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

Abstract

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 theĀ 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,Ā 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 (ORā€‰=ā€‰6.95, Pā€‰=ā€‰0.0008), ICU admissions (ORā€‰=ā€‰3.15, Pā€‰=ā€‰0.0001), and mortality (ORā€‰=ā€‰1.92, Pā€‰=ā€‰0.21). Additionally, compared to mild PD, severe PD was significantly associated with higher risks of severe COVID-19 outcomes: severe symptoms (Pā€‰=ā€‰0.02); ICU admission (Pā€‰=ā€‰0.0001); and higher mortality rates (Pā€‰=ā€‰0.0001). The results also revealed 58% higher risk for COVID-19 infection in patients with PD (Pā€‰=ā€‰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.

Peer Review reports

Background

The Corona virus disease of 2019 (COVID-19) caused by the SARS-CoV-2 virus has resulted in an enormous impact on the global health and economy [1,2,3]. Despite the fact that most COVID-19 patients recover without major complications, few patients still suffer severe complications including multiple organ failure and death [4, 5]. Such complications are driven by serious conditions triggered by the infection such severe acute respiratory distress, systemic inflammatory reactions, and coagulopathies [6, 7]. It became obvious that several comorbidities such as obesity, hypertension, diabetes and advanced age are associated with severe COVID-19 [4,5,6, 8]. A considerable fraction of apparently healthy and young patients, with no clear identifiable risk factors, however, still develops severe complications.

Periodontitis (PD), the most common form of periodontal diseases, is a chronic disease involving the inflammation and subsequent damage of the tissues surrounding the teeth [9]. If not treated properly, PD leads to the destruction of the bone surrounding the teeth and ultimately loss of the teeth themselves [10]. Beyond such local consequences, PD can also have detrimental effects on systemic health [10]. Growing evidence links PD to several systemic diseases including diabetes mellitus, cardiovascular diseases, pneumonia, metabolic syndrome, and cancers [9, 11,12,13,14,15,16,17]. Such systemic effects of PD might be ascribed to the bacterial products and inflammatory mediators in the periodontal infected tissues that can reach the blood stream and increase the systemic inflammatory burden [18]. Worth to mention that periodontal pathogens can reach the respiratory tract, aggravating, and/or even initiating respiratory infections [17].

Given that PD shares with COVID-19 many features including comorbidities and increased blood levels of inflammation and coagulation biomarkers, [19, 20] several researchers have hypothesized that PD could be associated with a higher risk of COVID-19, and the development of its adverse outcomes [20, 21]. Marouf et al. reported a higher risk of COVID-19 complications including death (ORā€‰=ā€‰8.81), intensive care unit (ICU) admission (ORā€‰=ā€‰3.54), and the need for assisted ventilation (ORā€‰=ā€‰4.57) in patients with periodontitis [22]. Gupta et al. reported that the likelihood of requiring assisted ventilation, hospital admission, death, and getting COVID-19-related pneumonia were 7.45, 36.52, 14.58, and 4.42 folds, respectively, in COVID-19 patients with PD compared to COVID-19 patients without PD [23]. Additionally, 2022 caseā€“control study among US COVID-19 patients reported significantly greater missing teeth and alveolar loss tooth in Covid-19 positive patients and in those with severe complications [24]. Interestingly, a 2022 caseā€“control study by Said et al. reported a significant association between history of periodontal therapy and favorable COVID-19 outcomes, indicating a positive role of periodontal therapy on Covid-19 complications [25]. Using a two-sample Mendelian randomization, Wang et al. revealed that PD was significantly associated with higher risk for COVID-19 infection and severe complications [26]. Conversely, two studies with a large sample size from UK Biobank cohorts did not support any significant association between PD and the risk and outcomes of COVID-19 [27, 28]. Similarly, a retrospective cross-sectional Dutch study did not find a significant association between alveolar bone loss and complications of COVID-19 [29]. One systematic review of two studies reported a significant association between PD and COVID-19 [30]. A more recent systematic review and meta-analysis by Baima et al., [31] investigating the potential link between PD and Covid-19, reported a significant association between PD and Covid-19 susceptibility and poor outcomes [31]. Nevertheless, the latter review included only very limited studies (nā€‰=ā€‰8; studies published up till Feb. 2022), and since then numerous relevant studies were published with interesting findings. Additionally, the latter two systematic reviews did not in-depth assess the correlation between severity of PD and severity of Covid-19 symptoms. Therefore, this systematic review and meta-analysis sought to comprehensively analyze and summarize the available evidence on the association between PD and COVID-19. The focused question was: Does periodontal health status have an impact on COVID-19 risk and clinical outcomes?

Materials and methods

The present systematic review and meta-analysis adhered strictly to the PRISMA 2020 guidelines and followed utterly PECO principles. This systematic review was registered in Open Science Framework (OSF) registries (https://doi.org/10.17605/OSF.IO/KW7TC). The PECO research question was: Is periodontal disease a risk factor for COVID-19 and its poor outcomes?

