PURPOSE: To investigate the effect of digital scanning combined with reverse engineering technology in the demonstration of full-crown tooth preparation. MATERIALS AND METHODS: A total of 31 students were randomly divided into two groups. The students in the control group conducted traditional demonstration using eye-measurement methods. The students in the experimental group carried out improved demonstration using digital intraoral scans with 3D-measurement data. The students in both groups were provided with two resin teeth to conduct full-crown tooth preparation on head model dental simulators. The teeth prepared before and after demonstration were scored according to Chinese Stomatological Association Group Standards with a total score of 100 points. Analysis of covariance (ANCOVA) was performed to comparatively analyze the scores related to the tooth surfaces and the convergence angle between the two groups. RESULTS: Analysis of two prepared teeth (a maxillary right central incisor and first molar) in two groups showed that there was a statistically significant difference in the mean score between the control group and experimental group (central incisor, P = .0039
first molar, P = .0120). The demonstration of the first molar showed that there were statistically significant differences in the scores related to the buccolingual surface (P = .0205) and proximal surface (P = .0023) between the control group and experimental group. There was a statistically significant difference in the score related to the convergence angle of the buccolingual surface between the control group and experimental group (P = .0265). CONCLUSIONS: The digital method can effectively improve the quality of tooth preparations and has a pedagogic advantage for posterior teeth, which present greater operational challenges.