Diagnodent Laser : A very effective tool to detect Dental Decay, near 100% accuracy

DIAGNOdent Laser : A very effective tool to detect Dental Decay, near 100% accuracy.

Years ago, 1992, I guess, while I was doing my PG in conservative dentistry from Nair, I read about Diagnodent Laser in a trade magazine and I walked into Kalabhai office and the device costed about 1.5 lacs – way beyond my budget. It was a huge amount then and also because I was a student. But I nurtured the dream and few years later bought my first Diagnodent Laser. Here‘s how my first case went. I told the anxious mother, look the reading is 25 but I don’t see clinically anything except an incipient pit and normally I would leave this tooth and observe. But my machine says there is decay underneath and we should go ahead, particularly because it was a newly erupted lower 6 and yes I also told her that I am nervous and it’s my first use. 46 to be precise, it’s still fresh in my memory although its been close to 14 years. I drilled with a round diamond point for half an mm and to my utter shock, everything was neat and clean. But the reading increased to 35.

Encouraged by the mother I ventured almost 1.5 mm, my heart was racing as everything seemed cool (no decay), but the reading went up to 45. I had begun cursing my stars. At 2 mm, it was whoa!, there was almost a 1.5 mm frank lesion. That day on I kept increasing my chairs and my Diagnodent Lasers. Sadly I believe there are just a few such lasers, may be fewer than 20 in the country still. This is in spite of the fact that I read somewhere that in Germany almost 60% dentists use Diagnodent Laser. In my clinic no patient leaves without laser check or during any cutting. Increases our time, but brings us a lot of business.

Dentists often experience anxiety when attempting to diagnose the phenomenon known as hidden caries. A suspicious-looking tooth presents a treatment dilemma for dentists. Should the tooth be opened up? What if no caries is found? Should the tooth just be watched or does that give caries more time to destroy the tooth’s surface?

The Diagnodent measures laser fluorescence within the tooth structure. As the incident laser light is propagated into the site, two- way handpiece optics allows the unit to simultaneously quantify

the reflected laser light energy. At the specific wavelength that the Diagnodent Laser operates, clean healthy tooth structure exhibits little or no fluorescence, resulting in very low scale readings on the display. However, carious tooth structure will exhibit fluorescence, proportionate to the degree of caries, resulting in elevated scale readings on the display.

To get consistent readings, it is essential to have a clean tooth. This is especially important when monitoring values at future examinations. We suggest that the teeth are cleaned thoroughly using any acceptable means. The use of a powder jet cleaner, e.g. KaVo PROPHYflex 3, is a rapid and effective method to clean stain and debris from complex occlusal anatomy.

Studies have shown the unit is equally accurate in both primary and permanent teeth.

DIAGNOdent laser

The DIAGNOdent operates at a wavelength of 655 nm. At this specific wavelength, clean healthy tooth structure exhibits little or no fluorescence, resulting in very low scale readings on the display. However, carious tooth structure will exhibit fluorescence, proportionate to the degree of caries, resulting in elevated scale readings on the display of the DIAGNOdent.

An audio signal allows the operator to hear changes in the scale values. This enables the focus to be on the patient, not solely on the device.

In a study conducted by Dr. Lussi of Berne University, Switzerland, general practitioners correctly diagnosed hidden fissure areas by visual inspection in only 57% of all cases. The same group achieved an impressive success rate of 90% with the DIAGNOdent. In fact, DIAGNOdent was far more accurate than any other method in the study including bitewing X-rays.

Traditional Caries Diagnostic Model: Low Sensitivity, High Specificity Low Sensitivity: Conventional diagnosis can miss significant amounts of decay.

High Specificity: Conventional diagnosis does not produce a lot of false positive diagnoses.

So if “Probe” doesn’t stick, it means, no caries.

“A sharp explorer should be used with some pressure and if a very slight pull is required to remove it, the pit.

DIAGNOdent Laser

Black, G. V. Operative Dentistry. Vol. I Henry Kimpton, London. 7th Ed, p32, 1924 should be marked for restoration even if there are no signs of decay.”

“Probing found unreliable in finding fissure caries.”, Penning C, van Amerongen JP, Seef RE & ten Cate JM.

Validity of probing, for fissure caries diagnosis.

Caries Res 26(6):445-9, 1993

“… decay is difficult to detect in radiographs unless larger than 2 mm to 3 mm deep into dentin, or 1/3 the bucco-lingual distance.” ROCK WP, KIDD EAM,Br Dent J. 164(8): 243-47, 1988.

Caries is regularly found beneath a seemingly intact enamel surface, frequently the diagnosis of occlusal caries is less than straightforward, Chan DCN. Current methods and criteria for finding decay in North America.

J Dent Ed 57(6):422-425, 1993

The reliability of carious lesion diagnosis by sharp explorer compared to diagnosis of carious lesion by histological cross section was 25%. A seemingly intact occlusal enamel surface may conceal an extensive lesion of the dentin. AL-SEHAIBANY, WHITE & RAINEY, J Clin Pediatr Dent 20(4):293-298 1996