Protein biomarkers of periodontitis in saliva

Polymorphism of salivary proteins and risk of periodontal diseases: A systematic review and meta-analysis of clinical studies

OBJECTIVES

The present systematic review and meta-analysis aimed to assess the association between salivary protein polymorphisms and the risk of periodontal diseases (PD).

DATA

The review incorporated cross-sectional, case-control, retrospective/prospective cohort, and randomized controlled trials assessing the influence of salivary protein polymorphisms on the risk of PD development were included in this review.

SOURCES

A thorough literature search was conducted across electronic databases, namely PubMed, Scopus, Embase, and Web of Science, without any restrictions on publication language and year.

STUDY SELECTION

A total of 168 studies were identified, of which 19 were eligible for inclusion. The risk of bias (RoB) assessment of the included studies was conducted at the methodological level.

RESULTS

A total of 16 studies were included. Polymorphism in the gene encoding TNF-α was found to be protective against gingivitis, while those encoding IL-1α and IL-1β were associated with developing gingivitis. Of the 42 proteins investigated, various gene polymorphisms were identified as protective or risk factors for periodontitis. Protective genes include CFH, DNMT1, OPRM1, and TLR9. Conversely, certain salivary protein genes (e.g., CRP, ERN1, FAM5C, IDH2, LTA, TET2, MPA, NLRP3, TLR4) were associated with periodontitis risk. Notably, IL6, MMP9, and MUC7 genes showed no association with PD, while MMP13 was linked to early implant loss. Overall, the meta-analysis found a statistically significant association between salivary proteins' polymorphisms and risk of PD.

CONCLUSIONS

Salivary protein polymorphisms significantly influence PD, revealing protective and risk-associated genotypes. Despite limitations, findings suggest therapeutic targets, emphasizing the complex genetics-periodontal health interplay.

CLINICAL SIGNIFICANCE

This study unveils salivary protein polymorphisms as pivotal factors in PD. Protective genes including CFH and TLR9, and risk-associated genes including CRP and TLR4, indicate a genetic basis for PD susceptibility.

Does smoking influence tryptophan metabolism in periodontal inflammation? A cross-sectional study

OBJECTIVES

The aim of this study was to identify the effects of smoking and periodontal inflammation on tryptophan-kynurenine metabolism as well as the correlation between these findings and clinical periodontal parameters.

BACKGROUND

It has been shown that the tryptophan amino acid's primary catabolic pathway, the kynurenine pathway (KP), may serve as a key biomarker for periodontal disease. Although there are studies investigating the effect of smoking on KYN-TRP metabolism, the effect of smoking on periodontal disease through KP has not been revealed so far.

METHODS

The salivary and serum samples were gathered from 24 nonsmoker (NS-P) stage III, grade B generalized periodontitis and 22 smoker (S-P) stage III, grade C generalized periodontitis patients, in addition to 24 nonsmoker (NS-C) and 24 smoker (S-C) periodontally healthy control individuals. Saliva and serum IL-6, kynurenine (KYN), and tryptophan (TRP) values, and KYN/TRP ratio were analyzed by liquid chromatography-mass spectrometry. Clinical periodontal measurements were recorded.

RESULTS

Salivary TRP values were significantly higher in both periodontitis groups than control groups (p < .05). Salivary KYN values were highest in NS-P group (p < .05). Salivary KYN values did not differ significantly between periodontitis groups (p = .84). Salivary KYN/TRP ratio was significantly lower in NS-P group compared to other groups (p < .001). Serum TRP value is higher in S-P group than other groups; however, significant difference was found in S-C group (p < .05). Serum KYN values were significantly lower in smokers than nonsmokers. Serum KYN/TRP ratio is higher in NS-P group. NS-P group has the highest salivary IL-6 levels, NS-C group has the lowest values (p < .05).

CONCLUSIONS

Our results point out that smoking exacerbates inflammation in the periodontium and increases TRP destruction and decreases IDO activity by suppressing KP in serum. As a result, kynurenine and its metabolites may be significant biomarkers in the link between smoking and periodontal disease.

Antibacterial Properties of the Antimicrobial Peptide Gallic Acid-Polyphemusin I (GAPI)

A novel antimicrobial peptide, GAPI, has been developed recently by grafting gallic acid (GA) to polyphemusin I (PI). The objective of this study was to investigate the antibacterial effects of GAPI on common oral pathogens. This laboratory study used minimum inhibitory concentrations and minimum bactericidal concentrations to assess the antimicrobial properties of GAPI against common oral pathogens. Transmission electron microscopy was used to examine the bacterial morphology both before and after GAPI treatment. The results showed that the minimum inhibitory concentration ranged from 20 μM (Lactobacillus rhamnosus) to 320 μM (Porphyromonas gingivalis), whereas the minimum bactericidal concentration ranged from 80 μM (Lactobacillus acidophilus) to 640 μM (Actinomyces naeslundii, Enterococcus faecalis, and Porphyromonas gingivalis). Transmission electron microscopy showed abnormal curvature of cell membranes, irregular cell shapes, leakage of cytoplasmic content, and disruption of cytoplasmic membranes and cell walls. In conclusion, the GAPI antimicrobial peptide is antibacterial to common oral pathogens, with the potential to be used to manage oral infections.

