Impact of 3D resin and base designs on the accuracy of additively manufactured casts using a stereolithography technology.

STATEMENT OF PROBLEM: Three-dimensional (3D) printed casts can be fabricated using a wide range of 3D polymer resins and designed with varying casts base configurations. Nevertheless, the influence of different base designs, in conjunction with various 3D printing resins, on the final dimensional accuracy of casts manufactured through SLA-LCD 3D printing technology remains unclear. PURPOSE: This study assessed the impact of 3D printing resins and base designs on the dimensional accuracy of diagnostic casts fabricated using a SLA-LCD vat-polymerization 3D printer. Two resins (NextDent Model 2.0 and Aqua Gray 4K) and 5 different base configurations were evaluated for their effect on trueness and precision. MATERIAL AND METHODS: A digital maxillary cast was modified into three base designs: solid (Group S), honeycomb (Group HC), and hollow (Group H). Honeycomb and hollow designs had subgroups with 1-mm (HC1, H1) and 2-mm (HC2, H2) wall thicknesses, resulting in 50 specimens (n=10 per subgroup). Eleven embedded precision cubes were used for accuracy assessment. A Sonic Mini 4K vat-polymerization printer was used for cast printing, and dimensional deviations were captured using a coordinate measuring device. Trueness was defined by the average dimensional discrepancy, and precision was indicated by the standard deviation. Statistical analysis included Kruskal-Wallis and Mann-Whitney U tests (alpha=.05). RESULTS: NextDent resin showed trueness falling between 44.8 5 microm and 64.5 microm and precision values varying between 33.5 5 microm and 48.9 microm, while Aqua Gray 4K resin ranged from 24.1 5 microm to 81.1 microm for trueness and 19.8 5 microm to 65.9 microm for precision. Significant differences (P<.001) were observed in all axes (x-, y-, z-axes) and 3D deviations, influenced by resin and base design. CONCLUSIONS: Resin type and base design significantly affect the dimensional accuracy of 3D printed casts. Aqua Gray 4K with a 2-mm hollow base provided the highest accuracy, particularly when matched with the printer manufacturer. All casts met clinical standards.