic stress.

CONCLUSION

VIP and NPY in saliva could be potential sex-specific salivary biomarkers for periodontitis regardless of psychologic stress.

Accuracy of single molecular biomarkers in saliva for the diagnosis of periodontitis: A systematic review and meta-analysis

AIM

To analyse, using a meta-analytical approach, the diagnostic accuracy of single molecular biomarkers in saliva for the detection of periodontitis in systemically healthy subjects.

MATERIALS AND METHODS

Articles on molecular biomarkers in saliva providing a binary contingency table (or sensitivity and specificity values and group sample sizes) in individuals with clinically diagnosed periodontitis were considered eligible. Searches for candidate articles were conducted in six electronic databases. The methodological quality was assessed through the tool Quality Assessment of Diagnostic Studies. Meta-analyses were performed using the Hierarchical Summary Receiver Operating Characteristic model.

RESULTS

Meta-analysis was possible for 5 of the 32 biomarkers studied. The highest values of sensitivity for the diagnosis of periodontitis were obtained for IL1beta (78.7%), followed by MMP8 (72.5%), IL6 and haemoglobin (72.0% for both molecules); the lowest sensitivity value was for MMP9 (70.3%). In terms of specificity estimates, MMP9 had the best result (81.5%), followed by IL1beta (78.0%) and haemoglobin (75.2%); MMP8 had the lowest specificity (70.5%).

CONCLUSIONS

MMP8, MMP9, IL1beta, IL6 and Hb were salivary biomarkers with good capability to detect periodontitis in systemically healthy subjects. MMP8 and IL1beta are the most researched biomarkers in the field, both showing clinically fair effectiveness for the diagnosis of periodontitis.

Identification of Salivary Microbiota and Its Association With Host Inflammatory Mediators in Periodontitis

Periodontitis is a microbial-induced chronic inflammatory disease, which may not only result in tooth loss, but can also contribute to the development of various systemic diseases. The transition from healthy to diseased periodontium depends on microbial dysbiosis and impaired host immune response. Although periodontitis is a common disease as well as associated with various systemic inflammatory conditions, the taxonomic profiling of the salivary microbiota in periodontitis and its association with host immune and inflammatory mediators has not been reported. Therefore, the aim of this study was to identify key pathogens and their potential interaction with the host's inflammatory mediators in saliva samples for periodontitis risk assessment. The microbial 16S rRNA gene sequencing and the levels of inflammatory mediators were performed in saliva samples from patients with chronic periodontitis and periodontally healthy control subjects. The salivary microbial community composition differed significantly between patients with chronic periodontitis and healthy controls. Our analyses identified a number of microbes, including bacteria assigned to Eubacterium saphenum, Tannerella forsythia, Filifactor alocis, Streptococcus mitis/parasanguinis, Parvimonas micra, Prevotella sp., Phocaeicola sp., and Fretibacterium sp. as more abundant in periodontitis, compared to healthy controls. In samples from healthy individuals, we identified Campylobacter concisus, and Veillonella sp. as more abundant. Integrative analysis of the microbiota and inflammatory mediators/cytokines revealed associations that included positive correlations between the pathogens Treponema sp. and Selenomas sp. and the cytokines chitinase 3-like 1, sIL-6Rα, sTNF-R1, and gp130/sIL-6Rβ. In addition, a negative correlation was identified between IL-10 and Filifactor alocis. Our results reveal distinct and disease-specific patterns of salivary microbial composition between patients with periodontitis and healthy controls, as well as significant correlations between microbiota and host-mediated inflammatory cytokines. The positive correlations between the pathogens Treponema sp. and Selenomas sp. and the cytokines chitinase 3-like 1, sIL-6Rα, sTNF-R1, and gp130/sIL-6Rβ might have the future potential to serve as a combined bacteria-host salivary biomarker panel for diagnosis of the chronic infectious disease periodontitis. However, further studies are required to determine the capacity of these microbes and inflammatory mediators as a salivary biomarker panel for periodontitis.