Can the salivary urea and stimulated saliva concentration be a marker of periodontal diseases in opioid users? A case-control study

Introduction

& Aim: Microbial plaque is the primary cause of periodontal diseases, and smoking and opioid addiction can accelerate microbial plaque formation and disease progression. Adequate saliva flow and salivary urea concentration are important parameters for a healthy periodontium. In this study, the relationship between Periodontal Diseases and the History of opioid addiction was investigated by measuring the Salivary Urea and Stimulated Saliva Concentration.

Materials & methods

This case-control study was conducted on 240 patients (120 cases and 120 controls) in 2021 referred to addiction treatment centers and the dental clinic in Iran, Birjand. The control and case groups were matched in terms of age. Demographic, base data, and clinical examination results were collected by a checklist. Data were analyzed using SPSS 19 and one-way ANOVA and chi-square tests. P-value <0.05 was considered as the significance level.

Results

Periodontitis severity was significantly higher in the case group than in the control group (P-value = 0/000). Salivary urea concentration significantly increased in both case and control groups with an increase in periodontitis severity (P-value = 0/003 in the case group and P-value = 0/000 in the control group), but there was no significant relationship between the stimulated saliva flow rate and the severity of periodontitis in these two groups (P-value>0.05).

Conclusion

Following the use of opioids, the flow of saliva decreases, and with the exacerbation of the periodontal disease, the concentration of urea in saliva increases. Therefore, it seems that the analysis of saliva parameters, including urea concentration, can be useful for the diagnosis of periodontal disease, and saliva urea concentration is not directly related to opioid use.

Salivary leukocyte esterase activity by SillHa is a risk indicator of periodontal disease

BACKGROUND

There is increasing evidence that diagnostic salivary tests measuring inflammatory biomarkers are being developed to assess inflammatory status for early detection, prevention, and progression of periodontal disease. Therefore, the aim of the present study was to investigate and identify the salivary biomarker that can predict the inflammatory status of periodontal disease.

METHODS

A total of 36 patients (28 women and 8 men) with an average age of 57 years were investigated. Unstimulated saliva was collected from the recruited subjects and analyzed using SillHa, a saliva-testing device that measures bacteria count, saliva buffer capacity, acidity, leukocyte esterase, protein, and ammonia. Periodontal parameters were then obtained by clinical examination and initial periodontal therapy was performed. Data obtained with SillHa were compared with clinical periodontal parameters at baseline, re-examination (three months from baseline), and final examination (six months from re-examination).

RESULTS

Leukocyte esterase activity in saliva measured by SillHa; BOP and PCR measured by clinical examination showed a significant difference between baseline and final examination and between re-examination and final examination. Patients in the lower median group (group 1) had a significant difference in leukocyte esterase activity between baseline and final examination and re-examination and final examination. In addition, patients in Group 1 had significantly lower BOP between baseline and final examination. While patients in the higher median group (group 2) showed a modest decrease in leukocyte esterase activity, which was significant only between baseline and final examination, no significant changes were observed concerning BOP. Furthermore, the associated systemic disease was observed in 30% and 81.2% of group 1 and 2 patients, respectively.

CONCLUSION

The results suggest that leukocyte esterase activity in saliva measured by SillHa could serve as a reliable diagnostic marker for monitoring inflammatory status in periodontal disease.

Analysis of Salivary Levels of IL-1β, IL17A, OPG and RANK-L in Periodontitis Using the 2017 Classification of Periodontal Diseases-An Exploratory Observational Study

Periodontitis is a chronic disease with a high overall prevalence. It involves a complex interplay between the immune-inflammatory pathways and biofilm changes, leading to periodontal attachment loss. The aims of this study were (i) to assess whether the salivary IL-1β, IL-17A, RANK-L and OPG levels have the potential to discriminate between the mild and severe periodontitis conditions; and (ii) to enable diagnostic/prognostic actions to differentiate between distinct levels of the disease. The analysis of the clinical parameters and the evaluation of the salivary immunomediators levels by means of a multiplex flow assay revealed a statistically significantly higher level of IL-1β in the periodontitis III/IV patients, as well as a higher level of RANK-L in the periodontitis III/IV and I/II patients, when compared to the healthy controls. Furthermore, the grade C periodontitis patients presented a significantly higher level of RANK-L compared to the grade B and grade A patients. In the grade C patients, IL-1β had a positive correlation with the PPD and CAL indices and RANK_L had a positive correlation with CAL. The evidence emerging from this study associates the salivary IL-1β and RANK-L levels with an advanced stage of periodontitis, stage III/IV, and with grade C, suggesting the possible cooperative action of both in the inflammatory and bone loss events. In addition to IL-1β, RANK-L could be considered a combined diagnostic biomarker for periodontitis.

