Periodontal tissues are targets for Sars-Cov-2: a post-mortem study

Herpesviruses and SARS-CoV-2: Viral Association with Oral Inflammatory Diseases

The oral cavity is a niche for diverse microbes, including viruses. Members of the Herpesviridae family, comprised of dsDNA viruses, as well as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), an ssRNA virus, are among the most prevalent viruses infecting the oral cavity, and they exhibit clinical manifestations unique to oral tissues. Viral infection of oral mucosal epithelia triggers an immune response that results in prolonged inflammation. The clinical and systemic disease manifestations of HHV have been researched extensively, and several recent studies have illuminated the relationship between HHV and oral inflammatory diseases. Burgeoning evidence suggests the oral manifestation of SARS-CoV-2 infection includes xerostomia, dysgeusia, periodontal disease, mucositis, and opportunistic viral and bacterial infections, collectively described as oral post-acute sequelae of COVID-19 (PASC). These diverse sequelae could be a result of intensified immune responses initially due to the copious production of proinflammatory cytokines: the so-called "cytokine storm syndrome", facilitating widespread oral and non-oral tissue damage. This review explores the interplay between HHV, SARS-CoV-2, and oral inflammatory diseases such as periodontitis, endodontic disease, and peri-implantitis. Additionally, the review discusses proper diagnostic techniques for identifying viral infection and how viral diagnostics can lead to improved overall patient health.

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.

COVID-19 on Oral Health: A New Bilateral Connection for the Pandemic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and transmission are generally known to be produced by respiratory droplets and aerosols from the oral cavity (O.C.) of infected subjects, as stated by the World Health Organization. Saliva also retains the viral particles and aids in the spread of COVID-19. Angiotensin-converting enzyme Type 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) are two of the numerous factors that promote SARS-CoV-2 infection, expressed by O.C. structures, various mucosa types, and the epithelia of salivary glands. A systemic SARS-CoV-2 infection might result from viral replication in O.C. cells. On the other hand, cellular damage of different subtypes in the O.C. might be associated with various clinical signs and symptoms. Factors interfering with SARS-CoV-2 infection potential might represent fertile ground for possible local pharmacotherapeutic interventions, which may confine SARS-CoV-2 virus entry and transmission in the O.C., finally representing a way to reduce COVID-19 incidence and severity.

COVID-19 in Dental Practice Is Prevented by Eugenol Responsible for the Ambient Odor Specific to Dental Offices: Possibility and Speculation

Dental professionals routinely work in proximity to patients even when either or both of them have suspected or confirmed COVID-19. The oral cavity also serves as a reservoir for SARS-CoV-2 because the virus is present in and replicates in oral secretions (saliva and gingival crevicular fluid), oral tissues (salivary gland and periodontal tissue), and oral microenvironments (gingival sulcus and periodontal pocket). Despite a high risk of SARS-CoV-2 infection, the prevalence of COVID-19 in dentists, dental hygienists, dental assistants, and their patients was similar to that in the general population even during the pandemic. We propose that eugenol, which is responsible for the ambient odor specific to dental offices, could contribute to prevention of COVID-19 in dental settings. Eugenol is not only released from dental materials (filling, cement, and sealer) but is also aerosolized by dental procedures (grinding, polishing, and restoration). Such eugenol has been suggested to possess the potential to inhibit the infectivity and replication of SARS-CoV-2, the entry of SARS-CoV-2 into human cells by binding specifically to the viral spike protein, and the protease indispensable for SARS-CoV-2 replication. It has been shown that aerosolized eugenol acts on airborne viruses to reduce their loads. This review highlights a hypothesis that the environment of dental offices impregnated with eugenol suppresses SARS-CoV-2 airborne transmission and SARS-CoV-2 contagion between dental professionals and patients, preventing COVID-19 in dental practice. Anti-COVID-19 eugenol might give insights into the safe delivery of dental treatment and oral care in the COVID-19 era.

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.

Biogeographical Impacts of Dental, Oral, and Craniofacial Microbial Reservoirs

The human mouth, or oral cavity, is at the crossroads of our external and internal environments, and it is increasingly evident that local colonization of dental, oral, and craniofacial (DOC) tissues and cells by bacteria and viruses may also have systemic effects across myriad diseases and disorders. Better understanding of this phenomenon will require a holistic understanding of host-microbial interactions in both spatiotemporal and biogeographical contexts while also considering person-, organ-, tissue-, cell-, and molecular-level variation. After the acute phase interaction with microbes, the establishment of site-specific reservoirs constitutes an important relationship to understand within the human body; however, despite a preliminary understanding of how viral reservoirs originate and persist across the human body, the landscape of single-cell and spatial multiomic tools has challenged our current understanding of what cells and niches can support microbial reservoirs. The lack of complete understanding impacts research into these relevant topics and implementing precision care for microbial-induced or microbial-influenced diseases. Here, via the lens of acute and chronic microbial infections of the DOC tissues, the goal of this review is to highlight and link the emerging spatiotemporal biogeography of host-viral interactomics at 3 levels: (1) DOC cell types in distinct tissues, (2) DOC-associated microbes, and (3) niche-specific DOC pathologies. Further, we will focus on the impact of postacute infectious syndromes such as long COVID, neurodegenerative disorders, and other underappreciated postviral conditions. We will provide hypotheses about how DOC tissues may play roles systemically in these conditions. Throughout, we will underscore how COVID-19 has catalyzed a new understanding of these biological questions, discuss future directions to study these phenomena, and highlight the utility of noninvasive oral biofluids in screening, monitoring, and intervening to prevent and/or ameliorate human infectious diseases.

Unraveling the Link between Periodontitis and Coronavirus Disease 2019: Exploring Pathogenic Pathways and Clinical Implications

Periodontitis involves the inflammation of the periodontal tissue, leading to tissue loss, while coronavirus disease 2019 (COVID-19) is a highly transmissible respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is amplified by poor systemic health. Key facilitators of SARS-CoV-2's entry into host cells are angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). This review reveals that periodontal pockets can serve as a hotspot for virus accumulation, rendering surrounding epithelia more susceptible to infection. Given that ACE2 is expressed in oral mucosa, it is reasonable to suggest that poor periodontal health could increase the risk of COVID-19 infection. However, recent studies have not provided sufficient evidence to imply a significant effect of COVID-19 on periodontal health, necessitating further and more long-term investigations. Nevertheless, there are hypotheses linking the mechanisms of the two diseases, such as the involvement of interleukin-17 (IL-17). Elevated IL-17 levels are observed in both COVID-19 and periodontitis, leading to increased osteoclast activity and bone resorption. Lastly, bidirectional relationships between periodontitis and systemic diseases like diabetes are acknowledged. Given that COVID-19 symptoms may worsen with these conditions, maintaining good oral health and managing systemic diseases are suggested as potential ways to protect against COVID-19.

