The clinical association between Periodontitis and COVID-19

Advances in the relationship between periodontopathogens and respiratory diseases (Review)

Periodontitis is a common chronic inflammatory and destructive disease in the mouth and is considered to be associated with systemic diseases. Accumulating evidence has suggested that periodontitis is a risk factor for pulmonary diseases such as pneumonia, chronic obstructive pulmonary disease (COPD), asthma, coronavirus disease 2019 (COVID‑19) and lung cancer. The presence of common periodontal pathogens has been detected in samples from a variety of pulmonary diseases. Periodontal pathogens can be involved in lung diseases by promoting the adhesion and invasion of respiratory pathogens, regulating the apoptosis of respiratory epithelium and inducing overexpression of mucin and disrupting the balance of immune systemin respiratory epithelium cells. Additionally, measures to control plaque and maintain the health of periodontal tissue can decrease the incidence of respiratory adverse events. This evidence suggests a close association between periodontitis and pulmonary diseases. The present study aimed to review the clinical association between periodontitis and pneumonia, COPD, asthma, COVID‑19 and lung cancer, and propose a possible mechanism and potential role of periodontal pathogens in linking periodontal disease and lung disease. This could provide a direction for further research on the association between periodontitis and lung disease and provide novel ideas for the clinical diagnosis and treatment management of these two diseases.

The role of viruses in oral mucosal lesions

The mucosa of the oral cavity is exposed to a large number of different microorganisms such as archaea, bacteria, fungi, parasites, and viruses. Among those, viruses cause specific infections, which can easily be transmitted from one person to another. The infectious route may not only include patients and their relatives but also the dental professional team. Thus, a wide knowledge regarding specific viral infections is crucial for the daily routine. Signs and symptoms of oral viral infections can be completely absent or develop into a pronounced clinical picture, so that early detection and information determine the further course of the infection and its influence on other inflammatory diseases, such as periodontitis, as well as the safety of family members and the social environment. As the clinical manifestation of viral infections may be highly variable leading to heterogenous mucosal lesions it is, in most cases, mandatory to differentiate them by specific microbiological tests in addition to clinical examination procedures. This article will give an overview of the role of viruses infecting the oral mucosa, and in addition, describe their clinical manifestation and management.

QbD-Assisted Development and Optimization of Doxycycline Hyclate- and Hydroxyapatite-Loaded Nanoparticles for Periodontal Delivery

The current research aims to develop a carrier system for the delivery of a matrix metalloproteinase (MMP) inhibitor along with a bioceramic agent to the periodontal pocket. It is proposed that the present system, if given along with a systemic antibiotic, would be a fruitful approach for periodontitis amelioration. To fulfill the aforementioned objective, a doxycycline hyclate- and hydroxyapatite-adsorbed composite was prepared by a physical adsorption method and successfully loaded inside sodium alginate-chitosan nanoparticles and optimized based on particle size and drug content. Optimized formulation was then subjected to different evaluation parameters like encapsulation efficiency, hydroxyapatite content, ζ potential, surface morphology, in vitro drug release, cell line studies, and stability studies. For the optimized formulation, particle size, polydispersity index (PDI), entrapment efficiency, ζ potential, and drug content were found to be 336.50 nm, 0.23, 41.77%, -13.85 mV, and 14.00%, respectively. The surface morphology of the placebo and adsorbed composite-loaded nanoparticles as observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the spherical shape and rough surface of the particles. In gingival crevicular fluid (GCF) 7.6, a sustained drug release profile was obtained up to 36 h. In vitro % viability studies performed on murine fibroblast cells (NIH3T3) and human periodontal ligament (hPDL) cell lines confirmed the proliferative nature of the formulation. Also, when subjected to stability studies for 4 weeks, particle size, PDI, and drug content did not vary considerably, thereby ensuring the stable nature of nanoparticles. Henceforth, sodium alginate-chitosan nanoparticles appeared to be a good carrier system for doxycycline hyclate and hydroxyapatite for periodontal therapy. If given along with a system antibiotic, the system will serve as a fruitful tool for infection-mediated periodontal regeneration and healing.

COVID-19 Severity in Patients With Apical Periodontitis: A Case Control Study

OBJECTIVES

Apical periodontitis (AP) has been associated with systemic inflammatory biomarkers that have also been associated with COVID-19 severity. This study was designed to test the hypothesis that the presence of apical periodontitis could be associated with increased risk of COVID-19 complications.

METHODS

A case control study (N = 949) was performed using the medical and dental records of patients diagnosed with COVID-19 in the State of Qatar between March 2020 and February 2021. Cases comprised COVID-19 patients (n = 63) who experienced complications (death, intensive care unit admissions, mechanical ventilation), and controls were COVID-19 patients (n = 886) who recovered without such complications. The presence of periapical apical periodontitis was assessed on the radiographic records taken prior to COVID-19 infection. Associations between apical periodontitis and COVID 19 complications were analysed using logistic regression models adjusted for demographic and medical factors. Blood biomarkers were assessed in both groups and compared using the Kruskal-Wallis test.

RESULTS

COVID-19 complications were found to be associated with the presence of apical periodontitis (adjusted odds ratio = 2.72; 95% CI, 1.30-5.68; P = .008). Blood analyses revealed that COVID-19 patients with apical periodontitis had higher levels of white blood cells and haemoglobin A1c than the patients without apical periodontitis.

CONCLUSIONS

The presence of apical periodontitis could be associated with increased risk of COVID-19 complications.

Clinical, immunological, and microbiological analysis of the association between periodontitis and COVID-19: a case-control study

PURPOSE

Periodontitis and coronavirus disease (COVID-19) share risk factors and activate similar immunopathological pathways, intensifying systemic inflammation. This study investigated the clinical, immunological and microbiological parameters in individuals with COVID-19 and controls, exploring whether periodontitis-driven inflammation contributes to worsening COVID-19 endpoints.

METHODS

Case (positive RT-PCR for SARS-CoV-2) and control (negative RT-PCR) individuals underwent clinical and periodontal assessments. Salivary levels of TNF-α, IL-6, IL-1β, IL-10, OPG, RANKL, neutrophil extracellular traps, and subgingival biofilm were analyzed at two timepoints. Data on COVID-19-related outcomes and comorbidity information were evaluated from medical records.

