Matrix metalloproteinases and myeloperoxidase in gingival crevicular fluid provide site-specific diagnostic value for chronic periodontitis

Diagnostic value of aMMP-8 and azurocidin in peri-implant sulcular fluid as biomarkers of peri-implant health or disease

OBJECTIVE

The objective of this study was to investigate the effectiveness of testing for active matrix metalloproteinase-8 (aMMP-8) by a quantitative point-of-care (PoC), chairside lateral flow immunotest and azurocidin, in the peri-implant sulcular fluid (PISF), as biomarkers for the presence or absence of peri-implant diseases.

BACKGROUND

Current research indicates that proinflammatory cytokines and extracellular matrix-degrading enzymes may be of value to diagnose and predict peri-implant disease initiation and progression, but more data are needed.

METHODS

Eighty patients with implants were recruited. PISF samples were collected and quantitatively analyzed for aMMP-8 (chairside) and azurocidin with ELISA. Radiographic assessments and clinical indices (probing depth, probing attachment level, bleeding on probing, and plaque) were recorded after sampling. Kruskal-Wallis test and pairwise post hoc Dunn-Bonferroni test were used to relate aMMP-8 levels and azurocidin levels to clinical parameters. The diagnostic ability of aMMP-8 (ng/mL) and azurocidin was analyzed by receiver operator curve analysis. Area under the curve (AUC) was calculated and the Spearman's rho, and the coefficient of determination (R2) were used to calculate the correlations between aMMP-8, azurocidin, and periodontal parameters.

RESULTS

Statistically significant differences were observed for aMMP-8 levels but not for azurocidin between healthy implants, implants with mucositis, and those with peri-implantitis (13.65 ± 7.18, 32.33 ± 21.20, and 73.07 ± 43.93 ng/mL, respectively), (Kruskall-Wallis test p < .05). The aMMP-8 test with a threshold of 20 ng/mL has a sensitivity of 71.7% and a specificity of 77.8% to identify peri-implantitis and healthy implants, respectively. AUC was found to be 0.814, and the accuracy of the method reaches 73.8%. Above a cutoff value of 33.7 ng/mL of aMMP-8, the accuracy of the test to detect peri-implantitis reaches 77.5% in relation to 62.5% of BoP from the same site.

CONCLUSION

Taken collectively, present data indicate that the aMMP-8 PoC lateral flow immunotest can be a beneficial, adjunctive diagnostic quantitative tool for real-time screening for peri-implant diseases.

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.

Salivary levels of azurocidin and soluble azurophilic granules in periodontal disease

Periodontitis is an infection-driven inflammatory condition of the periodontium. Neutrophils are one of the most important first-line immune cells that protect against pathogen microorganisms in the saliva, but they may also mediate tissue death in inflammatory disorders. The aim of our study was to estimate salivary levels of azurocidin and extracellular azurophilic granules cluster of differentiation (CD63) as biomarkers of neutrophil activation in patients with periodontal diseases and to study the correlation between the levels of these two biomarkers and clinical periodontal parameters. The study included 60 patients with periodontal disease (30 patients with periodontitis and 30 with gingivitis) and 25 healthy controls. The assessed parameters were bleeding on probing, the plaque index, clinical attachment loss, and probing pocket depth. Saliva samples were taken from each study participant, and azurocidin and CD63 levels were measured using ELISA. Azurocidin and CD63 levels were significantly higher in patients with periodontitis and patients with gingivitis than in controls (P < 0.05), and significantly higher in patients with periodontitis than in patients with gingivitis (P < 0.05). Moreover, we found a significant positive correlation between the two biomarkers with clinical attachment loss in the periodontitis group. This study has shown that increased salivary azurocidin and extracellular CD63 levels are associated with enhanced innate response in periodontal disease and can be considered biomarkers of neutrophil activation.

Correlations between different protein species of oral rinse MMP-8 and patient-related factors

OBJECTIVES

The aim of this study is to examine correlations between different oral rinse matrix metalloproteinase (MMP)-8 protein species in western blot (WB) analysis, quantitative MMP-8 measurements, and patient-related factors. Elevated activated MMP-8 (aMMP-8) associate with periodontitis and a diagnostic point-of-care technology has been developed based on aMMP-8. In WB, different MMP-8 protein species can be analyzed. Relative abundancy of fragmented 20-25 kDa forms in WB has been associated with and reflects MMP-8 activation and related fragmentation and elevated quantitative aMMP-8 measurements.

MATERIAL AND METHODS

A random sample of 192 participants from a periodontal disease screening study was used for this study. Oral rinse samples for biomarker analyses were collected before clinical periodontal examinations. aMMP-8 immunofluorometric (IFMA) and WB analysis (utilizing the same monoclonal antibody, 8708), polymorphonuclear leukocyte (PMN) elastase activity test and tissue inhibitor of metalloproteinases (TIMP)-1 ELISA levels were performed from the oral rinse samples. Distinct MMP-8 protein species were differentiated in the WB analysis. Principal component (PC) analysis was conducted to explore correlation patterns between the different species. Adjusted correlation analysis between the extracted PCs of WB and aMMP-8 IFMA levels and multilevel regression analysis were conducted to explore if the other periodontal disease-related biomarkers and clinical surrogate measures and patient-related factors are co-variating with the extracted components.

RESULTS

Distinct correlation patterns between the MMP-8 protein species were observed. The first four PCs explained 89% of the whole variance in PC analysis. Statistically significant correlation (p < 0.05) were observed as follows: PC1 positively with 21 kDa (r = .69) and 25 kDa fragments (r = .55) and negatively with 150 kDa complexes (r = -.46). PC2 correlated with 45 (r = .70) and 55 kDa (r = .65) activated forms, PC3 with 70-80 kDa latent proforms (r = .63) and 90-100 kDa complexes (r = .67), and PC4 with 35 kDa fragments (r = .81). There were significant correlations between quantitative (IFMA) aMMP-8 measurements and PC1 (p < 0.001), PC2 (<0.05) and PC3 (<0.05) but not with PC4. In multilevel regression models age, PMN elastase activity, TIMP-1 levels, and a number of 4-5 mm periodontal pockets were associated with PC1, nonsmoking with PC2, age and PMN elastase activity with PC3, and age and smoking with PC4.

