Role of salivary matrix metalloproteinase-8 (MMP-8) in chronic periodontitis diagnosis

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

Objective

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

Data

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

Sources

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

Study selection results

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

Conclusion

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

Clinical significance

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

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.

Association Analysis of MMP-13 (rs2252070) Gene Polymorphism and the Susceptibility to Chronic Periodontitis

BACKGROUND

Chronic periodontitis is a multifactorial inflammatory condition influenced by genetic factors. Matrix metalloproteinase (MMP)-13, serving as a crucial enzyme involved in extracellular matrix remodeling, is associated with the degradation of periodontal tissues. Therefore, this study assesses the genetic link between the MMP-13 (rs2252070) genetic variation and chronic periodontitis in a Southern Indian demographic.

METHODOLOGY

The study was conducted at Saveetha Dental College in Chennai, India. It involved a total of 100 subjects, 50 individuals affected with periodontitis (classified as stage II and above, American Association of Periodontology 2018 criteria) and 50 individuals who were periodontally healthy or were diagnosed as having mild gingivitis. We isolated DNA from the blood samples obtained from the participants. Specific primers that flank the BsrI region of the MMP-13 receptor gene were used in the process of DNA amplification. Subsequently, a restriction fragment length analysis using the BsrI enzyme was carried out for genotyping of the amplicon. Based on the restriction fragment length polymorphism pattern, we obtained certain genotypes. These were further recorded and followed by statistical analysis. We conducted a chi-square test to draw a comparison in terms of their genotype and allele frequencies. We calculated the odds ratio, along with 95% confidence intervals.

RESULTS

The frequency of genotypes and distribution of MMP-13 polymorphism did not exhibit a statistically significant difference at χ2 degrees of freedom (P = 0.913). We inferred from our study that there was no significant difference between the groups concerning homozygous and heterozygous mutant genotypes (AA vs. AG + GG), with a P-value of 0.6871. The observed frequencies of GG (47% vs. 43%) and AG+AA (41% vs. 42%) genotypes did not indicate a significant difference between the groups. Similarly, there was no noteworthy distinction between the A allele (62% vs. 65%) and G allele (38% vs. 35%) in the case and control groups.

CONCLUSION

The findings of the study reveal that there is no correlation between MMP-13 (rs2252070) gene polymorphism and periodontitis.

A disposable immunosensor for the detection of salivary MMP-8 as biomarker of periodontitis

This work describes the development of a novel voltammetric immunosensor for the detection of salivary MMP-8 at the point-of-care. The electrochemical platform was based on a graphene (GPH) screen-printed electrode (SPE) functionalized by gold-nanospheres (AuNSs) and antibodies against MMP-8 protein (anti-MMP-8). The functionalization with anti-MMP-8 was realized by using 11-mercaptoundecanoic acid (11-MUA), thanks to its ability to give strong sulfur bonds with its -SH end, and to cross-link the -NH2 groups of the antibody molecule with the other -COOH end, using the traditional EDC-NHS method. The voltammetric sensor showed good performances with a linear range of 2.5-300 ng mL-1, a LOD value of 1.0 ± 0.1 ng mL-1 and a sensitivity of 0.05 µA mL cm-2 ng-1. Moreover, the proposed immunosensor was tested in real saliva samples, showing comparable results to those obtained with the conventional ELISA method. The biosensor was single-use and cost-effective and required a small quantity of test medium and a short preparation time, representing a very attractive biosensor for MMP-8 detection in human saliva.

Importance of Metalloproteinase 8 (MMP-8) in the Diagnosis of Periodontitis

Periodontitis is a complex condition. Left untreated, it leads to tooth loss and the need for prosthetic treatment. The incidence of periodontitis is steadily increasing, so new methods are being sought to aid in the diagnosis of the disease. Among the methods postulated is the determination of concentrations of bioactive compounds which include extracellular matrix metalloproteinases (MMPs). These enzymes are present in various structural elements of the stomatognathic system. The most promising enzyme of this group appears to be metalloproteinase 8 (MMP-8). MMP-8 assays are performed in gingival fluid or saliva, and MMP-8 levels have been shown to be higher in patients with periodontitis compared to healthy subjects and correlated with some clinical parameters of the condition and the severity of the disease. In addition, the preliminary usefulness of this enzyme in evaluating the effectiveness of periodontal treatment and doxycycline therapy has been demonstrated. Determination of the active form of MMP-8 (aMMP-8) in oral rinse fluid using off-the-shelf assays shows the highest potential. Despite reports about aMMP-8 and promising data on the role of MMP-8 in periodontal diagnosis, a clear determination of the usefulness of this enzyme requires further research.