Modifiable and Non-modifiable Risk Factors Affecting Oral and Periodontal Health and Quality of Life in South Asia

Objectives:

The study aimed to review the prevalence of periodontal disease and associated factors among developing South Asian countries. The review was also aimed at providing an insight into how such factors play a role in affecting the Quality of life of patients with compromised oral health.

Background:

It has been observed that Oral health directly correlates with the Quality of life of an individual, so it is imperative to understand this, particularly in the developing parts of the world.

Methods:

A MeSH keyword search was carried out with the keywords: Periodontal diseases, Oral Health, Public Health, Asia, QoL, Quality of Life, Southeast Asia, Tobacco, and Risk Factors, and based on the findings, this detailed review was compiled.

Results:

The South Asian population forms 24.89% of the world population, while periodontal disease is an inflammatory condition that affects 11% of the globe. Several studies previously conducted across developing countries have shown that various factors like the socioeconomic status of an individual, smoking habit, consumption of alcohol, hypertension, history of diabetes, obesity, and stress are indirectly related to the onset of periodontal disease. Characteristics associated with specific populations like ethnicity, behavioral characteristics, and environmental factors may affect causing periodontitis.

Conclusion:

Dental practitioners in this region should consider risk factors that can be altered significantly to uplift the periodontal health status of an individual, which is not being considered in many developing countries.

Discovery, validation, and diagnostic ability of multiple protein-based biomarkers in saliva and gingival crevicular fluid to distinguish between health and periodontal diseases

Aim

To discover and validate differential protein biomarker expression in saliva and gingival crevicular fluid (GCF) to discriminate objectively between periodontal health and plaque‐induced periodontal disease states.

Materials and Methods

One‐hundred and ninety participants were recruited from two centres (Birmingham and Newcastle upon Tyne, UK) comprising healthy, gingivitis, periodontitis, and edentulous donors. Samples from the Birmingham cohort were analysed by quantitative mass spectrometry proteomics for biomarker discovery. Shortlisted candidate proteins were then verified by enzyme‐linked immunosorbent assay in both cohorts. Leave‐one‐out cross validation logistic regression analysis was used to identify the best performing biomarker panels.

Results

Ninety‐five proteins were identified in both GCF and saliva samples, and 15 candidate proteins were selected based upon differences discovered between the donor groups. The best performing panels to distinguish between: health or gingivitis and periodontitis contained matrix metalloproteinase‐9 (MMP9), S100A8, alpha‐1‐acid glycoprotein (A1AGP), pyruvate kinase, and age (area under the curve [AUC] 0.970); health and gingivitis contained MMP9, S100A8, A1AGP, and pyruvate kinase, but not age (AUC 0.768); and mild to moderate and advanced periodontitis contained MMP9, S100A8, A1AGP, pyruvate kinase, and age (AUC 0.789).

Conclusions

Biomarker panels containing four proteins with and without age as a further parameter can distinguish between periodontal health and disease states.

Characterization of Acidic Mammalian Chitinase as a Novel Biomarker for Severe Periodontitis (Stage III/IV): A Pilot Study

Periodontitis is a chronic inflammatory condition characterized by gingival infection, periodontal pocket formation, and alveolar bone loss. Acidic mammalian chitinase (AMCase), an active chitinase enzyme, increased its expression under severe inflammation and related systemic disorders. However, AMCase expression and molecular mechanism in periodontal inflammation, have not been elucidated yet. This study was aimed to characterize AMCase in severe periodontitis patients compare to those in periodontally healthy subjects. In total, 15 periodontally healthy subjects and 15 severe (stage III/IV) periodontitis patients were enrolled with their informed consent. Tissue samples were collected and analyzed using Western blot and enzyme-linked immunosorbent assay (ELISA). AMCase protein expressions in periodontal patients were significantly more increased than those of periodontally healthy individuals. ELISA resulted in median values (first quartile to third quartile) of the periodontally healthy group 0.654 ng/mL (range, 0.644−0.827 ng/mL) and the periodontitis group 0.965 ng/mL (range, 0.886−1.165 ng/mL). AMCase was expressed significantly higher levels in periodontitis patients than in periodontally healthy individuals (p < 0.05). This suggests that AMCase may play a potential role as a biomarker for the screening and early diagnosis of severe periodontitis.

