Bone remodeling biomarkers of periodontal disease in saliva

Evaluating salivary MMP-8 as a biomarker for periodontal diseases: A systematic review and meta-analysis

Objective

Periodontitis is the irreversible destructive process of the periodontium and is the major cause of tooth loss in adults worldwide. Diagnosis of early-stage periodontal disease is crucial for improving outcomes, and to this end, the application of indicator biomarkers is gaining interest. One such method involves measuring the level of matrix metalloproteinase-8 (MMP-8). This systematic review and meta-analysis aims to evaluate the salivary MMP-8 level of periodontitis and gingivitis cases compared to healthy controls.

Data

We evaluated all studies that compared different laboratory techniques for measuring salivary MMP-8 levels in periodontitis and gingivitis patients, alongside healthy controls.

Sources

The systematic search was performed on 10 October 2022 in three electronic databases.

Study selection results

Pooled mean differences (MD) were calculated with 95 % confidence intervals (CIs) between the researched groups. In addition, the correlation coefficient results between MMP-8 values and other clinical parameters were narratively summarized.Based on 20 eligible studies (n = 1725), patients with periodontitis presented significantly higher MMP-8 levels (MD = 273.26 ng/ml, CI: 194.42; 352.10). Similarly, patients with gingivitis presented significantly higher salivary MMP-8 levels than healthy individuals (MD = 122.82 ng/ml, CI: 64.19; 181.45) based on the results of 10 eligible studies (n = 704). Additionally, we found higher MMP-8 levels in periodontitis compared to gingivitis (MD = 112.04 ng/ml, CI: 56.15; 167.92). The correlation results suggest that salivary MMP-8 is associated with different clinical periodontal parameters.

Conclusion

Salivary MMP-8 level measurement may be a reliable method to distinguish between periodontal health and periodontal disease and also to distinguish between gingivitis and periodontitis.

Clinical significance

The measurement of salivary MMP-8 levels may have the potential to differentiate between periodontal health and disease reliably. Accordingly, it can be considered for integration into routine dental examinations as a quick and convenient method for the early detection and prevention of periodontitis, pending further validation.

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.

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.

The effect of interleukin-20 on periodontal tissue destruction in individuals with periodontitis

BACKGROUND AND OBJECTIVE

Periodontitis is an inflammatory disease that destroys periodontal tissues. Interleukin-20 (IL-20), on the other hand, is known as a potent angiogenic, chemotactic, and pro-inflammatory cytokine associated with various chronic inflammatory disorders. IL-20 has a significant role in the regulation of osteoclastogenesis and osteoblastogenesis. This study aimed to evaluate the effect of IL-20 on periodontal destruction.

METHODS

In this study, a total of 60 participants were included, 30 of whom were systemically and periodontally healthy (control group), and 30 were systemically healthy but had periodontitis (periodontitis group). Gingival crevicular fluid (GCF) and serum samples were collected from the participants for biochemical analysis. Enzyme-linked immunosorbent assay was used to determine the levels of IL-20, tumor necrosis factor (TNF)-α, IL1β/IL-10, RANKL/osteoprotegerin (OPG), and matrix metalloproteinase-8 (MMP8). For statistical analysis, the independent t-test, Pearson correlation coefficients, and the Chi-square test were used.

RESULTS

GCF IL-20, RANKL, RANKL/OPG, serum IL-20, RANKL, RANKL/OPG, MMP-8, TNF-α, IL-1B, and IL-1β/IL-10 values were found to be statistically significantly higher in the periodontitis group than in the control group. GCF OPG and serum IL-10 values were found to be statistically significantly higher in the control group than in the periodontitis group. No statistically significant difference was observed between the groups in serum OPG values. A statistically significantly positive correlation was observed between serum IL-20 value and serum RANKL, RANKL/OPG, MMP-8, TNF-α, IL-1β values, and periodontal clinical parameters. The ROC curves showed: AUC = 0.788 for GCF IL-20, and AUC = 1.000 for serum IL-20.

CONCLUSION

According to the results of the study, IL-20 was found to be associated with periodontitis. The role of IL-20 in periodontal pathogenesis is related to osteoclastogenesis and collagen degradation. It is conceivable that IL-20 may increase bone destruction by both affecting the RANKL/OPG ratio and proinflammatory cytokines.

Plasmon resonance biosensor for interleukin-1β point-of-care determination: A tool for early periodontitis diagnosis

Among pro-inflammatory cytokines, Interleukin-1β is crucially involved in several inflammatory-based diseases and even cancer. Increased Interleukin-1β levels in oral fluids have been proposed as an early marker of periodontitis, a broadly diffused chronic inflammatory condition of periodontal-supporting tissues, leading eventually to tooth loss. We describe the development of a portable surface-plasmon-resonance-based optical fiber probe suitably coated with an anti-Interleukin-1β antibody monolayer. A pico-nanomolar linear range of determination was obtained in both buffer solution and saliva with a rapid (3 min) incubation and high selectivity in presence of interferents. Higher Interleukin-1β concentration in the saliva of a periodontitis patient compared to a healthy control was determined. These measurements were validated by an automated ELISA system. Our results sustain the potential applicability of the proposed SPR-POF as diagnostic point-of-care device for real-time monitoring of salivary Interleukin-1β, that can support early detection of oral inflammatory-based pathologies and rapid and timely therapeutic decisions.

Soluble Receptor Activator of Nuclear Factor Ligand and Osteoprotegerin Levels in Gingival Crevicular Fluid among Cigarette Smokers and Non-smokers with and without Periodontitis

AIM

This study aimed to measure and compare the levels of soluble receptor activator of nuclear factor ligand (RANKL) and osteoprotegerin (OPG) in the gingival crevicular fluid (GCF), as well as their ratio, in smokers and nonsmokers with periodontitis.

MATERIALS AND METHODS

Gingival crevicular fluid samples were collected using PerioPaper strips, from 150 individuals, who were categorized into three groups: current smokers with periodontitis stage III grades C and B (n = 50), nonsmokers with periodontitis stages I and II grade A (n = 50), and control healthy individuals (n = 50). The concentrations (pg/mL) of sRANKL and OPG in the GCF were measured by enzyme-linked immunesorbent assays (ELISA).

