基于DFFD的牙齿修复冠约束设计方法的研究

目的：研究口腔修复中患者缺失、损伤牙冠的数字化设计方法，帮助口腔医生快速、灵活、互交地完成修复设计，获得理想的修复牙冠三维数字模型，为数字化制造做准备。方法：在约束条件下利用DFFD(direct manipulation of free-form deformation)修复冠的变形设计方法，完全以患者口腔内的约束条件为基础，通过对特征位置增加、修改、删除约束点和载荷点，然后对其施加拉伸、压缩操作，获得满足临床修复要求的牙冠修复模型。结果：由一个左前一牙齿的变形设计实例证明了此方法的可行性。结论：在患者备牙模型上，按照惠者口腔约束条件，利用DFFD变形设计方法对牙冠的设计是可行的，同时也为外冠桥牙冠数字化设计的研究奠定了基础。

Research of tooth crown constraint design based on DFFD

Objective To explore a digital designing method of for patients whose tooth crown has been damaged, which helps dentists to rapidly and flexibly finish the repair design of tooth crown and to obtain a three-dimensional digital manufacturing mode. Methods This paper introduces the constraint design method of tooth crown based on DFFD(direct manipulation of free-form deformation), which helps dentist use to add, modify, or delete the constraint or load points and then manipulate those feature points to product the good shape of design for the operation of stretching and compressing. Result A design example of the left-front-1 tooth crown proves this method to be feasible. Conclusion The constraint design method of tooth crown based on DFFD is feasible, which is an approach to further researches on the design of the tooth crown bridge.