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 Table of Contents  
Year : 2022  |  Volume : 13  |  Issue : 2  |  Page : 58-63

How has COVID-19 affected dentistry practice? The perspective of future changes in a comprehensive literature review

1 Orthodontist, Private Office, Hamedan, Iran
2 Periodontist, Private Office, Hamedan, Iran
3 Division of Comprehensive Oral Health-Periodontology, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
4 Paediatrician, Private Office, Hamedan, Iran
5 Periodontist, Private Office, Tehran, Iran

Date of Submission12-Feb-2022
Date of Decision09-Apr-2022
Date of Acceptance23-Apr-2022
Date of Web Publication20-Jun-2022

Correspondence Address:
Dr. Sara Soheilifar
3rd Floor, Number 8, Soufi Alley, Pasteur Street, Hamedan
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/srmjrds.srmjrds_26_22

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Background: During the early stages of the COVID-19 pandemic, new guidelines were provided for dental offices to prevent the disease transmission. Dentists suffered a lot of financial and psychological damage as a result of the pandemic. Aim: In this article, the authors reviewed the guidelines provided by the Centers for Disease Control (CDC) and the prevalence of the disease among dentists and their patients, COVID-19 vaccination, emerging new variants of the virus, and future perspective. Methods: PubMed, Scopus, Embase, Web of Science, and Cochrane databases were used to find the publications published from December 2019 to the end of December 2021, discussing the challenges that dentists encountered in the COVID-19 pandemic. Interventional, observational, and review articles in any language were included. The contents were analyzed, and results of the original papers were obtained. Results: A total of 94 articles were found through electronic and hand searching. From them, 59 studies were excluded and 35 fulfilled the inclusion criteria. Publications on the prevalence of COVID-19 cross-infection in dental settings reported a low incidence of the disease while adhering to the CDC guidelines. Conclusion: This shows that the special precautions released for the preventive transmission of COVID-19 in dental clinics are effective measures and while high transmissible variants are circulating in the populations, the guidelines should be followed by dental health-care workers, even in communities with high vaccination rates.

Keywords: COVID-19, dentistry, guidelines, pandemic, SARS-Cov-2, vaccination

How to cite this article:
Soheilifar S, Soheilifar S, Fahimipour F, Soheilifar J, Soheilifar S, Bidgoli M, Ghaedi FB. How has COVID-19 affected dentistry practice? The perspective of future changes in a comprehensive literature review. SRM J Res Dent Sci 2022;13:58-63

How to cite this URL:
Soheilifar S, Soheilifar S, Fahimipour F, Soheilifar J, Soheilifar S, Bidgoli M, Ghaedi FB. How has COVID-19 affected dentistry practice? The perspective of future changes in a comprehensive literature review. SRM J Res Dent Sci [serial online] 2022 [cited 2023 Mar 31];13:58-63. Available from:

  Introduction Top

It is well recognized that the COVID-19 pandemic had influenced dental procedures due to the proximity of patients to the dental health-care workers and also producing aerosols and droplets during the common dental treatments. During the early stages of the pandemic, dental health-care providers were categorized as “very high exposure risk” in the recommendation of the Occupational Safety and Health Administration (OSHA) to prepare workplaces for COVID-19, along with health-care providers who perform aerosol-generating procedures on known or suspected COVID-19 patients. The Centers for Disease Control (CDC) and OSHA emphasized protecting the dental team and also the patients from aerosols generated during clinical care. It is not clear how many dentists and their patients have exactly been infected with COVID-19 before the CDC recommendations and the evidence on the rate of COVID-19 cross-infection in dental offices while adhering to recommendations (before and after vaccination) is rare.

Aerosols produced by some dental equipment such as dental handpieces, air-water syringes, ultrasonic scalers, and air polishing units have the potential of contaminating the air.[1] This contamination may persist for 30 min after the cessation of aerosol-generation procedures;[2] however, using high volume suction alone or in the combination of air conditioning systems may reduce this time. A systematic review evaluated various dental procedures-generating droplets and aerosols and categorized the instruments according to their contamination potential. Ultrasonic scalers, high-speed air-rotors, air-polishers, and air/air+ water syringes were categorized as higher contamination groups. At the same time, prophylaxis with pumice had a moderate risk of aerosol production, and hand scaling and using only water of an air-water syringe were the lower risk producers.[3]

