Assessment of a novel screening test for neutrophil collagenase activity in the diagnosis of periodontal diseases

Prediabetes Associates with Matrix Metalloproteinase-8 Activation and Contributes to the Rapid Destruction of Periodontal Tissues

OBJECTIVE

 The aim of this cross-sectional study was to investigate the relationship between periodontitis, potential periodontitis oral fluid biomarkers, and prediabetes.

MATERIALS AND METHODS

 This study included 150 Greek adults aged 25 to 78 years who were tested with an Hemoglobin A1C (HBA1c) diagnostic system, an active-matrix metalloproteinase-8 (aMMP-8) point-of-care (PoC) test, and several salivary biomarkers enzyme-linked immunosorbent assay tests and gelatin zymography. A full-mouth clinical examination was performed to assess their periodontal and oral health status.

STATISTICAL ANALYSIS

 The Kruskal-Wallis test was used to determine the statistically significant difference in the levels of periodontal oral fluid biomarkers between the different periodontitis stages, periodontitis grades, and the stages and grades of periodontitis combined. Spearman's rank correlation was performed to assess the strength and direction of the association between aMMP-8 and HbA1c levels (<5.7 and ≥5.7%) and with the other oral fluid biomarkers among patients with severe periodontitis. A two-sided p-value below 0.05 was considered statistically significant in this study.

RESULTS

 aMMP-8, but not total MMP-8 or other biomarkers, associated significantly with the stage and grade of periodontitis combined (p < 0.001, Kruskal-Wallis test). Among stage III grade C periodontitis patients, aMMP-8 levels were significantly positively correlated with prediabetes (Spearman's rho = 0.646, p = 0.044), total MMP-8 (rho = 0.636, p = 0.048), PMN Elastase (rho = 0.729, p = 0.017), total MMP-9 (rho = 0.721, p = 0.019), and total MMP-8/TIMP-1 molar ratio (rho = 0.879, p < 0.001).

CONCLUSION

 Prediabetic disease development can upregulate MMP-8 expression (total MMP-8) in rapidly progressing, severe periodontitis, where MMP-8 latent species are further activated into their active forms (aMMP-8). Simultaneously, several proinflammatory biomarker levels are elevated in this tissue-destructive biomarker cascade. This development is easily detectable online/in real-time within 5 minutes by aMMP-8 PoC testing at the dentist's office.

aMMP-8 POCT vs. Other Potential Biomarkers in Chair-Side Diagnostics and Treatment Monitoring of Severe Periodontitis

This study aimed to compare several potential mouthrinse biomarkers for periodontitis including active matrix-metalloproteinase-8 (aMMP-8), total MMP-8, and other inflammatory biomarkers in diagnosing and monitoring the effects of nonsurgical periodontal therapy. Thirteen patients with stage III/IV periodontitis were recruited, along with thirteen periodontally and systemically healthy controls. These 13 patients were representative of the number of outpatients visiting any dentist in a single day. Full-mouth clinical periodontal parameters and biomarkers (the aMMP-8 point-of-care-test [POCT], total MMP-8, tissue inhibitor of MMPs (TIMP)-1, the aMMP-8 RFU activity assay, Myeloperoxidase, PMN elastase, calprotectin, and interleukin-6) were recorded at baseline and after nonsurgical therapy at 6 weeks. The aMMP-8 POCT was the most efficient and precise discriminator, with a cut-off of 20 ng/mL found to be optimal. Myeloperoxidase, MMP-8's oxidative activator, was also efficient. Following closely in precision was the aMMP-8 RFU activity assay and PMN elastase. In contrast, the total MMP-8 assay and the other biomarkers were less efficient and precise in distinguishing patients with periodontitis from healthy controls. aMMP-8, MPO, and PMN elastase may form a proteolytic and pro-oxidative tissue destruction cascade in periodontitis, potentially representing a therapeutic target. The aMMP-8 chair-side test with a cut-off of 20 ng/mL was the most efficient and precise discriminator between periodontal health and disease. The aMMP-8 POC test can be effectively used by dental professionals in their dental practices in online and real-time diagnoses as well as in monitoring periodontal disease and educating and encouraging good oral practices among patients.

In Vivo Regulation of Active Matrix Metalloproteinase-8 (aMMP-8) in Periodontitis: From Transcriptomics to Real-Time Online Diagnostics and Treatment Monitoring

BACKGROUND

This study investigated in vivo regulation and levels of active matrix metalloproteinase-8 (aMMP-8), a major collagenolytic protease, in periodontitis.

METHODS

Twenty-seven adults with chronic periodontitis (CP) and 30 periodontally healthy controls (HC) were enrolled in immunohistochemistry and transcriptomics analytics in order to assess Treponema denticola (Td) dentilisin and MMP-8 immunoexpression, mRNA expression of MMP-8 and its regulators (IL-1β, MMP-2, MMP-7, TIMP-1). Furthermore, the periodontal anti-infective treatment effect was monitored by four different MMP-8 assays (aMMP-8-IFMA, aMMP-8-Oralyzer, MMP-8-activity [RFU/minute], and total MMP-8 by ELISA) among 12 CP (compared to 25 HC).

RESULTS

Immunohistochemistry revealed significantly more Td-dentilisin and MMP-8 immunoreactivities in CP vs. HC. Transcriptomics revealed significantly elevated IL-1β and MMP-7 RNA expressions, and MMP-2 RNA was slightly reduced. No significant differences were recorded in the relatively low or barely detectable levels of MMP-8 mRNAs. Periodontal treatment significantly decreased all MMP-8 assay levels accompanied by the assessed clinical indices (periodontal probing depths, bleeding-on-probing, and visual plaque levels). However, active but not total MMP-8 levels persisted higher in CP than in periodontally healthy controls.

CONCLUSION

In periodontal health, there are low aMMP-8 levels. The presence of Td-dentilisin in CP gingivae is associated with elevated aMMP-8 levels, potentially contributing to a higher risk of active periodontal tissue collagenolysis and progression of periodontitis. This can be detected by aMMP-8-specific assays and online/real-time aMMP-8 chair-side testing.

Investigating the role of salivary Interleukin-40 levels in diagnosing periodontal diseases

BACKGROUND

The present study aimed to analyze IL-40, IL-1β, and MMP-8 levels in periodontitis as well as gingivitis and periodontal health, and to explore potential correlations between these biomarkers and standard clinical parameters.

MATERIALS AND METHODS

We collected saliva samples from 120 systemically healthy, non-smoking individuals aged between 18 and 63 years. These individuals were divided into three groups: healthy controls [S], gingivitis [G], and stage III grade B periodontitis [P]. IL-40, IL-1β, and MMP-8 levels in saliva samples were analyzed by ELISA.

RESULTS

We observed significantly elevated salivary IL-40 levels in the G group compared to the S group (p = 0.003). We found significantly higher salivary IL-1β levels in the P group compared to both the S and G groups (p = 0.000). Salivary MMP-8 levels were significantly higher in the P group than in the S group (p = 0.016).

CONCLUSION

Our study suggests that IL-40 and IL-1β may serve as effective salivary biomarkers for diagnosing gingivitis, while MMP-8 and IL-1β may be effective for distinguishing periodontitis. Based on our study's findings, it can be stated that IL-40 may serve as a new and effective biomarker for distinguishing individuals with gingivitis from healthy ones.

Active Matrix Metalloproteinase-8 (aMMP-8) Versus Total MMP-8 in Periodontal and Peri-Implant Disease Point-of-Care Diagnostics

Active matrix metalloproteinase-8 (aMMP-8) is a promising biomarker candidate for the modern periodontal and peri-implant disease diagnostics utilizing the chairside/point-of-care oral fluid technologies. These rapid biomarker analysis technologies utilize gingival crevicular fluid (GCF), peri-implant sulcular fluid (PISF), or mouth rinse as the oral fluid matrices that can be collected patient-friendly and non-invasively without causing bacteremia. aMMP-8, but not total or latent proMMP-8, has been shown to be a relevant biomarker to be implemented to the latest 2017 classification system of periodontitis and peri-implantitis. Thus, aMMP-8 point-of-care-testing (POCT)-but not total or latent proMMP-8-can be conveniently used as an adjunctive and preventive diagnostic tool to identify and screen the developing and ongoing periodontal and peri-implant breakdown and disease as well as predict its episodic progression. Similarly, aMMP-8 POCT provides an important tool to monitor the treatment effect of these diseases, but also other diseases such as head and neck cancer, where it can identify and predict the rapid tissue destructive oral side-effects during and after the radiotherapy. Additionally, recent studies support aMMP-8 POCT benefitting the identification of periodontitis and diabetes as the escalating risk diseases for COVID-19 infection. Overall, aMMP-8 POCT has launched a new clinical field in oral medicine and dentistry, i.e., oral clinical chemistry.

