What Happens to a Veneer over Time?

Most porcelain veneers nowadays are made from porcelain that is as strong as, or stronger, than your natural tooth.  The bonding agents we use are the best they've ever been.  That being said, the weakest part of any restoration is the cement bond where the restoration (veneer, crown, filling) and the tooth meet.  As that breaks down over time, the veneer or crown could debond and either fracture or fall off, although this is quite rare.  I would always choose to prepare for a veneer over a crown as there is so much more conservation of tooth structure with a veneer prep so when it needs to be replaced in the future, you will have more tooth structure to work with. 

Veneers are the strongest ceramic restoration that we as dentists can offer patients. In many instances, when porcelain is bonded to enamel, the strength of the tooth can actually increase! When considering veneers, it is important that your dentist makes sure that your bite protects the veneer against failure. This can happen if an opposing tooth hits the veneer "early" when chewing. If your bite is correctly adjusted, then the success rate of the veneer increases. If you're a grinder or a clencher, wearing a nightguard is an absolute necessity. Implementing a prescription-based high-strength fluoride toothpaste into your daily oral hygiene regimen will help prevent decay from forming near the veneer margin.

At some point, however, the veneer could fracture. Ceramic in the mouth is strong, but over time as our teeth are subjected to the normal stresses of chewing, a small fracture in the veneer can propagate to a large catastrophic fracture, and ultimately, failure ensues. I always use the analogy of breaking a paper clip when discussing failure of veneers to my patients: If you want to break a paper clip, you need to bend it back and forth several times until at some point, it fractures. This is because we are stressing the metal of the paper clip to a point where it can no longer handle the forces we are applying to it. Ultimately, the metal becomes too weak to resist these forces, which in turn causes it to fracture.

The veneer option is the best option we can provide--it is long-lasting, esthetic and durable. Good Luck!