Composite vs. porcelain veneers. - Advantages / Disadvantages
A) A porcelain veneer may look more natural.
Porcelain has a glass-like translucency that closely mimics the light handling characteristics of tooth enamel.
In comparison dental composite (the restorative used with bonding technique) is more opaque and therefore typically can't mimic the luster of tooth enamel as well.
One of the properties of tooth enamel is that it is translucent. When light strikes a tooth it penetrates on into and through its enamel layer. It then reflects off the tooth layer below (dentin) and back out of the tooth.
It's this phenomenon that gives a tooth its luster. It's also what gives a tooth its color. A tooth's shade is a function of the combined effect of the color of the tooth's enamel as well as its dentin (the layer that the light has been reflected off of).
How porcelain veneers handle light.
Just like tooth enamel, porcelain veneers are translucent. However, when light passes into a veneer it's reflected back out when it hits the cement that's been used to bond it in place.
That means the tooth's final appearance will due to a combination of the luster created by its veneer's translucency, the veneer's color and the color of its underlying cement.
How dental bonding handles light.
Dental composite is typically much more opaque than either tooth enamel or porcelain. And as a result, the light handling characteristics of veneers made from it are quite different.
For the most part, light that strikes a composite veneer is reflected off its front surface. This lack of translucency means little natural-looking luster is generated. As for tooth color, it's simply a function of the color of composite that's been used.
B) Porcelain veneers will resist staining better.
Since porcelain is a ceramic (an impervious glass-like substance) a porcelain veneer will resist staining extremely well. In comparison, the material lying at the core of tooth bonding (dental composite) is a plastic and this plastic can (and usually will) discolor over time.
There is one aspect of a porcelain veneer that isn't so stain resistant and that is the cement that has been used to bond the veneer into place. This cement layer lies sandwiched in between the veneer and the tooth. The portion of this cement layer that is exposed around the edges of the porcelain veneer has the potential to accumulate stain over time.
Dentists usually try to hide the edges of porcelain veneers so they do not show when a person smiles, but if an edge is visible (or possibly becomes visible due to gum recession) this cement layer will be visible too. If pronounced discoloration of the cement has occurred, then the cosmetic appearance of the veneer will be spoiled.
C) Porcelain veneers are strong but brittle.
It is the nature of porcelain that it can be brittle. If a porcelain veneer is used in an application where it is subject to excessive forces (like in the mouth of a person who grinds their teeth) the veneer will be prone to fracture. If a porcelain veneer does break it cannot be repaired, instead it must be remade.
D) Placing porcelain veneers takes more dental appointments.
It will take a dentist two appointments, typically scheduled some days or weeks apart, to place a porcelain veneer. In comparison when a dentist uses cosmetic tooth bonding to create a composite veneer only one appointment is needed.
Advantages and disadvantages of composite veneers.
Creating veneers out of dental bonding is a technique that has been around since the 1960's. As years and decades have passed the manufacturers of dental composite (the restorative used with tooth bonding technique) have greatly improved its characteristics, both functional and esthetic. Without question in the hands of a skillful dentist dental composite can be used to create beautiful and natural looking veneers.
A) Composite veneers usually cost less.
Cosmetic dental bonding will usually cost less than a porcelain veneer. Dental composite veneers are placed in just one visit whereas porcelain veneers require two appointments (and therefore likely more of the dentist's time). When making porcelain veneers a dentist will incur a bill from the laboratory technician who has made the veneer, whereas with tooth bonding it is the dentist who creates the veneer.
B) Dental composite veneers can be repaired if they break.
Unlike porcelain, if a veneer created from dental bonding does chip or break a dentist can usually repair it. And in most cases they can probably make the repair by just patching the broken part, as opposed to replacing the entire thing.
Although repair is easier with composite veneers, their need for maintenance often is greater than with porcelain ones.
Dental composite is a plastic. And although manufactures do add components to enhance wear resistance, it still occurs.
A person may notice that over time the outline shape of their composite veneer has changed (especially on its biting edge). In comparison, porcelain is harder, and therefore will hold its original outline form better over the long term.
C) Bonding usually stains over time.
Composite veneers have a tendency to stain. The entire veneer may become discolored or else just portions of it. Staining is often associated with the use of coffee, tea, cola, and tobacco products.
It might be possible that just polishing the surface of the bonding will reinstate it to its original appearance. In other cases, the dentist may feel they need to reduce the entire face of the veneer and then resurface it with a new layer of tooth bonding.