COVID‐19 and dental workers: The Italian Society of Periodontology and Implantology (SIdP) survey – Nicola – – Oral Diseases

1 INTRODUCTION

Newly emerging virus diseases have become a major public health threat around the world in recent years. In December 2019, the first cases of an unknown disease were reported in Wuhan, China. The causative agent was identified to be a coronavirus species, SARS-CoV-2, which can promote a clinical condition that was named on January 12, 2020, by the World Health Organization (WHO) Coronavirus disease 2019 (COVID-19)(WHO, 2020). The main clinical characteristics in humans are highly heterogeneous with a plethora of clinical manifestations, from asymptomatic (never symptomatic or mild symptomatic) infection to severe disease with respiratory and multi-organ failure and death. Globally, as of July 19 (2021), there have been more than 190.000.000 of confirmed cases, including 4.000.000 deaths, and Europe results the second macro-area for number of cases, behind Americas. Italy was the first country out of Asia to be involved in the outbreak of the pandemic; currently, more than 4000000 cases were detected (WHO, 2021) resulting from the very beginning in a lockdown in a bid to stop the virus from continuing to spread and to mitigate the impact on society. Indeed, the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) throughout the world has been extremely rapid, suggesting the hypotheses of a crucial role played by those infected persons who remain asymptomatic even if contagious (Buitrago-Garcia et al., 2020). The main transmission dynamics is owing to the airborne in both asymptomatic and pre-symptomatics (Clementini et al., 2020; Kissler et al., 2020; Prather et al., 2020). Small virus-containing droplets (5–12 micro) and aerosols (<=5 micro) from infected people are transmitted into the environment through breathing, speaking, and coughing (Kutter et al., 2018) and also by touch of contaminated surfaces and eventually transfer viral fragments/particles to their mucus membrane (Barbato et al., 2020).

In many epidemics, healthcare workers (HCWs) have been reported to be at increased risk of occupational infection and have been suggested to be a source of onward transmission to other HCWs, patients and within their community. The latter tendence was observed also for early reports of COVID-19, where the incidence of infection was higher in HCWs than the general public (Nguyen et al., 2020; Rudberg et al., 2020; Zheng et al., 2020).

For what concerns the dental community, a recent piece of evidence claims that the prevalence of COVID-19 among US dentists as of June 2020 (i.e., first wave of pandemic) was 0.9% (95% confidence interval, 0.5–1.5) (Estrich et al., 2020); the latter figure was comparable to those coming from other countries, such as China (1.1%) (Lai et al., 2020) and the Netherlands (0.9%)(Kluytmans-Van Den Bergh et al., 2020).

The outbreak of COVID-19 has also adversely affected the lives of people in different ways such as economy, global health, and human live as a whole. In fact, It is widely discussed that the pandemic has forced countries to adopt lockdowns, quarantines, and restrictive measures, contributing to worsen the world economy, inducing long term negative effects even in the recovery period (Wei et al., 2021). Furthermore, given the high level of contagiousness, almost every country has adopted different containment measures such as physical distancing, cases isolation, quarantine, and contact tracing according to the infected population and number of deaths. The latter have caused fear, frustration, anger, and long list of complex negative emotions (Fiorillo & Gorwood, 2020; Rubin & Wessely, 2020; Xiong et al., 2020).

Trying to understand pandemic is key for dental teams, as is the need to put strategies and protocols in place for treating patients and protecting healthcare workers while vaccination programs are being developed. In this perspective, several critical issues characterize the dental setting in terms of occupational risk for COVID-19 outbreak. Droplet generation, during routinely operative procedures, comprises spatter (>100 μm in diameter), “droplet” (5–100 μm in diameter), and “aerosolized particle” (<5 μm). These droplets reach the highest concentration within 0.6m around the patient, that at the light of the proximal working distance during dental practice, heighten the potential contamination risk suffered by the dental workers (Leggat & Kedjarune, 2001; Pierre-Bez et al., 2021). Until the date, despite Italy was the first country in Europe to be overwhelmed by the COVID-19, sparse information is available on the effect of the pandemic’s breakthrough among dentists in different geographic area of Italy. A recent piece of evidence quantifies the SARS-Cov-2 antibody prevalence in a sample of dentists, dental hygienists, and other personnel employed among the dental staff in Lombardy region. It shows that the prevalence of infection was around 10%, in line with estimates on other healthcare professionals (Gallus et al., 2021).

