Porcelain veneers bonding technique
Final cementation of porcelain veneers can be a very exacting and often difficult procedure. The following step-by-step technique describes an orderly way to handle this procedure, and some helpful hints to make the cleanup much easier.
Isolate all preparations with a rubber dam (be careful to always keep preparations moist to prevent sensitivity) .
Coat all teeth with chlorhexidine soap, or any similar material, to remove bacteria. Lightly remove excess with gentle air or wipe with a gauze square.
Coat all preparation areas with 37% phosphoric acid. It is best for the assistant to follow with a brush to spread it evenly. After 10 to 15 seconds, rinse thoroughly with copious amounts of water. Although it is not mandatory, I have found that coating the teeth with Gluma (Heraeus Kulzer) or HurriSeal (Beutlich Pharmaceuticals) helps desensitize the teeth through their wetting and antibacterial action.
Coat with one-step bonding agent; in this case, I used Prime & Bond NT (DENTSPLY Caulk). Remove excess with an air syringe. Note: To be able to first bond the liquid you must use a bonding agent that is thin enough to not interfere with the fit of the veneers. Then bond for the appropriate amount of time. Your assistant or second assistant should have prepared the veneers with 9.6% hydrofluoric acid, silane, and bonding agent (do not light cure). Then cover these with a light-protective cover.
Have your assistant load the veneers evenly with base cement. In this case, I used Nexus clear (Kerr). Unless the veneers are very opaque, you will only need base, not catalyst.
Wipe away the excess cement with 2 X 2 gauze and brushes. Then place pieces of floss between each veneer. The assistant often will apply some bonding agent to a small area of the floss that will be interproximal to act as a lubricant that will aid in its placement.
Tack each veneer while keeping it firmly in position.
Clear away excess with sharp sickle scaler, then remove floss by pulling it incisally and lingually. If you pull the floss to the facial, there is the chance of moving the veneer
Finish bonding process with curing light, and finish veneers.
The method for cementation as described is similar to many other methods previously documented, however, in this case the addition of using the floss prior to tacking the veneers in place saves a great amount of time. If done properly it should be a rare necessity to have to saw contacts open because of accumulated cement.