Eligibility criteria

All studies (cohort, caseā€“control, and cross-sectional and interventional studies) that assessed the association of periodontal diseases with COVID-19 outcomes in humans were eligible.

Exposure: periodontal disease parameters.

Outcome: COVID-19 infection and/or its associated adverse outcomes.

Case reports, post-mortem studies, animal and experimental studies, review articles, commentaries, and studies with unclear exposures/outcomes were excluded.

Search strategy and information sources

An extensive search of online databases (PubMed, Scopus, and Web of Science) and Google Scholar search engine, supplemented with manual search was conducted independently by two reviewers (SA and MA) on April 16th, 2023 for all relevant studies published from December 2019 up to April 15th, 2023. The following Mesh terms and free keywords were used: ("Periodontal Diseases"[Mesh] OR "Oral Health"[Mesh] OR ā€œPeriodontal diseaseā€ OR periodontitisā€ OR Periodont* OR periodontal pathogen*) AND ("SARS-CoV-2ā€³[Mesh] OR COVID-19). Detailed information about the search strategies is presented in Supplementary Table 1.

Screening and selection process

All retrieved studies were exported to the EndNote program, which eased removal of duplicates. Then, the titles and abstracts of all articles were screened independently by two reviewers (SA and FT), and irrelevant articles were excluded. The full-texts of all potentially eligible articles were independently evaluated by the two reviewers for inclusions, and irrelevant articles were eliminated.

Data extraction

All relevant data were independently extracted by two investigators (SA, MA) using customized forms. The extracted data included the following: first author name, country of the study, study design, sample size, age and gender of the participants, periodontal variables (exposure) and COVID-19 variables (the main outcomes).

Quality assessment

Two reviewers (SA and MA) assessed independently the quality of all included studies using the Newcastle Ottawa Scale (NOS) for assessing the quality of non-randomized studies [32]. Disagreements, if any, were resolved by discussion. The overall quality of each study was rated as either: high quality, 7ā€“9 stars; moderate quality, 4ā€“6 stars; or poor quality, 0ā€“3 stars [32].

Statistical analysis

The Review Manager (RevMan) Version 5.3 software was used for data analysis. The pooled odds ratios (ORs) along with 95% confidence intervals (CIs) were used to calculate the risk of COVID-19 and associated outcomes in patients with PD and periodontium healthy patients. Heterogeneity was evaluated using the Chi-square test and the I2 statistics. A Fixed-effects model was used for low/moderate heterogeneity (I2ā€‰ā‰¤ā€‰50%), while a random effect model was applied for significant heterogeneity (I2ā€‰>ā€‰50%).

Seā€‰nsitivity tests: due to the limited number of analyzed studies, no sensitivity tests were done.

Results

Study selection

FigureĀ 1 presents the search strategy of the present study. The initial online searches yielded 3002 articles, of which 2050 duplicate records were excluded. The titles and abstracts of 952 articles were screened for eligibility, and 895 were found irrelevant and thus excluded. The full-texts of the remaining 57 articles were assessed for eligibility, and 35 were excluded for various reasons (Supplementary Table 2). Eventually, 22 studies were included in the present systematic review, and 12 were pooled into the meta-analysis.

Fig. 1
figure 1

Flowchart of the search strategy

General characteristics of the included studies

A total of 22 studies, involving 92,535 patients were included in the present systematic review; [22,23,24,25, 27,28,29, 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47] of these, 12 studies were included in the meta-analysis [23, 25, 27, 28, 33, 35, 36, 40, 41, 43, 44, 46, 47]. Twelve of these studies were caseā€“control studies, [22,23,24,25, 29, 34, 35, 37, 38, 42, 44, 46] three cohort studies, [27, 28, 39] and seven cross-sectional studies [33, 36, 40, 41, 43, 45, 47]. Six studies were conducted in India [23, 34, 38, 40, 42, 44] three in the UK [27, 28, 39], two in Brazil [35, 36] two in Saudi Arabia [33, 43], two in Qatar [22, 25], two in Turkey [46, 47] and one each in: the Netherlands, [29]. Spain, [45] Egypt, [41] Mexico, [37] and the USA [24]. The mean age of the participants ranged from 38.2 to 68.6 years, with almost equal representation of both genders. Diagnosis of COVID-19 was confirmed by PCR test in all of the included studies.

Periodontal parameters (Exposure)

Ascertainment of periodontal parameters were highly variable across the included studies. One or more of the following periodontal parameters were considered: number of missing teeth, pocket depth, gum bleeding, alveolar bone loss, and loose teeth (Table 1). Similarly, ascertainment of the exposure methods varied greatly across the included studies: clinical examination in nine studies, [23, 34,35,36, 38, 40, 42, 44, 46] self-reported in five studies, [27, 28, 37, 39, 41] and dental radiographs in eight studies [22, 24, 25, 29, 33, 43, 45, 47].