Feline Chronic Gingivostomatitis Diagnosis and Treatment through Transcriptomic Insights

Feline chronic gingivostomatitis (FCGS) is a debilitating inflammatory oral mucosal disease with a multifactorial etiology. The clinical diagnosis of FCGS is made based on inspection of severe inflammatory lesions and histological confirmation rather than a molecular diagnostic outcome. This gap limits the ability to provide an early diagnosis. In this report, we seek to provide additional diagnostic tools using genomics to aid in providing clinically relevant information. The use of in-depth diagnostic tools, like transcriptomics of diseased tissues, to diagnose FCGS and stratify patients into predictive treatment response groups would dramatically improve both clinical decisions and patient outcomes. In this study, we addressed the gap in diagnostic options using transcriptomic analysis of caudal oral mucosal swab specimens coupled to detailed medical record linkage of FCGS-affected cats undergoing tooth extractions and in some cases administration of mesenchymal stromal cells (MSCs). To better identify markers of disease and potential response to treatment, the transcriptomes of FCGS-afflicted cats were compared to those of healthy cats and those with chronic periodontitis to clearly establish diagnostic biomarker signal transduction connections. Phosphatidylinositol 3-kinase/Ak strain transforming (PI3K/AKT) and stress-activated protein kinases/Jun N-terminal kinase (SAP/JNK) signaling pathways were significantly differentially regulated in FCGS-afflicted cats. Activation of these pathways also differed in the treatment response groups. In conjunction, the enzymes Caspase 4 (CASP4), matrix metalloproteinase-8 (MMP8), and prostaglandin-endoperoxide synthase 2 (PTGS2) were identified as potential biomarkers for the prediction of treatment response outcomes. The observations in the case study support the use of transcriptomics of FCGS patients to contribute to improved molecular diagnostics for the diagnosis and treatment of FCGS.

Exploring the Relation Between Interstitial Lung Diseases and Chronic Periodontitis: A Systematic Review

The objective of this systematic review is to determine the association between interstitial lung diseases and chronic periodontitis from various aspects such as microbial, biomarker, genetic, and environmental levels. A systematic review was carried out from 2000 to 2021 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations including studies searched in PubMed-Medline, Google Scholar, and Cochrane databases. A total of more than 100 articles were obtained in the initial screening process. Out of these 42 studies fulfilled the inclusion criteria and were included in the study. According to the extracted data, there is mounting evidence suggesting the association between these two diseases. Our systematic review raises the prospect of a connection between chronic periodontitis and interstitial lung diseases, within the limitations of the studies we included.

The Role of Doxycycline and IL-17 in Regenerative Potential of Periodontal Ligament Stem Cells: Implications in Periodontitis

Periodontitis (PD) is a degenerative, bacteria-induced chronic disease of periodontium causing bone resorption and teeth loss. It includes a strong reaction of immune cells through the secretion of proinflammatory factors such as Interleukin-17 (IL-17). PD treatment may consider systemic oral antibiotics application, including doxycycline (Dox), exhibiting antibacterial and anti-inflammatory properties along with supportive activity in wound healing, thus affecting alveolar bone metabolism. In the present study, we aimed to determine whether Dox can affect the regenerative potential of periodontal ligament mesenchymal stem cells (PDLSCs) modulated by IL-17 in terms of cell migration, osteogenic potential, bioenergetics and expression of extracellular matrix metalloproteinase 2 (MMP-2). Our findings indicate that Dox reduces the stimulatory effect of IL-17 on migration and MMP-2 expression in PDLSCs. Furthermore, Dox stimulates osteogenic differentiation of PDLSCs, annulling the inhibitory effect of IL-17 on PDLSCs osteogenesis. In addition, analyses of mitochondrial respiration reveal that Dox decreases oxygen consumption rate in PDLSCs exposed to IL-17, suggesting that changes in metabolic performance can be involved in Dox-mediated effects on PDLSCs. The pro-regenerative properties of Dox in inflammatory microenvironment candidates Dox in terms of regenerative therapy of PD-affected periodontium are observed.

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

Objective

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

Methods

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

Results

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

Conclusions

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

Protease-Responsive Hydrogel Microparticles for Intradermal Drug Delivery

Protease-responsive multi-arm polyethylene glycol-based microparticles with biscysteine peptide crosslinkers (CGPGG↓LAGGC) were obtained for intradermal drug delivery through inverse suspension photopolymerization. The average size of the spherical hydrated microparticles was ∼40 μm after crosslinking, making them attractive as a skin depot and suitable for intradermal injections, as they are readily dispensable through 27G needles. The effects of exposure to matrix metalloproteinase 9 (MMP-9) on the microparticles were evaluated by scanning electron microscopy and atomic force microscopy, demonstrating partial network destruction and decrease in elastic moduli. Given the recurring course of many skin diseases, the microparticles were exposed to MMP-9 in a flare-up mimicking fashion (multiple-time exposure), showing a significant increase in release of tofacitinib citrate (TC) from the MMP-responsive microparticles, which was not seen for the non-responsive microparticles (polyethylene glycol dithiol crosslinker). It was found that the degree of multi-arm complexity of the polyethylene glycol building blocks can be utilized to tune not only the release profile of TC but also the elastic moduli of the hydrogel microparticles, with Young's moduli ranging from 14 to 140 kPa going from 4-arm to 8-arm MMP-responsive microparticles. Finally, cytotoxicity studies conducted with skin fibroblasts showed no reduction in metabolic activity after 24 h exposure to the microparticles. Overall, these findings demonstrate that protease-responsive microparticles exhibit the properties of interest for intradermal drug delivery.

The influence of smoking on oral neutrophils and matrix metalloproteinase-8 in periodontitis patients before and after nonsurgical treatment

Objective

To evaluate and compare the oral neutrophil numbers (ONN) in saliva, the level of matrix metalloproteinase-8 (MMP-8) in gingival crevicular fluid (GCF) and the periodontal parameters in smokers versus non-smokers with periodontitis, before and after nonsurgical periodontal treatment (NSPT).