Detection of Salivary miRNAs That Predict Chronic Periodontitis Progression: A Cohort Study

The aim of this two-year cohort study was to investigate salivary microRNAs (miRNAs) that predict periodontitis progression. A total of 120 patients who underwent supportive periodontal therapy were recruited. Unstimulated whole saliva was collected at baseline. Two years later, 44 patients were followed up (median age, 67.1 years) and divided into two groups: progression group (n = 22), with one or more sites with clinical attachment level (CAL) progression (>3 mm compared with baseline) or tooth extraction due to periodontitis progression; and the control group (n = 22), which did not exhibit CAL progression. In the microarray analysis of salivary miRNAs, hsa-miR-5571-5p, hsa-miR-17-3p, hsa-let-7f-5p, hsa-miR-4724-3p, hsa-miR-99a-5p, hsa-miR-200a-3p, hsa-miR-28-5p, hsa-miR-320d, and hsa-miR-31-5p showed fold change values <0.5 or ≥2.0 in the progression group compared with the control group (p < 0.05). On receiver operating characteristic curve analysis, areas under the curves of hsa-miR-5571-5p, hsa-let-7f-5p, hsa-miR-99a-5p, hsa-miR-28-5p, and hsa-miR-320d were >0.7, indicating fair discrimination power. The expressions of salivary hsa-miR-5571-5p, hsa-let-7f-5p, hsa-miR-99a-5p, hsa-miR-28-5p, and hsa-miR-320d were associated with periodontitis progression in patients with chronic periodontitis. These salivary miRNAs may be new biomarkers for progression of periodontitis, and monitoring them may contribute to new diagnostics and precision medicine for periodontitis.

Minimally Invasive Periodontology: A Treatment Philosophy and Suggested Approach

Severe periodontitis is a highly prevalent dental disease. With the advent of implant dentistry, teeth are often extracted and replaced. Periodontal surgery, where indicated, could also result in increased trauma to the patient. This literature review discusses different treatment modalities for periodontitis and proposes a treatment approach emphasizing maximum preservation of teeth while minimizing morbidity to the patient. Scientific articles were retrieved from the MEDLINE/PubMed database up to January 2021 to identify appropriate articles that addressed the objectives of this review. This was supplemented with hand searching using reference lists from relevant articles. As tooth prognostication does not have a high predictive value, a more conservative approach in extracting teeth should be abided by. This may involve repeated rounds of nonsurgical periodontal therapy, and adjuncts such as locally delivered statin gels and subantimicrobial-dose doxycycline appear to be effective. Periodontal surgery should not be carried out at an early phase in therapy as improvements in nonsurgical therapy may be observed up to 12 months from initial treatment. Periodontal surgery, where indicated, should also be minimally invasive, with periodontal regeneration being shown to be effective over 20 years of follow-up. Biomarkers provide an opportunity for early detection of disease activity and personalised treatment. Quality of life is proposed as an alternative end point to the traditional biomedical paradigm focused on the disease state and clinical outcomes. In summary, minimally invasive therapy aims to preserve health and function of the natural dentition, thus improving the quality of life for patients with periodontitis.

The Chairside Periodontal Diagnostic Toolkit: Past, Present, and Future

Periodontal diseases comprise a group of globally prevalent, chronic oral inflammatory conditions caused by microbial dysbiosis and the host immune response. These diseases specifically affect the tooth-supporting tissues (i.e., the periodontium) but are also known to contribute to systemic inflammation. If left untreated, periodontal diseases can ultimately progress to tooth loss, lead to compromised oral function, and negatively impact the overall quality of life. Therefore, it is important for the clinician to accurately diagnose these diseases both early and accurately chairside. Currently, the staging and grading of periodontal diseases are based on recording medical and dental histories, thorough oral examination, and multiple clinical and radiographic analyses of the periodontium. There have been numerous attempts to improve, automate, and digitize the collection of this information with varied success. Recent studies focused on the subgingival microbiome and the host immune response suggest there is an untapped potential for non-invasive oral sampling to assist clinicians in the chairside diagnosis and, potentially, prognosis. Here, we review the available toolkit available for diagnosing periodontal diseases, discuss commercially available options, and highlight the need for collaborative research initiatives and state-of-the-art technology development across disciplines to overcome the challenges of rapid periodontal disease diagnosis.

Mechanical biofilm disruption causes microbial and immunological shifts in periodontitis patients

Periodontitis is characterized by subgingival biofilm dysbiosis, inflammation and tissue destruction. Current treatment involves mechanical biofilm disruption known as non-surgical periodontal therapy (NSPT). This study sought to characterise the impact of treatment on microbial diversity and overall community, and the parallel impact on host inflammation in the oral cavity. Fourty-two periodontitis patients were included in this study, with periodontal clinical parameters, subgingival plaque and saliva samples collected at baseline and 90 days after treatment. Salivary cytokines were quantified, and subgingival plaque was analysed using 16S rRNA sequencing. After treatment, there were marked health-associated alterations in microbial composition and diversity, including differential abundance of 42 genera and 61 species. These changes were accompanied by substantial clinical improvement (pockets ≥ 5 mm, 27.50% to 9.00%, p < 0.001) and a decrease in salivary IL-1β (p < 0.001)-a putative marker of periodontal inflammation. Despite significant reductions in disease associated anaerobes, several genera (Fusobacterium, Prevotella, Tanenerella, Treponema) remained present and formed a distinct subnetwork associated with residual disease. Collectively, this study shows that current periodontal treatment results in partial restoration of a healthy microbial ecosystem, but features of biofilm dysbiosis and host inflammation remain in some patients, which were surprisingly independent of clinical response.

