PFM crowns are metal crowns consisting of a layer of porcelain fused on the metal. This makes them almost as durable as pure metal crowns but with a lot more aesthetic. These crowns are among the popular choices for crowns or bridges, especially for front teeth dental restorations. PFM restorations are constructed with a metal interior and a porcelain exterior and between PFM crown vs ceramic they are more cost-effective than all-ceramic crowns.
These are classified into three different categories of metal alloys used. They are:
- Base/ Non-precious: These consist of approximately 20 to 25 percent of precious metal material while the rest is mainly chromium, nickel and others. This may be the strongest metal alloy, however some people have experienced inflammation in the gums due to the metals used in it. There are no systemic reactions or impact on general health in general, but there have been some cases that there may be an allergic reaction to the material being used.
- Noble/ Semi-precious: These consist of a lower content of precious metals such as gold and platinum. Typically, it will be approximately 40 percent. This helps to bring down the cost while also maintaining a good level of strength.
- High noble/Precious: These have about 60 percent of gold, palladium or platinum. A porcelain fused metal crown cannot be made up of pure gold because it is too soft to work with. Even though this is the most expensive porcelain fused metal, it is also the most reliable when it comes to durability concern.
Advantages of porcelain fused metal crowns:
- Visually appealing: Porcelain fused to metal crowns offer you a natural and attractive smile as porcelain can be matched to the color of the surrounding natural teeth while also having similar visual properties.
- Longevity, strong and durable: Metal and porcelain both are extremely durable dental materials that can easily endure the stress of chewing and can last many years of wear and tear.
- Affordability: Porcelain fused metal crowns are more cost-effective crowns while also providing the visual benefits of an all-porcelain crown.
Disadvantages of porcelain fused metal crowns:
- Dark lines: even though porcelain fused metal crowns have a porcelain exterior, they still contain metal which presents a dark line where the tooth meets the crown as it is visible at the bottom of the crown.
- Possible allergies: Patients who have metal allergies or are sensitive to metal may have an allergic reaction to these crowns.
- Removes more natural tooth structure: In order to place this crown, a considerable amount of natural tooth structure needs to be removed.
Indications:
- Ideal for the restoration of anterior and posterior crowns and bridges.
- a retainer for fixed partial denture.
- Implant crowns & bridges, cemented or screw-retained.
- Cases needing precision attachments, when teeth need to be completely covered for esthetic demand or if minimal interocclusal space is available.
Contraindications:
- Teeth with large pulp due the possibility of pulp exposure during preparation or short crowns.
- Highly esthetic cases with minimal prep reduction.
- Restorations to match highly translucent teeth or all ceramic crowns on adjacent teeth.
- Patients with allergies and specific alloy sensitivities.