Web-Based Augmented Reality vs. Interactive Presentation for Learning Caries Detection: A Randomized Study on Student Motivation

<b>Background/Objectives</b>: Augmented Reality (AR) is promising in dental education, yet its impact on <i>caries detection</i> training remains underexplored. This study aimed to compare the effect of a web-based AR (WebAR) learning object with a content- and interface-matched interactive 2D presentation on undergraduate students' motivation to learn caries detection. <b>Methods</b>: Two learning objects were expressly designed using a real patient's dental records: a WebAR image-tracking experience (built with Zapworks Studio^®) and a 2D interactive presentation (built with Genially^®). The WebAR object showed the patient's 3D dental arches with tooth-level hotspots linking clinical and radiographic media. The 2D comparator mirrored the same assets and navigation, restricting visualization to 2D. Third-year dental students were randomly assigned to either the AR or Genially^® (G) group. After completing ICDAS-based caries identification, participants completed the 12-item Reduced Instructional Materials Motivation Survey (RIMMS) and provided open-ended feedback. Group differences were tested with the Mann-Whitney U test (<i>p</i> < 0.05). <b>Results</b>: Eighty-five students completed the study (AR n = 46; G n = 39). The AR group achieved a higher total RIMMS score (4.14 vs. 3.53 on a 5-point scale; <i>p</i> < 0.001), with significantly higher means in Attention, Confidence, Satisfaction, and Relevance (<i>p</i> < 0.05). Open-ended comments were more positive with AR (75.8% vs. 31.0%), while graphics-related complaints were more frequent with the Genially^® resource (34.5% vs. 75.0%). <b>Conclusions</b>: WebAR achieved higher RIMMS motivation scores than a content-matched interactive presentation. Adding 3D spatial interaction to otherwise equivalent materials can enhance learners' motivation for caries detection training, while remaining low-cost and scalable.