A Multi-Country Survey on the Impact of COVID-19 on Dentists in Latin America

Background: The COVID-19pandemic has signicantly impacted the dental sector worldwide. Methods: The impact of the pandemic on dentistsfrom Latin America was investigated by an online survey with professionals working in 11 Spanish-speaking countries in September–December 2020. The invitations were sent to registered professionals. An open campaign was promoted on social media. The questions investigated dental care routines, work practice changes, andfeelings about the pandemic, in addition toreasons for engaging in furthersurveys.Descriptive statistics were used to identify frequencies and distributions of variables. Proportions were compared using chi-square tests. Results: A total of 2,127 responses were collected from a samplewith diverse demographic, sex, work, and education characteristics. The impact of the pandemic was considered high/very high by 60% of respondents.The volume of patients assisted weekly was signicantly lower compared with the pre-pandemic period (mean reduction=14 ±15 patients). A high rate of fear to contracting the COVID-19 at work was observed (85%); 4.9% of participants had a positive COVID-19 test. The mask most frequently worn was PFF2/N95 (42%). The main professional challenges faced by respondents were reduction in the number of patientsor nancial gain (35%), fear of contracting COVID-19 (34%), and burden with or diculty in purchasing new PPE (22%).The fear to contracting COVID-19 was inuenced by the number of weekly appointments. A positive test by the dentists was associated with their reports of having assisted COVID-19 patients. The most cited feelings about the pandemic were uncertainty, fear, worry, anxiety, and stress. When asked about incentives to participating in further surveys, the most common responses were receiving articles that originated from the investigation (44%)and priority access to research data (15%). and manuscript. conceptualization, investigation, methodology, validation, data curation, and critical review of the manuscript. MRM, ADS, PGG, EF, TMM, GG, LAA, LFR, WBT: methodology in different countries, data translation, and proofreading of the manuscript. GSL: conceptualization, data curation, and critical review of the manuscript. MBC: conceptualization, validation, formal analysis, and critical review of the HHS: contributed formal analysis and critical review of the manuscript. FFD: contributed to supervision, funding acquisition, and critical review of the of considered relative and gender All their nal and

In 2020 the COVID-19 outbreak was declared a pandemic, and dental practices in several countries were closed except for emergencies [1,2,7]. Since dental care is an essential service, o ces were later reopened and have been able to remain working. Latin America has been of the most signi cant pandemic epicenters, daily accounting for thousands of new cases and deaths. Although the region is known for its large inequalities, it has not usually been the focus of studies on the pandemic impact on dentistry. A study with over 3,000 dentists, during the rst wave in Brazil, the largest country in the region, reported differences in coverage between public and private dental care networks and new clinical routines for dentists associated with an economic burden on dental practices [7]. Another study in Brazil revealed that although the evolution of COVID-19 among oral health professionals was similar to that of the general population, the cumulative incidence was 5% higher among dental personnel [13]. The scenario in other Latin American countries has not received much attention, and it would help to understand the scale and nature of the impacts on dentistry in the region. A survey with dentists and dental students from Latin American and Caribbean reported in uence of the pandemic on social, mental health, and labor aspects of dental staff [14]. In another study, dentists from Latin America and the Caribbean reported that they had assisted patients with COVID-19 more often than the rates of frequency reported for this purpose by their counterparts in Europe [15].
A signi cant challenge in the ongoing pandemic has been to reach participants willing to engage in clinical or epidemiological research as social distancing is still an effective measure for reducing the chances of contracting COVID-19 [16]. As a result, a pandemic of online research has been described, with methodological issues that have sometimes been overlooked by researchers [17]. The overload of online questionnaires may reduce the interest of potential participants and instigate further challenges to online research. In the present study, the impact of COVID-19 pandemic on dentists in Latin America was investigated by means of an online survey with professionals working in 11 Spanish-speaking countries in the region. The questionnaire investigated professional practices and dental o ce routines during the pandemic, including COVID-19 contraction rates and respondents' feelings about the pandemic. In addition to questions on dental care routines, participants were asked about their previous participation in online surveys, the reason for engaging in the present study, and potential incentives to taking part in future research.