The potential impact of salivary peptides in periodontitis

Periodontitis is a complex immune-inflammatory condition characterized by the disruption of the periodontal ligament and subsequent formation of periodontal pockets, and by alveolar bone loss, often resulting in tooth loss. A myriad of factors, namely, genetic, metabolic, immunological, and inflammatory, is associated with progression of periodontitis. Periodontitis is also associated with systemic conditions such as neoplastic disorders, obesity, and diabetes. The current diagnosis of this disease relies on clinical measurements such as clinical attachment loss and probing depth, which have poor precision due to patient, operator and probe-related factors. Thus, there is a need to develop reliable, objective, and reproducible biomarkers for early diagnosis of periodontitis. In this regard, saliva, with contributions from the gingival crevicular fluid, holds great potential. However, most of the information on biomarkers of periodontium-related salivary proteins has come from studies on the molecular pathogenesis of periodontitis. In periodontitis, a more holistic approach, such as the use of -omics technologies, for biomarker discovery, is needed. Herein, we review the biomarkers proposed to date for the assessment of periodontitis, with emphasis on the role of salivary peptides in periodontitis and their assessment by high-throughput saliva proteomics. We also discuss the challenges pertaining to the identification of new periodontitis biomarkers in saliva.

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.

Salivary Small Extracellular Vesicles Associated miRNAs in Periodontal Status-A Pilot Study

This pilot study aims to investigate whether salivary small extracellular vesicle (sEV)-associated microRNAs could act as potential biomarkers for periodontal disease status. Twenty-nine participants (10 who were healthy, nine with gingivitis, 10 with stage III/IV periodontitis) were recruited and unstimulated whole saliva samples were collected. Salivary sEVs were isolated using the size-exclusion chromatography (SEC) method and characterised by morphology, EV-protein and size distribution using transmission electron microscopy (TEM), Western Blot and Nanoparticle Tracking Analysis (NTA), respectively. Ten mature microRNAs (miRNAs) in salivary sEVs and saliva were evaluated using RT-qPCR. The discriminatory power of miRNAs as biomarkers in gingivitis and periodontitis versus healthy controls was evaluated by Receiver Operating Characteristics (ROC) curves. Salivary sEVs were comparable to sEVs morphology, mode, size distribution and particle concentration in healthy, gingivitis and periodontitis patients. Compared to miRNAs in whole saliva, three significantly increased miRNAs (hsa-miR-140-5p, hsa-miR-146a-5p and hsa-miR-628-5p) were only detected in sEVs in periodontitis when compared to that of healthy controls, with a good discriminatory power (area under the curve (AUC) = 0.96) for periodontitis diagnosis. Our study demonstrated that salivary sEVs are a non-invasive source of miRNAs for periodontitis diagnosis. Three miRNAs that are selectively enriched in sEVs, but not whole saliva, could be potential biomarkers for periodontal disease status.

Evaluation of Salivary Cytokines and Vitamin D Levels in Periodontopathic Patients

Periodontal disease (PD) is an inflammatory condition of the tissues supporting the teeth, which is widespread among the adult population. Evidence shows a relationship between PD and vitamin D levels, which is involved in the regulation of bone metabolism, mineral homeostasis, and inflammatory response. This study aimed to perform a simultaneous evaluation of inflammatory mediators and vitamin D levels in saliva in periodontopathic patients to better understand their role in periodontal disease. In this observational study, clinical periodontal parameter examination was performed for each patient. Moreover, the saliva levels of 25(OH)D₃, TGFβ, IL-35, IL-17A, and MMP9 were evaluated using an ELISA assay. An increase in TGFβ, IL-35, MMP9, and IL-17A salivary levels and a reduction in 25(OH)D₃ levels were observed in periodontopathic patients with respect to the healthy controls. The present study revealed significant positive correlation between cytokines and highly negative correlation between 25(OH)D₃ and salivary cytokine levels. Further studies are needed to better understand if salivary cytokines and vitamin D evaluation may represent a new approach for detection and prevention of progressive diseases, such as PD.

[The content of vascular endothelial grow factor in saliva and serum in patients with periodontitis.]