RESULT

The smokers' group exhibited the highest sRANKL (pg/mL) concentration as a subsequent lead to a higher sRANKL/OPG ratio. The healthy control group exhibited higher OPG and lower sRANKL concentration, subsequently, the sRANKL/OPG ratio was reduced compared with the other study groups. However, there was no statistical significance of sRANKL and its relative ratio between periodontitis stage III grades C and B, periodontitis stages I and II grade A, and healthy control individuals. There was a statistically significant positive moderate correlation between smoking duration (years) and the sRANKL (pg/mL) concentration and a statistically significant negative moderate correlation between OPG (pg/mL) concentration and cigarettes smoked per day.

CONCLUSION

As a result, compared to the other research groups, smokers with periodontitis stage III grades C and B had greater GCF concentrations of sRANKL, lower OPG, and a higher sRANKL/OPG ratio. The difference in OPG (pg/mL) level was statistically significant. However, there was no statistically significant difference in sRANKL (pg/mL) or its relative ratio, sRANKL/OPG, across the groups.

CLINICAL SIGNIFICANCE

A characteristic that sets periodontitis apart is alveolar bone loss. Resorption is induced by RANKL and inhibited by OPG, resulting in a relative ratio. In light of this, the levels of RANKL and OPG may be helpful indicators for monitoring the activity of periodontal disease in both smokers and nonsmokers with and without periodontitis.

Saliva biomarkers in oral disease

Saliva is a versatile biofluid that contains a wide variety of biomarkers reflecting both physiologic and pathophysiologic states. Saliva collection is noninvasive and highly applicable for tests requiring serial sampling. Furthermore, advances in test accuracy, sensitivity and precision for saliva has improved diagnostic performance as well as the identification of novel markers especially in oral disease processes. These include dental caries, periodontitis, oral squamous cell carcinoma (OSCC) and Sjögren's syndrome (SS). Numerous growth factors, enzymes, interleukins and cytokines have been identified and are the subject of much research investigation. This review highlights current procedures for successful determination of saliva biomarkers including preanalytical factors associated with sampling, storage and pretreatment as well as subsequent analysis. Moreover, it provides an overview of the diagnostic applications of these salivary biomarkers in common oral diseases.

Protein-based salivary biomarkers for the diagnosis of periodontal diseases: Systematic review and meta-analysis

Objective

This systematic review and meta-analysis was aimed at determining differentially expressed protein-based biomarkers detectable in the saliva for the diagnosis of major periodontal diseases.

Methods

A literature review was conducted through January 31, 2022. The methodological quality and risk of bias were assessed with the Newcastle-Ottawa scale for case-control studies. Heterogeneity among studies was analysed with the Q statistical test and the I2 test. p-values lower than 0.10 and I2 values higher than 50% indicated high heterogeneity among studies; therefore, the random-effects model was used. The analysis of biological pathways associated with the differentially expressed protein markers was performed with the STITCH integration analysis tool and was limited to interactions with high confidence levels (0.7).

Results

Of all protein-based biomarkers detected, 12 were suitable for meta-analysis: IL-1β, MIP-1α, albumin, TNF-α, ICTP, Ig-A, lactoferrin, MMP-8, IL-6, IL-8, IL-17 and PGE2. The salivary markers with high applicability were IL-1β for differentiating patients with chronic periodontal disease from patients with gingivitis with an OE = 73.5 pg/mL; ICTP for differentiating patients with chronic periodontal disease from healthy control patients with an OE = 0.091 ng/mL; and PGE2 for differentiating patients with chronic periodontal disease from healthy control patients with an OE = 36.3 pg/mL.

Conclusions

The biomarkers with the highest differential expression and the greatest potential for clinical applicability are IL-1β for differentiating periodontitis from gingivitis, and ICTP and PGE2 for differentiating periodontitis from healthy status.

Is There a Similarity in Serum Cytokine Profile between Patients with Periodontitis or 2019-Novel Coronavirus Infection?-A Scoping Review

On 11 March 2020, the WHO declared a global emergency as a result of the 'novel coronavirus infection', which emerged from Wuhan, China, and rapidly spread across international borders. There is vast evidence that supports a direct link between oral cavities and this systemic circulation, but it is still unclear if oral conditions like periodontitis influenced the COVID-19 disease outcome. This scoping review highlights the fact that both periodontitis and COVID-19 independently increase serum pro-inflammatory cytokine levels, however there is a lack of documentation on if this biochemical profile synergizes with COVID-19 and/or periodontal severity in the same individuals. The purpose of this scoping review is to accumulate existing data on the serums IL-1β, IL-6, and TNF-α in COVID-19 and periodontitis patients and check if periodontitis negatively impacts the COVID-19 outcome, educating the population about the implications of COVID-19-related complications on their oral health, and vice versa, and motivating patients towards oral hygiene maintenance.

Inhibition of tumor necrosis factor receptor 1 and the risk of periodontitis

Aim

To investigate the effect of genetically proxied inhibition of tumor necrosis factor receptor 1 (TNFR1) on the risk of periodontitis.

Materials and methods

Genetic instruments were selected from the vicinity of TNFR superfamily member 1A (TNFRSF1A) gene (chromosome 12; base pairs 6,437,923-6,451,280 as per GRCh37 assembly) based on their association with C-reactive protein (N= 575,531). Summary statistics of these variants were obtained from a genome-wide association study (GWAS) of 17,353 periodontitis cases and 28,210 controls to estimate the effect of TNFR1 inhibition on periodontitis using a fixed-effects inverse method.

Results

Considering rs1800693 as an instrument, we found no effect of TNFR1 inhibition on periodontitis risk (Odds ratio (OR) scaled per standard deviation increment in CRP: 1.57, 95% confidence interval (CI): 0.38;6.46). Similar results were derived from a secondary analysis that used three variants (rs767455, rs4149570, and rs4149577) to index TNFR1 inhibition.

Conclusions

We found no evidence of a potential efficacy of TNFR1 inhibition on periodontitis risk.

