The Evidence That Defeats Doubt

Although I have been in private practice for 21 years, my involvement in dentistry started back in 1978 when I first worked as a dental assistant. That’s a long time… However, a good number of my close colleagues have acquired this many years of service and more. Many may believe we already know it all, but in some cases, just the opposite is true.
While the principles and quality standards that we were all taught in dental school haven’t changed, I’m not doing anything the same way as I did when I was a dental student. Procedures, materials, and especially the technology of dentistry have changed dramatically and continue to evolve. We can better help our patients and gain the most from our profession by evolving as well.
I have engaged in some quite heated philosophical discussions about continued learning in our profession. One colleague and I went our separate ways because we could not overcome fundamental differences in our approaches to diagnosing caries. He stated that if the explorer will not catch in a tooth, and if the radiograph does not show caries, you do not touch the tooth. I felt just as strongly that he was wrong, and backed my position with evidence. He contended that since this was the way he was taught in school (probe and radiograph), no other options were viable. He had stopped learning and was not taking advantage of the important and useful technology available to dental practitioners.
For all dentists who embrace this technology, there can be a tremendous reinvention for their practices. One such technology, laser caries detection, gives the assurance of knowing how and when you should proceed clinically. It provides another benefit by becoming an automatic second opinion when patients have doubts about your diagnosis and treatment proposals.
The Dale Carnegie organization presents 3 words that I think are magical: evidence defeats doubt. Why should you invest in this technology? One of the most defeating experiences for practitioners is to present a treatment plan to a patient, in essence saying, “I am offering you the best of my care, skill, and judgment, my best opinion,” and then hear the patient say, “Let me think about it.” Or worse, “My last dentist didn’t tell me this. You must need a new car.” This type of response can be quite humiliating.
In this situation, the use of laser caries detection offers the automatic second opinion. It is evidence that was unavailable in dentistry until the last several years. You can either unsuccessfully probe at a dark area of a tooth in a nonsmoker, noncoffee drinker, and think, “Well, I don’t know about this.” Or you can gain quantitative information that will allow you to better determine how to treat or not to treat the tooth. Even better, your patient is right there with you to witness your discovery.
This technology is more than 90% accurate in identifying potential problem areas on occlusal surfaces before they can be detected through radiographs or the use of the explorer. Mechanically, the unit works by measuring caries fluorescence within the tooth. A laser is shone onto the tooth’s surfaces, and the system analyzes reflected light to determine the presence and amount of decay. The results are displayed in numbers on the LCD screen on the console of the standard unit, or on the handle of the cordless “pen” unit, the one my hygienists use. Along with the number display, there’s also an audible sound that increases in intensity as the carious lesion increases in size. Depending on the number, I can choose to monitor the situation over time or proceed with immediate treatment.
The following cases demonstrate the importance of laser caries detection in clinical practice.

Figure 1. Tooth No 29: suspected possible decay, but it is not detected clinically.

Figure 2. DIAGNOdent readings show that restorative treatment is not warranted.

Figure 3. The initial baseline reading for the patient, which indicates a healthy tooth.

Figure 4. Tooth No. 3: suspected decay, however no explorer catch.

Figure 5. The reading is 32, thus warranting further investigation.

Figure 6. After initial preparation, caries is evident.


Figure 1 shows the mandibular right second premolar of a 32-year-old patient. I am unable to catch the apparently stained area with an explorer. The reading for this tooth using the caries detection device (DIAGNOdent [KaVo]) is 08 (Figure 2). According to manufacturer’s guidelines established by independent research and the initial baseline reading for this patient (Figure 3), this reading warrants no restorative treatment to the tooth. However, I could confidently provide preventive services for the tooth knowing that caries is not present.


Figure 4 shows the maxillary right first molar of a 29-year-old patient. I am unable to catch the area with an explorer. The reading for this tooth is 32 (Figure 5). Using the tested guidelines, this tooth warrants investigation. Figure 6 shows the tooth after initial preparation; caries is evident. The caries is removed, and the tooth is then fully prepared (Figure 7) and restored (Figure 8). Please note: another application for the detector is to use it intraoperatively to confirm all the decay is removed.


Figure 9 shows the mandibular left second molar of a 25-year-old patient. I am unable to catch the area with an explorer. The reading for this tooth is 55 (Figure 10). According to guidelines, this tooth warrants restorative procedures. Figure 11 shows the tooth after initial preparation; caries is abundant. The caries is removed, and the tooth is fully prepared and restored (Figure 12).

