a unique development in the history of Dentistry 

We Find Decay the Easy Way

With a new sophisticated electronic laser scanner we are now able to detect decay earlier so that bacteria never gets a chance to enter the nerve and cause more unhealthy damage.  The accurate evaluation of stained teeth has up until now been a dilemma for the dental profession and patients.  Many practices still rely on outdated modes of decay detection, mostly a detection of a "stick" with a dental  pick.  Research shows this technique has a relatively low accuracy.  With this method the cavity had to be larger than the tip of the pick before we could detect it.  This was okay when a drill was all we had to remove the cavity with; the cavity had to be bigger than the size of the drill bit.  Today with newer Air Abrasion Technology we can prepare a very small filling for the smallest of tooth decay.  We therefore needed a better and more sensitive device to detect this decay.  The Diagnodent laser from Kavo provides that technology.  We can now detect cavities smaller than the tip of the dental picks.

What are the Benefits to You?

Laser Reflection Spots Imperfection - How it works

 

 

 

 

DIAGNOdent technology uses a simple laser diode to inspect your teeth, comparing reflection wavelength against a known healthy baseline wavelength to uncover decay. How? First, we aim the laser onto one of your healthy enamel tooth surfaces to give us a benchmark reading. Then, we continue on around your mouth, shining the laser into all suspect areas. As the laser pulses into grooves, fissures and cracks, it reflects fluorescent light of a specific wavelength. This light is measured by receptors, converted to an acoustic signal, evaluated electronically to reveal a value between one and 100, then displayed on a screen. Anytime the laser encounters a surface that reads differently than the healthy baseline value, it stimulates emission of fluorescent light of a different wavelength and beeps. A reading of 10-20 indicates some enamel softening, pointing to a potential problem area that merits close monitoring. A reading of 21-100 indicates a definite area of decay requiring a filling.  It detects the invisible.

Early Detection and then Precise Correction 

Using DIAGNOdent technology allows us to catch areas of decay sooner and with more precision.  Not only can it help prevent the spread of decay, but catching decay early means any fillings required are simpler and shallower, preserving more of the tooth. This allows us to use minimally invasive filling procedures, such as drill-free  air abrasion. In many situations we are finally able to objectively monitor any suspicious areas without repeated x-rays, harm to tissues, or the need for protective measures.  On the left is a picture of outdated probing of a tooth missing the decay that is lower than the pick can reach.  On the right is a picture of how the laser would detect the decay indicating early preventive treatment.

          

How accurate is it?

In a study conducted by Dr. Lussi of Berne University, Switzerland, dentists correctly diagnosed hidden decayed areas on the tops of teeth only 57% of the time.  The same group achieved  90% accuracy with the Diagnodent.  In fact, the Diagnodent was by far the most accurate of any method in the study including cavity detecting x-rays.  According to Dr. Tom Orient of the Center for Esthetic Dentistry "if there is decay, there is a change in the wavelength.  you get a reading of zero to 100 and are able to tell not only where the decay is, but how deep it is, and how much there is."  He said "certainly we'll see decay if it is large with conventional means, but that's too late.  At that point, you're looking at a very difficult restoration, a large filling or in some cases even a root canal."  The graph is a summary of the results of the study: 

Laser Flouresence in Decay Detection:

   

Decayed Molar       Diagnodent          Scanning        Restored Tooth

 

      Scanned Areas                 X-ray of Decay                Staining of Decay that Spread

   Cross Section of Decay    Near the Nerve of the Tooth

History:

Laser Caries Detection
  10/19/00
Jon Dunn, DDS

Editor, DentalDidactics.com Continuing Education

 

Reflect for a moment on the common maxim; If all you have is a hammer, every problem becomes a nail. The current dental equivalent might read; If all you own is an explorer, the only caries you diagnose are “sticks.”

For decades, the diagnostic paradigm of caries detection has relied upon tactile feedback from a sharp explorer. Unfortunately, this left many an enigmatic stained pit or fissure improperly diagnosed or ignored, resulting in non-conservative restoration or endodontic intervention at a future date. Many a conscientious practitioner, eager to provide ultra-conservative treatment and prevent unnecessary restoration has overlooked or misdiagnosed pit and fissure caries due to the limitations of the dental explorer. Only now is research unveiling the reasons for these missed diagnoses.

