Evaluation of Internal Fit of Three-Dimensional Provisional Crowns Printed with Different Orientations and Different Post Curing Time Protocols: An in-Vitro Study

The effect of 3D printing parameters including different Orientations and post curing time protocols on the internal fit of 3D printed provisional crowns is not clear.Aim: This current study is to investigate the effect of three different printing orientations and two different post curing time protocols on the internal fit of provisionalprinted crowns. Methods: A ready-made model of an upper first premolar tooth wasscanned. 30 dies were printed using. One of the printed dies was scanned. The designof crown was made. 30 crowns were printed. 18 Provisional crowns were divided into3 groups (n= 6) according to the printing orientation used: group A (0˚), group B (90˚)and group C (30˚). 12 crowns were divided into 2 groups(n=6) according to the postcuring time protocol used: group F (20 min), group G (40 min). Internal fit was measured using stereomicroscope. The effect of different printing orientations and post curing time protocols was statistically analyzed by using One-way ANOVA and independent T-test using IBM SPSS version 26.0. Results: There was a statistically significantdifference in mean internal gap among the three groups (p≤0.05). The highest meaninternal gap was reported by Group A. The lowest mean internal gap was reported bygroup C. There was no statically significant difference between group F and group G.Conclusion: Changing Printing orientations had an impact on internal fit of provisionalrestoration but changing post curing time protocols (20 min or 40 min) had no effect.