For such background, the present investigation aims to evaluate the proportion of COVID-19 infections among a population of Italian Dental workers (Dentists, Dental Hygienists) across different geographical area of Italy. Furthermore, the impact of both the preventive measures/strategies adopted by dental offices and the psychological influences that pandemic had on the dental private practice were also analyzed.

2 MATERIAL AND METHODS

The current descriptive cross-sectional survey was administered with a web-based form from January 13 through February 20, 2021, during the late phase of second “wave” of COVID-19 pandemic in Italy. For the preparation of the present analysis, we followed the STROBE guidelines for cross-sectional studies(von Elm et al., 2014). To be eligible for the study, participants had to be 18 years or older and to be part of the following working categories: Ordinary and Active Members of the Italian Society of Periodontology and Implantology (SIdP), dentists, dental hygienists (both dental office owner and collaborator were admitted).

A digital inform consent was signed before participants starts to fulfill the 23-questions survey that was designed for the current research. Study participants were categorized in the following geographic areas: Northwest (Piemonte, Liguria, Valle d’Aosta), Northeast (Lombardia, Veneto, Friuli VG, Trentino Alto Adige), Center (Toscana, Emilia-Romagna, Marche, Lazio, Abruzzo), and South and Island (Campania, Basilicata, Molise, Puglia, Calabria, Sardegna, Sicilia). The survey subministers were articulated in six different sections. Demographic section included age (categoric variable), current professional status, and number of dental chairs per dental office (continuous variable). COVID-19 prevalence based on self-declaration was identified according to information organized as SARS-CoV-2 experience for the individual, the dental office team and for the patients; they were turned into a positive answer in relation to a positive result after any SARS-CoV-2 tests available. The survey also asked for information regarding a positive case of the dental staff after direct contact with a positive patient. According to the time span, the survey was administered and the Italian Minister of Public Health policy on vaccinations; dental workers were not vaccinated.

The second section comprises details about the source of information regarding the guidelines to adopt in the dental clinic against the spread of the pandemic and in which measure they were followed/implemented. The third section relates to the personal protective equipment that operative and administrative staff are asked to wear. The fourth section deals with the clinical strategies applied to reduce aerosol and the disinfection of solid surfaces. Furthermore, it was implemented with information regarding the changes that pandemic has induced in the organization of the dental practice. The fifth section comprises the information about performing diagnostic tests settled out by the dental office for monitoring the SARS-Cov-2 infection. The last section of the investigation was written to obtain information about the psychological state and changes in attitude during the pandemic.

3 RESULTS

A total of 790 dentists and dental hygienists answer to the web-based survey, through an original sample of 1784, with a response rate of 44.3%.

3.7 Multivariate logistic regression

The final model obtained (Figure 1) acknowledges the role of one or more contagions occurred at dental team’s stakeholder as covariates able to augment the probability to be COVID-19 positive with an OR of 3.53 and 4.76, respectively (p < 0.00). A patient with a positive diagnosis of COVID-19 demonstrates a protective role against the probability to develop an infection for the dentist/dental hygienist (OR = 0.46). The model obtained shows a Pseudo-R² of 13%.

4 DISCUSSION

To the author’s best knowledge, this is the first investigation aimed to compare COVID-19 outbreak across different Italian’s geographical area. In fact, the current web-based cross-sectional survey estimates the proportion of dentists/dental hygienists SARS-CoV-2 infected in a cohort of participants belonging to the Italian dental Community. The proportion of positive cases was in line with that of healthcare workers in Washington (U.S.A) by a molecular test (PCR) (U.S Seattle, 5.3%) (Mani et al., 2020) but significantly higher than that reported retrospectively by information derived from a molecular test (PCR) for health workers of China (1.1%) (Lai et al., 2020) and in U.S dentists (0.9%) (Estrich et al., 2020). In the latter investigation, positiveness to COVID-19 was reported to be assessed either with nasal or throat swab test, blood sample, or saliva.

