Digital Diagnostics Meets Old Amalgams Dr. Andrew Spector

We have all heard it: “We have a wealth of dentistry sitting in our charts, if you just hone your case presentation skills you will reap the benefits,” or, “Buy this technology and you will do more procedures.” These statements do have some merit; however, the reality is most of the treatment is probably still sitting there. Why? The fact is, we don’t diagnose and present all treatment with the same level of conviction. Our patients already trust us. It’s our level of conviction that the tooth “needs to be” dealt with that moves the patient to have treatment done. Our lack of conviction lets them “off the hook” allowing patients to wait for that impending emergency, leading to broken teeth, root canal, posts and crowns. The goal of this article is to help you refine your diagnostic philosophy, to show how today’s technology has redefined the diagnostic process, and to help you develop the conviction you need to diagnose the replacement of old amalgams, before radiographic evidence of decay. This is not a discussion of materials selection.

In our practice, we have an 11-year track record with pressed ceramics. Three years with lab-fabricated restorations and eight years of CEREC dentistry. A great number of CEREC onlays are diagnosed out of our hygiene operatories. Our hygienists have seen the results and have conviction that this is the best treatment for our patients. In fact, I have had CEREC restorations placed in my mouth, an example of my conviction in my treatment philosophy.

It is time to move away from a 100-year-old diagnostic technique. Fluoride supplements have made enamel surfaces impervious to our explorers. Further, the limitations of film-based radiography are well documented. Radiographic evidence of decay occurs only after a significant [30%] decalcification of tooth structure. Digital radiography is helpful; however, that bright white wall of silver blocks our view of internal buccal and lingual decay. I believe we need to gain trust and faith in other methods of diagnostics.

The time has come to not only move to, but also rely on video/laser/and light diagnostics as the core of our examination process. Our ability to visualize cracks, uncover evidence of early decay, and reveal defective margins has been maximized by today’s technologies. We now must use them not as an adjunct to examination, but as the core tools of our diagnostic process.

The intraoral camera is the first staple a doctor needs to enhance diagnostics. It amazes me to date how many doctors who attend our seminars don’t have intraoral cameras, or have them but rarely use them. The obvious value of the intraoral camera as a “diagnostic” tool has not yet been embraced by our profession. Let me be clear: There is a difference between a “diagnostic tool” and a “presentation tool.” I believe that many doctors feel that an intraoral camera is there to help present or sell dentistry. Thus, for fear of “selling” they let it collect dust. I maintain the intraoral camera is an essential diagnostic tool that needs to be present during an examination as if it were a mirror and explorer. Let’s look at some examples.

Evaluate the clinical picture of tooth #20 which simulates the unaided eye (fig. 1) and the digitally enhanced x-rays of tooth #20 (fig. 2). What would you do?

Next, evaluate the video magnified intraoral camera picture (fig. 3). Would you treat it? Note the gray areas under the cusps. Is it decay? Is it an “amalgam tattoo” or “show through” of the amalgam? Will it be a “watch”? Now look at what’s really there (fig. 4) the “gray” is decay! It’s definitive. It always is. We have done this over and over again, thus developing the conviction in our intraoral camera pictures to diagnose and present treatment definitively. Not “this looks a little beat up, it should come out soon.” But “Mrs. Jones this large restoration has decay around it…notice the gray areas on the picture. The tooth needs a (insert restoration of your choice), which will restore it for the long term.”