CONCLUSIONS

Relative abundancy of fragmented 21-25 kDa protein species was correlated with the quantitative aMMP-8 (IFMA) measurements, which is in line with previous results. Different patient-related factors (smoking, age, proteolytic activity) may modify the formation of different MMP-8 protein species in oral rinse samples and may cause variability in quantitative aMMP-8 measurement.

The tree shrew as a new animal model for the study of periodontitis

AIM

Periodontitis is an inflammatory, infectious disease of polymicrobial origin that can damage tooth-supporting bone and tissue. Tree shrews, evolutionarily closer to humans than commonly used rodent models, have been increasingly used as biomedical models. However, a tree shrew periodontitis model has not yet been established.

MATERIALS AND METHODS

Periodontitis was induced in male tree shrews/Sprague-Dawley rats by nylon thread ligature placement around the lower first molars. Thereafter, morphometric and histological analyses were performed. The distance from the cemento-enamel junction to the alveolar bone crest was measured using micro-computed tomography. Periodontal pathological tissue damage, inflammation and osteoclastogenesis were assessed using haematoxylin and eosin staining and quantitative immunohistochemistry, respectively.

RESULTS

Post-operatively, gingival swelling, redness and spontaneous bleeding were observed in tree shrews but not in rats. After peaking, bone resorption decreased gradually until plateauing in tree shrews. Contrastingly, rapid and near-complete bone loss was observed in rats. Inflammatory infiltrates were observed 1 week post operation in both models. However, only the tree shrew model transitioned from acute to chronic inflammation.

CONCLUSIONS

Our study revealed that a ligature-induced tree shrew model of periodontitis partly reproduced the pathological features of human periodontitis and provided theoretical support for using tree shrews as a potential model for human periodontitis.

Active MMP-8 as a Biomarker of Peri-implant Health or Disease

OBJECTIVES

 This study investigated the potential of testing for active matrix metalloproteinase-8 (aMMP-8) by a quantitative point-of-care (PoC), chairside, lateral flow immunotest as a biomarker for the presence or absence of peri-implant diseases.

MATERIALS AND METHODS

 Eighty healthy patients with implants were recruited. The samples were collected from peri-implant sulcular fluid and quantitatively analyzed for aMMP-8. Clinical indices, which included probing depth, clinical attachment loss, bleeding on probing, and plaque, were recorded and radiographic assessments were performed.

STATISTICAL ANALYSIS

 Comparisons of aMMP-8 levels and clinical parameters were analyzed by the Kruskal-Wallis test and the pairwise post hoc Dunn-Bonferroni test. A receiver operating curve analysis was used to analyze the diagnostic ability of aMMP-8 and the correlation between aMMP-8 and probing depth of the sampled site was sought by Spearman's rho and the coefficient of determination (R 2).

RESULTS

 Statistical analysis revealed statistically significant differences of aMMP-8 levels between the healthy and the mucositis and peri-implantitis groups, and between the mucositis and the peri-implantitis groups. Increasing probing depths of the sampled site and aMMP-8 levels were significantly correlated.

CONCLUSIONS

 These data suggest that the aMMP-8 PoC test can be a beneficial adjunctive tool for early identification and screening of the risk of peri-implant diseases and progression.

Testosterone replacement relieves ligature-induced periodontitis by mitigating inflammation, increasing pro-resolving markers and promoting angiogenesis in rats: A preclinical study

OBJECTIVES

This study aimed to evaluate the inflammatory profile as well as the resolution of inflammation in a ligature-induced periodontal inflammation in rats with depletion and/or supraphysiological testosterone replacement.

DESIGN

Sixty male rats (Holtzman) were used in the present study. Study groups were created as following: (1) Sham (no testicle removal); (2) Orchiectomy (OCX), 3) OCX + Testosterone (OCX + T); (4) Sham + Ligature (SH + L); (5) OCX+L; and 6) OCX + T + L. The surgeries were performed on day 1, and testosterone was administered weekly since day 1. On day 15, a cotton ligature was placed around the lower first molars and maintained for 15 days. Morphological changes in periodontal tissues were determined by histopathological analysis. Immunohistochemistry (factor VIII) and immunoenzymatic assay were performed to evaluate angiogenesis process and (pro- and anti-) inflammatory markers, respectively.

RESULTS

Ligature promoted a marked inflammatory gingival infiltrate and bone loss (P < 0.05). Supraphysiological testosterone treatment increased the percentage of blood vessels, extracellular matrix and fibroblasts in the presence and absence of periodontal inflammation (P < 0.05). A high dose of testosterone increased factor VIII+ blood vessels and IL-10 expression in inflamed gingival tissue, while PGE₂, LXA₄ and MPO were reduced as a result of supraphysiological testosterone administration (P < 0.05).

CONCLUSIONS

These results, in our experimental model, suggest that supraphysiological testosterone treatment stimulated gingival tissue repair during ligature-induced periodontitis, and it seems to be related to an anti-inflammatory and pro-resolutive mechanism resulting by the modulatory effect on PGE₂ and IL-10 related to an enhanced angiogenesis.

Potential Impact of Prosthetic Biomaterials on the Periodontium: A Comprehensive Review

The success of a prosthetic treatment is closely related to the periodontal health of the individual. The aim of this article was to review and present the importance of prosthetic restorative materials on the condition of the periodontium, the changes that occur in the composition of the subgingival microbiota and the levels of inflammatory markers in gingival crevicular fluid. Articles on the influence of different prosthetic restorative materials on subgingival microbiota and proinflammatory cytokines were searched for using the keywords "prosthetic biomaterials", "fixed prosthesis", "periodontal health", "subgingival microbiota", "periodontal biomarkers" and "gingival crevicular fluid" in PubMed/Medline, Science Direct, Scopus and Google Scholar. The type of material used for prosthesis fabrication together with poor marginal and internal fit can result in changes in the composition of the subgingival microbiota, as well as increased accumulation and retention of dentobacterial plaque, thus favoring the development of periodontal disease and prosthetic treatment failure. Biological markers have helped to understand the inflammatory response of different prosthetic materials on periodontal tissues with the main purpose of improving their clinical application in patients who need them. Metal-free ceramic prostheses induce a lower inflammatory response regardless of the fabrication method; however, the use of CAD/CAM systems is recommended for their fabrication. In addition, it is presumed that metal-ceramic prostheses cause changes in the composition of the subgingival microbiota producing a more dysbiotic biofilm with a higher prevalence of periodontopathogenic bacteria, which may further favor periodontal deterioration.