Table 1 General characteristics of the included studies

Outcome measures

Most of the studies reported on adverse outcomes of Covid-19. Ascertainment of the adverse outcomes of COVID-19 included one or more of the following: severity of symptoms, ICU admission, hospital admission, and mortality (Table 1). Nine studies [24, 26,27,28, 34, 37,38,39, 46] also reported on the risk of covid-19 in periodontitis patients.

Qualitative results

The majority of the studies (19 studies) found a significant association between PD and COVID-19 adverse outcomes (i.e., severity of symptoms, hospital admission, ICU and mortality). Conversely, three studies did not report a significant association between PD and COVID-19 adverse outcomes [27,28,29] except for mortality in one study [28]. Concerning susceptibility to COVID-19, nine studies [26,27,28, 34, 37,38,39, 46] reported on this outcome; six of these studies reported a significant association between having PD and the risk for COVID-19 infection, [24, 26, 34, 37, 38, 46] whereas the other three studies [27, 28, 39] didnā€™t confirm such results (Table 2).

Table 2 Summary of the main outcomes

Meta-analysis results

COVID-19 outcomes in PD versus healthy periodontium patients:

The pooled data showed a positive significant association between PD and the risk of adverse COVID-19 outcomes (Figs.Ā 2, 3 andĀ 4). Compared to patients with healthy periodontium, patients with PD showed a significantly higher risk of severe symptoms (ORā€‰=ā€‰6.95, 95% CI: 2.24, 21.56, I2ā€‰=ā€‰92%, random-effect; Pā€‰=ā€‰0.0008)(Fig.Ā 2), ICU admission (ORā€‰=ā€‰3.15, 95% CI: 2.07, 4.79, I2ā€‰=ā€‰0.00%, fixed-effect; Pā€‰=ā€‰0.0001) (Fig.Ā 3), and mortality (ORā€‰=ā€‰1.92, 95% CI: 0.70, 5.32, I2ā€‰=ā€‰57%, random-effect; Pā€‰=ā€‰0.21) (Fig.Ā 4).

Fig. 2
figure 2

Meta-analysis of the association between periodontal disease (PD) and severe COVID-19 symptoms

Fig. 3
figure 3

Meta-analysis of the association between periodontal disease (PD) and ICU admissions

Fig. 4
figure 4

Meta-analysis of the association between periodontal disease (PD) and mortality

COVID-19 outcomes by severity of PD (severe PD versus mild PD)

The results revealed a positive significant association between the severity of PD and severity of COVID-19 outcomes (Figs.Ā 5, 6 andĀ 7): severe symptoms (ORā€‰=ā€‰3.25, 95% CI: 1.23, 8.59, I2ā€‰=ā€‰87%, random-effect; Pā€‰=ā€‰0.02) (Fig.Ā 5); ICU admission (ORā€‰=ā€‰3.38, 95% CI: 1.82, 6.26, I2ā€‰=ā€‰0.00%, fixed-effect; Pā€‰=ā€‰0.0001) (Fig.Ā 6), and mortality rate (ORā€‰=ā€‰5.35, 95% CI: 2.75, 10.42, I2ā€‰=ā€‰48%, fixed-effect; Pā€‰=ā€‰0.00001) (Fig.Ā 7).

Fig. 5
figure 5

Meta-analysis of the association between severe periodontal disease (PD) and COVID-19 symptoms

Fig. 6
figure 6

Meta-analysis of the association between severe periodontal disease (PD) and ICU admission

Fig. 7
figure 7

Meta-analysis of the association between severe periodontal disease (PD) and mortality rate

Risk of COVID-19 in PD patients versus healthy periodontium patients:

The pooled three studies revealed a higher risk of COVID-19 infection in periodontitis patients (ORā€‰=ā€‰1.58, 95% CI: 0.89, 2.79, I2ā€‰=ā€‰57%, Pā€‰=ā€‰0.12), although the result was not statistically significant (Fig.Ā 8).

Fig. 8
figure 8

Meta-analysis of COVID-19 risk in relation to periodontal health status (PD vs. healthy)

Publication bias

The funnel plots for publication bias of the include studies for all categories are presented in the Supplementary file 2. Generally, there was not a noticeable publication bias among the studies, except Fig.Ā 1Ā in the Supplementary file 2 which showed slight publication bias for the association between periodontal disease (PD) and severe COVID-19 symptoms.

Quality assessment

The results of the quality assessment- based on NOS- are presented in Table 3. Overall, the included studies revealed relatively good quality ranging from five to nine stars. Fourteen studies [22,23,24,25, 27,28,29, 34, 36,37,38, 40, 43,44,45] were of high quality, while seven studies were of moderate quality [33, 35, 39, 41, 42, 46, 47]. The most frequent methodological shortcomings were related to the self-report ascertainment of the exposure and bias in selection of cases/controls (Table 3).

