The intra- and inter-examiner reliability of quantitative light-induced fluorescence (QLF) analyses

Abstract

Objective To assess the reliability of the analysis stage of quantitative light-induced fluorescence (QLF). The QLF analysis involves subjective input from the user and this study examines the influence of this on the reproducibility of the QLF data. Method QLF images were taken of 20 human molar teeth that had been previously subjected to a demineralising solution (phosphoric acid 37%) to create artificial white spot lesions on their buccal surfaces. Following examination of the images, 16 were chosen to represent a range of lesion size and severity. Three copies were made of the images and each was allocated a different filename. 10 examiners in three centres were asked to analyse each of the 16 images on three occasions, with at least seven days between each attempt. Simple instructions describing the analysis procedure were supplied and examiners were asked to adhere to these directions. Examiners were asked to rate each of the 16 teeth on their first attempt both quantitatively (5 point scale) and qualitatively in terms of difficulty of analysis. Data reported were the ∆Q at 5% threshold for each tooth on each of three attempts. Results Using ANOVA and paired t-tests to detect statistical differences, the three attempts of each examiner were used to determine intra-examiner reliability. Only one examiner (a novice at the technique) demonstrated differences between all three attempts and two demonstrated difference between one attempt. When the mean scores were compared to determine the inter-examiner reliability, only one examiner's results were statistically different when compared with two others. Conclusion This study has demonstrated that the analysis stage of QLF is reliable between examiners and within multiple attempts by the same examiner, when analysing in vitro lesions. Novices at the technique should be trained before analysing experimental data.

Performance of a fluorescence camera for detection of occlusal caries in vitro

“…The fl uorescence device showed good reproducibility whether it was operated by an experienced or less experienced investigator. Pretty et al 26 showed in a study using the QLF that an examiner novice to the technique demonstrated differences in intra-examiner reliability compared with other examiners with more training. They recommend that novices to the technique should be trained before they analyze experimental data.…”

Comparison of quantitative light-induced fluorescence (QLF) and digital imaging applied for the detection and quantification of staining and stain removal on teeth

“…20 It is reasonable to extrapolate this to stain assessments as the mechanism for stain detection is similar.…”

The use of in situ models and QLF for the study of coronal caries

“…21 Sixteen teeth with lesions of varying severity were analysed by 10 examiners on three occasions. Both intra-and inter-examiner agreement was good, with few significant differences in DQ being found.…”