With the advent of fluoridation, caries rates dropped significantly; however, the nature of caries changed dramatically. While the outer enamel shell of a tooth’s clinical crown has become more caries-resistant, the pits and fissures still allow ingress to damaging micro-organisms. Alarming carious destruction is often observed upon opening seemingly innocuous pits and fissures, as the anatomical constrictions of pits prevent adequate access to the tip of a dental explorer.

The reintroduction of air abrasion technology to the profession significantly improved the successful discovery of “hidden” pit caries, but still necessitated the invasive exploration of questionably stained anatomical pits. Conservative sealants could be placed upon negative caries findings, but still left patients with the impression that we were definitely unsure of our initial diagnosis, and quite correctly so.

Now we have entered a new diagnostic era with the introduction of laser fluorescent caries detection. Represented commercially by the KaVo DIAGNOdent, this technology allows us as clinicians to evaluate formerly enigmatic stained pits with confidence. A simple digital readout gives reliable diagnostic feedback, allowing the detection of demineralized dentin that was formerly undetectable with tactile or radiographic examination. A thin laser beam is emitted from the instrument handpiece and causes carious dentin to exhibit fluorescence, read by the instrument’s electronics and translated into a digital reading. On an individually calibrated scale; a reading of 10-15 warrants air abrasion exploration, while higher numbers (typically 15 to 35) indicate the need for more extensive preparation. In my practice, the DIAGNOdent readings have been incredibly accurate and clinically reflective of the presence of active caries in teeth explored. The DIAGNOdent has been a remarkable addition to our diagnostic armamentarium and has finally allowed us to securely differentiate between active lesions and innocuous stains. Clinical studies indicate that established practitioners were able to detect hidden fissure caries by visual and tactile exploration in only 57% of cases, while the same group identified the caries successfully in 90% of cases utilizing the DIAGNOdent technology.

The DIAGNOdent is a major step forward in caries detection and should soon represent another milestone in the “standard of care” for conservative restorative treatment. It also allows dentists, hygienists and auxillaries to accurately gather objective numeric data regarding pits and fissures and chart their findings. Additionally, its petite size, light weight and battery operation allow the unit to be easily transported between operatories, eliminating the need for multiple office units.

The DIGNOdent effectively closes the door on the era of the suspicious “watch” and provides us with a marvelous opportunity to offer patients early, ultra-conservative and objectively diagnosed treatment. In my practice, after utilizing laser fluorescent caries detection, I would feel “blinded” retreating to the use of a humble explorer to diagnose (or misdiagnose) pit and fissure caries.

Dr. Jon Dunn received his DDS degree in 1983 from the University of the Pacific. He maintains a premier private practice in Santa Barbara, California devoted to high technology adult preventive and esthetic restorative dentistry. Dr. Dunn is the founder of DentalDidactics.com, an educational company providing online access to current research for dental professionals worldwide. Dr. Dunn’s AGD and DANB-approved courses are available at: www.DentalDidactics.com

Lussi, A; Performance and Reproducibilityof a Laser Fluorescence System for Detection of Occlusal Caries. Caries Research 33:261-266, 1999.

Kordic, A; Reliability of Noninvasive Detection of Fissure Caries. J Dent Res 79;#429, p. 197 (IADR Absracts, 2000).

Suzaki, A; Study on Efficacy of Laser Caries Diagnosis. J Dent Res 79 #435 p.198 (IADR Abstracts, 2000).

Summit, J; Accuracy of Various Diagnostic Methods in Detecting Fissure Caries. J Dent Res 79 #433, p. 198 (IADR Abstracts , 2000).