Quantification of oral neutrophil counts in periodontal health and disease utilising a standardised oral rinse

Background and Objectives

Polymorphonuclear neutrophils are the most abundant leukocytes in humans and are key host cells in defence against invading microorganisms. The oral neutrophil count may be an indicator of the periodontal health status, which correlates with the severity of periodontal disease. This study attempts to quantify orogranulocytes utilising an oral rinse and to assess the usefulness of this method in evaluating the oral inflammatory load much the same way the circulating neutrophils are used to screen for patients with infection in extra-oral sites.

Methods

A total of 125 participants were divided into five groups with 25 subjects in each group. The groups consisted of healthy, gingivitis, mild periodontitis, moderate periodontitis, and severe periodontitis. Participants were asked to rinse with 10 mL of 0.9% saline for 30 s and to expectorate. Samples were centrifuged at 2000 RPM for 10 min. The supernatant removed was suspended in 5 mL of Hanks's balanced salt solution. One millilitre of this suspension was mixed with 4 μL of acridine orange. A 10 μL aliquot of this suspension was then assessed on a haemocytometer, and the oral PMNs were counted using fluorescence microscopy.

Results

The mean number of oral neutrophils (100,000 cells/mL) was the lowest in the healthy group and increased in ascending order across the different groups with the highest for severe periodontitis group.

Conclusion

The oral neutrophil counts increased with the severity of periodontal inflammation. This is an easy, safe, reliable, and non-invasive method of quantification of oral neutrophils.

aMMP-8 point-of-care - diagnostic methods and treatment modalities in periodontitis and peri-implantitis

INTRODUCTION

When collected in a standardized fashion, oral fluid analysis can refine the diagnosis of periodontal and peri-implant disease. In practice, dental professionals can perform active matrix metalloproteinase (aMMP-8) analysis chairside.

AREAS COVERED

Periodontal tissues are mainly made up of type I collagen, and collagen breakdown is one of the main events in periodontal and peri-implantitis destructive lesions. In addition to traditional measurements, their diagnosis can be refined with tests utilizing oral fluids. The active matrix metalloproteinase-8 (aMMP-8) is possible to be determined from the gingival crevicular fluid (GCF), peri-implant sulcus fluid (PISF), and other oral fluids such as mouth rinse and saliva. We also investigated the applicability of aMMP-8 chair-side test kits in the evaluation of oral health benefits of different adjunctive host-modulating periodontal therapies including fermented lingonberry mouthwash (FLJ) and antibacterial photodynamic therapy (aPDT).

EXPERT OPINION

The aMMP-8 levels can more reliably detect early activation of periodontal and peri-implant disease as compared to traditional diagnostic methods that assess the experienced health status or past disease, rather than the present or future pathology. Novel therapies like, fermented lingonberry juice as a mouthrinse or aPDT, are potential host-modulating adjunctive treatments to reduce the signs of oral inflammation and infection.

An optical fiber-based point-of-care test for periodontal MMP-8 detection: a proof of concept

OBJECTIVES

The evaluation of salivary biomarkers has been proposed as a simple and non-invasive aid to the conventional periodontal diagnosis based on clinical-radiographic parameters. Matrix metalloproteinase-8 (MMP-8), especially in its active form, is considered one of the most reliable biomarkers of periodontitis, and point-of-care tests (POCTs) have been proposed for its clinical monitoring. In this proof-of-concept study, a novel highly sensitive POCT based on a plastic optical fiber (POF) biosensor exploiting surface plasmon resonance (SPR) to detect salivary MMP-8 is described.

METHODS

A SPR-POF biosensor was functionalized with a specific antibody to develop a surface-assembled monolayer (SAM) for the detection of total MMP-8. A white light source and a spectrometer connected to the biosensor were used to quantify MMP-8 level in both buffer and real matrix (saliva) by analysing the shift of the resonance wavelength determined by the specific antigen-antibody binding upon the SAM.

RESULTS

Dose-response curves by serial dilutions of human recombinant MMP-8 were realized, obtaining a limit of detection (LOD) of 40 pM (1.76 ng/ml) in buffer and 225 pM (9.9 ng/ml) in saliva and high selectivity compared to interferent analytes (MMP-2 and IL-6).

CONCLUSIONS

The proposed optical fiber-based POCT was able to detect and measure total MMP-8 with high selectivity and very low LOD in both buffer and saliva.

CLINICAL SIGNIFICANCE

The SPR-POF technology may be employed to create highly sensitive biosensors to monitor salivary MMP-8 levels. The possibility of specifically detecting its active, rather than total, form need to be further investigated. If confirmed and clinically validated, such a device may represent a promising tool to make an immediate, highly sensitive and reliable diagnosis of periodontitis, and to carry out a timely and targeted therapy, possibly helping to prevent the onset of local and systemic periodontitis-related complications.

A Comparative Analysis of Treatment-Related Changes in the Diagnostic Biomarker Active Metalloproteinase-8 Levels in Patients with Periodontitis

BACKGROUND

Previous studies have revealed the potential diagnostic utility of aMMP-8, an active form of MMP-8, in periodontal and peri-implant diseases. While non-invasive point-of-care (PoC) chairside aMMP-8 tests have shown promise in this regard, there is a dearth of literature on the evaluation of treatment response using these tests. The present study aimed to investigate treatment-related changes in aMMP-8 levels in individuals with Stage III/IV-Grade C periodontitis compared to a healthy control group, using a quantitative chairside PoC aMMP-8 test, and to determine its correlation with clinical parameters.

METHODS

The study included 27 adult patients (13 smoker, 14 non-smoker) with stage III/IV-grade C periodontitis and 25 healthy adult subjects. Clinical periodontal measurements, real-time PoC aMMP-8, IFMA aMMP-8, and Western immunoblot analyses were performed before and 1 month after anti-infective scaling and root planing periodontal treatment. Time 0 measurements were taken from the healthy control group to test the consistency of the diagnostic test.

RESULTS

Both PoC aMMP-8 and IFMA aMMP-8 tests showed a statistically significant decrease in aMMP-8 levels and improvement in periodontal clinical parameters following treatment (p < 0.05). The PoC aMMP-8 test had high diagnostic sensitivity (85.2%) and specificity (100.0%) for periodontitis and was not affected by smoking (p > 0.05). Treatment also reduced MMP-8 immunoreactivity and activation as demonstrated by Western immunoblot analysis.

CONCLUSION

The PoC aMMP-8 test shows promise as a useful tool for the real-time diagnosis and monitoring of periodontal therapy.

Validation of a Simplified Digital Periodontal Health Screening Module for General Dental Practitioners

As a silent disease, individuals at risk of periodontitis are not easily identified until the disease has become severe. Early detection at the community level is essential, especially for general dental practitioners. The aim of this study was to design a comprehensive, user-friendly tool to screen patients' periodontal health at community level and to evaluate users' acceptance of its use. The periodontal health screening module was first developed by an expert panel of periodontists, public health specialists and general dentists. The developed module was tested for content acceptance on 156 graduating dental students from three public schools and later validated by 12 private general dental practitioners (GDPs) for reliability. Most of the students (64.1%) found the new module an easy assessment tool for periodontal health compared to the Basic Periodontal Examination (BPE). Most claimed that they understand the contents (80.8%) and accepted the designs (86.6%) and agreed (82.7%) that the new assessment module would allow them to screen patients anytime in the clinic. The interrater reliability as assessed between the GDPs and the investigators revealed acceptable agreement ranging from 62.5-100.0% (mean 89.6 ± 10.2%). The simplified digital periodontal health screening module showed promising acceptance for application in private general dental clinics.

