Impact of COVID-19 pandemic on using dental radiography

INTRODUCTION

The COVID-19 pandemic affected the world and changed all healthcare services. The dental practice had a higher risk of cross-infection compared to many medical disciplines due to droplets and aerosols.^[1] Infection control protocols were published in dentistry and oral maxillofacial radiology applications specific to COVID-19 disease.^[2-4] It was ordered that intraoral radiography should not be used as much as possible due to aerosol production, and extraoral radiographs should be preferred instead of it.^[1,5] While the use of radiography may be needed in the diagnosis and treatment planning of urgent cases,^[2,6] the limited use of intraoral radiography makes it difficult to reveal the clinical problem. The basic principle in the imaging request is to clarify that clinical evaluation is insufficient for definitive diagnosis and treatment planning.

Articles presenting a strategy for the practice of oral and maxillofacial radiology during the COVID-19 pandemic are very limited^[2-4] and clinical data on changes in radiographic procedures were not presented.

The purpose of our study was to analyze using dental radiography by evaluating and comparing the frequency of radiographs of patients admitted to a university dental hospital and the characteristics of the patients during the COVID-19 pandemic time points reflecting changes in the course of the disease in 2020.

MATERIALS AND METHODS

This study was approved by the Ethics Committee of Ankara Yıldırım Beyazıt University (2021–68). We planned a retrospective study that included adult patients who applied to Ankara Yıldırım Beyazıt University Faculty of Dentistry.

We collected data at three different time intervals. These periods were:

• T1: The 3 days of the month when the first official COVID-19 case was announced in Turkey, several restrictions were started, and when our hospital’s adaptation process begins to improve (March 23–25, 2020).

• T2: The 3 days of the month when the number of cases decreased in Turkey and the restrictions were eased with gradual normalization (June 1–3, 2020).

• T3: The 3 days of the month when the number of COVID-19 cases increased again (second peak in Turkey) and tighter restrictions started (November 1–3, 2020).

The data of the study group were obtained from electronic hospital records. Patients with inadequate radiographic image quality and patients under the age of 15 were excluded from the study. Patients with a full diagnostic record were included in this study.

Patients’ age and sex and dental clinical and radiographic procedures provided (on the day of their application to the hospital at T1, T2, and T3) were noted and their panoramic, intraoral, and Cone-beam computed tomography (CBCT) radiographs were examined. Each image was evaluated after blinding each reviewer from the other. Radiographic findings were evaluated according to eight subcategories: Caries (primary/secondary), pulp-related caries, periapical infectious lesion, periodontal disease, pericoronitis, crown/cusp/root fracture, impacted teeth, and others (such as cyst, tumor, jaw fracture, periimplantitis, and temporomandibular disorder findings). For this study, common causes of dental urgency^[7] were considered when creating these categories. The radiographic diagnosis was made by the consensus of three dentomaxillofacial radiologists (EYK, ZBA, and B.Ç).

The dental clinical procedures included invasive dental procedures (aerosol and/or non-aerosol generating) and non-invasive procedures (prescription/advise/no dental procedure). We did not categorize dental treatments as aerosol and/or non-aerosol generating because the procedures that produce aerosols were not clear.^[8,9] The items of invasive treatments provided were classified into six main treatment areas: Restorative, endodontic, surgical prosthetic, periodontal treatments, and other surgical procedures. Orthodontic urgencies were not included in the study because we cannot see the records of orthodontics and pedodontics clinics in the electronic hospital software program.

RESULTS

DISCUSSION

The incidence of patients who had a radiographic procedure was the lowest at the beginning of the pandemic and significantly increased over time. The frequency of patients who had a radiographic procedure was higher (46.6%) at T3 than at T2. Using radiography increased when the number of COVID-19 cases increased. It can be said that the course of the disease did not affect use of radiography by dentists. It can be explained as an adaptation of the dentists to the new pandemic conditions.

Intraoral radiography was the most used radiographic technique before the COVID-19 pandemic^[10-14] because it has a lower radiation dose and higher image quality than panoramic radiography. It continues to be superior to other radiographic methods in the diagnosis of proximal caries and endodontic treatment planning.^[15] Although American Dental Association issued interim guidance recommending avoiding or reducing intraoral radiography when the COVID-19 pandemic begins,^[16] MacDonald et al.^[2] created a flowchart to guide the prescription of radiographic procedures during the recovery phase of the COVID-19 pandemic. In this flowchart, they recommended that if the patient who needs radiography is infected or suspected infection with COVID-19, only urgent treatment should be performed, and the first imaging method should be panoramic radiography. They suggested providing conventional dental procedures for patients without or suspected COVID-19 infection and the use of conventional radiography including intraoral radiography as the initial imaging modality if the patient does not have a gag reflex. However, these recommendations are prepared to be used in the recovery phase of the COVID-19 outbreak. It cannot be said that the epidemic was in the recovery phase since vaccination was not yet started in Turkey during the periods included in the study. In addition, considering the possibility of people infected with COVID-19 being asymptomatic,^[17] dentists should treat each patient as an infected or suspected case, as a basic principle of contamination prevention.

