Placing porcelain veneers - The procedure.
This page outlines the individual steps a dentist follows when they make and place a porcelain veneer. Although we only illustrate this process for a single tooth, several teeth can be treated simultaneously, as a group.
Step 1: Trimming the tooth.
With porcelain veneers, the idea is that the front side of the tooth is trimmed back about the same thickness as the veneer that will be placed. That way the thickness of the tooth is not dramatically changed.
Other than that, there are few set requirements. If your tooth has some small areas of decay, your dentist will trim more extensively in those regions so it is removed.
They'll also design a shape where the edges of the veneer will be positioned just out of sight.
Exactly how much is trimmed away?
The precise amount of tooth enamel that's shaved off will vary with each case. But with most, it's on the order of .5 to .7 millimeters.
That's about twice the thickness of an eggshell. And compared to most other dental procedures, it's an extremely small amount.
In fact, it's so little that with many cases dental anesthetic ("Novocain") will not be needed.
Step 2: Taking the shade.
Your dentist will need to use their shade guide and determine which color of porcelain most closely matches the teeth that lie to each side of the tooth they're working on.
They may decide that different portions of the veneer need to be different colors. They'll also make notes about which regions need to be comparatively more or less translucent.
Step 3: Taking the impression.
Once the trimming has been completed, your dentist will need to take an impression of your tooth and its surrounding teeth and gums. It's this copy of your mouth that will be used to fabricate your veneer.
There are two ways an impression can be taken.
Option A - Most dentists will take an impression using "impression putty."
This is simply a thick paste that's loaded into a tray and then squished over your teeth. It's allowed to sit for a few minutes until it's set and then the completed impression is removed from your mouth (see picture).
This impression is then sent to a dental laboratory and they will use it to make your porcelain veneer. Depending on what arrangements have been made, the turn-around time for this process is usually about 2 weeks.
Option B - Your dentist may have a dental milling machine that's coupled with a camera that can take an impression of your tooth optically.
Using this image, the machine can then grind your veneer out of a block of ceramic (a synthetic porcelain), in a matter of some minutes.
The obvious advantage of this technique is that your tooth can be trimmed and its veneer bonded in place, all in one visit.
As convenient as this sounds, if your dentist doesn't have one of these machines it can be for good reason.
1) Milled veneers are ground out of a block of uniformly-colored ceramic.
2) In comparison, veneers crafted by a laboratory technician can be characterized. Layers of porcelain, each having a different color and degree of translucency, can be use to create a veneer that truly mimics the unique characteristics of the neighboring teeth.
Step 4: Placing a temporary veneer (if needed).
In those cases where your veneer will be fabricated by a dental laboratory, you will usually have to wait 1 or 2 weeks while it is being made. The question then becomes whether or not you will wear a temporary veneer during this time period.
A) Situations where no temporary is placed.
This is the usual plan for cases where just a minimal amount of tooth structure has been removed (like in our picture above). Admittedly, on close inspection your tooth will look a little strange. But how much of a concern this is, is simply up to you.
Since a surface layer of your tooth has been trimmed off, you may notice that it has an increase sensitivity to hot and cold foods and beverages. You can also expect that it will feel a little rough to your tongue and lips.
B) Situations where a temporary is used.
It's more common to place a temporary veneer when treating cases where there's been a need to trim a relatively greater amount of tooth structure. These are teeth whose appearance would be noticeably strange, or where the issue of thermal sensitivity might be a problem for the patient.
If having a temporary placed is important to you, and your dentist has not yet discussed this issue with you, you absolutely need to ask about it when your appointment is scheduled.
Step 5: The pre-cementation evaluation.
(At this point, your veneer has been fabricated and is ready to be bonded onto its tooth. If a temporary veneer has been placed, your dentist will remove it.)
A) Checking the fit.
Your dentist will first need to evaluate how your veneer seats on your tooth.
To do so, they'll set it in place, inspect it, remove it and trim it, repeatedly, until they are satisfied with its fit. (In most cases, an anesthetic will not be needed during this step or any of those that follow.)
B) Evaluating the shape.
Even though the laboratory or milling machine that has made your veneer has crafted it to what it thought was the ideal shape, you and your dentist may decide differently.
Possibly certain edges need to be shortened, squared off or rounded so it looks right. If so, your dentist will complete these changes. And if needed, further refinement can be made after the veneer has been cemented.
C) Evaluating the color.
Your dentist will have chosen that shade of porcelain that most closely matches its neighboring teeth. But because a veneer is translucent, its precise color can be fine tuned by the shade of the cement that's used to bond it in place.
Your dentist will choose cement that they feel will provide the best color match. And then place some of that cement's corresponding "trial paste" into the veneer. (Trial pastes have the same color properties as their corresponding cement but don't create a bond with the tooth. They're just for testing purposes.)
The veneer can now be placed on your tooth so you and your dentist can evaluate how its color will look. If it's not a good match, your dentist can repeat this same evaluation using other shades of trial pastes, until the right color cement is found.
Step 6: Bonding the veneer.
Once you and your dentist have determined that its shape and shade are right, your veneer can be bonded into place.
Your dentist will first clean and prepare your veneer's internal surface. They'll also polish your tooth, so it's good and clean.
They'll then etch the surface of your tooth with an acidic etching gel (the green in our illustration) for about 15 or 20 seconds. (At a microscopic level, this etching process creates a very rough tooth surface. It's this texture that the veneer's cement bonds to.)
After washing the etching gel off and drying your tooth, a layer of clear "bonding agent" is applied. (This creates the actual bond to the tooth's etched enamel surface.)
Cement (having the color previously chosen) is then placed inside the veneer and it is gently squished into place.
Once everything is positioned properly, your dentist will set the cement by way of shining a "curing" light on your tooth.
This light (which has a blue color) passes through the translucent veneer to reach the bonding agent and cement which lies underneath. The light activates a catalyst in these materials, causing them to set in about a minute.
The veneer is now securely attached to your tooth.
There will be some excess cement that needs to be trimmed off. And you and your dentist will need to evaluate your veneer's contours and trim and polish them as is needed.
As a last step, your dentist will evaluate your bite and confirm that it is not altered by your new veneer.
Step 6: The follow-up appointment.
Most dentists will want you to return to their office in about one week.
They'll want to evaluate how your gums have responded to the presence of your new veneer. And if you have decided that its shape needs to be adjusted some more, they can do that at this appointment too.
Some people may notice that their veneered tooth as some hot and cold sensitivity. If you do, let your dentist know during this visit. While it's common that it will resolve on its own, they may be able to speed the process up.