RESULTS

Ninety-nine cases of COVID-19 and 182 controls were included for analysis. Periodontitis was associated with more hospitalization (p = 0.009), more days in the intensive care unit (ICU) (p = 0.042), admission to the semi-ICU (p = 0.047), and greater need for oxygen therapy (p = 0.042). After adjustment for confounders, periodontitis resulted in a 1.13-fold increase in the chance of hospitalization. Salivary IL-6 levels (p = 0.010) were increased in individuals with COVID-19 and periodontitis. Periodontitis was associated with increased RANKL and IL-1β after COVID-19. No significant changes were observed in the bacterial loads of the periodontopathogens Porphyromona gingivalis, Aggregatibacter actinomycetemcomitans, Tanerella forsythia, and Treponema denticola.

CONCLUSIONS

Periodontitis was associated with worse COVID-19 outcomes, suggesting the relevance of periodontal care to reduce the burden of overall inflammation. Understanding the crosstalk between SARS-CoV-2 infection and chronic conditions such as periodontitis that can influence disease outcome is important to potentially prevent complications of COVID-19.

Unvaccinated periodontal patients with a history of COVID-19: clinical findings in a Dental School setting

This study analyzed the periodontal clinical data of individuals with a history of COVID-19 treated in a dental school during the pandemic in 2021 before vaccination.

METHODS

This analysis included individuals older than 18 years with no history of systemic disorders other than systemic arterial hypertension. Individuals who had COVID-19 were classified according to the World Health Organization as asymptomatic, with mild, moderate, severe, or critical symptoms.

RESULTS

A total of 95 individuals were evaluated, which included 24 with a history of COVID-19. Seventeen percent had been asymptomatic, 21% had mild, 25% moderate, 21% severe, and 17% critical symptoms, including intubation. Individuals with no history of COVID-19 presented significantly lower measurements of probing depth (p=0.003; Mann-Whitney test) and clinical attachment level (p=0.002) compared to individuals with a history of COVID-19. A significant negative association was found between bleeding on probing and the severity of characteristics of COVID-19 (rho= -0.233; p=0.023). Conversely, positive associations between the values of probing depth (rho= 0.292; p=0.004) and mean clinical attachment level (rho= 0.300; p=0.003) and the characteristics of COVID-19 were found.

CONCLUSIONS

The periodontal data shows that patients who had COVID-19 before vaccination may present a worse periodontal status when compared to patients in the same clinical setting with no history of COVID-19. However, a more extensive study should confirm it with more participants.

Increased odds for COVID-19 infection among individuals with periodontal disease

OBJECTIVES

Periodontal disease has been linked to multiple systemic conditions, but the relationship with COVID-19 still needs to be elucidated. We hypothesized that periodontal disease may be associated with COVID-19 infection.

MATERIALS AND METHODS

This study utilized cross-sectional data to establish the strength of the association between periodontal disease and COVID-19 infection. The University of Florida Health Center's i2b2 patient's registry was used to generate patient counts through ICD-10 diagnostic codes. Univariate descriptive statistics of the patient population and logistic regression to estimate odds ratios of associations between periodontal disease and COVID-19 infection were used for analysis.

RESULTS

Patients with periodontal disease were 4.4 times more likely to be positively diagnosed with COVID-19 than patients without PD. Associations remained similar and robust (P value < 0.0001) after adjustment for age (OR = 4.34; 95% CI, 3.68-5.09), gender (OR = 4.46; 95% CI, 3.79-5.23), and smoking status (OR = 4.77; 95% CI, 4.04-5.59). Associations were smaller but remained robust (P value < 0.0001) after adjusting for race (OR = 2.83; 95% CI, 2.40-3.32), obesity (OR = 2.53; 95% CI, 2.14-2.98), diabetes (OR = 3.32; 95% CI, 2.81-3.90), and cardiovascular disease (OR = 2.68; 95% CI, 2.27-3.14).

CONCLUSIONS

Periodontal disease is significantly associated with increased odds for COVID-19 infection.

CLINICAL RELEVANCE

With the caveat of a cross-sectional study design, these results suggest that periodontal disease may increase the odds for COVID-19 infection.

The impact of periodontal disease on the clinical outcomes of COVID-19: A systematic review and meta-analysis

BACKGROUND

A possible relationship between periodontitis (PD) and COVID-19 and its adverse outcomes has been suggested. Hence, the present systematic review and meta-analysis aimed to investigate the available evidence regarding the potential association between periodontitis (PD) and COVID-19 and its adverse outcomes.

MATERIALS AND METHODS

PubMed, Scopus, Web of Science, and Google Scholar were searched for relevant studies published up to April 15th, 2023. Studies that evaluated the association between PD and COVID-19 were included. Risk of bias was evaluated by two reviewers, and meta-analyses were performed using RevMan 5.3 software.

RESULTS

A total of 22 studies involving 92,535 patients from USA, Europe, Asia, the Middle East and South America were included; of these, 12 were pooled into the meta-analysis. Most of the studies (19 studies) reported a significant association between PD and COVID-19. The pooled data found a significant association between PD and COVID-19 outcomes: more severe symptoms (OR = 6.95, P = 0.0008), ICU admissions (OR = 3.15, P = 0.0001), and mortality (OR = 1.92, P = 0.21). Additionally, compared to mild PD, severe PD was significantly associated with higher risks of severe COVID-19 outcomes: severe symptoms (P = 0.02); ICU admission (P = 0.0001); and higher mortality rates (P = 0.0001). The results also revealed 58% higher risk for COVID-19 infection in patients with PD (P = 0.00001).

CONCLUSIONS

The present findings suggest a possible association between poor periodontal health and the risk of poor COVID-19 outcomes. However, owing to the observed methodological heterogeneity across the included studies, further prospective cohort studies with standardized methodologies are warranted to further unravel the potential association between periodontal disease and COVID-19 and its adverse outcomes.

Bibliometric research on analysis of links between periodontitis and cardiovascular diseases

Background

Periodontitis (PD) and cardiovascular diseases (CVD) rank among the most prevalent pathologies worldwide, and their correlation has been a subject of prolonged investigation. Numerous studies suggest shared etiological factors; however, a definitive causal connection remains unestablished. The objective of this study was to employ bibliometric and visual analyses in order to comprehensively examine the overarching characteristics, focal areas of research, and prospective trends pertaining to the PD-CVD relationship.