Dental panoramic radiography became the star of dental imaging during the COVID-19 pandemic because of its advantages such as having a lower radiation dose compared to full-mouth periapical radiography and CBCT, no gag reflex, and no aerosol formation^[18] but it was difficult to manage urgent treatments using panoramic radiography because it was insufficient to diagnose periapical pathology and pulp-related caries^[15] The main areas of using panoramic radiography are clinical suspicion of teeth with periapical pathology, the presence of partially erupted teeth, clinically evident caries lesions, swelling, and clinically suspected unerupted teeth.^[6]

Recently, conventional panoramic devices have been developed and panoramic machines with extraoral-bitewing functions have been introduced to the market. The extraoralbitewing function of a panoramic device has an orthogonal view and provides better visualization of the interface contacts of the teeth compared to conventional panoramic radiographs.^[19] The popularity of the extraoral-bitewing function of a panoramic machine increased during the COVID-19 period and it was discussed to replace intraoral radiography^[2,19,20] and suggestions were presented to improve image quality.^[19] However, according to the results of the previous studies, it was contradictory that it was superior to intraoral radiography for caries diagnosis.^[21-23] Dave et al.^[24] implied that avoidance of using intraoral radiography was inappropriate during the pandemic because the advantages of intraoral radiography cannot be ignored.

According to our results, using CBCT did not increase over time. CBCT indication can be summarized as the situations in which conventional radiographic imaging is insufficient for diagnosis and treatment planning. It should not be an alternative to intraoral radiography due to its high radiation dose.^[24] The analyses of our study were consistent with the nature of the use of CBCT.

As shown in studies,^[8,10,25,26] patients mostly apply for dental pulpal or periapical lesions and cellulitis or abscess during the COVID-19 period. The most common radiographic findings were found as caries related pulp (66.8%), caries (41%), periodontal disease (36.9%), and periapical infectious lesion (30.5%) during overall pandemic time points on average in this study. Considering that the radiographic findings also reflect the reasons for admission to the hospital, these results were compatible with other studies.^[8,10,25,26] While our results showed that periodontal disease increased gradually from 9.1% (at T1) to 45.7% (at T3) and caries gradually increased from 4.5% (at T1) to 50.2% (at T3). This may be related to the disruption of dental treatments due to the pandemic and patients’ need for these treatments was gradually increasing. We should also point out that, since intraoral radiography was rarely used during the COVID-19 period, the radiographic findings reported in our study were limited by the diagnostic ability of panoramic radiography.

The results of this study demonstrated that non-invasive treatments were higher than invasive treatments. Since no urgent triage clinic was established in our hospital and every applicant was accepted for dental interviews, the number of cases requiring urgent dental treatment was not clear. Although invasive dental treatments increased gradually during the pandemic process, dentists did not use radiography in 28% of patients who underwent invasive treatment. Since it took time for the hospital to establish a suitable environment by taking infection control measures in the early days, the interventions changed over time. Surgical and prosthetic procedures were found as the most common treatments among invasive dental procedures. The number of prosthetic treatments was highest at T1 because, at the beginning of the pandemic, unfinished prosthetic treatments were completed. The surgical treatments increased gradually over periods and most tooth extraction was performed. Restorative treatments (12.7%) and other surgical procedures (4.19%) were rarely performed and endodontic and periodontal treatments were extremely infrequent (fewer than 2%). It was recommended to extract the tooth causing severe pain to reduce the risk of infection, shorten the treatment period, and minimize re-visits.^[27] Restorative treatments were applied mostly by an excavation of caries using handpieces, and by restoration with temporary fillings or glass ionomer.

The results of the study showed that the dentists avoided the use of radiography in elderly patients and the use of radiography in the aged 65 and over patients was found to be lower than in those aged 64 and under. Measures were taken to ensure that the time spent by the elderly patients who were a high-risk group and had a curfew, in our hospital was as short as possible. The incidence of male patients was found to be higher than females at T1 and T2. In a study evaluating the attitudes of dental patients toward the Mers-A virus, women were found to be more anxious about infection than men.^[28]

Limitations of this retrospective study include a lack of clinical variables because the reasons for patient admission were not included in the hospital’s software. The causes for the patients’ admission to the hospital should be noted; however, according to the results of our study, 98% of the patients who had radiographs showed radiographic findings of common dental urgency cases.

CONCLUSION

The rate of patients undergoing dental radiography was strikingly the lowest at the beginning of the pandemic. Later, a significant increase was found over time. The course of the COVID-19 disease did not affect using dental radiography because it was higher at the time when the COVID-19 cases increased than when the cases decreased. The use of dental radiography in elderly patients was found to be less than in younger patients during the COVID-19 period. Invasive treatments applied to the patients who had radiographs were significantly higher than those who did not. This study demonstrated the changes in radiographic procedures of dental patients at different times of the COVID-19 pandemic.