Effect of Three-Dimensional-Printed Teeth With Isthmus on Undergraduates' Pre-clinical Root Canal Preparation and Obturation Trainings.

Objectives: To evaluate the effect of three-dimensional (3D)-printed teeth with isthmus on the pre-clinical root canal preparation and obturation training of undergraduates.

Methods: 3D-printed teeth with isthmus were made from the micro-computed tomography data of a lower first molar from a Chinese permanent teeth database. One hundred and four undergraduates performed root canal preparation and obturation in plastic and 3D-printed teeth within 20 min each using a manikin system. Then, students completed questionnaires, and two independent teachers scored the obturated teeth using X-rays.

Results: The plastic teeth scored higher than 3D-printed teeth in total and the filling density scores (p < 0.05). All students obturated the isthmus. In questionnaire surveys, during the preparation training, students found plastic teeth better in identifying pulp chamber morphology and root canal orifices (49.41%) and provided a better feeling of drill (56.47%). 54.12% of the students indicated that 3D-printed teeth provided a better feeling of the pathway and internal conditions of root canals when using K-files. During the obturation training, over 50% of students felt 3D-printed teeth had advantages in providing gutta-percha point grip senses, manipulation tactile sense, and procedural understanding. Over 98% of students agreed that using 3D-printed teeth with isthmus could enhance learning interest, anatomy understanding, operation skills, and confidence.

Conclusions: 3D-printed teeth had evident advantages over traditional plastic teeth in root canal preparation and obturation training. Undergraduates adapted better to the root canal preparation and obturation practices using the 3D-printed teeth. With improved materials and methods, various root canal systems could possibly be printed for diverse purposes.