Table 3 NOS-based quality analysis of the included studies

Discussion

Medical literature has linked PD to the risk and severity of COVID-19. Hence, the present systematic review and meta-analysis sought to answer the following focused question: Does PD influence the risk and severity of COVID-19? Qualitatively, most of the included studies reported significant association between PD and COVID-19 severity. However, three studies [27,28,29] failed to replicate these results. Quantitatively the pooled data found a significant positive association between PD and the risk and adverse outcomes of COVID-19 such as severe symptoms, ICU admission. Additionally, severe PD was significantly associated with higher risk of severe COVID-19 symptoms (Pā€‰=ā€‰0.02), ICU admission (Pā€‰=ā€‰0.0001), and mortality rate (Pā€‰=ā€‰0.00001) compared to mild PD. Indeed, the results revealed that patients with PD have significantly 54% higher risk to getting COVID-19 infection. However, these findings should be interpreted with caution owing to the heterogeneity among the included studies as well as some methodological limitations, discussed in the following sections.

The findings of the present systematic review support the results of previous systematic reviews [30, 31]. Nevertheless, although the results of the current study are interesting, the mechanism(s) by which periodontitis aggravate(s) COVID-19 adverse outcomes still unclear so far. However, many theories have been suggested, and deserve discussion. With regard to one of the key findings of the current study: association of PD and COVID-19 adverse outcomes, one possible explanation is related to the expression of angiotensin converting enzyme 2 (the well- known receptor for SARS-CoV-2) by the inspired periopathogenes. This subsequently leads to production of inflammatory cytokines such as IL-6 and IL-8 in the lower respiratory tract, thus aggravating the response [48]. Further, periopathogenes have been reported to enhance the virulence of SARS-CoV-2 by cleaving its S glycoproteins, a matter that exacerbates COVID-19 complications [49]. Of utmost important, the chronic inflammatory nature of periodontitis may play a role through triggering systemic inflammation, which aggravates the inflammatory response in context of many disease processes, and COVID-19 wouldnā€™t be an exception. A recent study reported existence of periopathogenes in the metagenome of patients severely infected with SARS-CoV-2: Mainly high reads for Prevotella (493 reads), Staphylococcus (1,659 reads) and Fusobacterium (463 reads) were discovered [50]. Indeed, the potential role of PD in pulmonary infections (and diseases) has long been investigated and well documented in the literature [16, 51,52,53]. Mounting evidence from systematic reviews and meta-analyses found a significant association between PD and exacerbation of respiratory conditions, mainly pneumonia and COPD [14, 17].

The significant association between PD and the risk of COVID-19 is another key and pivotal finding of the current study: patients with PD were 54% at higher risk of COVID-19 acquisition than people with healthy periodontium. Essentially, the oral cavity, including gingival pocket epithelium, has been reported to be potentially high risk for SARS-CoV-2 infectious susceptibility, mediated by expression of angiotensin converting enzyme 2 [54, 55]. These results might be explained by the role of periopathogenic bacteria in initiating the expression of angiotensin converting enzyme, as already discussed above. A very recent evidence suggests that periodontal pockets and decayed teeth serve as reservoirs for SARS-CoV-2, making people more prone to COVID-19 [56]. In addition to being hiding areas, where the antibacterial action of the saliva and mouth rinses is not effective, the periodontally involved pockets have higher surface area than that of normal gingival sulcus, providing more opportunities for SARS-CoV-2 to bind and eventually infect more enzyme-expressing cells, in addition to acting as reservoirs for continuing infection, or recurring, or complicating the current infection leading to a more severe disease. However, these are still hypotheses and more research are required to elucidate these phenomena.

Worthy to note that the positive association of PD with the outcomes of COVID-19 was supported by all of the included studies except two studies by Larvin et al., which failed to do so [27, 28]. It must be acknowledged that these two studies involved relatively large sample sizes of COVID-19 patients. However, the exposure (periodontal status) was self-reported, a matter which raises a lot of doubts and reduces reliability of these two studies. Obviously, it is a clear shortcoming, and therefore the results might have not accurately reflected the periodontal status of the participants, and thus might have biased the results. Apart from the fact that the number of present and/or the missing teeth can be self-reported to a large extent of reliability, the other periodontal health outcomes and parameters cannot be reported by the patients precisely [57] . This, in turn, may explain the different results obtained by these two studies, a matter that must be acknowledged too. By contrast, except for Kamel et al. study, all other studies, which reported positive association of PD with the outcomes of COVID-19 ascertained the periodontal parameters objectively, either clinically or using radiographs.

Undoubtedly, the quality of the individual studies is a very determining factor that influences the quality of the overall evidence of any meta-analysis [58]. For this purpose, two reviewers evaluated independently the quality of all included studies using NOS, a very valid risk assessment tool. The results revealed relatively good quality of the included studies. Selection bias and self-reporting of the exposure (periodontal parameters) were the most frequently shortcomings, which cause biased results: recapitulating and reminding Larvin et al. studies mentioned above.

