Adams Discusses All-Ceramics and More Ahead of Upcoming Seminar

Richard Gawel


With the rapid changes in today’s technology, dentists often feel left behind. A pair of seminars scheduled for Friday, November 10 at the Dental Future Center in Fort Washington, Pa, however, promises to help bring practitioners up to speed with today’s cutting edge tools and techniques. 

First, Dentistry Today Editor-in-Chief Damon C. Adams, DDS, will present “Trends, Hot Tips, & Innovations.” During his morning presentation, he will review current developments and controversies as well as practical clinical tips designed to help clinicians choose and successfully implement the latest lab-fabricated all-ceramic dental materials and treatment protocols.

In the afternoon session, Jon Julian, DDS, will discuss “The Power of Today’s Dental Technologies.” He will explore the full implementation of 3-D imaging, lasers, and platelet-rich fibrin into treatment plans to increase the level of care that dentists can provide. He also will touch upon how patients appreciate these technologies and say yes to treatment.  

Dr. Adams recently shared what attendees can expect to learn about all-ceramics from his session in our exclusive Q&A.

Q: Why have dentists and labs been moving increasingly to all-ceramic restorations? 

A: We have certainly witnessed tremendous growth in the use of all-ceramics over the past 2 decades. Recently, it was reported that the number of these restorations has eclipsed the total number of PFM and gold restorations currently being placed. And, the very rapid growth spike that started in about 2001 has been due to the introduction of high-strength polycrystalline ceramics, such as lithium disilicate and zirconia, which offer both layered and monolithic applications.

In vitro and in vivo studies published over the years have demonstrated increasing success rates with all-ceramic restorations. The manufacturers have given much time and effort to research and develop strong and increasingly aesthetic materials that can be fabricated with CAD/CAM fabrication processes that support more rapid production and higher profits. In addition, all-ceramics, including zirconia, are now a chairside option for same-day delivery. 

Q: Are there cases where all-ceramics are the best approach or simply inappropriate?

A: This is an interesting and important question! This is actually a topic that is, rather ironically, included in most of my lectures on all-ceramics. I entitled the section “All-ceramics: Always the Best Choice?” In this portion of my presentation, I make the case that there is still a place for “old-fashioned” gold and PFM restorations in certain patient case situations. Also, with the rapid and recent progress in the strength and reliability of a variety of composite resin materials, coupled with new and better delivery methods, there are often more minimally invasive approaches to tooth restoration that can and should be considered before automatically going to full-coverage preparations with all-ceramic restorations. 

In Dentistry Today, we have published case reports by distinguished clinicians and authors, such as Drs. Douglas Terry, David Clark, Hal Stewart, and others who demonstrate the use of direct composite resin injection/overmolding techniques used to restore teeth that would have previously been cut down for full-coverage restorations and then restored with all-ceramic materials. Diastemas, unsightly hypoplastic enamel, or black triangles in the anterior teeth, and so on can all be evaluated for more conservative preparation-free or nearly preparation-free restorations, depending upon the clinical circumstances and desires of the patient. 

Q: What are the biggest challenges in using all-ceramics?

A: Another large part of my lecture is this question about the challenges accompanying the use of all-ceramics as related to proper treatment planning, material selections, and preparation designs. My professional experience over the years as first a clinician, then as a dental laboratory consultant and doctor-technician liaison, and finally seeing dentistry from the perspectives gained as the editor-in-chief of Dentistry Today for the last 10 years, is that there is no cookbook approach to material selection. Many important factors come into play. Thus, in the arena of restorative dentistry, material selection is really the first major hurdle to overcome in the treatment planning of a case and for the successful use of modern all-ceramics. 

High-quality preparations are a must for the best aesthetic and long-term functional outcomes and, furthermore, the various material-dependent designs need to be clearly understood by the clinician. For example, preparation requirements, as seen with the recent changes for lithium disilicate restorations, have been changing after evidence was released that supports more minimally invasive prep designs. So, one can soon see that many decisions become material specific and patient specific, requiring a thorough treatment planning protocol that identifies the factors upon which the material choice decisions are made.

Q: When should monolithic applications be used? 

A: This is an excellent question that does not lend itself to a simple and short written explanation in this setting! Monolithic applications have been touted as the way to go, and, from a strength standpoint, this is certainly the biggest advantage of monolithic material applications; this is the case whether the material chosen is lithium disilicate, zirconia, or perhaps the newer zirconia and lithium silicate (ZLS) hybrid materials that were recently introduced. The most controversial topic that I present in my lectures is that doctors have been following marketing hype and putting certain materials or material applications in their patients’ mouths that are not yet fully backed up by long-term scientific and in vivo evidence. Such is the case with the huge rush away from more proven materials such as lithium disilicate to monolithic zirconia over time.

I go into the reasons that this “movement” has happened in my lectures and pose the question, “Are strength and resistance to fracture the only issues that matter?” Are there going to be other, more significant reasons for restorative failures in the future than, say, fractures/breakage of restorative materials? What in our restorative materials history might support the legitimacy for even asking this question? In fact, I present a very solid case, using evidence available in case plans and digital data from dental laboratories, that we are collectively, as a profession, overusing and misusing certain zirconia material applications in many of our patients and that there is a very good chance this will come home to haunt the profession, manufacturers, and dental laboratories at some point in the future. Again, it is not that zirconia, for example, is a bad material in itself; just like any material introduced before or after it, material selection and how it is used is vital to its success or failure. Any restorative material needs to be treatment planned and prepped for in optimal ways specific to the chosen material to ensure not only short-term but, more importantly, long-term success.

Q: Where do you see these materials going in the future?

A: In my opinion, we will continue to witness the introduction of indirect restorative materials that have increasing strength (biaxial flexural strength and fracture toughness) and aesthetics that will look more and more lifelike in patients’ mouths. We will also see new fabrication techniques and protocols, beyond CAD/CAM, as we move into the future. Recently, we have seen the introduction of a number of more translucent zirconia products that currently exemplify this trend.

Once again, with a good number of these products being introduced, all with slightly different material strategies (or “formulas”) that address the matter of natural translucency (in 2017, an HT zirconia material now includes the addition of fluorescence to increase the lifelike look of the material), which ones will be the long-term winners? Without any long-term in vivo evidence to back up the material that may be brought to market, no matter how thoughtfully done and with the best of intentions on the part of the manufacturer, how do we judge how these materials will perform over time? Perhaps our decisions are being based upon marketing in ads and online with only manufacturer/lab-based or manufacturer/lab-ordered data to back up the material claims; so how do we make the best choices within this new category of competing materials? How do we evaluate what products hold the best chance for success—or worse, failure—before they are permanently cemented into place? These are some of the salient and ongoing concerns in modern dentistry for all clinicians that need to be considered while balancing the need to keep up with the latest advancements.

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