TNFα, IL-6, miR-103a-3p, miR-423-5p, miR-23a-3p, miR-15a-5p and miR-223-3p in the crevicular fluid of periodontopathic patients correlate with each other and at different stages of the disease

Periodontitis is one of the main frequent intraoral diseases. Pathogenesis triggers are the immune responses with pro-inflammatory cytokines production and non-coding RNAs expression. The purpose of the present study was to evaluate the involvement of selected miRNAs in various stages of periodontitis and their relationship with the levels of inflammatory mediators in gingival crevicular fluid (GCF). For this study, 36 subjects (21 with periodontal disease, 15 healthy controls) were selected with an age mean of 59.1 ± 3.7 years. Clinical parameters included plaque index, gingival index, sulcus bleeding index, pocket depth, and clinical attachment level. The GCF samples were taken using capillary paper. The levels of miRNAs in GCF were estimated using a Real-Time PCR and TNFα and IL-6 levels were assessed by enzyme-linked immunosorbent assay (ELISA). The results indicated that the miRNA-103a-3p, miRNA-23a-3p, miRNA-15a-5p, and miRNA-223-3p were significantly upregulated with respect to healthy controls. Significant differences were observed for miRNA-23a-3p, miRNA-103a-3p and miRNA-423-5p levels in accord with the disease stages. Inflammatory mediators evaluated in GCF correlate well with the clinical parameters and the severity of the periodontal disease. miRNAs can represent biomarkers of disease stage and can be investigated as a possible therapeutic target, as well as levels of TNFα and IL-6 may drive the disease progression by acting as prognostic markers.

Clinical and Biochemical Effects of Smoking on Non-Surgical Periodontal Treatment in Grade III Stage C Periodontitis Patients

Objective: The purpose of this study was to evaluate the effect of smoking on clinical parameters and the serum and saliva levels of RANKL, OPG, and IL-34 in periodontitis stage III grade C (III-C) patients after non-surgical periodontal treatment (NSPT). Methods: A total of 60 subjects, 40 periodontitis-III-C patients (20 smokers and 20 non-smokers) and 20 non-smoker periodontally healthy individuals, were included. All clinical periodontal parameters were recorded, and unstimulated saliva and serum samples were collected from all patients at baseline, but at 1 and 3 months only from periodontitis patients (N=40). Saliva and serum levels of RANKL, OPG, and IL-34 were analyzed by ELISA. Results: At baseline only whole mouth probing depth (PD) and percent of sites with PD>5mm were higher in smokers than non-smoker periodontitis patients (p

The role of bone-specific biomarkers in chronic periodontitis diagnosis and treatment outcomes - a systematic review

Background The biomarkers of bone turnover may be vital for early detection of bone destruction in chronic periodontitis (CP). Lately, several new biochemical markers have been applied to estimate bone homeostasis.Objective The current review aims to evaluate the role of bone biomarkers in diagnosis and treatment outcomes of CP.Methods Literature search was conducted in databases like Medline (PubMed) and Scopus to include original research articles related to the role of bone biomarkers in CP. About 914 documents were identified through primary search, of which 11 original research articles were included.Results The most common bone biomarker applied in periodontal diagnosis was RANKL. Certain newer biomarkers like ICTP were also found to be useful in early detection of progressive CP.Conclusion The bone turnover biomarkers may serve as an adjunct to the traditional methods of periodontal diagnosis. They are vital in identifying the subjects at risk for future periodontal breakdown as well as in determining the therapeutic outcomes. Their applications in periodontal diagnosis is still in the developing stage and requires further investigation. With this background, the current systematic review evaluated the role of bone-specific biomarkers in CP diagnosis and treatment outcomes.

Effect of Salivary Exosomal miR-25-3p on Periodontitis With Insulin Resistance

Periodontitis is caused by an oral microbial dysbiosis-mediated imbalance of the local immune microenvironment, which is promoted by insulin resistance and obesity. The prevalence and severity of periodontitis is higher in patients with type 2 diabetes than in healthy individuals, possibly because of differences in immune responses. The level of glycemic control also affects the saliva profile, which may further promote periodontal disease in diabetes patients. Therefore, we compared the salivary exosomal miRNA profiles of patients with type 2 diabetes with those of healthy individuals, and we found that exosomal miR-25-3p in saliva is significantly enriched (by approximately 2-fold, p < 0.01) in obese patients with type 2 diabetes. We also identified CD69 mRNA as a miR-25-3p target that regulates both activation of γδ T cells and the inflammatory response. Knockdown of CD69 increased (by approximately 2-fold) interleukin-17A production of γδ T cells in vitro. To evaluate the role of exosomal miRNA on progression of periodontitis, we analyzed regional immune cells in both periodontal tissues and lymph nodes from mice with periodontitis. We found that diet-induced obesity increased the population of infiltrating pro-inflammatory immune cells in the gingiva and regional lymph nodes of these mice. Treatment with miR-25-3p inhibitors prevented the local in vivo inflammatory response in mice with periodontitis and diet-induced obesity. Finally, we showed that suppression of interleukin 17-mediated local inflammation by a miR-25-3p inhibitor alleviated (by approximately 34%) ligature-induced periodontal alveolar bone loss in mice. Taken together, these data suggest that exosomal miR-25-3p in saliva contributes to development and progression of diabetes-associated periodontitis. Discovery of additional miR-25-3p targets may provide critical insights into developing drugs to treat periodontitis by regulating γδ T cell-mediated local inflammation.

Relationship between Dynamics of TNF-α and Its Soluble Receptors in Saliva and Periodontal Health State

Soluble tumor necrosis factor receptors 1 and 2 (sTNF-R1 and sTNF-R2) are reported to protect against excessive TNF-α, a primary mediator of systemic responses to infection. This study aimed to investigate the levels of TNF-α, sTNF-R1, and sTNF-R2 in saliva and to verify whether their dynamics are associated with periodontal health. The study population comprised 28 adult patients. Probing pocket depth, clinical attachment level, and bleeding on probing were assessed, and periodontal inflamed surface area (PISA) was calculated. Stimulated saliva was collected before the oral examinations. The levels of TNF-α, sTNF-R1, sTNF-R2, and total protein (TP) in saliva samples were determined. There were significant positive correlations between TNF-α, sTNF-R1, and sTNF-R2 to TP (/TP) in stimulated saliva. Moreover, there were significant positive correlations between PISA and sTNF-R2/TP. Stepwise multiple regression analysis revealed that PISA was significantly associated with sTNF-R2/TP in saliva; however, TNF-α/TP was not significantly associated with PISA. In conclusion, this study demonstrates that significant relationships exist between the salivary levels of TNF-α and sTNF-R1, and that salivary sTNF-R2 is associated with the expansion of inflamed periodontal tissue.

