Periodontal disease and targeted prevention using aMMP-8 point-of-care oral fluid analytics in the COVID-19 era

Association between sequelae of COVID-19 with periodontal disease and obesity: A cross-sectional study

BACKGROUND

To assess the sequelae of coronavirus disease 2019 (COVID-19) and associated factors, such as obesity and periodontitis in adults.

METHODS

The study included 128 individuals aged ≥35 years with a history of a diagnosis of COVID-19 through real-time polymerase chain reaction (RT-PCR), from Pelotas, Brazil. Self-report sequelae from COVID-19 were defined as the primary outcome. A questionnaire containing sociodemographic, medical, behavioral and self-report of sequelae of COVID-19 was applied. A complete periodontal clinical examination was performed. Weight and height were assessed. Uni-, bi- and multivariate analyses were performed using Poisson regression with robust variance. Additional analyses were performed considering obesity as a subgroup.

RESULTS

When considering the whole sample, no statistically significant associations between sequelae of COVID-19 with periodontitis (prevalence ratio [PR]:1.14;95% confidence interval [95%CI]: 0.80-1.61) and obesity (0.93 [0.68-1.26]) were identified. In the subgroup analysis, considering only individuals with obesity, those diagnosed with generalized periodontitis had 86% higher probability to have sequelae of COVID-19 when compared to individuals with periodontal health or localized periodontitis. However, when only those without obesity were considered, no significant association with periodontal status was detected (0.82 [0.55-1.23). No significant association with periodontal status were observed when the severity of sequelae (no sequelae, 1 sequela, and >1 sequela) were considered (p > 0.05).

CONCLUSIONS

Individuals diagnosed with obesity and periodontitis have a higher PR of reporting sequelae from COVID-19 compared to individuals with only obesity.

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.

Applicability of an active matrix metalloproteinase-8 point-of-care test in an oral and maxillofacial surgery clinic: a pilot study

OBJECTIVES

Matrix metalloproteinases are enzymes that participate in numerous inflammatory responses and have been targeted as biomarkers in numerous pathologic states. The detection of active matrix metalloproteinase-8 (aMMP-8) using a mouthrinse point-of-care test (POCT) has emerged as a diagnostic marker for periodontitis and other systemic inflammatory states. The objective of this pilot study was to assess the applicability of aMMP-8 POCT in an oral and maxillofacial surgery clinic and to evaluate the relationship between aMMP-8 levels and different patient groups.

MATERIALS AND METHODS

aMMP-8 POCT samples were collected from patients in an oral and maxillofacial surgery clinic during a one-month period. aMMP-8 levels were analyzed using a chairside lateral-flow immunotest and a digital reader. Clinically relevant patient variables were collected and descriptively evaluated. aMMP-8 levels over 20 ng/ml were considered to be elevated.

RESULTS

A total of 115 patients were interviewed of which 112 agreed to the test (97.4%). Elevated aMMP-8 levels were observed in 58 (51.8%) patients. Bone loss was noted in 75 (67.0%) patients. Of these patients, aMMP-8 levels were elevated in 47 (62.7%) patients. Patients at an increased risk of infection had 35.5% higher aMMP-8 values on average compared to patients with no prior illnesses.

CONCLUSION

aMMP-8 POCT provides a non-invasive and reliable method for measuring aMMP-8 levels. Future studies are warranted to assess the clinical relevance between elevated aMMP-8 levels and specific patient groups.

CLINICAL RELEVANCE

The rapid availability of the test score allows an immediate impact on treatment planning.

Identifying Oxidative Stress-Related Genes (OSRGs) as Potential Target for Treating Periodontitis Based on Bioinformatics Analysis

BACKGROUND

Periodontitis (PD) is a multifactorial inflammatory disease that is closely associated with periodontopathic bacteria. Numerous studies have demonstrated oxidative stress (OS) contributes to inflammation and is a prime factor in the development of PD. It is imperative to explore the function of newly discovered hub genes associated with OS in the advancement of PD, thereby identifying potential targets for therapeutic intervention.

OBJECTIVES

The goal of the current study was to identify the oxidative-stress-related genes (OSRGs) associated with periodontitis (PD) development using an integrated bioinformatics method.

