IADR Abstract Archives
Shape Optimization Of Maxillary Anterior Resin-Bonded Fixed Partial Dentures
Objectives: The aim of this study is to optimize the shape of resin-bonded fixed partial dentures (RBFPD) for maxillary anterior region using an automated manner within the framework of finite element (FE) analysis.
Methods: A 3D geometric model consisting a left central incisor and a canine in the associated maxillary segment was constructed from images of CBCT. A RBFPD which restored missing lateral incisor was designed using Solidworks. The tooth model combining RBFPD was meshed, assigned boundary conditions and loaded (F=500N) at lingual surface of the lateral incisor using Hypermesh. The FE model was then solved using ABAQUS to obtain the tensile stresses at all interfaces. The optimization process based on the genetic algorithm was developed to iterate the above mentioned procedure. Retainer’s shape would be adjusted in each iteration for minimizing the total interfacial stress.
Results: Three types of different retainer designs, circular, rectangular and full-covered ones were evaluated. Looking at the upper distal lingual interface between enamel and retainer, the average interfacial tensile stress occurred in the circular one was 2.46MPa, which was significantly smaller than that occurred in the rectangular one (56.1MPa) and in the full-covered one (3.56MPa). Size effect was evaluated for the circular and rectangular designs. Both the maximal von Mises stress and the interfacial average tensile stress decreased when reducing the rectangular retainer’s size. On the contrary, reducing the circular retainer’s size resulted in increasing of both stresses.
Conclusions: A semi-automatic process was successfully developed and performed to iterate the modeling process of various RBFPD’s retainer design. The results suggested the circular retainer would perform better than other designs. Reducing the retainer’s size could improve or worsen the stress results depending on which type of shape design is considered. With further development, the framework can iterate toward the optimal retainer design that results in minimum total interfacial stress.
Methods: A 3D geometric model consisting a left central incisor and a canine in the associated maxillary segment was constructed from images of CBCT. A RBFPD which restored missing lateral incisor was designed using Solidworks. The tooth model combining RBFPD was meshed, assigned boundary conditions and loaded (F=500N) at lingual surface of the lateral incisor using Hypermesh. The FE model was then solved using ABAQUS to obtain the tensile stresses at all interfaces. The optimization process based on the genetic algorithm was developed to iterate the above mentioned procedure. Retainer’s shape would be adjusted in each iteration for minimizing the total interfacial stress.
Results: Three types of different retainer designs, circular, rectangular and full-covered ones were evaluated. Looking at the upper distal lingual interface between enamel and retainer, the average interfacial tensile stress occurred in the circular one was 2.46MPa, which was significantly smaller than that occurred in the rectangular one (56.1MPa) and in the full-covered one (3.56MPa). Size effect was evaluated for the circular and rectangular designs. Both the maximal von Mises stress and the interfacial average tensile stress decreased when reducing the rectangular retainer’s size. On the contrary, reducing the circular retainer’s size resulted in increasing of both stresses.
Conclusions: A semi-automatic process was successfully developed and performed to iterate the modeling process of various RBFPD’s retainer design. The results suggested the circular retainer would perform better than other designs. Reducing the retainer’s size could improve or worsen the stress results depending on which type of shape design is considered. With further development, the framework can iterate toward the optimal retainer design that results in minimum total interfacial stress.
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