Efficacy of Mouthwashes Delivered via Dental Unit Waterlines in Reducing Aerosolized Surrogate SARS-CoV-2
et al., Medical Science Monitor, doi:10.12659/MSM.950753, Feb 2026
58th treatment shown to reduce risk in
September 2025, now with p = 0.0035 from 4 studies.
Lower risk for recovery and viral clearance.
No treatment is 100% effective. Protocols
combine treatments.
6,600+ studies for
220+ treatments. c19early.org
|
In vitro study testing mouthwashes delivered through dental unit waterlines for reducing aerosolized surrogate SARS-CoV-2 (human coronavirus OC43). The study used suspension tests, carrier tests, and a novel 3D-printed aerosol model to evaluate five mouthwashes: chlorhexidine, cetylpyridinium chloride (CPC), hydrogen peroxide, povidone-iodine (PVP-I), and Oral7. All mouthwashes significantly reduced viral load within 30 seconds, with CPC, PVP-I, and Oral7 achieving >99.99% viral reduction. Only PVP-I and Oral7 were non-cytotoxic to host cells in culture, while mild cytotoxic effects were seen for the others. The study is in vitro using a coronavirus surrogate rather than actual SARS-CoV-2, and cytotoxicity results from cell culture may not reflect real-world mucosal safety.
2 preclinical studies support the efficacy of cetylpyridinium chloride for COVID-19:
Hup et al., 27 Feb 2026, USA, peer-reviewed, 3 authors.
Contact: chaiwl@um.edu.my.
In vitro studies are an important part of preclinical research, however results may be very different in vivo.
Efficacy of Mouthwashes Delivered via Dental Unit Waterlines in Reducing Aerosolized Surrogate SARS-CoV-2
Medical Science Monitor, doi:10.12659/msm.950753
Background: Preoperative mouthwashes are recommended to reduce viral transmission during aerosol-generating procedures (AGP) in dental settings. However, their effectiveness may be compromised due to dilution by continuous water flow from dental unit waterlines (DUWL). This study evaluated the virucidal efficacy of various mouthwashes when delivered through DUWL using a novel 3D-printed dental aerosol model, with human coronavirus OC43 (hCoV-OC43) as a surrogate for SARS-CoV-2.
Material/Methods: Five mouthwashes -0.12% chlorhexidine digluconate (CHX), 0.07% cetylpyridinium chloride (CPC), 1% hydrogen peroxide (HP), 0.2% povidone-iodine (PVP-I), and Oral7 ® -were assessed using suspension and carrier tests at 3 exposure times (30 s, 2 min, and 5 min). Viral infectivity was measured by median tissue culture infectious dose (TCID 50 /mL), and log reduction values (LRVs) were calculated. The most effective mouthwashes were further evaluated in a novel 3D-printed aerosol model simulating mouthwash delivery through DUWL during AGP.
Results: All tested mouthwashes significantly reduced viral infectivity within 30 s. CPC, PVP-I, and Oral7 ® achieved >4 log 10 reductions (>99.99%) in suspension and aerosol tests. However, only PVP-I and Oral7 ® appeared to be non-cytotoxic to the host cells.
Conclusions: PVP-I and Oral7 ® mouthwashes, when delivered via DUWL, rapidly and effectively reduced aerosolized surrogate SARS-CoV-2 within 30 s in this study, while remaining non-cytotoxic to the host cells. These findings support their potential integration into clinical infection control protocols during AGP.
Declaration of Figures' Authenticity All figures submitted have been created by the authors who confirm that the images are original with no duplication and have not been previously published in whole or in part.