METHODS

DEGs from GEO gene-expression data were identified using the "limma" package. We obtained OSRGs from GeneCards and utilized a Venn diagram to uncover differentially expressed OSRGs (DEOSRGs). After receiving the DEOSRGs, we employed Gene Ontology (GO), Kyoto Encyclopaedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) analytical tools to examine their possible functions and pathways in PD. Receiver operating characteristic (ROC) curves screened for hub genes of PD. RT-qPCR and western blot analysis were used to detect DEOSRG expression in mouse ligature-induced periodontitis gingival tissues.

RESULTS

The investigation identified 273 OSRGs. Based on PPI analysis, we recognized 20 OSRGs as hub genes. GO and KEGG enrichment analysis indicated that these hub genes were predominantly enriched in leukocyte migration, lymphocyte proliferation, and humoral immune response, and associated with leukocyte trans-endothelial migration, cytokine-cytokine receptor interaction, and NF-κB signaling pathway. Following ROC analysis, VCAM1, ITGAM, FCGR3A, IL1A, PECAM1, and VCAM1were identified as PD prognostic gene. RT-qPCR and western blot analyses confirmed that the expression ITGAM, FCGR3A, and PECAM1 were significantly elevated in the gingival tissues obtained from mice.

CONCLUSION

This investigation revealed that ITGAM, FCGR3A, and PECAM1 may have a crucial function in the advancement of PD.

Association between periodontal diseases and COVID-19 infection: a case-control study with a longitudinal arm

Some studies have suggested potential relationships between periodontal disease and COVID-19, explained by many possible pathological pathways. The aim of this case-control study with a longitudinal arm was to investigate this association. 80 systemically healthy individuals (apart from COVID-19) were involved in this study, divided into 40 patients who had recently had COVID-19 (test, divided into severe and mild/moderate cases) and 40 who had not had COVID-19 (control). Clinical periodontal parameters and laboratory data were recorded. Mann-Whitney U test, Wilcoxon test, and chi-square test were performed to compare variables. Multiple binary logistic regression method was used to estimate adjusted ORs and 95% confidence interval. Hs-CRP-1 and 2, Ferritin-1 and 2, lymphocyte count-1 values, and neutrophil/lymphocyte ratio-1 were higher in patients with severe COVID-19 than patients with mild/moderate COVID-19 (p < 0.05). All of these laboratory values significantly decreased after COVID-19 treatment (p < 0.05) in the test group. Presence of periodontitis (p = 0.015) was higher and periodontal health was lower (p = 0.002) in the test group than in the control group. All clinical periodontal parameters were significantly higher in the test group than in the control group (p < 0.05), except plaque index. Prevalence of periodontitis was associated with increased odds of having COVID-19 infection (PR = 1.34; 95% CI 0.23-2.45) in the multiple binary logistic regression. COVID-19 is associated with periodontitis prevalence, through a series of possible mechanisms including local and systemic inflammatory responses. Further studies should investigate whether the maintenance of periodontal health may be a factor in the reduction of the severity of COVID-19 infections.

Periodontal disease and COVID-19: Prognosis and potential pathways of association in their pathogenesis

Objective

The objective of this narrative review is to determine if periodontal disease is a factor in the development of a poor prognosis for COVID-19.

Method

A bibliographic search was conducted in PubMed, Virtual Health Library, Google Scholar, and in the databases of Science Direct, Scopus, Lilacs, Bireme, Scielo, and Web of Science, using the following keywords: "COVID-19," "SARS-CoV-2," and "periodontal diseases."

Results

Fifty-six records were retrieved from the database searches. After screening, 39 articles were selected for study: 13 reviews, 2 case-control studies, 1 systematic review, 8 letters to the editor, 2 cohort studies, 1 thesis, 7 hypotheses, 1 short communication, 3 commentaries, and 1 scoping review.

Discussion

Both periodontal disease and COVID-19 produce an inflammatory response. This immune response generates an over-production of inflammatory cytokines that can harm overall health.

Conclusion

The mouth serves as the entryway for many microorganisms that can harm health in general, among them SARS-CoV-2. It is important to maintain good oral health to lower the inflammatory load present in periodontal disease, lessening the possibility of complications from COVID-19.

Potential Roles of Selectins in Periodontal Diseases and Associated Systemic Diseases: Could They Be Targets for Immunotherapy?

