Introduction of a new teaching concept for crown preparation with 3D printed teeth.

INTRODUCTION For both students and teachers, it is challenging to learn and teach a correct crown preparation. The purpose of this study was the design, feasibility and evaluation of a 3D printed tooth model with internal preparation for dental education in crown preparation and to analyze the quality of the prepared printed teeth in comparison to prepared standard model teeth. MATERIALS AND METHODS A printable tooth was designed and printed by a stereolithographic printer. 38 fourth-year dental students in the first clinical course in prosthodontics were trained in a voluntary course using printed teeth. Different aspects of the printed tooth were evaluated by a questionnaire using German school grades (1 best to 6 worst). The quality of the preparation with the printed teeth and standard training teeth was also rated in an evaluation form done by an expert group consisting of five experienced dentists. RESULTS The workflow was feasible and cost-effective for the production of the teeth. The overall rating of the printed tooth was Ø 2.0 ± 0.34 in the questionnaire completed by the students. The students rated the printed tooth model (Ø 2.1 ± 0.85) as significantly better than the standard model tooth (Ø 3.3 ± 0.77; p=0.000). The students reported great benefits in the use of this model tooth e.g. valuable replacement of a standard model and real teeth, direct control of material loss. The quality of the preparation was evaluated by the expert group as significantly better with an overall mean grade of Ø 2.6 ± 0.37 for the printed teeth compared to Ø 2.9 ± 0.42 for the standard model teeth (p = 0.000). CONCLUSIONS The feasibility of this teaching concept was confirmed. The students favored to work on the innovative 3D-teeth with internal preparation, emphasizing the usefulness of this technique in dental education. The expert group confirmed also the significant training effect of this tooth model in contrast to a standard model tooth.