Dear Dr. DiTolla,

I have been watching the free clinical videos on the Glidewell website and am impressed. Thank you for making these resources available at a price that’s hard to beat.

If you wouldn’t mind, could you answer a few questions? These questions focus on the video “Diagnosis & Placement of No-Prep Veneers”:

1) Would it be helpful to relate midsagittal and interpupillary planes to the lab, as in a Kois Dento-Facial Analyzer (Panadent; Colton, Calif.), or in your experience is this not necessary?

2) What brand of retractors were used (two types are shown)?

3) How do you deal with interproximal contact issues — hyper or hypo — at try-in, especially as there is no gingival margin to act as a stop?

4) How do you know when you need to use “shade-adjustable” porcelain?

– Vincent Johnson, DDS
Bay City, Mich.

Dear Vincent,

Thanks for writing and for the kind words! Here are some attempts at answering your questions:

1) It is very helpful to include that information; however, if you parallel the incisal edges of your preps to the interpupillary line, that is our default way of mounting the cast. That being said, it is much easier for us to do that if a Kois Dento-Facial Analyzer, or even a stick bite, is included.

2) The one I like best is the SeeMORE retractor from Discus Dental. There are rumors that they may stop selling that product, so I am looking into having it made here at the lab because we have an injection-molding machine on the premises.

3) The contact/seating issue is the worst thing about no-prep veneers. Sometimes I have the lab make a little finger of ceramic on the incisal edge of the veneer to prevent overseating, but then you have to grind that all away after bonding it into place. Really, it all comes down to “feel” and some educated guesswork. I hate procedures like that, but I haven’t found a better way yet.

4) You never have to ask for shade-adjustable ceramic anymore because it is now the material we use on all these types of cases, except for the ones where we are trying to block out a darker shade of tooth — something lower in value than an A3. In those cases, we either need to opaque the inside of the veneers or have the doctor prep the tooth so we can make the veneer a little thicker.

Since that video was produced, however, I now do nearly all my veneers in IPS e.max^® (Ivoclar Vivadent; Amherst, N.Y.). Because it is three times stronger than IPS Empress^® (Ivoclar Vivadent), I have yet to experience any of the incisal chipping or breakage that I did over the years with IPS Empress. In fact, IPS Empress is dying a slow death in our laboratory, while the number of IPS e.max veneers we do continues to grow. I foresee a time in the not-too-distant future when all veneers will be IPS e.max because of its optimum esthetics and strength.

Hope that helps!

– Mike

Dear Dr. DiTolla,

Just wanted to send you a note to say how much I enjoy reading your interviews in Chairside^® magazine. The two with Drs. Howard Farran and Paul Homoly are must-reads for all dentists. Sometimes I feel you read my mind with your questions. Keep up the good work.

– Steven Bellantese, DDS
Bronxville, N.Y.

Dear Steve,

Thank you for your kind words. I love long-form interviews, yet they seem to be such a rarity in dental magazines these days. I never feel like I learn anything from the one-pagers. It takes a few pages to ask follow-ups and give someone the space to answer.

– Mike

Dear Dr. DiTolla,

Thank you very much for the practically helpful educational support your lab provides to dentists. I wonder if you give written directions or drawings to the lab technician about the desired thickness of the wax-up design (in other words, how much dental tissue it is safe to prep). As a rule, technicians overprep teeth on the model, which leads to extra time to fit.

Cordially,

– Alex Zavyalov, DDS
New York, N.Y.

Dear Alex,

Yes, when I am having a diagnostic wax-up done, I will often send along one of my 0.6 mm depth cutters from my Reverse Preparation Set (Axis Dental; Coppell, Texas), and have the technician use it to place depth cuts. I let the technician know that is the most I want removed from the teeth to ensure that I stay in enamel.

– Mike

Dear Dr. DiTolla,

I really enjoy watching the educational videos you provide through the Glidewell website. Recently I have noticed an increased incidence of porcelain fracturing from the zirconia (Prismatik CZ™ and some NobelProcera™ [Nobel Biocare; Yorba Linda, Calif.]). I have started to use more BruxZir^® restorations in the posterior, but its limited esthetics are sometimes a problem. I fear I may have to return to PFMs. Any recommendations?

– Dr. Fred Curcio
Ridgefield Park, N.J.

Dear Fred,

Like you, I noticed a good deal of fracturing of porcelain-fused-to-zirconia restorations and have drifted to monolithic BruxZir Solid Zirconia. I find BruxZir restorations to be esthetically acceptable on first and second molars, especially when the patient’s other choice is cast gold! I am also very happy with the results I am getting with IPS e.max. So, basically, I usually go for IPS e.max in the anterior and BruxZir restorations in the posterior.

I haven’t done a single-unit PFM in two years, but I still use porcelain-fused- to-metal for many bridge cases where I don’t trust BruxZir as much — it’s still an all-ceramic product. Also, as you may have noticed, I am starting to put more anterior BruxZir cases on our website, but keep in mind these cases are being accomplished with the help of an in-office technician.

If you aren’t happy with the esthetics of BruxZir restorations, you may have to return to PFMs, unless you are convinced that IPS e.max is strong enough for the posterior. My personal feeling is that with 1.5 mm of occlusal reduction, IPS e.max is strong enough, but many dentists don’t give us that much reduction.

Hope that helps!

– Mike

Dear Dr. DiTolla,

I recently watched a video from Glidewell Laboratories where you were discussing the “cleaning” process for the internal surface of a zirconia crown (BruxZir crown, etc.) prior to cementation. You mentioned using Ivoclean^® (Ivoclar Vivadent; Amherst, N.Y.) and a zirconia primer. I will typically cement my zirconia crowns with the RMGI RelyX™ Luting Plus (3M™ ESPE™; St. Paul, Minn.). Would you recommend using Ivoclean and the zirconia primer prior to cementing with RelyX Luting Plus or only with resin-type cements (RelyX Unicem or RelyX Ultimate)?

Thanks so much for your help. I really enjoy your videos through the lab and find them all very helpful.

– Kevin G. Jones, DDS
Little Rock, Ark.

Dear Kevin,

It comes down to how retentive your prep is. If the prep is, say, 4 mm in vertical height and has no more than 10 degrees of taper, then cementing with a RMGI without the zirconia primer will work fine. As the prep gets shorter or more tapered, that is when you should consider using Ivoclean and Z-PRIME™ Plus (Bisco; Schaumburg, Ill.) in conjunction with an RMGI such as RelyX Luting Plus. When you need maximum retention, such as on a short mandibular second molar, you should probably go with Ivoclean, Z-PRIME Plus and a self-etching resin cement like RelyX Unicem. I now use Ceramir^® (Doxa Dental Inc.; Newport Beach, Calif.) as my everyday cement. One of its chief benefits is that it has a natural bond to BruxZir crowns, once the inside of the crown has been cleaned with Ivoclean. I also really like the way Ceramir cleans up, making it a very enjoyable cement to use.

Hope that helps!

– Mike