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.

Evaluation of milk fat globule-epidermal growth factor-factor VIII and IL-1β levels in gingival crevicular fluid and saliva in periodontal disease and health

The aim of this study is to determine the levels of MFG-E8 and interleukin (IL)-1β in saliva and gingival crevicular fluid (GCF) associated with periodontal health and disease. Whole saliva and GCF samples were obtained from systemically healthy participants who were either periodontally healthy (n = 24) or suffered from gingivitis (n = 25) or chronic periodontitis (n = 25). Full-mouth clinical periodontal measurements, including bleeding on probing, probing depth, gingival index, plaque index, and clinical attachment level were also recorded. Enzyme-linked immunosorbent assay was used to estimate MFG-E8 and IL-1β levels in the samples. Analysis of variance, Kruskal-Wallis tests, and Pearson correlation tests were used to analyse the data statistically. The total level of MFG-E8 in GCF was significantly higher in the healthy group than in the other two groups (P = 0.01). Salivary MFG-E8 levels did not differ significantly among the groups. There were negative correlations between the level of MFG-E8 in GCF and probing depth (P = 0.03), bleeding on probing (P = 0.001), plaque index (P = 0.003), and gingival index (P = 0.003). The total level of IL-1β in GCF was significantly lower in the healthy group than in the groups with gingivitis and chronic periodontitis (P < 0.001). Salivary IL-1β levels showed significant differences across all three groups (P < 0.001). The level of MFG-E8 in GCF was higher in the healthy group than in the periodontal disease groups. Furthermore, there was no difference between gingivitis and periodontitis groups. The relationship between MFG-E8 and periodontal status should be further investigated.

Periodontal disease, peri-implant disease and levels of salivary biomarkers IL-1β, IL-10, RANK, OPG, MMP-2, TGF-β and TNF-α: follow-up over 5 years

OBJECTIVE

The aim of this study was to evaluate the levels of salivary biomarkers IL-1β, IL-10, RANK, OPG, MMP-2, TG-β and TNF-α in individuals with diagnosis of peri-implant mucositis in the absence or presence of periodontal and peri-implant maintenance therapy (TMPP) over 5 years.

MATERIAL AND METHODS

Eighty individuals diagnosed with peri-implant mucositis were divided into two groups: one group that underwent periodontal and peri-implant regularly maintenance therapy, called GTP (n=39), and a second group that received no regular maintenance GNTP (n=41). Each participant underwent a complete periodontal and peri-implant clinical examination. Collection of saliva samples and radiographic examination to evaluate peri-implant bone levels were conducted at two times: initial examination (T1) and after 5 years (T2). The salivary samples were evaluated through ELISA for the following markers: IL-1β, IL-10, RANK, OPG, MMP-2, TGF and TNF-α.

RESULTS

A higher incidence of peri-implantitis was observed in the GNTP group (43.9%) than in the GTP group (18%) (p=0.000). All individuals (n=12) who presented peri-implant mucositis and had resolution at T2 were in the GTP group. After 5 years, there was an increase in the incidence of periodontitis in the GNTP group compared to the GTP group (p=0.001). The results of the study revealed an increase in the salivary concentration of TNF-α in the GNTP group compared to the GTP group. The other salivary biomarkers that were evaluated did not show statistically significant differences between the two groups.

CONCLUSIONS

The salivary concentration of TNF-α was increased in individuals with worse periodontal and peri-implant clinical condition and in those with a higher incidence of peri-implantitis, especially in the GNTP group. Longitudinal studies in larger populations are needed to confirm these findings and elucidate the role of this biomarker in peri-implant disease.