Study design and ethical aspects
This multi-country cross-sectional survey was implemented in 11 Spanish-speaking Latin American countries between September and December 2020. The participating countries were Bolivia, Chile, Colombia, Dominican Republic, Ecuador, Mexico, Nicaragua, Paraguay, Peru, Uruguay, and Venezuela. The study protocol was approved by an institutional research board from each participating country. All research methods were performed in accordance with the Declaration of Helsinki. The primary objective of the survey was to assess the impact of COVID-19 pandemic on the dental care routines and associated aspects. A questionnaire that had been developed and pre-tested in a previous study [7] was translated to Spanish, adapted to, and pre-tested again for the present investigation. The respondents had to agree with their participation to access the questionnaire, and were directed to print or save the rst page of the questionnaire to retain a copy of the informed consent form. Questionnaire development and pre-testing A self-administered electronic questionnaire was designed to provide data on possible changes in clinical routines and the behavior of dentists during the pandemic. Detailed description of the original questionnaire development can be found elsewhere [7,19]. For the present study, the questionnaire was translated into and adapted based on the inputs of at least four researchers in three rounds of discrete reviews. The questionnaire was hosted on Google Forms (Google Inc., Mountain View, CA, USA) and pretested using a sample of 35 dentists from all the 11 participating countries. There were differences in sex, age, working sector, experience, and education levels across the pre-testers, who evaluated reliability and face validity, writing, and internal consistency. The pre-testers scored the clarity of each question between 1 (not clear) and 5 (very clear) on a Likert scale and were able to explain their scores. No questions were rated with scores 1 or 2; questions rated with at least one score 3 (n = 9) were discussed by three or more researchers and edited based on the pre-tester comments. The average ± standard deviation (SD) scores were 4.77 ± 0.09 for the 9 questions requiring revision and 4.86 ± 0.09 for all 32 questions. The pretest was important for the purpose of including other response options, which helped with reducing response bias. A nal revision of the questionnaire was carried out iteratively. Pre-testers were excluded from the de nitive study.

Questionnaire content
The initial section of the questionnaire contained the title and main objective of the study, an invitation was extended only to dentists to participate and to complete the questionnaire only once. Informed consent was provided in the second section, in which the participants were noti ed that their participation was voluntary and not paid, potential risks and bene ts were informed, and they were assured that all responses would be treated con dentially and anonymously. The questionnaire contained 32 mandatory items (1 open, 31 close-ended questions) divided into four sections (screens): demographic and professional pro le (n = 11); professional practices during the pandemic (n = 10); structure and routine of the respondent's main workplace (n = 7); and a nal section (n = 4) addressing the respondent's feeling about the pandemic, previous participation in online questionnaires, and incentives that could motivate them to engage in future online research. No randomization of items or adaptive questioning methods were used. The responses could be reviewed by using back buttons before submitting the form. The main outcomes were related to the professionals' behavior regarding their clinical routines. The options 'I'd rather not say', 'I don't know how to answer', and 'Does not apply' were available to avoid response errors.
In an open question, the respondents were asked to use a single word to describe a feeling that they would associate with how they felt during the COVID-19 pandemic.
Sample selection, sample size estimation, and collection of responses All dentists practicing in the 11 Latin American countries were eligible. Researchers from each country contacted local national dental councils to enable the number of registered practicing dentists to be estimated. Given a rough estimation of a target population of approximately 300,000 professionals, we estimated that ~ 1529 responses would be necessary to ensure a 95% con dence interval and 2.5% margin of error. The sample was, however, not expected to be representative of each country but rather to provide a general overview of the impact on dentistry in the region. Responses were collected between September 22 and December 13, 2020.

Participant recruitment and survey administration
The strategy for recruiting participants began with emails or WhatsApp messages being sent to registered dentists and, later, included an open social media campaign targeting dentists in the participating countries. Survey administration was the same irrespective of the mode of invitation since all led the respondent to a unique website link. We tested whether the questionnaire could be read well on different computers, tablets, and cell phones. The e-mail and WhatsApp messages were sent via professional dental/health entities or researchers based in each country, and contained a brief statement that included the study objective, the average response time (7 min), and the website link to the questionnaire.
Reminder emails and messages were sent after at least two weeks. The open social media campaign followed a similar approach to that previously reported [7,19] and included invitations posted by the research team on Facebook, Instagram, and/or Twitter social networking services. Dentists with professional social media pro les from the 11 participating countries were asked to extend the promotion and contribute to divulging the invitation in their own social media pro les. Data analysis Partial questionnaire completion was not possible. In some questions, the responses were restricted to a speci c population, e.g., only dentists assisting patients at the time the survey was responded. The responses 'I'd rather not say', 'I don't know how to answer', and 'Does not apply' were considered missing data, resulting in variable numbers of respondents for different questions. Descriptive statistics were used to identify frequencies and distributions of variables. Proportions were compared using chi-square tests. The numbers of weekly patients assisted before and during the pandemic were analyzed using a paired t-test with unequal variances. All analyses were performed in Stata 14.2 (StataCorp, College Station, TX, USA). Words used in the open question about the feeling associated with the pandemic were translated to English. Singular and plural words, lowercase and capital letters were grouped together.
Nouns and adjectives also were grouped for consistency, e.g., anxious/anxiety. The decision was to keep either the noun or adjective considering the most frequent form used.