The COVID-19 pandemic and its related safety concerns delayed access to nonemergent dental treatments, which could result in dental problems such as multiple caries in children and adults and progressing periodontal disease, and the community may encounter oral health issues and subsequently overall health problems.[4] On the other hand, most dentists were anxious about getting infected with the virus, and the alterations in dental practice made dentists concerned about the economic implications and the future of their profession.[5]

This review article first reviews the available literature about the necessary changes in dental practice during the 1st month of the COVID-19 pandemic, and the prevalence of cross-infection in dental offices after adhering to recommendations then focuses on existing evidence on what should dentists do after vaccination with COVID-19 vaccines, rising new high-transmissible variants, and also easing the community restrictions.

  Methods Top

PubMed, Scopus, EMBASE, Web of Science, and Cochrane databases were used to find publications published from December 2019 to the end of December 2021, discussing the challenges that dentists encounter in the COVID-19 pandemic. The terms used as keywords were COVID-19, SARS-CoV-2, 2019-nCov, COVID-19 transmission, severe acute respiratory syndrome, coronavirus infection, droplets, aerosol, protective personal equipment (PPE), COVID-19 guidelines, airborne contamination, COVID-19 impact on dentistry, COVID-19 vaccine, vaccine efficacy, SARS-Cov-2 variants, and the immunity after COVID-19 vaccine. The inclusion criteria for screening the papers were those reported on dentistry-related aspects of COVID-19, both before and after vaccination. Interventional, observational, and review articles in any language were included. Articles on the COVID-19 diagnosis and treatment and animal studies were excluded. The databases were reviewed by two reviewers to find eligible articles. Studies were then screened according to titles and abstracts by two independent reviewers. The full texts of possible relevant studies that fulfilled the inclusion criteria were obtained and final articles were chosen. Any conflicts in the process of article selection were resolved by discussion. The contents were analyzed, and results of the original papers were obtained. Furthermore, citations of the article were reviewed for potential relevance. A total of 94 articles were found through electronic and hand searching. From them, 59 studies were excluded and 35 fulfilled the inclusion criteria [Figure 1].
Figure 1: PRISMA Flow Diagram of study selection

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  Discussion Top

Extracted data are provided below:

Special precautions in dentistry during COVID-19 outbreak

The extracted data in this field are from various study types, most of them literature and systematic reviews, and also official guidelines. There are distinctive hierarchal levels to prevent work-associated infectious diseases. The National Institute for Occupational Safety and Health and also CDC suggested some preventive measures, including triage, environmental disinfection and hand hygiene, adequate ventilation, changing the office organization, and PPE.[6]

Patient management

This step includes preventing a possible infected patient from coming to the dental clinic (triage). Triage is recommended for initial evaluation of patients and for detecting patients with a high risk of transmitting SARS-Cov-2. The triage procedure includes investigating the patient's current health status, evaluating body temperature, and questioning whether they recently had a fever or other prominent symptoms of COVID-19.[7] Acquired information should be written in a questionnaire, and also the patient's written consent should be obtained. However, the triage will not detect asymptomatic and presymptomatic patients, and therefore, the best policy is to focus on protecting recommendations perfectly.[8]


This process means the elimination of secondary infectious reservoirs, including hygiene of the hands and surfaces, which have always been necessary for infection control in a dental office; this is applicable to COVID-19 similarly.[9]

All dental chair surfaces and frequently touched surfaces such as desks and chairs should be disinfected with proper disinfectant.

Engineering controls

Isolating dentistry office personnel from the hazardous environment.

Producing aerosols during most dental treatments makes the air in the office contaminated. Hence, adequate ventilation is mandatory to replace the infected air with clean air during an aerosol-generating procedure and after it. Ventilation systems may be utilized in enclosed spaces. UV-C flow germicidal lamps, devices with HEPA filters, and devices that use plasma or fogging with hydrogen peroxide for disinfection are safe and effective in decontaminating the office air.[10]

Administrative control

Changing the office organization can help in reducing the risk of cross-infection.