Validation of a noninvasive aMMP‐8 point‐of‐care diagnostic methodology in COVID‐19 patients with periodontal disease

Objectives

The aim of this study was to validate an active matrix metalloproteinase (MMP‐8) point‐of‐care diagnostic tool in COVID‐19 patients with periodontal disease.

Subjects, Materials, and Methods

Seventy‐two COVID‐19‐positive and 30 COVID‐19‐negative subjects were enrolled in the study. Demographic data were recorded, periodontal examination carried out, and chairside tests run for evaluating the expression of active MMP‐8 (aMMP‐8) in the site with maximum periodontal breakdown via gingival crevicular fluid sampling as well as via a mouth rinse‐based kit for general disease activity. In COVID‐19‐positive patients, the kits were run again once the patients turned COVID‐19 negative.

Results

The overall (n = 102) sensitivity/specificity of the mouthrinse‐based kits to detect periodontal disease was 79.41%/36.76% and that of site‐specific kits was 64.71%/55.88% while adjusting for age, gender, and smoking status increased the sensitivity and specificity (82.35%/76.47% and 73.53%/88.24, respectively). Receiver operating characteristic (ROC) analysis for the adjusted model revealed very good area under the ROC curve 0.746–0.869 (p < .001) and 0.740–0.872 (p < .001) (the aMMP‐8 mouth rinse and site‐specific kits, respectively). No statistically significant difference was observed in the distribution of results of aMMP‐8 mouth rinse test (p = .302) and aMMP‐8 site‐specific test (p = .189) once the subjects recovered from COVID‐19.

Conclusions

The findings of the present study support the aMMP‐8 point‐of‐care testing (PoCT) kits as screening tools for periodontitis in COVID‐19 patients. The overall screening accuracy can be further increased by utilizing adjunctively risk factors of periodontitis. The reported noninvasive, user‐friendly, and objective PoCT diagnostic methodology may provide a way of stratifying risk groups, deciding upon referrals, and in the institution of diligent oral hygiene regimens.

Ability of matrix metalloproteinase-8 biosensor, IFMA, and ELISA immunoassays to differentiate between periodontal health, gingivitis, and periodontitis

OBJECTIVE

The aim of this study was to determine the diagnostic utility of an MMP-8 biosensor assay in differentiating periodontal health from gingivitis and periodontitis and compare it with an established time-resolved immunofluorescence assay (IFMA) and enzyme-linked immunosorbent assay (ELISA).

BACKGROUND

Currently available antibody-based assays display a wide variability in their ability to accurately measure matrix metalloproteinase-8 (MMP-8) levels in saliva.

METHODS

Salivary MMP-8 levels were analyzed in 189 systemically healthy participants using an antibody-based biosensor prototype that operates using a surface acoustic wave technology and compared with IFMA and ELISA antibody assays. Participants were categorized into 3 groups: periodontal health (59), gingivitis (63), and periodontitis (67). A sub-population of participants (n = 20) with periodontitis received periodontal treatment and were monitored for 6 months.

RESULTS

All the assays demonstrated significantly higher salivary MMP-8 concentrations in participants with periodontitis versus gingivitis, periodontitis versus health, and gingivitis versus health (all p < .05). The biosensor data demonstrated significant correlations with IFMA (r = .354, p < .001) and ELISA (r = .681, p < .001). Significant reductions in salivary MMP-8 concentrations were detected by the biosensor (p = .030) and IFMA (p = .002) in participants with periodontitis 6 months after non-surgical periodontal treatment. IFMA had the best sensitivity (89.2%) for detecting periodontitis and gingivitis versus health and 96.6% for detecting periodontitis versus health and gingivitis. The biosensor had an AUC value of 0.81 and diagnostic accuracy of 74.2% for differentiating periodontitis and gingivitis from health; an AUC value of 0.86 and diagnostic accuracy of 82.8% for periodontitis versus health and gingivitis.

CONCLUSIONS

The biosensor, IFMA, and ELISA assays differentiated between periodontal health, gingivitis, and periodontitis based on salivary MMP-8 levels. Only the biosensor and, particularly, IFMA identified an effect of periodontal treatment in the participants with periodontitis. Our findings support the potential utility of salivary oral fluid aMMP-8-based point-of-care technology in the future of periodontal diagnostics.

Repeated Home-Applied Dual-Light Antibacterial Photodynamic Therapy Can Reduce Plaque Burden, Inflammation, and aMMP-8 in Peri-Implant Disease—A Pilot Study

Until now, in clinical dentistry, antibacterial photodynamic therapy (aPDT) has been restricted to in-office treatments, which hampers repeated applications. This pilot study tested the benefit of a commercially available Lumoral^® device designed for regular periodontal dual-light aPDT treatment at home. Seven patients with peri-implant disease applied dual-light aPDT daily in addition to their normal dental hygiene for four weeks. A single Lumoral^® treatment includes an indocyanine green mouth rinse followed by 40 J/cm² radiant exposure to a combination of 810 nm and 405 nm light. A point-of-care analysis of active-matrix metalloproteinase (aMMP-8), visible plaque index (VPI), bleeding on probing (BOP), and peri-implant pocket depth (PPD) measurements was performed on day 0, day 15, and day 30. Reductions in aMMP-8 (p = 0.047), VPI (p = 0.03), and BOP (p = 0.03) were observed, and PPD was measured as being 1 mm lower in the implant (p = ns). These results suggest a benefit of regular application of dual-light aPDT in peri-implantitis. Frequently repeated application can be a promising approach to diminishing the microbial burden and to lowering the tissue destructive proteolytic and inflammatory load around dental implants. Further studies in larger populations are warranted to show the long-term benefits.

Active MMP-8 point-of-care (PoC)/chairside enzyme-test as an adjunctive tool for early and real-time diagnosis of peri-implantitis

Objective

The aim of this study was to investigate the utility of the active matrix metalloproteinase (aMMP‐8)‐point‐of‐care (PoC) test as a quantitative real‐time chair‐side diagnostic tool for peri‐implant diagnosis, as well as assess the potentially developing and ongoing risk relative to the traditional clinical methods.

Background

Current peri‐implant and periodontal disease diagnoses rely on clinical and radiological examinations. This case‐control study investigated the applicability of aMMP‐8‐PoC immunotest for quantitative real‐time diagnosis and monitoring of dental implants in health and disease.

Methods

Sixty‐eight patients visiting a specialist clinic for maintenance following dental implant placement underwent assessment of their peri‐implant health. aMMP‐8‐PoC peri‐implant sulcular fluid (PISF) lateral‐flow immunotests were performed using ImplantSafe® technology quantitated by ORALyzer®. In addition, the PISF samples were analyzed for total MMP‐8, calprotectin, and interleukin (IL)‐6 by enzyme‐linked immunosorbent assays (ELISA), aMMP‐8 by western immunoblot, and MMP‐2 and MMP‐9 by gelatin zymography.

Results

The aMMP‐8‐PoC test promptly recorded and reflected peri‐implant disease, differentiating it clearly from health. X‐ray findings (bone loss > 2 mm), peri‐implant pocket depth ≥ 3 mm, and bleeding on probing were significantly more prevalent among implants positive for the aMMP‐8‐PoC test. aMMP‐8/ORALyzer analysis was more precise in recording disease than total MMP‐8, calprotectin, IL‐6, MMP‐2, and MMP‐9.

Conclusions

The aMMP‐8‐PoC test can be conveniently implemented to alert for and detect active collagenolysis affecting peri‐implant tissues, both in the early and advanced stages of the disease. Active and fragmented MMP‐8 exhibits a strong and significant association with peri‐implantitis as compared to total MMP‐8 and other biomarkers and can be utilized as the POC/chairside biomarker of choice in the new classification of peri‐implantitis.

