Letter to the Editor Open Access
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Methodol. Sep 20, 2022; 12(5): 461-464
Published online Sep 20, 2022. doi: 10.5662/wjm.v12.i5.461
Mouth shield to minimize airborne transmission risk of COVID-19 and other infectious diseases in the dental office
Mohiddin R Dimashkieh, Mohammad Zakaria Nassani, Yousef Fouad Talic, Department of Restorative and Prosthetic Dental Sciences, College of Dentistry, Dar Al Uloom University, Riyadh 13314, Saudi Arabia
Ali Alqerban, Department of Preventive Dental Sciences, College of Dentistry, Dar Al Uloom University, Riyadh 13314, Saudi Arabia
Ali Alqerban, Department of Preventive Dental Sciences, College of Dentistry, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
Amir M Demachkia, Department of Dental Materials and Prosthodontics, São Paulo State University - Institute of Science and Technology, São José dos Campos, São Paulo 12224-300, Brazil
ORCID number: Mohammad Zakaria Nassani (0000-0003-0927-895X).
Author contributions: Dimashkieh MR proposed the topic of the paper; Dimashkieh MR and Nassani MZ prepared the original draft; Talic YF, Alqerban A and Demachkia AM reviewed and revised the original draft; all authors discussed and agreed the final draft.
Conflict-of-interest statement: All authors declare no conflict of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Mohammad Zakaria Nassani, DDS, PhD, Associate Professor, Department of Restorative and Prosthetic Dental Sciences, College of Dentistry, Dar Al Uloom University, Northen Ring Road, Exit 7, Riyadh 13314, Saudi Arabia. mznassani@dau.edu.sa
Received: June 1, 2022
Peer-review started: June 1, 2022
First decision: June 27, 2022
Revised: July 4, 2022
Accepted: August 7, 2022
Article in press: August 7, 2022
Published online: September 20, 2022


Transmission of coronavirus disease (COVID-19) and other infectious diseases is a significant risk during dental procedures because most dental interventions involve aerosols or droplets that could contaminate the surrounding environment. Current protection guidelines to address the high risk of droplets, aerosols, and airborne particle transmission of COVID-19 in the dental office recommend minimizing aerosol-generating procedures. In this paper, an innovative mouth shield is presented that should minimize water backsplash from the air-water syringe during dental treatment. The mouth shield can be added to the personal protective equipment to provide the dental team with extra protection. It can be made of different materials, is straightforward, inexpensive, and safe to fabricate, and is easy to use.

Key Words: Mouth shield, Transmission, Dentistry, COVID-19, Airborne, Droplets, Aerosols, Infectious diseases

Core Tip: This letter to the editor presents an innovative mouth shield to increase the protection of the dental team against the water backsplash of aerosols, droplets, and airborne particles during dental procedures.


The coronavirus disease (COVID-19) pandemic has spread fear and anxiety across the globe because of its high death toll[1]. Various strategies have been introduced to combat the transmission of COVID-19 and reduce its severity, including the expedited development and approval of vaccines[2]. The risk of transmission of COVID-19 in the dental office has led to specific treatment guidelines and protocols, including the minimal use of aerosol- or droplet-generating procedures[3-6]. However, most dental interventions produce aerosols and droplets, contaminating the surrounding environment and leaving dental personnel at risk of acquiring COVID-19 from infected patients. Although non-emergency dental services were halted at the outset of the pandemic, the long duration of the pandemic has required dental practices to resume their services, but with additional precautions and careful triage of patients[7]. Strict adherence to preventive and protective measures became the mantra for oral care services to maintain an active dental practice at the era of COVID-19[8,9]. The aim of this paper is to introduce an innovative, straightforward, and inexpensive personal protection device that minimizes water backsplash from air-water syringes during cavity washing and drying. The goal was to develop a special mouth shield that should minimize the transmission risk of COVID-19 and other infectious diseases via airborne droplets or aerosols in the dental office.


The mouth shield attaches to the air-water syringe tip and consists of a transparent shield made from the plastic lid of a conventional, disposable, crystal clear plastic cup. The center of the lid is perforated with a 3.5-mm-diameter twist drill to produce a frictional fit with the tip of an air-water syringe and form a disposable mouth shield (Figures 1A and B). The mouth shield can be positioned to maintain light contact with the patient’s lips (Figure 1C). It can be used with most air-water syringes during various dental procedures. Different size lids made from disposable, crystal clear polyethylene terephthalate plastic or polystyrene can be selected to accommodate patients with varying degrees of mouth opening. The front surface of the shield can be relined with a water absorbent liner to capture scattered droplets. The mouth shield can also be easily adjusted forward and backward along the tip (nozzle) of the air-water syringe for convenience (video).

Figure 1
Figure 1 Crystal clear plastic cup lid mouth shield. A: Traditional, disposable, crystal clear plastic cup lid perforated in the center using a 3.5-mm-diameter twist drill and a disposable air-water syringe tip; B: The air water syringe tip is inserted with a friction fit through the central hole of the plastic cover to form a mouth shield; C: The mouth shield rests lightly on the patient’s lips, sealing the mouth during water/air spray.

The COVID-19 pandemic and the increased risk of infection prompted the authors to develop a cost-effective disposable mouth shield to provide protection against back splashes of aerosols, droplets, and airborne particles during dental treatment. An air-water syringe is essential for dental procedures such as etching, bonding, cavity cleansing, and impression making. Contamination from the aerosol could be a major source of infection[10]. The association between aerosols, droplets, and splatter and the transmission of COVID-19 has been emphasized, and recommendations have been made to reduce their generation during the coronavirus pandemic[4,11-13]. Furthermore, emphasis has been placed on the role of personal protective equipment such as medical masks, protective face shields, and goggles in preventing and minimizing airborne transmission of COVID-19[14,15]. Despite the use of personal protective equipment, transmission of the viral infection is still possible, and additional preventive precautions are advised. For example, while wearing magnifying loops, it is not feasible to wear a face shield, leaving the face of the operator exposed to contamination. The described mouth shield provides additional protection at minimal cost. It is designed to prevent water backsplash out of the oral cavity during mouth/tooth washing and drying, minimizing contamination of the surrounding environment and dental personnel. Being transparent, the shield will allow light to reach the field of operation and allow the operator to easily see into the patient’s mouth. The described mouth shield has been successfully implemented and evaluated in our dental practice. Nevertheless, the effectiveness of the mouth shield in minimizing the airborne aerosols and droplets spread during dental treatment should be investigated, and its role in protecting against infectious diseases, with a comparison of the load of produced aerosols, droplets and airborne particles with and without this shield, should be examined before this shield can be adopted for global use.


The authors would like to thank the Deanship of Graduate Studies and Scientific Research at Dar Al Uloom University for supporting the publication of this paper.


Provenance and peer review: Unsolicited article; Externally peer reviewed.

Peer-review model: Single blind

Corresponding Author's Membership in Professional Societies: Syrian Dental Association, 1503.

Specialty type: Medical laboratory technology

Country/Territory of origin: Saudi Arabia

Peer-review report’s scientific quality classification

Grade A (Excellent): 0

Grade B (Very good): B, B

Grade C (Good): 0

Grade D (Fair): 0

Grade E (Poor): 0

P-Reviewer: Kalani M, Iran; Nalunkuma R, Uganda S-Editor: Wang LL L-Editor: A P-Editor: Wang LL

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