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A Study on Using Mouthwash before Providing Dental Treatment to Patients in Dental Clinics during the COVID-19 Pandemic
Int J Clin Prev Dent 2021;17(1):21-26
Published online March 31, 2021;
© 2021 International Journal of Clinical Preventive Dentistry.

Ki seok Hong

Moon Dental Hospital, Cheonan, Korea
Correspondence to: Ki seok Hong
Received March 1, 2021; Revised March 19, 2021; Accepted March 24, 2021.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Objective: The objective of the present study was to identify the level of recognition of personnel working for dental care in Korea upon using mouthwash before providing dental treatment for patients during the COVID-19 pandemic.
Methods: Medical personnel currently working in institutions of dental care were selected randomly regardless of their workplaces and types of occupational groups for the survey employing a questionnaire.
Results: Results of the survey revealed that 55.0% of subjects participated in the survey replied that the use of mouthwash would be useful before providing dental treatment while 45.0% of subjects replied that mouthwash may be useful before providing surgical treatment such as extracting teeth or procedures creating aerosols or splashes. Younger subjects, not those over 50s, appeared to dominantly show positive replies upon using mouthwash. Subjects except dentists tended to reply that mouthwash might be employed before providing surgical treatment or procedures that might create aerosols and splashes.
Conclusion: Personnel working in institutions of dental care in Korea appeared to regard the use of mouthwash for patients before providing dental care could help to prevent them from being infected or to prevent the propagation of COVID-19 pandemic virus. Responses varied according to age and occupation. Thus, further studies and more active campaigns equipped with pertinent guidelines seem necessary for the current COVID-19 pandemic.
Keywords : COVID-19, dentistry, SARS-CoV-2, mouthwashes, salivary gland

The recent COVID-19 outbreak has resulted in a global pandemic, affecting the global economy as well as people worldwide. It also has significant effects in the field of dental care [1]. The SARS-CoV-2 virus that caused the epidemic was found in 91.7% of the saliva samples of patients in the initial stage of infection [2]. Thus, the saliva of patients is regarded as a potential channel of COVID-19 propagation [3]. Saliva aerosols containing SARS-CoV-2 viruses seem to be created by coughing, sneezing, breathing, and talking, thereby, becoming sources of propagation of the COVID-19 epidemic. It has been estimated that approximately 40,000 saliva droplets are created from a single cough, which can travel a few meters in the air, propagating the spread of aerosol particulates and promoting the epidemic [4].

In dental clinics, aerosols are created from dental care procedures for patients treated with rotating apparatuses such as hand-pieces and supersonic scaler, contributing to the creation of aerosols containing water, saliva, blood, and microorganisms during the procedure. Since it is difficult to dentists and personnel providing medical services to maintain a distance from their patients of more than 1 meter, they are exposed to the risk of infection with SARS-Cov-2 through aerosols. These aerosols created during dental care procedures may also cause cross-infection in other patients coming to the clinics. However, it would also be very difficult to suppress the potentially risky aerosols created from dental care procedures [5,6].

In general, saliva or water droplets splashes can contaminate an area 3-feet in diameter, whereas aerosols created therefrom may induce sustainable contamination over a wide area, and thus, trigger potential propagation through infection in the clinics [7]. To reduce the risk of SARS-CoV-2 propagation by COVID-19 patients in dental clinics, alleviating the viral load is essential, for which the use of mouthwash has been recommended as an efficient measure [8]. According to recently conducted studies, the use of mouthwash before medical treatments can decrease the load of microorganisms in aerosols created in dental clinics [9]. Many dental clinics have employed mouthwash before providing patients with medical treatment such as tooth extractions to reduce the oral microorganism counts and control dental plaque, a major cause of periodontal disease and dental caries [10-13]. Clinical evidence for preventing the propagation of SARS-CoV-2 through the use of mouthwash has yet to be reported. However, some countries including the United States have recommended the use of mouthwash before providing patients with dental care [14,15]. The Korean Dental Association also recommends the use of mouthwash through its website. The emergence of mutated viruses and the insufficient employment of mouthwash in dental clinics necessitate more active campaigns and concrete guidelines for the use of mouthwash.

Thus, the objective of the present study was to provide specific guidelines for the use of mouthwash before providing patients with dental treatment during the COVID-19 pandemic by determining the level of recognition on the use of mouthwash of the personnel responsible for the dental care before providing patients with dental treatment.

Materials and Methods

The subjects who participated in the present study were medical personnel providing dental care services in private or public dental clinics and hospitals. These subjects were selected regardless of the occupational group or position. The survey was carried out in January 2021. The following questionnaire was used for the survey conducted in the present study. Medical institutions targeted for the distribution of the survey questionnaires were randomly selected. The questionnaires were completed anonymously to maintain privacy and the confidentiality of the collected information.