Periodontal diseases are predisposing factors to the development of many systemic disorders, which is often initiated via leukocyte infiltration and vascular inflammation. These diseases could significantly affect human health and quality of life. Hence, it is vital to explore effective therapies to prevent disease progression. Periodontitis, which is characterized by gingival bleeding, disruption of the gingival capillary's integrity, and irreversible destruction of the periodontal supporting bone, appears to be caused by overexpression of selectins in periodontal tissues. Selectins (P-, L-, and E-selectins) are vital members of adhesion molecules regulating inflammatory and immune responses. They are mainly located in platelets, leukocytes, and endothelial cells. Furthermore, selectins are involved in the immunopathogenesis of vascular inflammatory diseases, such as cardiovascular disease, diabetes, cancers, and so on, by mediating leukocyte recruitment, platelet activation, and alteration of endothelial barrier permeability. Therefore, selectins could be new immunotherapeutic targets for periodontal disorders and their associated systemic diseases since they play a crucial role in immune regulation and endothelium dysfunction. However, the research on selectins and their association with periodontal and systemic diseases remains limited. This review aims to discuss the critical roles of selectins in periodontitis and associated systemic disorders and highlights the potential of selectins as therapeutic targets.

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

Objectives

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

Subjects, Materials, and Methods

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

Results

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

Conclusions

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

Pathogenic Connections in Post-COVID Conditions: What Do We Know in the Large Unknown? A Narrative Review

The coronavirus 2019 (COVID-19) disease has long-term effects, known as post-COVID conditions (PCC) or long-COVID. Post-COVID-19 syndrome is defined by signs and symptoms that occur during or after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection which persist for more than 12 weeks and cannot be supported by an alternative diagnosis. The cardiovascular damage caused by COVID-19 in the severe forms of the disease is induced by severe systemic inflammation, considered to be one of the causes of myocardial lesions, with increased levels of circulating cytokines and toxic response mediators. We have focused on conditions that can induce long-COVID-19, or multisystem inflammatory syndrome in adults or children (MIS-C/MIS-A), with an emphasis on endocrinological and metabolic disorders. Although described less frequently in children than in adults, long-COVID syndrome should not be confused with MIS-C, which is an acute condition characterized by multisystem involvement and paraclinical evidence of inflammation in a pediatric patient who tested positive for SARS-CoV-2. At the same time, we mention that the MIS-A symptoms remit within a few weeks, while the duration of long-COVID is measured in months. Long-COVID syndrome, along with its complications, MIS-A and MIS-C, represents an important challenge in the medical community. Underlying comorbidities can expose both COVID-19 adult and pediatric patients to a higher risk of negative outcomes not only during, but in the aftermath of the SARS-CoV-2 infection as well.

Is There a Link between COVID-19 and Periodontal Disease? A Narrative Review

The coronavirus disease 2019 (COVID-19) pandemic greatly affected human well-being, social behavior, global economy, and healthcare systems. Everyday clinical practice in dentistry has been adjusted to the increased hazards of aerosol production by routine dental procedures. The objective of this study was to assess the existing literature to determine possible mechanisms of a relationship between COVID-19 and periodontitis, as well as describe findings from relevant epidemiological studies.Scarce data exist in the literature that directly addresses the relationship between the two diseases. However, several data describe the role of the oral cavity and periodontal tissues as portals of entry of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), and the contribution of cytokines known to be produced in periodontal disease to severe forms of COVID-19. It is also suggested from the current literature that periodontal disease, shown to be associated with systemic diseases such as diabetes mellitus, cardiovascular and respiratory diseases, shares common risk factors with-especially-severe forms of COVID-19.Further clinical studies are required to establish the relationship between these diseases. Oral hygiene performance and intact periodontal tissues can assist in mitigating the pandemic, and it is suggested that dental practitioners can contribute to identifying at-risk patients.

