*Review* **Digital Undergraduate Education in Dentistry: A Systematic Review**

#### **Nicola U. Zitzmann \*, Lea Matthisson, Harald Ohla and Tim Joda**

Department of Reconstructive Dentistry, University Center for Dental Medicine Basel, University of Basel, 4058 Basel, Switzerland; lea.matthisson@unibas.ch (L.M.); h.ohla@unibas.ch (H.O.); tim.joda@unibas.ch (T.J.)

**\*** Correspondence: n.zitzmann@unibas.ch; Tel.: +41-61-267-2636

Received: 23 March 2020; Accepted: 2 May 2020; Published: 7 May 2020

**Abstract:** The aim of this systematic review was to investigate current penetration and educational quality enhancements from digitalization in the dental curriculum. Using a modified PICO strategy, the literature was searched using PubMed supplemented with a manual search to identify English-language articles published between 1994 and 2020 that reported the use of digital techniques in dental education. A total of 211 articles were identified by electronic search, of which 55 articles were selected for inclusion and supplemented with 27 additional publications retrieved by manual search, resulting in 82 studies that were included in the review. Publications were categorized into five areas of digital dental education: Web-based knowledge transfer and e-learning, digital surface mapping, dental simulator motor skills (including intraoral optical scanning), digital radiography, and surveys related to the penetration and acceptance of digital education. This review demonstrates that digitalization offers great potential to revolutionize dental education to help prepare future dentists for their daily practice. More interactive and intuitive e-learning possibilities will arise to stimulate an enjoyable and meaningful educational experience with 24/7 facilities. Augmented and virtual reality technology will likely play a dominant role in the future of dental education.

**Keywords:** dental education; digital dentistry; augmented reality (AR); virtual reality (VR)

#### **1. Introduction**

The implementation of digital technologies in dental curricula has started globally and reached varying levels of penetration depending on local resources and demands. One of the biggest challenges in digital education is the need to continuously adapt and adjust to the developments in technology and apply these to dental practice [1]. Most dental offices in Europe are equipped with software solutions for managing patients' records, agenda and recall reminders; recording provided services, including working time schedules; ordering materials; and managing the maintenance contracts of medical devices. These systems incorporate medical histories, digital radiographs, intraoral photographs, medicine lists, and correspondences. The systems also enable easy access to detailed odontograms showing fillings per tooth surface, restorations and carious lesions, periodontal status with visualization of the attachment level, probing pocket depth, and recession [2].

The introduction of intraoral optical scanning (IOS) allows the current anatomic situation to be digitized, enabling chairside or laboratory fabrication of restorations, to plan oral rehabilitations with a set-up [3], and/or to superimpose the situation with 3-dimensional (3D) radiography (e.g., for guided implant placement) [4]. While the penetration of these scanners in dental offices is still limited (present in an estimated 20%–25% of European dental offices) [5], laboratory scanners are presumably used by more than two-thirds of dental laboratories. The dental technician uses the 3D model files derived from IOS by the clinician or from scanned conventional casts to facilitate the fabrication of restorations. Compared to waxing, the digital design offers several advantages for quality control, such as providing data about material thickness and values of connector cross sections. While the main shortcomings of lost wax casting were erroneous castings or shrinkage cavities, with a digital workflow the laboratory benefits from improved material properties when industrially manufactured products can be used with subtractive milling or additive printing processes [6].

3D education programs have been introduced to enhance students' spatial ability, their interactivity, critical thinking, and clinical correlations with the integration of multiple dental disciplines. Augmented reality in 3D visualization allows insights in tooth morphology, and also facilitates treatment planning with fixed or removable partial denture (RPD) programs [7]. Digital technologies also include the 3D printing of virtual teeth, which has been suggested to enhance transparency for all students due to the identical setups [8].

A recent review on the application of augmented reality (AR) and virtual reality (VR) in dental medicine demonstrated that the use of AR/VR technologies for educational motor skill training and clinical testing of maxillofacial surgical protocols is increasing [9]. It was concluded that these digital technologies are valuable in dental undergraduate and postgraduate education, offering interactive learning concepts with 24/7 access and objective evaluation. A recent scoping review analyzed the application of VR in pre-clinical dental education and identified four educational thematic areas (simulation hardware, realism of simulation, scoring systems, and validation), highlighting the need for a better evidence base for the utility of VR in dental education [10]. In communicating with dental professionals, medical doctors, dental technicians, and insurance providers, dental students have to be prepared to manage digitized data, ensure patient safety, and understand the benefits and limitations of conventional and digital processes.

