Keywords

1 Introduction

The COVID-19 pandemic has hugely affected the health and socioeconomic status of the globe. Partial and complete lockdowns were imposed in many countries across the world to curb the spread of the virus [1]. The global education sector experienced an intense interruption of teaching and learning during this pandemic. Institutions suddenly underwent a change in thinking from an onsite to an online mode of teaching to preserve the continuity of education [2]. The eventful impact of this acute change on student education was of high-level concern [3]. Dental care providers experienced the highest professional risk for transmission on account of their proximity to the patients and using dental equipment that generates aerosol. Many dental clinics and schools were temporally shut down [4]. Dental students were particularly affected, and student training was completely ceased [5].

The dental curriculum is vast and diverse. It embodies three domains, namely academics, technical skills, and critical thinking that are delivered in an integrated manner [6]. Though the last 3 years of the dentistry course is patient-centered, the initial 2 years of training is exclusively preclinical [7, 8]. Successful accomplishment of delivery of the lab objectives mandates an ultimate prerequisite of students’ physical presence in the preclinical laboratories [9]. Strict COVID-19 protocols were implemented to protect the health and safety of students and educators thereby limiting the number of students attending dental clinics and labs concurrently [10]. Complications still exist in training the students on practical skills using the online mode of teaching as online courses provide minimal practical training content. With the long-standing situation of the pandemic, online education continues to be an integral part of teaching institutions [11]. The introduction of the community vaccination programs facilitated many universities to adopt hybrid and blended modes of teaching that involved both online and on-campus instruction. Asynchronous online learning facilitates the students to learn at their own pace and have control over their learning process [12]. However, the effect of these modes on the preclinical aspects of dental education is not thoroughly studied. Numerous studies have been conducted during the pandemic to study the dental student experience, perception, and attitude toward integrated teaching methods, however, very few studies were published regarding performance and assessments in preclinical lab training pre- and post COVID-19.

With the lockdown due to COVID-19, the College of Dental Medicine, University of Sharjah suspended all the onsite classes and labs during the second week of March 2020. Adhering to social distancing protocol, the dental clinics and labs resumed later in September 2020 with one-fourth of the capacity of students. Lectures continued to be online for the entire academic year 2020–21. Many innovative ideas were proposed for conducting the preclinical labs by hybrid and blended modes of teaching. This paper highlights the various tools used in the successful delivery of preclinical dental lab exercises to BDS students during the COVID-19 pandemic. The study aimed at comparing the student performance in the dental preclinical labs evaluated based on skills and knowledge before and after the introduction of the innovative practices by online mode.

2 Materials and Methods

2.1 Study Sample

The study was conducted at the College of Dental Medicine, University of Sharjah. All the first year and second year BDS students (n = 251) involved in the preclinical dental training were included in the study. The study consists of four cohorts. The control groups comprised the BDS1 and BDS2 students of the academic year 2019–2020 who underwent traditional methods of lab teaching before the pandemic. The other two groups consisted of students from the 2020–2021 batch who experienced online methods of delivery for the lab curriculum. Students were divided into small groups of 10–12 students each. While 2 groups attended the lab onsite, all the other groups were taught by the online modes concurrently. To ensure fair distribution, the groups were rotated every week.

2.2 Innovative Practices Followed in Preclinical Labs

Blackboard was used as the e-learning platform for delivering all online laboratory sessions and conducting quizzes and assessments to the students. Small group student engagement was performed using Microsoft Teams meetings. An education document camera from Epson (ELPDC21) was procured for tooth morphology, osteology, and anatomy demonstrations. The Epson document camera is an exclusive user-friendly, lightweight portable device with a 12× optical zoom and 10× digital zoom with a 30-frames-per-second screen refresh rate and a larger capture area (see Fig. 1). It carries a built-in LED light that illuminates and enhances the intricate details of the study specimen. In addition, it is also provided with a microscopic attachment that can be fitted to the ocular lens of a microscope. It generates full HD images and videos that can be directly shared to the computer through the USB port and to a larger display screen through the projector cable. An Olympus microscope provisioned with optical camera attachment (DP22-CU) and imaging software (cellSens) was employed for a live demonstration of histology slides (see Fig. 2).

