Can periodontal pockets and caries lesions act as reservoirs for coronavirus?

The periodontal pocket and likely caries lesions may act as a reservoir and source of dissemination and development of systemic infections. While periodontal pockets have been found to harbor several viral species, there is no information on its ability to serve as a reservoir for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We have used a real-time polymerase chain reaction (RT-PCR) approach to evaluate SARS-CoV-2 in periodontal pockets and cavitated caries lesions in a cross-sectional study of 72 participants who were divided into six groups: symptomatic positive COVID-19 cases with periodontal pockets, symptomatic positive with cavitated caries lesions, asymptomatic positive with periodontal pockets, asymptomatic positive with cavitated caries lesions, positive control, and negative control. A total of 180 samples were interrogated by RT-PCR to amplify the SARS-CoV-2 E and S genes. SARS-CoV-2 was present in 41.7% of symptomatic positive COVID-19 cases with periodontal pockets and 16.7% of symptomatic positive with cavitated caries lesions. The mean Ct value of E and S genes in periodontal pockets patients were 36.06±0.46 and 30.06±6.73, respectively, and the mean Ct value for both genes in caries lesions patients were 35.73±4.14, and 34.78±1.93, respectively. The sensitivity, specificity, and accuracy to detect SARS-CoV-2 among periodontal pockets were 20.8% (95% CI 7.13-42.15), 100% (95% CI 73.54-100.0), and 47.2% (95% CI 30.22-64.51), respectively. Among cavitated caries lesions patients, they were 8.3% (95% CI 1.03-27.0), 100% (95% CI 73.54-100.0), and 38.9% (95% CI 23.14-56.54), respectively. SARS-CoV-2 can be detected in periodontal pockets and caries lesions, and these sites may act as reservoirs for the virus. However, the sensitivity of SARS-CoV-2 detection is low compared with other methods. To our knowledge, this report is the first to investigate the relationship between SARS-CoV-2 and periodontal pockets and caries.