Materials and method

40 chronic periodontitis patients including 20 smokers and 20 non-smokers were enrolled in this quasi-experimental study. All patients were received the NSPT included instructing oral hygiene, scaling and root planing. At baseline (T0) and after NSPT 1 month (T1) and 3 months (T3), all patients were assessed for salivary ONN, GCF MMP-8, and clinical parameters like plaque index (PlI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment loss (CAL). The differences between the two groups were analyzed using the independent sample t-test and the Mann-Whitney U test; and the differences between T0, T1 and T3 of each group were analyzed with paired-samples t-test and Wilcoxon signed-rank test. The level of significance was set at 0.05.

Results

The ONN was significantly less in smokers than in non-smokers although there was no significant difference in other parameters between the two groups at baseline (p > 0.05). All clinical periodontal parameters reduced significantly after 1 month and 3 months of NSPT in both groups (p < 0.01). PPD of non-smokers was significantly lower than those of smokers at T1 and T3. ONN and MMP-8 level showed a significant decrease in non-smoking subjects, while there was no significant difference in smoking ones after NSPT (T1 and T3). At 1 month after treatment, ONN tended to reduce in non-smokers whereas to increase in smokers significantly.

Conclusion

Smoking reduced ONN, impaired treatment effect in reducing PPD, and changed the MMP-8 level in gingival crevicular fluid to NSPT.

Trial registration

Identifier NCT04974502 in CLinicalTrials.gov.

Advances in Electrochemical Biosensors Based on Nanomaterials for Protein Biomarker Detection in Saliva

The focus on precise medicine enhances the need for timely diagnosis and frequent monitoring of chronic diseases. Moreover, the recent pandemic of severe acute respiratory syndrome coronavirus 2 poses a great demand for rapid detection and surveillance of viral infections. The detection of protein biomarkers and antigens in the saliva allows rapid identification of diseases or disease changes in scenarios where and when the test response at the point of care is mandated. While traditional methods of protein testing fail to provide the desired fast results, electrochemical biosensors based on nanomaterials hold perfect characteristics for the detection of biomarkers in point-of-care settings. The recent advances in electrochemical sensors for salivary protein detection are critically reviewed in this work, with emphasis on the role of nanomaterials to boost the biosensor analytical performance and increase the reliability of the test in human saliva samples. Furthermore, this work identifies the critical factors for further modernization of the nanomaterial-based electrochemical sensors, envisaging the development and implementation of next-generation sample-in-answer-out systems.

Relation of salivary MMP-8 with oral submucous fibrosis and oral squamous cell carcinoma: a cross sectional analytical study

OBJECTIVES

We aim to evaluate salivary matrix metalloproteinases (MMP-8) levels in oral submucous fibrosis (OSF) and oral squamous cell carcinoma (OSCC) for the purpose of diagnosis at the early stage via non-invasive method.

SETTING

The study was multicentre, carried out at a tertiary care hospital in Karachi, Pakistan.

PARTICIPANTS

A total 60 participants of any age, sex and ethnicity were randomly selected for the purpose of this study. Patients demonstrating clinical evidence of OSF and biopsy-proven cases of OSCC were included. Patients with indeterminate histopathological report, immunodeficiency, autoimmune disorder, chronic medical and periodontal disease (periodontal depth greater than 5 mm) and individuals with interincisal mouth opening greater than 35 mm were excluded from the study.

INTERVENTIONS

Salivary MMP-8 levels were observed in OSF, healthy and OSCC groups by using ELISA. One way analysis of variance was applied to establish whether MMP-8 levels of disease-free individuals and patients suffering from OSF and OSCC differed from each other.

RESULTS

Statistically significant difference in salivary MMP-8 expression in diseased and control group was observed. MMP-8 levels in OSCC (0.64 ng/mL) and OSF (0.66 ng/mL) were underexpressed as compared with healthy participants (7.9 ng/mL).

CONCLUSION

MMP-8 levels were underexpressed in OSCC and OSF patients as compared with controls, which imply that MMP-8 level has an inverse relation with OSCC and OSF.

Matrix Metalloproteinases in Dental and Periodontal Tissues and Their Current Inhibitors: Developmental, Degradational and Pathological Aspects

Objectives: This review article aims to describe some of the roles of Matrix metalloproteinases (MMPs) in enamel, dentine, dental caries, hybrid layer degradation, pulp and periodontal tissues, throwing light on their current inhibitors. The article addresses the potential of MMPs to serve as biomarkers with diagnostic and therapeutic value. Design: The sections of this review discuss MMPs’ involvement in developmental, remodeling, degradational and turnover aspects of dental and periodontal tissues as well as their signals in the pathogenesis, progress of different lesions and wound healing of these tissues. The literature was searched for original research articles, review articles and theses. The literature search was conducted in PubMed and MEDLINE for articles published in the last 20 years. Results: 119 published papers, two textbooks and two doctoral theses were selected for preparing the current review. Conclusions: MMPs are significant proteases, of evident contribution in dental and periapical tissue development, health and disease processes, with promising potential for use as diagnostic and prognostic disease biomarkers. Continuing understanding of their role in pathogenesis and progress of different dental, periapical and periodontal lesions, as well as in dentine-pulp wound healing could be a keystone to future diagnostic and therapeutic regimens.