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 Levels and Human Herpesviruses in Saliva from Clinical Periodontal Healthy Subjects with Peri-Implantitis: A Case-Control Study

This study evaluated the presence of cytokines (IL-1β, IL-2, IL-4, IL-6, MCP-1, MIP-1α, MIP-1β, and TNF-α) and human herpesvirus (HSV1, HSV2, EBV, CMV, VZV, HHV6, HHV7, and HHV8) in saliva samples taken from subjects with and without peri-implantitis. Forty-two periodontally healthy subjects were divided according to peri-implant condition: healthy and peri-implantitis groups. The clinical parameters as probing depth, clinical attachment level, plaque index, gingival bleeding, bleeding on probing, and suppuration were evaluated. For cytokine detection, multiplex analysis was performed, and PCR assay was used to identify herpesviruses. No significant differences were found in cytokine levels between groups (p > 0.05). The presence of herpesvirus was 1.97-fold higher in patients with peri-implantitis (odds ratio, CI 0.52-7.49). The association of the presence or absence of herpesvirus with the salivary markers was statistically significant for MIP-1β (p = 0.0087) and TNF-α (p = 0.0437) only in the peri-implantitis group. The presence of herpesviruses in patients with peri-implantitis suggests the development of a proinflammatory environment, which is characterized by increased expression of MIP-1β and TNF-α in saliva.

MIP-1α and MCP-1 as salivary biomarkers in periodontal disease

Aim

Chemokines released by different host cells when exposed to the components of periodontopathic bacteria induce and maintain an inflammatory response in the periodontium. The aim of the study was to estimate the salivary levels of two chemokines, macrophage inflammatory protein-1 alpha (MIP-1α) and monocyte chemo attractant protein-1 (MCP-1) in health, gingivitis and periodontitis and to evaluate their role as reliable salivary biomarkers in discriminating gingivitis and periodontitis from health.

Methods

A cross sectional study was designed to estimate the levels of MIP-1α and MCP-1 in whole unstimulated saliva from 75 patients who were divided into healthy (Group 1, n = 25), gingivitis (Group 2, n = 25) and chronic generalized periodontitis (Group 3, n = 25). MIP-1α and MCP-1 levels were estimated by using ELISA and were correlated with clinical parameters. ROC curve analysis was done to determine the sensitivity and specificity of these biomarkers in distinguishing periodontal disease from health.

Results

Both the biomarkers were detected in all the saliva samples. There was a statistically significant difference in the concentration of both the analytes in Group 3 and Group 2 compared with Group 1 (p < 0.001). ROC curve analysis showed 100% sensitivity and specificity for MIP-1α and MCP-1 in discriminating periodontitis from health. For discriminating gingivitis from health, MIP-1α had a higher sensitivity and specificity (100% & 88% respectively) compared to MCP-1(84.1% & 80% respectively).

Conclusion

There is a substantial increase in the concentration of both MIP-1α and MCP-1 with increasing severity of periodontal disease. Both the analytes showed promising results as biomarkers for discriminating periodontal disease from health.

Serum vitamin D levels and chronic periodontitis in adult, Caucasian population-a systematic review

The aim of this systematic review was to explore the relationship between serum vitamin D levels and periodontal disease. The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The focused PICO question was: Are serum vitamin D levels (I) associated with gingivitis or periodontitis (C) in healthy humans (P)? PubMed (Medline), Embase, Science Direct, the Cochrane library, and grey literature were searched up to 31 July 2017. Two reviewers independently selected studies and extracted data. Quality, risk of bias, and heterogeneity of the studies were assessed using the Newcastle-Ottawa Scale. In total, 365 studies were identified and 24 were analyzed. Seven studies fulfilled the inclusion criteria. Four case-control studies showed an influence of vitamin D and its metabolites on periodontal health status/disease. One interventional study suggested the proposed anti-inflammatory role of vitamin D. Two cross-sectional studies failed to show a relationship between vitamin D and periodontal condition. The literature on the effect of serum vitamin D levels on periodontal status remains scarce and controversial. Some data, however, support a "perio-protective" role for vitamin D. There is a need for well-designed randomized clinical trials to explore the possible anti-inflammatory effect of vitamin D on periodontal health.