Results
A total of 2,217 valid responses were received with no atypical timestamp observed. The response rate was ~ 3.2% considering email invitations only, but the numbers of dentists reached, rejections, and losses could not be calculated precisely because different means were used to recruit participants, including a social media campaign. Table 1 presents the demographic and work practice characteristics of the respondents. The study recruited participants from all of the 11 countries, the respondents were of a mean age of 38 ± 11 years, the majority were female (76%), and had been in dental practice for up to 19 years (74%). Most respondents claimed that they worked in the private sector (81%), while the most common postgraduate education they had completed was residency or advanced special training (39%). Impact of the pandemic on work routine and behavior of dentists The volume of patients assisted weekly compared with the pre-pandemic period was reported to be reduced by 88% of the respondents, including 5.6% that were not seeing a single patient in the period. Interestingly, 6.1% of the sample reported increased volume of patients during the pandemic. Before the pandemic, the mean ± SD of weekly appointments reported was 25 ± 22 (median = 20), whereas during the pandemic the mean was 14 ± 15 (median = 9), with a signi cant difference between the two periods (P < 0.001). The impact of the pandemic on work routines was considered high or very high by 60% of respondents. In total, 46% of the participants reported having had online patient appointments during the pandemic, whereas 39% were not willing to conduct online appointments, and 7% reported an overall negative experience this format. Although 85% of respondents feared contracting the COVID-19 at work, only 17% indicated that they had been tested for the disease, with 4.9% reporting a positive test. The masks most frequently worn by respondents when assisting patients were PFF2/N95 (42%), disposable surgical mask (27%), and surgical mask on top of PFF2/N95 (21%). The three main professional challenges faced by respondents were reduction in the number of patient appointments or nancial gain (35%), fear of contracting COVID-19 at work (34%), and burden with new PPE or di culty in purchasing PPE (22%).
As shown in Fig. 1A, the number of weekly appointments was associated with how prepared the dentists reported themselves to be to assist patients with con rmed COVID-19. The fear to contracting COVID-19 at work was also in uenced by the number of appointments (Fig. 1B): professionals assisting more patients a week, more often reported that they had no fear of contracting the disease, than dentists who were seeing fewer patients. The number of weekly appointments, however, was not associated with the report of having assisted COVID-19 patients (Fig. 1C) or with positive COVID-19 testing by the dentists themselves (Fig. 1D).
No signi cant association was observed for positive COVID-19 testing by the dentists and how prepared they reported themselves to be to assist patients with COVID-19 ( Fig. 2A). In contrast, a positive test by the dentists was associated with their reports of having assisted COVID-19 patients (Fig. 2B). Moreover, the clinical experience of the respondents (years in practice) in uenced their report on the main professional challenges they faced during the pandemic (Fig. 3). Burden with the use of new PPE or di culty in purchasing PPE was more often reported by professionals with 30 or more years in practice, whereas reconciling work with household chores was more common for professionals with an intermediate number of years in clinical practice. In the question asking respondents to cite a single word that they associated with how they felt during the COVID-19 pandemic (n = 2,121), 235 different words were quoted. The top 5 most cited were uncertainty (17%), afraid (13.1%), worried (6.8%), anxiety (6%), and stress (4.6%). The 50 most frequent words are shown in a word cloud in Fig. 4.
Engagement with the online survey Table 2 presents results related to questions on the engagement of the respondents in the online survey. The majority of respondents reported that they received WhatsApp messages or email invitations to contribute to the survey (81%). Facebook and Instagram social media services accounted for 18% of the invitations received by respondents, whereas Twitter was hardly reported as a means of invitation (< 1%).
Dental or health professional entities (35%), a fellow dentist (35%), or a professor/investigator (19%) were often reported as being sources of the invitations. The reasons most often reported by participants for deciding to engage in the survey were to contribute to their country or dentistry (55%) and because they believed in science to generate knowledge about the pandemic (24%). The present survey was not the rst questionnaire about the pandemic responded to by 20% of the participants in the present survey.
When they were asked about incentives that could motivate them to participating in a second phase of the study, the most common responses were receiving articles that originated from the investigation (44%), no incentives were needed (24%), and priority access to data from the rst phase (15%).

