Impact of COVID-19 on Dental Practices in El Salvador and Mexico: A Comprehensive Survey Analysis

Background and objectives: This study aimed to identify the relationship between prevention measures and protective barriers in dental practice in El Salvador and Mexico during the COVID-19 pandemic in 2020 and 2021. Materials and methods: A longitudinal study was conducted from June 2020 to December 2021, involving 1,719 dentists divided into four groups based on location and year. A 20-question survey in Spanish was utilized and validated with a Cronbach's alpha value of 0.84. Results: The use of phone triage (OR = 1.3), thermometers (OR = 1.4), physical distancing (OR = 1.7), and face shields (OR = 2.6) was significantly associated with dental practice in both countries during the pandemic. Conclusions: During 2020 and 2021, dental care in El Salvador and Mexico was significantly linked to COVID-19 preventive measures. Phone triage, thermometers, distancing, and face shields positively correlated with dental services. National health agencies should promote the use of minimum preventive measures in dental care, preparing for potential reinfections or new pandemics from emerging virus variants.


Introduction
In January 2020, the Chinese Illness Prevention and Control Center officially announced a coronavirus as the pathogen causing COVID-19 [1].Since then, COVID-19 has emerged as a significant public health issue, altering lifestyles worldwide [2].As of September 2022, 609 million cases had been identified, and 6.5 million deaths were reported globally [3].Various health professions have been deemed high-risk due to virus transmission.Consequently, modifications in health services and the implementation of preventive measures and protection barriers in clinical practice became imperative [4].
Dental interventions, including direct or indirect contact with mouth tissues, instrument handling, and aerosol generation, pose risks for COVID-19 transmission among dentists and patients [4,5].As a preventive strategy, the World Health Organization (known as OMS in Spanish), Guidance for Dental Settings, and the Cochrane community initially recommended restricting routine oral health services to emergencies in many world regions [6][7][8].Subsequently, governments worldwide established prevention protocols related to patient services as part of their pandemic initiatives [9].
In 2020, standard infection control measures in routine clinical practices seemed inadequate to halt the spread of COVID-19.Health professionals had to adapt their clinical practices to serve patients during the pandemic [10].Some of these preventive measures included reducing the number of dental service locations, using phone triage, infrared thermometers, handwashing, maintaining physical distancing (at least one meter between patients), employing techniques to prevent aerosol generation, and surface disinfection [11].
Additionally, protective barriers, such as gloves, fluid-resistant face masks, safety goggles or face shields,

Study instrument (questionnaire design)
After reviewing national and international publications, 16 questions in Spanish were formulated (Appendices).The survey assessed variables such as sociodemographic characteristics, dental care service, prevention measures, and personal protection barriers.Responses were dichotomous (Yes or No).The questionnaire underwent pre-testing for validity and reliability with 30 dentists, achieving a satisfactory Cronbach's alpha value of 0.84 (p < 0.05).

Two periods of time (longitudinal study)
The questionnaire was distributed during two periods in El Salvador and Mexico: first, between June and July 2020, and second, between October and December 2021.

Statistical analysis
In the univariate analysis, categorical variables were presented as frequencies and percentages, while continuous variables were expressed as means and standard deviations.The bivariate analysis utilized the Chi-square test to determine differences between groups.A binary logistic regression analysis was constructed with dental care service as the dependent variable (1 for presence and 0 for absence).Independent variables included infrared thermometer, phone triage, handwashing, physical distancing (at least one meter between patients), face shield, and disposable gown.
A variance inflation factor (VIF) analysis test was conducted to detect and mitigate multicollinearity among the independent variables.The specification error test verified the assumption that the response variable's logit is a linear combination of the independent variables.After establishing the main effects, interactions were tested, but none were significant.The model's overall fit was assessed using the goodness of fit test.
The association between dependent and independent variables is presented as odds ratios (OR) with 95% confidence intervals (CI).P-values < 0.05 were deemed statistically significant.Data was analyzed using JMP ver.15 (SAS Institute, Cary, NC) statistical software [13].

Discussion
The onset of the COVID-19 pandemic necessitated modifications in clinical care and practice across the healthcare sector.This study aimed to identify the association between dental care services and the preventive measures and protective barriers employed in clinical practice in El Salvador and Mexico during the years 2020 and 2021.Given the findings, we believe it is essential to identify and analyze dental care services, preventive measures, and protective barriers in clinical settings to enhance patient care.

