Influence of Polymerization Postprocessing Procedures on the Accuracy of Additively Manufactured Dental Model Material.

Purpose: To measure the influence of postpolymerization condition (dry and water-submerged) and time (2, 10, 20, and 40 minutes) on the accuracy of additively manufactured model material.

Materials and methods: A bar standard tessellation language (STL) file was used to manufacture all the resin specimens using a 3D printer. Two groups (n = 80 each) were created based on postpolymerization condition: dry (D group) and water-submerged (W group). Each group was then divided into four subgroups (D1 to D4 and W1 to W4; n = 20 each), which were each assigned a postpolymerizing time (2, 10, 20, and 40 minutes). The specimens' dimensions were measured using a low-force digital caliper. The volume was calculated as follows: V = l × w × h. Shapiro-Wilk test revealed that the data were not normally distributed. Data were analyzed using Kruskal-Wallis and pairwise Mann-Whitney U tests (α = .05).

Results: Significant differences in length, width, height, and volume were found among the subgroups (P < .0018). In all groups, the width dimension (x-axis) presented less accuracy compared to height (z-axis) and length (y-axis) (P < .0018). The D2 and D4 subgroups obtained the closest dimensions to the virtual design, and there were no significant differences between these subgroups (P < .0018). The dry condition showed higher manufacturing accuracy than the water-submerged condition. In the water-submerged subgroups, the highest accuracy was obtained in the W2 and W4 subgroups (P < .0018).

Conclusions: Postpolymerization condition and time influenced the accuracy of the material tested. The dry postpolymerization condition with times of 10 and 40 minutes obtained the highest accuracy.