Ceramics-Silikáty 66, (1) 66 - 77 (2022)

This study aims to compare the biaxial flexural strength of four bonded and unbonded monolithic CAD/CAM restorative materials. Twenty disk-shaped specimens (10 mm in diameter and 2 mm in thickness) were fabricated from four CAD/CAM materials (N = 80): IPS e.max CAD, VITA Suprinity, VITA Enamic, and DD cubeX². The bonded and unbonded disks were subjected to biaxial flexural stress using a universal testing machine, followed by fractographic and scanning electron microscopic analysis of the fractured samples. In the unbonded group, a significant difference in the biaxial flexural strength was observed (P ˂ .0001): DD cubeX² (566.3 MPa) ˃ IPS e.max CAD (410.5 MPa) ˃ VITA Suprinity (330.7 MPa) ˃ VITA Enamic (247.3 MPa). In the bonded group, a statistically significant difference was noted: DD cubeX² (676.5 MPa), VITA Enamic (619.3 MPa), IPS e.max CAD (605 MPa), and VITA Suprinity (544.2 MPa) (P = .009). When cemented, all the CAD/CAM materials showed an increase in the biaxial flexural strength. The bonded VITA Enamic exhibited values comparable to DD cubeX² and significantly higher than IPS e.max CAD and VITA Suprinity.