32 and you - genetic testing for dental disorders

Genetic testing for serious illness and disease is becoming increasingly embedded in NHS healthcare. It can confirm a clinical diagnosis or guide therapy. Genetic testing for dental developmental disorders has moved beyond the realms of rarified grant-funded research groups and is now sufficiently rapid and affordable to be offered as part of a clinical service in some dental teaching hospitals. The first presentation of some genetic diseases may be in the dental surgery, so the family dentist should hone their diagnostic skills to identify patients who would benefit from referral to a genetics service. While diagnosis may sometimes guide treatment, there are now examples where it can even lead to cure. This article aims to describe some concepts and issues that a dentist should consider when referring for testing for a genetic dental disorder, and proposes that this subject area should be expanded in the dental undergraduate and postgraduate curricula in the UK.

Relationship between human immunodeficiency virus (HIV-1) infection and chronic periodontitis

INTRODUCTION

Current studies show that, even in the era of antiretroviral therapies, HIV-1 infection is associated with more severe and frequent refractory chronic periodontitis. Areas covered: This review, based on a systematic analysis of the literature, intends to provide an update on factors that may be involved in the pathogenesis of periodontal disease in HIV-1-infected patients, including local immunosuppression, oral microbial factors, systemic inflammation, salivary markers, and the role of gingival tissue as a possible reservoir of HIV-1. Expert commentary: The therapeutic revolution of ART made HIV-1 infection a chronic controllable disease, reduced HIV-1 mortality rate, restored at least partially the immune response and dramatically increased life expectancy of HIV-1-infected patients. Despite all these positive aspects, chronic periodontitis assumes an important role in the HIV-1 infection status for activating systemic inflammation favoring viral replication and influencing HIV-1 status, and also acting as a possible reservoir of HIV-1. All these issues still need to be clarified and validated, but have important clinical implications that certainly will benefit the diagnosis and management of chronic periodontitis in HIV-1-infected patients, and also contributes to HIV-1 eradication.

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.

Differentiation of Chronic and Aggressive Periodontitis by FTIR Spectroscopy

Without longitudinal clinical data, it is difficult to differentiate some cases of chronic periodontitis (CP) and aggressive periodontitis (AgP). Furthermore, both forms of disease are exacerbated by tobacco use. Therefore, this cross-sectional study was planned, primarily, to determine the ability of Fourier-transform infrared (FTIR) spectroscopy to distinguish CP and AgP patients by analysis of human saliva samples and, secondarily, to assess the potential confounding influence of smoking on discriminating disease-specific spectral signatures. FTIR spectra were collected from patients with a clinical diagnosis of CP (n = 18; 7 smokers) or AgP (n = 23; 9 smokers). Self-reported smoking status, which may be unreliable, was confirmed by salivary cotinine analysis. Spectral band area analysis and hierarchical cluster analyses were performed to clarify if the 2 periodontitis groups as well as smoker and nonsmoker patients could be differentiated from each other. Significant variations in lipid, amino acid, lactic acid, and nucleic acid content were found between nonsmoker CP and AgP groups. Although significantly lower lipid, phospholipid, protein, amino acid, lactic acid, and nucleic acid content was noted in the smoker AgP group compared with the nonsmoker AgP group, in the CP group, phospholipid, protein, amino acid, and lactic acid content was significantly lower for smokers compared with the nonsmokers. Based on these variations, nonsmoker CP and AgP patients were discriminated from each other with high sensitivity and specificity. Successful differentiation was also obtained for the smoker CP and AgP groups. Thiocyanate levels successfully differentiated smokers from nonsmokers, irrespective of periodontal status, with 100% accuracy. Differentiation of AgP and CP forms, concomitant with determination of smoking status, may allow the dental health professional to tailor treatment accordingly.