Accuracy of tooth positioning in 3D-printing aided manufactured complete dentures: An in vitro study

In this study, we propose a 3D printing-aided method for manufacturing complete dentures and evaluate its accuracy of artificial tooth positioning. Complete dentures were designed and 3D printed and put on a plaster cast; and pack and press technique was used to fabricate the final denture during which artificial teeth were inserted in the teeth holes formed by the printed denture. In this study, fused deposition moulding (FDM) and stereolithography (SLA) techniques were used to fabricate complete dentures (10 pairs of maxillary and mandibular dentures each). After 3D scanning the final dentures, 3D comparison between the scanned teeth on the denture and its computer-aided design (CAD) data was made and single-tooth deflection angles were measured to evaluate the tooth position. Values were compared using independent-sample t-tests or the Mann–Whitney U test. In the result of 3D comparison, the root mean square values of artificial teeth were 0.107 ± 0.018 mm (SLA group) and 0.136 ± 0.023 mm (FDM group; P < 0.05). In the result of single-tooth deflection angles, the mandibular anterior teeth demonstrated the maximum deflection angle, followed by the molars, premolars, and maxillary anterior teeth. It is feasible to fabricate complete dentures using 3D-printed complete dentures as prototypes and combine conventional methods. The accuracy of the final denture fabricated using SLA printing was better than that of dentures produced using the FDM method. The 3D printing-aided manufacturing for complete dentures refers to using the 3D-printed dentures as a prototype along with the traditional process to fabricate final dentures and is an effective alternative when the dentures cannot be directly processed using computer-aided manufacturing (CAM).