Methods

We sourced articles, reviews, and online publications on PD- and CVD- research from the Web of Science Core Collection (WoSCC) spanning from January 1, 1993, to May 15, 2023. A triad of analytical tools (R-Bibliometrix, VOSviewer 1.6.19, and CiteSpace 6.2.R3) were utilized to facilitate collaboration network analysis, co-citation analysis, co-occurrence analysis, and citation burst detection.

Results

Out of the 1,116 publications that fulfilled the eligibility criteria in the WoSCC database, the comprehensive characteristics analysis divulged a sustained growth trend in publication frequency. In the cluster analysis of reference co-citation and keyword co-occurrence, prominent themes such as "periodontitis", "cardiovascular diseases", "inflammation", "Porphyromonas gingivalis", and "atherosclerosis" consistently emerged. Contemporary topics such as "peri-implantitis," "COVID-19", "cardiovascular risk factors," and "endocarditis" were pinpointed as burgeoning research hotspots.

Conclusion

Based on this bibliometric study, in the field of association studies between PD and CVD, the etiologic mechanisms of both diseases have been intensively studied in the last three decades. Periodontal pathogens might serve as potential initiating factors linking PD and CVD. Inflammation may constitute a significant etiological factor shared by both diseases. Several emerging topics, such as COVID-19 and peri-implantitis, exhibit promising potential. This exhaustive overview casts light on pivotal research arenas, augmenting the field's understanding and stimulating further scholarly investigations.

Prevalence of oral complications in the course of severe SARS-CoV-2 infection under mechanical non-invasive ventilation

BACKGROUND

The management of oral health during severe symptoms of Covid-19 is still a challenge, especially in intensive care units under invasive/noninvasive ventilation in hospital. Understanding the cause-and-effect relationships may allow for individual adjustment of oral care recommendations during Covid-19 disease. The study's objective was to assess Covid-19 patients' oral health status under hospital treatment due to pulmonary adverse Covid-19 outcomes.

MATERIAL AND METHODS

Covid-19 patients (mean age 74.4 ± 15.4; n = 120, male n = 50/female n = 70) were admitted to hospital in the acute phase of Covid-19 between January and March 2022 who required oxygen therapy due to pneumonia, rapid respiratory failure, low saturation. Blood and radiological tests were taken according to National Health Fund guidelines. The condition of teeth (Decayed, Missing, Filled teeth as DMFT index), dental hygiene (Plaque Control Record as PCR index), periodontal status (probing depth PD, clinical attachment CAL, bleeding on probing BOP) and oral mucosa (BRUSHED and Beck scores) were examined.

RESULTS

Charateristics of the teeth (dental caries 35.2%, DMFT Median 22), plaque retention (83.4%), advanced periodontitis (48.3%), xerostomia (74.2%), oral mucosa inflammation (80.8%), angular cheilitis (53.3%), hemorrhagic (21.7%) showed a high incidence of harmful oral conditions. BRUSHED model and Beck score indicated moderate oral dysfunction and need for oral care every 8 h. Spearman's analysis revealed a significant positive correlation between pneumonia and neutrophile, interleukin-6 IL-6, C-reactive protein CRP (p = 0.01, p < 0.001, p < 0.001), negative to lymphocyte count (p < 0.001). Multiple and logistic regressions selected the following risk predictors for pneumonia as IL-6, CRP, obesity and for severe COVID-19 symptoms D-dimer level and a lack of targeted vaccination (p < 0.001). Among oral predictors, the PCR index and Beck score were significant for both outcomes (respectively p < 0.001, p < 0.012). Patients who received oxygen therapy with face masks had more often angular heilitis and debris (p = 0.025, p = 0.035).

CONCLUSIONS

COVID-19 hospitalised patients with severe symptoms crossing with poor oral health-related conditions. This may exacerbate a response for COVID infection, and play a role in cytokine storm. For Covid-19 management, to inhibit extraoral/intraoral complications, it is recommended to adjust oral hygiene procedures, including antibacterial, protective, moisturising agents after individual oral health assessment.

Association between the severity of periodontitis, COVID-19, C-reactive protein and interleukin-6 levels in hospitalized patients: a case‒control study

BACKGROUND

The COVID-19 pandemic is perhaps one of the most important events of the 21st century. Periodontitis is one of the most prevalent diseases of the oral cavity. Due to possible pathways of interaction between these two diseases, we investigated their association.

METHODS

The study population consisted of hospitalized patients with established COVID-19 diagnoses. Patients with mild to moderate COVID-19 were considered controls, while cases had severe to critical COVID-19. Periodontal examination and serum and saliva sampling were performed for each patient. Relevant medical data were extracted from patients' hospital files.

RESULTS

Of the enrolled patients, 122 were included in the statistical analyses. The severity of periodontitis was directly and significantly correlated with the severity of COVID-19 (P < 0.001). Patients with generalized stage III or IV periodontitis displayed an adjusted odds ratio of 4.24 for severe to critical COVID-19. Salivary and serum interleukin-6 levels were significantly associated with COVID-19 severity (P values: 0.002 and 0.004, respectively). Hospitalization length was significantly associated with the severity of periodontitis (P = 0.004). Clinical attachment level and gingival index were associated with increased odds for adverse events (P values: 0.004 and 0.035, respectively), while number of remaining teeth was associated with decreased odds for adverse events (P = 0.023).

CONCLUSIONS

This study showed that the severity of periodontitis is associated with the severity of COVID-19. This association might manifest as increased odds of adverse events. COVID-19 severity was associated with higher levels of salivary and serum interleukin-6 levels.

Relationship between periodontitis and COVID-19: A bidirectional two-sample Mendelian randomization study

Background and Aims

Coronavirus disease (COVID-19) is a major danger to world health and has been linked to periodontitis in a number of epidemiological observational studies. However, it is unclear whether COVID-19 causes periodontitis. COVID-19's causal influence on periodontitis was determined using bidirectional Mendelian randomization (MR).