Assessing salivary matrix metalloproteinase‐8 in prostate cancer patients undergoing androgen deprivation therapy

Introduction

Matrix metalloproteinase‐8 (MMP‐8) is considered as one of the most promising diagnostic markers for periodontal disease. Androgen deprivation therapy (ADT) has been correlated with impaired collagen synthesis and an increase in periodontal tissue susceptibility to pathogenic microorganisms.

Objective

This study aims to investigate the impact of ADT on salivary MMP‐8 level and periodontal parameters, which might be useful in monitoring periodontal disease in prostate cancer patients undergoing ADT.

Materials and Methods

A total of 88 subjects were selected and were divided into two groups: Group I included n = 78 PC patients who have been undergoing ADT); Group II included n = 10 healthy individuals. Periodontal parameters such as plaque index (PI), gingival index (GI), periodontal probing depth (PPD), and clinical attachment level (CAL) were examined. The salivary MMP‐8 level was estimated by using the sandwich enzyme‐linked immunosorbent assay method.

Results

Significant differences in mean salivary MMP‐8 level were found between PC patients undergoing ADT and healthy individuals. Salivary MMP‐8 levels of all individuals were positively correlated with GI, PI, PPD, and CAL. Salivary MMP‐8 can distinguish between periodontitis and healthy individuals with an accuracy of about 80%.

Conclusion

Salivary MMP‐8 levels were found to be higher in prostate cancer patients undergoing ADT compared to healthy individuals.

The utility of gingival crevicular fluid matrix metalloproteinase-8 provides site-specific diagnostic value for periodontal grading

INTRODUCTION

Matrix metalloproteinase-8 (MMP-8), and its active form aMMP-8, was identified as a potential biomarker of periodontal tissue destruction. It is present at different concentrations in various oral fluids.

MATERIAL AND METHODS

Gingival crevicular fluid (GCF) samples were collected from periodontal pockets ≥ 6 mm of 24 untreated patients using paper points and clinical parameters were recorded. 12 subjects were diagnosed with periodontitis stage III grade B, and 12 others with periodontitis stage III grade C. After thorough preparations, samples were collected following manufacturers' instructions and analyzed using a commercially available test system for aMMP-8 evaluation (aMMP-8 Test) and Periotron 8000 together with Quantikine kits for assessment of total MMP-8 concentration (controls). Microbiological evaluation of the same pockets was carried out using real-time polymerase chain reaction.

RESULTS

Concentrations of both total MMP-8 and aMMP-8 in GCF were higher in the case of periodontitis grade C, compared to periodontitis grade B, but reached statistical significance only in the case of total MMP-8 (77.17 ng/ml and 18.73 ng/ml respectively; p = 0.0104). Positive correlations were found between total MMP-8 and aMMP-8 levels and the prevalence of Fusobacterium nucleatum, mean probing pocket depth of all pockets, % of pockets ≥ 6 mm, as well as probing pocket depth of pocket from which GCF samples were collected.

CONCLUSIONS

GCF concentration levels of both total MMP-8 and aMMP-8 correlated with severity of periodontal destruction, whereas total MMP-8 appeared to be a preferable method for differentiation of periodontal grading. However, the aMMP-8 Test was easier and more convenient to handle.

Diagnostic Models for Screening of Periodontitis with Inflammatory Mediators and Microbial Profiles in Saliva

This study aims to investigate and assess salivary biomarkers and microbial profiles as a means of diagnosing periodontitis. A total of 121 subjects were included: 28 periodontally healthy subjects, 24 with Stage I periodontitis, 24 with Stage II, 23 with Stage III, and 22 with Stage IV. Salivary proteins (including active matrix metalloproteinase-8 (MMP-8), pro-MMP-8, total MMP-8, C-reactive protein, secretory immunoglobulin A) and planktonic bacteria (including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Porphyromonas nigrescens, Parvimonas micra, Campylobacter rectus, Eubacterium nodatum, Eikenella corrodens, Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Actinomyces viscosus) were measured from salivary samples. The performance of the diagnostic models was assessed by receiver operating characteristics (ROCs) and area under the ROC curve (AUC) analysis. The diagnostic models were constructed based on the subjects’ proteins and/or microbial profiles, resulting in two potential diagnosis models that achieved better diagnostic powers, with an AUC value > 0.750 for the diagnosis of Stages II, III, and IV periodontitis (Model PA-I; AUC: 0.796, sensitivity: 0.754, specificity: 0.712) and for the diagnosis of Stages III and IV periodontitis (Model PA-II; AUC: 0.796, sensitivity: 0.756, specificity: 0.868). This study can contribute to screening for periodontitis based on salivary biomarkers.