Dental calculus - An emerging bio resource for past SARS CoV2 detection, studying its evolution and relationship with oral microflora

The most grievous threat to human health has been witnessed worldwide with the recent outbreak of Corona virus disease 2019 (COVID-19). There is mounting evidence available regarding theconnect of COVID -19 and oral cavity, particularly periodontal disease. The current review provides an update on the diagnostic potential of dental calculus and how this bio resource may help in providing us huge amount of diagnostic regarding the causative virus. Contemporary standard method of diagnosis via nasopharyngeal swabs (NPS) is tedious, may enhance the risk of aerosol contamination by inducing sneezing and detects the presence of active infection only.However,dental calculus being a mineralized deposit serves as a reservoir for biomoleculesand provides detection of past SARS CoV2 infection. Further, the abundance of information that can be obtained from this remarkable mineralized deposit on teeth regarding the viral genome, its evolution and interactions with the oral microflora shall enhance the understanding of the viral disease process and its connection with the periodontal disease. Additional diagnostic information, which may be obtained from this simple bio reservoir can complement the contemporary diagnostic strategies adopted in the management of COVID-19pandemic and enhance our existing knowledge for developing improvised novel approaches to mitigate the effects of mutated variants of the infectious agent.

Detection of SARS-CoV-2 and Its Related Factors on the Mucosal Epithelium of the Tongue

SARS-CoV-2 infects a variety of tissues, including the oral cavity. However, there are few reports examining the association of SARS-CoV-2 with tongue mucosal tissues with sticky tongue debris. This study investigated the presence of SARS-CoV-2 and its associated molecules by dissecting tongue tissue from autopsy specimens of 23 patients who died of COVID-19-related illness (pneumonia). Immunohistochemical staining, electron microscopy, and PCR analysis were performed on the tongue tissue specimens. The mucosal epithelium of the tongue formed a very thick keratinized with well-developed filiform papillae in all cases. ACE2 and TMPRSS2 were consistently co-expressed in all samples in the epithelium. The S-protein was strongly expressed in basal cells and the epithelial surface. S-protein-positive viral particles were detected in the tongue's stratified squamous epithelium via an immunoelectron microscope. Based on PCR amplification of the N1 and N2 regions, the SARS-CoV-2 gene was detected on the tongue epithelium, tongue submucosa, and in tongue debris. This suggests that tongue debris, including the squamous epithelial tissue, could be a source of SARS-CoV-2 in saliva. Furthermore, removing tongue debris may decrease the amount of SARS-CoV-2 in the oral cavity.

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.

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.

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.

Efficacy of mouthrinses in reducing oral SARS-COV-2 load: a review

Accumulated evidence has shown that the oral cavity may be an important reservoir for SARS-CoV-2. Some authors have suggested that the use of mouthrinses could reduce SARS-CoV-2 viral load in the saliva. Thus, the aim of this review was to synthesize evidence about the efficacy of mouthrinses in reducing the salivary viral load of SARS-CoV-2. 2. Nine randomized controlled trials (RCTs) have investigated the efficacy of different mouthrinses in reducing salivary SARS-CoV-2 loads. Various active ingredients have been tested in these trials: 0.5%,1% and 2% povidone-iodine, 0.2% and 0.12% chlorhexidine (CHX), 0.075% cetylpyridinium chloride (CPC), 0.075% CPC with Zinc lactate, 1% and 1.5% hydrogen peroxide (HP), 1.5% HP + 0.12% CHX and ß-cyclodextrin and citrox. The studies reported an intra-group reduction in the salivary levels of the virus, when compared with the baseline. However, the majority of these trials failed to demonstrate a significant inter-group difference between active groups and the control group relative to the decrease in salivary SARS-CoV-2 loads. Although promising, these results should be confirmed by larger trials.

The Oral Cavity Potentially Serving as a Reservoir for SARS-CoV-2 but Not Necessarily Facilitating the Spread of COVID-19 in Dental Practice

Intraoral tissues, secretions, and microenvironments may provide severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with the conditions necessary for viral cellular entry and inhabitation. The aim of the present study is to overview the oral cavity that potentially serves as a reservoir for SARS-CoV-2, and then discuss the possibility that such oral cavity facilitates the spread of coronavirus disease 2019 (COVID-19) in dental practice. Articles were retrieved from PubMed/Medline, LitCovid, ProQuest, Google Scholar, and preprint medRxiv databases. Results of the literature search indicated that SARS-CoV-2 host cell entry-relevant receptor and virus/cell membrane fusion mediators are expressed in major and minor salivary glands, tongue, taste bud, periodontal tissue, and dental pulp, which would be a target and reservoir for SARS-CoV-2. SARS-CoV-2 is present in saliva and gingival crevicular fluid of COVID-19 patients. These secretions would contaminate dental aerosol and droplet with SARS-CoV-2. SARS-CoV-2 inhabits periodontal pocket, gingival sulcus, and dental caries lesion, which could provide SARS-CoV-2 with a habitat. SARS-CoV-2 ribonucleic acid is preserved in dental calculus, which may inform of the previous infection with SARS-CoV-2. Despite involvement of the oral cavity in SARS-CoV-2 transmission and infection, to date, there have been no clusters of COVID-19 in dental practice. Dental settings are much less likely to facilitate the spread of COVID-19 compared with general medical settings, which may be explained by the situation of dentistry that the number of patients to visit dental offices/clinics was decreased during the COVID-19 pandemic, the characteristics of dentistry that dental professionals have maintained high awareness of viral infection prevention, adhered to a strict protocol for infection control, and been using personal protective equipment for a long time, the experimental results that dental devices generate only small amounts of aerosol responsible for the airborne viral transmission, irrigant from the dental unit contributes to the aerosol microbiota much rather than saliva, and the commonly used evacuation or suction system effectively reduces aerosol and droplet generation, and the possibility that human saliva exhibits the antiviral activity and the property to inhibit SARS-CoV-2 infection. It is considered that dental treatment and oral health care can be delivered safely in the COVID-19 era.