Active MMP-8 Quantitative Test as an Adjunctive Tool for Early Diagnosis of Periodontitis

Periodontitis is a host-mediated bacterial disease that affects the tooth attachment apparatus. Metalloproteinase-8 (MMP-8), a validated biomarker, could aid in clinical diagnosis. This study aimed to evaluate the diagnostic performance of active (a) MMP-8 immunotest versus total (t) MMP-8 ELISA for quantitative real-time diagnosis and assessment of periodontitis severity at the site level. Gingival crevicular fluid (GCF) was sampled from 30 healthy, 42 mild, and 59 severe periodontitis sites from thirty-one volunteers. MMP-8 concentrations were determined by time-resolved immunofluorometric assay (IFMA) and enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using the STATA package. Both active and total MMP-8-based methods discriminated among sites according to periodontal diagnosis and severity, with a positive correlation between the two tests (p < 0.001). (a) MMP-8 models showed the best performance in receiver operating characteristic (ROC) curves to discriminate between healthy and periodontitis sites (area under the curve [AUC] = 0.89), while (t) MMP-8 demonstrated a high diagnostic precision in the detection of mild from severe periodontitis sites (AUC ≥ 0.80). The use of (a) MMP-8 and (t) MMP-8 could represent a useful adjunctive tool for periodontitis diagnosis and severity. These results support the applicability of new point-of-care methods in the monitoring of high-risk periodontal patients.

Active matrix metalloproteinase-8 (aMMP-8) point-of-care test (POCT) in the COVID-19 pandemic

INTRODUCTION

Active matrix metalloproteinase (aMMP)-8 utilized in point-of-care testing (POCT) is regarded as a potential biomarker for periodontal and peri-implant diseases. Various host and microbial factors eventually influence the expression, degranulation, levels and activation of aMMP-8. The type of oral fluids (saliva, mouthrinse, gingival crevicular, and peri-implant sulcular fluids [GCF/PISF], respectively) affect the analysis.

AREAS COVERED

With this background, we aimed to review here the recent studies on practical, inexpensive, noninvasive and quantitative mouthrinse and GCF/PISF chair-side POCT lateral flow aMMP-8 immunoassays (PerioSafe and ImplantSafe/ORALyzer) and how they help to detect, predict, monitor the course, treatment and prevention of periodontitis and peri-implantitis. The correlations of aMMP-8 POCT to other independent and catalytic activity assays of MMP-8 are also addressed.

EXPERT OPINION

The mouthrinse aMMP-8 POCT can also detect prediabetes/diabetes and tissue destructive oral side-effects due to the head and neck cancers' radiotherapy. Chlorhexidine and doxycycline can inhibit collagenolytic human neutrophil and GCF aMMP-8. Furthermore, by a set of case-series we demonstrate the potential of mouthrinse aMMP-8 POCT to real-time/online detect periodontitis as a potential risk disease for coronavirus disease 2019 (COVID-19). The clinical interdisciplinary utilization of aMMP-8 POCT requires additional oral, medical, and interdisciplinary studies.

An aMMP-8 Point-of-Care and Questionnaire Based Real-Time Diagnostic Toolkit for Medical Practitioners

The aim of this cross-sectional study is to propose an efficient strategy based on biomarkers adjunct with an interview/questionnaire covering risk factors for periodontitis for the identification of undiagnosed periodontitis by medical professionals. Active matrix metalloproteinase (aMMP)-8 levels in mouthrinse were analyzed by a point-of-care (PoC)/chairside lateral-flow immunotest, and salivary total MMP-8, total MMP-9 and calprotectin levels were analyzed by enzyme-linked immunosorbent assays (ELISAs) and active MMP-9 by gelatin zymography for 149 Greek patients. Patients underwent a full-mouth oral health examination for diagnosis according to the 2018 classification system of periodontal diseases. In addition, patient characteristics (risk factors: age, gender, education level, smoking and body mass index) were recorded. Receiver operating curve (ROC) analysis indicated better diagnostic precision to identify undiagnosed periodontitis for oral fluid biomarkers in adjunct with an interview/questionnaire compared with a plain questionnaire (i.e., risk factors): aMMP-8 AUC (95% confidence interval) = 0.834 (0.761-0.906), total MMP-8 = 0.800 (0.722-0.878), active MMP-9 = 0.787 (0.704-0.870), total MMP-9 = 0.773 (0.687-0.858) and calprotectin = 0.773 (0.687-0.858) vs. questionnaire = 0.764 (0.676-0.851). The findings of this study suggest that oral fluid biomarker analysis, such as a rapid aMMP-8 PoC immunotest, could be used as an adjunct to an interview/questionnaire to improve the precision of timely identification of asymptomatic, undiagnosed periodontitis patients by medical professionals. This strategy appears to be viable for referring patients to a dentist for diagnosis and treatment need assessment.

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

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

Low association between bleeding on probing propensity and the salivary aMMP-8 levels in adolescents with gingivitis and stage I periodontitis

BACKGROUND AND OBJECTIVE

Bleeding on probing (BOP) is a widely accepted measure used in periodontal diagnostics. Previous studies suggest that several factors can affect BOP propensity. The aim of this study was to investigate the relative impact of different local and modifying factors on BOP levels.

MATERIALS AND METHODS

The oral health of five hundred and forty-four adolescents (two birth cohorts) aged 15-17 years living in Kotka, Finland, was examined including periodontal probing depth, visible plaque index, root calculus, and BOP. Whole saliva samples were collected and measured for active matrix metalloproteinase-8 (aMMP-8) by time-resolved immunofluorometric assay (IFMA).

RESULTS

Bacterial plaque/calculus accumulation (oral hygiene) had a major influence on BOP levels. The relative impact was several times greater compared with the extent of periodontal pocketing, aMMP-8 levels, smoking, toothbrushing, or gender. Furthermore, BOP levels were significantly elevated among adolescents with poor oral hygiene than good oral hygiene even if adjusted for the extent of periodontal pocketing (P < .001). BOP levels could be low even if several ≥ 4 mm deep periodontal pockets existed. The difference in the extent of periodontal pocketing was not significant between the two birth cohorts of adolescents (P = .731).

CONCLUSIONS

BOP levels can be regarded as an important indicator of the extent of bacterial challenge and its adverse effects on the gingival inflammation. However, the level of oral hygiene may mask the association between the extent of gingival bleeding and the severity of the periodontal inflammatory condition. Thus, relying on BOP levels (below 10% or 20%) may provide insufficient information about the periodontal treatment need of an adolescent depending on his/her level of oral hygiene. Yet, more research is needed to confirm the results, also in adult populations.

Immune modulatory and antioxidant effects of locally administrated vitamin C in experimental periodontitis in rats

Background: Vitamin C is an important water-soluble vitamin with antioxidant and immune-modulatory actions. The aim of this study was to investigate the effects of locally applied vitamin C on alveolar bone resorption in rats with experimental periodontitis.Methods: Twenty-one male Sprague-Dawley rats divided into three groups with seven animals in each group: (1) control, (2) experimental periodontitis and 3) experimental periodontitis-local vitamin C treatment group. After ligature was removed, 50 μL vitamin C was locally administered into the subperiosteum of the buccal gingiva of periodontitis vitamin C (PvitC) group rats for three times in intervals of 2 days. At the end of the study, the animals were scarified, and serum and gingival samples were collected for analysis of serum IL-1β, oxidative stress index (OSI), CTX and malondialdehyde (MDA) levels and gingival MMP-8 immunostaining. Alveolar bone loss and attachment loss were determined based on measurements on histological sections obtained from rat mandibles.Results: Serum MDA and OSI levels which are related to the oxidative stress were significantly lower in the PvitC group as compared with those in the P group (p < .05). Serum CTX levels which are related to the bone resorption were significantly lower in the PvitC group as compared with those in the P group (p < .05). The numeric density of MMP-8-positive cells was significantly lower in the PvitC group compared to P group (p < .05). Alveolar bone loss and attachment loss were significantly lower in the PvitC group compared to P group (p < .05)Conclusions: The local vitamin C administration provided protection against inflammation-induced alveolar bone resorption by decreasing oxidative stress and inflammation-induced tissue breakdown vitamin C may be a therapeutic agent that can be used in periodontitis treatment.