Figure 7. Caries removed, final preparation.

Figure 8. Final composite restoration.

Figure 9. Tooth No. 18 is clinically suspicious, however there is no explorer catch.

Figure 10. Tooth No. 18 has a DIAGNOdent reading of 55, which warrants restorative preparation.

Figure 11. Tooth No. 18: initial preparation, gross decay.

Figure 12. Tooth No. 18: caries removed, final preparation, tooth restored.


I am a big believer in minimally invasive dentistry. I truly think that laser caries detection is one of the best tools for helping us preserve tooth structure. As life expectancies increase and the population keeps its teeth for a lifetime, taking the tooth of someone in his or her teens or 20s and blasting off half the occlusal table for an amalgam is unconscionable. Doesn’t it make sense to know the extent of caries before we cut into teeth?
Think about this related technology’s effect on patients and practices…for anyone who uses an intraoral camera as part of diagnostic discovery with (not on) patients, you know that case acceptance is higher than without it. I had my own realization regarding intraoral cameras back in 1991. My equipment representative repeatedly asked me to consider a camera, stating that it could help build my practice. I told him that I was already doing well and just didn’t need one. However, eventually I decided to invest in a few cameras. We hooked up the intraoral cameras in the morning, and that afternoon we used them on our recall patients. Four of these patients were those from whom I’d received a “let-me-think-about-it” response after explaining that they should have amalgam restorations replaced with crowns. The 4 patients booked a total of 8 crowns that day!
It was this “wow” sledgehammer experience that sold me on the use of intraoral cameras the very first day. Oliver Wendell Holmes  said, “The mind, once expanded by a new idea, never returns to its original size.” I’ve never seen my dental world in exactly the same way since then.
I feel just as strongly that laser caries detection provides this “wow” for my practice. Now we use the intraoral camera and DIAGNOdent as part of our new-patient experience, along with a consultation, thorough exam, and digital radiographs. I begin my session with a new patient by first meeting with him or her in one of our private consultation rooms. I am the first one to see the patient. I take time to speak with the patient to learn where he or she is in life and to gauge the patient’s awareness of the importance of dental health. I also inquire as to why the patient left his or her last dentist. Virtually all the people I see state that they have never had a dentist sit down and talk with them first. Over and over again these new patients tell me that the reason they left their last dentist was because “he was always pushing crowns” and other dental work. When I ask if they think they need these restorations, typically they state, “I don’t know.” This tells me that the dentist was not using the latest in technology—imaging and caries detection—to create a sense of trust. These tools also allow us to create a state of urgency during which the patient asks for our care, instead of us feeling like we’re “selling.” We are now able to offer evidence that overcomes the patient’s doubt.
During the next step, I move the patient to an operatory, where we take the necessary digital radiographs. Digital radiography provides the next positive touch point impacting how these patients now feel about the level of service I’m providing. I use the intraoral camera for a preclinical tour of the mouth and clinical exam—providing another key touch point. If I’m presented with a suspicious area on a tooth, this gives me the perfect opportunity to zero in with the camera. Usually patients are extremely curious about these areas, especially if this is the first time they’ve seen video of their teeth. I then take an explorer to the area.
For the dark areas where the explorer doesn’t catch, I enlist the help of my laser caries detection system. I first explain what the unit is used for and how it responds. I ask patients to hold the controls of the unit right in front of their faces, and as I go around their mouths, the unit begins to sound. The higher pitched the sound, the higher the numeric value, and the higher the indication of caries.
This is when evidence defeats doubt every time. The patient has a digital x-ray and color picture displayed on the monitor, and the DIAGNOdent is wailing. The response is always the same. The patient says, “You have to fix this!” And I am always happy to comply.

Dr. Hyman lectures throughout North America at every major dental meeting and he has received feedback often rating him as the top speaker. He serves on the surgical staff of Moses Cone Health System in his hometown of Greensboro, NC, where he has a busy family and cosmetic dentistry practice. He teaches at the Pankey Institute in Key Biscayne, Fla, and at his undergraduate and dental school alma mater, the University of North Carolina School of Dentistry, where he serves as an adjunct associate professor. He is listed in Dentistry Today’s Top Clinicians in Continuing Education and can be reached at (336) 282-8850 or This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

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