Autopsy findings of COVID-19 in children: a systematic review and meta-analysis

Clinical features of COVID-19 range from mild respiratory symptoms to fatal outcomes. Autopsy findings are important for understanding COVID-19-related pathophysiology and clinical manifestations. This systematic study aims to evaluate autopsy findings in paediatric cases. We searched PubMed, EMBASE, and Cochrane Database Reviews. We included studies that reported autopsy findings in children with COVID-19. A total of 11 studies (24 subjects) were included. The mean age of patients was 5.9 ± 5.7 years. Grossly, there was pericardial and pleural effusion, hepatosplenomegaly, cardiomegaly, heavy soft lung, enlarged kidney, and enlarged brain. The autopsy findings of the lungs were diffuse alveolar damage (78.3%), fibrin thrombi (43.5%), haemorrhage (30.4%), pneumonia (26%), congestion and oedema (26%), angiomatoid pattern (17.4%), and alveolar megakaryocytes (17.4%). The heart showed interstitial oedema (80%), myocardial foci of band necrosis (60%), fibrin microthrombi (60%), interstitial and perivascular inflammation (40%), and pancarditis (30%). The liver showed centrilobular congestion (60%), micro/macrovesicular steatosis (30%), and arterial/venous thrombi (20%). The kidney showed acute tubular necrosis (75%), congestion (62.5%), fibrin thrombi in glomerular capillaries (37.5%), and nephrocalcinosis, mesangial cell hyperplasia, tubular hyaline/granular casts (25% each). The spleen showed splenitis (71.4%), haemorrhage (71.4%), lymphoid hypoplasia (57.1%), and haemophagocytosis (28.6%). The brain revealed oedema (87.5%), congestion (75%), reactive microglia (62.5%), neuronal ischaemic necrosis (62.5%), meningoencephalitis (37.5%), and fibrin thrombi (25%). SARS-CoV-2 and CD68 were positive by immunohistochemistry in 85.7% and 33.3% cases, respectively. Autopsy findings of COVID-19 in children are variable in all important organs. It may help in better understanding the pathogenesis of SARS-CoV-2.

USE OF MOUTHWASH AND DENTIFRICE CONTAINING AN ANTIMICROBIAL PHTHALOCYANINE DERIVATIVE FOR THE REDUCTION OF CLINICAL SYMPTOMS OF COVID-19: A RANDOMIZED TRIPLE-BLIND CLINICAL TRIAL

PURPOSE

This clinical trial aimed to evaluate the use of mouthwash and dentifrice containing an antimicrobial phthalocyanine derivative (APD) to reduce the clinical symptoms in patients with COVID-19.

METHODS

This randomized, triple-blind clinical trial enrolled 134 patients aged 18 years or older who underwent COVID-19 testing through the use of nasopharyngeal swab RT-qPCR in a reference center for the diagnosis of COVID-19, had no clinical contraindications to mouthwash and gargle, and had access to cell phones with communication applications. According to the use of a mouthwash and dentifrice containing antimicrobial phthalocyanine derivatives (APD), patients were randomly assigned (1:1) to the APD or non-APD (control) group. All participants were instructed to floss twice a day, brush teeth for 2 minutes 3 times a day, and gargle/rinse (5 mL) for 1 min/3 times a day for 7 days. An online questionnaire was sent to collect data on the clinical symptoms of COVID-19 3 times: T0 (baseline before using the oral hygiene products), T3 (3 days after), and T7 (7 days after). The investigators, patients, and outcome assessors were blinded to group assignment. The Mann-Whitney, Chi-Square, Fisher's exact, and Cochran's tests were used according to the nature of the variables studied, with the level of significance set at P < .05.

RESULTS

No statistically significant difference was found in the prevalence of symptoms between groups at baseline. A statistically significant reduction in clinical symptoms was found in the control group (fatigue, shortness of breath, hoarse voice, sore throat, nasal congestion, and chest pain) and APD group (cough, fatigue, shortness of breath, hyposmia/anosmia, dysgeusia, hoarse voice, sore throat, nasal congestion, chest pain, diarrhea, and irritability/confusion) during the follow-up period. There were statistically significant differences, with a higher prevalence of symptoms in the control group at T3 and T7. Dysgeusia, sore throat, and irritability/confusion were less prevalent in the APD group at T3, and shortness of breath, hyposmia/anosmia, dysgeusia, hoarse voice, sore throat, diarrhea, and irritability/confusion were more prevalent in the control group at T7.

CONCLUSIONS

Based on this methodology, the results demonstrated that the regular use of mouthwash and dentifrice-containing APD had a positive impact on the clinical symptoms, as reported by patients with COVID-19.

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.

Self-Reported Periodontal Disease and Its Association with SARS-CoV-2 Infection

Introduction: Knowledge of the oral manifestations associated with SARS-CoV-2 infection, the new coronavirus causing the COVID-19 pandemic, was hindered due to the restrictions issued to avoid proximity between people and to stop the rapid spread of the disease, which ultimately results in a hyperinflammatory cytokine storm that can cause death. Because periodontal disease is one of the most frequent inflammatory diseases of the oral cavity, various theories have emerged postulating periodontal disease as a risk factor for developing severe complications associated with COVID-19. This motivated various studies to integrate questions related to periodontal status. For the present work, we used a previously validated self-report, which is a useful tool for facilitating epidemiological studies of periodontal disease on a large scale. Methodology: A blinded case-control study with participants matched 1:1 by mean age (37.7 years), sex, tobacco habits and diseases was conducted. After the diagnostic samples for SARS-CoV-2 detection were taken in an ad hoc location at Guadalajara University, the subjects were interviewed using structured questionnaires to gather demographic, epidemiological and COVID-19 symptom information. The self-reported periodontal disease (Self-RPD) questionnaire included six questions, and subjects who met the criteria with a score ≥ 2 were considered to have periodontal disease. Results: In total, 369 participants were recruited, with 117 participants included in each group. After indicating the subjects who had self-reported periodontal disease, a statistically significant difference (p value ≤ 0.001) was observed, showing that self-reported periodontal disease (n = 95, 85.1%) was higher in SARS-CoV-2-positive individuals than in controls (n = 66, 56.4%), with an OR of 3.3 (1.8-6.0) for SARS-CoV-2 infection in people with self-reported periodontal disease. Cases reported a statistically higher median of symptoms (median = 7.0, Q₁= 5.5, Q₃ = 10.0) than controls (p value ≤ 0.01), and cases with positive self-RPD had a significantly (p value ≤ 0.05) higher number of symptoms (median = 8.0, Q₁ = 6.0, Q₃ = 10.0) in comparison with those who did negative self-RPD (median = 6.0, Q₁ = 5.0, Q₃ = 8.0). Conclusions: According to this study, self-reported periodontal disease could be considered a risk factor for SARS-CoV-2 infection, and these individuals present more symptoms.

