For people seeking a cosmetic smile makeover, porcelain veneers are one of the most successful and comprehensive treatments available. Porcelain veneers are thin facings of porcelain that are bonded to the front of teeth. They are a relatively expensive treatment for cracked, chipped, stained, or misaligned front teeth, but if you consider that they can correct all these conditions simultaneously, they can become a cost-effective solution for people seeking correction of all these dental problems. Cosmetic dentists push porcelain veneers because they are a high-ticket item, and in promoting them, doctors make them look very good. But are porcelain veneers really as good as advertised?
Understanding the Porcelain Veneer Process
When you go to a cosmetic dentist to have porcelain veneers installed, the tooth is first prepared by removing some enamel to allow the veneers to fit onto the teeth. Then an impression of the prepared teeth is made. This impression is used to custom-craft porcelain veneers at a dental restoration laboratory. Although many dental restorations have benefitted from the invention of CEREC technology, which can craft the restorations while you wait, veneers are made and used in too large a set for the CEREC process to be practical. The laboratory fabrication process can take two weeks or more. Once the finished veneers return, they are checked for color and fit, then bonded to your teeth.
Significant Tooth Enamel Loss?
Some people are concerned about the loss of tooth enamel incurred during preparation. Dentists try to remove between 0.3-0.5 mm, although studies have shown that the same dentist using the same preparation method can remove very different amounts of enamel. Even depth guides, such as horizontal or vertical orientation grooves or bur indentations, do not counteract this variation. The amount of enamel removed is significant, because studies have shown that the thickness of tooth enamel ranges from 0.31 mm 1mm above the cemento-enamel juncture--the place where the tooth changes into the root—to 0.75 mm at 5mm above the juncture, and decreases with age, meaning that many people will have all or nearly all their enamel removed during the preparation for porcelain veneer placement. Studies have shown that this is a definite concern. Ideally, the porcelain veneer will protect the tooth in lieu of your enamel. That is, if the veneers have a reasonable lifespan and do not promote decay.
Lifespan of Veneers
6-month and 3-year studies have shown that the retention rate of porcelain veneers was between 91-100%, which sounds good, but out of 100 people receiving 8 veneers each, you would expect that as many as 72 of them would lose at least one veneer. More recent studies tend to report higher retention rates, reflecting the continual improvement of materials and techniques . One recent study reported a retention rate of 100 %, although it did report a chipping rate of 6 %.
Decay around Veneers
Porcelain veneers are generally reputed to strengthen and protect teeth. Because they are custom-fitted to teeth and bonded using a composite polymer, they do not offer harborages for bacteria along their margins, the way that might be expected of metal amalgam filling . As a result, decay of teeth around the veneers is not generally experienced.
From Whose Bourn No Traveler Returns
Looking at these factors, there are some reasons to be concerned about porcelain veneers. However, on the whole they represent reliable restorations with a long lifespan and protective capacity. One important disadvantage, though, is that the preparation marks teeth forever, especially if your enamel is completely removed, revealing the dentin. If a veneer is lost, the etched tooth surface will be highly visible and the veneer must be replaced quickly. Fortunately, since the veneer is relatively long-lived, it is not normally the veneer that fails first, but the bonding, so the veneer can be simply bonded back in place if necessary.