Smart Bacteria-Responsive Drug Delivery Systems in Medical Implants

With the rapid development of implantable biomaterials, the rising risk of bacterial infections has drawn widespread concern. Due to the high recurrence rate of bacterial infections and the issue of antibiotic resistance, the common treatments of peri-implant infections cannot meet the demand. In this context, stimuli-responsive biomaterials have attracted attention because of their great potential to spontaneously modulate the drug releasing rate. Numerous smart bacteria-responsive drug delivery systems (DDSs) have, therefore, been designed to temporally and spatially release antibacterial agents from the implants in an autonomous manner at the infected sites. In this review, we summarized recent advances in bacteria-responsive DDSs used for combating bacterial infections, mainly according to the different trigger modes, including physical stimuli-responsive, virulence-factor-responsive, host-immune-response responsive and their combinations. It is believed that the smart bacteria-responsive DDSs will become the next generation of mainstream antibacterial therapies.

Repeated Daily Use of Dual-Light Antibacterial Photodynamic Therapy in Periodontal Disease—A Case Report

Good oral hygiene at home is the foundation for optimal treatment response and long-term periodontal disease control. Antibacterial photodynamic therapy (aPDT) provides a very potent adjunctive treatment for plaque control. However, the literature regarding repeated aPDT use is sparse. aPDT has been a modality applied mainly in the dental office environment, and when applied once a year or every few months, the results have been usually disappointing. Recently, LED development has brought aPDT for repeated and practical use at home. We present the very positive results and clinical outcome of daily applied dual-light aPDT-technology treatment in conjunction with mechanical cleaning of a 78-year-old male patient with severe periodontal disease (Stage IV and Grade B).

Host and bacterial factors linking periodontitis and rheumatoid arthritis

Observations from numerous clinical, epidemiological and serological studies link periodontitis with severity and progression of rheumatoid arthritis. The strong association is observed despite totally different aetiology of these two diseases, periodontitis being driven by dysbiotic microbial flora on the tooth surface below the gum line, while rheumatoid arthritis being the autoimmune disease powered by anti-citrullinated protein antibodies (ACPAs). Here we discuss genetic and environmental risk factors underlying development of both diseases with special emphasis on bacteria implicated in pathogenicity of periodontitis. Individual periodontal pathogens and their virulence factors are argued as potentially contributing to putative causative link between periodontal infection and initiation of a chain of events leading to breakdown of immunotolerance and development of ACPAs. In this respect peptidylarginine deiminase, an enzyme unique among prokaryotes for Porphyromonas gingivalis, is elaborated as a potential mechanistic link between this major periodontal pathogen and initiation of rheumatoid arthritis development.

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

Background

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

Methods

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

Results

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

Conclusion

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

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.

The Role of Matrix Metalloproteinases (MMP-8, MMP-9, MMP-13) in Periodontal and Peri-Implant Pathological Processes

Severe periodontitis, a destructive inflammatory disease of the supporting tissues of the teeth, ranks sixth in terms of global spread, affecting about 11% of the population. Metalloproteinases (MMPs) are extracellular matrix (ECM) macromolecules that are important in cellular development and morphogenesis, and they are capable of activating growth factors in their proximity, cell surface receptors, and adhesion molecules. MMPs are part of a major family of zinc-dependent endopeptidases, and their activity is modulated and regulated by certain inhibitors known as tissue metalloproteinase inhibitors (TIMPs). Because type I collagen is the major component of the periodontal extracellular matrix, special attention has been paid to the role of collagenases, especially MMP-8 and MMP-13 and gelatinases, MMP-2 and MMP-9, in periodontal diseases. In fact, MMP-8 (or collagenase 2) is currently one of the most promising biomarkers for periodontitis in oral fluids. Among them, salivary MMP-9 has been shown to be a more sensitive marker for periodontal inflammation during orthodontic treatment, which opens new perspectives in reducing periodontal hazards during such treatments. Both MMP-8 and MMP-9 are extremely valuable diagnostic tools in treating periodontitis, and future studies and healthcare policies should focus on implementing more accessible methods of chairside testing in order to reduce the prevalence of this disease.

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.

TNF-α, IL-1β, MMP-8 Crevicular Profile in Patients with Chronic Kidney Disease and Periodontitis

Increasing evidence sustains the potential of periodontitis as a risk factor for chronic kidney disease (CKD). Our study aimed to analyze several periodontal specific inflammatory biomarkers within the gingival crevicular fluid (GCF) of patients with CKD, compared to patients with normal kidney function, providing an inflammatory profile of the dialysis patient. The study comprised 79 patients divided into: group 1 (59 subjects with periodontitis and CKD) and group 2 (20 patients with periodontitis, without other systemic conditions). Clinical diagnosis was performed via dental and periodontal examination. GCF samples were collected from each patient, and the levels of TNF-α, IL-1β and MMP-8 were determined by using ELISA assay. In group 1, the average values were: 22.85 ± 5.87 pg/mL for TNF-α, 33.00 ± 39.68 pg/mL for IL-1β and 18.80 ± 27.75 ng/mL for MMP-8. In group 2, the mean values were: 2.10 ± 1.34 pg/mL for TNF-α, 0.71 ± 2.42 pg/mL for IL-1β and 5.35 ± 0.37 ng/mL for MMP-8. Statistical analysis revealed significant differences between groups as referring to all three biomarkers and, TNF-α and MMP-8, in certain stages of periodontitis. The level of TNF-α, IL-1β and MMP-8 points out the increased inflammatory status of the dialysis patient with PD, supporting the mutual connection of the two pathologies.