Fig. 1
Four illustrations of Epson document camera.

Epson (ELPDC21) education document camera with a Built-in LED light to focus on object; b Height adjustment provision; c Flexible rotation facility; d Microscopic attachment (reproduced from Epson.com)

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Fig. 2
Two photographs of Olympus B X 1 4 microscopes. The objective lenses are located on the nosepiece of the microscope, the specimen is placed on the stage, and the binocular head is on the top.

Olympus BX14 microscope with DP22 optical camera attachment

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2.3 General and Dental Anatomy Labs

The ELPDC21 camera was used to demonstrate the anatomical landmarks of tooth, bones, and head and neck models. For the tooth identification exercises, both the large and life-size tooth models were used for description. The larger models were fixed in a position under the camera, and the flexible camera head was moved around the models for complete visualization of the tooth (see Fig. 3). Alternatively, for the smaller teeth models, the tooth was moved with the camera in a fixed position. High optical and digital zoom provisions of the camera enhanced magnification and the clear visualization of the occlusal details of the tooth. A step-by-step live demonstration of tooth carving was rendered to the students using the document camera. The students carved the tooth models from wax blocks simultaneously, while the teacher demonstrated every step using the document camera. The student’s work was instantly shared with the instructors by enabling the student as moderators on the Blackboard Collaborate live sessions or Microsoft Teams meetings. Comments and corrections were given to the students at every stage of the carving exercises by their respective mentors.

Fig. 3
A photograph of a tooth model under the lens of the Epson camera.

Depicting the demonstration of tooth models using the Epson education camera

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The live laboratory sessions of basic anatomy and osteology of the head and neck were delivered following consecutive online lectures. The bones and anatomy models were placed under the above-described Epson camera for demonstration of the landmarks (see Fig. 4). Intricate details of the models were shown to the students using the zoom and freeze options of the camera. In addition, color-coded models were used to enhance orientation and identification.

Fig. 4
Two photographs. 1. An anatomy model is underneath the camera lens, which is located on the flexible arm. 2. The flexible arm of the camera is at a different angle to capture the side view of the anatomy.

Depicting the demonstration of anatomy models using the Epson education camera

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2.4 General and Dental Histology Labs

With the available resources, we experimented with two online methods to live telecast the slides to the students through Blackboard Collaborate. In the first method, we used an Olympus microscope with an accessary optical camera attachment (DP22-CU) and imaging software (cellSens). During the online live sessions, the histology slides were navigated in a Z-like manner, and the whole tissue sections were shown to the students in a continuous sequence. Enhancement of the resolution and magnification of specific regions of the tissues was facilitated through the software adjustments provided with the camera attachment. Second, the Epson camera's microscopic attachment was connected to the compound microscope and the imaging was directly shared to the students using either Teams or Blackboard application. Further, these live demonstrations were also recorded for the future reference of the students.

2.5 Laboratory Assessments

The formative assessments consisted of onsite and online quizzes. To minimize multiple visits of students to the college, summative lab assessment was conducted online for anatomy and histology labs at the end of each semester. Onsite practical exams were conducted for tooth morphology. Student skills in the tooth morphology laboratory were assessed by the carving of a life-size tooth by individual students.

2.6 Data Collection and Analysis

The individual scores of all the exams, practical assessments, and quizzes conducted during the academic year 2020–21 were compiled in an Excel sheet. Similar assessment data of the students from the previous academic year 2019–20 was retrieved and tabulated. The data was presented as mean and standard deviation. The IBM SPSS software, version-28, was used to statistically analyze the data. The equality of the means was tested using the Student T-test. A p-value less than 0.05 was considered as significant.

