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Updated: Aug 19, 2026

Inducing Apical Periodontitis in Mice
Published on: August 6, 2019
COVID-19 Severity in Patients With Apical Periodontitis: A Case Control Study
Nadya Marouf1, Raidan Ba-Hattab2, Fatima Al-Sheeb1
1Division of Endodontics, Department of Dentistry, Oral Health Institute, Hamad Medical Corporation, Doha, Qatar; College of Dental Medicine, QU Health, Qatar University, Doha, Qatar; Hamad Dental Center, Hamad Medical Corporation, Doha, Qatar.
Objectives:
Apical periodontitis (AP) has been associated with systemic inflammatory biomarkers that have also been associated with COVID-19 severity. This study was designed to test the hypothesis that the presence of apical periodontitis could be associated with increased risk of COVID-19 complications.
Methods:
A case control study (N = 949) was performed using the medical and dental records of patients diagnosed with COVID-19 in the State of Qatar between March 2020 and February 2021. Cases comprised COVID-19 patients (n = 63) who experienced complications (death, intensive care unit admissions, mechanical ventilation), and controls were COVID-19 patients (n = 886) who recovered without such complications. The presence of periapical apical periodontitis was assessed on the radiographic records taken prior to COVID-19 infection. Associations between apical periodontitis and COVID 19 complications were analysed using logistic regression models adjusted for demographic and medical factors. Blood biomarkers were assessed in both groups and compared using the Kruskal-Wallis test.
Results:
COVID-19 complications were found to be associated with the presence of apical periodontitis (adjusted odds ratio = 2.72; 95% CI, 1.30-5.68; P = .008). Blood analyses revealed that COVID-19 patients with apical periodontitis had higher levels of white blood cells and haemoglobin A1c than the patients without apical periodontitis.
Conclusions:
The presence of apical periodontitis could be associated with increased risk of COVID-19 complications.
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