1. Questionnaire

1) Do you think the use of mouthwash by all patients before dental care would help prevent infection and propagation of the COVID-19 epidemic?

1. Yes, of course

2. It should be applied only in patients before surgical treatment including tooth extraction and dental procedures creating aerosols

2) What is the type of your occupational group?

1. Dentist

2. Another group that provides patients with dental care

3) Identify your age group.

1. 20s

2. 30s

3. 40s

4. Over 50s

2. Statistical analysis

IBM SPSS Statistics for ver. 21.0 (IBM Co., Armonk, NY, USA) was used for all statistical analysis conducted in the present study. To determine differences by age and occupational position in recognizing the use of mouthwash to combat COVID-19 infections from dental procedures, the Chi- squared test was performed after conducting cross-analysis. The level of significance was set at p<0.05.


1. Level of recognition of the use of mouthwash against the COVID-19 pandemic

Regarding whether the use of mouthwash would help prevent infections and propagation of COVID-19 in and from dental clinics, 55.5% of the respondents replied “Yes, of course” while 45.0% replied that “It should be applied only in patients before surgical treatments including tooth extractions or dental procedures creating aerosols” to the question “Do you think the use of mouthwash by all patients before dental care would help prevent infection and propagation of the COVID-19 epidemic?”.

1) Differences in the recognition of respondents in different age groups on the use of mouthwash during the COVID-19 pandemic

The response of the participants on the use of mouthwash showed significant differences among age groups (χ2=9.673, p<0.05). Except for the age group of people over 50s, the respondents in the younger age groups tended to reply that the use of mouthwash prior to dental procedures would help prevent infections and propagation of the COVID-19 epidemic, whereas 100.0% of the respondents in the over 50s replied that the use of mouthwash before dental care would help (Table 1).

Table 1 . Differences in the recognition on the use of mouthwash of respondents in respective age groups during the COVID-19 pandemic

AgeYes, of courseIt can be applied only for cases before providing patients with surgical treatment including teeth extraction of and dental procedure that can create aerosolsχ2 (p)
20s19 (70.4)8 (29.6)9.673 (0.022*)
30s21 (46.7)24 (53.3)
40s20 (47.6)22 (52.4)
Over 50s6 (100.0)0 (0.0)
Total66 (55.0)54 (45.0)

Values are presented as frequency number (%). *p<0.05.

2) Differences in the recognition of the respondents on the use of mouthwash in different occupational groups during the COVID-19 pandemic

The responses on the use of mouthwash showed significant differences among occupational groups (χ2=14.026, p< 0.001). All respondents (100.0%) in the occupational group of dentists replied that the use of mouthwash prior to providing patients with dental procedures would be helpful in preventing infections and propagation of the COVID-19 epidemic, whereas more respondents in occupation groups other than dentists replied that the use of mouthwash before providing patients with dental care would be helpful only before surgical treatments such as tooth extractions and dental procedures known to create aerosols (Table 2).

Table 2 . Differences in the recognition on the use of mouthwash of respondents in respective occupational groups during the COVID-19 pandemic

OccupationYes, of courseIt can be applied only for cases before providing patients with surgical treatments including teeth extraction and dental procedures known to create aerosolsχ2 (p)
Dentist15 (100.0)0 (0.0)14.026 (0.000*)
Respondents other than dentist51 (48.6)54 (51.4)
Total66 (55.0)54 (45.0)

Values are presented as frequency number (%). *p<0.001.


SARS-CoV-2 is an enveloped single-stranded RiboNucleic Acid virus where in the spike protein, which is activated by protease, combines with the angiotensin-converting enzyme 2 (ACE2) receptor to act as a pathogenic organism [16]. The interaction between the protein and the ACE2 receptor plays a role in allowing the virus to enter host cells [17]. The ACE2 receptor is distributed in several parts of the human body. The membrane combined with ACE2 has been found in cells of several tissues, including mucous membranes, gingiva, the tongue, and epithelial cells of the salivary glands, thus predicting the possible routes of infection [18,19].

ACE2 and the proprotein convertase furin are involved in viral invasion into cells and are expressed in salivary glands [20]. High SARS-CoV-2 viral loads have been found in the saliva and periodontal pockets [21,22]. These discoveries suggest that the propagation of the SARS-CoV-2 virus could happen through oral tissues via coughing, sneezing, talking, and during dental procedures [4]. Therefore, decreasing the oral viral load is important in reducing the risk of SARS-CoV-2 virus propagation from patients with COVID-19 infections, for which one effective measure is to reduce the viral load using mouthwash [23].

According to Herrera et al. [24] and Dev Kumar et al. [25], mouthwash containing cetylpyridinium chloride (CPC) or povidone-iodine (PVP-I) can reduce the SARS-CoV-2 viral load, thereby reducing the level of COVID-19 severity. Mouthwash can also reduce the viral load in aerosols created by ordinary dental treatment and droplets in water splashes created by ordinary activity, reducing the risk of virus pro-pagation.

