Answers to Tough Questions By: David Hornbrook, DDS, FAACD

Dear David,
An upper second bicuspid, a virgin tooth, has a crack across it from mesial to distal. It does not look like it has extended through the dentin, but the tooth is very sensitive when she bites down on an orangewood stick. She claims that she bit into something at a restaurant and her statement to me was, “It does not feel good when I bite.” It is not spontaneously sensitive, nor does the pain linger after the stimuli is removed. Do I need to do a full coverage restoration, or would an MOD Resin or ceramic inlay take care of the concern?
R.S., Milwaukee, OR

Dear R.S.,
The determination for what type of restoration needs to be placed really depends upon the amount of missing tooth structure and/or the desire for improved aesthetics. Since it sounds like a reversible situation, rather than reversible pulpitis, a restoration that will decrease the flexing of the dentin during function will probably alleviate the problem. If the enamel is fractured, the patient feels discomfort when she bites down due to pressure changes within the dentinal tubules. In the past, we would place this tooth into the category of “cracked-tooth syndrome” and place a full crown to eliminate flexing. I, however, would definitely recommend an intra-coronal restoration. Many studies have shown (One relatively recent, “Fracture resistance of endodontically treated premolars adhesively restored”, Ausiello, et al., American Journal of Dentistry) that a bonded restoration will restore a tooth back to it’s virgin strength. In fact, the standard deviation is actually lowered with a bonded restoration, indicating that it may help eliminate propagation of existing fractures. With this in mind, keep it conservative. A resin inlay is an excellent restoration in this example. Some of the leading materials include Symphony, Targis, and BelleGlass. I have placed hundreds of bonded restorations in teeth that elicited the classic “Cracked Tooth Syndrome”: no apparent problems other than the inability to bite down on it. They have been extremely successful and will continue to be my treatment of choice.

Dear David,
I recently bonded in a six-unit veneer case and I thought I did everything right, but the final result showed a severe cant in the smile—it leans to the left. I used your idea of a bite registration with a stick to line up with the intra-pupillary line, but I must have goofed. I have not taken your advanced course at PAC~Live yet, but can I save the case with some creative post-cementation recontouring or do I need to replace the centrals or the whole case.
Help!
K.Y., California

Dear K.Y.,
Well, the advanced course at PAC~Live will definitely help since post-operative recontouring is something we cover in detail. You certainly know how much of an effect just mild post-cementation recontouring can influence the final esthetic result after seeing all the things we did at the Functional Anterior PAC~live course. About your particular case, it really depends upon the degree of the cant. Usually, other than a very slight cant of the centrals, the case needs to be redone, because as you reduce the incisal edge, you will be removing all the translucent incisal that you worked so hard to communicate to the lab in the first place. This is really a problem if you just try to shorten one side. Another problem with a cant is that usually the midline between the centrals is perpendicular to the incisal edge, so now the midline does not bisect the face, but rather cants as well. If this is mild, creative contouring and alteration of line angles is a possible remedy, but not very often without compromising the case. Usually the cases I see that are recontoured severely are major compromises. Remember that your patient sought you out and had treatment rendered because they thought you would produce the best result you are capable. Any compromise just to save time or another lab bill is unfair to the patient. I would use this cant as another communication tool for the lab so that this won’t happen again. I would go ahead and shorten one side or add a flowable composite to the other side and try to reestablish a new incisal edge that is parallel to the intra-pupillary line. Take an impression of this new incisal edge and send it to the lab and tell them to match this incisal position. I know this is not what you want to hear and it would be easier to ignore it or tell the patient it doesn’t look that bad, but this can actually be a positive thing for your practice rather than a negative one. You can explain to your patient that, “Yes it is an inconvenience and you are truly sorry, but you are unwilling to settle for anything but the very best for them. Other dentists may be satisfied with the results, but you’re not, and quite frankly you are unwilling to let the patient have a smile that is less than the very best.” You would be surprised how many times the patient will say “Thank you, I knew I made the right decision when I chose this office.” Good luck.

Dear David,
What do you think of the Procera system? I have a situation where the patient requests no metal and there are deep subgingival margins. Would you use resin ionomer cement or do I need resin cement? Thank you.
E.A., CA

Dear E.A.,
I am very excited about the results I am getting with Procera. It’s use in North America has really increased the past few years due to the overwhelming success and Nobel Biocare, the manufacturer, has just introduced a bridge material that will allow us to eliminate the need for metal in many of our “missing teeth” scenarios. Applications for Procera, as far as I am concerned are for those situations where a full coverage crown is to be placed, either due to amount of tooth present or if there was a pre-existing crown, and isolation with a rubber dam could not be achieved. Subgingival margins are not a contraindication for a bonded restoration such as resin or pressed ceramic (i.e. Empress), but the inability to isolate definitely is. Usually I find myself placing a Procera on a second molar where I removed a full coverage crown that had subgingival margins. The difficulty in utilization of a rubber dam due to not finding an anchor for the rubber dam clamp eliminates a bonded restoration.