Oral Fluid Biomarkers for Diagnosing Gingivitis in Human: A Cross-Sectional Study

Diagnoses based on oral fluid biomarkers have been introduced to overcome limitations of periodontal probe-based diagnoses. Diagnostic ability of certain biomarkers for periodontitis have been identified and widely studied, however, such studies targeting gingivitis is scarce. The aims of this study were to determine and compare the efficacies and accuracies of eight biomarkers in diagnosing gingivitis with the aid of receiver operating characteristic (ROC) curves. The probing depth (PD), clinical attachment loss (CAL), bleeding on probing (BOP), gingival index (GI), and plaque index (PI) were examined in 100 participants. Gingival crevicular fluid was collected using paper points, and whole-saliva samples were collected using cotton roll. Samples were analyzed using enzyme-linked immunosorbent assay kits for the different biomarkers. The levels of matrix metalloproteinase (MMP)-8, MMP-9, lactoferrin, cystatin C, myeloperoxidase (MPO), platelet-activating factor, cathepsin B, and pyridinoline cross-linked carboxyterminal telopeptide of type I collagen were analyzed. MPO and MMP-8 levels in saliva were strongly correlated with gingivitis, with Pearson’s correlation coefficients of 0.399 and 0.217, respectively. The area under the curve (AUC) was largest for MMP-8, at 0.814, followed by values of 0.793 and 0.777 for MPO and MMP-9, respectively. The clinical parameters of GI and PI showed strong correlations and large AUC values, whereas PD and CAL did not. MMP-8 and MPO were found to be effective for diagnosing gingivitis. Further investigations based on the results of this study may identify clinically useful biomarkers for the accurate and early detection of gingivitis.

Expression of β-catenin and MMP-8 in gingival crevicular fluid and gingival tissue indicates the disease severity of patients with chronic periodontitis

The aim of the present study was to investigate the interaction among β-catenin, matrix metalloproteinase-8 (MMP-8) and severity in patients with chronic periodontitis. Both gingival crevicular fluid (GCF) and gingival tissue was collected from 21 healthy control individuals, 21 patients with moderate chronic periodontitis (mCP) and 23 patients with severe chronic periodontitis (sCP). The concentration of MMP-8 in GCF was detected via ELISA and the mRNA levels of β-catenin and MMP-8 in GCF and gingival tissue was detected via reverse transcription-quantitative PCR. The protein levels of β-catenin and MMP-8 in gingival tissue was detected using western blotting and the interaction between β-catenin and MMP-8 in gingival tissue was detected by co-immunoprecipitation. The expression of β-catenin and MMP-8 was significantly higher in the GCF and gingival tissue of patients with chronic periodontitis (mCP and sCP) compared with the control patients. Furthermore, the expression of β-catenin and MMP-8 in GCF and gingival tissue was positively correlated with the clinical attachment level. In addition, a positive interaction was identified between β-catenin and MMP-8, and the expression of β-catenin was positively correlated with the expression of MMP-8 in GCF and gingival tissue. The CGF and gingival tissue expression of β-catenin and MMP-8 may indicate disease severity in patients with chronic periodontitis.

MMP-8-Responsive Polyethylene Glycol Hydrogel for Intraoral Drug Delivery

Currently available drug delivery systems for oral diseases suffer from short retention time and poor local concentrations at the target site. A biodegradable stimulus-responsive hydrogel was synthesized in the present study to evaluate its application as an environmentally sensitive carrier for on-demand intraoral drug delivery. The hydrogel was synthesized from diacrylate-containing polyethylene glycol-based scaffolds and a cysteine-terminated peptide crosslinker (CGPQG↓IWGQC) via a Michael-type addition reaction. Because CGPQG↓IWGQC can be cleaved by matrix metalloproteinase 8 (MMP-8), minocycline hydrochloride, bovine serum albumin, or an antibacterial peptide (KSL) was incorporated into the scaffolds to evaluate the MMP-8-responsive release behavior of the on-demand drug delivery system. Hydrogel characterization and gelation kinetics were examined with gel time, Fourier-transform infrared spectroscopy, scanning electron microscopy, and measurements of rheologic parameters. Degradation behavior and MMP-8-responsive drug release were performed by high-performance liquid chromatography and protein-specific assay. Biocompatibility evaluation indicated that the hydrogels were noncytotoxic. Antibacterial testing demonstrated that the released drugs were able to maintain bioactivity. Taken together, these results suggest that the MMP-8-sensitive hydrogel is a promising candidate for on-demand intraoral localized drug delivery. Because MMP-8 is one of the most important biomarkers for periodontitis, the MMP-8-responsive hydrogel has potential to be used for in situ adaptive degradation in response to chronic periodontitis and peri-implantitis. This notion has to be tested in animal models of periodontal disease.

Clinical evaluation of non-surgical cleaning modalities on titanium dental implants during maintenance care: a 1-year follow-up on prosthodontic superstructures

OBJECTIVES

To investigate tissue health around implants with newly attached superstructures over 12 months of preventive maintenance appointments and instrumentation when necessary.

MATERIAL AND METHODS

In a randomized, split-mouth study 32 implants (8 participants with 4 implants each) received followed-up care every 3 months after superstructure attachment. Implants and superstructures were randomly assigned to four treatment groups and treated if necessary: (1) titanium curettes (TC), (2) stainless steel ultrasonic tip (PS), (3) erythritol air-polishing powder (EP), or (4) rubber cup polishing (CON). Probing depths (PDs), bleeding on probing (BOP), modified gingival (mucosal) bleeding index (GBI) around implants, and full-mouth Plaque Control Record (PCR) were measured every 3 months. Clinical attachment levels (CALs) and height of keratinized mucosa (KM)/gingival margins (GMs) for implants/teeth and PD, BOP, and GBI for teeth were documented at baseline, 6 months, and 12 months. Matrix metalloproteinase 8 (MMP-8) and periopathogens were measured at baseline and 12 months.

