Objective: This study aims to evaluate the effect of the ultrasonic cleaning method on the flexural strength of resin-based composites used in 3D printing production.

Materials and Methods: 55 samples were produced according to the appropriate procedures on 3D printers using three different 3D printer resins (CDS Custom Composite Resin, Saremco Crowntec, Senertek P Crown V3). Post-curing procedures were carried out in accordance with the manufacturer’s recommendations. ANOVA test and post Hoc Tukey HSD tests were used to compare flexural strength among the different crown resins. Independent-t test was used to compare the flexural strength between the groups of ultrasonic and non-ultrasonic groups. Statistical significance was accepted as p<0.05.

Results: The flexural strength value of Saremco Crowntec composite resin was 93.58±5.43 MPa, while the flexural strength of CDS Custom composite resin was 74.69±6.90 MPa and the difference between them was found to be highly significant (p<0.001). The flexural strength value of Senertek P Crown V3 composite resin was 87.26±15.22 MPa and the difference with CDS Custom composite resin was found to be highly significant (p= 0.002). The flexural strength value of Senertec P Crown V3 resin in the non-ultrasonic cleaning procedure was 87.26±15.22 MPa. The flexural strength value of Senertec P Crown V3 resin in the ultrasonic cleaning procedure was found to be 73.56±4.61 MPa. According to the results of the independent samples t-test, only the comparison of ultrasonic and non-ultrasonic cleaning values of Senertek P Crown V3 composite resin was statistically significant (p= 0.028).

Conclussion: Ultrasonic cleaning method reduced the flexural strength value of Senertek P Crown V3 resin.