Methods

Large-scale COVID-19 and periodontitis genome wide association study data were analyzed. Inverse variance weighting, MR-Egger, weighted median, and MR-PRESSO were used to estimate causal effects. Sensitivity studies were conducted using the Cochran's Q test, the MR-Egger intercept test, the MR-PRESSO, and the leave-one-out (LOO) analysis. Further investigation of potential mediating factors was performed using risk factor analysis.

Results

The MR presented no causal relationship between periodontitis and hospitalization for COVID-19 (odds ratio [OR] = 0.97, 95% confidence interval [CI] 0.78-1.20; p = 0.76), vulnerability to COVID-19 (OR = 1.04, 95% CI 0.88-1.21; p = 0.65), COVID-19 disease severity (OR = 1.01, 95% CI 0.92-1.11; p = 0.81). Meanwhile, a noncausal effect of genetic hospitalization for COVID-19, illness severity, and vulnerability to periodontitis was detected. Other MR methods yielded identical results to inverse variance weighting. According to sensitivity analysis, horizontal pleiotropy is unlikely to affect causal estimation.

Conclusion

Periodontitis had no link to the risk of COVID-19 hospitalization, susceptibility, or severity. However, the substance in COVID-19 that is responsible for this effect must be studied further.

Hematologic tests and their association with the severity of COVID-19 and periodontitis in hospitalized patients: a case-control study

BACKGROUND

The presence of comorbidities, especially those with a chronic inflammatory nature such as periodontitis, can facilitate COVID-19 progression toward more severe forms. Both of these diseases can affect systemic health and alter hematological test results. In this study, we decided to investigate COVID-19 and periodontitis' possible interaction with these alterations.

METHODS

Hospitalized patients with a definitive diagnosis of COVID-19 were included. Controls had mild to moderate COVID-19, while cases had severe to critical COVID-19. Periodontal examination was done for each patient. Relevant medical and hematological data were extracted from patient's hospital files.

RESULTS

A total of 122 patients entered the final analysis. The minimum white blood cell counts were associated with the severity of periodontitis. The interaction between periodontitis and COVID-19 was associated with increased minimum white blood cell counts and decreased platelet counts. COVID-19 severity was associated with increased venous oxygen saturation, prothrombin time, the maximum partial thromboplastin time, the maximum and average urea, the maximum creatinine, the maximum potassium, and lactate dehydrogenase, and decreased sodium levels.

CONCLUSIONS

Results of this study showed that several blood parameters were associated with periodontitis, COVID-19, or the interaction between them.

The association between respiratory diseases and periodontitis: A systematic review and meta-analysis

AIM

To evaluate (1) whether periodontitis has an influence on the prevalence/incidence of respiratory diseases (chronic obstructive pulmonary disease [COPD], asthma, community-acquired pneumonia [CAP], obstructive sleep apnoea [OSA] and COVID-19), and (2) what is the impact of periodontal therapy on the onset or progression of respiratory diseases.

MATERIALS AND METHODS

An electronic search was performed on Pubmed, Cochrane Library and Scopus databases up to October 2021, to identify studies answering the PECOS and PICOS questions.

RESULTS

Seventy-five articles were selected. Meta-analyses identified statistically significant associations of periodontitis with COPD (nstudies  = 12, odds ratio [OR] = 1.28, 95% confidence interval [CI] [1.16; 1.42], p < .001), and OSA (ns  = 6, OR = 1.65, 95% CI [1.21; 2.25], p = .001), but not for asthma (ns  = 9, OR = 1.53, 95% CI [0.82; 2.86], p = .181). For acute conditions, two studies were found for CAP, while for COVID-19, significant associations were found for the need of assisted ventilation (ns  = 2, OR = 6.24, 95% CI [2.78; 13.99], p < .001) and COVID-related mortality (ns  = 3, OR = 2.26, 95% CI [1.36, 3.77], p = .002). Only four intervention studies were found, showing positive effects of periodontal treatment on COPD, asthma and CAP.

CONCLUSIONS

A positive association between periodontitis and COPD, OSA and COVID-19 complications has been found, while there is a lack of intervention studies.

Relationship between the Social Development Index and Self-Reported Periodontal Conditions

Inequalities in oral health are influenced by the social strata of the population. Few studies have focused on the multitude of factors related to social development as indicators of living conditions and periodontal health status. The aim of this study is to evaluate the association between self-reported periodontal conditions and the Social Development Index (SDI). A cross-sectional validated questionnaire was carried out among 1294 Mexican adults. Descriptive statistics and multivariate logistic regression models were used to identify the best predictors of self-reported periodontal conditions. Bone loss reporting was used as a proxy for the presence of periodontal disease. We found that higher global scores on the SDI and quality and available space in the home (QASH) increase the probability of having bone loss. Global SDI (OR = 7.27) and higher QASH (OR = 3.66) were indeed the leading societal factors related to periodontal disease. These results have pointed out how SDI and its indicators, in particular QASH, can be used to further explore inequities related to privileged access to dental care in the context of periodontal diseases.

Oral and systemic health: is there a "new" link with COVID-19?

OBJECTIVES

The objective of the present narrative review was to evaluate the evidence of a possible association between periodontitis and COVID-19, and its biological plausibility, using as models the potential associations with cardiovascular diseases, diabetes, and some respiratory diseases.

METHODS

A recent systematic review was used as main reference to explore the associations of periodontitis with different respiratory diseases, including COVID-19, following two focussed questions: a PECOS question, aimed to explore epidemiological evidence, and a PICOS question, designed to explore the evidence derived from intervention studies. In addition to that evidence, other relevant scientific documents, including consensus papers, were carefully selected and appraised.

FINDINGS

Convincing evidence was found to support the association of periodontitis and cardiovascular diseases, diabetes, and some respiratory diseases. The biological plausibility behind those associations is based on four factors: (1) bacteraemia of oral bacteria and periodontal pathogens, (2) increased systemic inflammation, (3) common genetic factors, and (4) common environmental risk factors. Limited initial evidence is available to support an association between periodontitis and COVID-19 complications. Among the proposed factors to explain the suggested association, a combination of the previously mentioned factors, plus additional factors related with SARS-CoV-2 characteristics and pathogenicity, has been suggested.

CONCLUSIONS

Initial evidence suggests that periodontitis may be associated with a more severe COVID-19 and with a higher risk of death due to COVID-19.