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.

Covid-19 and SARS-CoV-2 infection in periodontology: A narrative review

The present review examined the available evidence on possible involvement of gingival tissues in SARS‐CoV‐2 infection. Gingival tissue possess SARS‐CoV‐2 entry and transmission factors, among them ACE2 (angiotensin‐converting enzyme 2) and TMPRSS2 (transmembrane protease serine 2), which are the principal mediators of the virus cell invasion. Clinical observations reveal SARS‐CoV‐2 RNA in periodontal tissues and crevicular fluid, suggesting that the periodontium may act as an entry point for the virus and/or as a dissemination site. The preliminary observations prove infection potential of gingival crevicular fluid and shed epithelial cells from the periodontium. There are also findings on potential associations between periodontitis and Covid‐19 (coronavirus disease 2019). PubMed and Scopus databases were used to search for suitable keywords such as: SARS‐CoV‐2, Covid‐19, oral virus infection, gingival crevicular fluid, oral mucosa, periodontium, gingiva, ACE2, TMPRSS2, Furin, diagnosis, topical treatment, vaccine and the related words for relevant publications. Data extraction and quality valuation of articles were performed by the author. The review addressed seven major domains: periodontal structures as SARS‐CoV‐2 infection site, the periodontal changes under SARS‐CoV‐2 infection, potential associations between periodontitis and Covid‐19, periodontal oral care in Covid‐19, crevicular fluid as potential transmission factor and preventive measures. The search process in PubMed and Scopus was updated up to 31 March 2022. Finally 68 articles were retrieved for the final analysis, from the initial database searches. According to the inclusion criteria articles in English language without any date restriction were included. The included studies were mostly original articles, and published in 2020 and 2021 with the aim to describe Covid‐19 and SARS‐CoV‐2 infection in periodontology. As a conclusion it can be stated that gingival tissues may play a role in SARS‐CoV‐2 infection.

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.

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.

Biosafety in Dental Health Care During the COVID-19 Pandemic: A Longitudinal Study

Background

The coronavirus disease 2019 (COVID-19) pandemic had quite an impact on dental health care. Concerns about the risk of SARS-CoV-2 transmission through contaminant fluids and droplet formation during several dental procedures highly impacted dental health care, drastically reducing the number of dental practices worldwide. To monitor SARS-CoV-2 contamination in dental clinics, a longitudinal study was carried out during the return of dental practice at university.

Methods

Dental health care professionals [(DHCPs); teachers, undergraduate dental students, and dental assistants] and patients were screened for SARS-CoV-2 RNA in a dental school clinic environment from 11th January to 12th March 2021 (9 weeks). Serological testing was performed on DHCPs in two-time points. Additionally, samples with low Ct values were sequenced to identify the circulating SARS-CoV-2 variant and possible transmission clusters.

Results

We found a low number of dental staff (5.8%), patients (0.9%), and environment sites (0.8%) positive for SARS-CoV-2. Most positive cases had asymptomatic to mild symptoms, and two asymptomatic DHCPs presented prolonged infection. In the first week after previous exposure to COVID-19, 16.2% of DHCPs had IgM or IgG antibodies against SARS-CoV-2, and 1/3 of them had undetected antibodies in the last weeks. The variant zeta (P.2) could be detected. No cross-infection was observed between participants.

Conclusion

Our study suggests that dental practice can be safely executed when adequate control measures and biosafety protocols are applied. DHCP and patient testing, patient telemonitoring, proper use of personal protection equipment, and sanitization of surfaces are essential to avoid SARS-CoV-2 cross-infection in dental practice.

Periodontitis promotes the expression of gingival transmembrane serine protease 2 (TMPRSS2), a priming protease for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Objectives

The oral cavity is one of the main entry sites for SARS-CoV-2. Gingival keratinocytes express transmembrane serine protease 2 (TMPRSS2), responsible for priming the SARS-CoV-2 spike protein. We investigated whether periodontitis increased the expression of TMPRSS2.

Methods

To investigate gene expression in periodontitis, we analyzed the expression of specific genes from (1) the Gene Expression Omnibus (GEO) dataset of 247 human gingival tissues and (2) an experimentally-induced periodontitis mouse model. Human gingival tissues with or without periodontitis were immunohistochemically stained using an anti-TMPRSS2 antibody. Analysis of the TMPRSS2 promoter was performed using a ChIP-Atlas dataset. TMPRSS2 expression was detected in cultured human keratinocytes using quantitative reverse transcription (qRT)-PCR and Western blot analysis.

Results

GEO dataset analysis and an experimentally-induced periodontitis model revealed increased expression of TMPRSS2 in periodontitis gingiva. The keratinocyte cell membrane in periodontitis gingiva was strongly immunohistochemically stained for TMPRSS2. Using ChIP-Atlas and GEO datasets, we screened for transcription factors that bind to the TMPRSS2 promoter region. We found one candidate, estrogen receptor 1 (ESR1), highly expressed in periodontitis gingiva. Analysis of the GEO dataset revealed a correlation between ESR1 and TMPRSS2 expression in gingival tissues. An ESR1 ligand induced TMPRSS2 expression in cultured keratinocytes.

Conclusions

Periodontitis increases TMPRSS2 expression in the cell membrane of gingival keratinocytes.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) viral positivity and their burden in saliva of asymptomatic carriers - a systematic review and meta-analysis

AIMS

The coronavirus disease 2019 (COVID-19) due to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can present either as an asymptomatic carrier state or an acute respiratory disease, with or without severe pneumonia. The asymptomatic carriers are a challenge for the dental profession as the infection could be transmitted via virus-laden, and saliva in dental settings through aerosol-generating procedures (AGPSs). The aim of this review was to perform a systematic review of SARS-CoV-2 in the saliva of asymptomatic individuals.

