| |
This study aimed to evaluate QLF measurements of a group of artificial caries lesions at two centres using different versions of the QLF machine and analysis program. Twenty artificial white-spot lesions were created in extracted premolar teeth using a demineralising solution. Lesions were air-dried for 30 min prior to imaging. Images were made of lesions on three occasions in random order by the same operator (AJH) at Glasgow and at Liverpool. Both centres used a filtered Xenon light source. In Glasgow, the image illumination and collection device was a prism next to a CCD camera whereas, in Liverpool, the illumination and CCD sensor were arranged co-axially. Images were analysed using software from the host centre. In addition, images from Liverpool were also analysed using Glasgow software. The software in Glasgow was QLF version 1.97i, whereas in Liverpool QLF version 2.0 was used. Subjectively images of lesions made in Liverpool were of higher intensity and greater clarity than images made in Glasgow. ANOVA demonstrated no differences between analysis of the lesions at difference centres for the QLF measurements of Area (p = 0.16), maximum fluorescence loss (p = 0.36) or average fluorescence loss (p = 0.9). Initial analysis of the data demonstrated that the same operator may use QLF to make measurements of lesions using two different machines and two versions of the QLF analysis program. Supported by Inspektor Research Systems BV, Amsterdam and the Borrow Milk Foundation. |