The most beautiful crown for a tooth is, without question, all-porcelain or all-ceramic. With porcelain fused to metal crowns, there has to be an opaque layer put over the metal to block out its color. This makes it impossible to have a translucent restoration that mimics the translucency of natural teeth. Only with pure porcelain or pure ceramic can you have such translucency.
To define some terminology, porcelain is a particular type of ceramic that is built by stacking and firing. When we say ceramic, we include porcelain—porcelain is a type of ceramic.
The reason all dentists don’t use all-porcelain crowns for front teeth is that the technique for placing them is very demanding and hasn’t been generally taught in dental schools. They are translucent, and their color is influenced by the color of the underlying teeth. General dentists aren’t usually very skilled at color manipulation in these situations. Also, placing them requires the use of sophisticated bonding techniques that haven’t been fully taught in dental schools. At mynewsmile.com we recommend that if you want one of these beautiful crowns for your front tooth, have it done by an expert cosmetic dentist such as we have listed on our site. See our referral page for referral to an expert cosmetic dentist.
Here is a photograph of a patient’s front teeth. One of these teeth is an all-porcelain crown, done by an expert cosmetic dentist in our referral network. Can you tell which one it is?
The crown is on the patient’s left lateral incisor, the smaller tooth just to the right of the two larger front teeth in our photograph.
The work was done by Dr. Duane Delaune, of Metairie, Louisiana. Notice how closely it mimics the appearance of the natural teeth.
CHOICES IN ALL-PORCELAIN AND ALL-CERAMIC CROWNS
There are various types of all-porcelain or all-ceramic crowns. Let’s explain the differences between some of them:
- Feldspathic porcelain is the standard, traditional porcelain that has been used for crowns for many years. Many cosmetic dentists feel that this is the most beautiful porcelain.
- The Empress crown – Empress is strictly speaking not a porcelain, but is more like a glass. It can be called a ceramic material. The Empress material is cast rather than baked as a feldspathic porcelain crown is. The fit of Empress is more precise than the baked feldspathic porcelain. However, the color in Empress is mostly baked on the outside. Empress can be very beautiful. For appearance’s sake, some expert cosmetic dentists prefer the feldspathic porcelain, and some prefer the Empress.
- The Procera crown – Procera is a milled ceramic on the inside with a more traditional porcelain baked onto the outside. The advantage of Procera is its exceptional strength. However, the milled ceramic core is opaque white, so many cosmetic dentists feel that it isn’t as natural-looking as the more translucent materials. An advantage of Procera is that it doesn’t have to be bonded to the tooth but can be cemented with ordinary crown and bridge cement, a technique familiar to all dentists.
- The Lava crown – Lava is similar to Procera, but the milled ceramic on the inside is a more translucent Zirconia, rather than an opaque white material. The Zirconia is shaded, and then the final esthetics of the crown are achieved in the baked-on outer layer. The Lava crown can also be cemented with traditional techniques. However, any crown cemented with a traditional crown and bridge cement is going to be susceptible to a compromise in the appearance if that cement line ever shows.
- Zirconia crowns, if they are done right, can be translucent enough to look natural. And if they are bonded to the teeth, instead of being cemented with conventional dental cement, they won’t show a black line at the gumline.
- The CEREC crown – CEREC is are also milled from a block of very hard ceramic material. What’s unique about CEREC is that the crown is milled by a computer in the dentist’s office rather than in a separate dental laboratory. Thus, the dentist doesn’t have to send out for it to be made—it can be made on the spot. So, no second appointment is required, and no wearing of a temporary crown between appointments. CEREC is milled from a block of ceramic that is a single color, so it is generally not considered esthetic enough for demanding cosmetic dentists. A few exceptional dentists who are artists, however, are able to custom stain Cerec for front teeth so that they are truly beautiful. Some even make CEREC veneers that can be placed the same day. To be precise, CEREC is actually a technique and not a material. There are several companies that make ceramic materials for use in CEREC machines.
- The e.max crown – e.max has become a very popular type of crown with cosmetic dentists, and I have a couple of them in my mouth. It is made out of lithium disilicate, an extremely strong ceramic. It can be cast, similar to the Empress crown, or it can be milled in a CEREC machine. In highly esthetic situations, the crown is first cast or milled, and then the front part is ground away and re-built using techniques similar to the way traditional feldspathic crowns are built up and fired.
- The InCeram crown – InCeram is made of a very dense and very tough aluminous porcelain. It also has excellent esthetics, but is more opaque than feldspathic porcelain. InCeram is also strong enough to be cemented with traditional dental cement.
- There are other types of all-ceramic crowns. We’re not going to list all of them here.
ADVANTAGES AND DISADVANTAGES OF ALL-PORCELAIN AND ALL-CERAMIC CROWNS
Let’s compare all-porcelain with porcelain fused to metal.
- All-porcelain is generally not as strong as porcelain fused to metal. It has to be bonded to the tooth in order to have adequate strength for oral function. The bonding technique is very demanding and is not fully taught in dental schools. We recommend that you only have an expert cosmetic dentist place this type of crown.
- With porcelain fused to metal, the porcelain has to be opaque in order to block out the appearance of the metal underneath. They all also eventually develop an unsightly dark line at the margin where the edge of the crown meets the tooth.
- Some of the all-ceramic systems that have an inner ceramic core with an outer layer of porcelain baked on require more tooth reduction. Grinding away more of the tooth is often not desirable.
- Some of the ceramic materials that are very tough and fracture resistant are also quite abrasive against the opposing teeth. Of the crowns listed above, the Empress is the kindest to the teeth it chews against.
GENERAL RECOMMENDATIONS FOR ALL-CERAMIC CROWNS
- There are several factors that need to go into the selection of a crown material: strength requirements, esthetic requirements, the abrasivity of the material against the opposing teeth, and the skills of the dentist. There is not a single crown that is clearly superior for all situations. Many cosmetic dentists will have several types that they will use, each for a different situation.
- It is generally a poor idea for a patient to go to a dentist and request a specific type of all-porcelain or all-ceramic. We have received many e-mails from patients who have done this and have been very disappointed with the results, because they were pushing their dentist to use a material the dentist was not comfortable with, and many dentists will try very hard to conceal from patients any discomfort they feel with a procedure. Each of these crown types requires a different preparation technique and has other quirks, and a dentist needs to have specific training with that crown to use it properly. There is also the factor of the dental ceramist, whom you will most likely never meet. The material that is used for the crown should be intimately familiar both to the dentist and to the ceramist for the best results. Knowing as much as I do about the different crowns, I have always let the dentist working on me choose the material he wanted for the crown. When I have had a special request, I have gone to a dentist I knew was proficient in that technique.
- You cannot learn, as a patient doing online research, which crown is best. First of all, there simply isn’t one all-ceramic material that is always best. Second, in a web page such as this, we can’t list all the properties of all them. Third, in evaluating these crowns, there is a great deal of background information needed in order to evaluate which research claims are fully established and which claims should be questioned.
- My recommendation, at mynewsmile.com, is that you find a cosmetic dentist you can trust and that understands your needs and is passionate about creating beautiful dentistry. Then ask that expert cosmetic dentist to use the technique that he or she is most comfortable with in creating the all-ceramic crown that will be best for you. The choice of the material is secondary to the skills of the dentist and of the ceramist in working with that particular material. There are subtleties in working with all of these all-porcelain and all-ceramic materials that need to be mastered by the dentist and the ceramist to produce the most beautiful result.
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