CLINICAL RELEVANCE

Due to the possible association between periodontitis and an increased severity for COVID-19, additional efforts should be made to improve oral and periodontal health, including the promotion of oral healthy habits, such as oral hygiene.

Epidemiological pattern of COVID-19 and its association with periodontal health in an urban Indian cohort

Background

Studies have highlighted a possible influence of gingival and periodontal disease (PD) on COVID-19 risk and severity. However, the evidence is based on hospital-based studies and community-level data are sparse.

Objectives

We described the epidemiological pattern of SARS-CoV-2 infection in Delhi and evaluated the associations of gingival and PD with incident COVID-19 disease in a regionally representative urban Indian population.

Methods

In a prospective study nested within the Centre for Cardiometabolic Risk Reduction in South-Asia (CARRS) study, participants with clinical gingival and periodontal status available at baseline (2014–16) (n = 1,727) were approached between October 2021 to March 2022. Information on COVID-19 incidence, testing, management, severity was collected as per the WHO case criteria along with COVID-19 vaccination status. Absolute incidence of COVID-19 disease was computed by age, sex, and oral health. Differences in rates were tested using log-rank test. Poisson regression models were used to evaluate independent associations between gingival and PD and incidence of COVID-19, adjusted for socio-demographic and behavioral factors, presence of comorbidity, and medication use.

Results

Among 1,727 participants, the mean age was 44.0 years, 45.7% were men, 84.5% participants had baseline gingival or PD and 89.4% participants had received at least one dose of COVID-19 vaccine. Overall, 35% (n = 606) participants were tested for COVID-19 and 24% (n = 146/606) tested positive. As per the WHO criteria total number of cases was 210, constituting 12% of the total population. The age and sex-specific rates of COVID-19 were higher among men and older participants, but women aged &gt;60 years had higher rates than men of same age. The incidence rate did not differ significantly between those having gingival or PD and healthy periodontium (19.1 vs. 16.5/1,000 person-years) and there was no difference in risk of COVID-19 by baseline oral disease status.

Conclusion

Gingival and PD were not associated with increased risk of COVID-19.

Periodontitis and COVID-19: Immunological Characteristics, Related Pathways, and Association

Both periodontitis and Coronavirus disease 2019 (COVID-19) pose grave threats to public health and social order, endanger human life, and place a significant financial strain on the global healthcare system. Since the COVID-19 pandemic, mounting research has revealed a link between COVID-19 and periodontitis. It is critical to comprehend the immunological mechanisms of the two illnesses as well as their immunological interaction. Much evidence showed that there are many similar inflammatory pathways between periodontitis and COVID-19, such as NF-κB pathway, NLRP3/IL-1β pathway, and IL-6 signaling pathway. Common risk factors such as gender, lifestyle, and comorbidities contribute to the severity of both diseases. Revealing the internal relationship between the two diseases is conducive to the treatment of the two diseases in an emergency period. It is also critical to maintain good oral hygiene and a positive attitude during treatment. This review covers four main areas: immunological mechanisms, common risk factors, evidence of the association between the two diseases, and possible interventions and potential targets. These will provide potential ideas for drug development and clinical treatment of the two diseases.

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.

Association between periodontitis and COVID-19 infection: a two-sample Mendelian randomization study

Background and Objective

Epidemiological studies report associations between coronavirus disease 2019 (COVID-19) and periodontitis; however, causality has not been proven. The aim of this study is to assess the associations between COVID-19 susceptibility and periodontitis with two-sample Mendelian randomization (MR) analyses.

Methods

A two-sample summary MR analysis was performed using data for outcome and exposure from the OpenGWAS database on people of European descent. Periodontal complex traits (PCTs) were chosen as a proxy for the periodontitis phenotype. The causal association between PCT3 (Aggregatibacter actinomycetemcomitans), PCT5 (Porphyromonas gingivalis), and gingival crevicular fluid (GCF) interleukin-1β (IL-1β) and COVID-19 were considered. Genome-wide association study (GWAS) data with the two largest sample sizes were selected as COVID-19 outcomes (datasets ebi-a-GCST010776 and ebi-a-GCST010777). Single-nucleotide polymorphisms (SNPs) associated with PCT3, PCT5, and GCF IL-1β at statistical significance at genome-wide level (P < 5 × 10^-8) were identified as genetic instruments. We used two-sample summary MR methods and tested the existence of a pleiotropic effect with MR-Egger.

Results

Inverse-variance weighted (IVW) estimates showed that there was a positive association between COVID-19 risk and periodontitis (ebi-a-GCST010776: odds ratio [OR] = 1.02 (95% confidence interval (CI), 1.00-1.05), P = 0.0171; ebi-a-GCST010777: OR = 1.03 (95% CI, 1.00-1.05), P = 0.0397). The weighted median also showed directionally similar estimates. Exploration of the causal associations between other PCTs and COVID-19 identified a slight effect of local inflammatory response (GCF IL-1β) on COVID-19 risk across the two datasets (ebi-a-GCST010776: IVW OR = 1.02 (95% CI, [1.01-1.03]), P < 0.001; ebi-a-GCST010777: IVW OR = 1.03 (95% CI, [1.02-1.04]), P < 0.001). The intercepts of MR-Egger yielded no proof for significant directional pleiotropy for either dataset (ebi-a-GCST010776: P = 0.7660; ebi-a-GCST010777: P = 0.6017).

Conclusions

The findings suggests that periodontitis and the higher GCF IL-1β levels is causally related to increase susceptibility of COVID-19. However, given the limitations of our study, the well-designed randomized controlled trials are needed to confirm its findings, which may represent a new non-pharmaceutical intervention for preventing COVID-19.

