Association between periodontitis and susceptibility to COVID-19 in a sample of adult Egyptian patients with respiratory infection symptoms: a case-control study

Introduction This case-control study aimed to determine the association between coronavirus-19 disease (COVID-19) and periodontitis in a sample of adult Egyptian patients with respiratory symptoms.Methods Patients with respiratory symptoms were recruited from the COVID-19 outpatient clinic of Qasr El-Aini Medical Hospital. Based on results of real-time reverse transcription polymerase chain reaction, patients were enrolled either as cases (COVID-19-positive) or controls (COVID-19-negative). After testing negative for the virus, or after recovery, a full clinical periodontal examination was performed, in addition to full-mouth periapical radiographs. Logistic regression model was conducted to determine the predictors for COVID-19.Results There was a statistically significant association between periodontitis stage III and IV and being recently positive for COVID-19 infection (p <0.05), while both groups showed the same prevalence of periodontitis stage I and II. Also, there was no statistically significant difference between medical history presence of hypertension and diabetes mellitus, smoking, and use of oral hygiene measures in the two groups, respectively (p >0.05). Subjects with high clinical attachment loss (CAL) measurements were 3.25-fold more prone to COVID-19 than those with low CAL values. Similarly, subjects with higher bleeding on probing (BoP)% were 1.30-fold more prone to COVID-19 than those with low BoP%.Conclusions This case-control study suggests a possible association between periodontitis severity and COVID-19 infection in a sample of adult Egyptian patients. Results of logistic regression model revealed that CAL and BoP were significant predictors of COVID-19 infection (p <0.05).