Title: 0870 - Effect of Different Materials/techniques on Stresses in CAD/CAM Endocrowns
Gurcan Eskitascioglu, Pi Academy
Oguz Eraslan, Selcuk Universitesi
Sema Belli (Presenter)
University of Selcuk
Objectives: Computer aided design/manufacturing (CAD/CAM) endocrowns are widely used for the restoration of root-filled teeth with extensive structure loss. Monolythic or multilayer structures may be used for this purpose. Restorations made with multilayering technique may mimic natural teeth better. The aim of this finite elemental stress analysis (FEA) study was to evaluate the effect of different materials/techniques on stresses in CAD/CAM endocrowns.
Methods: A 3-Dimensional mathematical model simulating an endodontically treated mandibular first molar was modeled. The model was then modified to simulate molar tooth restored with ceramic endocrown. Three FEA models were then created from this main model to simulate the following endocrown structures: 1: lithium disilicate reinforced glass ceramic, 2: monolytic zirconia, 3: multi-layered glass ceramic and glass-fiber endocrown (the core structure was composed of glass-fiber while the crown is prepared by glass ceramic). The SolidWorks/Cosmosworks structural analysis program was used for FEA analysis. Materials used in the study were assumed to be homogenous and isotropic. A 300 N load was applied from the occlusal surface of the restoration. Results were presented by considering von Mises criteria.
Results: The von Mises stresses which were recorded at the cavity base were 0.417-0.700 MPa, 0.600-0.850 MPa and 0.083- 0.250 MPa respectively. Multilayering technique reduced the stresses when compared to the other two different design and materials and showed similar stress distributions with natural tooth model. Models which were assumed to be restored with zirconia endocrown showed the highest stresses.
Conclusions: Multilayering technique using with fiber reinforced glass ceramic as a core and glass ceramic as a crown reduced the stresses in this study and showed stress distributions similar to natural-tooth. This technique can be used to create biomimetic restorations with a core material which mimics dentin (glass-fiber reinforced ceramic) and crown material which mimics enamel (glass ceramic).
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: This study was performed in Research Center of Dental Faculty of Selcuk University and supported in part by Scientific Research Projects Coordination Center (BAP) of Selcuk University, Konya, Turkey.