Introduction: Complex occlusal loading and crown geometry have effects on the damage initiation and accumulation on all-ceramic dental crowns. This study developed an FEA mode to evaluate the influence of loading type and crown geometry on the stress development and distribution in all-ceramic dental crowns. Materials and Methods: A 3D solid model (Pro/Engineer) of a ceramic-cement-tooth layered structure was developed. Perfect cementation between layers is assumed. A sensitivity analysis was performed (perturbation method) to identify critical parameters. A 200 N force was applied either on the central fossa or on the inner cuspal incline of the crown. Results: Sensitivity analysis indicates that thickness of the cement layer, the incline cuspal, and the load direction are all-important. Offset loading from the central fossa changes the maximum principal stress from radial and cone crack pattern to open model I or mode III crack pattern along the circumferential margin. The offset loading increases the smax-principal by 50% compared with central loading. An empirical model which represents smax-principal as a function of the test parameters and with offset loading condition is given bywhere X1 and X2 represents the cement thickness and the cuspal incline angle. Conclusion: The loading condition significantly influences the stress distribution pattern. A thick cement layer increases the magnitude of smax-principal. This effect would be magnified when the slope of the crown occlusal surface is at a lower angle.
P01DE10976-07
10:15 AM-11:30 AM, Friday, 12 March 2004 Hawaii Convention Center Exhibit Hall 1-2
Back to the Dental Materials: III - Ceramics and Cements Program
Back to the IADR/AADR/CADR 82nd General Session (March 10-13, 2004)