Comparative evaluation of bacterial colonization on removable dental prostheses in patients with COVID-19: A clinical study

STATEMENT OF PROBLEM: In the outbreak of COVID-19, coinfections and even superinfections in the background of SARS-CoV-2 viral infection have been reported. Such bacterial and fungal strains may be colonized in different tissues and organs, including the oral cavity. Whether infection with COVID-19 could increase colonization of different bacterial strains on removable dental prostheses is unclear. PURPOSE: The purpose of this clinical study was to compare bacterial colonization on removable dental prostheses in patients with COVID-19, before versus after diagnosis. MATERIAL AND METHODS: Two sex- and age-matched groups of complete-denture-wearing participants (N=60) with and without a positive diagnosis for COVID-19 were enrolled in the study. Swabs were used at 2 different time intervals to sample areas of the dentures, which were then cultured and the colony smears Gram stained. A statistical analysis was conducted by using the Mann-Whitney U test (α=.05). RESULTS: Streptococcus species (93.3% versus 40.0%, P=.047) and Klebsiella pneumonia (46.7% versus 13.4%, P=.036) were detected more frequently in the COVID-19-positive group. CONCLUSIONS: Higher rates of bacterial colonization, especially with Streptococcus species and Klebsiella pneumonia, were detected on removable dental prostheses after COVID-19 infection.