BALL-ON-THREE-BALLS BIAXIAL FLEXURAL STRENGTH OF BONDED AND UNBONDED CAD/CAM MATERIALS

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 cubeX 2 . 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 cubeX 2 (676.5 MPa), VITA Enamic (619.3 MPa), IPS e.max CAD (605 MPa), and VITA Suprinity (544.2 MPa) (P = 0.009). 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.