A Mini Review: The Potential Biomarkers for Non-invasive Diagnosis of Pulpal Inflammation

For assessing the adequacy of vital pulp therapy for an inflamed pulp, the use of non-invasive diagnostic tools is necessary to avoid further damage to the teeth. Detection of biomarkers that are indicative of the inflammatory status in pulp can be a promising tool for this purpose. These biomarkers need to be reliably correlated with pulpal inflammation and to be easily detected without pulp exposure. This mini-review article aims to review biomarkers that are present in gingival crevicular fluid (GCF) in inflamed pulp conditions. Several studies have reported the availability of various biomarkers including cytokines, proteases, elastase, neuropeptides, and growth factors. Non-invasive pulpal diagnostic methods will be useful as well to determine reversibility, irreversibility, or necrosis of inflamed pulp. These types of molecular diagnoses via analyzing the proteome have revolutionized the medical field, and are one of the most promising empirical methodologies that a clinician can utilize for the proactive identification of pulpal disease.

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.

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 accuracy of a point-of-care aMMP-8 test in the discrimination of periodontal health and disease

Aim

To assess the diagnostic utility of an oral rinse active matrix metalloproteinase‐8 (aMMP‐8) point‐of‐care test (POCT) for differentiating periodontal health, gingivitis, as well as different stages and grades of periodontitis.

Materials & Methods

The aMMP‐8 index test was undertaken in 408 consecutive adults, followed by a full‐mouth periodontal examination. The reference standard was the 2017 World Workshop classification of periodontal diseases. Sensitivity, specificity, and the area under the receiver operating characteristic curve (AUROC) were assessed.

Results

68.6% of the participants were diagnosed with periodontitis, including Stages I (15.9%), II (15.9%), III (29.7%) and IV (7.1%). A positive aMMP‐8 POCT was associated with periodontitis after adjusting for age, gender, tobacco smoking and systemic diseases, while it was unable to differentiate among the stages/grades of periodontitis and between gingivitis/periodontal health. This test showed a sensitivity of 33.2% and a specificity of 93.0% for detecting periodontitis (threshold level >10 ng/ml). The levels of aMMP‐8 adjusted by the number of teeth present (aMMP‐8/NTP) performed better for periodontitis (sensitivity: 67.1%; specificity: 68.8%). Notably, aMMP‐8/NTP were strongly predictive for Stage IV periodontitis (threshold level =0.4312 ng/ml) (sensitivity: 89.7%; specificity: 73.6%; and AUROC: 0.856). The test performance greatly improved in combination with age and smoking, with a sensitivity of 82.5%, a specificity of 84.4%, and an AUROC of 0.883.

Conclusion

This aMMP‐8 POCT is able to detect periodontitis with better specificity than sensitivity across the spectrum of its severity. This test may be useful for periodontal screening in conjunction with subject characteristics and/or other sensitive screening tools. Further validation studies are needed.

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

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

An Unexplored Pharmacologic/Diagnostic Strategy for Peri-Implantitis: A Protocol Proposal

Dental implants are widely utilized for the replacement of missing teeth and are increasingly being placed in patients with systemic diseases, as well as in those who are medically healthy. Furthermore, it is recognized that peri-implant mucositis and peri-implantitis are highly prevalent, affecting large numbers of patients with implants, and it is pertinent to consider whether there may be any systemic impact of these conditions, given that there are known links between periodontitis and a number of chronic inflammatory diseases. In this article, we propose that the potential systemic complications of peri-implant diseases should be investigated in future clinical research, together with studies to identify whether systemically-administered host modulation therapies (HMTs) may be of benefit in the treatment of peri-implant diseases. These “HMTs” may prove a useful adjunct to routinely employed debridement and disinfection protocols, as well as potentially being of benefit in reducing risks of systemic complications. We also consider the use of chair-side diagnostic tests for active matrix metalloproteinase-8 (aMMP-8) in the detection of peri-implant disease given the ability of such tests to detect active tissue breakdown associated with peri-implantitis and periodontitis before conventional clinical and radiographic measurements indicate pathologic changes. These novel diagnostic and therapeutic strategies are relevant to consider as they may improve the management of peri-implant disease (beyond local debridement procedures), especially in those patients in whom systemic inflammation might be of concern.

In situ gel drug delivery system for periodontitis: an insight review

Background

Periodontitis is a microbial disease that leads to inflammation in the tooth-supporting tissues of the oral cavity that is common among the elderly. It is initiated by oral inflammation induced by bacterial dysbiosis. Choosing an appropriate antimicrobial agent with the right course of drug administration is the key to successful periodontal therapy. In recent times, with more biomarkers and the development of new technologies, several point-of-care testing (POCT) platforms have been developed for the diagnosis and monitoring of periodontitis. This review focuses on oral microbiology and the pathogenesis of periodontitis as well as recent insights into the in situ gel system for periodontitis.

Design

An exhaustive search was conducted in the following scientific databases Science Direct, Springer, Pub Med, and Google Scholar to review all relevant literatures. This is a comprehensive narrative review of the literature, summarizing the perspectives of the authors.

Results

Novel in situ forming gel is introduced at the site that shows a promising potential to overcome one of the main practical obstacles associated with the treatment of local periodontitis: partial adhesion to the surrounding tissue, causing in the accidental expulsion of at least parts of the implants from patient’s pockets. This results in a large residence time of the system at the site of action and uncertainty of the final exposure to the drug.

Conclusion

From the reviewed literature, it is concluded that experimental evidence suggests that the in situ gel-forming systems can be useful in treating several common diseases of the oral cavity. Future research should focus on clinical studies to be performed for the in situ gel to make a significant contribution to periodontitis.

Graphical abstract

Silencing matrix metalloproteinase-13 (Mmp-13) reduces inflammatory bone resorption associated with LPS-induced periodontal disease in vivo

OBJECTIVES

The aim of this study was to evaluate the effect of specific inhibition of MMP-13 on inflammation and inflammatory bone resorption in a murine model of lipopolysaccharide (LPS)-induced periodontitis.