Associations between Periodontitis, COVID-19, and Cardiometabolic Complications: Molecular Mechanisms and Clinical Evidence

Periodontitis is a microbially driven, host-mediated disease that leads to loss of periodontal attachment and resorption of bone. It is associated with the elevation of systemic inflammatory markers and with the presence of systemic comorbidities. Coronavirus disease 2019 (COVID-19) is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although the majority of patients have mild symptoms, others experience important complications that can lead to death. After the spread of the COVID-19 pandemic, several investigations demonstrating the possible relationship between periodontitis and COVID-19 have been reported. In addition, both periodontal disease and COVID-19 seem to provoke and/or impair several cardiometabolic complications such as cardiovascular disease, type 2 diabetes, metabolic syndrome, dyslipidemia, insulin resistance, obesity, non-alcoholic fatty liver disease, and neurological and neuropsychiatric complications. Therefore, due to the increasing number of investigations focusing on the periodontitis-COVID-19 relationship and considering the severe complications that such an association might cause, this review aims to summarize all existing emerging evidence regarding the link between the periodontitis-COVID-19 axis and consequent cardiometabolic impairments.

Beneficial Effects of Melatonin on Periodontitis Management: Far More Than Oral Cavity

Periodontitis as a highly prevalent chronic infection/inflammatory disease can eventually lead to tooth loss and masticatory dysfunction. It also has a negative impact on general health and largely impairs quality of life. The tissue destruction during periodontitis is mainly caused by the excessive immune-inflammatory response; hence, how to modulate the host's reaction is of profound importance for effective periodontal treatment and tissue protection. Melatonin, as an endogenous hormone exhibiting multiple biological functions such as circadian rhythm regulation, antioxidant, and anti-inflammation, has been widely used in general healthcare. Notably, the past few years have witnessed increasing evidence for the application of melatonin as an adjunctive approach in the treatment of periodontitis and periodontitis-related systemic comorbidities. The detailed underlying mechanisms and more verification from clinical practice are still lacking, however, and further investigations are highly required. Importantly, it is essential to establish standard guidelines in the near future for the clinical administration of melatonin for periodontal health and general wellbeing.

The Role of Oral Health in the Acquisition and Severity of SARS-CoV-2: A Retrospective Chart Review

Objective

Studies have shown that gingival crevices may be a significant route for SARS-CoV-2 entry. However, the role of oral health in the acquisition and severity of COVID-19 is not known.

Design

A retrospective analysis was performed using electronic health record data from a large urban academic medical center between 12/1/2019 and 8/24/2020. A total of 387 COVID-19 positive cases were identified and matched 1:1 by age, sex, and race to 387 controls without COVID-19 diagnoses. Demographics, number of missing teeth and alveolar crestal height were determined from radiographs and medical/dental charts. In a subgroup of 107 cases and controls, we also examined the rate of change in alveolar crestal height. A conditional logistic regression model was utilized to assess association between alveolar crestal height and missing teeth with COVID-19 status and with hospitalization status among COVID-19 cases.

Results

Increased alveolar bone loss, OR = 4.302 (2.510 - 7.376), fewer missing teeth, OR = 0.897 (0.835-0.965) and lack of smoking history distinguished COVID-19 cases from controls. After adjusting for time between examinations, cases with COVID-19 had greater alveolar bone loss compared to controls (0.641 ± 0.613 mm vs 0.260 ± 0.631 mm, p < 0.01.) Among cases with COVID-19, increased number of missing teeth OR = 2.1871 (1.146- 4.174) was significantly associated with hospitalization.

Conclusions

Alveolar bone loss and missing teeth are positively associated with the acquisition and severity of COVID-19 disease, respectively.

A pilot clinical and radiographic study on the association between periodontitis and serious COVID‐19 infection

Background

During the pandemic of COVID‐19, the scientific community tried to identify the risk factors that aggravate the viral infection. Oral health and specifically periodontitis have been shown to have a significant impact on overall health. Current, yet limited, evidence suggests a link between periodontal status and severity of COVID‐19 infection.

Objectives

The present pilot study aimed to assess whether younger patients (≤60 years) that have been hospitalized in the intensive care unit (ICU) for severe COVID‐19 infection were susceptible to severe periodontitis.

Material and Methods

All dentate patients ≤60 years of age diagnosed with COVID‐19 and surviving hospitalization in the ICU were considered for inclusion. Susceptibility to periodontitis was determined by assessing radiographic bone loss (RBL) in recent dental radiographs (posterior bitewings, periapical, and panoramic X‐rays). RBL in % was obtained from the most affected tooth and patients were classified into: Stage I, RBL ≤ 15%; Stage II, RBL = 15%−33% and Stage III/IV, RBL ≥ 33%. The grade was defined using the RBL to age ratio on the most severely affected tooth. Patients were attributed to: Grade A, ratio <0.25; Grade B, ratio 0.25−1 and Grade C, ratio >1. Patients classified into Stage III/IV and Grade C were considered highly susceptible to periodontitis.

Results

Of 87 eligible patients, 30 patients were finally assessed radiographically and/or clinically; from the remaining 57 patients, 16 refused participation for various reasons and 41 could not be reached. Based on the radiographic assessment, all patients were periodontally compromised. Half of them were classified with Stage III/IV and Grade B or C; 26.7% were classified with Stage III/IV and Grade C.

Conclusions

The present pilot study showed that about half of the patients suffering from severe forms of COVID‐19 infection in need of ICU admission suffered also from severe periodontitis, and about one‐fourth of them were highly susceptible to it.

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.

Association between periodontitis and COVID-19 severity in a tertiary hospital: A retrospective cohort study

Introduction

Periodontitis is a chronic inflammatory disease caused by biofilm accumulation resulting in loss of periodontal attachment which could be linked to systemic implications. Coronavirus disease of 2019 (COVID-19) is a disease caused by SARS-CoV-2 that triggers damage to the lungs and other organs. COVID-19 and periodontitis share similar risk factors such as smoking, obesity, old age, and diabetes mellitus. Studies noted that periodontitis along with some systemic diseases has increased mortality. Thus, this study aims to examine the association of periodontitis with COVID-19 outcomes.

Methods

This observational study included periodontitis group and non-periodontitis group for COVID-19 outcome assessment. Inclusion criteria were applied to select adults (≥18 years old) who showed at least one dental visit, and were isolated or admitted due to a COVID-19 complication (i.e. in-ward, ICU, or death). Exclusion criteria were patients with no active dental records. The periodontal status was examined from posterior bitewings and panoramic radiographs. The primary outcome assessed was COVID-19 complications versus no admission.

