Comparison of Flexural Strength According to Post-Curing Treatment Time of Cast Resin Printed by 3D Printing Method

Objective: This study compared and analyzed the effect of post-curing treatment time of cast resin manufactured using DLP type 3D printing technology on the flexural strength. Methods:The experiment was performed by outputting a specimen designed according to ISO 20795-1:2013 standard using a DentaCAST resin (Asiga, Australia), and then dividing the post-curing treatment time into three groups (A, B, C) by setting the time to 5, 10, and 15 minutes.The flexural strength of each group was measured using a universal tester, and the data were analyzed with an SPSS statistical program and then the significance analysis was performed by one-way ANOVA test.Multiple comparisons after analysis were performed by Tukey HSD Test (p<0.001).Results: As a result of the experiment, the flexural strength significantly increased as the curing time increased, and the average flexural strength of the 5-minute cured experimental group (A) was 88.51 MPa, the 10-minute cured experimental group (B) was 105.32 MPa, and the 15-minute cured experimental group (C) was 121.89 MPa.This is judged to be the result of improving the mechanical characteristics of the output by increasing the density of the polymer network due to the additional polymerization reaction during the photopolymerization process. Conclusion:This study confirmed that the curing process after output is an important factor in determining the mechanical properties of 3D printing outputs.In future studies, follow-up studies on various 3D printing methods and materials are needed.