RESULTS

Participants exhibited minimal signs of periodontal inflammation with statistically significant PD improvement (3.0 ± 0.2 to 2.8 ± 0.3 mm; p = 0.022) and overall CAL (4.3 ± 0.8 to 4.0 ± 0.7 mm; p = 0.048) after 1 year. Implants showed no statistically significant differences (p > 0.05) between or within groups at baseline or 12 months for any parameter, except MMP-8 decreased significantly for PS (14.50 ± 17.58 to 4.63 ± 7.56 ng; p = 0.044), and after 12 months, PCR showed a significant difference between TC and PS (p = 0.018).

CONCLUSIONS

Treatment was necessary as inflammation was observed around newly placed superstructures within the first year of maintenance care. All tested treatment modalities yielded comparable clinical improvements.

CLINICAL RELEVANCE

Early assessment and diagnosis of mucositis and regular maintenance can promote long-lasting implant health.

Matrix metalloproteinase-8 levels in oral samples as a biomarker for periodontitis in the Chinese population: an observational study

BACKGROUND

Clinical evaluation of periodontal inflammation does not fully reflect the disease activity. Extensive studies have been conducted out on gingival crevicular fluid (GCF) components that might serve as potential diagnostic markers for periodontitis, among which matrix metalloproteinase-8 (MMP-8) has shown to be promising, but there were no studies for individuals in China. The aim of this study was to compare clinical diagnostic parameters and levels of active MMP-8 (aMMP-8) in GCF and oral rinse samples from the Chinese patients with varying degrees of periodontal inflammation.

METHODS

GCF and oral rinse samples were obtained from 60 participants into two groups, a periodontitis group and a control group, specified by the presence and number of pocket depths or attachment loss. The aMMP-8 levels in GCF and oral rinse samples was quantified by ELISA using specific monoclonal antibodies. Logistic and linear regression models were employed for testing the correlation between aMMP-8 levels and periodontal condition, as well as diagnostic sensitivity and specificity.

RESULTS

Periodontitis group (mean = 24.84 ng/ml) exhibited significantly higher aMMP-8 levels than control group in GCF (p < 0.001). The aMMP-8 levels in oral rinse samples ranged from 0.05 to 2.18 ng/ml, but differences were not statistically significant between the two groups (p > 0.1). Receiver operating characteristic curve analysis showed a highest threshold of 6.66, with a corresponding sensitivity and specificity of 0.8 and 0.9, respectively.

CONCLUSIONS

Measuring aMMP-8 levels in GCF may have potentiality for complementary early diagnosis of periodontal disease and inflammation in the Chinese population.

Salivary matrix metalloproteinase (MMP)-8 as a biomarker for periodontitis: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Salivary matrix metalloproteinase (MMP)-8 is currently considered to be one of the most promising biomarkers for early diagnosis of periodontitis, however, several recent studies showed conflicting results.

OBJECTIVE

To determine the salivary matrix metalloproteinase (MMP)-8 levels between periodontitis patients and healthy individuals, and to assess its diagnostic value in periodontitis.

METHODS

Literatures were searched on PubMed and Embase databases up to August 2017, for articles reporting salivary MMP-8 levels between periodontitis patients and health controls with the data of means ± standard deviation (SD). Methodological quality was assessed by the Newcastle Ottawa scale (NOS). Standard mean differences (SMDs), heterogeneity, and publication bias were assessed by Stata 13.0 software.

RESULTS

A total of 10 studies including 485 periodontitis patients and 379 healthy controls that met the preset inclusion criteria were included, the qualities of these studies were either good (n = 7) or moderate (n = 3). Eight studies showed salivary MMP-8 levels were higher in periodontitis patients compared with healthy controls (P < .05), while 2 studies showed opposite results (P > .05). The pooled SMD was 1.195 (95% CI: 0.720-1.670), with I of 89.3%, indicating high heterogeneity. Funnel plot showed publication bias existed.

CONCLUSION

Our meta-analysis showed that salivary MMP-8 levels were significantly higher in periodontitis patients compared with healthy controls overall. Due to the heterogeneity and publication bias of included studies, further high quality studies are still needed to verify the conclusion.

Clinical and laboratory evaluation of the effects of different treatment modalities on titanium healing caps: a randomized, controlled clinical trial

OBJECTIVES

The objective of this study is to evaluate the effects of treatment modalities on titanium surface characteristics and surrounding tissues.

MATERIALS AND METHODS

Eighteen participants each had four titanium healing caps (HC) attached to four newly inserted implants. After healing, each HC was randomly assigned to either (1) titanium curettes (TC), (2) stainless steel ultrasonic tip (PS), (3) erythritol air-polishing powder (EP), or (4) only rubber cup polishing (CON). Probing depths (PD), bleeding on probing (BOP), matrix metalloproteinase 8 (MMP-8), and periopathogens were recorded before and 3 months following instrumentation. After final assessments, HCs were removed, cleaned, and subjected to (a) bacterial colonization (Streptococcus gordonii, 24 h; mixed culture, 24 h) and (b) gingival fibroblasts (5 days). HC surfaces were analyzed with a scanning electron microscope (SEM).

RESULTS

No significant differences between the groups were evident before or after instrumentation for PD and BOP (except TC showed a significant decrease in PD; p = 0.049). MMP-8 levels and bacterial loads were always very low. MMP-8 decreased further after instrumentation, while bacteria levels showed no change. No significant differences (p > 0.05) were evident in bacterial colonization or fibroblast attachment. A comparison of the overall mean SEM surface roughness scores showed a significant difference between all groups (p < 0.0001) with the lowest roughness after EP.

