This prospective cohort study investigated the potential of digital assessment using intraoral scanning (IOS) combined with software-analysis (prepCheck) to evaluate the outcome of repetitive tooth preparation and its influence on the acquisition of motor skills in dental students. Twenty-six students completed 177 full-crown preparations of the same tooth in six practice sessions followed by a final exam. Preparations were assessed digitally using prepCheck and conventionally by calibrated faculty instructors. In addition, students assessed their own performance and this was compared to the instructors’ assessments. Conventional assessment showed that students preparations improved over time, with 43.5% of students receiving score 2 (highest grade) at the fifth practice session. With the prepCheck assessment, statistically significant improvements indicated by an enlarged area within the tolerance range set at 0.2mm was found between the first and the second practice session (7.5% improvement; 95% CI: 2.2%, 12.7%, p=0.006), and between the first run and the final exam preparation (6.7%; 95% CI: 1.7%, 12.5%, p=0.011). Agreement between instructor/student assessment was best immediately after students received visual feedback using prepCheck (76% agreement; Spearman’s rho 0.78). These data indicate that IOS technology was useful for student’s self-evaluation by visual feedback.