講演情報
[IO-3]In silico analysis of resin-bonded fixed dental prostheses fabricated by strength-gradient multilayered zirconia
*Okkar Kyaw1, Masanao Inokoshi2,3, Satoshi Yamaguchi4, Manabu Kanazawa1,5 (1. Department of Gerodontology and Oral Rehabilitation, Graduate school of medical and dental sciences, Institute of Science Tokyo, 2. Department of Oral Devices and Materials, Graduate school of medical and dental sciences, Institute of Science Tokyo, 3. Oral Science Center, Institute of Science Tokyo, , 4. Department of Dental Biomaterials, Graduate School of Dentistry, Osaka University, 5. Clinic of General, Special Care and Geriatric Dentistry, Center for Dental Medicine, University of Zurich)
[Objective]
In silico approach is useful for determining the fracture behavior of dental prostheses. This study aimed to evaluate the fracture resistance of single-cantilevered resin-bonded fixed dental prostheses (RBFDPs) made of strength-gradient multilayered zirconia.
[Method]
Load-displacement curves from previously published four-point flexural strength tests were used to determine the input material properties for in silico RBFDP analyses. 1) The in vitro measurements included four-point flexural strength (n = 30) and density measurement (n = 3) of each layer of strength-gradient multilayered zirconia (KATANA Zirconia YML, Kuraray Noritake Dental). Density and fracture strain were used as input material properties in in silico four-point flexural strength analyses. Then, iterative adjustments of elastic modulus were performed until the in silico load-displacement curve merged with the in vitro load-displacement curve.The single-cantilevered RBFDPs computer-aided design (CAD) models with four tooth preparation designs: a) no preparation (NP); b) 0.2 mm palatal preparation (P); c) 0.2 mm palatal and dimple preparation (PD); and d) 0.2 mm palatal and dimple preparation with a proximal box preparation (PDP), were created from reverse engineering of the scanned central and lateral incisors in CAD software (Fusion 360®, version 3.4.35, Autodesk Inc.). The CAD models were then imported into a pre- and post-processor (LS-PrePost, 4.9, ANSYS) to create in silico RBFDP models. A non-linear explicit dynamic finite element analysis was conducted to simulate the load-to-fracture test of single-cantilevered RBFDPs.
[Results and Discussion]
KATANA Zirconia YML consists of enamel, body 1, body 2, and body 3 layers with densities of 6.04, 6.05, 6.06, and 6.07 g/cm³, respectively, and fracture strains of 0.0055, 0.0081, 0.0086, and 0.0082. Their respective elastic moduli were 101.85, 105.49, 104.75, and 103.00 GPa. The PDP model demonstrated the strongest fracture resistance, followed by NP, P, and PD, with a fracture load of 758.62, 742.94, 695.61, and 689.16 N, respectively. In summary, the connector thickness and the loading point are important parameters to consider when designing single-cantilevered RBFDPs.
[Reference]
1) Inokoshi M, Liu H, Yoshihara K, et al. Layer characteristics in strength-gradient multilayered yttria-stabilized zirconia. Dent Mater 2023; 39(4): 430-41.
In silico approach is useful for determining the fracture behavior of dental prostheses. This study aimed to evaluate the fracture resistance of single-cantilevered resin-bonded fixed dental prostheses (RBFDPs) made of strength-gradient multilayered zirconia.
[Method]
Load-displacement curves from previously published four-point flexural strength tests were used to determine the input material properties for in silico RBFDP analyses. 1) The in vitro measurements included four-point flexural strength (n = 30) and density measurement (n = 3) of each layer of strength-gradient multilayered zirconia (KATANA Zirconia YML, Kuraray Noritake Dental). Density and fracture strain were used as input material properties in in silico four-point flexural strength analyses. Then, iterative adjustments of elastic modulus were performed until the in silico load-displacement curve merged with the in vitro load-displacement curve.The single-cantilevered RBFDPs computer-aided design (CAD) models with four tooth preparation designs: a) no preparation (NP); b) 0.2 mm palatal preparation (P); c) 0.2 mm palatal and dimple preparation (PD); and d) 0.2 mm palatal and dimple preparation with a proximal box preparation (PDP), were created from reverse engineering of the scanned central and lateral incisors in CAD software (Fusion 360®, version 3.4.35, Autodesk Inc.). The CAD models were then imported into a pre- and post-processor (LS-PrePost, 4.9, ANSYS) to create in silico RBFDP models. A non-linear explicit dynamic finite element analysis was conducted to simulate the load-to-fracture test of single-cantilevered RBFDPs.
[Results and Discussion]
KATANA Zirconia YML consists of enamel, body 1, body 2, and body 3 layers with densities of 6.04, 6.05, 6.06, and 6.07 g/cm³, respectively, and fracture strains of 0.0055, 0.0081, 0.0086, and 0.0082. Their respective elastic moduli were 101.85, 105.49, 104.75, and 103.00 GPa. The PDP model demonstrated the strongest fracture resistance, followed by NP, P, and PD, with a fracture load of 758.62, 742.94, 695.61, and 689.16 N, respectively. In summary, the connector thickness and the loading point are important parameters to consider when designing single-cantilevered RBFDPs.
[Reference]
1) Inokoshi M, Liu H, Yoshihara K, et al. Layer characteristics in strength-gradient multilayered yttria-stabilized zirconia. Dent Mater 2023; 39(4): 430-41.