FAQ

What is a feather edge margin?

A straight answer first, then the context behind it, from the technicians who do the work.

THE SHORT ANSWER

A feather edge margin (also called a knife-edge margin) is a preparation finish line where the tooth tapers to a very thin, indistinct edge at the gingival boundary. It leaves no defined ledge for the restoration to seat against. Labs typically use this margin design for full-cast metal crowns and Maryland bridges, where minimal tooth reduction is clinically acceptable.

THE CONTEXT

What sits behind it

Feather edge preparations reduce the amount of tooth structure removed at the margin, making them conservative. The tradeoff is precision. Without a defined shoulder or chamfer, the technician has limited reference geometry for seating the restoration accurately. At Dani Dental, every case with a feather edge margin is flagged during the case intake review so the fabricating technician can confirm the scan captures the finish line before milling begins.

For prosthodontists and restorative-focused general dentists working in metal or metal-ceramic, feather edge margins are a legitimate clinical choice in specific zones. Posterior full-cast crowns in low-esthetic corridors and resin-bonded bridges are the two most common use cases. Anterior ceramics and full-zirconia restorations almost never call for a feather edge because the ceramic thickness needed at the margin for structural integrity requires at least a chamfer or a shoulder preparation.

If you are sending a feather edge case, include a periapical radiograph alongside the intraoral scan or PVS impression. The radiograph gives the technician a second reference plane to locate the finish line without guessing. Cases submitted with that combination average fewer remake requests and ship within our standard 7-10 business day window.

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What is a feather edge margin?
A feather edge margin (also called a knife-edge margin) is a preparation finish line where the tooth tapers to a very thin, indistinct edge at the gingival boundary. It leaves no defined ledge for the restoration to seat against. Labs typically use this margin design for full-cast metal crowns and Maryland bridges, where minimal tooth reduction is clinically acceptable.

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