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Letters to the Editor

April 30, 2013

Dear Dr. DiTolla,

Is BruxZir® Solid Zirconia (Glidewell Laboratories) indicated for inlays/onlays as well as crowns? I only hear it mentioned for crowns. For patients that insist on tooth-colored restorations on second molars, what do you place, if anything? I love IPS e.max® (Ivoclar Vivadent; Amherst, N.Y.), but I draw the line at the first molars forward.

– Jeffrey L. Schultz, DDS, FAGD
Bellaire, Texas

Dear Jeff,

BruxZir Solid Zirconia can be used for inlays and onlays, as well as crowns. We have dentists asking us for BruxZir veneers as well, which we can do, but I am waiting for some bond strength research to conclude before we make any recommendations. Veneers are essentially non-retentive preps, so we need to ensure that our cementation/bonding protocol is sufficient to retain them.

For tooth-colored restorations on second molars, BruxZir Solid Zirconia is the only choice. However, you need to have at least 0.5 mm of occlusal reduction. I have a 0.6 mm depth-cutting bur in my kit that I use for these restorations, and by the time I finish the reduction it will usually be at 0.7 mm. At 0.5 mm, you must reduce the opposing if the occlusion is high on the restoration; otherwise, the BruxZir restoration can fail. Cast gold still holds the title as the best second molar restoration, but you know as well as I do that most patients will not accept it.

Hope that helps!

– Mike


Dear Dr. DiTolla,

I’m totally blown away by “Chairside Live,” which I was intrigued to watch for the first time when you interviewed Gordon [Christensen] — I believe it was Part 3. First, let me congratulate you on the entire concept, which I found entertaining, informative and just plain fun to watch. You and Megan remind me of the old Dan Aykroyd-Jane Curtin SNL “Point/Counterpoint” parody. In any event, great job! I loved your retching skit at the end — hilarious!

But you know you and your guest can’t spew out data without skeptical Michael (that’s me) chiming in. As far as Gordon’s claim that various drinks such as lemonade are 10-times more damaging to the external stain on BruxZir zirconia than Coca-Cola, a quick search (Yahoo Answers, NEWTON Ask-a-Scientist) found that the pH of Coke is 2.5, while lemonade is 3.8. On the other hand, another site (21st Century Dental) lists Country Time Lemonade as having a pH of 2.5 and Coke Classic at 2.53. Gordon also mentioned energy drinks being worse than Coke, but this latter site found that Gatorade has a pH of 2.95. Bottom line: It’s very hard for me to believe that these drinks are worse than Coke when it comes to dissolving external ceramic stains, and 10-times worse? Nah! Even if pH is not the be-all and end-all factor, 10-times worse is still hard to believe.

You also stated that Multilink® Automix (Ivoclar Vivadent) was “self-etching,” but in fact, it’s the primers in the kit that are selfetching, not the cement itself. Minor point, perhaps, but your viewers could possibly have come away thinking that Multilink Automix is similar to RelyX™ Unicem (3M™ ESPE™; St. Paul, Minn.), which, of course, it’s not. In any event, you again came up with a terrific idea, which I have to admit I’m jealous I didn’t think of first!

– Michael Miller, DDS
Houston, Texas

Dear Michael,

Wow, coming from you that is quite an honor! I have such respect for what you do at REALITY (realityesthetics.com), and it means a lot when one of my mentors takes the time to write a letter like this. You might even see your letter read on “Chairside Live,” which would earn you a signed picture of Megan and me. I’ll be sure to mark it with a dotted line so you can cut me out of the picture. Plus, addressing your letter on the show will give me the chance to prove I know the difference between self-etching resin cements and self-adhesive resin cements.

Gordon was referring to an AGD study in their journal, General Dentistry (von Fraunhofer JA, Rogers MM. Effects of sports drinks and other beverages on dental enamel. Gen Dent. 2005 Jan-Feb; 53(1):28-31).

After that episode aired, a viewer sent me this link, http://fit4maui.com/water/pu/bottled_ph.html, which purports to measure the pH of different brands of bottled water. Could Aquafina and Dasani really have a pH of 4?

Thanks again for the kind words, Michael! They mean the world to me.

– Mike


Dear Dr. DiTolla,

I have followed some of your CE courses online. I see that you are a fan of SpeedCEM™ (Ivoclar Vivadent). Do you use SpeedCEM to cement feldspathic porcelain veneers? Would you etch with hydrofluoric acid if the lab has already done so?

– Marea White, DDS
Bedford, Texas

Dear Marea,

Nice to hear from you! I am a fan of SpeedCEM, which is a self-adhesive resin cement similar to RelyX Unicem or Maxcem Elite™ (Kerr Corp.; Orange, Calif.). While these cements are strong enough for inlays, retentive onlays and retentive crown preps, they are not strong enough to bond low-retention restorations such as veneers.

Every veneer manufacturer I have spoken with still recommends the total-etch (now called etch and rinse) technique for luting veneers, including higher strength veneers like IPS e.max.

There is one lecturer I know of, Dr. Jose Luis-Ruiz, who mentioned to me in an interview for Chairside® magazine that he is using self-etch to place veneers. However, he is doing it using a cement with a separate self-etch solution. PANAVIA™ F2.0 (Kuraray America; New York, N.Y.) and Multilink Automix are two good examples of self-etching resin cements with separate self-etch primers.

The standard of care today is to use the total-etch (etch and rinse) technique with a light-cured resin cement to place veneers.

The research I have seen does not show any improvement in bond strength if you re-etch the veneers with hydrofluoric acid in your office after try-in, although it is acceptable to clean the veneer with phosphoric acid.

– Mike


Dear Dr. DiTolla,

I practice general dentistry in Petaluma, Calif. A few months ago, I attended one of your CE courses through our local dental society, Redwood Empire Dental Society (REDS). I enjoyed your lecture and your sense of humor. Most importantly, I really liked all of your practical tips and information. I have been practicing since 2000, and have taken many CE classes, but your lecture has made the biggest impact on my practice so far. Your preparation and impression techniques have helped me achieve perfect impressions and my crown cement appointments are so enjoyable now. My dental lab technician had always told me that my preps and impressions were very good, but the small changes I made since attending your course have helped me achieve excellent and consistent results. I wanted to thank you and let you know how useful your tips have been to my practice and to me. I hope you return to this area to lecture again.

– Nadia Navid, DDS
Petaluma, Calif.

Dear Nadia,

Thank you so much for your kind letter. I love hearing stories like yours, and I know your lab techs will be thrilled with your preps and impressions as well. They will love you even more if you send a digital photograph with all anterior cases! I keep playing with new products and techniques, looking for ways to help dentists get better results in a simple, predictable fashion. I will be sure to pass any of those your way, and I hope I get a chance to make it back to your neck of the (red)woods soon!

– Mike