MATERIALS AND METHODS

Periodontitis was induced in mice by micro-injections of LPS into the gingival tissues adjacent to the palatal surfaces of maxillary molars twice a week for 15 days. Matrix metalloproteinase-13 (Mmp-13) shRNA or a specific biochemical inhibitor were also injected into the same sites in alternating days with the LPS injections. Efficacy of shRNA-mediated silencing of Mmp-13 was verified by quantitative real-time polymerase chain reaction (qPCR) and immunoblot. Bone resorption was assessed by microcomputed tomography (uCT). Histological sections stained with hematoxylin/eosin (H/E) were used in the stereometric analysis of the inflammatory infiltrate. Gingival tissues were used to evaluate expression of Mmp-13, Il-6, Tnf-α, Ptgs2, and Rankl (qPCR). Protein levels of TGF-β and IL-10 in the tissues were determined by enzyme-linked immunosorbent assays (ELISA) or by MMP-13 and p38 immunoblot.

RESULTS

Silencing Mmp-13 expression reduced bone resorption significantly. Expression of Mmp-13, Il-6, and Tnf-α, as well as the protein levels of IL-6 and TNF-α, was reduced in the animals treated with adenovirus-delivered shRNA; however, these effects were not associated with modulation of p38 MAPK signaling. Interestingly, inhibition Mmp-13 did not affect the severity of inflammatory infiltrate.

CONCLUSIONS

Site-specific inhibition of MMP-13 reduced bone resorption and production of inflammatory mediators associated with periodontal disease.

CLINICAL RELEVANCE

The results suggest that site-specific inhibition of MMP-13 may be an interesting strategy to modulate inflammation and reduce bone resorption in osteolytic inflammatory diseases.

MMP-8, TRAP-5, and OPG Levels in GCF Diagnostic Potential to Discriminate between Healthy Patients', Mild and Severe Periodontitis Sites

Biomarkers represent promising aids in periodontitis, host-mediate diseases of the tooth-supporting tissues. We assessed the diagnostic potential of matrix metalloproteinase-8 (MMP-8), tartrate-resistant acid phosphatase-5 (TRAP-5), and osteoprotegerin (OPG) to discriminate between healthy patients’, mild and severe periodontitis sites. Thirty-one otherwise healthy volunteers with and without periodontal disease were enrolled at the Faculty of Dentistry, University of Chile. Periodontal parameters were examined and gingival crevicular fluid was sampled from mild periodontitis sites (M; n = 42), severe periodontitis sites (S; n = 59), and healthy volunteer sites (H; n = 30). TRAP-5 and OPG were determined by commercial multiplex assay and MMP-8 by the immunofluorometric (IFMA) method. STATA software was used. All biomarkers showed a good discrimination performance. MMP-8 had the overall best performance in regression models and Receiver Operating Characteristic (ROC) curves, with high discrimination of healthy from periodontitis sites (area under the curve (AUC) = 0.901). OPG showed a very high diagnostic precision (AUC ≥ 0.95) to identify severe periodontitis sites (S versus H + M), while TRAP-5 identified both healthy and severe sites. As conclusions, MMP-8, TRAP-5, and OPG present a high precision potential in the identification of periodontal disease destruction, with MMP-8 as the most accurate diagnostic biomarker.

Diagnostic Accuracy of Oral Fluids Biomarker Profile to Determine the Current and Future Status of Periodontal and Peri-Implant Diseases

Severe periodontitis is ranked as the sixth most prevalent disease affecting humankind, with an estimated 740 million people affected worldwide. The diagnosis of periodontal diseases mainly relies upon assessment of conventional clinical parameters. However, these parameters reflect past, rather than current, clinical status or future disease progression and, likely, outcome of periodontal treatment. Specific and sensitive biomarkers for periodontal diseases have been examined widely to address these issues and some biomarkers have been translated as point-of-care (PoC) tests. The aim of this review was to provide an update on PoC tests for use in the diagnosis and management of periodontal diseases. Among the PoC tests developed so far, active matrix metalloproteinase-8 has shown promising results in terms of diagnostic and prognostic values. However, further studies are required to increase the sensitivity and specificity via combining more than one biomarker and merging these test kits with periodontal risk assessment tools. Furthermore, the validity of these test kits needs to be investigated by applying the results in further independent studies and the impact on these test kits’, together with the results of risk factors for periodontal diseases, such as diabetes and smoking, also needs to be examined.

Molecular signatures of extracellular vesicles in oral fluids of periodontitis patients

OBJECTIVE

To characterize extracellular vesicles (EVs) in gingival crevicular fluid (GCF) and saliva samples from healthy/gingivitis and periodontitis patients and correlate them with clinical inflammatory periodontal parameters.

MATERIAL AND METHOD

An exploratory study, including 86 subjects, was conducted. Clinical and periodontal data were recorded, and oral fluid samples were obtained. EVs were precipitated by ExoQuick-TC™ and characterized by nanoparticle tracking (NanoSight™), Western blot (WB), transmission electron microscopy (TEM), and ELISA analysis.

RESULTS

TEM showed nanoparticles morphologically compatible with EVs, and WB analysis revealed bands of specific EV markers (CD9, TSG101, and Alix) in both oral fluids of periodontitis and healthy/gingivitis subjects. The total concentration of EVs in GCF was increased in periodontitis patients compared to healthy/gingivitis subjects (p = .017). However, we did not observe differences in the EV concentration of saliva samples (p = .190). The size of GCF-EVs was 144.2 nm in periodontitis and 160.35 nm in healthy/gingivitis patients (p = .038). The CD63 exosome marker was increased in GCF of periodontitis patients (p = .00001). The total concentration of EVs in GCF was correlated with bleeding on probing (rho = 0.63, p = .002), periodontal probing depth (rho = 0.56, p = .009), and clinical attachment level (rho = 0.48, p = .030).

CONCLUSION

Periodontitis patients have an increased concentration of EVs in GCF, and their role in periodontitis should be clarified.

Clinical and Biochemical Evaluation of the Effect of Diode Laser Treatment Compared to the Non-surgical and Surgical Treatment of Periodontal Diseases

Background:

Periodontal therapy consists of eliminating the inflammation, treating periodontal pockets, motivating the patient for oral hygiene, and, if necessary, for surgical treatment. Recently, the application of a diode laser is widely being investigated for periodontal disease treatment.