Active Matrix Metalloproteinase-8 Point-of-Care (PoC)/Chairside Mouthrinse Test vs. Bleeding on Probing in Diagnosing Subclinical Periodontitis in Adolescents

This cross-sectional study compares the effectiveness of an active MMP-8 (aMMP-8) point-of-care (PoC)/chairside mouthrinse test to the conventional bleeding on probing (BOP) (cutoff 20%) test in detecting subclinical periodontitis/pre-periodontitis in Finnish adolescents. The study was carried out at the Kotka Health Center, Finland. A total of 47 adolescents (30 boys/17 girls) aged 15–17 were first tested with the aMMP-8 PoC test, followed by a full-mouth evaluation of clinical parameters of oral health including periodontal, oral mucosal, and caries assessment. A periodontist performed these clinical examinations. The aMMP-8 PoC test result had much stronger association with subclinical periodontitis than the BOP 20% test (2.8–5.3 times stronger in terms of odds ratio). The aMMP-8 PoC test had ≥2 times higher sensitivity than the BOP 20% test with, generally, the same specificity. Further, the aMMP-8 PoC test had generally better accuracy and lower false negative percentages. The aMMP-8 PoC test seemed to be more effective than the conventional BOP test in detecting subclinical periodontitis/pre-periodontitis in adolescents reducing the risk of their undertreatment. However, the sample size may be a limiting factor, and more studies are needed to confirm our results for both adolescents and adults.

Point-of-Care/Chairside aMMP-8 Analytics of Periodontal Diseases' Activity and Episodic Progression

Traditional periodontal disease diagnostics are based mainly on clinical examination and radiographs. They assess only past tissue destruction and provide no information on the current disease status or its future progression. The objective is to find out if an active matrix metalloproteinase-8 (aMMP-8) point-of-care (PoC) test could provide a cost-effective way to get around this limitation. This cross-sectional study used 47 adolescents and 70 adults, who were clinically examined and their aMMP-8 PoC tested. The aMMP-8 PoC test results and patients’ treatment need, based on the community periodontal index of treatment needs (CPITN), were compared and analyzed using Fisher’s exact test. In terms of CPITN, the aMMP-8 PoC test gave no false positives for both adolescents and adults. All healthy patients got a negative test result, while a positive test result indicated periodontal treatment need correctly. Finally, there was a significant association between a patient’s aMMP-8 PoC test result and his/her treatment need (p = 0.001 for adolescents, p = 0.001 for adults). In conclusion, more accurate diagnostics of periodontal diseases’ activity and progression using an aMMP-8 PoC test may help to reduce oral health care costs by reducing patient overtreatment, improving patient outcome, and reducing the need for complex periodontal therapy.

Matrix Metalloproteinase-8 as an Inflammatory and Prevention Biomarker in Periodontal and Peri-Implant Diseases

Levels of and especially the degree of activation of matrix metalloproteinase (MMP-8) in oral fluids (i.e., saliva, mouth rinse, gingival crevicular fluid (GCF) and peri-implantitis sulcular fluid (PISF)) increase to pathologically elevated levels in the periodontal and peri-implant diseases. This study aimed at collecting and collating data from previously published studies and determining whether active MMP-8 (aMMP-8) could serve as a biomarker for the diagnosis and prevention of periodontal and peri-implant diseases. The literature search identified a total of 284 articles. Out of 284 articles, 61 articles were found to be relevant. Data obtained from the selected studies were combined, and it indicated that aMMP-8 in oral fluids exerts the strong potential to serve as a useful adjunctive diagnostic and preventive biotechnological tool in periodontal and peri-implant diseases. aMMP-8 can be used alone or in combination with other proinflammatory and/or microbiological biomarkers.

The Ability of Quantitative, Specific, and Sensitive Point-of-Care/Chair-Side Oral Fluid Immunotests for aMMP-8 to Detect Periodontal and Peri-Implant Diseases

The analysis of the disease-specific oral and systemic biomarkers in saliva and oral fluids (i.e., mouth rinse, gingival crevicular fluid (GCF), and peri-implantitis fluid (PISF)) is demanding. Several hosts and microbial factors may influence their expression, release, and levels. The type of saliva/oral fluids utilized for the diagnostics affects the analysis. High sensitivity and specificities together with sophisticated methods and techniques are essential for valuable outcome. We describe here recently developed practical, convenient, inexpensive, noninvasive, and quantitative mouth rinse and PISF/GCF/chair-side/point-of-care (PoC) lateral-flow aMMP-8 immunoassays (PerioSafe and ImplantSafe/ORALyser) to detect, predict, and monitor successfully the course, treatment, and prevention of periodontitis and peri-implantitis, respectively. The tests have been independently and successfully validated to differentiate periodontal and peri-implant health and disease in Finland, Germany, Netherland, Sweden, Turkey, Nigeria, Malawi, and USA. The clinical use of salivary/oral fluid biomarkers to identify oral and systemic conditions requires additional studies utilizing these noninvasive screening, diagnostic, and preventive aMMP-8 PoC/chair-side technologies.

Influence of different forms and materials (zirconia or titanium) of abutments in peri-implant soft-tissue healing using matrix metalloproteinase-8: A randomized pilot study

STATEMENT OF PROBLEM

It is unclear how pathogenic bacteria adhere to different implant materials and whether biomarker matrix metalloproteinase-8 (MMP-8) level provides a reliable method of evaluating the connective tissue status of peri-implant tissues.

PURPOSE

The purpose of this pilot clinical study was to evaluate peri-implant connective tissue response by assessing the MMP-8 levels in peri-implant crevicular fluid around titanium and zirconia abutments.

MATERIAL AND METHODS

The study was designed as a prospective, within-subject comparison with left-right randomization low. Twelve participants with partial edentulism were selected according to inclusion and exclusion criteria. Peri-implant sulcal fluid sampling and pocket probing depths were assessed at 1, 3, and 12 months after placing the abutments. The MMP-8 protein level of the peri-implant sulcal fluid was determined by MMP-8-specific sandwich enzyme-linked immunosorbent assay system. The independent t test or Wilcoxon test was used to compare MMP-8 levels and probing depth assessment between the zirconia and titanium groups at different time points (1, 3, and 12 months). Repeated measures ANOVA was used for within-group comparison of the MMP-8 levels at 3 time points (α=.05).

RESULTS

At 1 and 3 months, the titanium abutments showed significantly higher MMP-8 levels and probing depths than the zirconia abutments (P<.05), but no significant differences were found at 12 months for either variable (P>.05).

CONCLUSIONS

This study suggests the presence of more remodeling and/or inflammatory phenomena around titanium implant abutments than around zirconia abutments of a different design during the early stages but not at 1 year.

Epithelial barrier and oral bacterial infection

The oral epithelial barrier separates the host from the environment and provides the first line of defense against pathogens, exogenous substances and mechanical stress. It consists of underlying connective tissue and a stratified keratinized epithelium with a basement membrane, whose cells undergo terminal differentiation resulting in the formation of a mechanically resistant surface. Gingival keratinocytes are connected by various transmembrane proteins, such as tight junctions, adherens junctions and gap junctions, each of which has a specialized structure and specific functions. Periodontal pathogens are able to induce inflammatory responses that lead to attachment loss and periodontal destruction. A number of studies have demonstrated that the characteristics of pathogenic oral bacteria influence the expression and structural integrity of different cell-cell junctions. Tissue destruction can be mediated by host cells following stimulation with cytokines and bacterial products. Keratinocytes, the main cell type in gingival epithelial tissues, express a variety of proinflammatory cytokines and chemokines, including interleukin-1alpha, interleukin-1beta, interleukin-6, interleukin-8 and tumor necrosis factor-alpha. Furthermore, the inflammatory mediators that may be secreted by oral keratinocytes are vascular endothelial growth factor, prostaglandin E2 , interleukin-1 receptor antagonist and chemokine (C-C motif) ligand 2. The protein family of matrix metalloproteinases is able to degrade all types of extracellular matrix protein, and can process a number of bioactive molecules. Matrix metalloproteinase activities under inflammatory conditions are mostly deregulated and often increased, and those mainly relevant in periodontal disease are matrix metalloproteinases 1, 2, 3, 8, 9, 13 and 24. Viral infection may also influence the epithelial barrier. Studies show that the expression of HIV proteins in the mucosal epithelium is correlated with the disruption of epithelial tight junctions, suggesting a possible enhancement of human papilloma virus infection by HIV-associated disruption of tight junctions. Altered expression of matrix metalloproteinases was demonstrated in keratinocytes transformed with human papilloma virus-16 or papilloma virus-18,. To summarize, the oral epithelium is able to react to a variety of exogenous, possibly noxious influences.

