Fused filament fabrication of radiopaque barium sulfate-reinforced polyetheretherketone composites for thin-walled patient-specific orbital reconstruction

Abstract

Fused filament fabrication (FFF) of high-performance thermoplastic composites for medical applications remains challenging due to the need to meet geometric precision, mechanical, and functional requirements. This study presents the first systematic evaluation of FFF radiopaque barium sulfate-reinforced polyetheretherketone (BaSO₄-PEEK) for patient-specific orbital reconstruction, addressing dimensional accuracy, mechanical properties, and surgical precision in thin-walled implants. Six implants per material group (unfilled PEEK and 20 wt% BaSO₄-PEEK) with 0.8 mm nominal wall thickness and complex orbital geometries were fabricated and evaluated. Optical scanning showed submillimeter-level dimensional accuracy, with root-mean-square error (RMSE) of 0.31 ± 0.09 mm for unfilled PEEK and 0.33 ± 0.08 mm for BaSO₄-PEEK, confirming that incorporating an organic filler does not compromise manufacturability. Biomechanical testing revealed that FFF BaSO₄-PEEK implants maintained adequate puncture strength (17.58 ± 0.46 N/mm²), comparable to titanium mesh. Radiographically, BaSO₄-PEEK implants provided a 38% higher contrast-to-noise ratio than titanium and eliminated metal artefacts that obscured adjacent soft tissues. Cadaveric implantation demonstrated reconstruction accuracy (RMSE) of 0.61 ± 0.15 mm, which was better than that of manually contoured titanium mesh. These results establish FFF as a viable manufacturing method for complex, thin-walled, radiopaque PEEK composite orbital implants that provide sufficient dimensional control and mechanical performance in clinical scenarios.