Can Mouthwash Kill Coronavirus
With UK Covid-19 cases hitting a record high in April 2022, dental teams need to remain vigilant with their infection control protocols.
In England, all domestic restrictions for the public have been removed, in line with the government’s “Living Safely with Respiratory Infections” strategy.
One control measure introduced by some practices during the pandemic has been to ask patients to rinse with mouthwash prior to treatment. But just how effective is this in helping to reduce transmission of the virus?
The case for pre-procedural mouthwash
Talk of "killing Coronavirus” with a swish of mouthwash has been around since early in the pandemic.
Over the past two years, many studies have looked into the effectiveness of specific mouthwashes in helping to decrease the risk of person-to-person transmission of SARS-CoV-2.
In April 2022 it was announced that in a small trial, researchers at Cardiff University had discovered that a 30-second rise of specific types of mouthwash could eliminate 99.9% of Covid-19 virus in saliva after one minute. After 60 minutes, 99.8% of the virus was still eliminated.
The trial, involving 27 hospital patients with PCR-confirmed Covid-19, showed mouthwash containing both Cetylpyridinium Chloride (CPC) and Isopropyl Myristate (IPM) to be the most effective. Other formulations studied seemed to have little to no effect.
The mouthwash trial was part of a larger research piece to understand the viral lipid envelope and its potential role in targeted therapeutic treatments.
Research is still at early stages and Professor David Thomas, co-author of the study, cautions that “larger clinical trials and population-based studies are [needed] to determine if oral rinses have any impact on Covid-19 transmission in practice.”
A March 2022 systematic review of trials of the use of pre-procedural mouthwashes against SARS-CoV-2 concluded that “a 30-second pre-procedural rinse of 0.5/1% PVP-I, 0.12/0.2% CHX or 0.075% CPC could be beneficial to reduce the risk of cross-infection in healthcare setting performing aerosol-generating procedures [AGPs]”.
These results together have been enough to convince some dentists to incorporate pre-procedural mouthwash with a CPC-based formula into their treatment as an additional infection control measure, particularly when undertaking AGPs.
Kent Express offers Dentyl Dual Action CPC Mouthwash, which contains both CPC and IPM, in Clove and Mint flavours.
Some doubts remain
Despite the evidence obtained so far, some experts and even some mouthwash manufacturers themselves are cautious on whether mouthwash can be an effective tool to help combat the spread of Covid-19.
“Mouthwashes may help to create an inhospitable environment for the SARS-CoV-2 virus [but] there’s no evidence to suggest it’s effective at controlling the spread of the virus”, says Rachael Zimlich, Critical Care Nurse writing for Healthline.
Johnson & Johnson, makers of Listerine Mouthwash, maintain there is a lack of evidence to support using pre-procedural mouthwashes against coronavirus at this stage:
“Although there are recent lab-based reports(in vitro studies) of some Listerine mouthwashes having activity against enveloped viruses, including coronavirus, the available data is insufficient, and no evidence-based clinical conclusions can be drawn with regards to the anti-viral efficacy of Listerine mouthwash at this time,” Johnson & Johnson said.
What we know for sure about mouthwash
Whether you chose to use mouthwash or believe it to be a waste of time, there are some things we know for sure about the effectiveness of mouthwash, when used correctly and as per manufacturer instructions:
- Helps to reduce tooth decay
- Helps to reduce gum inflammation, soreness and mouth ulcers by killing bacteria
- Helps prevent gum disease
- Helps remove debris from hard-to-reach areas of the mouth
Over two years on from the beginning of the pandemic, there is only limited evidence to support pre-procedural mouthwashes being effective in helping to prevent the spread of Covid-19.
Studies are ongoing and researchers have stopped short in recommending it as a change to routine infection control procedure.
However, some mouthwashes have been shown in limited trials to be highly effective in reducing viral load in the mouth, hence some dentists are choosing to recommend patients rinse with CPC and IPM-based mouthwash prior to treatment as an extra risk-mitigation strategy.
Should you choose to incorporate mouthwash into pre-treatment procedure, note that patient consent should be obtained because the patient is not only rinsing for their benefit, but also for the benefit of yourself, your team and the practice.