Peri-Implant Sulcus Fluid (PISF) Matrix Metalloproteinase (MMP) -8 Levels in Peri-Implantitis

INTRODUCTION

Matrix Metalloproteinase (MMP) -8 plays crucial role in pathogenesis of periodontitis and is also a possible biomarker candidate in peri-implantitis.

AIM

The aim of the study was to analyse MMP-8 levels in peri-Implant Sulcus Fluid (PISF) from peri-implantitis affected implants in smoking and non-smoking patients with different periodontal health status of natural teeth before and after peri-implantitis treatment.

SETTINGS AND DESIGN

Altogether 29 patients with peri-implantitis were recruited and divided into two study groups (11 with healthy periodontium or gingivitis, i.e. no marginal bone loss, and 18 with chronic periodontitis).

MATERIALS AND METHODS

PISF sample from one implant with peri-implantitis from each patient was collected at the baseline and six months after conservative and surgical peri-implantitis treatment, and clinical parameters were registered. Samples were analysed for MMP-8 with dento ELISA method applying a monoclonal antibody. Mucosal cell samples were also analysed for IL-1 gene polymorphism. PISF MMP-8 levels' differences between periodontal diagnosis groups and between smokers' and non-smokers' were analysed. Also, IL-1 polymorphism profiles were compared between study groups.

RESULTS

PISF MMP-8 levels were higher at the baseline compared to and after the treatment when all sampled implant sites were analysed together (p = 0.001). MMP-8 levels' distribution was broader in periodontitis patients' PISF samples, and only in periodontitis patients' group levels decreased statistically significantly after the treatment (p = 0.005). Smokers'and non-smokers' PISF MMP-8 was at similar level both at the baseline and after the treatment. No difference between distributions of IL-1 genotypes was found between study groups.

CONCLUSION

MMP-8 levels increase in peri-implantitis affected implants both in non-periodontitis and periodontitis patients, but levels still after treatment of the condition reflect intensified host response around implants and indicate challenges of controlling peri-Implantitis with any treatment modality.

Hydrogen Sulfide, Oxidative Stress and Periodontal Diseases: A Concise Review

In the past years, biomedical research has recognized hydrogen sulfide (H₂S) not only as an environmental pollutant but also, along with nitric oxide and carbon monoxide, as an important biological gastransmitter with paramount roles in health and disease. Current research focuses on several aspects of H₂S biology such as the biochemical pathways that generate the compound and its functions in human pathology or drug synthesis that block or stimulate its biosynthesis. The present work addresses the knowledge we have to date on H₂S production and its biological roles in the general human environment with a special focus on the oral cavity and its involvement in the initiation and development of periodontal diseases.

Salivary biomarkers in a biofilm overgrowth model

BACKGROUND

The purpose of this study is to determine whether baseline salivary inflammatory biomarkers could discriminate between different clinical levels of disease and/or detect clinical changes over a 3-week stent-induced biofilm overgrowth (SIBO) period.

METHODS

A total of 168 participants were enrolled in a 21-day experimental gingivitis investigation and grouped according to clinical measures of periodontal status of health and diseased individuals representing each of five biofilm gingival interface (BGI) periodontal groups: 1) health, all probing depth (PD) <3 mm and bleeding on probing (BOP) <10%; 2) gingivitis, all PD <3 mm and BOP ≥10%; 3) periodontitis (P)1, ≥1 site with PD >3 mm and BOP ≤10%; 4) P2, ≥1 site with PD >3 mm and BOP >10% but ≤50%; and 5) P3, ≥1 site with PD >3 mm and BOP >50%. Stents were used to prevent plaque removal during brushing over one maxillary and one mandibular posterior dental sextant for 21 days. Clinical periodontal parameters and unstimulated saliva were collected at screening, baseline, and each week during SIBO. Saliva samples were assessed for levels of 13 different biomarkers by multiplex immunoassay.

RESULTS

Higher salivary levels of interleukin (IL)-1β, matrix metalloproteinase (MMP)-3, MMP-8, MMP-9, and neutrophil gelatinase-associated lipocalin (NGAL) were found in diseased groups compared with the healthy group at baseline. Conversely, higher IL-1 receptor antagonist (ra) levels were found in healthy patients at baseline. In addition, during SIBO, MMP-1, tissue inhibitor of metalloproteinase (TIMP)-1, and TIMP-2 levels increased across all participant groups. A stepwise linear regression model using all salivary biomarkers demonstrated that, at baseline, increased IL-1ra (P = 0.004) and IL-6 (P = 0.009) were significantly associated with change in PDs during SIBO.

CONCLUSIONS

In summary, this investigation supports salivary levels of IL-1ra and IL-6 as potential indicators for PD changes during induced gingival inflammation. In addition, participants from the BGI-P3 group (severe periodontitis) demonstrated elevated baseline levels of IL-1β, MMP-3, MMP-8, MMP-9, and NGAL compared with the other study groups, strengthening the relevance of participants' biologic phenotype on expression of salivary biomarkers.

Quantifying oral inflammatory load: oral neutrophil counts in periodontal health and disease

BACKGROUND AND OBJECTIVE

Neutrophils are the primary white blood cells that are recruited to fight the initial phases of microbial infections. While healthy norms have been determined for circulating blood neutrophil counts in order to identify patients with suspected systemic infections, the levels of oral neutrophils (oPMNs) in oral health and in the presence of periodontal diseases have not been described. It is important to address this deficiency in our knowledge as neutrophils are the primary immune cell present in the crevicular fluid and oral environment and previous work has suggested that they may be good indicators of overall oral inflammation and periodontal disease severity. The objective of this study was to measure oPMN counts obtained in a standardized oral rinse from healthy patients and from those with chronic periodontal disease in order to determine if oPMN levels have clinical relevance as markers of periodontal inflammation. A parallel goal of this investigation was to introduce the concept of 'oral inflammatory load', which constitutes the inflammatory burden experienced by the body as a consequence of oral inflammatory disease.

MATERIAL AND METHODS

Periodontal examinations of patients with a healthy periodontium and chronic periodontal disease were performed (n = 124). Two standardized consecutive saline rinses of 30 s each were collected before patient examination and instrumentation. Neutrophils were quantified in the rinse samples and correlated with the clinical parameters and periodontal diagnosis.

RESULTS

Average oPMN counts were determined for healthy patients and for those with mild, moderate and severe chronic periodontal diseases. A statistically significant correlation was found between oPMN counts and deep periodontal probing, sites with bleeding on probing and overall severity of periodontal disease.

CONCLUSIONS

oPMN counts obtained through a 30-s oral rinse are a good marker of oral inflammatory load and correlate with measures of periodontal disease severity.

Salivary biomarkers: relationship between oxidative stress and alveolar bone loss in chronic periodontitis

OBJECTIVES

Oxidative stress is implicated in the pathogenesis of many systemic and oral diseases such as periodontal disease. The main aim of this study is to explore a possible association between salivary markers of OS and alveolar bone loss.

MATERIALS AND METHODS

The study included 20 patients with chronic periodontitis and 20 controls. Salivary OS biomarkers 8-hidroxy-desoxguanosine (8-HOdG), malondialdehyde (MDA), uric acid, total antioxidant capacity (TAC) and glutathione peroxidase (GPx) were evaluated. Bone loss markers such as C-terminal telopeptide of type I collagen (CTX I), matrix metalloproteinases-8 (MMP-8), osteocalcin and 25-hydroxy vitamin D3 (25- OH D) were detected in this study. The methods included general biochemical tests and ELISA.

