The porcelain veneer procedure. (continued)

Step 4: The pre-cementation evaluation of the porcelain veneer.

Before your dentist can bond your new porcelain veneer into place they will need to evaluate how accurately it fits on your tooth.

To do so, they will position it on your tooth, inspect it, remove it to trim it, repeatedly, until they are satisfied with its fit.

In most cases anesthetic is not needed for this step or any of the other steps we describe on this page.

A) Evaluating the porcelain veneer's overall shape.

When your porcelain veneer is fabricated it will be made so it has the "ideal" shape. Even so, you and your dentist may come to the conclusion that certain aspects of the veneer need to be shortened, squared off, or rounded so to make the veneer's appearance even more pleasing.

It will be difficult for you and your dentist to determine that the shape of the porcelain veneer is exactly right. This is because the veneer has not been bonded to the tooth yet, so its exact final positioning on the tooth isn't known. At this stage your dentist will need to error on the side of leaving the porcelain veneer slightly oversized. Then after the veneer has been cemented into place it can be trimmed to precise proportions.

B) Evaluating the porcelain veneer's color.

Your dentist will have chosen the shade of the porcelain that was used to fabricate your porcelain veneer because they felt it came closest to matching the shade of your tooth's neighboring teeth. However, because porcelain veneers are translucent, the precise color a veneer will possess can be adjusted by changing the shade of the cement that is used to bond the veneer into place.

Your dentist will choose a cement that they feel will provide the best color match for the veneer as compared to its neighboring teeth.

Once a cement shade has been selected your dentist will place some of the cement's corresponding "trial paste" into the veneer. Trial pastes have the same color properties as their corresponding cement.

Once the trial paste has been placed into the veneer the veneer can be placed on its tooth so both you and your dentist can see how the shade of the cement will affect the veneer's overall coloration. If you do not feel that the color of the veneer is a good match with your other teeth your dentist can repeat this same type of evaluation using other shades trial pastes, until the right color of cement is found.

It is important for you to realize that you must be happy with the veneer's shade before your dentist proceeds with the cementation process. After a porcelain veneer has been bonded into place it cannot be removed.

Step 5: Bonding the porcelain veneer into place.

Once you and your dentist have determined that the shape and shade of your porcelain veneer are appropriate it can be bonded into place. First the porcelain veneer will be cleaned and prepared for the cementation process. Your tooth will also be cleaned, usually by polishing it with a rubber cup or brush.

The enamel surface of your tooth will be etched with an acidic etching gel (the green in our illustration). At a microscopic level this etching process creates a very roughened texture on the surface of the enamel, just like glass that has been etched has a "frosted" texture. This surface roughness allows the cement to create a very strong bond with the tooth's surface, and it is a hallmark of dental bonding technique.

At this point cement will be placed into the porcelain veneer and the veneer will in turn be seated on your tooth. Once your dentist has ensured that the veneer is in its proper position they will cure the cement by way of shining a special light on your tooth. This light (which is usually blue in color) passes through the translucent veneer to the cement which lies underneath. The light activates a catalyst in the cement, causing it to cure in just a few moments.

At this point, the porcelain veneer is securely bonded into place on your tooth. There will probably be at least some excess cement present at the edges of the veneer that your dentist will need to trim off and polish down. You and your dentist will also need to evaluate the veneer's precise contours and trim or reshape them as you feel is needed. Your dentist will also spend time evaluating your bite and making sure that the veneer doesn't interfere with it.

Step 6: The porcelain veneer post-cementation appointment.

Most dentists will ask that you return to their office about one week after your porcelain veneer has been bonded into place. Your dentist will want to evaluate how your gums have responded to the presence of your new veneer. If you feel that the overall shape of your veneer needs to be adjusted, your dentist can perform that task during this appointment also.

Since that time when your porcelain veneer was bonded into place, you may have noticed that your tooth has some persistent hot and cold sensitivity. If you do let your dentist know during this follow-up visit. While it is possible that this thermal sensitivity will resolve on its own, your dentist may have some suggestions or solutions that can speed up the process.