Cosmetic Dentistry Blog Cosmetic and General Dentistry Questions Answered

March 7, 2019

All ceramic vs porcelain-fused-to-gold crowns


We thank our advertisers who help fund this site.

Dr. Hall
I am having crowns replaced over tooth number 4 & 5. There is, as I believe, no cosmetic value of using pure porcelain versus Crown Porcelain fused to High Noble. There is a significant extra cost of $200.00 per each pure porcelain. In general, would a pure porcelain fused to a High Noble versus pure porcelain be just as effective over the long term?
– Garry from California

Garry,
First, I like to talk about terminology so we know exactly what we are talking about. We should be saying all-ceramic crowns, not all-porcelain. Porcelain is only one of various ceramics that have been used for crowns and even some dentists gloss over this terminology. Few dentists are placing all-porcelain crowns on back teeth these days because they are very technique sensitive and are much weaker than the newer high-strength ceramics, lithium disilicate and zirconia. The eMax crown, which I believe is the most popular crown being used by dentists today, features a lithium disilicate core with porcelain baked over it. Lithium disilicate has reasonable aesthetics—it is white and somewhat translucent—but it comes in blocks and is shaped by milling, so the technician doesn’t have the ability to manipulate the color the way porcelain color is manipulated. Porcelain comes in a paste and it is placed, shaped, and then baked. So the ceramist can apply various colors and translucencies of the paste in different layers over the lithium disilicate core with a great deal of control over the aesthetics.

My guess would be that your dentist is talking about putting all-ceramic crowns on your teeth numbers 4 and 5, which are the first and second premolars on your upper right. So your question is, should you get porcelain fused to high noble (otherwise called porcelain fused to gold) instead.

Cosmetic dentists consider upper first premolars to be in the smile zone on almost all patients. Practically everyone will show that first premolar prominently when they smile. It may not be prominent when you look at yourself straight on in the mirror, but it is very noticeable from the side. For me, I would not want a crown made of porcelain fused to gold or any other metal here because there will be a significant risk of a dark line showing at the gumline. The dark line comes from the metal foundation showing through right at the margin of the crown.

Behind that first premolar, in my smile, the teeth are all in the shadows, so the aesthetics is much less critical there. In my mouth, I do have a porcelain fused to gold crown on one of those teeth. I also have a crown on my upper left first premolar, and that crown is an eMax.

So my answer is that I disagree that there is no cosmetic value here. Having said that, if you were my patient and wanted the porcelain fused to gold crown on your first premolar, I wouldn’t fight you on that. But then I probably wouldn’t have the issue come up because I would charge the same fee for either crown. A porcelain fused to high noble crown is a premium crown, and I charged more for that than for a porcelain fused to noble (semi-precious metal) crown. But I don’t understand why the all-ceramic crown needs to be more than the porcelain fused to high noble.

– Dr. Hall

Do you have a comment or anything else to add? We’d love to hear from you. Enter your comment below.

Click here to ask Dr. Hall a question of your own.

About David A. Hall

Dr. David Hall was one of the first 40 accredited cosmetic dentists in the world. He practiced cosmetic dentistry in Iowa, and in 1990 earned his accreditation with the American Academy of Cosmetic Dentistry. He is now president of Infinity Dental Web, a company in Mesa, Arizona that does complete Internet marketing for dentists.

January 21, 2016

Allergic to her Maryland bridge

We thank our advertisers who help fund this site.
.

Dr. Hall,
I have recently had #24 [lower central incisor] pulled due to the gum receding. My dentist had a Maryland bridge made and I am allergic to it. What other options are there? There is not enough room for an implant. The periodontist suggesting removing #25 and replacing with one tooth but I fear I will look more like a side show attraction than I already do. HELP… Am searching for answers.
– Ann from Texas

Ann,
I had to laugh when I heard the suggestion of your periodontist, of taking out the adjacent tooth also and then replacing the two teeth with one large tooth. That sounds so much like a typical dentist and so out of touch with what a patient would want. I agree with you that you could look like a side show. But another option similar to this would be to place one implant supporting two teeth—that can be done also.

A Maryland bridge consists of a porcelain tooth bonded onto a metal framework. The framework has metal wings which are bonded to the lingual side (inside surfaces) of the two adjacent teeth. In order to bond properly, that metal has to be etched. The etching produces microscopic irregularities in the surface that make the metal bond well to dental bonding resins. And there are two ways to make that metal etchable.

One is to use an alloy that contains 1-2% beryllium. Usually that metal also contains nickel and chromium as primary components, but it doesn’t have to. The problem with such an alloy is that about 10% of the population will have an allergy or sensitivity to the alloy. That allergy could be to any of these three components, or all of them, as all are known to provoke sensitivity reactions in some people.

The other way to create an etchable surface on the metal is to plate the metal with tin. When that is done, a semi-precious alloy can be used—one that is made of maybe palladium and silver. Such an alloy is hypoallergenic. The alloy itself isn’t etchable, but the tin plating is. So that is an option for you.

A final option would be to make the bridge out of zirconia. Zirconia is a metal oxide, a compound of the metal zirconium plus oxygen, and is extremely strong. It is a ceramic and is white and translucent, similar to porcelain. Some people call it “ceramic steel.” And it can be etched so that it bonds to dental bonding resin. This, to me, is a better way to go. Not only does it eliminate the sensitivity problem, it is more esthetic since there is no metal to darken the adjacent teeth.

– Dr. Hall

Do you have a comment? We’d love to hear from you. Enter your comment below.

Click here to ask Dr. Hall a question of your own.

About David A. Hall

Dr. David Hall was one of the first 40 accredited cosmetic dentists in the world. He practiced cosmetic dentistry in Iowa, and in 1990 earned his accreditation with the American Academy of Cosmetic Dentistry. He is now president of Infinity Dental Web, a company in Mesa, Arizona that does complete Internet marketing for dentists.

Powered by WordPress

Follow this blog

Get every new post delivered right to your inbox.


Categories