In this monthly feature, Dr. Gordon Christensen addresses the most frequently asked questions from Dental Economics® readers. If you would like to submit a question to Dr. Christensen, please send an e-mail to [email protected].
When making temporary restorations for ceramic veneers, I find that the temporaries are very difficult to retain in place during the time they are needed. What can I do to make the restorations stay in place better between the tooth-preparation appointment and the seating appointment?
Answer from Dr. Christensen ...
I agree that this seemingly simple task is one that often fails, resulting in disgruntled patients and occasionally sensitive teeth. When provisional restorations are needed for veneers, I suggest the following procedure for making and seating resin provisional restorations:
➤ During an appointment before the tooth-preparation appointment, make a diagnostic cast of the teeth to be treated with veneers.
➤ Let the cast dry thoroughly.
➤ Place a layer of any unfilled bonding agent on the teeth to be prepared.
➤Find some resin-based composite that you are not using. Each of us has some boxes of old light-cured resin restorative material that we are not using. Check to make sure it still cures adequately.
➤ Using your gloved fingers, mold a small piece of the composite resin on the facial surface of each tooth to be prepared. Place the resin on the cast surface over the cured layer of bonding agent, and shape it to simulate a veneer slightly thicker than you plan for the final restoration. This extra thickness allows some bulk of provisional material for final finishing and polishing.
➤ Cure the resin.
➤ Make a “suck-down” shell over the cast.
➤ Cut the shell to include only the teeth to be prepared, plus a few teeth on each side of the teeth to be veneered. You now are ready for the tooth-preparation appointment.
➤ Prepare the teeth in the mouth.
➤ Place an appropriate amount of bis-acryl resin in the shell adequate enough to provide ample material for the temporary veneers. Example materials include Protemp™ 3, Integrity™,Luxatemp®, and many similar products.
➤ Seat the bis-acryl resin-filled shell into the mouth.
➤ Allow the resin to cure.
➤ Remove the shell and the cured resin from the mouth. Assuming the veneers are on contiguous teeth, the provisional veneers are connected.
➤ Roughly finish the provisional restorations, keeping them attached.
➤ Using phosphoric acid gel, etch a small (2 to 3 mm) circular area on the facial enamel surface of each prepared tooth.
➤ Seat the provisionals with the same resin cement that you are going to use for the final restorations or with a resin-provisional cement such as TempBond® Clear by Caulk.
➤ Slightly cure the resin cement, but do not cure it completely. Pick off the extra cement around the periphery of the provisional restorations.
➤ Complete the cure of the resin cement.
➤Advise patients that the provisional restorations do not resemble the final restorations in appearance, and that they should take great care to chew lightly on them.
➤ Place the final restorations as soon as possible.
The previously described technique will provide veneer-provisional restorations that have both relatively acceptable esthetics and strength. With patient cooperation, they will survive through the provisional restoration period. It is well-known that provisional restorations for veneers usually are much weaker than provisional restorations for crowns.
Our newest video, V1512 “Veneers, the Most Beautiful of Restorations,” is the best ceramic-veneer video PCC has produced. It shows the complete veneer procedure, including the making of provisional restorations. For information on this and other PCC educational offerings, call (800) 223-6569 or visit PCC’s Web site at www.pccdental.com.
Some new resin sealers have recently been introduced for placement over both temporary and final restoration surfaces and for other uses. Are these sealing products any different from the long-present FORTIFY™from Bisco or PermaSeal® from Ultradent Products?
Answer from Dr. Christensen ...
Sealing products - not to be confused with sealants - have been on the market for many years. They have been suggested for smoothing surfaces and sealing margins of resin-based composites, glass ionomer restorations, resin provisional restorations, demineralized areas on teeth, or other uses.
One of the major reasons for using sealers has been to fill in around resin-based, composite restoration margins, expected to be microscopically open due to the polymerization shrinkage of restorative resin during curing. Some companies suggest using sealers to provide a new smooth surface on continually roughening, microhybrid resin-based composite restorations. Many dentists have used the sealers you mentioned with apparent success. With some exceptions, the real value of the materials has not been immediately visible clinically. But research has supported their use and intermediate longevity value. A challenge with older sealers has been their oxygen inhibition. When using older materials, a layer was placed on a specific site, and was clearly visible before curing. However, because of the layer’s thinness and the relatively thick polymerization inhibition of the sealer resin, it was impossible to approximate or predict the actual cured thickness remaining on the restoration or tooth.
Recently, new sealer products have been introduced that have no oxygen inhibition. Examples include BisCover™ from Bisco and DuraFinish™ from Parkell. It now is possible to place a layer of these sealers with a suitable small instrument, visually estimate if the thickness is acceptable, cure it, and have the same thickness after curing that was observable previously. Although this may seem like a small reason for changing to another product, dentists report there is additional value in knowing what amount of the resin will cure. The new sealers will not cure with some LED curing lights. In summary, yes, the new sealers provide advantages compared to the original sealers.
Dr. Christensen is a practicing prosthodontist in Provo, Utah. He is the founder and director of Practical Clinical Courses, an international continuing-education organization for dental professionals initiated in 1981. Dr. Christensen is a co-founder (with his wife, Rella) and senior consultant of Clinical Research Associates which, since 1976, has conducted research in all areas of dentistry and publishes its findings to the dental profession in the well-known “CRA Newsletter.” He is an adjunct professor at Brigham Young University and the University of Utah. Dr. Christensen has educational videos and hands-on courses on the above topics available through Practical Clinical Courses. Call him at (800) 223-6569 or (801) 226-6569.