The present systematic review has many points that add to its strength and should be recognized. First, the study included a good number of studies with a relatively large sample size. Second, the studies were conducted in different geographical areas representing the world and thus substantiating its external validity. However, there are few limitations that should be highlighted. The main limitation is the heterogeneity among the included studies in many respects including: study design, the assessed periodontal parameters (exposure), COVID-19 parameters (outcome), setting of the included patients (hospitalized vs non-hospitalized patients), age of the participants, and many other confounders. The differences in methods of measurements of periodontal parameters represent a marked heterogeneity, being self-reported in a few studies, using radiographs in some studies, and clinical examination in the other studies. In particular, the self-reporting of periodontal status is an evident drawback of the present study that might have caused bias in the results. Furthermore, missing of some of the numerical data was an obvious obstacle that hindered including all studies in the quantitative analysis.

Conclusion

In conclusion, the present systematic review and meta-analysis suggests a significant association between poor periodontal health and poor COVID-19 outcomes. However, the results should be interpreted with caution given the marked heterogeneity across the included studies along with some methodological limitations in some of these studies. Hence, further large-scale prospective cohort studies with standardized methodologies are highly required to further elucidate the potential association between periodontal diseases and the risk of poor COVID-19 outcomes.

Availability of data and materials

All data generated or analyzed during this study are included in this published article.

Abbreviations

COVID-19:

Coronavirus Disease 2019

PD:

Periodontitis

ICU:

Intensive Care Unit

CI:

Confidence Interval

NOS:

Newcastle Ottawa Scale

OR:

Odds Ratio

References

  1. DeMartino JK, Swallow E, Goldschmidt D, Yang K, Viola M, Radtke T, Kirson N. Direct health care costs associated with COVID-19 in the United States. J Manag Care Spec Pharm. 2022;28(9):936ā€“47.

  2. Prezant DJ, Lancet EA, Zeig-Owens R, Lai PH, Appel D, Webber MP, Braun J, Hall CB, Asaeda G, Kaufman B, et al. System impacts of the COVID-19 pandemic on New York Cityā€™s emergency medical services. J Am Coll Emerg Physicians Open. 2020;1(6):1205ā€“13.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  3. Al-Maweri SA, Halboub E, Warnakulasuriya S. Impact of COVID-19 on the early detection of oral cancer: A special emphasis on high risk populations. Oral Oncol. 2020;106: 104760.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  4. Zhou F, Yu T, Du R, Fan G, Liu Y, Liu Z, Xiang J, Wang Y, Song B, Gu X, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet. 2020;395(10229):1054ā€“62.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  5. Richardson S, Hirsch JS, Narasimhan M, Crawford JM, McGinn T, Davidson KW, Barnaby DP, Becker LB, Chelico JD, Cohen SL, et al. Presenting Characteristics, Comorbidities, and Outcomes Among 5700 Patients Hospitalized With COVID-19 in the New York City Area. JAMA. 2020;323(20):2052ā€“9.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  6. Pujhari S, Paul S, Ahluwalia J, Rasgon JL. Clotting disorder in severe acute respiratory syndrome coronavirus 2. Rev Med Virol. 2021;31(3): e2177.

    PubMedĀ  Google ScholarĀ 

  7. Sinha P, Matthay MA, Calfee CS. Is a ā€œCytokine Stormā€ Relevant to COVID-19? JAMA Intern Med. 2020;180(9):1152ā€“4.

    PubMedĀ  Google ScholarĀ 

  8. Liu J, Virani SS, Alam M, Denktas AE, Hamzeh I, Khalid U. Coronavirus disease-19 and cardiovascular disease: A risk factor or a risk marker? Rev Med Virol. 2021;31(3): e2172.

    PubMedĀ  Google ScholarĀ 

  9. Papapanou PN, Sanz M, Buduneli N, Dietrich T, Feres M, Fine DH, Flemmig TF, Garcia R, Giannobile WV, Graziani F, et al. Periodontitis: Consensus report of workgroup 2 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. J Clin Periodontol. 2018;45(Suppl 20):S162-s170.

    PubMedĀ  Google ScholarĀ 

  10. Petersen PE, Ogawa H. The global burden of periodontal disease: towards integration with chronic disease prevention and control. Periodontol 2000. 2012, 60(1):15ā€“39.

  11. Al-Maweri SA, Ibraheem WI, Al-Akā€™hali MS, Shamala A, Halboub E, Alhajj MN. Association of periodontitis and tooth loss with liver cancer: A systematic review. Crit Rev Oncol Hematol. 2021;159: 103221.

    PubMedĀ  Google ScholarĀ 

  12. Alakhali MS, Al-Maweri SA, Al-Shamiri HM, Al-Haddad K, Halboub E. The potential association between periodontitis and non-alcoholic fatty liver disease: a systematic review. Clin Oral Investig. 2018;22(9):2965ā€“74.