According to the Italian Superior Health Institute, the number of health workers infected as of 23 of July (2021) amounted to 138.275 (ISS), representing the highest proportion in Europe. The proportion of positive tests in our experiment resulted highly heterogeneous among different geographical areas and tendentially higher in comparison with European countries. In fact, the northern part of the country experienced 2–4 times greater proportion of COVID-19-infected dental workers in comparison with the Centre/South. This tendence resembles the geographical outbreak of the pandemic observed in the general population, with a substantial gradient at the latitude levels with the highest spread in the northern regions and the lowest in the southern regions/main islands (Prezioso et al., 2020). The proportion of COVID-19 infections among dental workers observed in our experiment could be explained keeping into consideration the timing pandemic has spread throughout the country and the difference in density of population that characterizes these two different areas. As a matter of fact, Italy’s first case of COVID-19 disease was recorded in Lombardy on February 20, 2020, but recent data confirm that it was present in the north of Italy on asymptomatic individuals weeks before (Apolone et al., 2020). Furthermore, the North of Italy (Northeast and Northwest) is the richest Italian area, with the highest number of international trades, the largest number of residents, and the highest population density. Recently, Gallus and co. published a cross-sectional analysis about antibody prevalence in a sample of dental workers in Lombardy region. Lombardy remains today among the regions most hit by COVID-19 areas worldwide, in which the pandemic has killed almost 20.000 people and infected more than 400.000 (Task Force COVID-19, ISS 2020) by far the highest rate in Italy (Remuzzi & Remuzzi, 2020). The prevalence found by Gallus and co. was 10.8%, that is double as high in comparison with that obtained in our general sample (4.7%, IC 95%: 3.4–6.4) and comparable with that obtained in the Northwest area of Italy. The reason of discrepancy can be owing to the different way to assess prevalence: Indeed, seroprevalence can be considered far more accurate than a self-declaration. Comparing the previous data, it seems plausible that a considerable proportion of dentists/dental hygienists that participate to our survey were asymptomatic and so unaware of experiencing a COVID-19 infection. The role of asymptomatic/paucisymptomatic in the outbreak of SARS-Cov-2 infection was deemed to be crucial. Recently, a systematic review was conducted to assess the prevalence of people who became infected and does not experience symptoms at all (Buitrago-Garcia et al., 2020): The results show that 20% (CI: 17–25) of people were asymptomatic during infection. Moreover, half of the participants of the current experiment belongs to age categories of less than 49 y.o; epidemiologically, both the severity and the symptomatology are more pronounced in elderly (Kluytmans-Van Den Bergh et al., 2020).

Interestingly, the proportion of dental workers resulted positive after a contact with a confirmed positive patient was extremely low (0.08%, IC (95%) 0.03–2.2). The latter data seem to account for both a tangible sign of the dental setting’s safety in terms of Pandemic’s diffusion and for the high response of dental workers in terms of followed recommendations (Table 2).

In the struggle to reduce the risk of SARS-CoV-2 infection in the dental setting, the personal protection equipment most frequently adopted was the surgical masks together with filtering facepiece 2 or 3 masks (FFP2-FFP3); no differences were detected among the different area of Italy analyzed. This strategy was already described for dental settings and is in line with previous data acknowledging the protective measures adopted among dentist in Lombardy, Italy (Cagetti et al., 2020). Likewise, the concern about wearing a filtering mask was addressed in a cross-sectional on-line based survey completed by 650 dentists from 30 countries worldwide. The vast majority of the sample (84%) was aware about the importance to wear a filtered mask during the dental practice (Ahmed et al., 2020).