CONCLUSIONS

All treatments performed yielded comparable outcomes and may be implemented safely.

CLINICAL RELEVANCE

Clinicians may fear implant surface damage, but all instrumentation types are safe and non-damaging. They can be implemented as needed upon considering the presence of staining and soft and hard deposits.

Ligature-induced peri-implantitis and periodontitis in mice

AIM

Peri-implantitis (PI), inflammation around dental implants, shares characteristics with periodontitis (PD). However, PI is more difficult to control and treat, and detailed pathophysiology is unclear. We aimed to compare PI and PD progression utilizing a murine model.

MATERIALS AND METHODS

Four-week-old male C57BL/6J mice had their left maxillary molars extracted. Implants were placed in healed extraction sockets and osseointegrated. Ligatures were tied around the implants and second molars. Controls did not receive ligatures. Mice were sacrificed 1 week, 1 and 3 months (n ≥ 5/group/time point) post-ligature placement. Bone loss analysis was performed. Histology was performed for: haematoxylin and eosin (H&E), tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinase-8 (MMP-8), nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB), toluidine blue and calcein.

RESULTS

PI showed statistically greater bone loss compared to PD at 1 and 3 months. At 3 months, 20% of implants in PI exfoliated; no natural teeth exfoliated in PD. H&E revealed that alveolar bone surrounding implants in PI appeared less dense compared to PD. PI presented with increased osteoclasts, MMP-8 and NF-κB, compared to PD.

CONCLUSION

PI exhibited greater tissue and bone destruction compared to PD. Future studies will characterize the pathophysiological differences between the two conditions.

Matrix metalloproteinase-8 levels in periodontal disease patients: A systematic review

Periodontal disease is characterized as a disorder of the oral microbiota resulting in an immune response which, in turn, leads to the destruction of periodontal tissue. Matrix metalloproteinase-8 (MMP-8) has been reported as the major metalloproteinase involved in periodontal disease, being present at high levels in gingival crevicular fluid and salivary fluid (SF). The aim of this systematic review was to evaluate the scientific literature regarding the expression of MMP-8 in gingival crevicular fluid and SF in patients with periodontal disease, analyzing its validity as a possible biomarker in the diagnosis of periodontal disease. A systematic review of the literature was performed using the PubMed/Medline, CENTRAL and Science Direct databases. Studies concerning the use of MMP-8 in the diagnosis of periodontal disease that evaluated its effectiveness as a biomarker for periodontal disease were selected. The search strategy provided a total of 6483 studies. After selection, six articles met all the inclusion criteria and were included in the present systematic review. The studies demonstrated significantly higher concentrations of MMP-8 in patients with periodontal disease compared with controls, as well as in patients presenting more advanced stages of periodontal disease. The findings on higher MMP-8 concentrations in patients with periodontal disease compared with controls imply the potential adjunctive use of MMP-8 in the diagnosis of periodontal disease.

The emerging roles of B cells as partners and targets in periodontitis

Initial studies of periodontal disease suggested that T cell-mediated immunity against oral Gram-negative microorganisms is a key player in the pathogenesis of this inflammatory disease. Recent investigations, however, revealed that B cells are also engaged. Given their chief role in innate-like and adaptive immune responses, B cells could exert protective functions in periodontitis. However, the periodontal bacteria-specific antibody response is generally unable to halt disease progression in affected subjects, suggesting that the antibodies produced could exhibit low anti-bacterial blocking functions or opsonophagocytic potential, and/or unfavorable effects. Moreover, although microbial antigens are involved in the induction of the inflammatory responses in human adult periodontitis, endogenous antigens also may contribute to the chronicity of this common disease. Not only antibodies to self-antigens, such as collagen, are locally produced, but the autoreactivities observed in aggressive periodontitis are more severe and diverse than those observed in chronic periodontitis, suggesting that autoimmune reactivity could play a role in the tissue destruction of periodontal disease. Further support for a pathological role of B cells in periodontitis comes from the finding that B cell-deficient mice are protected from bacterial infection-induced alveolar bone loss. Studies in patients indicate that B cells and plasma cells, together with osteoclastogenic factors (RANKL and osteoprotegerin) and specific cytokines involved in their growth and differentiation (BAFF and APRIL) participate in the induction of the pathological bone loss in periodontitis. This novel insight suggests that selective targeting of B cells could represent a future therapeutic avenue for severe periodontal disease.

Rapid assessment of salivary MMP-8 and periodontal disease using lateral flow immunoassay

OBJECTIVE

The objective of this study was to determine the efficacy of a novel point-of-care immunoflow device (POCID) for detecting matrix metalloproteinase (MMP)-8 concentrations in oral fluids in comparison with a gold standard laboratory-based immunoassay.

METHODS

Oral rinse fluid and whole expectorated saliva samples were collected from 41 participants clinically classified as periodontally healthy or diseased. Samples were analyzed for MMP-8 by Luminex immunoassay and POCID. Photographed POCID results were assessed by optical scan and visually by two examiners. Data were analyzed by Pearson's correlation and receiver-operating characteristics.

