Effect of a digital assessment system for the preclinical tooth preparation of metal-ceramic crowns: A pilot study

Tooth preparation is a fundamental aspect of prosthodontics and serves as a focal point in preclinical courses. Conventional pedagogy relies heavily on the expertise of instructors, whereas digital technology has the potential to offer instantaneous feedback. The efficacy of a digital assessment system in comparison with traditional teaching methods remains uncertain.

The purpose of this study was to compare the training effects of traditional assessment and digital evaluation on tooth preparations for the metal-ceramic crowns performed by preclinical students on the convergence angle and tooth reduction.

A total of 40 predoctoral students were randomly divided into the digital group and the traditional group to complete tooth preparation for a metal-ceramic crown on a left mandibular first molar. Students in the traditional group were taught by an experienced instructor, while the digital group students were trained by an objective digital assessment system without instructor guidance. Each student completed the tooth preparation in 20 min, received feedback according to the respective training methods, and later prepared another tooth. In this way, all students completed 4 tooth preparations in 2 weeks. All preparations were evaluated by an optical scanner. Parameters for comparing the digital group with the traditional group were the convergence angle and reduction at different stages. Questionnaires on the digital training system were answered by the students of the digital group. The t tests or Wilcoxon signed rank tests and chi-squared tests were used to analyze the differences between the 2 groups (α=.01).

A decreasing trend in convergence angle was seen in both groups, but the 2 groups were statistically similar (P>.01). After training, a decreasing trend was seen in under-reduction and overreduction on 5 surfaces in the digital group. Conversely, in the traditional group, a noteworthy increase was seen in under-reduction on the distal surface (P=.002). Nevertheless, no significant difference was found between the 2 groups (P>.01). According to the results of the questionnaire, over 80% of the students had a positive attitude toward the digital assessment system, and more than 80% of the students expressed their interest in the digital assessment system for tooth preparation training.

Traditional teaching and digital feedback provided similar training effects to improve the quality of tooth preparations for preclinical dental students.