aMMP-8 Oral Fluid PoC Test in Relation to Oral and Systemic Diseases

The manuscript uses the previously published literature and highlights the benefits of active-matrix metalloproteinase (aMMP)-8 chairside/point-of-care (PoC) diagnostic tools as adjunctive measures in oral and systemic diseases. Previous studies suggest that as a biomarker, aMMP-8 is more precise than total MMP-8, MMP-9, MMP-2, MMP-3, MMP-13, MMP-7, MMP-1, calprotectin, myeloperoxidase (MPO), human neutrophil elastase (HNE), tissue inhibitor of matrix metalloproteinase (TIMP)-1, and bleeding of probing (BOP). Therefore, aMMP-8 could be implemented as the needed key biomarker for the new disease classification for both periodontitis and peri-implantitis. With a sensitivity to the tune of 75-85% and specificity in the range of 80-90%, lateral flow aMMP-8 PoC testing is comparable to catalytic protease activity assays for aMMP-8. The test can be further applied to estimate the glycemic status of an individual, to ascertain whether a person is at risk for COVID-19, in managing the oral side effects of radiotherapy carried in head and neck cancers, and in selected cases pertaining to reproductive health. In the future, aMMP-8 could find application as a potential systemic biomarker in diseases affecting the cardiovascular system, cancers, bacteremia, sepsis, diabetes, obesity, meningitis, as well as pancreatitis. The aMMP-8 PoCT is the first practical test in the emerging new dental clinical field, that is, oral clinical chemistry representing oral medicine, clinical chemistry, peri-implantology, and periodontology.

Periodontitis and coronavirus disease 2019

The coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 is usually a mild condition; however, in some cases it can result in severe sickness and even death. Thus, understanding the reasons behind these grave outcomes is of great importance. Coronavirus disease 2019 and periodontitis share some intriguing characteristics. They can both lead to systemic inflammation and alterations of coagulation pathways, and both share confounding factors, such as diabetes, hypertension, and obesity. Accordingly, a possible association between these conditions has been hypothesized in the literature. The objective of this review was to evaluate the scientific evidence linking these diseases and the possible underlying mechanisms. Evidence has shown that coronavirus disease 2019 presents oral manifestations and can even affect periodontal tissues. Moreover, some studies have shown a possible association between coronavirus disease 2019 severity and the presence of periodontitis. Current evidence suggests that this association could be explained through the direct role of periodontal bacteria in aggravating lung infections, as well as through the indirect effect of periodontitis in inducing systemic inflammation and priming of the immune system to an exacerbated reaction to severe acute respiratory syndrome coronavirus 2 infection. Future research is needed to confirm these observations and explore the possible role that periodontal care might play in the coronavirus disease 2019 pandemic.

Molecular Research on Oral Diseases and Related Biomaterials: A Journey from Oral Cell Models to Advanced Regenerative Perspectives

Oral diseases such as gingivitis, periodontitis, and oral cancer affect millions of people worldwide. Much research has been conducted to understand the pathogenetic mechanisms of these diseases and translate this knowledge into therapeutics. This review aims to take the reader on a journey from the initial molecular discoveries to complex regenerative issues in oral medicine. For this, a semi-systematic literature search was carried out in Medline and Web of Science databases to retrieve the primary literature describing oral cell models and biomaterial applications in oral regenerative medicine. First, an in vitro cell model of gingival keratinocytes is discussed, which illustrates patho- and physiologic principles in the context of oral epithelial homeostasis and carcinogenesis and represents a cellular tool to understand biomaterial-based approaches for periodontal tissue regeneration. Consequently, a layered gradient nonwoven (LGN) is described, which demonstrates that the key features of biomaterials serve as candidates for oral tissue regeneration. LGN supports proper tissue formation and obeys the important principles for molecular mechanotransduction. Furthermore, current biomaterial-based tissue regeneration trends, including polymer modifications, cell-based treatments, antimicrobial peptides and optogenetics, are introduced to represent the full spectrum of current approaches to oral disease mitigation and prevention. Altogether, this review is a foray through established and new concepts in oral regenerative medicine and illustrates the process of knowledge translation from basic molecular and cell biological research to future clinical applications.

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

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

Impact of COVID-19 on Periodontitis and Peri-Implantitis: A Narrative Review

COVID-19 is reported as one of the most widespread diseases in the world. An extraordinary number of articles and manuscripts have focused on the inflammatory cascade and sequelae, showing the important roles of cytokines and renin-angiotensin levels and possible links to other pathologies. Nowadays, interest regarding the possible correlation between COVID-19 and periodontal and Peri-implant diseases is increasing. This mini-review aims to collect data regarding the possible correlation between COVID-19 and periodontitis or Peri-implantitis through the analysis of articles published in the last 3 years. The following keywords were used: ([periodontitis OR periodontal disease] AND [COVID-19]); ([Peri-implantitis OR mucositis] AND [COVID-19 OR Sars-CoV-2]). The inclusion criteria were studies on COVID-19 or SARS-CoV-2 and periodontitis or Peri-implantitis, and studies on the molecular and cellular aspect of COVID-19 in periodontal or Peri-implant tissues. The search revealed 484 articles in total (PubMed 208 and Scopus 276). After a screening of titles and abstracts, 47 articles were included in the full-text analysis. Two articles comprised the Peri-implant group: a short communication and a review. Regarding the periodontal group, 45 articles were selected and analyzed according to the type of study, population, and aim. Of these, 10 articles were clinical studies, and the other 35 were hypotheses, reviews, letters to the editor, or commentaries. In conclusion, according to the data extracted, a mutual correlation between COVID-19 and periodontitis can be stated; however, data linked to Peri-implantitis are still missing, and future clinical studies are still needed.