Using hand instruments instead of ultrasonic scaler devices, considering a minimum of half-hour of waiting time between the patients, rubber dam isolation, using anti-retraction handpieces,[11] and rinsing the oral cavity by mouthwash[12] are some of these suggestions. These protocols can reduce the risk but are unable to eliminate it. Hydrogen peroxide mouthwash (1% H2O2) and also povidone-iodine can be useful for oral disinfection against SARS-CoV-2.[13] However, the results of in vitro studies on chlorhexidine did not show efficacy.[14] There is a hypothesis that the disinfection effect of mouthwashes is not stable due to the high viral load in the throat, nose, saliva, and on the tongue and in the saliva.[15] Results of a systematic literature review confirm the effect of mouthwashes in reducing the microorganisms in aerosols, but it is unclear whether this decrease has effects on clinical infection rate.[16]

Protective personal equipment

PPE for shielding the dental health-care workers mainly includes full-length fluid-proof gowns, face masks, respiratory protective devices, protective eyewear, full-face shields or visor, and double gloving.[7] Because of the SARS-CoV-2 virus diameter (0.06–0.14 mm) in droplets, the most efficient masks are FFP2/N95, FFP3/N99, and N100.[17] During aerosol-generating procedures, dental health-care workers should be protected by an N95 respirator or a respirator with a similar level of protection such as powered air-purifying respirators, elastomeric respirators, etc.[6]

Measures focusing on eliminating the source of virus in the dental environment provide more protection than the measures working on protecting equipment for dental health-care workers. The strength of the evidence on the necessary changes to dental offices is not high and more interventional controlled studies are needed.

Dental care in 1st week of COVID-19 pandemic

Most of the data included in this study about this topic are from observational studies. Although 1st week and months of COVID-19 pandemic have been passed, the experience of encountering this pandemic can help practitioners to overcome the difficulties of future pandemics. In 1st week, American Dental Association (ADA) categorized dental care treatment into three groups; emergencies, urgent, and nonemergencies. According to ADA guidance, emergency dental problems are life-threatening and should be treated immediately. Urgent dental problems should be treated in a minimally invasive manner, and nonemergencies should be postponed up to a better condition in the pandemic control.[18] It seems that high potential procedures should be deferred or done with rigorous observance of protective protocols in 1st week of pandemics.

This guidance was essential in the 1st month of COVID-19 outbreak due to insufficient information, unavailability of diagnosis tests, and PPE.[19] However, it seems that by knowing transmission routes and appropriate PPE, clinicians can overcome transmission of future possible pandemics better than COVID-19 outbreak. A few publications on the accumulative prevalence and incidence rate of COVID-19 among dental practitioners reported that U.S. dentists highly adhered to upgraded infection control strategies released by CDC, leading to a low cumulative prevalence of COVID-19.[20] According to the existed evidence, dentists could protect their patients, their dental team members, and themselves by strict adherence to enhanced infection control protocols.[21] However, more epidemiological studies are needed to find precise prevalence and incidence rate of COVID-19 transmission in dental settings during dental procedures.

COVID-19 vaccines

While the world was encountering high rates of COVID-19 infections, vaccines became the hopeful savior, and vaccine research and development had become a top priority of public health. Some countries worldwide try to access COVID-19 vaccines; however, the low- and medium-income populations did not access enough doses of vaccines.

COVID-19 vaccines from different developers have passed phase III of clinical trials and have been approved for emergency use. The developed vaccines have different working mechanisms to protect individuals against the disease, including inactivated virus vaccines, nucleic acid (DNA or RNA) vaccines, viral vector vaccines, and recombinant protein vaccines.

Worldwide, now over 53% of the population are fully vaccinated as of February 01, 2022, while vaccination was started in high-income countries, and the vaccination rate gradually increased all over the world. Some countries, with over 60% of their population being fully vaccinated, had seen a drop in COVID-19 cases for several months. However, worldwide access to COVID-19 vaccines in a short time was necessary to manage the pandemic, achieve global population immunity, prevent the production of the new variant, and control the pandemic. Mutations of the virus generate the changes and result in the new variants as a result of the virus's widely circulation in a population. Multiple variants of coronavirus are reported to date, but some have no significant impact on the virus properties; however, some mutations affect the virus transmission or pathogenicity.[22] The variants that have raised more concern are the U.K. B.1.1.7 or Alpha variant, South Africa B.1.351 or Beta variant, Brazil P. 1 or Gamma variant, U.S. California B.1.427 and U.S. California B.1.429 or Epsilon variant, India B.1.617.2 or Delta variant and B.1.1.529 or Omicron variant.[23] As the vaccines were emerging, the effect of these variants on existing vaccines' efficacy and effectiveness was a major concern. Some publications reported decreased efficacy of vaccines against beta variants.[24] The delta variant with increased transmissibility had also the ability to escape from neutralizing antibodies.[25] However, the mutations in the virus did not make vaccines completely ineffective, and updated data has shown that although the vaccines' efficacy may be reduced against the Delta variant, they can prevent severe disease and death caused by COVID-19 significantly.[26] Reports of new studies on Omicron variant explain specific mutations that result in increased transmissibility, risk of reinfection, or vaccine breakthrough infection but still vaccines are effective against severe disease and hospitalization. Over time, the vaccines' effectiveness may be reduced, and a booster dose is recommended after the second dose vaccine to enhance protection against the Omicron variant. These results are reported from interventional studies with the high level of evidence.