Research

Validity of Probing for Fissure Caries Diagnosis

 

By C. Penning, J.P. van Amerongen, R.E. Seef, and J.M. ten Cate
Department of Cariology and Endodontology. Academic Centre for
Dentistry. Amsterdam. The Netherlands

Abstract

One hundred extracted molar teeth with discolored fissures but without any visible carious cavitation were selected from a large supply, using standardized criteria. The teeth were mounted, placed on a mechanical balance, and probed with a force of 500g in ever fissure, at as many places as possible. 

Every time the probe was found to stick, the spot was marked. After probing color slides were made of the occlusal faces. Subsequently, the crowns were embedded in epoxy resin. 700um thick sections were cut in a facial-lingual direction with a diamond wheel. From the sections, x-rays were taken which were scored as follows: a measuring grid wad placed on the x-ray image of a section, and the carries score (0-4) for every millimeter was determined. By scoring every section of a tooth in this way, an overview was obtained of the location of all caries lesions in the occlusal surface. By comparing this overview with the color slide of the tooth, the relationship between the sticky spots and the lesions was visualized. 

The results indicate that only 24% of the caries lesions were discovered by probing for stickiness (low sensitivity), but that the probe seldom stuck in a sound fissure (high specificity,> 99%). Probing proved to be unreliable for the diagnosis of fissure caries.

*    *    *

For this reason, we have added the laser caries detector,  to our practice's diagnostic aids.

Laser Readings vs Recommended Treatment:

KaVo DIAGNOdent
Correlation of DIAGNOdent Values to Possible Course of Action
Possible Course of Action*
DIAGNOdent Values No Action Preventive Therapy Record & Monitor Sealant Preparation
0 to 5 x        
5 to 10 x x      
10 to 15 x x x x  
15 to 20   x x x  
20 to 25   x*** x x x**
25 to 30   x*** x x x**
30+   x***     x

* Taken from Lussi; See "Research Supporting DIAGNOdent Scale Readings," (page 6 of Manufacturers instructions)
** In unusual cases of virulent disease, preparation may be a course of action when a value between 20 - 30 is recorded.
*** Regardless of course of action taken to treat a specific lesion, preventive therapy may be indicated based upon caries risk.

Discussion: CRA's work indicates that the DIAGNOdent course of action scale appears to be overly conservative in its recommendation to withhold excavation until a DIAGNOdent reading > 20 is observed. This recommendation is not to excavate until > 20, yet 39% of the time carious lesions 2mm deep were found for readings 8 - 18, & 22% of the time lesions 3mm deep were found for readings 8 - 18. These same lesion depths were found 35% of the time & 23% of the time at readings of > 20.

CRA data agree with serveral reports published by Lussi, et al:
1. (Lussi, A, et al.: "Performance of a Laser Fluorescence System for Detection of Occlusal Caries", 45th ORCA Congress, 1998, Abst.#87, p.297)
2. (Lussi, A., et al.: "Performance and Reproducibility of a Laser Fluorescence System for Detection of Occlusal Caries in vitro." Caries Research, 1999; 33:261-266)
3. (Lussi, A., et al.: "Reproducibility of a Laser Fluorescence System for Detection of Occlusal Caries." 45th ORCA Congress, 1998, Abst. #88, p. 297)
4. (Lussi, et al.: "Clinical Performance of the Laser Fluorescence System DIAGNOdent for Detection of Occlusal Caries." 46th ORCA Congress, 1999, Abst. #55, p. 299)
5. (Lussi, A., and Hibst, R.: "Methods for Occlusal Caries Detection Used in Daily Practice," Indiana Conference 1999)
6. (Lussi, A.: "Clinical Performance of the Laser Fluorescence System DIAGNOdent for Detection of Occlusal Caries" (in German), Acta Med Dent Helv 5: 15-19 2/2000)

Other significant published research on the evaluation of the DIAGNOdent:
1. (Shi X-Q, Welander U, Angmar-Mansson B: "Occlusal caries detection with KaVo DIAGNOdent and radiography: An in vitro comparison." Caries Res 34:151-158,2000
2. (Gerry Ross: "Caries Diagnosis With The DIAGNOdent Laser: A User's Product Evaluation." Ont. Dent, Vol 76 NO2, March 1999, pp 21 - 24

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