Porcelain crowns are used when a large portion of the tooth structure has been lost. The loss can be due to breakage, tooth decay, or a large filling has failed. Crowns without metal are preferred in the front of the mouth. The non-metal versions are beautiful and appear real. There many types of all-porcelain crowns. The different types are used in different situations depending on the patient’s needs.
All-porcelain crowns have many benefits
We prefer to use ceramic versions over those made with metal. The dark line at the gum line of crowns containing metal won’t develop. Ceramic restorations can be made thinner requiring less tooth reduction. They will not stain or change color. Ceramics are more bio-compatible than metal which may reduce gum recession.
Types of all-porcelain crowns | How are they made?
E Max – layered
E Max is the newest type of cosmetic material used for porcelain dental crowns. Like conventional PFM crowns, they are made with two layers. There is a strong and durable supporting layer called the coping. A lifelike top layer is applied on top of the coping by an ceramic artist to match the restoration to the natural teeth.
Emax is the preferred ceramic system for anterior teeth. It is both bio-compatible and has the long term wear pattern like that of enamel. Emax can be used for minimally prepared veneers or crowns as thin as 0.2mm. It makes beautiful restorations that are 2.5 to 3 times stronger than the other glass-ceramic systems used today.
E Max – Monolithic
E Max Monolithic is a one layer system using only the coping layer. The E Max coping is beautiful on its own. It does not use the weak top layer and is more resistant to chipping. It is the custom top layer of ceramic that is the weak link in all-porcelain systems. E Max monolithic is a good choice to create porcelain crowns suitable for nighttime bruxers or tooth grinders.
Zirconium crowns are considered to be the ultimate in strength. This ceramic is used to make one or two layer restorations.
The coping is extremely strong but is opaque and ugly. Two layer versions can be made to be attractive but are no stronger than E Max layered. The base coping is milled and has a weaker baked on top layer. This top layer is used to make the restoration attractive and lifelike. The thicker the top layer the less you see of the coping underneath. More drilling allows the veneer to mask the opaque bright white coping.
Empress can be made with the appearance of natural teeth. Due to lack of strength, Empress is losing popularity. This ceramic has two layers, a base coping made of medium-strength pressed ceramic, and a weaker baked on top layer. The top glass layer is hand stacked and fired onto the pressed base coping beneath. Blessed with only modest strength, Empress should never be used in grinders.
Feldspathic Porcelain Crowns
Many cosmetic dentists feel this is the most attractive porcelain. This custom stacked one layer ceramic is difficult to work with. The technician must have very high skills. Only high end dentists will use this ceramic system. Feldspathic choices cost more. These restorations are very technique sensitive to place and are much more costly to produce in the laboratory. These restorations have low to medium strength.
Cerec and Sirona | Trading Quality for Speed
Cerec and Sirona milling technology is growing in market share. The brand names Cerec and Sirona are “in the dental office” CAD milling machines.
Onlays or caps are milled from monolithic ceramic blocks. Monolithic means one layer and one color. No natural tooth is one color. These tooth shaped caps can be created in one visit. They are strong but they can only be customized by using surface stains. Surface staining is not life like. Surface stains wear off over time.
The popularity of these low priced milling machines is growing in average dental offices. There are three benefits that motivate dentists to use this inferior system. Cutting out the lab technician fees creates a financial incentive. The technology “appears” to be impressive to the patient. It trades quality for speed.
Are All-Porcelain Crowns Strong?
The strength is higher when a one layer porcelain system is used. Zirconium and E Max are the two strongest types of porcelain caps today. They are also the most popular. Zirconium is the strongest all-porcelain crown on the market at this time. When bonded properly to the tooth, both zirconium and E Max rival the strength of porcelain fused to metal crowns.
What do Porcelain Crowns Cost?
Dental crown costs vary with the time, expertise, and materials used. All three cost variables are determined by the quality level of the dental office and ceramist. Typically, a high end dentist will take more time, have better technique, and use better materials. They will work with a more expensive ceramist.
It is the ceramist who actually makes the restoration and charges the dentist directly for the service. Dental lab fees for a single cap will vary widely from $25-$2500. Obviously, so does the craftsmanship.
The total fee for a single all porcelain cap could be anywhere from $900 to $4500. Do not assume that the dentist charging $3000 is making any more money per crown than the dentist charging $2000. Dental insurance pays varying amounts but rarely more than $700 per tooth.
The quality levels of porcelain crowns varies tremendously
A better version will look more natural. It will have a better bite, be stronger, last longer, fit better, and will not fray or snap your floss. The gum tissue will be healthier. The tooth underneath will be less likely to decay or leak.
The old adage “you get what you pay for” very often applies. Most dentists are trained to do one tooth at a time. General dentists are not trained to do complex cases. The level of difficulty goes up when multiple teeth need caps at the same time.
Do your homework and get several opinions. Find a dentist that has the training and the experience. The dentist should do these procedures all of the time. They should have before and after photos of cosmetic dentistry to prove it.