In esthetic rehabilitation, methods used to enhance the margin quality have always been the focus and difficulty of improving the level of diagnosis and treatment, prevention and treatment of complications, and collaboration between clinicians and technicians. However, it is impeded by the ambiguous definition and classification of margin, unstandardized tooth preparation, manufacturing process of restoration, and lack of reliable means of checking the quantitative requirements of preparation or restoration. The digital technologies that are increasingly applied, such as intra-oral scanner, impression scanner, and computerized numerical control cutting machine, have strict requirements about margin quality. Failure of recognizing margins by these scanners will hinder the digital process of diagnosis and treatment. Even if these sharp and narrow margins are successfully scanned, they cannot be milled accurately. To overcome these problems, this article demonstrated the clear and complete definition of preparation margin and restoration margin, as well as their subclassifications, by analyzing the target restoration space from a geometric perspective. Practical approaches to measuring the margin width and inspecting the margin quality were proposed. The new and full understanding and proposal about preparation margin and restoration margin characterized by measurements will effectively support the thoroughly digitalized process of esthetic rehabilitation using porcelain in fixed prosthodontics, which is based on the guidance of values.
瓷美学修复是固定修复的热点，如何提升其边缘修复效果一直是瓷美学修复诊疗水平提升、相关并发症防治的重点以及医技合作的难点。但长期以来固定修复中对边缘的定义与分类、预备术以及制作工艺、质检等还存在诸多不完整的认知，医技统筹合作不足，而实操中医生或技师常常也缺乏核查牙体预备磨切量、预备体与修复体外形形态的可靠方法，大多依赖目测观察和个人经验。这些认知和医技实操的模糊欠缺，使得当前固定修复的边缘质量难以获得进一步的提升。随着数字化诊疗及制作技术在瓷美学修复中的大量运用，数字化牙科扫描及数控切削对边缘质量提出了更高更明确的要求，无法被扫描识别的边缘，无法信息化，再便捷的数字化流程也无法进行下去；不符合数控加工规范的过薄过锐的边缘即使扫描成功，也无法准确切削。为了更好地解决上述难题，有效提升边缘质量，集合了参与专家的共同意见，本文将从边缘涉及的不规则微小目标修复体空间的分析设计梳理入手，采用口腔立体几何“线—面—体”视角，定义了预备体边缘和修复体边缘“两个边缘”的内涵，并对8个亚分类概念进行解读，进一步提出可及性好的两个边缘宽度的实测方法，以及临床和制作的质检实测核查方案。以实测核查几何量—目标修复体空间为特征的两个边缘的新认识与新方案，将对全程数字化瓷美学修复提供更好的支撑。.
Keywords: clinician-patient-technician collaboration; digitalization; esthetic porcelain rehabilitation; physical measurement; preparation margin; restoration margin.