To study the concentration of vasculoendothelial growth factor (VEGF) in mixed saliva and serum of patients in normal conditions and with generalized periodontitis. The main group (n = 42) was represented by patients with generalized periodontitis. The comparison group (n = 36) consisted of patients without periodontal tissue diseases. The concentration of VEFR was determined by the method of enzyme-linked immunosorbent assay (ELISA) using a commercial test-system "VEGF - IFA - BEST" (A-8784) ("Vector - Best", Russia). The median values VEFR in saliva were 5.49 times higher than the values for serum in the main group (p = 0.000000) and 7.01 times in the comparison group (p = 0.000000). The concentration of VEFR in the saliva of the examined main group exceeded the similar values of the comparison group (p = 0,014857); the median and interquartile range for the main group was 1098.45 (925.5; 1291) pg/ml, and for the comparison group 1360.5 (998.9; 2062) pg/ml. There were no differences in the serum VEFR concentration (p = 0.775124). No significant correlation was found between the serum VEFR content and the mixed saliva. The Spearman's rank correlation coefficient for the main group was R = 0,0184358, and for the comparison group, respectively, R = 0.188932. The source of VEFR in saliva are the glands and cells of the oral mucosa, and not the process of exudation from blood serum. The high content of VEFR in the saliva of healthy people and a decrease in its level during periodontitis indicates the important role of this protein in the processes of maintaining the normal state of periodontal tissues and reparation of tissues of the oral mucosa.

A Prototype Antibody-based Biosensor for Measurement of Salivary MMP-8 in Periodontitis using Surface Acoustic Wave Technology

Periodontitis is an economically important disease which is highly prevalent worldwide. Current diagnostic approaches are time-consuming and require interpretation of multiple aspects of clinical and radiographic assessment. Chair-side monitoring of inflammatory mediators of periodontitis could provide immediate information about disease activity, which can inform patient management. We aimed to develop a novel prototype biosensor to measure salivary matrix metalloproteinase-8 (MMP-8) using specific antibodies and surface acoustic wave (SAW) technology. The analytical performance of the prototype biosensor was compared to standard enzyme-linked immunosorbent assay (ELISA) using unstimulated saliva samples obtained from patients with periodontitis before and after non-surgical treatment (N = 58), patients with gingivitis (N = 54) and periodontally healthy volunteers (N = 65). Receiver operator characteristic (ROC) analysis for distinguishing periodontitis from health revealed an almost identical performance between the sensor and ELISA assays (area under curve values (AUC): ELISA 0.93; SAW 0.89). Furthermore, both analytical approaches yielded readouts which distinguished between heath, gingivitis and periodontitis, correlated identically with clinical measures of periodontal disease and recorded similar post-treatment decreases in salivary MMP-8 in periodontitis. The assay time for our prototype device is 20 minutes. The prototype SAW biosensor is a novel and rapid method of monitoring periodontitis which delivers similar analytical performance to conventional laboratory assays.

Salivary Interleukin 1-beta levels and clinical periodontal parameters in habitual naswar users and non-users

Objectives:

Aim of our study was to assess the expression of salivary Interleukin 1-beta (IL-1β) and clinical periodontal parameters in naswar users and non-users (controls).

Methods:

Eighty four individuals (forty-two naswar users and forty-two controls) were included in the study which was conducted between August 2017 and May 2018. Salivary IL-1β levels, plaque index (PI), bleeding on probing (BOP), probing depth (PD) and clinical attachment loss (CAL) was assessed in all the participants.

Results:

PD of 4mm (p<0.05), PD of 5-6mm (p<0.05), CAL (p<0.001) and levels of salivary IL-1β (p<0.05) were significantly higher among naswar users as compared to controls while PI, BOP and number of missing teeth showed no significant difference among the two groups (p>0.05).

Conclusion:

Periodontal inflammatory conditions were worse and salivary IL-1β levels were elevated in naswar users as compared to controls.

Detection of Salivary miRNAs Reflecting Chronic Periodontitis: A Pilot Study

The purpose of this cross-sectional pilot study was to find salivary microRNAs (miRNAs) reflecting periodontal condition in chronic periodontitis. One hundred and twenty chronic periodontitis patients (mean age, 68.4 years) participated in the study, from whom unstimulated whole saliva was collected. A multiphase study was conducted to explore salivary miRNAs as biomarkers of periodontitis. At first, a polymerase chain reaction (PCR) array was performed to compare salivary miRNAs profiles in no and mild (no/mild) and severe periodontitis patients. Next, the relative expression of salivary miRNAs on individual samples was assessed by real-time reverse transcription-PCR. The numbers (%) of patients were 26 (21.6%, no/mild), 58 (48.3%, moderate) and 36 (30.0%, severe), respectively. Among 84 miRNAs, only the relative expression of hsa-miR-381-3p in the severe periodontitis group was significantly higher than that of the no/mild periodontitis group (p < 0.05). Among the 120 patients, there was also a significant correlation between the relative expression of hsa-miR-381-3p and the mean probing pocket depth (PPD) (r = 0.181, p < 0.05). Salivary hsa-miR-381-3p was correlated with periodontitis condition in chronic periodontitis patients.