When a patient breaks a tooth, and you say: “Ms. Jones you need a crown,” they say, “OK Doc.” This presentation is without complication because both you and the patient perceive the need. Video diagnosis demonstrates the need! It is there staring at you and the patient. This is not discretionary dentistry, patients will do the work they need. We know that the objections are going to be Time, Money, and Pain. Time issues are irrelevant in our practice for day-to-day, bread-and-butter dentistry since we embraced CEREC technology eight years ago. We can complete a quadrant of onlays with complete control of occlusion in one to two hours, depending on the number and size of the restorations to be done. Need for equilibration can be accomplished prior to numbing the patient. Further, a quadrant of quality dentistry can be gotten down to under $100 per month with today’s financing programs. Post-op sensitivity has all been eliminated with single-visit CEREC care and the advent of sixth and seventh generation self-etching bonding techniques. Bottom line is CEREC restorations are minimally invasive, have properties similar to enamel, and they last. I have seen it in my practice and there is 20 years of research available to support it. This is the basis for our conviction in treatment philosophy, and we communicate this to our patients on a daily basis.

Gaining the conviction to diagnose from video examination takes time to master. When to pull the trigger on a case or quadrant is developed over time. Be observant during your day-to-day dentistry. For about a month, whenever you remove an old amalgam, look at your pre-op clinical photo and note the gray areas around the margins. Correlate the position of the gray area in the preclinical shot to the brown decay underneath. Within a month you will have conviction.

When asked about integration of technology the question often comes up as to which intraoral camera to buy. Unfortunately, I have not evaluated all of them. But I will say this: If you are just thinking of using your intraoral camera for presentation it probably does not matter. However, if you are using it for diagnostic purposes, the higher the resolution the better. You want to be able to visualize the gray areas underneath the cusps. Diagnosis of decay depends on this.

Ease of access to your intraoral camera is also paramount. If your intraoral camera is not portable think of replacing it or adding a multi-op system to cover the rest of the office.

We cannot be consistent in our diagnosis if we don’t have all our diagnostic tools handy at an instant. It will be the best investment you ever make. If it is not accessible, it will not be used. Durability is also a factor. In a busy practice that has integrated the technology properly, the camera will be used eight hours a day and bounce from room to room.

The ability to print your pictures easily is essential. When we submit our CEREC dentistry to the insurance companies we include a picture, a narrative, and an x-ray. The moment you forget the intraoral pre-op picture, the odds your procedure will be downgraded to an amalgam fee grows exponentially. A central printer, if you have a network, is handy. However, if you are not networked, individual video printers have come down in price and could be placed in each operatory. If you are submitting electronically, there are clearing houses that will accept your images online eliminating the need for printing. Storing your images is less important, but a great benefit of having a network. We use EagleSoft Clinical/ Management software in our office which lets us access all our images from one portal making x-ray, image comparison, and insurance submission an absolute breeze.

The next diagnostic technique dentists should have in their hip pocket is video transillumination. It’s used to diagnose destabilized tooth structure (cracks/craze line/impending fractures) incipient, and recurrent decay. The most advanced method of transillumination is the digital fiber optic transillumination (DIFOTI). Manufactured by EOS, DIFOTI is approved by the FDA for diagnosis of incipient, frank, and recurrent caries. It renders radiation-free images of the occlusal, proximal, and smooth, surfaces. The 1997 Journal of Caries Research states this technology “enables dentists to discover or confirm the presence of decay that cannot be seen radiographically, visually, or through use of an explorer. (Schneiderman A, E0lbaum M, Shultz T, et al. Assessment of dental caries with Digital Imaging Fiber-Optic TransIllumination (DIFOTI): in vitro study. Caries Res. 1997;31(2):103-10).

The use of DIFOTI is quite simple. Recently redesigned, DIFOTI’s light source is now in the handpiece itself making it a lightweight, portable wand that uses a simple USB connection. The software, laid out like a dental chart, makes it quite user friendly. A finger-activated wheel located on the base of the wand has eliminated the need for a foot pedal allowing you to navigate through a DIFOTI exam swiftly and easily. Reading the images is like reading an x-ray. Black around the margins of your restoration is decay.

Again, look at the DIFOTI image of tooth #20 (fig. 5). The black decay around the buccal margin is obvious. EOS encloses a tutorial to help you gain the skills needed to interpret the images correctly.

DIAGNOdent laser caries detection must be mentioned as it is an adjunct around old amalgams and the new standard of caries diagnosis for previously unrestored teeth.

