I am writing in response to an article written by Dr. Joel Benk in the January 2004 issue of Dental Economics, titled "Chairside CAD-CAM dentistry as a profit-builder" (page 100). The image that precedes the article appears to include bundles of $100 bills. A cursory examination reveals at least three bundles of that denomination, which I estimate to be about 100 per bundle. I conclude the image to suggest a total of about $30,000. It is often said that one has only one opportunity at a first impression. My first impression of this CAD-CAM article is that the single most important aspect of this technology is not patient benefit, but operator profit. I am no Pollyanna, but it seems to me that a new treatment technology should have patient benefit as the first priority, not financial gain.
The article does at times suggest that patients might benefit from this CAD-CAM technology, but it is hardly convincing, and while it makes some truly audacious assertions, they are both highly contentious and devoid of corroboration.
The most inflammatory of Dr. Benk's claims are the suggestions of the longevity of restorations. Benk writes, "We can help patients preserve healthy tooth structure using ceramic restorations..." This is intrinsically false. The bulk of the work of dentists is the removal and replacement of amalgam restorations and new decay. For directly placed restorations, this can be done conservatively by the removal of only the diseased portion of the tooth. Generally, it results in a preparation that is undercut in a Class I or II because it is not necessary to remove excess occlusal tooth structure while removing the decayed part of the interproximal tissue. If placing an indirect restoration, it is necessary to remove far more intact tooth structure for no other reason than to create a path of insertion. Thus, the indirect restoration is inherently less conservative.
The most egregious assertion made by Dr. Benk relates to restoration longevity. Dr. Benk writes that these CAD-CAM restorations have the "promise" of lasting "two to three times the lifespan of an amalgam" and "at least five to six times the lifespan of a posterior composite fillingU" These are breathtaking claims, to say the least. Such sweeping claims demand evidence, but Benk's article is totally devoid of evidence. It would be of great value for readers to learn the evidence. There is no evidence that tooth-colored inlays demonstrate any superiority to direct restorations. In fact, in a seven-year study, Thordrup et al reported that direct restorations are the equal of tooth-colored inlays1.
Benk claims that this technology will save patients money, because "dentists often see failed crowns, root canals, bad extractions, etc." This statement implies that the use of the CAD-CAM technology will automatically result in superior restorations. How the use of CAD-CAM restorations will prevent "bad extractions" remains a mystery. One has to wonder why dentists who would perform such poor dentistry would suddenly be able to place CAD-CAM restorations with skill. It seems more reasonable to assume that if an operator would place a poor direct restoration or perform a "bad extraction," he or she is likely to place a poor CAD-CAM restoration as well.
Dr. Benk writes of the amount of money he saved by purchasing his CAD-CAM device, but he fails to include the cost of the CAD-CAM technology — which approaches six figures — and routinely is cited at about $2,300 per month. That $2,300 payment will be due no matter whether the patient flow supports it or not, and such pressure could easily be a temptation for CAD-CAM operators to allow their amortization schedules to affect their treatment plans. The fault lies not within the technology, but the financial pressure that it can exert. This type of technology might be well-suited to larger group practices and to those who already do a large number of indirect ceramic restorations. It would be useful to examine the patient records of those who purchase this kind of technology to determine the number of indirect ceramic restorations placed before the purchase of the CAD-CAM machine, and then again after the technology was installed. Were we to find an increase in the numbers of such restorations, the case could be made that patients serve the technology, and not the other way around. John Kanca III, DMDMiddlebury, Conn.
Rebuttal from Dr. Joel Benk
First let me say, I understand your interest to see corroboration with regard to content of the article, however, the article was written from my personal experiences, as is the nature of the editorial format of Dental Economics. There are enough clinical journals in the dental industry that cite reference upon reference, and I've always found it refreshing to read DE and learn about what is personally working for my colleagues. Nevertheless, for purposes of this rebuttal, I will accommodate your request because it's obvious you're not aware of the current state of the technology.