Health care service
During the first months of the pandemic, healthcare workers around the world seemed to have a positive attitude, good knowledge, and good management of preventive measures when facing the COVID-19 pandemic.For example, in the study by Shi et al., the authors found that in a Chinese population made up of psychiatric doctors and nurses, 90% of them had extensive knowledge about COVID-19.In addition, 60% of those surveyed had received training in the management of suspicious patients or patients with COVID-19.
Likewise, almost 80% of those surveyed were willing to care for patients with COVID-19 [14].
In the American continent, health professionals also had to make changes to care services during the pandemic [15].To minimize physical contact between hospital staff and patients, some hospitals reduced their staff presence by up to 80%.Non-urgent patient appointments were also postponed or canceled.While specialized patient care was feasible in the developed nations of the Americas, the situation was more challenging in less developed countries.Initially, healthcare workers maintained an optimistic outlook [16,17].
However, although specialized patient care could be carried out in developed countries of the American continent, the situation was more complicated in less developed countries [18].In addition, even though at first health workers had an optimistic outlook, as the pandemic period lengthened, the positive attitude was lost and a great deal of stress and concern began to exist among health workers [19].
In the dental community, Posse et al. conducted a survey spanning 59 countries with approximately 400 participating dentists.The study reported that 80% of the dentists limited their clinical activities, with 50% attending only to dental emergencies [16].Moraes et al. reported a cross-sectional study with a sample of Brazilian dentists.The study found that 36% of dentists suspended dental care, while 58% treated only emergencies [20].Our survey's initial results in El Salvador and Mexico align with these findings.A significant number of dentists limited their clinical practice during the pandemic's first wave.Those who continued to provide dental care primarily treated emergencies, adhering to recommended preventive measures [16,20,21].
Moraes et al. conducted another study during the pandemic's second wave in Brazil in May 2021.This survey, which involved around 1,900 dentists, analyzed their clinical practice, knowledge, and attitudes regarding the pandemic.A third of the respondents expressed confidence in vaccine efficacy, with 96% having received at least one vaccine dose.Additionally, 27% reported having contracted COVID-19.The impact of the pandemic on their clinical practice during the second wave was less pronounced than during the first.Most felt well-prepared to treat COVID-19 patients, a sentiment that aligns with our findings in Mexico, where the majority of dentists continued treating patients while adhering to recommended preventive measures [22].
After conducting a bibliographic search, we did not find any articles related to the risk of COVID-19 infection among dentists in Mexico or El Salvador.However, in the United States, the risk of a dentist becoming infected with COVID-19, when using preventive measures, was calculated to be 1 in 13,000 [23].
Brazil was the first country in Latin America to report a positive case of COVID-19.This case was specifically in the state of São Paulo, where an approximately 60-year-old individual, who had traveled from Italy, was diagnosed with the disease [24].
Various authors in Europe and America have identified a significant number of dentists infected with COVID-19 [16].Moraes et al. reported that, in a sample of 2,127 dentists from 11 Latin American countries, nearly 5% were found to be infected by COVID-19 [9].In light of these findings, several researchers have published studies related to the use of preventive measures and protective barriers [25].In studies focusing on dentists, varied results have been reported concerning their knowledge of COVID-19 and the implementation of preventive measures.Kamate et al. conducted a survey spanning five continents to explore changes in dental practices during the COVID-19 crisis.An overwhelming 99% of the participants indicated that they adopted preventive measures against COVID-19, though the specific measures were not detailed [27].Gambhir et al. carried out a survey involving approximately 200 dentists.While a majority displayed a comprehensive understanding of COVID-19 and its transmission routes, only 30% reported a thorough knowledge and utilization of personal protective equipment [28].