Discussion
This multi-country survey provided evidence on the impact of the COVID-19 pandemic on dental practice in Latin America, a region that has seldom been the focus of studies on the topic. Responses gathered by the end of 2020 from dentists practicing in 11 Spanish-speaking countries showed a signi cant reduction in the number of patient appointments and a high impact of the pandemic on clinical routines. Vaccines were still not available in the region at the time the study was conducted. As of June 2021, the proportion of fully vaccinated persons in the countries surveyed varied widely from 0-47% [20]. Considering the 11 countries in this study altogether, the average of the fully vaccinated population was 12% (median = 6.4%). Thus, although dentists and other healthcare professionals may have been prioritized for vaccination, there may still be a signi cant impact in place on the dental sector in the region.
Respondents reported that the lower volume of patients and fear of contracting the disease at work, were amongst the main professional challenges they faced during the pandemic. These two variables were found to be associated, i.e., more patients were assisted by professionals who had less fear of contracting COVID-19. By using the reported number of patients assisted before and during the pandemic, approximately 23,000 patients per week could have been missing dental appointments when considering this sample of respondents. If one assumes that the mean reduction was similar for other dentists in the countries surveyed, the overall gures of missing appointments would be overwhelming. However, care should be taken when extrapolating these ndings, especially in a turbulent, quickly changing pandemic scenario. This study was conducted in the last quarter of 2020 and 85% of participants reported fear of contracting COVID-19 at work, which was similar to the 90% fear rate reported on May 2020 in Brazil [7], when the pandemic was just starting in Latin America and several countries around the globe faced lockdowns. It is noteworthy that these two studies used the same questionnaire, which was adapted to the present investigation. The present ndings suggest that interval of 4-7 months between the survey in Brazil, the largest country in the region, and the present study were not enough to change the high rates of fear associated with working in Latin American dental o ces. By comparison, COVID-19 patients had been seen by 5.3% of respondents in Brazil in May 2020, whereas this rate rose to 15% in the present survey, a difference that is likely to be explained by the escalation of the contagion curve in the meantime. As of June 2021, Latin America is still a signi cant pandemic epicenter. In the rst 6 months of 2021, the number of deaths by COVID19 in all Latin America was higher than in 2020 [21]. Brazil has recently recorded the sad mark of 500K deaths related to COVID-19, registering a 14-day moving average of 2,058 deaths per day between June 7-20, 2021 [21]. Furthermore, in June 2021, the total death toll in the 11 countries surveyed surpassed the sad gure of 600K deaths [21].
The prevalence of dentists who tested positive for COVID-19 was 4.9%, which was higher than the 2.6% rate reported in a cumulative analysis between June and November 2020 in the USA [22]. In October 2020, another survey in the USA reported that 3.1% of dental hygienists have tested positive or been diagnosed with COVID-19 [23]. In contrast, a study conducted in Italy between December 2020 and January 2021 reported a much higher prevalence: 10.9% of the surveyed dentists reported to have had COVID-19, and 55% have had at least one family member or friend with the disease [24]. The survey in Italy [24] also showed that 82% of the dental care providers had a positive intention to be vaccinated against COVID-19, whereas 18% had a negative intention. Vaccine hesitancy also has been observed among dental and medical undergraduates in the USA in a study suggesting the need for school curricula to enhance student knowledge about vaccines [25]. Increasing vaccination rates in Latin America should be seen as the best alternative to mitigate occupational risks associated with COVID-19 in dentistry. A recent study in the UK addressing COVID-19 seroprevalence and response to vaccines in dental care professionals suggested that natural infection alone is unlikely to generate durable herd immunity, and showed that vaccination was associated with an antibody response indicative of immunological memory [26].
Positive COVID-19 test reported by the dentist was not associated with the weekly number of patients seen by the professional, which could suggest that preventive measures in o ces and PPE use have been effective in preventing contamination. Roughly two thirds of participants indicated that PFF2/N95 were the masks most often used, a relatively low prevalence because PFF2/N95 masks offer better protection than surgical masks, and the dental o ce is a high-risk environment. The low level of use could be linked to di culties in purchasing PPE and burden-associated discomfort with their use, as mentioned by 22% of the respondents. However, a positive test was associated with the report of having assisted one or more patients with a diagnosis of COVID-19. This nding could be related to the risk of infection by SARS-CoV-2 in the clinics, however, at the same time, related to a higher prevalence of COVID-19 testing among professionals that have assisted patients with the disease. Massive testing has been at the center of discussions to control the spread of SARS-CoV-2. Varied molecular and serologic assays have been developed and implemented worldwide, but there has been variability in quality and accuracy across different tests [27]. The respondents of the present survey were not asked about which test they relied on for a positive diagnosis, and it is known that the highly accurate reverse transcription polymerase chain When respondents used a single word to refer to their feelings about the pandemic, a massive prevalence of bad feelings was observed. To the best of our knowledge, this is the rst study to use this type of approach to create a picture of how dentists feel in the ongoing pandemic. The scenario of case and death counts attributable to COVID-19 in Latin America and the absence of vaccines at the time the survey was carried out may explain why uncertainty topped the list of feelings cited, followed by other associated feelings including fear, worry, anxiety, and stress. Phycological issues in healthcare workers have been the scope of several studies since the pandemic was declared. A study during a lockdown period indicated substantial psychological burden among dental personnel in terms of fear of being infected or infecting others, with a higher impact on females and less experienced clinicians [11]. Health professionals were reported to be at high risk of incurring burnout conditions during the COVID-19 emergency [29]. An investigation suggested that raising the psychological resilience of healthcare professionals should address their quality of sleep, positive emotions, and life satisfaction [30]. The importance of investing resources in research, prevention, and treatment to promote mental health of healthcare professionals has been debated [31] in addition to facing the long-term mental health consequences of the outbreak [29]. Since vaccines were not available in the region in the period when the survey was implemented, further investigation could evaluate how vaccination has in uenced the presence of fear in dental o ces throughout Latin America.
This study has limitations that should be acknowledged, including the self-selection bias, in which individuals were free to accept or not to participate in the survey and researchers could not control the self-selection process. This could lead to a higher chance of recruiting dentists who were more concerned with the pandemic or more willing to cooperate with sanitary measures. However, only 1% of respondents indicated that their decision to participate in the survey was attributable to being afraid of contracting the disease, whereas over 55% indicated that contributing to their country and dentistry were decisive for their acceptance. In addition, self-reported responses about the number of patients assisted before the pandemic could be in uenced by recall bias, meaning that the memories could be affected by posterior events and experiences. Therefore, care should be taken when extrapolating these ndings. A strength of the study was that a large sample of dentists were recruited from a region that is still struggling to deal with the pandemic, while their motives for engaging in the survey were simultaneously investigated.
WhatsApp and email invitations accounted for over 80% of the participation, suggesting that these are important tools in contemporary online surveys. Over 65% of respondents claimed that receiving scienti c articles originated by the current investigation, priority access to data generated in the research, or partial reports on the progress of the study could be incentives to engage in future research. These aspects could be addressed in further studies considering that online research is likely to continue being a frequent resource while the pandemic lasts.

