Porcelain Crowns: Frequently Asked Questions

Cosmetic Dentist Serving San Jose, Sunnyvale and the Bay Area

What causes the black line around crowns?

This usually means the crown is a PFM, porcelain fused to metal, crown. When gums recede the edge of the crown is exposed and the black line is the metal part of the crown. All-ceramic crowns eliminate this problem. A dark area near the gums may also indicate the tooth has had a root canal.

Are all porcelain crowns the same?

NO! There are two main groups of porcelain crowns: (a) crowns with metal reinforcement (called a coping) and (b) crowns without metal reinforcement.

Porcelain crowns with metal – Porcelain is fused to the underlying metal. These crowns are known as Porcelain Fused to Metal crowns or PFMs. Many different types of metal and porcelain are used in this type of crown. The porcelain can be fused to non-precious metal, semi-precious metal, or precious metals such as gold or platinum. Each type has different characteristics. These are very strong crowns, but may show a black line when the metal is exposed due to gum recession.
Porcelain crowns without metal – These are known as all-ceramic crowns and are divided into two basic groups, homogeneous and non-homogeneous. A homogeneous crown is made of a uniform and consistent type of porcelain throughout the entire crown. A non-homogeneous crown always has a ceramic core layered with porcelain that is different from the core porcelain. These crowns are very strong and rival PFMs for strength.

All-ceramic crowns tend to be more esthetic than PFMs and usually require a special cementation procedure called bonding. These crowns are much more technique-sensitive than PFMs and are more expensive.

Why are crowns used in dentistry instead of fillings?

Crowns are used in dentistry to restore a tooth that is severely damaged due to decay or fracture. Fillings are used primarily to restore small defects.

How long will a crown last?

This is almost the same as asking how long will my teeth last. With good oral hygiene and regular visits to your dentist, they will last a long time. In many cases they can last as long as 50 years.

Porcelain Crowns

If you would like to learn more about porcelain crowns or any of the procedures or treatments Dr. Wayland provides, or if you would like to find out what cosmetic dentistry techniques he can use to correct your smile, contact him today to schedule your initial consultation.