Abstract: For the transition fusion problem of the inner and outer crown in the digital design of full-coverage crown dentures, a new mesh transition algorithm was proposed. First, mesh boundaries of the inner and outer crowns were extracted to form closed holes by bridging. Then holes were filled by triangular facets according to the definition of inserting rules, and the initial transition meshes were structured. Finally, the initial transition meshes were projected onto the implicit surface obtained by the boundary interpolation, and new transition meshes were structured by projection points, which fused the outer and inner crown topology to form a complete full-coverage crown denture restoration. Meshes obtained by mesh transition algorithm distributed equally, and the quality of triangular facets is good. What's more, transition boundary is smooth, and it has good continuity.

Key words: full-coverage crown denture, mesh transition algorithm, implicit surface, restoration

摘要： 针对全冠义齿数字化设计时外冠和内冠过渡融合的问题，提出了一种新的网格过渡算法。首先提取外冠和内冠网格边界进行桥接形成封闭孔洞；然后根据定义的三角片插入规则插入新的三角片填充孔洞，构造初始过渡网格；最后投影到由边界顶点插值得到的隐式曲面上，投影点构成新的过渡网格，将其与外冠和内冠拓扑合并形成完整的全冠义齿修复体。用过渡算法得到的网格面片分布均匀，三角片质量较好，而且过渡边界光顺自然，具有较好的连续性。

关键词: 全冠义齿, 网格过渡算法, 隐式曲面, 修复体