Effectiveness of mouthwashes on reducing SARS-CoV-2 viral load in oral cavity: a systematic review and meta-analysis

Abstract

Background The risk of SARS-COV-2 transmission is relatively high during dental procedures. A study was conducted to investigate the effects of mouthwashes on SARS-COV-2 viral load reduction in the oral cavity. Methods A systematic search was performed in PubMed, EMBASE, Scopus, Web of Science, and Cochrane library for relevant studies up to 20 July, 2022. Randomized and non-randomized clinical trial and quasi-experimental studies evaluating patients with Covid-19 infection (patients) who used mouthwashes (intervention) compared to the same patients before using the mouthwash (comparison) for reducing the SARS-COV-2 load or increasing the cycle threshold (Ct) value (outcome) were searched according to PICO components. Three independent reviewers conducted literature screening and data extraction. The Modified Downs and Black checklist was used for quality assessment. A meta-analysis was performed with a random effects model in the Revman 5.4.1software using the mean difference (MD) of cycle threshold (Ct) values. Results Of 1653 articles, 9 with a high methodological quality were included. A meta-analysis indicated that 1% Povidone-iodine (PVP-I) was an effective mouthwash for reducing the SARS-COV-2 viral load [MD 3.61 (95% confidence interval 1.03, 6.19)]. Cetylpyridinium chloride (CPC) [MD 0.61 (95% confidence interval -1.03, 2.25)] and Chlorhexidine gluconate (CHX) [MD -0.04 95% confidence interval (-1.20, 1.12)] were not effective against SARS-COV-2. Conclusion Using mouthwashes containing PVP-I may be recommended for reducing the SARS-COV-2 viral load in the oral cavity of patients before and during dental procedures, while the evidence is not sufficient for such effects for CPC and CHX-containing mouthwashes.

Efficacy of different mouthwashes against COVID-19: A systematic review and network meta-analysis

“…PVP-I was confirmed to be effective against SARS-CoV-2 not only after 5 min from rinsing, but also after hours (i.e. 1 h, 2 h, 3 h and 6 h after rinsing) [17] . In the same meta-analysis, CHX and CPC were found not to be effective in reducing SARS-COV-2 viral load.…”

“…Furthermore, owing to the high heterogeneity and lack of standard deviation values, no meta-analysis could be performed for in vitro studies. In a recent meta-analysis the effect of PVP-I, CHX and CPC was assessed [17] . Contrary to our quantitative evaluation, the analysis considered not only the immediate but also the long-lasting effect of the mouthwashes.…”

“…Furthermore, it is not clear whether and to which extent these interventions are effective in the prevention of viral spread in dental setting. Despite numerous reviews have been published so far on the topic [15] , [16] , [17] , to the best of the authors’ knowledge, this is the first systematic review and meta-analysis aiming to investigate, both in clinical and in vitro studies, the effectiveness of antiseptic mouthwashes and rinsing protocols in reducing SARS-CoV-2 load.…”

Oral mouthwashes for asymptomatic to mildly symptomatic adults with COVID-19 and salivary viral load: a randomized, placebo-controlled, open-label clinical trial

“…A recent randomized, double-blind, controlled clinical trial has also indicated that SARS-CoV-2 RNA copy numbers were stable for up to 60 min after the use of 0.05% CPC mouthwash [ 16 ]. Recent systematic reviews have also shown that using 0.075% CPC-containing mouthwashes may not be effective in reducing SARS-CoV-2 viral load [ 40 , 41 ]. This might be due to the fact that the antiviral effects of CPC against SARS-CoV-2 are the result of lipid membrane disruption in the viral envelope, without an effect on viral RNA integrity [ 42 – 44 ].…”