As far as cements, the jury is still out regarding resinionomer cements, such as RelyX LC (3M). Clinical trials using early resin ionomer cements, such as Advance (Dentistry) with In-Ceram (Vident) crowns, showed high fracture rates due to the expansion of the cements with water absorption. Even Dentsply acknowledges the problems and have since replaced it with a very good material, Principle. RelyX LC, which used to be named Vitremer LC, however, has not shown the same response, and I feel that it could be used for Procera. The cement of preference, however, would be Panavia (Kuraray America) due to increased bond strength, decreased water solubility, and some retention to the Procera, but it is more difficult to remove the excess. I currently am cementing every other Procera with RelyX LC and monitoring the results. So far, zero failures, but then again, I have been only using Procera for three years.

Dear David,
Are you using Targis/Vectris only for an anterior resin-bonded bridge or are you veneering over the pontic with porcelain? Is it better for the lab to prep the pontic, make the veneer and then return it in two pieces?
D.G., TX

Dear D.G.,
The use of Targis/Vectris for the framework of an anterior resin-bonded bridge had proven to be very promising. We have utilized the technique of a resin framework overlaid with a ceramic veneer for almost 10 years, with very good results. Vectris, with it’s high flexural strength just makes this technique that much better. Most of the time I will place a ceramic veneer over the pontic. Although Targis has excellent esthetics, it is not Empress, and I have no idea how esthetic it will be five, 10, 15 years down the road. The way I treat this case is that after I prepare the abutments on the lingual, I take my impression and send a lab prescription asking for a Targis/Vectris bridge. I do color mapping, send photos, and discuss pontic design and contour. I don’t even tell the lab that I may veneer over it. When I get it back and cement it, I evaluate esthetics to determine if a veneer is even necessary. About 25-30% of the time, the esthetics are so good that I don’t need to veneer the pontic. The other 70-75%, I know better esthetics could be achieved with a veneer. If I need a veneer, I prep it at this framework seat appointment. The advantage of me preparing the pontic rather than the lab is that I now have better control over tissue height, in case I need to modify it, interproximal margin placement, and it is much easier to place a veneer over an already cemented pontic than try to seat them together. If I let the lab preps the pontic for the veneer, they are really just guessing where the tissue interproximally is and I may find visible margins that show from the facial. This second visit also allows me the opportunity to discuss other treatment options, such as veneering the adjacent or contra lateral teeth. After I prepare the pontic, I impress, and temporize using a direct composite. The third visit is then cementing the veneer. So to re-cap:

First visit: Prep. For framework, impress, temporize

Second visit: Seat framework, prep veneer on pontic, impress, temporize

Third visit: Seat veneer

Dear David,
I saw you use a laser to alter soft tissue and also prepare an ovate pontic site. It was incredible! Which laser is it and who makes it?
S.S., San Francisco, CA

The laser I am using is a DIODE laser from ADT . You are right in saying it is incredible. This is one instrument that I could not and would not live without. I use it probably in 95% of all my anterior cases, and now my hygienist is using it as part of her soft tissue management with excellent results. The amazing thing about it is precision, zero bleeding, and the lack of post-operative discomfort. For hygiene, we are actually seeing bone regrowth in deep pockets. The hygiene program at PAC~live has really taken off with their training of the hygienists in this new exciting area of lasers. The hygiene benefits are worth the investment. I feel so strongly about the place this diode laser has in esthetic care that we use them extensively in all of our courses at PAC~Live.

Dr. David Hornbrook graduated from UCLA School of dentistry and currently practices at “Dentistry for the Quality Conscious” in La Mesa California. He has been a guest faculty member of the post-graduate programs in Cosmetic Dentistry at Baylor, Tufts, SUNY at Buffalo, UMKC, and the UCLA Center of Cosmetic Dentistry. He has consulted with numerous manufacturers in product development and refinement and is on the editorial board of Practical Periodontics & Aesthetic Dentistry, Signature, and is the past editor of the Journal of the American Academy of Cosmetic Dentistry. He is also the current clinical editor of Dental Practice Report, as well a member of the Esthetic Dentistry Research Group, which publishes REALITY and REALITY NOW. He is an accredited member and Fellow of the American Academy of Cosmetic Dentistry and is the Director of the Pacific Aesthetic Continuum which is an advanced education facility for practicing clinicians desiring to enhance their cosmetic dentistry practices. David is also the founder of the Pacific Academy of Esthetic Dentistry. He has lectured internationally on all facets of esthetic dentistry and has published articles in most of the leading dental journals.

Contact David Hornbrook at: Dentistry for the Quality Conscious 7777 Alvaredo Rd, Ste 210 La Mesa, CA 91941 (619) 463-7797 Fax: (619) 463-1351 E-mail: drdavid@connectnet.com