Stress analysis and risk of failure during clenching in ceramic assembly models: 3-dimensional finite element analysis

Background/purpose: Clenching is a dental parafunctional disorder that jeopar-dizes the life of teeth and/or dental prostheses. Computer-aided design and computer -aided manufacturing (CAD/CAM)-fabricated or 3-dimensional-printed dental prostheses are aesthetic, strong, and of good quality, but noticeable damage can still be observed after clenching. Stress analysis of synthetic ceramic assemblies with various parameters was con-ducted to provide data that may be used to improve the fabrication of CAD/CAM-fabricated dental prostheses.Materials and methods: Abaqus software was used to run the simulations. A total of 96 axisym-metric finite element ceramic assembly models were simulated under 800 N vertical loading and different contact radii (0.25, 0.5, 0.75, 1.0 mm), materials (IPS e.max CAD and Vita En-amic), layer thicknesses and combinations. Results: Four-layered ceramic assembly models produced promising results with the following parameters: contact radius of at least 0.5 mm, total thickness of at least 0.5 mm, and use of IPS e.max CAD as the first layer and Vita Enamic as the second layer without cement.Conclusion: The ideal four-layered assembly model design uses 0.25-mm-thick IPS e.max CAD as its outer layer to simulate enamel binding and 0.25-mm-thick Vita Enamic as its inner layer to imitate the natural tooth. This design may be used as reference for prosthodontic treat-ment. 2023 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).