    PubMedĀ  Google ScholarĀ 

  13. Dhaifullah E, Al-Maweri SA, Koppolu P, Elkhtat E, Mostafa D, Mahgoub M. Body mass index and periodontal health status among young Saudi adults: a cross-sectional study. Ann Saudi Med. 2019;39(6):433ā€“40.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  14. Kelly N, Winning L, Irwin C, Lundy FT, Linden D, McGarvey L, Linden GJ, El Karim IA. Periodontal status and chronic obstructive pulmonary disease (COPD) exacerbations: a systematic review. BMC Oral Health. 2021;21(1):425.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  15. Sanz M, Marco Del Castillo A, Jepsen S, Gonzalez-Juanatey JR, Dā€™Aiuto F, Bouchard P, Chapple I, Dietrich T, Gotsman I, Graziani F, et al. Periodontitis and cardiovascular diseases: Consensus report. J Clin Periodontol. 2020;47(3):268ā€“88.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  16. Scannapieco FA, Bush RB, Paju S. Associations between periodontal disease and risk for nosocomial bacterial pneumonia and chronic obstructive pulmonary disease. A systematic review Ann Periodontol. 2003;8(1):54ā€“69.

    PubMedĀ  Google ScholarĀ 

  17. Wu Z, Xiao C, Chen F, Wang Y, Guo Z. Pulmonary disease and periodontal health: a meta-analysis. Sleep Breath. 2022.

  18. Hajishengallis G. Periodontitis: from microbial immune subversion to systemic inflammation. Nat Rev Immunol. 2015;15(1):30ā€“44.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  19. Tamimi F, Altigani S, Sanz M. Periodontitis and coronavirus disease 2019. Periodontol 2000. 2022, 89(1):207ā€“214.

  20. Sahni V, Gupta S. COVID-19 & Periodontitis: The cytokine connection. Med Hypotheses. 2020;144: 109908.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  21. Herrera D, Serrano J, RoldĆ”n S, Sanz M. Is the oral cavity relevant in SARS-CoV-2 pandemic? Clin Oral Invest. 2020;24(8):2925ā€“30.

    Google ScholarĀ 

  22. Marouf N, Cai W, Said KN, Daas H, Diab H, Chinta VR, Hssain AA, Nicolau B, Sanz M, Tamimi F. Association between periodontitis and severity of COVID-19 infection: a case-control study. J Clin Periodontol. 2021;48(4):483ā€“91.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  23. Gupta S, Mohindra R, Singla M, Khera S, Sahni V, Kanta P, Soni RK, Kumar A, Gauba K, Goyal K, et al. The clinical association between Periodontitis and COVID-19. Clin Oral Invest. 2022;26(2):1361ā€“74.

    Google ScholarĀ 

  24. Wadhwa S, Dave S, Daily ML, Nardone A, Li R, Rosario J, Cantos A, Shah J, Lu HH, McMahon DJ, et al. The role of oral health in the acquisition and severity of SARS-CoV-2: a retrospective chart review. Saudi Dent J. 2022;34(7):596ā€“603.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  25. Said KN, Al-Momani AM, Almaseeh JA, Marouf N, Shatta A, Al-Abdulla J, Alaji S, Daas H, Tharupeedikayil SS, Chinta VR, et al. Association of periodontal therapy, with inflammatory biomarkers and complications in COVID-19 patients: a case control study. Clin Oral Investig. 2022;26(11):6721ā€“32.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  26. Wang Y, Deng H, Pan Y, Jin L, Hu R, Lu Y, Deng W, Sun W, Chen C, Shen X, et al. Periodontal disease increases the host susceptibility to COVID-19 and its severity: a Mendelian randomization study. J Transl Med. 2021;19(1):528.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  27. Larvin H, Wilmott S, Kang J, Aggarwal VR, Pavitt S, Wu J. Additive Effect of Periodontal Disease and Obesity on COVID-19 Outcomes. J Dent Res. 2021;100(11):1228ā€“35.

    PubMedĀ  Google ScholarĀ 

  28. Larvin H, Wilmott S, Wu J, Kang J. The Impact of Periodontal Disease on Hospital Admission and Mortality During COVID-19 Pandemic. Front Med (Lausanne). 2020;7: 604980.

    PubMedĀ  Google ScholarĀ 

  29. Donders H, van der Sleen J, Kleinbergen Y, Su N, de Lange J, Loos B. Alveolar bone loss and tooth loss are associated with COVID-19 severity but are not independent risk factors. An explorative study. J Oral Maxillofac Surg. 2022, 5:100223.

  30. Espinoza-Espinoza DAK, Dulanto-Vargas JA, CĆ”ceres-LaTorre OA, Lamas-Castillo FE, Flores-Mir C, Cervantes-Ganoza LA, LĆ³pez-Gurreonero C, Ladera-CastaƱeda MI, Cayo-Rojas CF. Association between periodontal disease and the risk of COVID-19 complications and mortality: a systematic review. J Int Soc Prev Community Dent. 2021;11(6):626ā€“38.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  31. Baima G, Marruganti C, Sanz M, Aimetti M, Romandini M. Periodontitis and COVID-19: biological mechanisms and meta-analyses of epidemiological evidence. J Dent Res. 2022;101(12):1430ā€“40.

    PubMedĀ  Google ScholarĀ 

  32. Stang A. Critical evaluation of the Newcastle-Ottawa scale for the assessment of the quality of nonrandomized studies in meta-analyses. Eur J Epidemiol. 2010;25(9):603ā€“5.