Considering both the high risk level of cross-infection in dentistry (Harrel et al., 1998; Szymańska, 2007), owing to aerosols produced during a variety of dental procedures, and the way of transmission of SARS-CoV-2, great attention was early dedicated to the prevention of splatters and aerosol to reduce the potential risk of SARS-CoV-2 outbreak. The most frequent strategies from our cohort were the use of natural ventilation between patients and the use of preoperatory mouthwashes (Table 3). The latter were used with high frequency throughout the whole national territory, but more consistently in the North. Evidence demonstrates, indeed, that mouthwashes have the capability to decrease the infectivity of airborne transmitted microorganisms in saliva, including SARS-CoV-2 (Muñoz-Basagoiti et al., 2021; Statkute et al., 2020); they are relatively expensive and easy to deployed in the clinical setting thus contributing to decrease the oral transmission chain. This finding is comparable with the results obtained in a survey of dentists in Lombardy (Cagetti et al., 2020), in which the majority of participants used preoperatory chlorhexidine-based mouthwashes: Interestingly, chlorhexidine resulted the most used, albeit its efficacy against SARS-CoV-2 is still debatable (Carrouel et al., 2020), and other active agents have proven their in vitro superiority (Muñoz-Basagoiti et al., 2021).

The clinical approach for aerosol limitation has also included the reduction/elimination of mechanical/rotatory instruments. The World Health Organization has recommended droplet and contact precautions when caring for patients with COVID-19 and airborne precautions during the delivery of aerosol-generating procedure (AGPs; World Health Organization Europe (WHO Europe), 2020). Contamination produced by ultrasonic scaling and air polishing was recently systematically reviewed (Johnson et al., 2021): The results obtained demonstrated that both procedures produce contamination even in the presence of suction, and that droplets take between 30 min and 1 hour to settle. As such, in the current group of participants, air abrasive devices received the higher attention, with half of the participants that, at least, limit their use during pandemic with a statistically significant discrepancy between north and south of Italy (Table 3). The usage of ultrasonic devices was also reduced asymmetrically between north and south of Italy, with almost one half of the participants that choose to apply antimicrobic solutions to supposed virulence charge. Only a reduced proportion of dental workers have completely abandoned their use.

Organization of the dental office agenda was also modified during the pandemic: Preventive measures applied have changed noticeably the timetable of the daily routine. For most participants, the time needs to cushion these changes was between 10 and 20 minutes and no additional costs were charged to the patients. The letter was homogeneous across the different geographical area, except for the Northeast, in which rate table changes were more frequent than in other regions. Dental practice re-organization seems to be mandatory for cost reducing and profitability owing to the financial distress that affects dental clinic private practice with a greater negative influences on those with higher operational costs, like those from northern area (Schwendicke et al., 2020). The dental cost fluctuation during pandemic was evaluated throughout several countries. Contrarily to our findings, Rossato and co. (Rossato et al., 2021) highlight that more than 80% of dental offices in Brazil has increased costs to overcome change of expenditure caused by pandemic emergency. The negative financial impact was also evaluated on a Likert (0–5) scale from a cohort of dentists worldwide (LG et al., 2021); the highlighted mean value for European dentists was 4.7(0.7).

Diagnostics tests were implemented on the dental practice under COVID-19 by half of the participants homogeneously throughout the whole country (Table 6): In particular, serological tests and rapid salivary antigen tests were the most used. The frequency diagnostic tests were applied, changed according to the geographical area: In south and center areas, the frequency was greater at 7 and 15 days in comparison with the other regions. Albeit dentists should be familiar with diagnostic tests options to improve the team infection control and the patient safety, some uncertainty remain on the high frequency rapid serological tests were routinely applied. In fact, rapid diagnostic tests based on antibody detection, due to the high rate of false-negative results, should not be used outside research setting, and they should not constitute the basis of a decision-making process (WHO). To prevent dental staff infections, and to ensure patient safety, molecular tests PCR based and the development of routinely screening methods like interviewing and temperature measurement still remain the most reliable methods (Tysiąc-Miśta & Bulanda, 2021).