RESULTS

Salivary 8-OHdG, MDA levels were significantly higher in the chronic periodontitis group compared with controls (p < 0.05). Salivary activities for uric acid, TAC and GPx were significantly decreased in patients with chronic periodontitis vs controls (p < 0.05). Salivary levels for CTX I, MMP-8, 25-OH D and Osteocalcin were significantly higher in the chronic periodontitis group compared to the controls (p < 0.05). A significant positive correlation was observed between salivary levels of MDA and CTX I. Significant negative correlations between uric acid and CTX I and between MMP-8 and uric acid have been found. Significant positive correlations were observed between CTX I, MMP-8, 25-OH D, osteocalcin and clinical parameters of periodontal disease.

CONCLUSIONS

Important oxidative stress associated with alveolar bone loss biomarkers can be detected in saliva of patients with periodontal disease.

Predictive, preventive, personalised and participatory periodontology: 'the 5Ps age' has already started

An impressive progress in dentistry has been recorded in the last decades. In order to reconsider guidelines in dentistry, it is required to introduce new concepts of personalised patient treatments: the wave of predictive, preventive and personalised medicine is rapidly incoming in dentistry. Worldwide dentists have to make a big cultural effort in changing the actual 'reactive' therapeutic point of view, belonging to the last century, into a futuristic 'predictive' one. The first cause of tooth loss in industrialised world is periodontitis, a Gram-negative anaerobic infection whose pathogenesis is genetically determined and characterised by complex immune reactions. Chairside diagnostic tests based on saliva, gingival crevicular fluid and cell sampling are going to be routinely used by periodontists for a new approach to the diagnosis, monitoring, prognosis and management of periodontal patients. The futuristic '5Ps' (predictive, preventive, personalised and participatory periodontology) focuses on early integrated diagnosis (genetic, microbiology, host-derived biomarker detection) and on the active role of the patient in which networked patients will shift from being mere passengers to responsible drivers of their health. In this paper, we intend to propose five diagnostic levels (high-tech diagnostic tools, genetic susceptibility, bacterial infection, host response factors and tissue breakdown-derived products) to be evaluated with the intention to obtain a clear picture of the vulnerability of a single individual to periodontitis in order to organise patient stratification in different categories of risk. Lab-on-a-chip (LOC) technology may soon become an important part of efforts to improve worldwide periodontal health in developed nations as well as in the underserved communities, resource-poor areas and poor countries. The use of LOC devices for periodontal inspection will allow patients to be screened for periodontal diseases in settings other than the periodontist practice, such as at general practitioners, general dentists or dental hygienists. Personalised therapy tailored with respect to the particular medical reality of the specific stratified patient will be the ultimate target to be realised by the 5Ps approach. A long distance has to be covered to reach the above targets, but the pathway has already been clearly outlined.

MMP-8 analysis in gingival crevicular fluid using ELISA and novel chair-side test

AIM: To validate accuracy of a novel chair-side test for matrix metalloproteinase (MMP)-8 as compared to enzyme-linked immunosorbent assay (ELISA) in Periodontal health and disease.

METHODS: Gingival crevicular fluid was collected from 150 subjects, Group 1 (healthy) - 50 subjects, Group 2 (gingivitis) - 50 subjects and Group 3 (chronic periodontitis) - 50 subjects. A chair-side test strip was indigenously prepared using polyclonal antibodies (principle of immunochromatography) to detect the MMP-8 levels. The detection accuracy (sensitivity and specificity) of the MMP-8 levels by chair-side test kit were compared with ELISA at baseline and 3 mo after scaling and root planing among the study population.

RESULTS: The novel chair side test detected MMP-8 levels in accordance with ELISA which at baseline were higher in Group 2 and Group 3 as compared to controls (P < 0.05), and these enzyme levels decreased after therapy (P < 0.05). The chair-side test could differentiate healthy, gingivitis and periodontitis. The detection accuracy of the chair-side test strip were on par with ELISA (sensitivity 92.9% and specificity of 100%) which were statistically significant (P < 0.05). A desire to arouse interest about periodontal health and maintenance in the Indian population provided a strong rationale for us to develop our chair-side test strips to suit our economy. Moreover, this was the first ever effort to develop and validate a chair-side test strip to detect MMP-8 levels in the Indian population. This test can be used on a large scale in private dental practice for the early detection of disease, tapping the sites at risk for disease, alongside helps in patient education and motivation for maintenance.

CONCLUSION: This study shows that the novel chair side test kit detects MMP-8 levels a biomarker of periodontal disease progression accurately making it a good chair side diagnostic tool. Further, it is cost effective and time saving which can make it applicable in private dental practice on a large scale for the early detection of periodontal disease.

Treponema denticola associates with increased levels of MMP-8 and MMP-9 in gingival crevicular fluid

OBJECTIVES

The aim was to assess the association between the presence of site-specific subgingival micro-organisms and the levels of matrix metalloproteinases-8 and matrix metalloproteinases-9 (MMP-8 and MMP-9) in gingival crevicular fluid (GCF).

MATERIALS AND METHODS

The patient group consisted of 56 subjects with periodontitis and the control group of 43 subjects without periodontitis. GCF samples from four test sites for each subject were collected. Polymerase chain reaction was used to detect the presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola. MMP-8 concentrations were analyzed by a time-resolved immunofluorometric assay, and MMP-9 levels were determined by enzyme-linked immunosorbent assay. Student's unpaired t-test, chi-square test, and Fisher's exact P-value were calculated.

RESULTS

The presence of T. denticola in the test sites was significantly higher in the patient group than in the control group. The presence of T. forsythia and T. denticola was associated with increased levels of MMP-8 in the test sites. Respectively, site-specific presence of T. denticola was associated with an increase in MMP-9 levels in three of the four test sites.

CONCLUSIONS

The presence of subgingival micro-organisms in GCF, particularly T. denticola, appeared to induce a host response with an increased release of MMP-8 and MMP-9 in the test sites.

Associations of periodontal microorganisms with salivary proteins and MMP-8 in gingival crevicular fluid

OBJECTIVE

We investigated in subjects with and without periodontitis, the levels of certain salivary proteins and matrix metalloproteinase-8 (MMP-8) in gingival crevicular fluid (GCF), in relation to the presence of specific periodontal pathogens.

METHODS

Clinical parameters were recorded at baseline, in 1985 and in 2009 from 99 subjects; 56 with and 43 without periodontitis (mean age 59.2 ± SD 2.9). Saliva samples collected in 2009 were analysed for salivary albumin, total protein and immunoglobulins A, G and M. GCF was collected for analysis of MMP-8 levels and for the PCR-analysis of the microorganisms Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola and Tannerella forsythia.

RESULTS

Periodontitis patients were more often infected by P. gingivalis (p < 0.05), P. intermedia and T. denticola (p = 0.01) than controls. Salivary albumin and protein concentrations were significantly higher in subjects with T. denticola (p < 0.05). MMP-8 levels were significantly higher in subjects with T. denticola (p < 0.001) and T. forsythia (p < 0.01). No corresponding results were found in salivary immunoglobulin concentrations.

CONCLUSION

The presence of T. denticola seemed to increase salivary albumin and total protein concentrations, and GCF levels of MMP-8. Both T. denticola and T. forsythia seemed to induce a cascade of host response with increased MMP-8 in GCF.

Matrix metalloproteinase-8 expression in periodontal tissues surgically removed from diabetic and non-diabetic patients with periodontal disease

BACKGROUND

Although it is known that periodontal matrix metalloproteinase-8 (MMP-8) expression is associated with periodontal disease, the information concerning the periodontal MMP-8 expression in diabetic patients with periodontal disease is insufficient.

MATERIALS AND METHODS

Periodontal tissue specimens were collected from seven patients without periodontal disease and diabetes (Group 1), 15 patients with periodontal disease alone (Group 2) and 10 patients with both periodontal disease and diabetes (Group 3). The frozen sections were prepared and MMP-8 protein expression was detected using immunohistochemistry and quantified. For in vitro study, human U937 mononuclear cells were pre-exposed to normal or high glucose and then treated with lipopolysaccharide (LPS).

