定制化钛合金假体能实现人体骨组织个性化修复与重建,在骨科和颌面外科中具有重要应用,但其修复和重建效果受制造工艺-特别是快速铸造工艺-精度的影响.由于定制化假体的快速铸造精度强烈地依赖于假体结构的复杂程度,为研究钛合金假体的快速铸造工艺精度,以形状较为复杂的定制化下颌骨假体为研究对象.对其制造过程的误差源进行分析.为便于测量,建立简化的下颌骨假体模型.根据下颌骨假体结构特征建立两种收缩模型,并分析理论收缩率.通过光固化快速成形、快速铸造试验和对铸件的反求建模,将其与原始设计模型进行对准和比较测量,研究工件在不同方向的收缩变化规律,对理论收缩率进行验证,建立精度补偿机制.通过下颌骨实际病例假体的制作和测量,验证精度补偿机制的有效性.研究结果对定制化假体的快速制造具有重要的参考意义,可广泛应用于在临床案例假体的制造.
Customized titanium alloy prosthesis can be used precisely and personally for the repair and reconstruction of human bone tissue,thus has an important application in orthopaedic and maxillofacial surgery.However,its effect is affected by the accuracy of manufacturing process,especially affected by the deformation of rapid casting.Therefore,a complex mandibular prosthesis is used for the study of manufacturing accuracy.The error sources of the manufacturing process for the customized prosthesis are analyzed.A simplified model of the mandibular prosthesis is built up.According to the structural characteristics of mandibular prosthesis,two casting shrinkage models are established and analyzed for the theoretical shrinkage.Through stereolithography,rapid casting experiment and reverse modeling of the casting of prosthesis,the reversed model is aligned with the original model and their dimensions are compared for getting the 3D shrinkage patterns.The mechanism of dimension compensation is built and the theoretical shrinkage is verified.The compensatory mechanism is verified through the mandibular prosthesis fabrication for clinical cases.The results confirm the effectiveness of dimension compensation mechanism and might have referencing significance to the rapid manufacture of customized prostheses for clinical application.