3 Results and Discussion

The number of students was 131 in BDS1 and 120 in BDS2, respectively. Comparisons were made between the student grades of midyear practical and final practical exams of regular teaching in the 2019–2020 year and hybrid online teaching in the 2020–2021 year. The formative assessments conducted in the labs during the academic year 20–21 were also compared with the previous year's performance.

3.1 BDS1 Results

The comparison of performances among the BDS1 students showed that the scores of the midyear general histology assessments were similar in both academic years. However, the final and overall scores in the 2019–20 cohorts were higher than the 2020–21 batch students with a p-value of 0.00 and 0.001, respectively (see Fig. 5). The mean total scores of all tooth morphology summative assessments (3.43, 7.91) conducted throughout the year 20–21 were significantly higher than the scores of 2019–20 students. On the contrary, 2019–20 batch students scored higher in the tooth anatomy lab quizzes (p = 0.04). Based on the skill tests, high-quality results were recorded by the online batch of students in the carving assessments (p = 0.000) (see Fig. 6). The overall BDS1 student performance in the dental anatomy lab was reported to be significantly higher in online students compared to the regular batch students.

Fig. 5
A bar graph plots the before and after performances in general histology, by B D S students of batches 19 to 20 and 20 to 21. 1. Midyear, 70, 70. 2. Final, 78, 70. 3. Cumulative, 75, 70.

Bar graph comparing the BDS1 student performance in general histology before and after the introduction of online labs

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Fig. 6
A line graph plots students' performance in tooth morphology. Skill 19-20 to 20-21 increases from 60 to 80. Knowledge 19-20 to 20-21 ranges from 70 to 80. Overall 19-20 to 20-21 ranges from 71 to 80. The values are approximated.

Line diagram depicting an enhancement of BDS1 student performance in tooth morphology labs after the introduction of online labs

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3.2 BDS2 Results

The results of the study reveal that the performance of the BDS2 online students in dental anatomy was like the students of the previous academic year. However, they performed better in the midyear lab assessments (p = 0.003) compared to the onsite batch students. All the dental histology assessments and overall stream scores were higher in the regular batch students compared to the online batch (p = 0.001) (see Fig. 7).

Fig. 7
A bar graph presents the B D S 2 student performance in dental anatomy and histology, respectively. Batch 19 to 20, 75, 86. Batch 20 to 21, 73, 80. Data are estimated.

Chart showing a decrease in the BDS2 student performance in histology and anatomy after the introduction of online labs

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3.3 Overall Performance of BDS1 and BDS2

The overall performance of the students in all the above-mentioned labs and quizzes was compared between the academic years. BDS1 students of the online batch showed higher total mean scores (38.13, p = 0.00), while the BDS2 regular batch recorded a slightly higher overall mean score (27.96) compared to the online batch (26.84), respectively (p = 0.046) (see Fig. 8).

Fig. 8
A graph presents overall performance. In batch of 19 to 20, B D S 1, 55. B D S 2, 80. In batch of 20 to 21, B D S 1, 78. B D S 2, 78. The values are approximated.

Depicting the comparison of overall performance of BDS1 and BDS2 before and after the introduction of online labs

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Digitalization has become an inevitable part of education [5]. Many novel educational models introduced during the pandemic might sustain ahead with time [13]. The COVID-19 pandemic is prolonging with the occurrence of new mutant forms of the SARS-CoV-2 viral genome [14]. Students’ access to training labs could be limited, and social distancing protocols need to be taken forward in the future to minimize exposure among students [7]. Dental preclinical education requires physical interaction. Various alternative methods like virtual models, videos, and recorded sessions are of limited use in preclinical dental labs as it is skill-based learning [15]. Evolving strategic plans to recover the preclinical teaching for dental students without overcrowding in the clinical and preclinical laboratories is the need of the hour [7].

