Virucidal Activity of Different Mouthwashes Using a Novel Biochemical Assay

Abstract

Background: Saliva of patients with COVID-19 has a high SARS-CoV-2 viral load. The risk of spreading the virus is not insignificant, and procedures for reducing viral loads in the oral cavity have been proposed. Little research to date has been performed on the effect of mouthwashes on the SARS-CoV-2 virus, and some of their mechanisms of action remain unknown. Methods: SARS-CoV-2 positive nasopharyngeal swabs measured by RT-PCR were used for virucidal activity in a 1:1 ratio, with an incubation time of 1 min. The solutions used in this study were: iodopovidone (8 mg); * D-limonene, a terpene extracted from citrus peels (0.3%); † cetylpyridinium chloride (0.1%) (CPC); ‡ chlorhexidine gluconate (10%) (CHX); § a CPC (0.12%) and CHX (0.05%) containing formula; ** a formula containing essential oils; †† a CPC containing formula (0.07%); ‡‡ a D-limonene (0.2%) and CPC (0.05%) containing formula; §§ a solution containing sodium fluoride (0.05%) and CPC (0.075%); *** a solution containing CHX (0.12%) and; ††† a CHX (0.2%) containing formula. ‡‡‡ As a control reaction, saline solution or excipient solution (water, glycerin, citric acid, colorant, sodium citrate) was used. Conclusion: Within the limitations of this study, we can conclude that a mouthwash containing both D-limonene and CPC reduced the virucidal activity in about 6 logs (>99.999% reduction). Hence, establishing a clinical protocol for dentists is suggested, where all patients to be treated rinse pre-operatively with a mouthwash containing both D-limonene and CPC to reduce the likelihood of infection with SARS-CoV-2 for dentists. This is a relatively inexpensive way to reduce viral transmission of SARS-CoV-2 from infected individuals within the community. It is also a simple way to decrease infections from asymptomatic and pre-symptomatic patients.

Efficacy of Pre-Procedural Mouthwashes against SARS-CoV-2: A Systematic Review of Randomized Controlled Trials

“…Comparable results have been described in the literature. A study by Rodríguez-Casanovas et al [ 50 ] evaluated a commercial mouthwash containing a combination of 0.05% CPC and 0.20% D-limonene. They observed a significant reduction of about 6 logs in the viral load compared with the control.…”

Virucidal Activity of Different Mouthwashes against the Salivary Load of SARS-CoV-2: A Narrative Review

“…Similarly, Eduardo et al [ 26 ] found a significant reduction in viral load for up to 60 min after rinsing when using CPC + Zinc. A study by Rodríguez-Casanovas et al [ 21 ] evaluated a commercial mouthwash containing a combination of 0.05% CPC + 0.2% D-limonene. They observed a statistically significant reduction of about 6 logs in the viral load compared with the control.…”

Oral Antiseptics against SARS-CoV-2: A Literature Review

“…It is frequently used as a dietary supplement and as a fragrance ingredient for cosmetic products because it is considered safe [ 49 , 51 ]. Rodríguez-Casanovas et al, evaluated the virucidal activity of different mouthwashes and found that D-limonene exhibited a significant reduction in virucidal activity of around 99.99% against SARS-CoV-2, through a solution containing D-limonene (0.2%) and CPC (0.05%) [ 29 ].…”