A Novel Electro-Typodont for Measuring the Efficacy of 3D-Printed Orthodontic Aligners

Objectives: To introduce a novel method—an electric typodont model—to evaluate the efficacy of 3D-printed orthodontic aligners in correcting rotations of the upper right central incisor (Tooth 11). Materials and Methods: An electric typodont fitted with heat-activated wax blocks was employed to simulate four severities of rotation of Tooth 11: 22°, 32°, 42°, and 52°. Each setup was scanned and treatment planned in Maestro 3D software to produce four sequential aligners per angulation. In total, 240 aligners were 3D-printed in three thicknesses (0.50 mm, 0.75 mm, and 1.00 mm). After seating each aligner on the typodont, a 10-minute heat cycle was applied, immediately followed by a 10-minute cooling cycle. Afterward, the degree of derotation was measured with a protractor against a fixed baseline. Tooth 11 was then reset using rigid guiding stents, and the procedure was repeated five times per subgroup to ensure reliability. Results: The electric typodont reliably simulated incisor derotation. By the fourth aligner, all three thickness groups reduced the initial rotations to approximately 4–5°, though they differed in early-stage performance. The 0.50 mm and 1.00 mm aligners produced larger initial corrections, particularly between Aligners 1 and 2, whereas the 0.75 mm aligners demonstrated a more uniform, gradual derotation. By the final stage, all groups converged on the same minimal residual rotation. Conclusions: The electric typodont is a reliable pre-clinical model for simulating aligner-driven tooth movement. Moreover, sequential 3D-printed aligners succeeded effectively in derotation of anterior incisors at different severities, without attachments.