Comparison of Mechanical Properties of Patient-Specific Direct 3D-Printed Aortic Valve for Simulation Trainings: A Comparative Study

This study evaluated how postprocessing and pigmentation influence the mechanical realism of directly 3D-printed, patient-specific aortic models (including the aortic valve) intended for surgical simulation training. Using a digital light processing (DLP) workflow to fabricate soft-material aortic constructs, the authors prepared test coupons under different postcuring durations (5, 10, 15, and 20 minutes) and compared uncolored samples to pigmented (pink, orange) samples (10-minute postcure). To mimic common simulation-use damage modes, specimens were tested in three conditions per group: intact/unmodified, with a small incision (cutting simulation), and with two suture holes (suturing simulation). Mechanical response was quantified via stress–strain behavior and derived metrics including stiffness/elastic modulus, ultimate tensile strength, strain at failure, flexibility near suture holes, and toughness (area under the curve), with special emphasis on the two-hole condition as most relevant to suturing practice. Results indicated that uncolored samples postcured for 15 minutes provided the most favorable balance between flexibility, stiffness, and toughness for simulation training, while colored samples tended to show increased stiffness and reduced tensile strength and toughness versus uncolored counterparts. The authors also note practical testing limitations (e.g., grip slippage and incision-size variability) that can under-report absolute maxima, underscoring the importance of standardized handling and grip design for soft printed materials used in simulation models.