Cláudia Barbosa, Tiago Reis, José B. Reis, Margarida Franco, Catarina Batista, Rui B. Ruben, Benjamín Martín-Biedma, José Martín-Cruces
This study aimed to evaluate the aging effect (6 and 12 months), relative to baseline (0 months), on the dimensional accuracy, morphological stability, and shaping behavior of PolyJet™ 3D-printed teeth (3DPT) produced in two printing orientations (X and Y axes). Specimens (XA0, XA6, XA12, YA0, YA6, YA12) were analyzed using microcomputed tomography before and after root canal preparation with the ProTaper Gold® system. Preoperative analysis included canal volume, centroid, total tooth volume, and total tooth area. Aging-related changes were observed, with significant differences between XA0 and XA12 (p < 0.05), whereas no differences were detected among Y-axis groups (p > 0.05). These findings indicate that X-axis specimens are not comparable over time, while Y-axis specimens maintain baseline consistency. Postoperative evaluation revealed significant differences across aging conditions for most endodontic preparation parameters. Within the limitations of this study, aging had a limited effect on dimensional accuracy but influenced the shaping behavior of 3DPT. Based on these findings, future studies using PolyJet™ 3DPT should report the printing batch and the storage time between fabrication and experimental use, as these factors may influence the comparability and reliability of the results.