Histology, the knowledge of cellular and tissue structures at the microscopic level, is essential for dental, medical, and health sciences education. However, this branch of science is intrinsically challenging to learn [1,2]. Traditional histology teaching includes classroom lectures complemented with a microscopy laboratory component. Learners need to form an integrated mental schema of the location, structure, and function of the microscopic tissue components, which is a heavy cognitive load [1]. According to a student survey, the key features that make histology “difficult” include unfamiliar terminology, complexity of the subject, insufficient time, and inadequate photomicrographs [1].

Students studying dentistry and dental hygiene at the University of Alberta extensively study oral histology to understand the microanatomy and development of tooth and oral structures. Teaching oral histology at the School of Dentistry relies on PowerPoint presentations with images from textbooks, supplemented with light microscopy labs. One primary learning expectation is that the students recognize a given histological section and identify the underlying structural components. Students appreciate having access to more photomicrographs and practice labeling exercises to study on their own outside the class time. We created an alternate modality for students to reduce the cognitive load and time/location barriers of learning histology. We developed an augmented reality (AR) cellphone application called Dental AR (Figure 1) to help students develop mental models of cellular structures at their own pace.

Cognitive load theory explains how learning occurs and how educational technology can facilitate learning [3]. The information that we learn can be either primary or secondary [4]. Humans are evolutionarily programmed to acquire primary knowledge, such as speaking, without assistance. In contrast, secondary information requires learner’s conscious efforts and is aided by explicit instruction [5]. Learning to identify histological structures is an example of secondary information.

A critical part of learning is memory formation. Our cognitive system has a working memory with a limited capacity [5,6]. The learning load of working memory is affected by the underlying nature of the subject matter (intrinsic load) and how the topic is presented (extrinsic load). The intrinsic load is not readily changed for a given subject matter, but the learning process can be eased by changing the way the subject is presented (extrinsic load). The introduction of gamification using Kahoot in a histology course, for example, presented histology exceptionally well, stimulated learning and improved participants’ satisfaction [7]. With our Dental AR application, we hope to complement traditional teaching methods and reduce the extrinsic load by providing an alternate scaffold for learning histology.

Dental AR development was guided by Keller’s attention, relevance, confidence, and satisfaction (ARCS) model [8]. According to the ARCS model, students are more likely to engage with the study material if their attention is captured, their confidence is increased, they are satisfied with the material, and the subject’s relevance is apparent. To address the “attention” component, we developed Dental AR as a cellphone application, usable on any mobile device. Studies show that students regularly use their mobile devices for academic activities at the post-secondary level and consider these devices essential to their academic success [9]. Attention can also be gained by perceptual arousal, inquiry arousal, and variability [8,10]. Dental AR contains a collection of photomicrographs, videos, and audio that can be presented as questions to stimulate perceptual and inquiry arousal (Figures 1, 2).

When creating Dental AR, we implemented AR, a technology that incorporates digital data into the real-world space [11]. Users can use their smartphone camera to scan a target histology image and toggle to hide or display the image’s annotations (Figure 1). This allows students to use their cellphones as flashcards [12] and perform self-assessments of their oral histology knowledge. The application also includes videos that can assist in the formation of robust mental models. When an appropriate target image is scanned, a narrated video is displayed, explaining palate and tooth development mechanisms (Figure 1). Students can repeatedly interact with the material to improve their confidence. Dental AR allows students to test their knowledge in a just-in-time manner, building motivation through satisfaction [13].

Histology has always been a relatively unengaging and intrinsically challenging topic for health professional students. To reduce the extrinsic load of learning histology, Dental AR creates an alternate way to present histology to students.

Although the survey response rate was low, it is consistent with what is typically observed with surveys of this type, and students who completed the survey represented 28% of the entire cohort. According to the students, both the confidence and satisfaction components of Keller’s ARCS model were addressed using Dental AR, and this application was an effective supplement to their learning. One point of feedback from the students was that the app helped them study for only 10% of the exam questions. We hope to expand Dental AR by incorporating more target images and videos to cover more subject areas to address this concern.

The students at the School of Dentistry are required to have a computer, and all have a personal smartphone or mobile device; however, not all students are privileged to have access to this type of technology. Another possible pitfall of using this type of technology for learning is the potential for distraction by multifunctional technologies like smartphones. Interruptions by text messages, phone calls, or notifications can disrupt students’ attention and inhibit the formation of the mental models necessary for effective learning. Despite these limitations, the amalgamation of computers, AR, cellphones, and education improves student satisfaction, in-class participation [14], and academic performance [15,16]. We believe that Dental AR has a promising future in facilitating effective learning.