Objective:

The analysis and evaluation of the clinical and biochemical impact of diode laser periodontal treatment, compared to either surgical or non-surgical, therapy, was the aim of this study.

Methods:

The study involved 80 patients older than 18 with at least 20 teeth. Evaluation of periodontal parameters was done conveniently on a single-rooted tooth (incisive, canine, premolar) on six surfaces, before the start of periodontal therapy, and after three, and six months. The laser used in the study was a diode laser with a wavelength of 980 nm. Digital X-rays were taken for bone level evaluation before and after the treatment. The presence of a bone destruction mediator (Matrix metalloproteinase-8 - MMP-8) was evaluated by the dipstick immunoassay test. Biochemical analysis and radiographic measurements were evaluated at the baseline and six months after the treatment. The statistical analysis included χ2-test and one-way ANOVA.

Results:

The results of this study showed that diode laser treatment was more effective in reducing periodontal clinical parameters, lowering MMP-8 levels and reducing the bone loss, compared to the group treated with scaling and root planning, or with a surgical approach.

Conclusion:

Diode laser may be considered as an effective alternative for periodontal treatment, with benefits in clinical and biochemical parameters.

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.

Effectiveness of Probiotic Lozenges in Periodontal Management of Chronic Periodontitis Patients: Clinical and Immunological Study

OBJECTIVE

 The main purpose of this article was to evaluate the effect of probiotics used as an adjunctive to scaling and root planing (SRP) on the periodontal parameters and matrix metalloproteinase-8 (MMP-8) levels in gingival crevicular fluid (GCF) of chronic periodontitis patients.

MATERIALS AND METHODS

 A total of 25 chronic periodontitis patients who completed the treatment course of 40 subjects, aged 25 to 58 years, participated in this study. They were categorized into two groups: the first group was treated by SRP while the second group was treated by SRP and probiotic lozenges twice a day for 30 days. All patients were evaluated clinically by measuring the plaque index, bleeding index (BI), pocket depth, clinical attachment loss, and immunologically by assaying GCF/MMP-8 at baseline and 30 days after periodontal management.

RESULTS

 There was a significant improvement in periodontal parameters after SRP treatment with and without probiotic lozenges in both groups. However, there was a significant decrease in the BI (p = 0.05) in SRP and probiotic lozenges group after 30 days compared with SRP alone. In addition, there was a significant decrease in GCF/MMP-8 levels after 30 days in patients managed by SRP only (p = 0.017) compared with the baseline in both groups, whereas a highly significant decrease in patients treated by SRP and probiotics (p = 0.001).

CONCLUSION

 The current study suggested that the probiotics might have a beneficial effect on clinical and immunological outcomes in the management of chronic periodontitis patients. Further research is needed on a large-scale population and for a long recall time to confirm the response to probiotics as an adjunctive to SRP.

Biomarker for Asymptomatic Apical Periodontitis in Gingival Crevicular Fluid: aMMP-8

Objectives  Asymptomatic apical periodontitis (AAP) is one of the most widespread chronic inflammatory diseases in the field of dental medicine. Active matrix metalloproteinase (aMMP-8) previously demonstrated diagnostic potential as a biomarker for AAP in gingival crevicular fluid (GCF). The aim of this study was to determine the levels and diagnostic accuracy of aMMP-8 in GCF from teeth with AAP.

Materials and Methods  In this cross-sectional study, GCF samples were obtained from teeth with AAP (sample group, n = 31) and their contralateral teeth (control group, n = 31). Clinical and cone beam computed tomography (CBCT) parameters were used for the diagnosis and assessment of AAP and the determination of clinically healthy marginal periodontal tissues. One pool GCF sample per tooth was obtained from the whole crevice’s perimeter. aMMP-8 levels were determined by enzyme-linked immunosorbent assay (ELISA).

Statistical Analysis  Wilcoxon signed ranks test and Spearman rank correlation coefficient (rs) were used as statistical tools. The significance level was set at p < .05.

Results  The two groups demonstrated biomarker levels corresponding to a healthy marginal periodontal tissue. aMMP-8 levels were statistically and significantly higher in the samples collected from teeth with AAP. Lesions with greater volume showed correspondingly larger diameters. No statistically significant correlation between aMMP-8 levels and lesions’ volume or diameter was discovered.

Conclusion  GCF composition is modified by AAP only to a minimal extent. Further research is needed to substantiate the utilization of aMMP-8 as a potential biomarker for the diagnosis of the disease as well as to explore its relationship with other biomarkers.

Active MMP-8 (aMMP-8) as a Grading and Staging Biomarker in the Periodontitis Classification

The aim of this study was to investigate the utility of incorporating active matrix metalloproteinase-8 (aMMP-8) as a biomarker into the new periodontitis classification system (stage/grade) presented in 2018. This study included 150 Greek adults aged 25-78, of whom 74 were men and 76 women. Participants were tested with an aMMP-8 point-of-care mouthrinse test, after which a full-mouth clinical examination was performed to assess their periodontal and oral health. The aMMP-8 levels in mouthrinse were significantly lower among healthy patients compared with patients in more severe periodontitis stages and grades (Kruskal-Wallis test and Dunn-Bonferroni test for pairwise post-hoc comparisons; p < 0.01 and p < 0.05, respectively). Furthermore, aMMP-8 levels were less correlated with plaque levels than bleeding on probing (BOP) (Spearman's rho = 0.269, p < 0.001; Spearman's rho = 0.586, p < 0.001); respectively). Thus, aMMP-8 was more robust to the confounding effects of oral hygiene than traditional periodontal parameter bleeding on probing. The aMMP-8 point-of-care mouthrinse test can be utilized as an adjunctive and preventive diagnostic tool to identify periodontal disease, classified by stage and grade, and ongoing periodontal breakdown chairside in clinical practice in only 5 min. Overall, integrating aMMP-8 into the new periodontitis classification system seems beneficial.