[The effect of probiotics on the secretory immunity of saliva in patients with type 2 diabetes]

To study the effect of the use of probiotics on the state of mucosal immunity in patients with type 2 diabetes. Evaluation of the results was carried out based on immunological parameters of the saliva of 50 patients suffering from type 2 diabetes with moderate periodontitis, before and 1 month after taking a probiotic complex based on Lactobacillus. In the salivary fluid of patients, a decrease in the concentration of pro-inflammatory cytokines IL-1β, TNF-α and IL-8 was noted, while an increase in the anti-inflammatory cytokine IL-10 was observed. An increase in local mucosal immunity was also observed, manifested in an increase in the synthesis of secretory immunoglobulin A.

B cell subset distribution is altered in patients with severe periodontitis

Several studies have recently highlighted the implication of B cells in physiopathogenesis of periodontal disease by showing that a B cell deficiency leads to improved periodontal parameters. However, the detailed profiles of circulating B cell subsets have not yet been investigated in patients with severe periodontitis (SP). We hypothesised that an abnormal distribution of B cell subsets could be detected in the blood of patients with severe periodontal lesions, as already reported for patients with chronic inflammatory diseases as systemic autoimmune diseases. Fifteen subjects with SP and 13 subjects without periodontitis, according to the definition proposed by the CDC periodontal disease surveillance work group, were enrolled in this pilot observational study. Two flow cytometry panels were designed to analyse the circulating B and B1 cell subset distribution in association with the RANKL expression. A significantly higher percentage of CD27⁺ memory B cells was observed in patients with SP. Among these CD27⁺ B cells, the proportion of the switched memory subset was significantly higher. At the same time, human B1 cells, which were previously associated with a regulatory function (CD20⁺CD69^-CD43⁺CD27⁺CD11b⁺), decreased in SP patients. The RANKL expression increased in every B cell subset from the SP patients and was significantly greater in activated B cells than in the subjects without periodontitis. These preliminary results demonstrate the altered distribution of B cells in the context of severe periodontitis. Further investigations with a larger cohort of patients can elucidate if the analysis of the B cell compartment distribution can reflect the periodontal disease activity and be a reliable marker for its prognosis (clinical trial registration number: NCT02833285, B cell functions in periodontitis).

Salivaomics: The current scenario

For generations, blood has been the medium of choice for diagnosing most diseases and conditions. The reason for this is mainly the limitations of technology. The concept of oral diagnostics is preferred to more invasive methods. In recent years, it has become evident that the salivary constituents become detectably altered in response to certain disease states. Even so, what is most impressive is that salivary biomarkers not only arise in correlation with oral disorders but also those of distal tissues and organs. This suggests that oral fluids may represent a substantial reservoir of molecular and microbial information capable of communicating the onset or presence of disease throughout the body. An initiative of the National Institute of Dental and Craniofacial Research created a roadmap to achieve these goals whereby, with the use of oral fluids as the diagnostic medium, it would become possible to scrutinize the health and/or disease status of patients. The real promise of salivary analysis use is the ability of the patient or clinician to directly and continuously assess disease status, progression and therapeutic efficacy. The sensitive analysis may even allow presymptomatic diagnosis. There are five major diagnostic alphabets available in saliva namely, proteins, messenger RNAs, micro-RNAs (mi-RNAs), metabolic compounds and microbes which offer substantial advantages for salivary diagnostics because, the state of the disease may be associated with detectable changes in one, but not all, dimensions. Recently, the Salivaomics Knowledge Base (SKB) has been established by aligning the salivary biomarker discovery. The SKB constitutes data repository, management system and web resource fabricated to support human salivary proteomics, transcriptomics, miRNA, metabolomics and microbiome research.

Influence of Type 2 Diabetes on Prevalence of Key Periodontal Pathogens, Salivary Matrix Metalloproteinases, and Bone Remodeling Markers in Sudanese Adults with and without Chronic Periodontitis

This study compared the influence of type 2 diabetes on the occurrence of six periodontal pathogens in plaque samples of patients with and without chronic periodontitis. Levels of salivary MMP-8, MMP-9, RANKL, and OPG were also investigated. The study enrolled 31 patients with type 2 diabetes and chronic periodontitis (DM + CP), 29 with chronic periodontitis (CP), and 20 with type 2 diabetes (DM). Questionnaire-guided interviews were conducted and plaque index, bleeding on probing, and pocket depth were recorded. Polymerase chain reaction (PCR) was utilized to determine the prevalence of the bacteria. The levels of salivary molecules were determined by enzyme immunosorbent assay (ELISA). The CP group had the highest prevalence of P. gingivalis (81.5%), followed by the DM + CP (59.3%) and DM (55.0%) groups (P > 0.05). Similar trends were observed for P. intermedia and T. denticola. The prevalence of T. forsythia was 100% in both periodontitis groups compared to 90% in the DM group. There were no significant differences between the groups regarding the concentrations of MMP-8, MMP-9, or OPG. RANKL concentrations were below the detection limit. Our data show that type 2 diabetes has no significant influence on the prevalence of the investigated periodontal pathogens, or the levels of salivary MMP-8, MMP-9, and OPG.