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

Objective

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

Background

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

Methods

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

Results

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

Conclusions

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

Active matrix metalloproteinase-8: A potential biomarker of oral systemic link

OBJECTIVES

This mini review aims to address some possible gaps in periodontal diagnosis in clinical studies particularly involving the oral-systemic connection with a view to minimize such gaps, and thus improve patient treatment experiences and outcomes.

METHODS

The conventional assessment of periodontitis has traditionally been by clinical and radiographic oral parameters. We reviewed numerous studies published mainly within the past decade, to affirm the oral-systemic link, the contribution of periodontitis to the inflammatory burden in various systemic diseases and conditions, and the potential role of active matrix metalloproteinase-8 (aMMP-8).

RESULTS

While it is established that periodontal pathogens in dental plaque biofilm are the primary initiating agents in periodontitis, it has become clear from the appraisal of recent studies that the host inflammation, including biomarkers such as aMMP-8 play a major role, being the driving underlying pathological mechanism in both periodontitis and systemic diseases.

CONCLUSIONS

The apparent limitations of conventional diagnostic tools have led researchers to seek alternative methods of evaluation such as the quantification of biomarkers including aMMP-8, which can be a bridge between oral/periodontal and systemic diseases; aMMP-8 can form a mouth-body connection.

Periodontal Diseases and COVID-19: A Scoping Review

The aim of this scoping review was to present the existing literature regarding the relationship between periodontal diseases and coronavirus disease 2019 (COVID-19). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping review guidelines was followed. Articles were retrieved from PubMed/MEDLINE and Scopus databases and screened to include studies relating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or COVID-19 to periodontal cells and/or tissues and/or diseases. Twenty-five papers were included; consisting of six reviews, seven original articles, six short reports, four letters to the editor, one commentary, and one case report. The articles were allocated to three different topics: (i) hypotheses on the relationship between periodontal diseases and COVID-19; (ii) risk factors and comorbidities common to periodontitis and COVID-19; (iii) periodontal manifestations of COVID-19. Certain molecules (angiotensin-converting enzyme-2, furin, cathepsin, TMPRSS2...) that are found at a high level in periodontal tissues, particularly in patients with periodontitis, are involved in the mechanism of entry of SARS-CoV-2 into cells. Periodontopathic bacteria could also play a direct role in the mechanism of entry of SARS-CoV-2 by cleaving the S-protein, and the cytokines produced during periodontitis could add to the cytokine storm found in the severe forms of COVID-19. It thus appears that the treatment of periodontitis, which allows a reduction in periodontopathic bacteria and of the local and systemic inflammation state, could be part of a strategy to prevent the development of severe forms of COVID-19.

The clinical association between Periodontitis and COVID-19

OBJECTIVES

The study aimed to clinically assess the association between periodontitis and COVID-19-related outcomes.

MATERIAL AND METHODS

Data pertaining to patient demographics, medical history, blood parameters, periodontal clinical examination and aMMP-8 point-of-care diagnostics (both site-level and patient-level) was recorded for eighty-two COVID-19-positive patients. COVID-19-related outcomes such as COVID-19 pneumonia, death/survival, types of hospital admission and need of assisted ventilation were also assessed.

RESULTS

Males were predominantly afflicted with COVID-19, with advanced age exhibiting a greater association with the presence of periodontitis. Higher severity of periodontitis led to 7.45 odds of requiring assisted ventilation, 36.52 odds of hospital admission, 14.58 odds of being deceased and 4.42 odds of COVID-19-related pneumonia. The aMMP-8 mouthrinse kit was slightly more sensitive but less specific than aMMP-8 site-specific tests.

