I’m often asked, ‘What’s the best crown material?’ In my eyes, hands down, the best crown material is porcelain from a health and biocompatibility point of view. So, between the two most popular types of crowns in dentistry today, I always recommend a full porcelain crown over a PRM crown for my patients.
The main reason is that my patients care about the materials that are used in their mouths, and want the most biofriendly materials possible. The second reason is I often see the results of PFM crowns on the health of the gums around the tooth that has this type of crown. The rest of this article lays out the differnces in these two types of crowns and compares the inflammation produced by a PFM vs an Full Porcelain Crown.
What is a PFM crown?
PFM stands for porcelain fused to metal. It’s a crown that was the most commonly used from the 1980’s until around 2010. The reason why it was used so often is that it is reliable and long lasting. That’s why I call it the Cadillac of crowns. It has stood the test of time.
How it’s made is that a lab casts a metal coping that fits over the tooth and looks kind of like a thimble. Then the lab bakes different kind of porcelains over the metal to give it a fairly natural appearance when the crown is on the tooth. I say fairly natural because these crowns have an opaque look to them because of the masking that’s needed to hide the metal under the porcelain.
Here is a PFM crown showing the metal part that covers the tooth and the porcelain that is layered on the outside that is the natural looking part of the crown. I used this example because you can clearly see the metal. The porcelain would be visible when you smile and not the metal, so it’s more cosmetic that a straight metal crown.
Advantages and Disadvantages of PFM Crowns
The advantages of a PFM crown is that it is fairly cosmetic when compared with a full metal crown or gold crown. It is also very long lasting as the average lifespan of this kind of crown is around 25 years.
The disadvantages of a PFM crown are that you don’t want them on your front teeth as they are opaque and will make your front teeth look like ‘chicklets’ as they are called. The second disadvantage is that they commonly cause inflammation in the gums.
Why gums are grey around a PFM Crown?
Over time, a lot of people can develop sensitivities to different types of metals. Many of my patients have commented that they react to different types of metals in their rings, earrings, etc. The same thing can happen with metals when they are used in dentistry. When gums come in contact with the metal in PFM crowns, they generally look inflammed and ‘grey.’
I’ve looked at hundreds of dental materials tests over the years, and nickel causes reactivity in our immune cells. Nickel is a main component of stainless steel, which is commonly used in othodontic brackets, wires as well as metal crowns. Another common metal used in crowns is palladium, which also causes reactivity.
Here is a picture of a PFM crown. See the porcelain covering the metal underneath it, except for a thin band of metal down by the gums. As the arrows point out, there is a collar of grey gingiva or gums around the metal collar of the crown. This can be seen quite often around this type of crown.
Also, look at how opaque the crown looks compared to the tooth next to it. Most people would not like this look in the front of their mouth and in their smile line. It doesn’t look good in pictures!
Video of Plaque Sample around a PFM Crown
Below is a video of a plaque sample from around a PFM crown The large number of white blood cells (WBC’s), or leukocytes as they are called, are a sign of inflammation. This immune reaction by the body is most likely due to the metal of these crwons, as I don’t usually see this around all porcelain crowns. This video documents the immune reaction.
Advantages of a Full Porcelain Crown over a PFM
One advantage of a Full Porcelain Crown (FPC) over a PFM is that it’s more cosmetic; in other words it looks more natural. Therefore, you can use them on front teeth and in your smile line. With FPC’s light penetrated deeper into the porcelain and gives it a much more pleasing look compared with PFM’s, where porcelain has to mask the metal underneath it.
Here is a FPC on a second tooth from the same patient’s mouth. As you can see the gums look much better than the gums around the PFM crown above. There is not a grey collar in the gums around this tooth. In fact they look pink and healthy. This is because porcelain is much more biofriendly than many metals used to make PFM’s.
Video of Plaque Sample around a Full Porcelain Crown
The microscope video below shows the plaque around an all porcelain crown and the fact that there is virtually no bacteria or plaque around this tooth. This is why I do all porcelain crowns in my practice. Porcelain is a biofriendly dental material vs other materials dentists have used in the past like metal crowns and metal fused to porcelain crowns.
Conclusion
As you can tell from the above video, I much prefer Full Porcelain Crowns over PFM’s in my practice. So do my patients as they are holistic.
Keep your eyes peeled for my next post on a special type of porcelain crown crown that I am making for the patients in my practice. This is a technique that most dentists don’t even know is possible in todays digital crown environment, and it’s different from the usual Emax or full Zirconia crowns available in the marketplace today.
Carey O’Rielly DDS has been a practicing dentist for 35 years. He went to USC Dental School and Duke University for his undergraduate degree. He grew up in Laguna Beach and now lives in La Costa with his wife Victoria, who runs his office.
He began his career by owning and operating a network of six offices in the San Francisco Bay Area. Presently he owns a private holistic practice in North County San Diego’s Encinitas.
Dr. O started looking for solutions to his health challenges that resulted from the stress and environmental toxicity that built up over a ten year period running his dental network. He has dedicated himself to learning about oral systemic problems and how dentistry can affect your health. He has applied what he has learned over the last twenty years to ensure he, his staff and his patients are protected from the chemicals and toxic materials found in most dental offices. He has produced an environmentally friendly office that is also peaceful and calm.
He is an expert on dental materials having looked at hundreds of biocompatibility lab tests over the years. He has identified the most bio-friendly materials to use in his practice and which dental materials can be used to replace metal fillings and crowns, including BPA free and fluoride free ‘white’ fillings. He also uses metal-free Zirconia or ceramic implants and PRF (platelet-rich fibrin) grafting materials which come from the patient’s own blood.
Dr. O’Rielly teaches C.E. courses on the systemic effects of gum disease. He is an expert in using phase contrast microscopy for analyzing dental infections, where he shows patients what kind of microbes, i.e. bacteria, amoeba, and yeasts like candida are populating the mouth and affecting the body as a whole.
He has an educational blog and is writing a book on dental health called ‘Hidden Dental Infections: Healing Root Canals and Infected Teeth with the Erbium Laser’ where he discusses dental nutrition, toxic dental materials and the effects of old root canals on inflammation and overall health.