RESULTS

The nonparametric Kruskal-Wallis test showed that the difference in MMP-8 protein levels among the three groups were statistically significant (p = 0.003). Nonparametric analysis using Jonckheere-Terpstra test showed a tendency of increase in periodontal MMP-8 levels across Group 1 to Group 2 to Group 3 (p = 0.0002). In vitro studies showed that high glucose and LPS had a synergistic effect on MMP-8 expression.

CONCLUSION

Our current study showed an increasing trend in MMP-8 protein expression levels across patients without both periodontal disease and diabetes, patients with periodontal disease alone and patients with both diseases.

What do 'omic technologies have to offer periodontal clinical practice in the future?

BACKGROUND AND OBJECTIVE

Periodontal diseases are the most common chronic inflammatory diseases of humans and a major cause of tooth loss. Inflammatory periodontitis is also a complex multifactorial disease involving many cell types, cell products and interactions. It is associated with a dysregulated inflammatory response, which fails to resolve, and which also fails to re-establish a beneficial periodontal microbiota. There is a rich history of biomarker research within the field of periodontology, but exemplary improvements in analytical platform technologies offer exciting opportunities for discovery. These include the 'omic technologies, such as genomics, transcriptomics, proteomics and metabolomics, which provide information on global scales that can match the complexity of the disease. This narrative review focuses on the recent advances made in in vivo human periodontal research by use of 'omic technologies.

MATERIAL AND METHODS

The Medline database was searched to identify articles currently available on 'omic technologies with regard to periodontal research.

RESULTS

One hundred and sixty-one articles focusing on biomarkers of and 'omic advances in periodontal research were analysed for their contributions to the understanding of periodontal diseases.

CONCLUSION

The data generated by the use of 'omic technologies have huge potential to inform paradigm shifts in our understanding of periodontal diseases, but data management, analysis and interpretation require a thoughtful and systematic bioinformatics approach, to ensure meaningful conclusions can be made.

Effect of 1,064-nm Nd:YAG laser therapy on GCF IL-1β and MMP-8 levels in patients with chronic periodontitis

The aim of this study was to evaluate the long-term effects of a combined periodontal treatment of scaling and root planing (SRP) and Nd:YAG laser (NDL) in chronic periodontitis (CP) patients. This was accomplished by determining the periodontal indices and the interleukin-1beta (IL-1β) and matrix metalloproteinase-8 (MMP-8) levels of the gingival crevicular fluid (GCF). This study was performed according to a random split-mouth-design, controlled clinical trial for sulcular debridement on 40 teeth from 20 patients with generalized moderate chronic periodontitis. The periodontal healing outcomes were compared after periodontal treatment with either SRP + NDL at 1 W (test side) or SRP (control side). Plaque index (PI), gingival index (GI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded, and samples of gingival crevicular fluid (GCF) were taken at baseline and post-therapy (3 and 9 months after treatment). The GCF samples were analyzed for IL-1β and MMP-8. There was postoperative improvement of all clinical parameters in both groups, but test side GI, PPD, and CAL recovery was higher than that of the control side (p < 0.05). Although levels of IL-1β and MMP-8 in GCF after treatment were lower in the test side than the control side, there was not a statistically significant difference (p > 0.05). In the long term, we found that SRP + NDL treatment of periodontal pockets was more effective than SRP alone in reducing PPD, CAL, GI, and GCF values.

Relationships among gingival crevicular fluid biomarkers, clinical parameters of periodontal disease, and the subgingival microbiota

BACKGROUND

The objectives of this study were to measure levels of gingival crevicular fluid (GCF) biomarkers and subgingival bacterial species in periodontally healthy subjects and subjects with periodontitis to explore the relationships among these biomarkers, the subgingival microbiota, and the clinical parameters of periodontal disease.

METHODS

Clinical periodontal parameters were measured at six sites per tooth in 20 subjects with periodontitis and 20 periodontally healthy subjects. GCF and subgingival plaque samples were obtained from the mesio-buccal aspect of every tooth. GCF levels of interleukin (IL)-1beta and IL-8 and matrix metalloproteinase 8 were measured using checkerboard immunoblotting, and the levels of 40 bacterial taxa were quantified using checkerboard DNA-DNA hybridization. A subset of "clinically healthy" sites from each group was analyzed separately. The significance of the differences between groups was determined using the unpaired t test or the Mann-Whitney test. Correlations among immunologic, microbiologic, and clinical data were determined using the Spearman rank correlation coefficient.

RESULTS

There were positive correlations among mean clinical parameters, mean levels of the three biomarkers, and the proportions of orange and red complex species (P <0.05). Clinically healthy sites from subjects with periodontitis had higher levels of IL-1beta and IL-8 and higher proportions of orange and red complex species (P <0.05) than clinically healthy sites from periodontally healthy subjects. Red complex species were positively associated with the expression of all biomarkers (P <0.05), whereas purple and yellow complex species had negative correlations with IL-1beta and IL-8 (P <0.05).

CONCLUSIONS

Clinically healthy sites from subjects with periodontitis have higher levels of GCF biomarkers and periodontal pathogens than clinically healthy sites from periodontally healthy subjects. Different microbial complexes demonstrated distinct associations with specific GCF biomarkers.

Detection of gingival crevicular fluid MMP-8 levels with different laboratory and chair-side methods

OBJECTIVE

The aim of the study was to compare four methods for gingival crevicular fluid (GCF) matrix metalloproteinase (MMP)-8 detection.

METHODS

Matrix metalloproteinase-8 levels from 20 GCF samples from two periodontally healthy subjects, 18 samples from two patients with gingivitis and 45 samples from six patients with moderate to severe periodontitis, altogether 83 samples, were analysed using (1) a time-resolved immunofluorometric assay (IFMA), (2) an MMP-8 specific chair-side dip-stick test, (3) a dentoAnalyzer device and (4) the Amersham ELISA kit. Western immunoblot using same monoclonal anti-MMP-8 as in IFMA and dentoAnalyzer was used to identify molecular forms of MMP-8 in GCFs.

RESULTS

Correlation between IFMA and dentoAnalyzer results calculated with Spearman's correlation coefficient was 0.95 (P = 0.01). The chair-side dip-stick test results were well in line with these assays. Periodontitis sites with unstable characteristics were differentiated with these methods. The Amersham ELISA results were not in line with the findings by other methods.

CONCLUSIONS

Immunofluorometric assay and dentoAnalyzer can detect MMP-8 from GCF samples and these methods are comparable. Using Western immunoblot, it was confirmed that IFMA and dentoAnalyzer can detect activated 55 kDa MMP-8 species especially in periodontitis-affected GCF. dentoAnalyzer is among the first quantitative MMP-8 chair-side testing devices in periodontal and peri-implant diagnostics and research.

Proteolytic Activities of Oral Bacteria on ProMMP-9 and the Effect of Synthetic Proteinase Inhibitors

Tissue reactions to bacteria lead to proinflammatory reactions involving matrix metalloproteinases (MMPs). Synthetic protease inhibitors may offer new possibilities to regulate bacterial proteases. We investigated proteolytic activities of certain periodontal bacteria, their effects on the latent proMMP-9, and the effects of synthetic MMP inhibitors and a serine protease inhibitor Pefabloc. The strains studied were Porphyromonas gingivalis, Prevotella intermedia, Peptostreptoccus micros, Prevotella nigrescens, Fusobacterium nucleatum, and 5 Aggregatibacter actinomycetemcomitans serotypes. Their gelatinolytic activities and the effects of certain synthetic MMP inhibitors and Pefabloc were analyzed by zymography. Bacterial effects on proMMP-9 conversion were investigated by Western immunoblot. All investigated periodontal bacteria produced gelatinolytic cell-bound and extracellular proteinases which could fragment latent proMMP-9, suggesting co-operative processing cascades in oral tissue remodeling. A. actinomycetemcomitans produced the weakest gelatinolytic activity. Synthetic proteinase inhibitors exhibited slight but clear reductive effects on the bacterial proteolytic activities. We conclude that targeted anti-proteolytic treatment modalities against bacterial-host proteolytic cascades can be developed.