Association of the salivary triggering receptor expressed on myeloid cells/its ligand peptidoglycan recognition protein 1 axis with oral inflammation in kidney disease

BACKGROUND

Triggering receptor expressed on myeloid cells (TREM-1) is a cell-surface receptor involved in amplification of inflammatory response to bacterial infections, along with its ligand peptidoglycan recognition protein 1 (PGLYRP1). TREM-1 is shed by matrix metalloproteinases (MMPs) to its soluble (s) form. The aim of the study is to investigate association of sTREM-1 and PGLYRP1 with oral inflammatory burden among patients with chronic kidney disease (CKD) at predialysis and posttransplantation stages.

METHODS

One hundred forty-four patients with CKD were examined at predialysis, and oral infection foci were treated prior to kidney transplantation. Fifty-three patients were available for follow-up after transplantation. Oral inflammatory burden was assessed by the Periodontal Inflammatory Burden Index (PIBI) and Total Dental Index. sTREM-1, PGLYRP1, and interleukin (IL)-1β were measured in saliva by enzyme-linked immunosorbent assay, and MMP-8 was measured by immunofluorometric assay.

RESULTS

In the predialysis stage, sTREM-1 and PGLYRP1 were positively associated with IL-1β, MMP-8, and PIBI. More specifically, patients with deeper probing depth (PD) (at least two sites with ≥6 mm) had higher concentrations of salivary sTREM-1 and PGLYRP1 compared with those with shallower PD. Higher concentrations of PGLYRP1 and IL-1β were associated with a higher number of teeth (> 25). On follow-up, higher PGLYRP1 and sTREM-1 were associated with one or more sites with ≥4 mm PD.

CONCLUSIONS

sTREM-1 and PGLYRP1 are elevated in patients with CKD with poor oral health and positively correlate with number of active periodontal pockets after oral infection therapy. Moreover, they positively correlate with MMP-8 and IL-1β. Hence, the salivary sTREM-1/PGLYRP1 axis could be useful as a diagnostic marker for oral infection within patients with CKD.

The Connection of Periodontal Disease and Diabetes Mellitus: The Role of Matrix Metalloproteinases and Oxidative Stress

Diabetes mellitus, a chronic disease considered by the World Health Organization to be an epidemic, is now recognized as one of the factors behind the onset of periodontal disease. The connection between periodontal disease, which is an irreversible inflammatory disease of the supporting tissue of the teeth, and systemic diseases is reflected in the existence of common risk factors, subgingival dental biofilm, as a constant source of proinflamma-tory cytokines synthesized intensely in inflammatory periodontium. Diabetes mellitus leads to increased oxidative stress in periodontal tissues causing worsening of the disease and periodontopathy exacerbates deficiency of pancreatic β-cells. The most important role in primary inflammatory response in the pathogenesis of periodontopathy is played by neutrophils. Neutrophils cause periodontium destruction by the release of enzymes (matrix metalloproteinases), cytotoxic substances (free radicals, reactive oxygen and nitrogen species) and the expression of membrane receptors. Matrix metalloproteinases within the “protease network” are critical to many physiological and pathological processes, including immunity, inflammation, bone resorption and wound healing. Matrix metalloproteinases levels are elevated in patients with metabolic syndrome and diabetes mellitus, which may contribute to more frequent complications. In this paper, the review of available literature data shows the correlation between periodontal disease and diabetes mellitus, as well as the role of matrix metalloproteinases and oxidative stress in these. In this regard, determining the value of matrix metalloproteinases may be helpful in the diagnosis of periodontal disease complicated by diabetes mellitus. Also, the parameters of oxidative stress could help to clarify the mechanisms of pathogenesis and etiology of periodontal disease, or indicate the potential benefit of antioxidant supplementation in these individuals. As the role of matrix metalloproteinases has not been fully clarified in the pathogenesis of periodontopathy, additional studies will be needed to indicate their importance.

Azurocidin in gingival crevicular fluid as a potential biomarker of chronic periodontitis

BACKGROUND AND OBJECTIVE

Azurocidin is a neutrophil-derived protein in gingival crevicular fluid (GCF) which, according to relevant studies, might correlate with periodontal disease. The aim of the present study was to evaluate azurocidin as a potential biomarker for chronic periodontitis.

MATERIAL AND METHODS

One hundred and one patients participated in the study, divided into two groups. Forty-eight were included in the periodontally healthy group (HP) and fifty-three in the chronic periodontitis group (CP). Clinical indices included probing depth (PD), recession (REC), clinical attachment level (CAL), bleeding on probing (BOP) and plaque (PL). Pooled GCF samples were collected with paper strips, freezed in liquid nitrogen (-196°C), stored at -80°C, and the levels of azurocidin were analyzed with ELISA. Values were transformed and expressed for comparisons in pg/30 s sample. Statistical comparisons were performed using non-parametric tests (Mann-Whitney) at the 0.05 level. Furthermore, the diagnostic accuracy of the procedure was assessed with receiver operator characteristic curves (ROC), areas under the curve (AUC), and the Youden's J Index calculated.

RESULTS

Demographic data were comparable between the two groups. Clinical parameters and the levels of azurocidin were statistically significantly higher in the CP group when compared to the HP group (Mann-Whitney test, P < .05). Quantitative data from ELISA demonstrated a high diagnostic accuracy of azurocidin, with AUC calculated higher than 0.9 at the 0.000 level.

CONCLUSION

Azurocidin in GCF is a promising biomarker for periodontal disease. The results of the present study agree with previous studies in the literature showing an up-regulated trend in the levels of azurocidin in periodontitis patients.

Biomarkers of oral inflammation in perinatally HIV-infected and perinatally HIV-exposed, uninfected youth

AIM

To examine oral biomarkers that have been associated with periodontal disease progression in HIV-infected adults in perinatally HIV-infected and HIV-exposed but uninfected youth.

MATERIAL AND METHODS

This was a cross-sectional, multicentre substudy of youth participating in the Oral Health Pediatric HIV/AIDS Cohort study. Gingival crevicular fluid repository samples from participants with and without periodontal disease (using Gingival Index [GI] and Bleeding on Probing [BOP] parameters on dental examination) were tested for concentration levels of inflammatory biomarkers. Associations were assessed using Wilcoxon test and Spearman correlation.