Results and discussion

This study was the first of its kind as a retrospective cohort study to assess the association between periodontitis and COVID-19 severity in Riyadh, Saudi Arabia. Our findings revealed that periodontitis is statistically associated with COVID-19 severity. Periodontitis patients were three times more likely to have COVID-19 complications (p = 0.025). Diabetes (p = 0.004) and hypertension (p = 0.016) patients were 3.5 times more likely to have COVID-19 complications.

Conclusion

Understanding the potential association between periodontitis and COVID-19 through systemic inflammation might be a pathway to achieve high quality medical care.

Changes in the organs and tissues of the oral cavity in the new coronavirus infection (COVID-19): A review

SARS-CoV-2 infection can cause changes in the organs and tissues of the oral cavity, which is associated with a wide distribution of angiotensin-converting enzyme type 2 in the oral cavity, mainly epithelial cells of the oral mucosa, gums and fibroblasts of the periodontal ligament. Thus, the oral mucosa is susceptible to SARS-CoV-2 infection and may act as a gateway for the virus, as well as a reservoir for SARS-CoV-2. We searched the literature for the period from the beginning of the pandemic until May 30, 2022, devoted to the study of changes in the organs and tissues of the oral cavity with a new coronavirus infection (COVID-19) in the electronic search engines PubMed/MEDLINE and Scopus. A special place in the study of changes in the organs and tissues of the oral cavity with a new coronavirus infection (COVID-19) is occupied by periodontal pathology. A number of reviews and clinical studies conclude the importance of good oral hygiene and periodontal health as an important aspect of COVID-19 prevention and management. Oral probiotics can be considered as a promising direction for correcting changes in organs and tissues of the oral cavity in COVID-19.

Periodontitis and COVID-19: Biological Mechanisms and Meta-analyses of Epidemiological Evidence

Since the beginning of 2020, the entire global health care system has been severely challenged by the outbreak of coronavirus 2019 disease (COVID-19). Robust evidence has demonstrated a more severe course of COVID-19 in the presence of several comorbidities, such as cardiovascular diseases, diabetes mellitus, and obesity. Here, we critically appraise the recent research discoveries linking periodontitis to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and to severe COVID-19, with a special focus on the associated biological mechanisms and the available epidemiological evidence. SARS-CoV-2 main receptors and coreceptors (ACE2, TMPRSS2, furin, CD147) are overexpressed in periodontal tissues of periodontitis patients, with inflammation, periodontal pathogens, and damage-induced pyroptosis triggering a positive feedback loop. However, meta-analyses of epidemiological studies only indicated a nonstatistically significant tendency for an increased risk of SARS-CoV-2 infection in subjects with periodontitis (odds ratio [OR] = 1.69; 95% CI, 0.91-3.13, P = 0.09). Furthermore, periodontitis may worsen clinical COVID-19 courses through multiple direct and indirect pathways, including damage to lower airways due to aspiration of periodontal pathogens, exacerbation of the cytokine storm via the low-grade chronic systemic inflammation, and SARS-CoV-2 dissemination through the ulcerated gingival epithelium with consequent induced pulmonary vessels vasculopathy. Indeed, meta-analyses of epidemiological studies indicated that periodontitis subjects are more likely to experience a more severe course of COVID-19. Specifically, periodontitis was associated with a 4-fold increased odds of hospitalization (OR = 4.72; 95% CI, 1.11-20.03, P = 0.04), 6-fold of requiring assisted ventilation (OR = 6.24; 95% CI, 2.78-14.02, P = 0.00), and more than 7-fold of death due to COVID-19 complications (OR = 7.51; 95% CI, 2.16-26.10, P = 0.00). The breakthrough analyzed here emphasizes the relevance of the mouth-systemic connection as a target to mitigate the current COVID-19 emergency and the future predicted coronavirus pandemics.

Prevalence, Features and Degree of Association of Oral Lesions in COVID-19: A Systematic Review of Systematic Reviews

Regardless of rapidly emerging findings on oral lesions described in adult SARS-CoV-2-positive subjects, the evidence level remains quite low and rather contrasting; therefore, the present systematic review of systematic reviews primarily aims to point out the overall prevalence of diagnosed cases. Secondary aims are to estimate the degree of association between oral lesions and SARS-CoV-2 infection and to grade, based on the reported frequency, the primary oral lesions, with related clinical presentations and microscopic features, in relation to COVID-19 forms. A study protocol compliant with the PRISMA statement was developed. Twelve studies were included, reporting highly heterogeneous and incomplete findings, thus precluding a meta-analysis. Further studies should be conducted to assess the overall prevalence of cases diagnosed with oral lesions among adult SARS-CoV-2-positive subjects, especially considering novel viral variants, and to determine their degree of association with SARS-CoV-2 infection and COVID-19 forms. Moreover, the reported findings noticed the need to evaluate the putative role both of SARS-CoV-2 in oral lesions genesis and of periodontitis and periodontal microbiome in COVID-19 worsening and re-activations. Deeper insights into oral lesions in adult SARS-CoV-2-positive subjects could enhance the comprehension of illness pathogenesis, natural history and clinical presentation, thus improving the preparedness of health professionals in the inter-disciplinary management of COVID-19.

Association between Periodontitis and COVID-19 Based on Severity Scores of HRCT Chest Scans

Background: A relationship between periodontitis and COVID-19 may exist, as highlighted by several hypothetical models. However, the evidence is limited. Hence, the present study was conducted to determine whether an association exists between periodontitis and COVID-19. Methods: A cross-sectional study was carried out with patients diagnosed with COVID-19 who were divided into three groups—mild, moderate, and severe COVID-19—based on the COVID-19 severity score of high-resolution computed tomography (HRCT) chest scans. Periodontal parameters—including the plaque index (PI), ratio of sites with gingival bleeding (BOP), pocket depth (PD), gingival recession (REC), clinical attachment loss (CAL), and mean numbers of mobile and missing teeth due to periodontitis—were recorded for all three groups. Statistical analyses were applied to the data. Results: Of 294 patients with COVID-19, approximately 50.68% (n = 149) had periodontitis, and the highest percentage (87.5%) was reported in the severe COVID-19 group. Additionally, severe and advanced stages of periodontitis (stage III–IV) were found to be significantly more frequent in subjects with severe COVID-19 than in the other two groups. The HRCT severity score (CT-SS) was moderately correlated with increased levels of periodontal parameters. Conclusions: Results of logistic regression analyses showed that the probability of developing severe COVID-19 was 2.81 times higher in patients with periodontitis. An association exists between periodontitis and severe COVID-19.