Salivary Antimicrobial Peptides in Early Detection of Periodontitis

In the pathogenesis of periodontitis, an infection-induced inflammatory disease of the tooth-supporting tissues, there is a complex interaction between the subgingival microbiota and host tissues. A periodontal diagnostic tool for detecting the initiation and progression of the disease, monitoring the response to therapy, or measuring the degree of susceptibility to future disease progression has been of interest for a long time. The value of various enzymes, proteins, and immunoglobulins, which are abundant constituents of saliva, as potential biomarkers has been recognized and extensively investigated for periodontal diseases. Gingival defensins and cathelicidins are small cationic antimicrobial peptides that play an important role in innate immune response. However, their applicability as salivary biomarkers is still under debate. The present review focuses on proteomic biomarkers and antimicrobial peptides, in particular, to be used at early phases of periodontitis.

Impact of nicotine on the interplay between human periodontal ligament cells and CD4+ T cells

Periodontitis is a common infectious disease associated with destruction of periodontal ligaments and alveolar bones. CD4(+) T cell-mediated immune response is involved in the progression of periodontitis. Tobacco consumption increases the risk of periodontal disease. However, the impact of nicotine on the interaction between human periodontal ligament (PDL) cells and CD4(+) T cells remains unrevealed. Our study aims to investigate the effect of nicotine on PDL cells and the cocultured CD4(+) T cells. The PDL cell cultures were established by explants from healthy individuals, exposed to nicotine or α-bungarotoxin (α-BTX), and incubated solely or in combination with CD4(+) T cells. Afterwards, cell viability, secreted cytokines, and matrix metalloproteinases (MMPs) were evaluated. In monoculture of PDL cells, nicotine dramatically repressed cell viability and increased apoptosis. Meanwhile, α-BTX largely reversed the nicotine-induced apoptosis and increased viability of PDL cells. Compared with the monoculture, MMP-1, MMP-3, interleukin (IL)-1β, IL-6, IL-17, and IL-21 in supernatant of cocultures were markedly elevated after treatment with nicotine. Moreover, α-BTX significantly attenuated nicotine-triggered production of these components either in mono- or co-cultures. In addition, PDL cell-derived CXCL12 following nicotine treatment recruited CD4(+) T cells. Above all, nicotine deteriorated periodontitis partially by promoting PDL cell-CD4(+) T cell-mediated inflammatory response and matrix degradation.

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.

[Variations in protein concentration and albumin/globulin ratio of whole unstimulated saliva obtained from healthy people and patients with chronic periodontitis]

OBJECTIVE

We detected and analyzed the clinical values of total protein (TP), albumin (ALB), globulin (GLB), and ALB/GLB ratio (A/G) of whole unstimulated saliva of healthy people to determine the time of day when saliva composition is relatively stable. We compared the protein concentration and A/G of whole unstimulated saliva of patients with chronic periodontitis with those of healthy volunteers to provide references for diagnostic methods and clinical applications of saliva.

METHODS

The whole saliva of 37 healthy subjects were collected at 8:00, 9:30, 11:30, 13:00, 16:30, and 21:00. Meanwhile, the whole saliva of 24 patients with periodontitis was collected in the morning. Bicinchoninic acid method was used to detect the TP content. Saliva ALB was detected by GF-D800 semi-automatic biochemical analyzer, and the GLB and A/G were calculated. Finally, the results were statistically analyzed using SPSS 19.0.

RESULTS

Salivary protein compositions were stable in the morning on an empty stomach. Healthy people: TP, (1 354.35±389.52) µg.mL-1; ALB, (139.55±27.19) µg.mL-1; GLB, (1 211.80±360.73) µg.mL-1; A/G, 0.126 3±0.041 7. Subjects with chronic periodontitis: TP, (2 611.56±231.62) µg.mL-1; ALB, (296.27±17.34) µg.mL-1; GLB, (2 315.69±221.67) µg.mL-1; A/G, 0.156 2±0.017 3. The contents of TP, ALB, and GLB in healthy individuals at different periods within a day showed significant differences (P<0.05), which were mainly reflected in the levels before and after meals. No significant difference was detected in A/G. The concentrations of TP, ALB, and GLB were significantly increased in patients with chronic periodontitis compared with those in healthy volunteers. However, no significant difference existed in A/G.

CONCLUSION

Salivary protein compositions are more stable in the morning than in other periods. Thus, mornings can be set as the time of specimen collection in future research. The concentrations of TP, ALB, and GLB in patients with chronic periodontitis are higher than those in healthy people.