Recommendations after being fully vaccinated

To find the recommendations after COVID-19 vaccination, some observational studies and also several guidelines that met our study inclusion criteria were reviewed. While the populations were being vaccinated against COVID-19, modeling studies suggested that adherence to prevention measures (nonpharmaceutical interventions), such as wearing masks, physical distancing, and enhanced hygiene, must be combined with fast and widespread vaccine implementation to eliminate the pandemic successfully.[27] Such a combination of strategies was also considered essential to reduce the level of the vaccine-induced herd immunity threshold needed to control COVID-19 and return to everyday life.[28] Hence, there was a hypothesis that increasing vaccination rates in a short time and before exposing the community to a new variant may allow relaxing the nonpharmaceutical interventions without the remarkable impact on COVID-19 control.[29] However, in countries where early relaxation of nonpharmaceutical interventions is combined with increased transmissibility of some new variants (Delta and Omicron variants), the benefits brought by the vaccine in the communities were reduced soon.[30]

Before emerging Delta and Omicron variants, CDC suggested that fully vaccinated people can resume some activities without wearing a mask or physically distancing in highly vaccinated countries. However, these recommendations about relaxing the safety precautions were not intended for healthcare settings, even in the countries experiencing dropping the number of involved population.[31] It was suggested that all fully vaccinated health-care workers adhere to the special precautions recommended by CDC at the beginning of the pandemic, independent of the vaccination rate of their country.[32] There were many reports of breakthrough infection among fully vaccinated health-care workers in the 1st month of being fully vaccinated.[33] Efficacy of the vaccine is not 100% and the efficacy has dropped more against new variants. For these reasons, until there is no circulation of the virus in the community or more effective vaccines and drugs for COVID-19 could be accessed for all the communities, maintaining the prevention measures is incredibly important. Hence, in the countries with high vaccination coverage, health-care workers should adhere to the precautions in the dental setting, too, even after receiving a booster shot, or a history of previous infection, and while these high transmissible variants are present. The evidence in this field is not high and more studies are needed.

Future perspective

At this point, no one knows what will happen to this pandemic. Despite extensive global vaccination, it is still spreading worldwide. Some researchers have postulated three possible scenarios:

  1. Continuation of the pandemic in the near future with no noticeable reduction in the global spread and the burden of the disease. Improving the worldwide distribution of vaccines, diagnosis devices, and treatment methods would decrease the chance of occurrence of this scenario
  2. Transition to seasonal epidemic disease, like influenza. The evolution of more effective treatments would propel the pandemic to this scenario
  3. Transition to endemic disease confining to particular regions.[34]

No one knows which scenario would occur in actuality; however, most scientists believe that this pandemic will not be the last pandemic of the century. Future infectious pandemics are pretty possible.[35] Politicians, scientists, and policy-makers were not well prepared to face the outbreak of the COVID-19. The experience resulting from this worldwide pandemic would help us encounter future pandemics. Changes in dentistry practice during this period led to the re-organization of the usual method of office management. Expanding teledentistry, improving PPE, and re-organizing time management in offices would empower us to adapt to future pandemics without being extensively affected.

  Conclusion Top

The special precautions released for the preventive transmission of COVID-19 in dental clinics are an effective measure and while high transmissible variants are circulating in the populations, the guidelines should be followed by dental health-care workers, and some aerosol producing dental procedures should be considered high-risk, even after being vaccinated. However, due to high transmissibility of the disease, its severity, and risk of morbidity and mortality, there was not possible to perform controlled interventional studies, so the strength of evidence is low and more controlled interventional studies are needed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

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