Diagnodet *Laser Fluorescence Measurement*
Diagnodet *Laser Fluorescence Measurement*
Definition
A laser diod with a wavelength of 655 nm is beamed onto the tooth surface. It is absorbed by metabolites of intraoral bacteria in carious lesions and these metabolites emit a red fluorescence. The observed amount of fluorescence increases with increasing bacterial activity. This fluorescence reflected from the tooth surface is displayed on the device's screen as a number between 0 and 99. ¹‘²
Mechanism
The intensity of fluorescence of so-called fluorophores is measured. These are porphyrin-containing particles (porphyrins) that are released into the dentin as metabolites of bacteria or as bacterial components. These porphyrin compounds are stimulated by pulsed laser light of wavelength 652nm and begin to emit fluorescent light of a longer wave range (remission) via fiberglass to photodiode diagnosing measures the strength of the fluorescence².
*important*Impairment of specificity (false positive) due to occlusal discoloration and restorations³. Impairment of sensitivity (false negative) due to limited penetration depth of the laser to 1- 2mm with deep fissures and thick Enamel.
Indication
- Smooth-surface caries
- Occlusal caries, fissures
- Not recommended for approximal caries
References
- In situ and in vitro comparison of laser fluorescence with visual inspection in detecting occlusal caries lesions.
- Comparing the reliability of a new fluorescence camera with conventional laser fluorescence devices in detecting caries lesions in occlusal and smooth surfaces of primary teeth.
- Effect of dental material fluorescence on DIAGNOdent readings.
- Ashley, P & Attrill, David. (2001). DiagnosticsOcclusal caries detection in primary teeth: a comparison of DIAGNOdent with conventional methods. British Dental Journal - BRIT DENT J. 190. 440-443. 10.1038/sj.bdj.4800998.