RESULTS

MMP-8 was readily detected by the POCID, and concentrations correlated well with Luminex for both saliva and rinse fluids (r = 0.57-0.93). Thresholds that distinguished periodontitis from health were delineated from both the optical scans and visual reads of the POCID (sensitivity: 0.7-0.9, specificity: 0.5-0.7; P < 0.05).

CONCLUSIONS

Performance of this POCID for detecting MMP-8 in oral rinse fluid or saliva was excellent. These findings help demonstrate the utility of salivary biomarkers for distinguishing periodontal disease from health using a rapid point-of-care approach.

Association of synovial inflammation and inflammatory mediators with glenohumeral rotator cuff pathology

HYPOTHESIS

We hypothesized that patients with full-thickness rotator cuff tears would have greater synovial inflammation compared with those without rotator cuff tear pathology, with gene expression relating to histologic findings.

METHODS

Synovial sampling was performed in 19 patients with full-thickness rotator cuff tears (RTC group) and in 11 patients without rotator cuff pathology (control group). Cryosections were stained and examined under light microscopy and confocal fluorescent microscopy for anti-cluster CD45 (common leukocyte antigen), anti-CD31 (endothelial), and anti-CD68 (macrophage) cell surface markers. A grading system was used to quantitate synovitis under light microscopy, and digital image analysis was used to quantify the immunofluorescence staining area. Quantitative polymerase chain reaction was performed for validated inflammatory markers. Data were analyzed with analysis of covariance, Mann-Whitney U, and Spearman rank order testing, with significance set at α = .05.

RESULTS

The synovitis score was significantly increased in the RTC group compared with controls. Immunofluorescence demonstrated significantly increased staining for CD31, CD45, and CD68 in the RTC vs control group. CD45+/68- cells were found perivascularly, with CD45+/68+ cells toward the joint lining edge of the synovium. Levels of matrix metalloproteinase-3 (MMP-3) and interleukin-6 were significantly increased in the RTC group, with a positive correlation between the synovitis score and MMP-3 expression.

CONCLUSIONS

Patients with full-thickness rotator cuff tears have greater levels of synovial inflammation, angiogenesis, and MMP-3 upregulation compared with controls. Gene expression of MMP-3 correlates with the degree of synovitis.

Clinical Therapeutic Effects of the Application of Doxycycline in the Treatment of Periodontal Disease

OBJECTIVE

To compare the therapeutic effects of the application of doxycycline-full dose (100 mg) and sub-dose (20 mg) in the treatment of periodontal disease.

MATERIAL AND METHODS

A total of 60 patients with periodontal disease were examined. Patients are divided into two groups: A) treated with antimicrobial dose of 100 mg doxycycline once daily for 30 days, and B) treated with 2 x 20 mg/day. doxycycline, during 75 days. Among all patients a conservative treatment was carried out and ordinated the proper dose doxycycline in total dose during treatment from 3 gr. Index of dental plaque by Löe-Sillness, index of gingival inflammation and gingival bleeding by Cowell were followed.

RESULTS

Values of dental plaque in relation first examination, 10th, 20th day, 1 month and 2.5 months, showed that after 2.5 months, average value (x = 0.83) of dental plaque in second group is slightly less than the value (x = 0.93) of dental plaque in the first group. The average value (x = 0.17) of gingival inflammation in second group is significantly less than the value (x = 0.50) of gingival inflammation in the first group. The average value (x = 0.97) of gingival bleeding in patients from the first group was significantly higher than value(x = 0.37) of gingival bleeding in the second group.

CONCLUSION

Patients whose therapy was helped by a sub-dose doxycycline demonstrated positive therapeutic effects on gingival inflammation and bleeding.

Influence of mechanical compression on human periodontal ligament fibroblasts and osteoblasts

OBJECTIVES

The aim of this study was to investigate and compare the changes in human periodontal ligament fibroblasts (HPdLFs) and osteoblasts (HOBs) after the application of compressive force (CF) at two different strengths in vitro.

MATERIALS AND METHODS

HPdLF and HOB were exposed to CF with various strengths (5 and 10 %) using a Flexercell Compression Unit for 12 h in vitro. Viability was detected via 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) and apoptosis rate by transferase dUTP nick end labeling (TUNEL) assay. The gene expression of alkaline phosphatase (ALP), osteocalcin (OCN), osteoprotegerin (OPG), and receptor activator of NF-κB ligand (RANKL) was analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Osteopontin (OPN), matrix metalloproteinase-8 (MMP-8), and tissue inhibition of metalloproteinase-1 (TIMP-1) were quantified by an ELISA.

RESULTS

Ten percent CF decreased viability, particularly in HOBs, but did not induce increased apoptosis. ALP gene expression increased the most after 5 % CF in HPdLFs and after 10 % CF in HOB. OCN was not affected by CF in either cell line. The highest RANKL/OPG ratio was measured after 5 % CF in both cell lines. OPN was upregulated in HOB by 5 %. HPdLFs showed an upregulation of MMP-8-synthesis and an increased MMP-8/TIMP-1 ratio.

CONCLUSIONS

HOBs have a greater effect on bone remodeling through the upregulation of OPN, whereas HPdLFs facilitate orthodontic tooth movement by influencing the extracellular matrix via the MMP-8/TIMP-1 ratio.

CLINICAL RELEVANCE

High CF in orthodontics should be avoided to prevent tissue damage, whereas moderate CF enables active tissue remodeling and tooth movement.