KaVo has also come out with transillumination device (DiaLUX Probe 2300 L), which uses a fiber optic light source for excellent visualization of destabilized tooth structure in the anterior region.

In the grand scheme of things compared to many technologies the intraoral camera, DIFOTI, KaVo’s DIAGNOdent and DiaLUX Probe are cost effective technologies that are easily paid for through proper diagnosis and care of your patients.

Let’s look at a case that demonstrates early detection and minimal invasive care.

The patient presented for routine recall examination with bitewing x-rays. Intraoral camera pictures of each amalgam and selected DIFOTI images were taken. Once again, notice the absence of decay on the x-ray (fig. 6) even when inverted and colorized. Think about what you would do if the explorer did not stick and you were looking with the unaided eye. Note the gray areas on the mesial buccal and occlusal margins on the intraoral camera picture of tooth #19 definitive decay (fig. 7).

Next, evaluate the occlusal DIFOTI image. Look at the black area under the mesial buccal cusp as well as the gray around the facial filling: definitive decay (fig. 8). Tooth #19 was treatment planned for a MOB CEREC restoration using Ivoclar Vivadent’s leucite glass ceramic, ProCAD. A pre-op optical image was captured to record the patient’s natural copal form for use with CEREC 3D’s simple correlation technique (fig. 9). After removal of the restoration, definitive decay was observed (fig. 10). A simple optical image of #19’s preparation was captured (fig. 11). The restoration was designed in three to four minutes with the CEREC software duplicating and enhancing the patient’s original cuspal form (fig. 12a). The restoration was cemented with Ivoclar Vivadent MultiLink automix cement, which has shown immediate bond strength’s ranging from 30-37 mpa (fig. 12b). Polishing was accomplished with simple rubber wheels.

In another case, the patient presented for routine recall examination. Intraoral camera pictures were taken of each tooth that had prior simple restorative work. Evaluate the x-ray of tooth # 28 (fig. 13). Is there any evidence of decay? The patient had lived with the overhang not wanting to replace the old amalgam because there was no decay. No significant periodontal reaction had occurred. Now look at the Diagnostic Video Image (fig. 14). Decay under the mesial buccal cusp and a fracture line propagating on the mesial. An MOD CEREC restoration was treatment planned. Now let’s look at how the video picture correlates to the decay underneath (fig. 15). Decay noted under buccal cusp, are you gaining some conviction?

An MOD CEREC preparation was completed and an optical impression was taken (fig. 16). A virtual model and restoration was generated and occlusion controlled (fig. 17). Figure 18 shows the completed CEREC restoration after simple polishing.

Since I embraced the concept of minimally invasive dentistry in 1994, I have seen the many benefits of early detection and conservative care. Diagnosing decay at its inception and uncovering defective restorations at the point of initial breakdown is the standard of care in dentistry. Because this cannot be done by traditional means, we must bridge this diagnostic void through technology. Using today’s advanced adhesive technologies we can consistently preserve more of the patient’s enamel leaving them in a more stable long-term situation. Minimal invasive technique and philosophy can be applied to every aspect of our practice affording our patients previously unheard of benefits and in turn significant practice growth. From a restorative standpoint minimal invasive care is supported by definitive early diagnosis. We must embrace this in our practice and invest in our diagnostic capability to best treat our patients.

In 1990, Andrew M. Spector DMD, FAGD, FICOI graduated from the University of Pennsylvania School of Dental Medicine. He served as clinical associate professor at New York University, teaching surgical and prosthetic implantology from 1996–1999. He also is a Graduate of the Americus Center for Aesthetic Dentistry. He has taught Basic and Advanced CEREC dentistry to users of the technology for Patterson/Sirona for over 5 years. In 2003, Doctor Spector founded D3 Practice Growth Seminars™. Dr. Spector can be reached through e-mail at cerectrainer@aol.com.