Overall, digitalization seems to have had a major impact on dental education, addressing various aspects, such as e-learning and Web-based knowledge transfer, but also related to diagnostics using 3D imaging and digital radiography, and practically oriented trainings in terms of dental simulator motor skills including IOS with 3D printing, prototyping, and digital surface mapping. Digital applications can provide additional opportunities to evaluate and improve education, implementing evidence-based surveys related to the penetration and acceptance of digital education.

The aim of this systematic review was: (i) to investigate the current level of implementation of digital technology in dental education; and (ii) to outline the educational quality enhancements that result from digitalization in main focus areas within the dental curriculum.

#### **2. Materials and Methods**

This systematic review was conducted in accordance with the guidelines of Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) [11]. A systematic electronic search of PubMed was performed, limited to English-language articles published between 1 January 1994 and 15 April 2020. A modified PICO search was defined for Population/TOPIC, Intervention/METHOD, and Outcome/INTEREST; whereas Comparison was omitted. The search syntax used was: ((students[MeSH]) AND (education, dental[MeSH] OR teaching[MeSH] AND digital)) AND (dentistry[MeSH] OR dental medicine). In addition, the bibliographies of all full texts selected from the electronic search were manually searched, and an extensive search of articles published in the *Journal of Dental Education* and the *European Journal of Dental Education* was conducted.

This systematic review focused on randomized controlled trials, cohort studies, case–control studies, observational trials, and descriptive studies that investigated the application of digital technologies in dental education. Reports without an underlying study design and studies not involving dental students were not included. Furthermore, the vast body of literature about the transition from glass to digital slide microscopy was also excluded. Four reviewers (N.U.Z., T.J., L.M., H.O.) independently screened the titles, abstracts, and the full texts of the identified articles to select those for inclusion in the review. Disagreements were resolved by discussion. Duplicates or preliminary reports that were followed by original publications were excluded.

#### **3. Results**

A total of 211 titles were identified by the electronic search (Figure 1). After screening of the titles, abstracts, and full-text articles, 55 publications were included that reported a digital application in dental education. The manual search retrieved 27 additional publications, resulting in the inclusion of 82 studies (Annex S1 and Annex S2).

**Figure 1.** Systematic search strategy.

The publications were categorized into six areas of digital dental education:


#### *3.1. Web-Based Knowledge Transfer*/*e-Learning*

Fifteen studies reported the use of Web-based learning tools in the dental curriculum, comprising orthodontics [12,13], tooth anatomy [14–16], oral pathogens andimmunology [17], dental radiology [18,19], oral surgery [20] or implant dentistry [21], prosthetic dentistry [22], caries detection [23,24], in growth and development [25], and the general use of Web-based learning tools [26] (Table 1). Three additional studies reported on the use of video illustrations of clinical procedures with behavior management in pediatric dentistry [27], intraoral suturing [28], or tooth preparation [29]. Practicing history-taking and decision-making in periodontology with a Web-based database application, where students used free text communication on the screen to interact with patient data, improved their capability and empathy during the first patient contact [30]. One other study described the introduction of portable digital assistants for undergraduate students in a primary dental care clinic to access a virtual learning environment; these tools proved to be a convenient and versatile method for accessing online education [31]. Mobile devices were found to support learning by offering the opportunity to personalize digital learning materials by making comments, underlining, annotating images, and making drawings [32]. The availability of free 3D viewer software favored the planning of RPD designs on 3D virtual model situations [33]. Online access to digital tools without time restrictions was identified as a major benefit in dental education, and Web-based instructional modules facilitated students' individual learning approach and accommodated varying learning paces. While an initial effort was required to prepare online educational material, faculty time was reduced in the long term.





RCT = Randomized Controlled Trial; CT = Controlled Trial; CS = Cohort Study; CCS = Case-Control-Study; OT = Observational Study.