CONCLUSIONS

Based on the findings of the present study, periodontitis seems to be related to poorer COVID-19-related outcomes. However, within the constraints of this work, a direct causality may not be established. Periodontitis, by means of skewing the systemic condition for a number of comorbidities, may eventually influence COVID-19 outcomes in an indirect manner.

CLINICAL RELEVANCE

The study is the first to clinically, and by means of a validated point-of-care diagnostic methodology, assess the association between periodontal health and COVID-19-related outcomes. Assessment of the periodontal status of individuals can aid in the identification of risk groups during the pandemic along with reinforcing the need to maintain oral hygiene and seeking periodontal care.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Diabetes and Oral Health: Summary of Current Scientific Evidence for Why Transdisciplinary Collaboration Is Needed

This Perspective provides a brief summary of the scientific evidence for the often two-way links between hyperglycemia, including manifest diabetes mellitus (DM), and oral health. It delivers in a nutshell examples of current scientific evidence for the following oral manifestations of hyperglycemia, along with any available evidence for effect in the opposite direction: periodontal diseases, caries/periapical periodontitis, tooth loss, peri-implantitis, dry mouth (xerostomia/hyposalivation), dysbiosis in the oral microbiome, candidiasis, taste disturbances, burning mouth syndrome, cancer, traumatic ulcers, infections of oral wounds, delayed wound healing, melanin pigmentation, fissured tongue, benign migratory glossitis (geographic tongue), temporomandibular disorders, and osteonecrosis of the jaw. Evidence for effects on quality of life will also be reported. This condensed overview delivers the rationale and sets the stage for the urgent need for delivery of oral and general health care in patient-centered transdisciplinary collaboration for early detection and management of both hyperglycemia and oral diseases to improve quality of life.

COVID-19 and periodontitis: reflecting on a possible association

Recent studies have demonstrated a relationship between the severe clinical course of COVID-19 and other chronic diseases such as: cardiovascular disease, hypertension, diabetes mellitus, obesity and chronic renal disease. It may be possible to extend this association to a common and chronic oral disease in adults: periodontitis. Alternatively, the latter could be simply related to the systemic chronic diseases cited above, as already observed in the non-COVID-19 literature. In order to provide an overview and their opinion, the authors in this perspective article will report and discuss the most recent references of interest relating to COVID-19 and periodontitis pathophysiology. Within such a narrative review, the authors will hypothesize that the association between chronic periodontitis and COVID-19 could exist via two pathways: a direct link, through the ACEII and CD147 receptors used by the virus to infect the cells, which would occur in greater numbers in cases of periodontitis (thereby favoring a SARS-CoV-2 infection); and/or an indirect pathway involving the overexpression of inflammatory molecules, especially IL-6 and IL-17. An expression of the latter has been found to play a role in periodontitis, in addition to severe cases of COVID-19, although it is still unclear if it plays a direct role in the worsening of the clinical course.

Active matrix metalloproteinase-8 and interleukin-6 detect periodontal degeneration caused by radiotherapy of head and neck cancer: a pilot study

Background: This cohort study investigated the role of the active matrix metalloproteinase-8 (aMMP-8) and interleukin-6 (IL-6) as oral fluid biomarkers for monitoring the periodontal degeneration occurring in head and neck cancer (HNC) patients treated by radiotherapy. Research design and methods: Eleven patients, aged 28-74, diagnosed with HNC were included in the study. Complete periodontal and oral examinations were performed pre-radiotherapy and 1 month after radiotherapy. Mouthrinse samples (pre-radiotherapy, after 6 weeks of radiotherapy and 1 month after radiotherapy) were assayed by aMMP-8 point-of-care-kit (PerioSafe®/ORALyzer®) for aMMP-8 and ELISA for IL-6. Results: HNC radiotherapy had a deteriorating impact on the periodontium and a significant impact on periodontal biomarkers aMMP-8 and IL-6 and increased their levels in mouthrinse. Clinical-attachment-loss (CAL) (site of greatest loss: mean = 1.7 mm, range = 1-3 mm) corresponding to rapid progression of periodontitis. There was a positive repeated measures correlation (rmcorr = 0.667) between the aMMP-8 and IL-6 levels. Conclusions: Elevated aMMP-8 levels were observed 1 month after radiotherapy among some HNC patients suggesting a prolonged increased susceptibility to further periodontal tissue destruction. Currently available aMMP-8 point-of-care testing could be useful to monitor and assess quantitatively online and real-time the risk of deterioration of periodontal health during HNC radiotherapy.