Investigation of Salivary RANKL and OPG Levels in Periodontitis Patients at Hospital Universiti Sains Malaysia

Objective  This study was aimed to determine the levels of salivary receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) and its association with periodontal status among periodontitis patients.

Materials and Methods  A cross-sectional study was designed and performed at the Dental Clinic, Hospital Universiti Sains Malaysia (HUSM). Random sampling was employed to identify 88 participants into three groups: 30 mild periodontitis, 30 moderate to severe periodontitis, and 28 healthy (nonperiodontitis) patients. Periodontal parameters: periodontal pocket depth (PPD), clinical attachment level (CAL), plaque score (PS), and gingival bleeding index (GBI) were recorded. In total, 4 mL of unstimulated whole saliva was collected to determine the levels of salivary RANKL and OPG proteins by using ELISA technique. Data were analyzed by using SPSS software version 24.0.

Results  Mean values for PPD (5.3 ± 0.5) and CAL (5.6 ± 0.5) were observed higher for moderate to severe periodontitis as compared with values (4.4 ± 0.2) (4.5 ± 0.2) in mild periodontitis patients. The mean salivary RANKL and OPG was 0.23 ± 0.07 ng/mL and 1.78 ± 0.70 ng/mL respectively in moderate to severe periodontitis. Only salivary RANKL levels were significantly and positively correlated with all the clinical periodontal parameters.

Conclusion  The levels of salivary RANKL were higher as opposed to lower OPG levels in periodontitis patients in contrast to healthy (nonperiodontitis) patients. RANKL levels were significantly associated with the periodontal parameters. Therefore, we can conclude that RANKL can potentially aid as an adjunctive diagnostic protein in evaluating periodontal disease.

Identification of inflammation-related DNA methylation biomarkers in periodontitis patients based on weighted co-expression analysis

Evidence from past research has shown that DNA methylation plays a key role in the pathogenesis of periodontitis, regulating gene expression levels and thereby affecting the occurrence of various diseases. Three sample sets of methylation data and gene expression data were downloaded from Gene Expression Omnibus (GEO) database. A diagnostic classifier is established based on gene expression data and CpG methylation data. Abnormal expression of immune-related pathways and methyltransferase-related genes in patients with periodontitis was detected. A total of 8,029 differentially expressed CpG (DMP) was annotated to the promoter region of 4,940 genes, of which 295 immune genes were significantly enriched. The CpG sites of 23 differentially co-expressed immune gene promoter regions were identified, and 13 CpG were generally hypermethylated in healthy group samples, while some were methylated in most patients. Five CpGs were screened as robust periodontitis biomarkers. The accuracy in the training data set, the two external verification data sets, and in the transcriptome was 95.5%, 80% and 78.3%, and 82.6%, respectively. This study provided new features for the diagnosis of periodontitis, and contributed to the personalized treatment of periodontitis.

Evaluation of salivary biomarkers for the diagnosis of periodontitis

Background

Salivary interleukin (IL)-1β, matrix metalloproteinase (MMP)-8, pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) and Porphyromonas gingivalis (Pg) are related to periodontitis. This study aimed to investigate the diagnostic potential of these biomarkers and to build a prediction panel for diagnosing periodontal disease.

Methods

A total of 80 participants were enrolled in a cross-sectional study and divided into healthy (n = 25), gingivitis (n = 24), and periodontitis (n = 31) groups based on their periodontal exam results. A full mouth periodontal examination was performed and unstimulated saliva was collected. Salivary IL-1β, MMP-8, ICTP, and Pg were assessed using enzyme-linked immunosorbent assay (ELISA) and quantitative real time PCR (qPCR). Their potentials for diagnosing periodontal disease were analyzed and combined prediction panels of periodontal disease were evaluated.

Results

As a single marker, IL-1β showed the best diagnostic value of the four markers evaluated and exhibited an area under the curve (AUC) value of 0.88 with 90% sensitivity and 76% specificity for discriminating periodontitis subjects from healthy subjects, an AUC value of 0.80 with 83% sensitivity and 76% specificity for discriminating gingivitis subjects from healthy subjects and an AUC value of 0.66 with 68% sensitivity and 64% specificity for differentiating periodontitis subjects from gingivitis subjects. The combination of IL-1β, ICTP, and Pg exhibited the highest efficacy for discriminating periodontitis subjects from healthy subjects (AUC = 0.94) and gingivitis subjects (AUC = 0.77). The combination of IL-1β and MMP-8 exhibited the best ability to discriminate gingivitis from healthy subjects (AUC = 0.84).

Conclusions

Salivary IL-1β, MMP-8, ICTP, and Pg showed significant effectiveness for diagnosing periodontal disease. The combination of IL-1β, ICTP, and Pg can be used to discriminate periodontitis subjects from healthy subjects and gingivitis subjects, and the combination of IL-1β and MMP-8 can be used to discriminate gingivitis subjects from healthy subjects.

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.

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.

Salivary Biomarkers and Their Application in the Diagnosis and Monitoring of the Most Common Oral Pathologies

Saliva is a highly versatile biological fluid that is easy to gather in a non-invasive manner—and the results of its analysis complement clinical and histopathological findings in the diagnosis of multiple diseases. The objective of this review was to offer an update on the contribution of salivary biomarkers to the diagnosis and prognosis of diseases of the oral cavity, including oral lichen planus, periodontitis, Sjögren’s syndrome, oral leukoplakia, peri-implantitis, and medication-related osteonecrosis of the jaw. Salivary biomarkers such as interleukins, growth factors, enzymes, and other biomolecules have proven useful in the diagnosis and follow-up of these diseases, facilitating the early evaluation of malignization risk and the monitoring of disease progression and response to treatment. However, further studies are required to identify new biomarkers and verify their reported role in the diagnosis and/or prognosis of oral diseases.