#### *3.2. Digital Surface Mapping*

Visual inspection of students' work is known to have shortcomings in inter- and intra-examiner reliability, whereas standardized digital surface mapping of abutment tooth preparations facilitates objective evaluation and feedback (Table 2) [34–46]. In the preclinical training of dental students, the use of software that can match the student's scanned preparation with an ideal tooth preparation has been proven to be a helpful tool in the evaluation of preparation form, taper, and substance removal. High intra-rater agreement was also found for the repeated digital grading of wax-ups in the undergraduate curriculum [47], and students' initial self-assessment was overrated compared to the digital grading [48]. Limitations of digital assessments have been found for intracoronal cavity preparations, due to the restricted analysis of cavity depth [49,50]. With specified software skills, successful application was documented for class II mesio-occlusal-distal (MOD) cavity assessments, class III composite preparations, and mesio-occlusal (MO) onlay preparations [51–53]. These studies of digital surface mapping clearly demonstrate the tremendous development of this technology since 2006, which now enables a thorough and consistent analysis of several preparation parameters, with freely available open-source comparison tools.






RCT = Randomized Controlled Trial; CT = Controlled Trial; CS = Cohort Study; CCS = Case-Control-Study; OT = Observational Study; ICC = Inter-Class Correlation; STL = Standard Tessellation Language.

#### *3.3. Dental Simulator Motor Skills Including Intraoral Optical Scanning*

A high level of interest and acceptance was documented among undergraduate students for simulator training in cavity preparations [54–56], or in surgical interventions such as apicoectomies (Table 3) [57]. A trend toward improved technical skills and ergonomics was documented when simulator training with real-time feedback was added to traditional instructions [58–60]. Training with a VR-based simulator improved students' preparation of class I occlusal cavities [61], and of abutments for porcelain-fused-to-metal crowns [62]. In evaluating the manual dexterity of students, professionals, and non-professionals, the simulator scoring algorithm showed a high reliability to differentiate between non-professionals and dental students or dentists [63]. Instruction time from faculty for teaching cavity and crown preparations was significantly reduced when virtual reality computer-assisted simulation systems were used compared to contemporary non-computer-assisted simulation systems [64]. Preparation performance on VR units with continuous evaluations and advice from clinical instructors led to better preparation quality than real-time feedback from the virtual dental unit. Self-paced learning and the immediate software feedback were beneficial with the VR unit, and it was perceived as adjunct, but not replacing faculty instructions [65]. Students requested software improvements with more realistic force feedback during interaction with different tissues in the virtual oral environment including the maxilla, mandible, gum, tongue, cheek, enamel, dentine, pulp, cementum, etc. [66]. Recent advancements of simulators enabled variations in force feedback accounting for varying hardness of the virtual material, cut speed gain, and push force [67].

Improved student performance in crown digitization and framework design was observed when CAD/CAM (Computer-Aided Design/ Computer-aided manufacturing) courses were introduced in dental education [68]. While students enjoyed designing a full crown using CAD as compared to traditional waxing, limits of the technology in representing anatomic contours and excursive occlusion were identified [69]. Viewing their scanned crown preparations magnified on the screen improved students' understanding of the finishing line [70]. The application of IOS in the simulation training showed that even inexperienced dental students were capable of acquiring the skills needed to use digital tools, and students preferred IOS over conventional impressions [71,72]. Furthermore, students' work time was shorter with IOS than with conventional impression [72,73], although more teaching time was required for digital scanning than for conventional impression techniques [74]. Applying digital complete denture treatment (AvaDent; AvaDent Digital Dental Solutions, Scottsdale, AZ, USA) in the student clinics resulted in restorations with superior gradings that were preferred by both students and patients [75]. Using an intraoral camera increased patients' consent for crown treatment, and was positively perceived by students and patients, while faculty members were neutral [76].


#### **Table 3.** Dental simulator motor skills incl. IOS (*n* = 23).




RCT = Randomized Controlled Trial; CT = Controlled Trial; CS = Cohort Study; CCS = Case-Control-Study; OT = Observational Study; DSF = VR group with instructor feedback; DS = VR group without instructor feedback; NDS = Neither VR simulator training nor faculty feedback; VAS = Visual Analog Scale; IDEA = International Dental Education Association.

camera use optional.