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.

Poor oral health status and adverse COVID-19 outcomes: A preliminary study in hospitalized patients

BACKGROUND

Most of the common risk factors for severe outcomes of coronavirus disease 2019 (COVID-19) are correlated with poor oral health, tooth loss, and periodontitis. This has pointed to a possible relationship between oral and systemic health in COVID-19 patients. Hence, this study aimed to assess the dental and periodontal status of hospitalized COVID-19 patients and their associations with the incidence of adverse COVID-19 outcomes.

METHODS

We included 128 hospital patients aged between 20 and 97 years and with diagnoses of COVID-19 in this prospective observational study. Dental and periodontal status was assessed using in-hospital clinical examinations, including the Decayed, Missing, and Filled Teeth index, periodontal status, and tooth loss patterns (Eichner index). Associations between oral health measures, the severity of COVID-19 symptoms, and hospitalization endpoints were tested using chi-square test and incidence rate ratio (IRR) estimation using a generalized linear model with log-Poisson regression. The regression models used a block-wise selection of predictors for oral health-related variables, comorbidities, and patients' ages.

RESULTS

Overall, poor oral health conditions were highly prevalent and associated with critical COVID-19 symptoms, higher risk for admission in the intensive care unit (ICU), and death. Periodontitis was significantly associated with ICU admission (IRR = 1.44; 95% confidence interval [95%CI] = 1.07-1.95; P = 0.017), critical symptoms (IRR = 2.56; 95%CI = 1.44-4.55; P = 0.001), and risk of death (IRR = 2.05; 95%CI = 1.12-3.76; P = 0.020) when adjusted for age and comorbidities. The Eichner index (classes B and C) was associated with ICU admission.

CONCLUSION

There was a positive association between deleterious oral health-related conditions, especially periodontitis, and severe COVID-19 outcomes in hospitalized COVID-19 patients.

Does periodontitis influence the risk of COVID-19? A scoping review

Objective

Research has shown that the novel severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) significantly influences the oral microbiome to expedite systemic diseases by invading harmful oral pathogens near and distant organs. To identify, explore, and map the possible mechanisms underlying periodontitis in severe coronavirus disease 2019 (COVID‐19) cases.

Material and Methods

Relevant articles published from December 2019 to February 2022 were identified and screened using keywords and inclusion criteria from various databases.

Results

This review sheds light on multiple pathways of periodontitis, the spread of periodontal infection and microbial metabolites to the lungs, and the dysregulated immune system with elevated cytokines, reactive oxygen species generation, nuclear DNA damage, and senescence, which have the potential to promote stronger viral attachment to host cells and the onset of COVID‐19 manifestation with increased severity and risk of mortality. In addition, the cytokine connection to SARS‐CoV‐2, T‐cell responses against periodontitis, its connection with COVID‐19, the role of host factors, and periodontal therapy have been discussed.

Conclusions

The relationship between COVID‐19 and periodontitis needs further investigation along with the development of alternative therapies to prevent periodontitis for better management and control of COVID‐19.

Relationship between Recovery from COVID-19-Induced Smell Loss and General and Oral Health Factors

Background and Objectives: Loss of smell is one of the strongest predictors of coronavirus disease 2019 (COVID-19) and can persist long after other symptoms have resolved. “Long” cases (>28 days) of smell dysfunction present future challenges to medical and dental professionals, as there is a lack of evidence on the causes and any exacerbating or relieving factors. This study aimed to explore the persistence of COVID-19-induced smell loss and association with physical, lifestyle and oral health factors. Materials and Methods: This study was a cross-sectional survey of 235 participants. Recovery of smell was explored, comparing rapid recovery (≤28 days) with prolonged recovery (>28 days). Associative factors included age, sex, illness severity, diet, BMI, vitamin D supplementation, antidepressants, alcohol use, smoking, brushing frequency, flossing, missing teeth, appliances and number of dental restorations. Results: Smell loss showed 87% resolution within 30 days. Prolonged smell loss was significantly associated with older age (mean ± 95%, CI = 31.53 ± 1.36 years for rapid recovery vs. mean ± 95%, CI = 36.0 ± 3 years for prolonged recovery, p = 0.003) and increased self-reported illness severity (mean ± 95%, CI = 4.39 ± 0.27 for rapid recovery vs. 5.01 ± 0.54 for prolonged recovery, p = 0.016). Fisher’s exact test revealed flossing was associated with rapid recovery, with flossers comprising 75% of the rapid-recovery group, compared to 56% in the prolonged-recovery group (odds ratio ± 95%, CI = 2.26 (1.23–4.15), p = 0.01). All other factors were not significantly associated (p > 0.05). Conclusions: Increased age and illness severity were associated with prolonged smell recovery. Use of floss was the only modifiable factor associated with rapid recovery of smell loss. As 87% of cases resolve within 30 days, future studies may benefit from targeted recruitment of individuals experiencing prolonged sense loss. This would increase statistical confidence when declaring no association with the other factors assessed, avoiding type II errors.

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.

The Relationships Among Periodontitis, Pneumonia and COVID-19

Periodontitis is a chronic inflammatory disease of the supporting structures of the teeth that affects approximately half of adults 30 years and older. There is increasing interest in the direct and indirect relationships between periodontitis and systemic diseases, including respiratory diseases. The aim of this study was to assess the evidence on links among periodontitis, pneumonia, and COVID-19. Oral and periodontal bacteria may be linked to respiratory disease directly by aspiration of pathogens into the lungs causing pneumonia. As SARS-CoV-2 began to spread worldwide in 2020, questions have arisen of how periodontal disease may also be connected to SARS-CoV-2 infection and severity, including potential replication and dissemination of the virus from periodontal pockets. Some proposed mechanisms include the oral cavity acting as a reservoir or point of entry for SARS-CoV-2, overgrowth of periodontal pathogens, and increased production of proinflammatory cytokines. Due to potential links between periodontal disease and respiratory infections like pneumonia and SARS-CoV-2, oral hygiene and management of periodontitis remain essential to help reduce infection and transmission of SARS-CoV-2.

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.