Conclusions
This study collected the responses of 2,127 dentists practicing in 11 Spanish-speaking countries in Latin America in the last quarter of 2020. The results indicated a high impact on the number of patient appointments and clinical dental care routines. The self-reported prevalence of positive COVID-19 tests seemed to be low in the sample (4.9%), which reported a high prevalence of fear of contracting the disease at work (85%). The number of weekly appointments was associated with how prepared the dentists reported that they were, to assist patients with COVID-19, and their fear of contracting the disease. The massive prevalence of bad feelings expressed by the respondents was associated with the pandemic. Di culty in purchasing and burden of use of new personal protective equipment were frequent professional challenges faced by the dentists. Further investigation on how vaccination will impact the dental sector in Latin America is warranted.

Consent for publication
Not applicable.

Availability of data and materials
The datasets generated and/or analyzed during the current study are available in the Open Science Framework repository, https://osf.io/dnbgs/.
Competing interests Figure 1 Graphs showing associations between the number of weekly patient appointments and A) how prepared the dentists reported themselves to be to assist patients with COVID-19; B) fear of contracting the disease at work; C) providing dental care assistance to COVID-19 patients; and D) positive COVID-19 testing by the dentists. Signi cant associations were observed in A and B.

Figure 2
Page 23/25 Graphs showing associations of positive COVID-19 testing by the dentists and A) how prepared they reported themselves to be to assist patients with COVID-19; B) report of having assisted COVID-19 patients. A positive association was observed in B.  Word cloud showing the 50 most frequently mentioned words that the respondents associated with how they felt during the COVID-19 pandemic. The larger the font size, the more often the word was mentioned.

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