    PubMedĀ  Google ScholarĀ 

  33. Alnomay N, Alolayan L, Aljohani R, Almashouf R, Alharbi G. Association between periodontitis and COVID-19 severity in a tertiary hospital: A retrospective cohort study. Saudi Dent J. 2022;34(7):623ā€“8.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  34. Anand PS, Jadhav P, Kamath KP, Kumar SR, Vijayalaxmi S, Anil S. A case-control study on the association between periodontitis and coronavirus disease (COVID-19). J Periodontol. 2022;93(4):584ā€“90.

    PubMedĀ  Google ScholarĀ 

  35. Bemquerer LM, Oliveira SR, de Arruda JAA, Costa FPD, Miguita L, Bemquerer ALM, et al. Clinical, immunological, and microbiological analysis of the association between periodontitis and COVID-19: a case-control study. Odontology. 2023. p. 1ā€“13.

  36. Costa CA, Vilela ACS, Oliveira SA, Gomes TD, Andrade AAC, Leles CR, Costa NL. Poor oral health status and adverse COVID-19 outcomes: a preliminary study in hospitalized patients. J Periodontol. 2022;93(12):1889ā€“901.

  37. Guardado-Luevanos I, Bologna-Molina R, Zepeda-NuƱo JS, Isiordia-Espinoza M, Molina-Frechero N, GonzĆ”lez-GonzĆ”lez R, PĆ©rez-PĆ©rez M, LĆ³pez-VerdĆ­n S. Self-Reported Periodontal Disease and Its Association with SARS-CoV-2 Infection. Int J Environ Res Public Health. 2022;19(16):10306.

  38. Gujar D, Joshi C, Pandya DJ, Nayak K, Shafiuddin M, Sameerudeen S, Mahajan A. Exploring the correlation between covid-19 and periodontal diseases-An original research. Eur J Mol Clin Med. 2022;9(7):8707ā€“12.

    Google ScholarĀ 

  39. Holt H, Talaei M, Greenig M, Zenner D, Symons J, Relton C, et al. Risk factors for developing COVID-19: a population-based longitudinal study (COVIDENCE UK). Thorax. 2022;77(9):900ā€“12.

  40. Kalsi R, Ahmad Z, Siddharth M, Vandana K, Arora S, Saurav K. Correlation of COVID-19 with severity of periodontitis-A clinical and biochemical study. Indian J Dent Res. 2022;33(3):307ā€“12.

    PubMedĀ  Google ScholarĀ 

  41. Kamel AHM, Basuoni A, Salem ZA, AbuBakr N. The impact of oral health status on COVID-19 severity, recovery period and C-reactive protein values. Br Dent J. 2021. p. 1ā€“7.

  42. Kaur A, Sandhu HS, Sarwal A, Bhagat S, Dodwad R, Singh G, Gambhir RS. Assessment of correlation of COVID-19 infection and periodontitis-A comparative study. J Family Med Prim Care. 2022;11(5):1913ā€“7.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  43. Koppolu P, Genady EM, Albdeirat LM, Sebai FA, Alrashdi DM, Lingam AS. FA RA, Al-Khalifa FI, Abdelrahim RK: Association between severity of COVID-19, Periodontal health and disease in Riyadh subpopulation. Int J Mycobacteriol. 2023;12(1):33ā€“7.

    PubMedĀ  Google ScholarĀ 

  44. Mishra S, Gupta V, Rahman W, Gazala M, Anil S. Association between Periodontitis and COVID-19 Based on Severity Scores of HRCT Chest Scans. Dent J. 2022;10(6):106.

    Google ScholarĀ 

  45. Poyato-Borrego M, LeĆ³n-LĆ³pez M, MartĆ­n-GonzĆ”lez J, Cisneros-Herreros JM, Cabanillas-Balsera D, Segura-Egea JJ. Endodontic variables in patients with SARS-CoV-2 infection (COVID-19) in relation to the severity of the disease. Med Oral Patol Oral Cir Bucal. 2023;28(4):e355ā€“e361.

  46. Sari A, Dikmen NK, Nibali L. Association between periodontal diseases and COVID-19 infection: a case-control study with a longitudinal arm. Odontology. 2023. p. 1ā€“9.

  47. Sirin DA, Ozcelik F. The relationship between COVID-19 and the dental damage stage determined by radiological examination. Oral Radiol. 2021;37(4):600ā€“9.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  48. Takahashi Y, Watanabe N, Kamio N, Kobayashi R, Iinuma T, Imai K. Aspiration of periodontopathic bacteria due to poor oral hygiene potentially contributes to the aggravation of COVID-19. J Oral Sci. 2020;63(1):1ā€“3.

    PubMedĀ  Google ScholarĀ 

  49. MadapusiBalaji T, Varadarajan S, Rao USV, Raj AT, Patil S, Arakeri G, Brennan PA. Oral cancer and periodontal disease increase the risk of COVID 19? A mechanism mediated through furin and cathepsin overexpression. Med Hypotheses. 2020;144: 109936.

