A PFM crown is a porcelain-fused-to-metal crown, a type of dental cap with a metal inner shell covered by a layer of tooth-colored porcelain. For decades, it has been considered the gold standard for restoring damaged or decayed teeth because it combines the strength of metal with a natural-looking exterior. PFM crowns typically cost between $800 and $2,400, with an average around $1,100.
How a PFM Crown Is Built
A PFM crown has two layers. The inner framework is a thin metal shell custom-fitted to your prepared tooth. This shell is then coated with porcelain that’s color-matched to your surrounding teeth and fired at high temperatures so it bonds to the metal. The result is a crown that looks like a natural tooth on the outside but has the structural backbone of metal underneath.
The metal framework can be made from different alloy categories. High noble alloys contain a high percentage of gold, platinum, or palladium and are the most biocompatible. Noble alloys use a mix of precious and non-precious metals. Base metal alloys, the most affordable option, are typically made from nickel-chromium or cobalt-chromium. The alloy your dentist recommends affects cost, durability, and your risk of allergic reaction.
What Getting One Involves
Your dentist reshapes the tooth to make room for both the metal layer and the porcelain layer on top of it. This means removing more tooth structure than you’d lose with some other crown types. For a front tooth, about 2mm is trimmed from the biting edge and 1mm or more from the other surfaces. Back teeth need 1.5 to 2mm of clearance on the chewing surface so the crown doesn’t interfere with your bite.
After reshaping, your dentist takes an impression (either digital or with putty) and sends it to a dental lab, where technicians fabricate the metal framework and layer porcelain over it. You’ll wear a temporary crown for one to two weeks while the permanent one is made. At the second appointment, the temporary comes off, and the PFM crown is checked for fit, bite alignment, and color before being cemented in place.
Where PFM Crowns Work Best
PFM crowns are most commonly placed on back teeth, particularly premolars and molars, where chewing forces are highest. The metal substructure handles heavy bite pressure well, while the porcelain exterior keeps the tooth looking natural when you smile or open your mouth wide. They’re also used for dental bridges, where a false tooth is suspended between two crowned teeth, because the metal framework provides the rigidity a bridge needs.
For front teeth, PFM crowns are functional but not always the first choice today. The metal layer underneath can block light from passing through the porcelain the way it would through a natural tooth, making the crown look slightly opaque compared to your other teeth. All-ceramic crowns tend to mimic the translucency of natural enamel better, which is why many dentists now prefer them for the most visible teeth.
How Long They Last
A well-made PFM crown on a healthy tooth can last 10 to 15 years or longer with good oral hygiene. A study tracking PFM crowns placed at an Australian university dental clinic found a survival rate of 83.2% over five years. Among the crowns that failed in that study, the most common outcome was that the crown needed to be replaced or removed (about 58% of failures), followed by the underlying tooth needing extraction (about 32%). A small percentage simply came loose and had to be recemented.
The porcelain layer is the most vulnerable part. It can chip or fracture if you bite down on hard objects, grind your teeth at night, or take a blow to the face. When a chip is small, your dentist can sometimes repair it with composite resin. Larger fractures usually mean replacing the entire crown. The metal underneath rarely fails on its own.
The Dark Line Problem
The most recognized cosmetic drawback of PFM crowns is a grayish line that can appear along the gum line over time. This isn’t staining or decay. It’s the metal edge of the crown becoming visible as your gums naturally recede with age. In some cases, the bond between the metal and porcelain also weakens over the years, making the contrast between the two materials more noticeable.
Not everyone develops a visible dark line, and it tends to be more of a concern on front teeth where others can see it. Some labs use a porcelain margin technique, extending the porcelain all the way to the edge of the crown so no metal is exposed at the gum line. This reduces the risk but adds complexity and cost to fabrication. If you already have a PFM crown with a dark line, the only fix is replacing it, often with an all-ceramic crown.
PFM Crowns vs. All-Ceramic and Zirconia
PFM crowns held their position as the default choice for decades, but newer materials have changed the conversation. Here’s how they compare:
- Aesthetics: All-ceramic crowns look more like natural teeth because light passes through them similarly to enamel. PFM crowns can appear slightly opaque, and they carry the risk of a dark gum line.
- Strength: Zirconia, the strongest all-ceramic option, has a flexural strength of 900 to 1,200 MPa, making it comparable to or stronger than many PFM combinations. PFM crowns still perform well under heavy bite forces, but they no longer hold a clear strength advantage over modern zirconia.
- Tooth preservation: PFM crowns require more tooth removal to accommodate both the metal and porcelain layers. Some all-ceramic options can be made thinner.
- Cost: PFM crowns are generally less expensive than high-end zirconia or pressed-ceramic crowns, which is one reason they remain popular.
Metal Allergies and PFM Crowns
If you have a known sensitivity to metals, particularly nickel, a base metal PFM crown could cause problems. Nickel is the most common metal sensitizer in dentistry, and nickel-chromium alloys are widely used in less expensive PFM frameworks. Women are four to ten times more likely than men to have a nickel sensitivity. Chromium allergies are rarer, affecting roughly 10% of men and 3% of women who are tested.
Reactions can include gum inflammation, a burning sensation, or a rash on the skin near the mouth. If you’ve ever had a reaction to costume jewelry, belt buckles, or watch backs, mention it to your dentist before choosing a crown material. High noble alloys (gold-based) are far less likely to trigger a reaction. All-ceramic crowns eliminate the metal allergy concern entirely.
Cost and Insurance Coverage
PFM crowns sit in the mid-range for crown pricing. The $800 to $2,400 range depends on the alloy used (gold-based costs more than nickel-chromium), where you live, and the complexity of the case. Private dental insurance typically covers medically necessary crowns at about 50% of the cost, though you’ll usually need to meet your annual deductible first. Some plans cap the amount they’ll pay per crown regardless of the actual charge, so checking your specific benefits before committing is worth the phone call.