#### *3.4. 3D Rapid Prototyping*

Two studies evaluated training models created by 3D rapid prototyping [77,78]. Such methods can supplement teaching on human teeth or even replace it, and educational needs can easily be adapted to students' skills (Table 4).



RCT = Randomized Controlled Trial; CT = Controlled Trial; CS = Cohort Study; CCS = Case-Control-Study; OT = Observational Study.

#### *3.5. Digital Radiography*

Four studies dealt with diagnosing radiographic changes [79–81] or detecting positional errors on panoramic radiographs [82] (Table 5). Senior students showed a poor ability for approximal caries detection on both conventional and digital radiographs when compared to histo-pathologic analysis from sectioned teeth [80]. One study demonstrated that digital learning supported the development of students' diagnostic skills [81]. Another study showed that the accuracy of radiographic caries detection was improved by a computer-assisted learning calibration program, which provided feedback illustrating the actual tooth surface condition [79]. In one study, two digital systems for endodontic tooth length measurements were compared, and students' positive attitudes towards digital radiography were documented [83].


**Table 5.** Group 5: Digital Radiology (*n* = 5).


RCT = Randomized Controlled Trial; CT = Controlled Trial; CS = Cohort Study; CCS = Case-Control-Study; OT = Observational Study; CCD = Charged Couple Device; PSP = Photostimulable Phosphor.

#### *3.6. Surveys Related to the Penetration and Acceptance of Digital Education*

Six surveys evaluated students' perception and acceptance of digital technologies (Table 6) [84–89]. The more recent studies reflected that digital technologies have become established teaching tools, particularly in the field of digital radiography and microscopy, and the use of textbooks decreased; simulation training was preferred [86,87].


#### **Table 6.** Surveys related to digital education (*n* = 10).


RCT = Randomized Controlled Trial; CT = Controlled Trial; CS = Cohort Study; CCS = Case-Control-Study; OT = Observational Study.

Four surveys analyzed the penetration of and attitudes towards digital technologies at dental schools in the UK [90], U.S. [91], North America [2], or among the faculty staff at a dental school in Malaysia [92]. According to the most recent survey, CAD/CAM technologies were taught in most dental schools in North America (93%), while other digital modalities showed less penetration [2].

Despite a high acceptance of digital technologies in dental education by faculty [92] and students [86], it was concluded that e-resources should not replace interactions with faculty; students wanted lectures and clinical procedures recorded [85].

#### **4. Discussion**

The systematic review aimed to investigate current penetration and educational quality enhancements from digitalization in the dental curriculum. Heterogeneous study types addressing various fields of digital applications were found. While a meta-analysis was not feasible, a descriptive approach for identified publications was conducted.

Digitalization in dental education is frequently used to enhance the accessibility and exchange of documents and to facilitate the collaboration and communication among students, teachers, and administrative staff. Digitalization enables cloud-based records, evaluation, and feedback, as well as the provision of e-learning modules [23]. Students today, particularly the Millennials, expect services instantly, expect to be able to download their grades, course schedules, and other information automatically, and to be able to get assistance 24 h a day. In order to satisfy these expectations, it is necessary to promote a change of mindset of the dental faculty and provide instructors with training in e-learning and e-teaching to enable theoretical and practical knowledge transfer [85]. The coronavirus disease (Covid-19) pandemic that started in 2019 caused dental schools around the world to close, and highlighted the need for alternative channels for education (e.g., Web-based learning platforms) [93]. Scheduled webinars can provide a structure for students' theoretical learning. Additional applications of digital features include educational videos illustrating clinical exams or therapeutic steps, interactive systems, adaptive systems that monitor students' ability and adjust teaching accordingly, online collaborative tools, etc. The use of pictograms instead of scripts in educational videos facilitates a language-independent application in several countries.

Especially in the field of motor skills training, digital software tools can be used to evaluate the manual abilities of potential candidates for the dental curriculum, to analyze students' preclinical preparations, to enable self-assessment, and to enhance the quality of education. The objective and exact nature of these digital evaluations helps to improve students' visualization, provides immediate feedback, and enhances instructor evaluation and student self-evaluation and self-correction [43,94]. Students can learn to self-assess their work with self-reflection and faculty guidance in conjunction with a specially designed digital evaluation tool [48]. IOS and digital impression techniques can be included early in the dental curriculum to help familiarize students with ongoing development in the computer-assisted technologies used in oral rehabilitation [3,72].