Salivary Osteocalcin as Potential Diagnostic Marker of Periodontal Bone Destruction among Smokers

: The objective of the study was to assess the levels and diagnostic accuracy of salivary osteocalcin (OC), osteonectin (ON), and deoxypyridinoline-containing degradation fragment of the C-terminal telopeptide region of type I collagen (CTX) in adult smokers with periodontal bone destruction. Towards this, ninety systemically healthy patients (groups I: healthy, II: periodontitis with non-smokers, and III: periodontitis with current smokers) were included in the study. The results showed a positive correlation (weak to moderate) was observed for OC, ON, and CTX with probing pocket depth (PPD; r = 0.40, 0.32, and 0.36) and alveolar bone loss (BL; r = 0.58, 0.38, and 0.51) (p < 0.01). Smoker periodontitis was best discriminated from healthy controls using 15.25 ng/mL of OC (AUC: 0.870; 95% CI: 0.757-0.943; YI (Youden Index): 0.693; p < 0.0001). However, with a cut-off of BL at 33.33%, 19.24 ng/mL of salivary OC gave the best discrimination (AUC: 0.809; 95% CI: 0.686-0.900; Se: 80.0%; Sp: 73.47%, and YI: 0.534). A 16.45 ng/mL amount of OC gave excellent discrimination (AUC: 0.811; 95% CI: 0.688-0.901; Se: 92.31%; Sp: 65.22%, and YI: 0.575) among healthy and smoker periodontitis when PD at 6mm was considered as cut-off. Conclusion: The best discrimination between healthy controls and smoker periodontitis was obtained at 15.25 ng/mL of salivary OC.

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.

A. Diagnostic accuracy of salivary biomarkers of bone turnover in identifying patients with periodontitis in a Saudi Arabian population

BACKGROUND/PURPOSE

Salivary markers of bone turnover are useful biomarkers for screening patients advanced periodontal diseases with alveolar bone loss. Hence, the purpose of this study was to determine the diagnostic accuracy of deoxypyridinoline-containing degradation fragment of the C-terminal telopeptide region of type I collagen (CTX), Osteocalcin (OC) and Osteonectin (ON) in identifying patients with alveolar bone loss (BL) due to periodontitis.

MATERIALS AND METHOD

Salivary levels of CTX, OC and ON were evaluated in ninety patients (group I, II and III with healthy, periodontitis without Type2 diabetes mellitus-T2DM and periodontitis with T2DM respectively). Group III was included since T2DM is very common among patients attending our clinics. Bleeding on probing (BOP), probing pocket depth (PPD) and BL were recorded for these patients.

RESULTS

The concentrations of salivary CTX, OC, and ON were higher in subjects with periodontitis than in controls. Significant correlations were found between these biomarkers and periodontal parameters. CTX, OC, and ON could discriminate between healthy (group I) and diseased (group II & III) regarding BL with excellent sensitivity (90.2-100%) and good specificity (62.1-96.6%). ROC curve gave excellent discrimination regarding BL (AUC: 0.926-0.958) and PPD (AUC: 0.904-0.915). However, none of the cut-off values gave good discrimination regarding BOP.

CONCLUSION

It can be concluded that CTX, OC, and ON correlated well with BL and PPD. Among the three biomarkers, ON at 81.80 ng/ml gave the best discrimination for presence or absence of bone loss.

The interaction between serum amyloid A and Toll-like receptor 2 pathway regulates inflammatory cytokine secretion in human gingival fibroblasts

BACKGROUND

Serum amyloid A (SAA) has been identified to trigger inflammation response, and play a crucial role in chronic inflammatory diseases. However, the regulatory mechanism of SAA still remains unclear during the development of periodontitis METHODS: SAA mRNA and protein expression were detected in healthy and inflammatory gingival tissues using real-time polymerase chain reaction (PCR) and immunohistochemistry. Human recombinant SAA (Apo-SAA), Pam3CSK4 (a Toll-like receptor (TLR) 2 ligand), siRNA-SAA, or TLR2 neutralizing antibody was applied to treat human gingival fibroblasts, respectively, or combined. SAA, TLRs, and inflammatory cytokines interleukin (IL)-6 and IL-8 were analyzed by real-time PCR, western blotting, or enzyme-linked immunosorbent assay.

RESULTS

SAA expression increased in human inflammatory gingival tissues from patients with periodontitis (P <0.05). Apo-SAA could increase not only the mRNA expression of TLR2 (P <0.05), but also IL-6 and IL-8 mRNA and protein levels (P <0.05) which was suppressed by TLR2 antibody in human gingival fibroblasts. Pam3CSK4 increased SAA, IL-6, and IL-8 levels (P <0.05). However, the expression of SAA, IL-6, and IL-8 decreased after transfection of siRNA-SAA (P <0.05).

CONCLUSION

SAA not only increases in inflammatory gingiva, but also triggers inflammatory cytokine secretion via interacting with TLR2 pathway in human gingival fibroblasts, which indicates that SAA is involved in periodontal inflammation.

Inflammatory markers in the saliva of cerebral palsy individuals with gingivitis after periodontal treatment

The aim of this study was to evaluate the effect of periodontal treatment on the salivary cytokine levels and clinical parameters of individuals with cerebral palsy (CP) with gingivitis. A non-randomized, clinical trial was conducted in individuals diagnosed with spastic CP. Thirty-eight individuals were enrolled in the study and were categorized according to gingival index scores between 0-1 or 2-3, assigned to groups G2 or G1, respectively. Periodontal treatment comprised oral hygiene instructions, conventional mechanical treatment and 0.12% chlorhexidine applied as an adjunct. Clinical parameters and saliva samples were collected at baseline and at the 15-day follow-up visit. Bleeding on probing and periodontal screening and recording were determined. Non-stimulated saliva samples were obtained, and the salivary flow rate, the osmolality and the levels of cytokines IL-1β, IL-6, IL-8, IL-10, TNF-α and IL-12p70 were evaluated by a cytometric bead array. The Wilcoxon test, the Mann-Whitney test, Spearman correlation analysis, Poisson regression analysis and an adjusted analysis were performed (α = 0.05). The groups differed significantly in periodontal clinical parameters at baseline and at follow-up. Salivary flow rate and osmolality were similar in both groups at both timepoints. However, TNF-α and IL-1β levels were higher in G1 than in G2 at baseline. Mechanical treatment resulted in improved clinical parameters for both groups. Furthermore, mechanical treatment resulted in a significant reduction in salivary IL-1β and IL-8 levels for both groups after treatment. Periodontal treatment performed in individuals with CP and gingivitis reduces the levels of TNF-α, IL-1β, IL-6 and IL-8.

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.