MATERIALS AND METHODS

PubMed, Google scholar, and MedRxiv databases were searched between and a systematic review and meta-analysis of the available data were performed to assess the viral burden in the saliva of asymptomatic carriers of SARS-CoV-2. All investigators of the included studies used qRT-PCR to detect SARS-CoV-2 and yield quantitative data (the Ct values) appertaining to the viral load.

RESULTS

A total of 322 records in the English literature were identified, and eight studies with 2642 SARS-CoV-2-positive and asymptomatic individuals were included in the final analysis. Of these, 16.7% (95% CI: 11-23%) yielded SARS-CoV-2-positive saliva samples in comparison to 13.1% (95% CI: 12-17%) of the respiratory specimens (nasopharyngeal or nose-throat swabs).

CONCLUSION

As approximately 1 in 5 to 1 in 10 asymptomatic individuals harbour SARS-CoV-2 in either saliva or respiratory secretions, our results highlight the need for continued vigilance and the critical importance of maintaining strict, additional infection control regimens for the foreseeable future to mitigate the potential risks of COVID-19 transmission in dentistry.

Lack of direct association between oral mucosal lesions and SARS-CoV- 2 in a cohort of patients hospitalised with COVID-19

Background

COVID-19 is a disease affecting various human organs and systems, in which the virus seeks to interact with angiotensin-converting enzyme 2 receptors. These receptors are present in the oral cavity, but the direct relationship between such an interaction and possible oral manifestations of COVID-19 is still unclear.

Aim

The present study evaluated oral manifestations in a cohort of COVID-19 patients during the period of hospitalisation.

Methods

In total, 154 patients presenting moderate-to-severe forms of COVID-19 had their oral mucosa examined twice a week until the final outcome, either discharge or death. The oral alterations observed in the patients were grouped into Group 1 (pre-existing conditions and opportunistic oral lesions) and Group 2 (oral mucosal changes related to hospitalization).

Results

Oral lesions found in the patients of Group 1 are not suggestive of SARS-CoV-2 infection as they are mainly caused by opportunistic infections. On the other hand, oral alterations found in the patients of Group 2 were statistically (P < 0.001) related to intubation and longer period of hospitalisation.

Conclusion

It is unlikely that ulcerative lesions in the oral cavity are a direct manifestation of SARS-CoV-2 or a marker of COVID-19 progression.

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.

SARS-CoV-2 RNA in dental biofilms: Supragingival and subgingival findings from inpatients in a COVID-19 intensive care unit

BACKGROUND

Saliva, salivary glands, gingival crevicular fluid, and supragingival biofilms may harbor SARS-CoV-2 RNA. This observational study aimed to investigate the presence and load of SARS-CoV-2 RNA in supragingival, and subgingival biofilms obtained from intensive care unit (ICU) patients.

METHODS

A convenience sample, composed of 52 COVID-19+ participants (48.6 ± 14.8 years, 26.9% females), were evaluated for pre-existing comorbidities, number of teeth and periodontal data [visible plaque (VPI), bleeding on probing (BOP), periodontal probing depth (PPD), and attachment loss (AL)]. Supragingival and subgingival samples (SubDeep: four sites with the deepest PPD; SubRemain: remaining shallower sites) were analyzed by RT-qPCR with corresponding cycle quantification (Cq). Statistical analyses considered the individual (p = 5%).

RESULTS

Twenty-six participants tested positive for dental biofilms (Biofilm+) with 96.2% of them being positive for subgingival samples. Pre-existing comorbidities, number of teeth examined, VPI, PPD, AL, and BOP were similar between Biofilm+ and Biofilm-. SubDeep PPD (3.72±0.86), AL (4.34±1.33), and % of BOP (66.0±31.1) values were significantly greater compared to SubRemain values (2.84±0.48, 3.37±0.34, and 20.4±24.1, respectively). Biofilm+ Cqs showed no association with the periodontal condition. Cqs from Nasopharynx/Oropharynx (Naso/Oro; n = 36) were similar between Biofilm+ and Biofilm- participants. Length of time since ICU intake, last Naso/Oro RT-qPCR readings, onset of COVID-19 symptoms, and biofilm samplings were greater for Biofilm-.

CONCLUSIONS

ICU patients harbored SARS-CoV-2 RNA in supragingival and subgingival biofilms, irrespective of the periodontal condition and systemic viral load. The high number of positive patients highlights the need to better understand this habitat to provide adequate oral care. This article is protected by copyright. All rights reserved.

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.

Oral Pathology in COVID-19 and SARS-CoV-2 Infection-Molecular Aspects

This review article was designed to evaluate the existing evidence related to the molecular processes of SARS-CoV-2 infection in the oral cavity. The World Health Organization stated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and transmission is produced by respiratory droplets and aerosols from the oral cavity of infected patients. The oral cavity structures, keratinized and non-keratinized mucosa, and salivary glands' epithelia express SARS-CoV-2 entry and transmission factors, especially angiotensin converting enzyme Type 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). Replication of the virus in cells leads to local and systemic infection spread, and cellular damage is associated with clinical signs and symptoms of the disease in the oral cavity. Saliva, both the cellular and acellular fractions, holds the virus particles and contributes to COVID-19 transmission. The review also presents information about the factors modifying SARS-CoV-2 infection potential and possible local pharmacotherapeutic interventions, which may confine SARS-CoV-2 virus entry and transmission in the oral cavity. The PubMed and Scopus databases were used to search for suitable keywords such as: SARS-CoV-2, COVID-19, oral virus infection, saliva, crevicular fluid, salivary gland, tongue, oral mucosa, periodontium, gingiva, dental pulp, ACE2, TMPRSS2, Furin, diagnosis, topical treatment, vaccine and related words in relevant publications up to 28 December 2021. Data extraction and quality evaluation of the articles were performed by two reviewers, and 63 articles were included in the final review.

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.

