The effect of different core/veneer thickness ratio on stress distribution of implant-supported zirconia-ceramic posterior crown: a 3-D finite element analysis

• Main Authors: Hui-Ling, Chen, 陳惠菱
• Other Authors: Ming-Lun, Hsu
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/y8z8kf

碩士 === 國立陽明大學 === 牙醫學系 === 103 === Purpose To evaluate the effect of different core/veneer thickness ratio on stress distribution in implant-supported zirconia-ceramic posterior crown. Materials and methods Nonlinear contact finite element analysis was used to evaluate the stress distribution in zirconia-ceramic crown under axial and oblique loading. The implant-supported maxillary first molar crown was constructed with 3mm occlusal thickness. Five models with different core/veneer thickness ration were as follows: model I 0.2 (0.5 mm/ 2.5 mm), model II 0.5 (1 mm/ 2 mm), model III 1 (1.5 mm/ 1.5 mm), model IV 2 (2 mm/ 1 mm), model V 5 (2.5 mm/ 0.5 mm). The 1st principal stress and von Mises stress were analyzed to observe the effect of different core/veneer thickness ratio on stress distribution. Results Either under axial loading or oblique loading, the different core/veneer thickness ratio only affected the stress distribution in the core and veneer layer. The results of 1st principal stress showed that the stress dissipation decreased as the core/veneer thickness ratio increased. The stress generated by oblique loading was greater than axial loading. Under axial loading, the model V showed relatively higher maximum von Mises stress magnitude but other models had no significant difference. As for oblique loading, the model V also showed relative higher maximum von Mises stress magnitude. Besides, the model III and IV revealed relatively favorable stress magnitude in comparison with other models. Conclusion The different core/veneer thickness ratio in zirconia-ceramic crown had influence on the stress distribution on crown but not the implant component or supporting bone structures. Under axial loading, the core/veneer thickness ratio as 5 is unfavorable for stress distribution. The core/veneer thickness ratio with 0.2, 0.5, 1 and 2 showed no obvious difference. As for oblique loading, the core/veneer thickness ratio as 1 and 2 is relatively favorable for stress distribution.