In vivoevaluation of the virucidal efficacy of Chlorhexidine and Povidone-iodine mouthwashes against salivary SARS-CoV-2

Background The oral cavity is potentially high-risk transmitter of COVID-19. Antimicrobial mouthrinses are used in many clinical pre procedural situations for prophylactic purposes. An evident-based investigation for an effective mouthwash solution against salivary SARS-CoV-2 is urgently required for the exposure reduction during dental procedures. Aims This study aimed to evaluate in vivo virucidal efficacy of 2 mouthwashes: 1% Povidoneiodine and 0.2% Chlorhexidine as a dental preprocedural oral disinfection against salivary SARS-CoV-2. Materials and Methods In this randomized-controlled clinical trial, studied group comprised laboratory-confirmed COVID-19 positive patients through nasopharyngeal swabs. Participants were divided into 3 groups. For 30 seconds, group A gargled with 1% Povidone-iodine, group B mouthrinsed with 0.2% Chlorhexidine and control group C mouthrinsed with distilled water. Saliva samples were collected before and 5 minutes after mouthwash. SARS-CoV-2 rRT-PCR was then performed for each sample. Evaluation of the efficacy was based on difference in Ct value. The analysis of data was carried out using GraphPad Prism version 5 for Windows. Paired t test and unpaired t test were used. A probability value of less than 0.05 was regarded as statistically significant. Results Sixty-one compliant participants (36 female and 25 male) with a mean age 45.3 ± 16.7 years-old were enrolled. A significant mean Ct value difference ( p < 0.0001) between the paired samples in group A (n = 25) and also in group B (n = 27) ( p < 0.0001) was found. In contrast, no significant difference ( p = 0.566) existed before and after the experiment in the control group C (n = 9). Moreover, a significant difference was noted between the delta Ct of distilled water wash and each of the 2 solutions 1 % Povidone-iodine ( p = 0.012) and Chlorhexidine 0.2% ( p = 0.0024). No significant difference was found between the delta Ct of patients using 1% Povidone-iodine and Chlorhexidine 0.2% solutions ( p = 0.24). Conclusion Chlorhexidine 0.2% and 1% Povidone-iodine oral solutions are effective preprocedural mouthwashes against salivary SARS-COV-2 in dental treatments. Their use as a preventive strategy to reduce the spread of COVID-19 during dental practice should be systematically implemented.