The influence of glycyrrhetinic acid (enoxolone) toothpaste on periodontal treatment outcomes and salivary levels of IL-8, TNF-α, IL-17, MCP-1 and VEGF in patients with chronic periodontitis

This study evaluates the influence of glycyrrhetinic acid (enoxolone) toothpaste on the results of scaling and root planing as well as salivary levels of IL-8, TNF-α, IL-17, MCP-1 and VEGF in patients with chronic periodontitis. Clinical parameters and biomarkers of periodontitis were assessed longitudinally to determine response to the therapy. A 3-month case-controlled study of adults with chronic periodontitis was performed, with 18 patients receiving scaling and root planing and enoxlone toothpaste (group A) and 18 with scaling and root planing with regular toothpaste (group B). Clinical measurements of periodontal disease were recorded and saliva samples were collected at week 0 and 12. Samples were analyzed for immune markers: Interleukin-8 (IL-8), Tumor Necrosis Factor-α (TNF-α), Interleukin-17 (IL-17), Monocyte Chemoattractant Protein -1 (MCP-1) and Vascular Endothelial Growth Factor (VEGF). All parameters of periodontal health improved significantly in both groups by week 12 (p<0.01) with no significant differences between groups. However, improvements in group A were greater than in group B. IL-8, TNF-α, IL-17, MCP-1 and VEGF levels decreased significantly from baseline (p<0.01) in group A only. Salivary levels of IL-8, TNF-α, IL-17, MCP-1 and VEGF seem to reflect disease severity and response to therapy, suggesting their potential utility for monitoring periodontal disease status. Greater improvements of periodontal parameters and significant reduction of salivary biomarkers’ levels suggest potential benefits of glycyrrhetinic acid toothpaste in periodontal therapy.

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.

Mediators of Inflammation as a Link Between Diabetes Mellitus and Periodontal Breakdown

Our objective was to investigate immunological changes that occur in saliva of subjects with type 2 diabetes mellitus (T2DM) without signs of periodontal disease and to establish if salivary inflammatory cytokines are a possible link between diabetes mellitus and periodontal breakdown.

Material and methods. Twenty T2DM subjects with no periodontal disease and twenty healthy controls were registered for the present study. TNF-α and IL-6 level from saliva and serum were measured. Periodontal tissue samples were histologically examined.

Results: TNF-α and IL-6 levels were higher in T2DM subjects compared to controls, with an extremely significant difference in saliva (p<0.001). Significant inflammation, affecting both epithelial and connective tissues was present in periodontal biopsies.

Conclusions: The subjects showed an increased TNF-α and IL-6 levels, both in serum and -mostly in -saliva of diabetics without signs of periodontal disease, confirming the hypothesis of immunological implication, as a correlation between periodontal disease incidence and diabetes mellitus. Histologic alterations, suggesting a local inflammatory state, were present in periodontal tissue of diabetics, confirming the above hypothesis. The study reveals that saliva analysis is a quite efficient method in testing the periodontal breakdown progression in the subjects with T2DM.

Inflammatory Cytokines Interleukin-1β and Tumour Necrosis Factor-α - Novel Biomarkers for the Detection of Periodontal Diseases: a Literature Review

Objectives

The article aims to discuss the IL-1β and TNF-α potential use as salivary biomarkers of periodontal diseases pathogenesis and progression.

Material and Methods

This literature review has been registered in PROSPERO database with following number: CRD42016035729. Data investigation was performed on PubMed database as the main source of studies. The following search terms were used: “salivary biomarkers”, “periodontal diseases”, “TNF-alpha”, “Interleukin-1 beta”. Clinical trials and animal experimental models of periodontal disease were included in the discussion. In regards to inclusive dates, published studies from January 2006 to December 2015 were considered in this review along with the mentioned inclusion criteria.

Results

IL-1β and TNF-α salivary levels increased in diseased groups, they were associated with onset and disease severity, and their levels reduced in response to periodontal therapy. IL-1β and TNF-α could be promising biomarkers in the detection of periodontal diseases.

Conclusions

The use of a salivary cytokine-based diagnosis appears to be a screening method capable of diagnosing periodontal diseases in an early fashion, establishing an era of individualized clinical decisions.

Trends in Laboratory Diagnostic Methods in Periodontology

This work presents a summary of current knowledge on the laboratory diagnosis of periodontitis. It focuses on the theoretical foundations and is supplemented with new knowledge. It subsequently describes specifically the laboratory diagnosis methods of periodontitis: the protein expression of inflammation, oral microbiology and molecular diagnostics. Periodontitis is a serious disease worldwide and its confirmed association with systemic diseases means its severity is increasing. Its laboratory diagnosis has the potential to rise to the level of clinical and diagnostic imaging. The transfer of diagnostic methods from laboratory to clinical use is increasingly used in the prevention and monitoring of the exacerbation and treatment of periodontal disease, as well as of its impact on systemic disease.

Serum, saliva, and GCF concentration of RANKL and osteoprotegerin in smokers versus nonsmokers with chronic periodontitis

Background:

The role of host response in periodontitis pathogenesis is confirmed, and it is well established that immune response plays a major role in the alveolar bone destruction. In the investigation of these responses, the role of receptor activator of the nuclear factor-kB ligand (RANKL)-osteoprotegerin (OPG) system is the most promising. Smoking can affect the RANKL-OPG system in a manner that will further enhance bone loss in periodontitis. The aim of this study is to assess the serum, saliva, and gingival crevicular fluid (GCF) concentration of RANKL and OPG in smoker versus nonsmoker untreated chronic periodontitis (CP) patients.

Materials and Methods:

Thirty-nine subjects were included in the present cross-sectional study: 29 systemically healthy CP male patients (15 smokers, 14 nonsmokers) and 10 systemically and periodontally healthy nonsmoker male subjects. Serum, GCF, and whole saliva samples were obtained from the subjects. The enzyme-linked immunosorbent assay (ELISA) kits were used for assaying the concentrations of RANKL and OPG in the samples. The one-way analysis of variance (ANOVA) test and the least significant difference (LSD) post hoc test were utilized to compare differences between the groups.

Results:

RANKL and OPG concentrations in saliva, serum, and GCF did not show any significant difference among all groups (P > 0.05). Salivary RANKL/OPG ratios were significantly higher in the nonsmoker CP group than in the healthy control group (P > 0.05) but they were not statistically significant among smoker periodontitis patients.

Conclusions:

The salivary RANKL/OPG ratio was higher in nonsmokers with periodontitis in comparison with smoker periodontitis patients.