References
Allison, Dowson, Jakubovics, Waterline disinfectants reduce dental bioaerosols: A multitracer validation, J Dent Res
Allison, Tiede, Holliday, Bioaerosols and airborne transmission in the dental clinic, Int Dent J
Altaie, Hamdy, Venkatachalam, Estimating the viral loads of SARS-CoV-2 in the oral cavity when complicated with periapical lesions, BMC Oral Health
Barker, Alqobaly, Shaikh, Biological evaluation of oral care products using 3D tissue-engineered in vitro models of plaque-induced gingivitis, Dent J
Campione, Lanna, Cosio, Lactoferrin against SARS-CoV-2: In vitro and in silico evidences, Front Pharmacol
Chaudhary, Melkonyan, Meethil, Estimating salivary carriage of severe acute respiratory syndrome coronavirus 2 in nonsymptomatic people and efficacy of mouthrinse in reducing viral load: A randomized controlled trial, J Am Dent Assoc
Chopra, Sivaraman, Radhakrishnan, Can povidone iodine gargle/mouthrinse inactivate SARS-CoV-2 and decrease the risk of nosocomial and community transmission during the COVID-19 pandemic? An evidence-based update, Jpn Dent Sci Rev
Dhama, Khan, Tiwari, Coronavirus disease 2019-COVID-19, Clin Microbiol Rev
Ebrahimi, Shamshiri, Alebouyeh, Mohebbi, Effectiveness of mouthwashes on reducing SARS-CoV-2 viral load in oral cavity: A systematic review and meta-analysis, BMC Oral Health
Eduardo, Corrêa, Heller, Salivary SARS-CoV-2 load reduction with mouthwash use: A randomized pilot clinical trial, Heliyon
Ehsanifar, Airborne aerosols particles and COVID-19 transition, Environ Res
Eker, Duman, Ertürk, Karav, The potential of lactoferrin as antiviral and immune-modulating agent in viral infectious diseases, Front Immunol
Frank, Brown, Capriotti, In vitro efficacy of a povidone-iodine nasal antiseptic for rapid inactivation of SARS-CoV-2, JAMA Otolaryngol Head Neck Surg
Fuse, Ito, Yamaguchi, Tsukada, High ingestion rate of iodine from povidone-iodine mouthwash, Biol Trace Elem Res
Hassandarvish, Tiong, Mohamed, In vitro virucidal activity of povidone iodine gargle and mouthwash against SARS-CoV-2: Implications for dental practice, Br Dent J
Innes, Johnson, Al-Yaseen, A systematic review of droplet and aerosol generation in dentistry, J Dent
Khorshidian, Khanniri, Koushki, An overview of antimicrobial activity of lysozyme and its functionality in Cheese, Front Nutr
Kim, Lee, Human coronavirus OC43 as a low-risk model to study COVID-19, Viruses
Kőhidai, Takács, Lajkó, The effects of mouthwashes in human gingiva epithelial progenitor (HGEPp) cells, Clin Oral Investig
Lei, Yang, Hu, Sun, On the calculation of TCID(50) for quantitation of virus infectivity, Virol Sin
Lindsley, Blachere, Martin, Law, NIOSH Manual of Analytical Methods (NMAM)
Mann, Ndung, The potential of lactoferrin, ovotransferrin and lysozyme as antiviral and immune-modulating agents in COVID-19, Future Virology
Meister, Brüggemann, Becker, Virucidal activity of a plant-oilbased oral rinse against respiratory viruses, J Hosp Infect
Moharamzadeh, Franklin, Brook, Van Noort, Biologic assessment of antiseptic mouthwashes using a three-dimensional human oral mucosal model, J Periodontol
Müller, Eick, Moritz, Cytotoxicity and Antimicrobial activity of oral rinses in vitro, Biomed Res Int
Ojha, Jessop, Bosio, Peterson, Effective inhibition of HCoV-OC43 and SARS-CoV-2 by phytochemicals in vitro and in vivo, Int J Antimicrob Agents
Organization, KCQiA0fu5BhDQARIsAMXUBOIZ1q Qi4R-3eZxshd1zm4_cCvoU6AI-HGoj3_KbtediO_dJmFl2fAIaAuwZEALw_wcB
Pawar, Garg, Mehta, Dang, Breaking the chain of infection: dental unit water quality control, J Clin Diagn Res