    Google ScholarĀ 

  50. Chakraborty S. Metagenome of SARS-Cov2 patients in Shenzhen with travel to Wuhan shows a wide range of species-Lautropia, Cutibacterium, Haemophilus being most abundant-and Campylobacter explaining diarrhea. Available at: https://osf.io/jegwq,Ā https://doi.org/10.31219/osf.io/jegwq. Accessed June 2023.

  51. Gomes-Filho IS, Cruz SSD, Trindade SC, Passos-Soares JS, Carvalho-Filho PC, Figueiredo A, Lyrio AO, Hintz AM, Pereira MG, Scannapieco F. Periodontitis and respiratory diseases: a systematic review with meta-analysis. Oral Dis. 2020;26(2):439ā€“46.

    PubMedĀ  Google ScholarĀ 

  52. Kim SJ, Kim K, Choi S, Chang J, Kim SM, Park SM, Cho HJ. Chronic periodontitis and community-acquired pneumonia: a population-based cohort study. BMC Pulm Med. 2019;19(1):268.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  53. Hata R, Noguchi S, Kawanami T, Yamasaki K, Akata K, Ikegami H, Fukuda K, Hirashima S, Miyawaki A, Fujino Y, et al. Poor oral hygiene is associated with the detection of obligate anaerobes in pneumonia. J Periodontol. 2020;91(1):65ā€“73.

    PubMedĀ  Google ScholarĀ 

  54. Sakaguchi W, Kubota N, Shimizu T, Saruta J, Fuchida S, Kawata A, Yamamoto Y, Sugimoto M, Yakeishi M, Tsukinoki K. Existence of SARS-CoV-2 Entry Molecules in the Oral Cavity. Int J Mol Sci. 2020;21(17):6000.

  55. Xu H, Zhong L, Deng J, Peng J, Dan H, Zeng X, Li T, Chen Q. High expression of ACE2 receptor of 2019-nCoV on the epithelial cells of oral mucosa. Int J Oral Sci. 2020;12(1):8.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  56. Natto ZS, Afeef M, Bakhrebah MA, Ashi H, Alzahrani KA, Alhetheel AF, Fletcher HM. Can periodontal pockets and caries lesions act as reservoirs for coronavirus? Mol Oral Microbiol. 2022;37(2):77ā€“80.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

  57. Sekundo C, Stock C, JĆ¼rges H, Listl S. Patientsā€™ self-reported measures of oral health-A validation study on basis of oral health questions used in a large multi-country survey for populations aged 50. Gerodontology. 2019;36(2):171ā€“9.

    PubMedĀ  Google ScholarĀ 

  58. Metelli S, Chaimani A. Challenges in meta-analyses with observational studies. Evid Based Ment Health. 2020;23(2):83ā€“7.

    PubMed CentralĀ  PubMedĀ  Google ScholarĀ 

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Acknowledgements

Open Access funding was provided by Qatar National Library.

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Sadeq Al-Maweri: study concept, search strategy, drafting the manuscript; Mohammed Nasser Alhajj: data extraction, quality appraisal, data analysis, drafting the manuscript; Esam Halboub: concept of the study, critically revised and edited the paper; Faleh Tamimi: data extraction, quality appraisal, drafting the manuscript; Nosizana Mohd Salleh: concept of the study, critically revised and edited the paper; Mohammed Sultan Al-Akā€™hali: concept of the study, critically revised and edited the paper; Saba Kassim, Saleem Abdulrab, Lamyia Anweigi, and Marwan Mansoor Ali Mohammed, data curation, critically revised and edited the paper. All authors approved the final version.

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Correspondence to Sadeq Ali Al-Maweri.

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Supplementary Information

Additional file 1:Ā 

Table S1. Databases. Applied search strategy, and numbers of retrieved studies. Table S2. List of excluded studies and reason for exclusion.Ā 

Additional file 2:

Figure S1. Funnel plot for the included studies of the association between periodontal disease (PD) and severe COVID-19 symptoms. Figure 2. Funnel plot for the included studies of the association between periodontal disease (PD) and ICU admissions. Figure S3. Funnel plot for the included studies of the association between periodontal disease (PD) and mortality. Figure S4. Funnel plot for the included studies of the association between severe periodontal disease (PD) and COVID-19 symptoms. Figure S5. Funnel plot for the included studies of the association between severe periodontal disease (PD) and ICU admission. Figure S6. Funnel plot for the included studies of the association between severe periodontal disease (PD) and mortality rate. Figure S7. Funnel plot for the included studies of COVID-19 risk in relation to periodontal health status (PD vs. healthy).

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Al-Maweri, S.A., Alhajj, M.N., Halboub, E. et al. The impact of periodontal disease on the clinical outcomes of COVID-19: A systematic review and meta-analysis. BMC Oral Health 23, 658 (2023). https://doi.org/10.1186/s12903-023-03378-0

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