The psychological attitude was analyzed in the last section of our survey. Results acknowledged a general positive attitude toward the pandemic outbreak, with 2/3 of the sample showing a proactive and motivated attitude irrespective to the overwhelming impact that COVID-19 has had on our life. Healthcare workers indeed were placed under additional psychological difficulties, such as the risk if being part of the transmitting disease chain and implemented workloads despite personnel reduction and uncertainty of protection equipment availability (Bielicki et al., 2020; Consolo et al., 2020). A survey conducted in north of Italy (Reggio Emilia-Modena) immediately after the first pandemic wave and involving 356 dentists, unveils that half of the participants felt lightly scared (41%) and anxious (23.6%) with 12% felt intensely sad (Consolo et al., 2020). The latter state of mind was not perceivable in our cohort, with only 5% of participants resulted concretely concerned for the future of their profession; moreover, more than 50% of participants has considered pandemic as an opportunity for concretes improvements for the dental office. This different attitude can be related to the period of the pandemic; the survey has been deployed; indeed, we asked to answer to the questionnaires at the beginning of 2021 at the end of the second wave and when vaccination process was already arranged.

The multivariate logistic regression model aimed to evaluate which was the best model to explain the probability of a dental workers to be positive to COVID-19. Interestingly, the OR of being positive was 3 times higher if at least one component of the team was diagnosed as positive for COVID-19; conversely, the presence of one positive patient was protective for the risk of being positive for the dental team (OR 0.46, CI95% 0.21–0.98). The latter result could be understood also from one side in terms of effectiveness of quarantine and social isolation that governments have issued following the pandemic outbreak and from the other with the effectiveness of preventive measures in the dental setting (personal protection equipment, distancing, and ventilation).

Current findings should be interpreted with caution with selection bias as a potential drawback of the present report. All participants, indeed, belong to a private scientific society (SIdP), and they cannot be considered representative of whole Italian dental community. Furthermore, an underestimation of the prevalence of positive COVID-19 could have occurred, in virtue of the less probability to participate of dentists that have been hospitalized or eventually have died. Moreover, owing to the web-based survey nature of the current research, our prevalence data are based only on self-declaration of positiveness, without confirming antibody testing.

5 CONCLUSIONS

The current web-based survey was conducted to determine the prevalence of COVID-19, behavioral practices, and psychological attitudes among a cohort of private dentists and dental hygienists from the members of the Italian Society of Periodontology and Implantology (SIdP) in Italy. Within the limitations of positiveness self-declaration, the prevalence of COVID-19 was 4.7% for the whole sample with a peak of 8.8% from the Northwest area of the country. Preventive clinical strategies (aerosol reduction) and personal protective equipment were homogeneously adopted among the different geographical area of the country. Despite the difficulties caused by the pandemic outbreak, dentists and dental hygienists from this sample have reacted positively and have full confidence in the future of the profession. Future research should monitor the rate of the pandemic and analyze further the risk factors involved in the spread of the pandemics at the dental office level.

CONFLICT OF INTEREST

No conflict of interest has been declared by the authors.

AUTHOR CONTRIBUTIONS

Nicola Discepoli: Conceptualization; Data curation; Formal analysis; Methodology; Validation; Writing-original draft; Writing-review & editing. Mario Raspini: Conceptualization; Data curation; Methodology; Writing-review & editing. Luca Landi: Conceptualization; Data curation; Formal analysis; Funding acquisition; Methodology; Supervision; Validation; Writing-original draft; Writing-review & editing. Nicola Marco Sforza: Conceptualization; Data curation; Investigation; Methodology; Supervision; Validation; Writing-review & editing. Alessandro Crea: Conceptualization; Data curation; Methodology; Visualization; Writing-review & editing. Francesco Cairo: Conceptualization; Data curation; Investigation; Methodology; Supervision; Writing-original draft; Writing-review & editing.