Associations Between Salivary Bone Metabolism Markers and Periodontal Breakdown

BACKGROUND

A dual relationship between glycemic status and bone remodeling was suggested recently. The present study aimed to 1) analyze salivary levels of receptor activator for nuclear factor κ-B ligand (RANKL), osteoprotegerin, osteocalcin, and osteopontin as potential biomarkers of alveolar bone loss and 2) determine whether the glycemic status affects the relationship between bone remodeling markers and periodontal status.

METHODS

Salivary levels of RANKL, osteoprotegerin, osteocalcin, osteopontin, and serum glycosylated hemoglobin A1c, insulin, and glucose were analyzed in 220 participants divided into four groups according to their periodontal health status: 1) 79 participants had at least 14 teeth with probing depth (PD) ≥4 mm (generalized periodontitis [GP]); 2) 65 participants had either two or seven teeth with PD ≥4 mm (two groups of localized periodontitis [LP1 and LP2, respectively]); and 3) 76 participants had no teeth with PD ≥4 mm (non-periodontitis control group).

RESULTS

Salivary concentrations of RANKL, osteocalcin, and osteopontin were higher, and osteoprotegerin was lower in females than in males. Salivary osteoprotegerin concentrations were higher in the GP and LP2 groups than in the control group, whereas RANKL, osteocalcin, and osteopontin were not related with periodontal status. Salivary osteopontin correlated positively with serum and salivary insulin. The association observed between increased osteoprotegerin concentrations and periodontitis was lost after salivary insulin was included into the analyses as a confounding factor.

CONCLUSIONS

Salivary concentrations of bone markers are either affected by glycemic status or detected at very low levels. These factors hinder their use as salivary biomarkers of periodontitis.

Estimation of salivary tumor necrosis factor-alpha in chronic and aggressive periodontitis patients

Introduction:

Periodontitis is a chronic bacterial infection characterized by persistent inflammation, connective tissue breakdown and alveolar bone destruction mediated by pro-inflammatory mediators. Tumor necrosis factor-alpha (TNF-α) is an important pro-inflammatory mediator that produced causes destruction of periodontal tissues.

Objective:

The aim of the study is to estimate the salivary TNF-α in chronic and aggressive periodontitis and control participants and further correlate the levels with clinical parameter such as gingival index (GI), plaque index (PI), probing pocket depth (PPD) and clinical attachment loss.

Materials and Methods:

The study population consisted of 75 subjects age ranging from 25 to 55 years attending the outpatient section of Department of Periodontics, Saveetha Dental College and Hospital. The study groups included Groups 1, 2, and 3 with participants with healthy periodontium (n = 25), generalized chronic periodontitis (n = 25) and generalized aggressive periodontitis (n = 25), respectively. Salivary samples from the participants were used to assess the TNF-α levels using enzyme-linked immunosorbent assay.

Results:

GI and PI were found to be significantly higher in chronic and aggressive periodontitis compared to the controls. The mean TNF-α value in chronic periodontitis patients (12.92 ± 17.21 pg/ml) was significantly higher than in control subjects (2.15 ± 3.60 pg/ml). Whereas, in aggressive periodontitis patients the mean TNF-α (7.23 ± 7.67) were not significantly different from chronic periodontitis or healthy subjects. Among periodontitis participants, aggressive periodontitis subjects exhibited a significant positive correlation between the salivary TNF-α and PPD.

Conclusion:

Salivary TNF-α levels are significantly higher in chronic periodontitis than in healthy subjects, but there was no significant correlation with the clinical parameters.

Point-of-care diagnosis of periodontitis using saliva: technically feasible but still a challenge

Periodontitis is a chronic inflammation of the periodontium caused by persistent bacterial infection that leads to the breakdown of connective tissue and bone. Because the ability to reconstruct the periodontium is limited after alveolar bone loss, early diagnosis and intervention should be the primary goals of periodontal treatment. However, periodontitis often progresses without noticeable symptoms, and many patients do not seek professional dental care until the periodontal destruction progresses to the point of no return. Furthermore, the current diagnosis of periodontitis depends on time-consuming clinical measurements. Therefore, there is an unmet need for near-patient testing to diagnose periodontitis. Saliva is an optimal biological fluid to serve as a near-patient diagnostic tool for periodontitis. Recent developments in point-of-care (POC) testing indicate that a diagnostic test for periodontitis using saliva is now technically feasible. A number of promising salivary biomarkers associated with periodontitis have been reported. A panel of optimal biomarkers must be carefully selected based on the pathogenesis of periodontitis. The biggest hurdle for the POC diagnosis of periodontitis using saliva may be the process of validation in a large, diverse patient population. Therefore, we propose the organization of an International Consortium for Biomarkers of Periodontitis, which will gather efforts to identify, select, and validate salivary biomarkers for the diagnosis of periodontitis.

Proinflammatory cytokine levels in oral lichen planus, oral leukoplakia, and oral submucous fibrosis

OBJECTIVES

The objective of this study was to identify salivary and serum concentrations of interleukin (IL)-8, IL-6, and tumor necrosis factor alpha (TNF-α) in patients with oral lichen planus, oral leukoplakia, oral submucous fibrosis, and healthy controls.

MATERIALS AND METHODS

Patients selected included 54 oral lichen planus (41 to 65 years), 50 oral leukoplakia (42 to 65 years), 51 oral submucous fibrosis (41 to 65 years), and 50 healthy controls (42 to 65 years). Oral lichen planus, oral leukoplakia, and oral submucous fibrosis cases were diagnosed using histopathological analysis. Salivary and serum cytokine concentrations were measured using enzyme-linked immunoassay kits in all subjects.

RESULTS

The levels of serum and salivary TNF-α, IL-6, and IL-8 were statistically significantly increased in oral leukoplakia, submucous fibrosis, and lichen planus in contrast to normal healthy subjects (P<0.05). Serum and salivary correlation analysis revealed strong and highly significant correlations for TNF-α, IL-6, and IL-8 in all groups (r=0.72-0.82, P<0.05).

CONCLUSION

Salivary and serum cytokines were also elevated when analyzed in oral precancerous lesions. Thus, salivary and serum IL-8, IL-6, and TNF-α levels might act as diagnostic markers for detection of oral precancer.