This study evaluated the effectiveness of online teaching of preclinical labs for dental students during the COVID-19 pandemic. Our study results suggest that compared to knowledge, skill-based student performance is enhanced with the hybrid mode of preclinical training of BDS1 students. This factor could be attributed to the small group attendance and an increased student–teacher ratio. The academic achievement of students relies on many factors, yet the student–teacher ratio plays a crucial role in student performance and effectiveness [16]. During the pandemic, the student–teacher ratio increased to 1:4 from 1:10 before the pandemic. A small class size promotes strong social interaction and thereby favors improvements in skill-based achievements [17]. Direct and virtual supervision further enhanced the students' carving skills in the tooth morphology laboratories, which was reflected in our study's results. Our results support the positive aspects of hybrid teaching, and thus it can be applicable to preclinical exercises in future as they are as effective as conventional onsite lab delivery methods.

Since the seventeenth century, cadavers were the gold standard for learning human anatomy [18]. Plastinated anatomy models, dissection videos, and three-dimensional printed (3DP) and online models are the other readily available alternatives for cadaveric dissections [19]. Our dental school employs 3D models for the delivery of anatomy and osteology labs to BDS2 students. Fasel et al. suggest that 3D models are ideal for delivering undergraduate curriculum due to their high correlation with the anatomy reality [20]. The students in the regular batch studied the models in person in the preclinical labs. However, the online batch students viewed the models in online and onsite modes. Our study results prove that the students show similar performance in anatomy labs with both the regular and online modes of learning. Attardi et al. conducted fully online anatomy labs using 3D models through Blackboard Collaborate and reported that the student performance was consistent with the previous year's students who underwent traditional teaching [21]. Wilson et al., 2018, showed that the student scores were statistically equivalent when traditional dissection methods were compared with other modes of laboratory approaches such as hybrid, digital models, and 3D models [22]. With the unprecedented future situations, creative adaptations and judicial use of technology can replace the traditional methods of delivery of preclinical anatomy labs in dental schools [23].

Traditional teaching methods for general and dental histology include didactic lectures, tutorials, and onsite microscopy involving face-to-face discussions [24]. The aim of our study was to deliver all histology teaching via online mode. During this study period, all the histology lectures and tutorials were given online for the BDS students. The histology slides were delivered through live online microscopy, and lab assessments were also conducted online by using two cameras for invigilation. The results of our study revealed that students' (both BDS1 and 2) performance was better during the traditional teaching methods compared to the online method. These results indicate that the online mode of learning histology did not produce any detrimental effect on the BDS students. However, while comparing the overall student performance in histology for the whole academic year, we can appreciate that this method did not worsen the student performance either. Earlier studies that experimented with online teaching for histopathology have exhibited either improved or similar student performance [24,25,26]. Di Giacomo 2021 reports that loss of active interaction with the teachers and peers during the online system of teaching is the biggest concern and leads to potential damage to both theory and practical dental education. The author also proposed that distance learning has greater possibilities for distraction. Lack of self-motivation and difficulties in self-regulated learning were the most common issues faced by medical and dental students during online education [5, 27]. Traditional methods of direct viewing the slides under the microscope in the labs promote interactive learning and provide thorough access to the entire tissue section [25]. With the future challenges ahead, e-learning is inseparable from the education sector. Though conventional microscopy is the benchmark for histopathologic learning, alternative and newer methods such as digital slides should be experimented with in the dental curriculum.

4 Conclusion

Dental education was crucially challenged during the COVID-19 pandemic. Distance learning was the only available adjunct that ensured the uninterrupted delivery of education. Dentistry is highly skill-oriented, and patient-centered. Rendering practical training to students through E-platforms was tedious for educators. Many dental schools implemented novel methods that assisted in monitoring preclinical performance. Adapting certain innovative online practices during our study showed a reduction in student performance in histology labs and enhanced performance in tooth morphology labs. Students exhibited marked improvement in laboratory skills with the online mode of training. BDS1 students performed better with online Lab sessions compared to BDS2 students. However, further studies are called for evaluating the effectiveness of these methods in dental education. Smooth continuity of the dental programs might demand the incorporation of digitalization in appropriate settings in future. Dental educators must explore innovative and alternative techniques to ensure high-quality preclinical training for dental students in a safe environment.