PORCELAIN FUSED TO METAL (PFM)
PFM’s can be thought of as a hybrid between all-metal and all-ceramic dental crowns because they’re made out of both materials.
- A Metal Alloyis used to create a thin thimble-like cap (“substructure”) that fits snugly over the tooth.
- Porcelain is then fused over the substructure to form the shape of the crown and give it a white tooth-like appearance.
Advantages of PFM’s vs. All-Metal Crowns
The clear advantage of a PFM crown over an all-metal one is simply one of appearance.
Its porcelain covering gives it a tooth-like look. And for teeth that hold a prominent position in your smile, that can be a vitally important factor.
Advantages of PFM’s vs. All-Ceramic Crowns
Just like with PFM’s, all-ceramic restorations give a natural-tooth look too. But beyond that similarity, metal-ceramic restorations offer some advantages.
Greater strength: Due to their metal substructure, PFM crowns are the stronger type of restoration.Even if some of its surface layer of porcelain fractures off, the metal substructure underneath will characteristically stay intact thus maintaining the crown’s seal over, and reinforcement of the tooth.
A more precise fit: Due to differences in how they’re made, a PFM’s metal substructure typically achieves a more exacting fit over its tooth than an all-ceramic one.
Admittedly, on a clinical level this may only be of limited concern. But at least in theory, the less dependence the tooth-to-crown relationship has on its weakest link (the cement layer in between) the better.