Secondly, let me say that I could write an entire article on the patient benefits of CEREC. Dr. Gordon Christensen's CRA report in November 1999 cites CEREC as having the least postoperative sensitivity of all restorations1. Other studies have corroborated2-3. The marginal integrity is right on point, too. In a later issue of the CRA Newsletter, Dr. Christensen states, "CRA research shows that CEREC restorations have margin adaptations equal to or better than laboratory-made restorations"4. Also, to challenge your point about my so-called "inflammatory claim" about the longevity of CEREC restorations, please note that the durability of CEREC restorations is well-documented5-11. The data available establishes ceramic restorations machined by the CEREC system as a clinically successful restorative method. Additionally, the studies find CEREC restorations lasting upwards of 10 years and still going strong because they only started testing them in 1987. My sincere belief is that CEREC restorations will continue to last much longer. It also should be noted that these studies were conducted on CEREC 1 restorations. The latest version — CEREC 3D — is light-years ahead! Other studies have suggested composite failing at four years12-13 and amalgam failing anywhere between five years14 to 10 years15. While I'm aware you could challenge these studies with your own reports, the point is that CEREC restorations are proving to be consistently durable. CEREC has been nothing short of excellent for my practice, and my colleagues who have integrated the CAD/CAM system will concur. Also, just ask my patients what they think of the aesthetic quality of their CEREC restorations, or, if you don't want to take their word for it, check out what other dental professionals have said about the quality.16-21
Furthermore, Dr. Christensen states: "The trend to over-cut teeth should be reversed"22. I believe this statement implies that clinically, we should try to retain as much healthy tooth structure as possible when doing restorative dentistry. The more natural tooth structure retained, the more the tooth is resistant to fracture. When the unfortunate clinical situation arises where endodontics is necessary after a restoration is placed, the tooth is no longer as structurally sound compared to the non-endo-treated tooth. Moreover, if that endodontically treated tooth has a catastrophic failure and extraction is necessary, the potential for fracture at or below the cervical line is greater due to canal widening, loss of the pulp chamber's roof, and the fact that endo treatment results in less physical dimension of the tooth. Therefore, when extracting endodontically treated teeth, they can easily fracture at or below the cervical line, resulting in a potential bad extraction for the patient.
To address your next concern, the reason I took the economic angle in the article was because the publication it was written for is Dental Economics. Also, I no longer have a monthly payment; my CEREC paid for itself within the first 11/2 years! I've saved an incredible amount of money with CEREC by reducing my lab bill, among other things. My production is up and so is my profitability. I'm not ashamed to make money when the patient is benefiting as well.
Again, let me reiterate, the focus of my article was to inform dental professionals what was working in my practice. I've been in practice for more than 24 years, and have a very loyal patient base. They are just as excited about this new technology as I am. Integrating CEREC was hands-down the best thing I ever did for my professional life, and it has made my personal life even better, too. I told my story in the January issue of DE in hopes it would inspire others to share in my happiness as well. In closing, the technology is proven, my patients love it, I'm having fun doing it, life is too short for bickering and reference slinging, and I've got some patients to take care of.Joel Benk, DDSAltanta, Ga.
Editor's note: References for Dr. Kanca's letter and Dr. Benk's rebuttal are available by request from Dental Economics.
Supports Dr. Benk's view
Congratulations to Dr. Joel Benk for his recent article on CEREC 3D and its positive effect on individual dental practices throughout the United States and, more important, the world. CEREC is an internationally recognized restorative system that is actually just catching on in the United States, as it already has in other countries such as Australia, Canada, and Germany.
I also have seen dramatic changes in my practice as I incorporated CEREC 2 five years ago. My initial experience with CEREC, although positive, provided a lot of learning and exposure to the CEREC method. Like anything else, my early failures with CEREC were not necessarily due to the CEREC, but rather with my application or understanding of the technology. The knowledge and experience gained by being one of the "early adopters" of CEREC has allowed me to see through my early successes how effective CEREC, applied correctly, can be to the business of dentistry. In those five years, I also have observed how it performs clinically in patients' mouths over time.
I find it necessary to report that seeing some of those early CEREC 2 restorations has driven home the observations and insights that many proficient CEREC dentists know to be true — CEREC restorations are performing well over time and are providing patients with alternatives that strengthen and extend the life of their teeth.
CEREC restorations have performed better in my practice than other contemporary restorative methods, including laboratory-processed indirect inlays, onlays, and crowns. They also are performing significantly better than direct resins and amalgam restorations.
I offer the following reasons why I, as an experienced user, find that CEREC technology has enhanced my ability to perform better dentistry —
1) There is less pulpal irritation as a result of the immediate restoration and no temporization, leading to less postoperative sensitivity. I have performed fewer root-canal procedures on CEREC-restored teeth than I did previously when restoring teeth with lab-fabricated restorations. Some CEREC users report a near 60 percent drop in root-canal procedures.
2) CEREC ceramics are more homogenous and less prone to human error introduced by laboratory procedures for comparable materials.
3) The unique nature of CEREC tooth preparations enhance the strength and durability of both the ceramic restorative and the remaining tooth structure.
These three unique traits are inherent only to the CEREC method, which non-CEREC dentists will not understand or be able to quantify.
Beyond the obvious economic implications, CEREC can provide a positive direction for a dental business because there is a definite, unquantifiable value placed on patients' time as well as patients' best dental interests being served. This concept is the key to a successful dental practice, regardless of whether you practice with CEREC.Chris Winterholler, DDSScottsdale, Ariz.
In the March issue of Dental Economics, the New Products section contained a spelling error that affected readers' ability to contact the manufacturer's Web site. On page 156, the correct spelling of the product is Airsonett Airshower.
The correct Web site address is: www.airsonett.com.
We apologize for any inconvenience caused by the error.
