Trapped powder removal from complex lattice structures with small macro pore sizes and dental implant application

Additive manufacturing (AM) enables the production of complex geometries, which is particularly beneficial for the fabrication of patient-specific implants. However, powder bed fusion processes pose challenges in removing trapped powder from internal structures. Within this study, powder removal from complex parts using ultrasonic (US) cleaning as well as vibration is investigated. First, open cubic gyroid-TPMS lattice structures with macro pores sizing 300, 450, and 600 μm were fabricated and analyzed. Results indicate that mechanical vibration enhances powder removal, particularly for the smallest macro pore size (300 μm), compared to ultrasonic cleaning alone. Second, a dental implant prototype with a closed outer wall and various internal lattice structures was evaluated. Findings suggest that additional design modifications are necessary to facilitate powder removal, especially for lattice macro pores of approximate 280 μm. However, such modifications to the lattice structures may affect the mechanical integrity of the implant. To assess this, numerical simulations were conducted to investigate whether different lattice configurations lead to earlier or even sudden failure under physiological loading conditions.