Performance and reproducibility of a laser fluorescence system for detection of occlusal caries in vitro

Resident’s Name: Dan Boboia Date: 2/20/09

Article title: Performance and reproducibility of a laser fluorescence system for detection of occlusal caries in vitro

Author(s): Lussi A. et al

Journal: Caries Res

Volume (number): 33: 261-266

Month, Year: 1999

Major topic / Main purpose: Assess the validity of a new laser fluorescence device (Diagnodent) histologically for the detection and quantification of caries on macroscopically intact occlusal surfaces, determine optimum cut-off points for different stages of the caries process, and assess reproducibility of results.

The diagnostic approach of the Diagnodent is based on the caries-induced changes in teeth leading to an increased fluorescence at specific excitation wavelengths. The intensity of fluorescence depends on the wavelength of the light as well as the structure and condition of dental hard tissues.

Methods and Materials

105 extracted teeth with macroscopically intact occlusal surfaces were measured by a single examiner using both a laser fluorescence device and an Electronic Caries Monitor.

Teeth were examined histologically to determine specificity, sensitivity, and likelihood ratio at the D2 (caries extending through more than half of the enamel thickness) and D3 (caries involving dentin) levels.

Reproducibility of Diagnodent was determined by having 11 dentists record the different measurements at the same site on a separate set of 83 extracted molar teeth
Results

Histological examination revealed 21 teeth --- caries free, 15 teeth --- caries extending up to halfway through the enamel (D1), 31 teeth --- caries in the inner half of the enamel (D2), 28 teeth --- caries in outer half of dentin, 10 teeth --- caries extending into inner half of dentin

The laser device ranged from 72 - 87% (specificity) and 72 - 87% (sensitivity). ECM (Electronic Caries Monitor) ranged from 64 - 78 % (specificity) and 87 - 92% (sensitivity). Compare to 30% sensitivity for clinical visual methods of caries detection of macroscopically intact occlusal surfaces.

Higher specificity values for the laser at D2 and D3 levels compared to ECM

False-positive readings can occur with plaque / calculus deposits in the fissure and/or tip

Conclusions

The Diagnodent has a higher diagnostic validity than the ECM

Measurements using this device are highly reproducible (certainly higher then ECM or visual diagnosis)

This device could be a valuable tool for the longitudinal monitoring of caries and for assessing outcome of prevention

Assessment of article Good Article