RESULTS

For perinatal HIV youth (n = 129), the markers consistently elevated (p < .05) in sites with GI ≥2 and in sites with BOP were interleukin-1β, 6 and 13, macrophage inflammatory protein-1α and metalloproteinase-9. Serum tumour necrosis factor-α and soluble CD14 were positively correlated with a summary count of elevated cytokines. No associations were seen among HIV-uninfected subjects (n = 71).

CONCLUSIONS

The association of oral biomarkers of inflammation with clinical indicators of periodontal inflammation and systemic immune activation suggests that perinatal HIV-infected youth may be at higher risk for developing significant periodontal disease, associated with tooth loss and HIV progression. More frequent dental care of this group is needed to prevent potential periodontal progression.

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.

Adjunctive Effects of a Sub-Antimicrobial Dose of Doxycycline on Clinical Parameters and Potential Biomarkers of Periodontal Tissue Catabolism

Objectives: The aim of the present randomized, double-blind, placebo-controlled, parallel-arm study was to examine the effectiveness of a sub-antimicrobial dose of doxycycline (SDD) in combination with nonsurgical periodontal therapy, compared to nonsurgical periodontal therapy alone, on potential gingival crevicular fluid (GCF) biomarkers of periodontal tissue catabolism related to the clinical outcomes over a 12-month period. Materials and Methods: GCF was collected and clinical parameters were recorded from 30 periodontitis patients randomized either to an SDD or placebo group. The SDD group received SDD (20 mg) b.i.d for 3 months plus scaling and root planing (SRP), while the placebo group was given placebo capsules b.i.d for 3 months plus SRP. The patients were evaluated every 3 months during the 12-month study period. At each visit, clinical parameters and GCF sampling were repeated. Matrix metalloproteinase (MMP)-8, MMP-9, MMP-13, myeloperoxidase (MPO), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase-5 (TRAP-5) were determined by IFMA and ELISA. Results: Significant improvements were observed in all clinical parameters in both groups over 12 months (p < 0.0125) while the SDD group showed significantly better reduction in gingival index (GI) and pocket depth and a gain in clinical attachment compared to the placebo group (p < 0.05). GCF MMP-8 and OPG levels significantly reduced in the SDD group compared to baseline (p < 0.05). GCF MMP-9 significantly decreased in both groups compared to baseline (p < 0.05). GCF MPO significantly decreased at 3 and 9 months in the SDD group, while it significantly decreased at 6 months in the placebo group (p < 0.05). TRAP and MMP-13 could be detected in none of the samples. Conclusions: The present results indicate that three months of adjunctive usage of SDD to nonsurgical periodontal therapy compared to nonsurgical periodontal therapy alone in periodontitis patients results in further improvement of clinical periodontal parameters and GCF markers of periodontal tissue breakdown over a 12-month period. Beneficial effects of adjunctive SDD therapy is likely to be related to the reduced levels of two major periodontitis-associated MMPs, MMP-8 and -9, and their potential oxidative activator MPO.

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.

Effects of diode laser application on inflammation and mpo in periodontal tissues in a rat model

Objective

In this study, we aimed to histologically and immunologically evaluate the effect of diode laser treatment when applied adjunctive to scaling and root planing (SRP) in an experimental periodontitis model.

Materials and methods

We used Wistar-Albino rats (n=60) with average weight of 230 g. Experimental periodontitis was induced by ligature at the right and left first mandibular molar teeth in all rats. After 11 days, the ligature was removed and rats were divided into two groups. The control group (n=30) received only SRP treatment, while the laser group (n=30) received a diode laser (GaAlAs, 810 nm, 1 W, 10 J, 20 s) treatment adjunctive to SRP. Ten rats in each group were sacrificed after 7, 15, and 30 days. Histopathological examination was performed in the left mandible of rats. Myeloperoxidase (MPO) was evaluated by western blot in the gingival specimens from the right mandible.

Results

MPO levels in the laser group were statistically significantly lower compared with the control group (p≤0.05). There was no statistically significance at any time between MPO levels in the control group (p>0.05). MPO levels in the laser group at the 7^th day were statistically significantly higher compared to the 15^th (p≤0.05) and the 30^th day (p≤0.05). Inflammatory cell infiltration decreased over time in both groups and was statistically significantly lower in the laser group than in the control group at all times (p≤0.01).

Conclusions

Within the limits of this study, we suggest that diode laser application is an adjunctive treatment because it reduced inflammation and MPO when applied in addition to SRP. On the other hand, more studies are needed for the assessment of the effects of diode laser application to periodontal tissues.

High-throughput proteomic analysis of candidate biomarker changes in gingival crevicular fluid after treatment of chronic periodontitis

BACKGROUND AND OBJECTIVE

Untargeted, high-throughput proteomics methodologies have great potential to aid in identifying biomarkers for the diagnosis of periodontal disease. The application of such methods to the discovery of candidate biomarkers for the resolution of periodontal inflammation after periodontal therapy has been investigated.

MATERIAL AND METHODS

Gingival crevicular fluid samples were collected from 10 patients diagnosed with chronic periodontitis at baseline and 1, 5, 9 and 13 weeks after completion of mechanical periodontal treatment. Clinical indices of periodontal disease, including probing depth, recession, clinical attachment level and bleeding on probing, were recorded at baseline and 13 weeks. Samples were analyzed using an online liquid chromatography-nanoelectrospray-hybrid ion trap-Orbitrap mass spectrometer. Spectra were processed with the PILOT_PROTEIN proteomics software suite.

RESULTS

Clinical parameters were significantly improved 13 weeks after treatment (Wilcoxon signed ranks test, P < .05). From the substantial number of identified proteins, a small subset was extracted by filter methods that included temporal pattern matching, logistic function fitting and mixed-integer linear optimization. This subset includes azurocidin, lysozyme C and myosin-9 as candidate biomarkers prominent at baseline and alpha-smooth muscle actin as prominent 13 weeks after treatment. Cross-validation studies yielded average predictive accuracy and area under the curve of 0.900 and 0.930, respectively.

CONCLUSION

High-throughput proteomic analysis can contribute to identifying endpoints of periodontal therapy. These candidate biomarkers should be evaluated for clinical efficacy.