While undergraduate students today have to be prepared for digital dentistry, they still need to acquire the knowledge of conventional treatment strategies and processes. Growing up in the digital world, they will easily adapt to digital features. Digital dentistry offers several options for an objective standardized evaluation of students' performance, which should be used for quality enhancement. It is currently a "teaching transition time", and new standards have to be defined for dental education in general. Open questions remain, such as: (i) in which phase of the dental curricula should digital technologies be introduced as the routine tool; (ii) which analog techniques can be omitted; and iii) which digital content should be taught in which disciplines?

Several studies indicated that personal instruction and feedback from faculty cannot be replaced by simulator training and feedback [39,65,85]. In this context, faculty should be aware of their responsibility in teaching young dentists, who are treating individuals with individual needs requiring empathy and an informed consent for any treatment decision. Digitalization cannot replace all educational lessons or

courses, and the role-model function of faculty is important when supervising students during patient treatment in the clinical courses.

It should be emphasized that there are still no uniform standards in dental education with regard to the digital tools applied. Such standards are essential to ensure uniformity in teaching, which is particularly important for an international exchange. Society as well as dentistry is currently undergoing a digital transformation. It is necessary to clarify learning contents, to what extent conventional workflows should still be taught, and what can be done digitally. While digital tools and applications in knowledge transfer are a general challenge for undergraduate education in all disciplines, the field of dentistry with its high degree of practical training units is specifically demanding. Just because training units are designed digitally does not mean that students learn on their own. Continuous training with supervision and feed-back is still the key to good dental education. In this context, digitization is certainly a great opportunity to convey the learning content with more joy and newly awakened enthusiasm.

Following the rule, "you can only teach what you are able to perform yourself", a highly motivated faculty is needed that is willing to embrace the latest digital technologies. Besides personal motivation, the financial aspect of implementing the various digital tools and applications has to be managed at dental universities. Collaborations with industry would be helpful here. This is a classic "win–win situation"—the dental school would be equipped with the latest products and updates, and the industry would get access to the youngest target group of potential customers. In the event of such collaborations, it is vital that universities maintain their objectivity by offering a variety of products from diverse companies; otherwise, there is a risk of unduly influencing dental students and biasing them towards one particular technological option. The rapid pace of change in dental technology must also be considered. Dental technology companies are constantly introducing new products and workflows. While this provides exciting opportunities for dental research, to test and analyze those new developments, it complicates the implementation of digital workflows in dental education programs. New job descriptions are also necessary at dental schools in order to maintain the technical infrastructures required for these new technologies and to guarantee a smooth operation in clinical practice. In future, the best dental schools will be ranked according to their digital infrastructure combined with the level of innovation of the teaching faculty.

#### **5. Conclusions**

Digital tools and applications are now widespread in routine dental care. Therefore, this trend towards digitization and ongoing developments must be considered in dental curricula in order to prepare future dentists for their daily work-life. There is a need to establish generally accepted digital standards of education—at least among the different dental universities within individual countries. Digitalization offers the potential to revolutionize the entire field of dental education. More interactive and intuitive e-learning possibilities will arise that motivate students and provide a stimulating, enjoyable, and meaningful educational experience with convenient access 24 h a day.

At present, digital dental education encompasses several areas of teaching interests, including Web-based knowledge transfer and specific technologies such as digital surface mapping, dental simulator motor skills including IOS, and digital radiography. Furthermore, it is assumed that AR/VR-technology will play a dominant role in the future development of dental education.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/1660-4601/17/9/3269/s1, Annex S1 and Annex S2.

**Author Contributions:** Conceptualization, Methodology, and Writing—Original Draft Preparation, N.U.Z. and T.J.; Writing—Review and Editing, N.U.Z., T.J., L.M., and H.O.; Supervision, N.U.Z. and T.J.; Project Administration, T.J. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflicts of interest.

#### **References**


© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

International Journal of *Environmental Research and Public Health*