Preventive measures and protective barriers
Several authors have highlighted the widespread use of preventive measures such as phone triage, infrared thermometers, handwashing, physical distancing (maintaining at least one meter between patients), and techniques to minimize aerosol generation [24,26,29].Gold et al. noted that in US hospitals, every admitted patient underwent evaluation both over the phone and in person to ascertain potential COVID-19 infection.Those suspected were isolated for 14 days, with confirmed cases being closely monitored throughout their isolation period.Additionally, hospitals introduced measures to reduce physical interactions between doctors and patients [17].Abed et al. executed a national web-based cross-sectional survey from November 2020 to January 2021.Their findings revealed that in Qatar, only 50% of health professionals, a majority of whom were dentists, utilized personal protective equipment.The most commonly adopted infection control measure was handwashing [30].
Balkaran et al. conducted a study across Caribbean countries using a questionnaire distributed via email.Although this study spanned several countries, it only involved 152 dentist participants.From the results, a majority of the dentists identified aerosol production during dental consultations as the primary source of contagion.Nearly 70% of the participants expressed willingness to get vaccinated, and approximately 95% reported using personal protective equipment [31].
Dentists in Mexico and El Salvador have been diligent in adhering to preventive measures and using personal protective equipment, a trend consistent with findings from previous studies [21,32].
These findings can be utilized to a) gather information on the subject, b) reevaluate the preventive measures and protective barriers currently in use to determine their relevance in professional practice and c) develop and implement protocols aimed at addressing and mitigating challenges similar to or more complex than those posed by the COVID-19 pandemic.It is plausible that the identified variables associated with dental care services might become standard practices to enhance patient care.The current situation underscores the importance of preventive practices and minimally invasive techniques [33,34].
In the literature, there are few longitudinal studies focused on evaluating the use of COVID-19 prevention measures in dentistry and medical practice in general.However, our results align with those of other similar longitudinal studies.For instance, in June 2021, a study analyzed the prevalence and incidence of COVID-19 infection in dentists over a six-month period.The study's findings showed that dentists who maintained prevention measures, such as the use of personal protective equipment, had the lowest percentages of prevalence and incidence of COVID-19 infection over the six months evaluated [35].Another study published in 2022 assessed the use of biosecurity measures during dental care in preventing COVID-19 infections over a three-month period.The study's results demonstrated that maintaining prevention measures significantly reduced the rates of COVID-19 infection during dental care [36].Therefore, the results of the two aforementioned studies, along with the findings of the present study, reinforce the theory that maintaining minimum prevention measures, even after the most severe infection waves of COVID-19 could help prevent new pandemics and avoid potential COVID-19 infection outbreaks [37], which can arise from the extreme relaxation of prevention measures [38] or new virus variants that continue to emerge [39].

Limitations of the study
The study, focusing solely on El Salvador and Mexico, may not be generalizable to other countries with distinct healthcare systems or COVID-19 dynamics.Relying on a 16-question survey introduces potential biases from self-reporting and might not encompass the full scope of the topic.

Conclusions
During 2020 and 2021, in El Salvador and Mexico, a significant association was observed between dental care services and various preventive measures and protective barriers against COVID-19.Specifically, the use of phone triage, thermometers, physical distancing, and face shields showed a positive correlation with the provision of dental services in both countries.These findings underscore the importance of national public health agencies promoting the implementation and adherence to minimum safety measures in dental care, even though the most severe waves of COVID-19 have passed.All of this is to be previously prepared to deal with new pandemics or the possible resurgence of reinfection waves that have been observed when relaxing prevention measures due to the continuous presence of new virus variants.

TABLE 1 : Dental care service during COVID-19 in El Salvador and Mexico in 2020 and 2021.
Statistical test: Chi-square

TABLE 2 : Prevention measures in clinical practice during COVID-19 in El Salvador and Mexico in 2020 and 2021.
Statistical test: Chi-square.Physical distancing: space of at least one meter between patients.

Table 3
displays the use of personal protective barriers in clinical practice during COVID-19 in both countries for the years 2020 and 2021.In El Salvador, high utilization rates were noted for

TABLE 3 : Personal protection barriers in clinical practice during COVID-19 in El Salvador and Mexico in 2020 and 2021.
Statistical test: Chi-square

TABLE 4 : Binary logistic regressions for association the dental care service with the preventive measures and protection barriers during COVID-19 in El Salvador and Mexico in 2020 and 2021.
Dependent variable: dental care service.Physical distancing: Space of at least one meter between patients.OR: Odds ratios.CI: Confidence intervals.
Nepal et al. surveyed approximately 350 health professionals, including medical assistants, nurses, and doctors.Generally, the respondents demonstrated an intermediate to high level of knowledge about COVID-19 and exhibited an intermediate to moderate understanding of practices and prevention of COVID-19 infections [26].