Targeted salivary biomarkers for discrimination of periodontal health and disease(s)

Generally, clinical parameters are used in dental practice for periodontal disease, yet several drawbacks exist with the clinical standards for addressing the needs of the public at large in determining the current status/progression of the disease, and requiring a significant amount of damage before these parameters can document disease. Therefore, a quick, easy and reliable method of assessing and monitoring periodontal disease should provide important diagnostic information that improves and speeds treatment decisions and moves the field closer to individualized point-of-care diagnostics.

OBJECTIVE

This report provides results for a saliva-based diagnostic approach for periodontal health and disease based upon the abundance of salivary analytes coincident with disease, and the significant progress already made in the identification of discriminatory salivary biomarkers of periodontitis.

METHODS

We evaluated biomarkers representing various phases of periodontitis initiation and progression (IL-1ß, IL-6, MMP-8, MIP-1α) in whole saliva from 209 subjects categorized with periodontal health, gingivitis, and periodontitis.

RESULTS

Evaluation of the salivary analytes demonstrated utility for individual biomarkers to differentiate periodontitis from health. Inclusion of gingivitis patients into the analyses provided a more robust basis to estimate the value of each of these analytes. Various clinical and statistical approaches showed that pairs or panels of the analytes were able to increase the sensitivity and specificity for the identification of disease.

CONCLUSIONS

Salivary concentrations of IL-1ß, IL-6, MMP-8, MIP-1α alone and in combination are able to distinguish health from gingivitis and periodontitis. The data clearly demonstrated a heterogeneity in response profiles of these analytes that supports the need for refinement of the standard clinical classifications if we are to move toward precision/personalized dentistry for the twenty-first century.

Inflammatory Mediators of Leprosy Reactional Episodes and Dental Infections: A Systematic Review

Reactional episodes in leprosy are a result of complex interactions between the immune system, Mycobacterium leprae, and predisposing factors, including dental infections. To determine the main inflammatory mediators in the immunopathological process of dental infections and leprosy reactions, we conducted a systematic review of primary literature published between 1996 and 2013. A three-stage literature search was performed (Stage I, "leprosy reactions" and "inflammatory mediators"; Stage II, "dental infections" and "inflammatory mediators"; and Stage III, "leprosy reactions," "dental infections," and "inflammatory mediators"). Of the 911 eligible publications, 10 were selected in Stage I, 68 in Stage II, and 1 in Stage III. Of the 27 studied inflammatory mediators, the main proinflammatory mediators were IL-6, IFN-γ, TNF-α, IL-1β, and IL-17; the main anti-inflammatory mediators were IL-10 and IL-4. Serum IL-6 and TNF-α concentrations were significant during periodontal and reactional lesion evolution; IFN-γ and IL-1β were associated with types 1 and 2 reactions and chronic periodontal disease. The proinflammatory mediators in dental infections and leprosy reactions, especially IL-6 and TNF-α, were similar across studies, regardless of the laboratory technique and sample type. IFN-γ and IL-1β were significant for leprosy reactions and periodontal diseases. This pattern was maintained in serum.

Salivary interleukin-6 in the detection of oral cancer and precancer

AIM

Oral cancer is a major health concern in many parts of the world. Despite its low survival rates, when detected early or in the precancer stage, it can drastically increase the survival rates. This strongly supports the need for sensitive biomarkers to perk up early detection of oral cancers. The aim of the study is to estimate whether salivary interleukin-6 (IL-6) can be used as a molecular marker to diagnose leukoplakia and oral squamous cell carcinoma (OSCC).

METHODS

The sample of 75 cases was divided into three groups of 25 patients each: group I: oral leukoplakia; group II: OSCC; group III: control group. Saliva samples were collected by simple drooling method and the concentration of IL-6 was determined by using ELISA (enzyme-linked immunosorbent assay) technique.

RESULTS

When the concentration of salivary IL-6 among the three groups was compared, the results were statistically significant ("P" value <0.001).

CONCLUSION

The increase in salivary IL-6 in leukoplakia and OSCC might point out its local production by the tumor cells. The difference in its levels between these two lesions might indicate the progression of precancer to cancer. Further longitudinal studies with increased sample size are needed to substantiate the utility of salivary IL-6 as diagnostic or prognostic marker for oral cancer and precancer.

Association study between salivary levels of interferon (IFN)-gamma, interleukin (IL)-17, IL-21, and IL-22 with chronic periodontitis

OBJECTIVE

To investigate if the salivary levels of IL-17, IL-21, IL-22, and its ratio regarding salivary IFN-γ may be linked with the periodontal clinical status.

DESIGN

One hundred and five chronic periodontitis (CP) subjects and 44 healthy controls (HC) were recruited. Periodontal status was assessed based on full-mouth clinical periodontal measurements. Cytokine salivary levels were analyzed by ELISA. The association between the analytes with CP was analyzed using a binary logistic regression model.

RESULTS

A statistically significant increase in salivary levels of IFN-γ and IFN-γ/IL-22 ratio in CP group could be detected, but there was no significant domination of any Th17 cytokine that could be of predictive value for health/disease status. Univariate and binary logistic regression analyses revealed a strong and independent association of IFN-γ salivary levels and IFN-γ/IL-22 ratio with disease status. An interaction effect of ageing on IFN-γ levels also could be noted.

CONCLUSION

While salivary levels of IFN-γ and IFN-γ/IL-22 ratio may act as strong/independent indicators of the amount and extent of periodontal breakdown, the low detection frequency of Th17 cytokines in saliva samples make these determinations useless for the detection of disease presence and/or its severity.

Proteomics - The research frontier in periodontics

Periodontitis is an inflammatory condition resulting from the interplay between the infectious agents and host factors. Various protein molecules play a vital role in the initiation, progression and severity of periodontal diseases. The study of proteins as biomarkers in periodontal diseases has been highlighted during the last few years. In periodontitis multiple bacteria derived (e.g. collagen degrading enzymes, elastase like enzymes etc) and host derived mediators (eg. PGE2, TNF, IL1, IL6, MMP's etc) expressed in the saliva and gingival crevicular fluid, can be utilized as diagnostic markers for the disease. Another significant development regarding human genes and proteins has been the discovery of potential new drugs for the treatment of periodontal diseases. Therefore the information of the proteins involved in the pathogenesis of periodontal diseases can be utilized for its diagnosis, prevention and treatment.