LAUSR

PURPOSE The aim of this study was to assess the validity of in silico models of three-point bending tests to reflect in vitro physical properties obtained from three commercially available computer-aided design/computer-aided manufacturing (CAD/CAM) resin composite blocks and demonstrate notchless triangular prism analysis with those properties. MATERIAL AND METHODS Three types of commercially available CAD/CAM resin composite blocks were used: Cerasmart 300 (CS300; GC, Tokyo, Japan), Katana Avencia P Block (AP; Kuraray Noritake Dental, Tokyo, Japan), and KZR CAD HR3 Gamma Theta (GT; Yamakin, Osaka, Japan). In vitro/in silico three-point bending tests were conducted to obtain elastic modulus and fracture strain for non-linear dynamic finite element analysis (n = 10/each). Fractured surfaces of specimens after in vitro NTP tests were observed, and the fracture toughness of each CAD/CAM resin composite was obtained by in silico NTP analysis. RESULTS Both in vitro and in silico load-displacement curves obtained from three-point bending tests were significantly correlated (p < 0.05). The elastic moduli of CS300, AP, and GT were 8.0 GPa, 10.0 GPa, and 9.0 GPa, respectively. The fracture toughness values obtained from in silico NTP analysis of CS300, AP, and GT were 5.057 MPa m1/2, 4.193 MPa m1/2, and 4.880 MPa m1/2, respectively. There was no significant difference in the length of the stable region among the three CAD/CAM resin composites (p = 0.09). CONCLUSIONS The in silico approach established in this study showed acceptable reflection of in vitro physical properties and will be useful for assessing fracture toughness related to the longevity of CAD/CAM resin composites without wastage of materials.