Population-based virucidal phthalocyanine gargling/rinsing protocol to reduce the risk of coronavirus disease-2019: a community trial

Aim

In this community trial, the objective was to evaluate the incidence of coronavirus disease-2019 (COVID-19) cases in two similar communities in three distinct phases: 1 (before the intervention), 2 (during the intervention), and 3 (after the intervention).

Methods

The test community received the oral antiseptic intervention (experimental), while the control community did not. The official information agency ("Statewise System for Data Analysis") provided the number of confirmed COVID-19 cases. Data were analyzed according to the three phases per epidemiological week (epi) using the R Core Team (2021) program. The relative risk and 95% confidence intervals between the cumulative incidence values of the test and control communities were calculated for each period. In the test community, a total of 995 residents over 10 years of age received two bottles containing 600 ml of mouthwash containing antiviral phthalocyanine derivative (APD). The participants were asked to gargle/rinse with of 5 mL of the mouthwash containing ADP 3 to 5 times a day, for 1 min, until the bottles were empty.

Results

In phases 1 and 3, the disease risk between the two communities did not differ significantly (p>0.05), while in phase 2, the disease risk was 54% lower in the test community than in the control community.

Conclusion

The use of the APD mouthwash protocol seems to reduce the COVID-19 incidence at the population level, and further studies are needed to confirm its protective effect under more precisely controlled conditions.

Pros and Cons of CAD/CAM Technology for Infection Prevention in Dental Settings during COVID-19 Outbreak

The purpose of this commentary is to update the evidence reported in our previous review on the advantages and limitations of computer-aided design/computer-aided manufacturing technology in the promotion of dental business, as well as to guarantee patient and occupational safety. The COVID-19 pandemic led to an unprecedented focus on infection prevention; however, waves of COVID-19 follow one another, asymptomatic cases are nearly impossible to identify by triage in a dental setting, and the effectiveness of long-lasting immune protection through vaccination remains largely unknown. Different national laws and international guidelines (mainly USA-CDC, ECDC) have often brought about dissimilar awareness and operational choices, and in general, there has been very limited attention to this technology. Here, we discuss its advantages and limitations in light of: (a) presence of SARS-CoV-2 in the oral cavity, saliva, and dental biofilm and activation of dormant microbial infections; (b) the prevention of SARS-CoV-2 transmission by aerosol and fomite contamination; (c) the detection of various oral manifestations of COVID-19; (d) specific information for the reprocessing of the scanner tip and the ward from the manufacturers.

Ultrasound-Guided Minimally Invasive Tissue Sampling: A Minimally Invasive Autopsy Strategy During the COVID-19 Pandemic in Brazil, 2020

BACKGROUND

Minimally invasive autopsies, also known as minimally invasive tissue sampling (MITS), have proven to be an alternative to complete diagnostic autopsies (CDAs) in places or situations where this procedure cannot be performed. During the coronavirus disease 2019 (COVID-19) pandemic, CDAs were suspended by March 2020 in Brazil to reduce biohazard. To contribute to the understanding of COVID-19 pathology, we have conducted ultrasound (US)-guided MITS as a strategy.

METHODS

This case series study includes 80 autopsies performed in patients with COVID-19 confirmed by laboratorial tests. Different organs were sampled using a standardized MITS protocol. Tissues were submitted to histopathological analysis as well as immunohistochemical and molecular analysis and electron microscopy in selected cases.

RESULTS

US-guided MITS proved to be a safe and highly accurate procedure; none of the personnel were infected, and accuracy ranged from 69.1% for kidney, up to 90.1% for lungs, and reaching 98.7% and 97.5% for liver and heart, respectively. US-guided MITS provided a systemic view of the disease, describing the most common pathological findings and identifying viral and other infectious agents using ancillary techniques, and also allowed COVID-19 diagnosis confirmation in 5% of the cases that were negative in premortem and postmortem nasopharyngeal/oropharyngeal swab real-time reverse-transcription polymerase chain reaction.

CONCLUSIONS

Our data showed that US-guided MITS has the capacity similar to CDA not only to identify but also to characterize emergent diseases.

Minimally Invasive Tissue Sampling as an Alternative to Complete Diagnostic Autopsies in the Context of Epidemic Outbreaks and Pandemics: The Example of Coronavirus Disease 2019 (COVID-19)

Background

Infectious diseases’ outbreak investigation requires, by definition, conducting a thorough epidemiological assessment while simultaneously obtaining biological samples for an adequate screening of potential responsible pathogens. Complete autopsies remain the gold-standard approach for cause-of-death evaluation and characterization of emerging diseases. However, for highly transmissible infections with a significant associated lethality, such as COVID-19, complete autopsies are seldom performed due to biosafety challenges, especially in low-resource settings. Minimally invasive tissue sampling (MITS) is a validated new approach based on obtaining postmortem samples from key organs and body fluids, a procedure that does not require advanced biosafety measures or a special autopsy room.

Methods

We aimed to review the use of MITS or similar procedures for outbreak investigation up to 27 March 2021 and their performance for evaluating COVID-19 deaths.

Results

After a literature review, we analyzed in detail the results of 20 studies conducted at international sites, whereby 216 COVID-19–related deaths were investigated. MITS provided a general and more granular understanding of the pathophysiological changes secondary to the infection and high-quality samples where the extent and degree of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–related damage could be evaluated.

Conclusions

MITS is a useful addition in the investigation and surveillance of infections occurring in outbreaks or epidemics. Its less invasive nature makes the tool more acceptable and feasible and reduces the risk of procedure-associated contagion, using basic biosafety measures. Standardized approaches protocolizing which samples should be collected—and under which exact biosafety measures—are necessary to facilitate and expand its use globally.

Covid-19 and oral diseases: Crosstalk, synergy or association?

