Prophylactic Effects of Mouthwashes on COVID-19 and its Family Viruses: A Systematic Review

Background and Objectives: One of the most important ways that coronavirus disease 2019 (COVID-19) is transmitted is through respiratory droplets and contact of person to person. Angiotensin-converting enzyme 2 is one of the receptors of this virus, which is abundant in the oral cavity, especially on the epithelial cells of the tongue. By joining to its receptor in the mouth, the virus can infect an individual and transmit the disease to other individuals. Mouthwashes are among the techniques used for the improvement of oral hygiene and reduction of gingivitis and periodontitis. Moreover, some of them have antiviral and antibacterial properties. The purpose of this study was to review the articles related to effective mouthwashes against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (as the causative agent of COVID-19) and its family viruses.   Methods: This study was a quick review based on the PRISMA guidelines. The databases, such as PubMed, Scopus, Web of Science, and Google Scholar, were searched using relevant keywords. There were no search restrictions on the date, publication type, and language. Totally, 47 articles were identified in this regard, and finally considering the inclusion criteria 9 articles were extracted and examined based on the study objectives.   Results: Out of nine articles, six and two studies were performed in vitro and in vivo, respectively. The results of in vitro studies showed a positive effect of betadine mouthwash in reducing the load of coronaviruses; however, chlorhexidine had no significant effect in this regard. In two in vivo articles, researchers evaluated the effects of these two mouthwashes on SARS-CoV-2. Based on their findings, both mouthwashes had positive effects on decreasing the load of this virus.   Conclusion: The use of betadine and chlorhexidine mouthwashes results in reducing the load of SARS-CoV-2. In addition, the two mouthwashes can play a role in the prevention of this disease by the inhibition of its transmission through saliva and oral cavity.