Influence of build orientation and storage duration on the accuracy of fused deposition modeling-fabricated polyetheretherketone removable partial denture frameworks

This study investigated the effects of build orientation and water-storage duration on the dimensional accuracy of fused deposition modeling (FDM)-fabricated polyetheretherketone (PEEK) removable partial denture (RPD) frameworks. The specimen geometry was designed using computer-aided design (CAD) software to simulate a maxillary RPD framework and printed in three build orientations (0°, 45°, 90°; n=6). After annealing, specimens were immersed in 37°C water and scanned after 24 h, 1 week, 1 month, 2 months, 4 months, and 6 months. Trueness was calculated by superimposing scanned stereolithography (STL) data onto the CAD reference, and precision was assessed within each group. Storage duration significantly influenced trueness and precision, with clinically acceptable accuracy achieved after 24 h and maintained stable for more than 2 months under simulated intraoral moisture and temperature. The 90° orientation demonstrated the most consistent reproducibility.