The coronavirus disease 2019 (Covid-19) is a viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that clinically affects multiple organs of the human body. Cells in the oral cavity express viral entry receptor angiotensin-converting enzyme 2 that allows viral replication and may cause tissue inflammation and destruction. Recent studies have reported that Covid-19 patients present oral manifestations with multiple clinical aspects. In this review, we aim to summarise main signs and symptoms of Covid-19 in the oral cavity, its possible association with oral diseases, and the plausible underlying mechanisms of hyperinflammation reflecting crosstalk between Covid-19 and oral diseases. Ulcers, blisters, necrotising gingivitis, opportunistic coinfections, salivary gland alterations, white and erythematous plaques and gustatory dysfunction were the most reported clinical oral manifestations in patients with Covid-19. In general, the lesions appear concomitant with the loss of smell and taste. Multiple reports show evidences of necrotic/ulcerative gingiva, oral blisters and hypergrowth of opportunistic oral pathogens. SARS-CoV-2 exhibits tropism for endothelial cells and Covid-19-mediated endotheliitis can not only promote inflammation in oral tissues but can also facilitate virus spread. In addition, elevated levels of proinflammatory mediators in patients with Covid-19 and oral infectious disease can impair tissue homeostasis and cause delayed disease resolution. This suggests potential crosstalk of immune-mediated pathways underlying pathogenesis. Interestingly, few reports suggest recurrent herpetic lesions and higher bacterial growth in Covid-19 subjects, indicating SARS-CoV-2 and oral virus/bacteria interaction. Larger cohort studies comparing SARS-CoV-2 negative and positive subjects will reveal oral manifestation of the virus on oral health and its role in exacerbating oral infection.

COVID-19 and oral diseases: Assessing manifestations of a new pathogen in oral infections

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a recently identified virus responsible for life-threatening coronavirus disease 19 (COVID-19). The SARS-CoV-2 infected subjects can be asymptomatic or symptomatic; the later may present a wide spectrum of clinical manifestations. However, the impact of SARS-CoV-2 on oral diseases remain poorly studied. Detection of SARS-CoV-2 in saliva indicates existence of virus in the oral cavity. Recent studies demonstrating the expression of ACE-2, a SARS-CoV-2 entry receptor, in oral tissues further strengthens this observation. Cytokine storm in severe COVID-19 patients and copious secretion of pro-inflammatory cytokines (IL-6, IL-1β and TNF-α) in multiple symptomatic oral pathologies including periodontitis and periapical periodontitis suggests that inflammatory microenvironment is a hallmark of both COVID-19 and oral diseases. Hyperinflammation may provide conducive microenvironment for the growth of local oral pathogens or opportunistic microbes and exert detrimental impact on the oral tissue integrity. Multiple case reports have indicated uncharacterized oral lesions, symptomatic irreversible pulpitis, higher plaque index, necrotizing/desquamative gingivitis in COVID-19 patients suggesting that SARS-CoV-2 may worsen the manifestations of oral infections. However, the underlying factors and pathways remain elusive. Here we summarize current literature and suggest mechanisms for viral pathogenesis of oral dental pathology derived from oral microbiome and oral mucosa-dental tissue interactions. Longitudinal studies will reveal how the virus impairs disease progression and resolution post-therapy. Some relationships we suggest provide the basis for novel monitoring and treatment of oral viral disease in the era of SARS-CoV-2 pandemic, promoting evidence-based dentistry guidelines to diagnose virus-infected patients to improve oral health.

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.

A case-control study on the association between periodontitis and coronavirus disease (COVID-19)

BACKGROUND

Coronavirus disease (COVID-19) and periodontitis share common characteristics, such as an exaggerated inflammatory response. As periodontal diseases were shown to be associated with respiratory diseases, such as pneumonia, it is quite possible that a relationship may exist between periodontitis and COVID-19. Hence, the aim of the present study was to determine whether periodontitis and poor oral hygiene are associated with COVID-19.

METHODS

A case-control study was conducted. Patients who had positive real-time reverse transcription polymerase chain reaction results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were included in the case group (n = 79), and patients with negative results were included in the control group (n = 71). The periodontal examination involved recording the plaque scores, calculus scores, tooth mobility, gingival bleeding, probing depth, recession, and clinical attachment level (CAL).

RESULTS

Logistic regression analysis showed significant associations of mean plaque scores ≥ 1 (odds ratio (OR), 7.01; 95% confidence interval (CI), 1.83 to 26.94), gingivitis (OR, 17.65; 95% CI, 5.95 to 52.37), mean CAL ≥ 2 mm (OR, 8.46; 95% CI, 3.47 to 20.63), and severe periodontitis (OR, 11.75; 95% CI, 3.89 to 35.49) with COVID-19; these findings were more prevalent in the case group.

CONCLUSION

Based on the above mentioned observations, it can be concluded that there is an association between periodontitis severity and COVID-19. Gingival bleeding and dental plaque accumulation are also more frequent among COVID-19 patients. Hence, it is essential to maintain periodontal health and good oral hygiene as an important measure for COVID-19 prevention and management.

Teledentistry System in Dental Health Public Services: A Mixed-Methods Intervention Study

INTRODUCTION

Health information and communication technologies, such as Teledentistry, can help expand access to dental health public services making it more effective.

OBJECTIVE

To analyze the factors that affect the implementation of a Teledentistry system in dental health public services.

METHODS

The study follows the Implementation Research methodological framework. A mixed-method approach was applied using a triangulation design-sequential model to collect, analyze, and interpret qualitative and quantitative data about the implementation of a Teledentistry system. A compulsory teleconsultation from the general dentist was planned to access periodontics specialized care. The study was developed in a South Brazilian capital city and the platform of the Santa Catarina Telehealth Center was used. Qualitative and quantitative data were collected sequentially to achieve a better understanding of implementation research issues.

RESULTS

In seven months, 68 teleconsulting was performed by 22% of the general dentists, prior to the referrals on periodontics. Only one reported not needing to refer the patient to the periodontist as a result of the teleconsulting guidance. Teledentistry system implementation and usage were influenced by the managers' political and administrative awareness to deploy and maintain the intervention. Lack of sufficient resource investment, lack of system integration, and internet failures were relevant limiting factors. The teleconsultant guidelines contributed to general dentistry's better decision-making regarding treatment, urgency of case management, and prioritization of referrals to the periodontists CONCLUSION: Identifying the factors that influence the implementation and finding solutions to overcome them, can prevent future failures and improve usage of the system.

