margin
The boundary or edge of a dental preparation or restoration where it meets the natural tooth structure, determining the fit, seal, and longevity of the prosthesis.
Full Definition
In dental laboratory and clinical contexts, 'margin' (also called 'preparation margin' or 'finish line') refers to the peripheral boundary of a tooth preparation that defines the extent of the crown or inlay. Precise margin delineation on the working cast is fundamental to accurate restoration fabrication. Editors must distinguish 'margin' from 'finish line,' noting that 'finish line' refers to the design of the preparation edge (e.g., chamfer, shoulder), whereas 'margin' can refer to either the preparation edge or the edge of the completed restoration. Both terms appear in the same document and must be used with care.
Usage
Usage note: 'Margin' and 'finish line' are related but not identical; 'finish line' specifies the design geometry of the preparation edge, while 'margin' denotes the physical boundary itself. Clarify author intent when both appear in the same text.
In Context
- "The technician identified the margin on the die with a red die spacer before wax adaptation." — Laboratory Case Notes
- "The manuscript used 'margin' and 'finish line' as synonyms; the editor queried the author to confirm whether both terms were intended distinctly." — Journal Manuscript Editing