Principles Of Tooth Preparation Practice Test

The margin design that provides a distinct margin is chamfer. A chamfer creates a rounded, clearly visible finish line around the prepared tooth, producing a crisp, continuous boundary between tooth structure and restoration. This makes the margin easy to locate and reproduce in impressions and on the tooth itself, which is essential for accurate seating and esthetic outcomes. A feather-edge margin tapers to a knife-edge, resulting in a margin that is difficult to see and control, so it does not offer a distinct margin. A gingival bevel is a bevel at the gingival edge used mainly for esthetic or veneer-related purposes and does not provide the same clearly defined finish line for a full-coverage crown. A shoulder margin also presents a distinct edge but is bulkier and involves more conserved tooth structure; chamfer achieves a clear margin with a balance of visibility and conservation, which is why it is identified as providing a distinct margin.