Peng, Xu, Li, Transmission routes of 2019-nCoV and controls in dental practice, Int J Oral Sci
Schirtzinger, Kim, Davis, Improving human coronavirus OC43 (HCoV-OC43) research results comparability in studies using HCoV-OC43 as a surrogate for SARS-CoV-2, J Virol Methods
Scotland, Literature review and recommendations: Management of dental unit waterlines, NHS
Seneviratne, Balan, Ko, Efficacy of commercial mouth-rinses on SARS-CoV-2 viral load in saliva: Randomized control trial in Singapore, Infection
Silva, Branco, Soares, Mesquita, Sousa, SARS-CoV-2 air sampling: A systematic review on the methodologies for detection and infectivity, Indoor Air
Song, Zhang, Zhu, Lysozyme protects against severe acute respiratory syndrome coronavirus 2 infection and inflammation in human corneal epithelial cells, Invest Ophthalmol Vis Sci
Steins, Carroll, Choong, Cell death and barrier disruption by clinically used iodine concentrations, Life Sci Alliance
Toschi, Mercado, Henz, Antiviral effect of oral antiseptic solutions commonly used in dentistry practice: A scoping review, Dentistry Review
Wu, Shi, Yu, Disinfection methods of dental unit waterlines contamination: a systematic review, J Med Microbiol
Ziaeefar, Bostanghadiri, Yousefzadeh, The efficacy of mouthwashes in reducing SARS-CoV-2 viral loads in human saliva: A systematic review, New Microbes New Infect
DOI record:
{
"DOI": "10.12659/msm.950753",
"ISSN": [
"1643-3750"
],
"URL": "http://dx.doi.org/10.12659/MSM.950753",
"alternative-id": [
"950753"
],
"author": [
{
"affiliation": [
{
"name": "Department of Restorative Dentistry, Faculty of Dentistry, Universiti Malaya, Kuala Lumpur, Malaysia"
}
],
"family": "Hup",
"given": "Wendy Wan Yee",
"sequence": "first"
},
{
"affiliation": [
{
"name": "Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia"
}
],
"family": "Chang",
"given": "Li-Yen",
"sequence": "additional"
},
{
"affiliation": [
{
"name": "Department of Restorative Dentistry, Faculty of Dentistry, Universiti Malaya, Kuala Lumpur, Malaysia"
}
],
"family": "Chai",
"given": "Wen Lin",
"sequence": "additional"
}
],
"container-title": "Medical Science Monitor",
"container-title-short": "Med Sci Monit",
"content-domain": {
"crossmark-restriction": false,
"domain": []
},
"created": {
"date-parts": [
[
2025,
12,
26
]
],
"date-time": "2025-12-26T10:40:41Z",
"timestamp": 1766745641000
},
"deposited": {
"date-parts": [
[
2026,
2,
27
]
],
"date-time": "2026-02-27T06:14:12Z",
"timestamp": 1772172852000
},
"indexed": {
"date-parts": [
[
2026,
2,
27
]
],
"date-time": "2026-02-27T08:03:00Z",
"timestamp": 1772179380939,
"version": "3.50.1"
},
"is-referenced-by-count": 0,
"issued": {
"date-parts": [
[
2026,
2,
27
]
]
},
"language": "en",
"link": [
{
"URL": "https://www.medscimonit.com/download/index/idArt/950753",
"content-type": "unspecified",
"content-version": "vor",
"intended-application": "similarity-checking"
}
],
"member": "4947",
"original-title": [],
"prefix": "10.12659",
"published": {
"date-parts": [
[
2026,
2,
27
]
]
},
"published-online": {
"date-parts": [
[
2026,
2,
27
]
]
},
"publisher": "International Scientific Information, Inc.",
"reference-count": 0,
"references-count": 0,
"relation": {},
"resource": {
"primary": {
"URL": "https://www.medscimonit.com/abstract/index/idArt/950753"
}
},
"score": 1,
"short-title": [],
"source": "Crossref",
"subject": [],
"subtitle": [],
"title": "Efficacy of Mouthwashes Delivered via Dental Unit Waterlines in Reducing Aerosolized Surrogate SARS-CoV-2",
"type": "journal-article",
"volume": "32"
}
hup