Multi-resin 3D printing of radiopaque customized artificial tooth for revolutionizing preclinical training on root canal treatment

Objectives: This study aims to 3D print customized dental models using a multi-material 3D printer that can mimic natural human teeth. The model consists of a detailed tooth with adequate radiopacity and pulp cavity which will be used for preclinical endodontic training. Methods: A radiopaque resin with varying barium sulfate (BaSO₄) ratios was synthesized to optimize printability and radiopacity. The artificial tooth with a pulp cavity was created from micro-computed tomography (micro-CT) data and printed using a multi-resin 3D printer, employing clinical A2 resin (AA-Temp) for the tooth body and soft red resin for the pulp. Periapical radiography evaluated the radiopacity, and the effect of BaSO₄ on resin viscosity and hardness was measured. Results: Experimental results show that adding a 10% weight ratio of BaSO₄ in A2 resin can obtain the highest radiopacity of the printed tooth. Furthermore, the study successfully fabricated incisor and molar tooth models for preclinical endodontic training which closely matched the natural human tooth in terms of appearance, size, and shape. Originality and significance: The multi-material 3D printing technology that is capable of fabricating hard and soft parts of the tooth is self-developed. Furthermore, two training models were successfully framed for students to get hands-on experience in root canal treatment of incisor and molar teeth. The enhanced confidence gained by training on the 3D-printed tooth that closely matches the characteristics of a natural human tooth would increase the clinical success rate.