The American Dental Association [14], the Australian Dental Association [26], and the Centers for Disease Control and Prevention [15] all recommend that personnel providing dental care have patients use a preoperative mouthwash containing 0.2% PVP-I before dental surgery. Challacombe et al. [27] stated that the nose and oral cavity of all patients requiring dental care must be rinsed with 0.5% PVP-I solution. The mouthwash targets the sensitivity of the virus to oxidation. In a study conducted recently on 4 patients with COVID-19, the SARS-CoV-2 viral load was decreased significantly by the application of 15 ml of mouthwash containing 1% PVP-I for 1 minute [28].

CPC is a quaternary ammonium compound that exhibits an antiviral effect in patients with influenza. The lysosomotropic mechanism together with its ability to destroy viral capsids may exert a similar effect on COVID-19 [29,30]. Chlorhexi-dine (CHX) is a mouthwash mainly employed in dental clinics to treat periodontal disease and reduce dental plaque. It can increase the permeability of the bacterial cell wall, inducing the dissolution of the bacteria. Therefore, it has been applied as a broad-spectrum antiseptic to treat gram-positive and gram- negative bacteria, aerobic bacteria, facultative anaerobic bacteria, and mold [31]. The in vitro effects of CHX on lipid-enveloped viruses such as Influenza A, parainfluenza, herpesvirus 1, cytomegalovirus, and hepatitis B have been re-ported. However, the effects of CHX on COVID-19, an enveloped virus, have not been compared to other kinds of mouth-wash.

Nonetheless, Yoon et al. [2] reported that the use of 15 ml of 0.12% CHX once for 2 hours could inhibit SARS-CoV-2, suggesting that the mouthwash could help prevent the propagation of COVID-19. Hydrogen peroxide (H2O2) is an odorless, transparent, and colorless liquid mouthwash that has been used in dental clinics [32]. Since SARS-CoV2 is vulnerable to oxidation, the use of mouthwash containing an oxidant such as 1% H2O2 before dental procedures may contribute to reducing the viral load in saliva [33].

Since few studies have been conducted so far, sufficient scientific evidence supporting the recommended use of mouthwash to control of the risk of infection in dental clinics and communities is yet to be reported. Thus, further studies on the use of mouthwash during the COVID-19 pandemic are needed. According to the World Health Organization, preventive measures against SARS-CoV-2 infection generally include wearing a mask, scrubbing hands, ventilating buildings, and maintaining social distance. However, aerosols created from dental procedures can increase the risk of infection and SARS-CoV2 propagation, and thus, require attention. Beyond the use of mouthwash before providing dental treatment, there are several ways to reduce the risk of infection and propagation of disease, such as the appropriate use of personal protective equipment (PPE) and employing effective sterilization procedures.

Above all, screening patients in dental clinics is important for preventing infection with and the propagation of COVID- 19. The personnel providing medical services to patients must be acquainted with the symptoms of COVID-19 and be capable of identifying patients suspected of having COVID-19 infections requiring immediate segregation. Wearing PPE is important for infection control in dental clinics in that splashes and water droplets may contain pathogens mediated through saliva. Thus, dental care providers are obliged to wear protective goggles, face shields, masks, gloves, and caps.

Avoiding the use of a 3-way syringe is desirable to minimize splashes and water droplets while performing oral inspections. Extra-oral radiography such as panoramic radiography and cone-beam computed tomography can be an alternative since intra-oral radiography stimulates salivary secretions and sneezing [6,34]. The creation of splashes contaminated with saliva and water droplets or aerosols can be reduced significantly by using a dental hand-piece or scaler in dental clinics with rubber dams [35]. High-speed dental hand- pieces without anti-retraction valves can reduce the backflow of oral microorganisms into tubes in the equipment used for dental care because it can absorb and discharge saliva into the oral cavity during dental treatment. The saliva may be absorbed into the hand-piece and microorganisms in the saliva might contaminate tubes in the equipment used for dental care, resulting in cross-infection if rubber dams are not used.

Therefore, dental hand-pieces equipped with no shrink-prevention function should not be used during the COVID-19 pandemic. Fortunately, there have been no reports of mass infections or COVID-19 propagation via dental clinics. How-ever, it seems necessary to be prepared for a possible mass infection and the propagation of COVID-19.


In the present study, personnel working in institutions of dental care were found to commonly think that the use of mouthwash by patients before dental procedures could help prevent infections and propagation of the epidemic COVID- 19, although the responses varied according to age and occupation of the respondents. Thus, more active campaigns and preparation of specific guidelines promoting the use of mouthwash in dental clinics seem necessary.

Conflict of Interest

No potential conflict of interest relevant to this article was reported.

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