Rapid In‐Vitro Inactivation of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) Using Povidone‐Iodine Oral Antiseptic Rinse

PURPOSE: To investigate the optimal contact time and concentration for viricidal activity of oral preparation of povidone‐iodine (PVP‐I) against SARS‐CoV‐2 (‘corona virus’) to mitigate the risk and transmission of the virus in the dental practice. MATERIALS AND METHODS: The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) USA‐WA1/2020 strain, virus stock was tested against oral antiseptic solutions consisting of aqueous povidone‐iodine (PVP‐I) as the sole active ingredient. The PVP‐I was tested at diluted concentrations of 0.5%, 1%, and 1.5%. Test media without any virus was added to 2 tubes of the compounds to serve as toxicity and neutralization controls. Ethanol (70%) was tested in parallel as a positive control, and water only as a negative control. The test solutions and virus were incubated at room temperature (22 ± 2 °C) for time periods of 15 and 30 seconds. The solution was then neutralized by a 1/10 dilution in minimum essential medium (MEM) 2% fetal bovine serum (FBS), 50 µg/mL gentamicin. Surviving virus from each sample was quantified by standard end‐point dilution assay and the log reduction value (LRV) of each compound compared to the negative (water) control was calculated. RESULTS: PVP‐I oral antiseptics at all tested concentrations of 0.5%, 1%, and 1.5%, completely inactivated SARS‐CoV‐2 within 15 seconds of contact. The 70% ethanol control group was unable to completely inactivate SARS‐CoV‐2 after 15 seconds of contact, but was able to inactivate the virus at 30 seconds of contact. CONCLUSIONS: PVP‐I oral antiseptic preparations rapidly inactivated SARS‐CoV‐2 virus in vitro. The viricidal activity was present at the lowest concentration of 0.5 % PVP‐I and at the lowest contact time of 15 seconds. This important finding can justify the use of preprocedural oral rinsing with PVP‐I (for patients and health care providers) may be useful as an adjunct to personal protective equipment, for dental and surgical specialties during the COVID‐19 pandemic.