Presence of SARS-CoV-2 and Its Entry Factors in Oral Tissues and Cells: A Systematic Review

Background and Objectives: The aim of this systematic review is to summarize the current data about the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its entry factors in oral tissues and cells. Materials and Methods: This systematic review was carried out based on the Preferred Reporting Items for a Systematic Review and Meta-Analysis (PRISMA). Three databases were analyzed (Pubmed, Web of science and Scopus) by three independent researchers. From the 18 identified studies, 10 of them met the inclusion criteria. The presence of SARS-CoV-2 or its entry factors (angiotensin-converting enzyme II (ACE2), transmembrane serine proteases (TMPRSS), and furin) was analyzed in these 10 studies during the pandemic. Results: ACE2 expression was analyzed in 9 of the 10 studies. ACE2 is expressed mainly in the tongue, oral mucosa, salivary glands and epithelial cells. The expression of the TMPRSS2 gene or protein was analyzed in 6 studies. These studies reported that the expression of TMPRSS2 was mainly in the salivary glands, tongue, sulcular epithelium and oral mucosa; as well as in cells of the salivary glands (ductal, acinar and myoepithelial cells) and the tongue (the spinous-based cell layer, horny layer and the epithelial surface). Other TMPRSS were also reported. The expression of TMPRSS3, TMPRSS4, TMPRSS5, TMPRSS7 and TMPRSS11D was reported mainly in salivary glands and in epithelial-type cells. Furan expression was analyzed in three studies. The expression of furin was detected mainly in epithelial cells of the tongue. A variety of methods were used to carry out the detection of SARS-CoV-2 or its input molecules. Conclusions: These results show that SARS-CoV-2 can infect a wide variety of oral tissues and cells, and that together with the theories dedicated to explaining the oral symptoms present in SARS-CoV-2 positive patients, it provides us with a good scientific basis for understanding the virus infection in the oral cavity and its consequences.

Salivary glands are a target for SARS-CoV-2: a source for saliva contamination

The ability of the new coronavirus SARS-CoV-2 to spread and contaminate is one of the determinants of the COVID-19 pandemic status. SARS-CoV-2 has been detected in saliva consistently, with similar sensitivity to that observed in nasopharyngeal swabs. We conducted ultrasound-guided postmortem biopsies in COVID-19 fatal cases. Samples of salivary glands (SGs; parotid, submandibular, and minor) were obtained. We analyzed samples using RT-qPCR, immunohistochemistry, electron microscopy, and histopathological analysis to identify SARS-CoV-2 and elucidate qualitative and quantitative viral profiles in salivary glands. The study included 13 female and 11 male patients, with a mean age of 53.12 years (range 8-83 years). RT-qPCR for SARS-CoV-2 was positive in 30 SG samples from 18 patients (60% of total SG samples and 75% of all cases). Ultrastructural analyses showed spherical 70-100 nm viral particles, consistent in size and shape with the Coronaviridae family, in the ductal lining cell cytoplasm, acinar cells, and ductal lumen of SGs. There was also degeneration of organelles in infected cells and the presence of a cluster of nucleocapsids, which suggests viral replication in SG cells. Qualitative histopathological analysis showed morphologic alterations in the duct lining epithelium characterized by cytoplasmic and nuclear vacuolization, as well as nuclear pleomorphism. Acinar cells showed degenerative changes of the zymogen granules and enlarged nuclei. Ductal epithelium and serous acinar cells showed intense expression of ACE2 and TMPRSS receptors. An anti-SARS-CoV-2 antibody was positive in 8 (53%) of the 15 tested cases in duct lining epithelial cells and acinar cells of major SGs. Only two minor salivary glands were positive for SARS-CoV-2 by immunohistochemistry. Salivary glands are a reservoir for SARS-CoV-2 and provide a pathophysiological background for studies that indicate the use of saliva as a diagnostic method for COVID-19 and highlight this biological fluid's role in spreading the disease. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

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.

Saliva: What Dental Practitioners Should Know about the Role of This Biofluid in the Transmission and Diagnostic of SARS-CoV-2

A novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has become a global ongoing pandemic. This pandemic represents a great work risk for all health professionals, it includes dental professionals who are in constant contact with saliva, which represents one of the main routes of transmission of the disease. This is due to the fact that a wide variety of oral tissues and cells are susceptible to infection by SARS-CoV-2 and that they express the ACE2 receptor, which is the main route of entry of the virus into cells, as well as the proteins TMPRSS and furin that contributes to the binding of the virus to the host cells. According to recent studies, some of the oral cells most susceptible to infection by SARS-CoV-2 are the epithelial cells of the salivary glands. This explains the presence of the virus in the saliva of infected patients and provides scientific evidence that supports the use of saliva as a biofluid that offers the opportunity to develop new detection and diagnostic techniques. This is because saliva is much easier to collect compared to nasopharyngeal swab. However, the presence of the virus in saliva, also represents a great source of transmission, since the main form of infection is through microscopic drops that are generated when infected people cough or sneeze. Likewise, health professionals, such as dentists are exposed to contagion through saliva. The objective of this review article is to provide a perspective on the main cells and tissues that can be affected by the virus, the risk of contagion that the presence of the virus in saliva represents for dentists; and the new techniques developed from saliva samples for the diagnosis and surveillance of SARS-CoV-2 infection. This review is expected to contribute to the knowledge of oral health professionals about the risk of saliva in the spread of SARS-CoV-2, but also its advantages as a diagnostic tool for pandemic control. In conclusion, the authors can mention that information that provides more scientific evidence of the mechanisms of infection of the coronavirus in oral cells and tissues is being published continually. This also explains the presence of the virus in the saliva of infected people and the risk of contagion that this means. It also provides scientific evidence of the use of saliva as a biofluid for the detection, diagnosis, monitoring, and control of the spread of the virus.

Nexus between COVID-19 and periodontal disease

Over the past several decades, studies have demonstrated the existence of bi-directional relationships between periodontal disease and systemic conditions. Periodontitis is a polymicrobial and multifactorial disease involving both host and environmental factors. Tissue destruction is primarily associated with hyperresponsiveness of the host resulting in release of inflammatory mediators. Pro-inflammatory cytokines play a major role in bacterial stimulation and tissue destruction. In addition, these cytokines are thought to underlie the associations between periodontitis and systemic conditions. Current research suggests that increased release of cytokines from host cells, referred to as the cytokine storm, is associated with disease progression in patients with coronavirus disease 2019 (COVID-19). An intersection between periodontitis and pulmonary disease is biologically plausible. Hence, we reviewed the evidence linking COVID-19, cytokines, and periodontal disease. Plaque control is essential to prevent exchange of bacteria between the mouth and the lungs, reducing the risk of lung disease. Understanding these associations may help identify individuals at high risk and deliver appropriate care at early stages.