What is the best marginal tooth preparation?
There is no ideal marginal tooth preparation. The selection of the marginal
design depends on many factors, including:
1. The material used in construction of the full crown:
- All-ceramic restoration—shoulder or deep chamfer
- Metal-ceramic with porcelain extended to marginal edge—shoulder or deep chamfer
- Metal-ceramic with metal collars—shoulder with bevel or chamfer
- Full gold crown—feathered edge, bevel, or chamfer
2. The amount of retention needed: beveled or feathered edge affords the
3. Seating resistance: shoulder preparation affords the least resistance.
4. Sealing capability: beveled or feathered edge affords the best seal.
5.Pulpal consideration: more tooth reduction is necessary with a shoulder
preparation than with a chamfer; the feathered edge requires the least reduction.