Comparison of Laser Fluorescence and Longitudinal Microradiography for Quantitative Assessment of in vitro Enamel Caries

Abstract

A new quantitative, non-destructive method using laser-induced fluorescence (LAP) was compared with longitudinal microradiography (LMR) for assessment of mineral changes in enamel slices using an in vitro caries model. Ten enamel slices, cut longitudinally from sound natural smooth surfaces of human teeth, were exposed to de- and remineralization in a pH-cycling model. The enamel slices were subjected to LAF and LMR measurements before and at 2, 4, 7, and 9 days of demineralization. For LAF, the average fluorescence radiance decreased during the demineralization period with 11% by day 2 and 49% by day 9. For LMR, the corresponding average loss of mineral content changed with 0.01 and 0.10 kg m^––2 over the same time period. The mineral losses in each individual enamel slice measured with the two techniques were strongly correlated, r = 0.97. The Spearman rank correlation coefficient for all LAF and LMR demineralization results was 0.86. The precision (coefficient of variation) for LAF was 3.1%, corresponding to 0.005 kg m^––2, and the repeatability error for LMR was 0.02 kg m^-2 indicating a lower discrimination threshold for LAF compared to LMR. It was concluded that the new, sensitive, nondestructive LAF method provides possibilities for further improvement in the quantification of initial caries lesions in natural smooth enamel surfaces for use in in vitro studies. Furthermore, it offers potential in in situ caries studies as well as a tool in the diagnosis of early enamel caries in vivo.

Use of new minimum intervention dentistry technologies in caries management

“…[18][19][20][21] In brief, the QLF system's ability is to accurately determine mineral content of enamel.…”

Relationship between fluorescence loss of QLF and depth of demineralization in an enamel erosion model

“…The control group without demineralization was analyzed to record the baseline, while the lesion models were analyzed using QLF at the end of each demineralization period 3,11,22) . 2 ): ΔF integrated by lesion area in mm 2 5) .…”

“…Quantitative light-induced fluorescence (QLF) is a powerful tool which makes it possible to diagnose the degree of demineralization in a non-destructive way [3][4][5] . When a sound tooth surface is irradiated by blue-green light, it emits fluorescence with a wavelength of 540 nm.…”

White-Spot Lesions in Orthodontics: Incidence and Prevention

“…The use of QLF allows for quantitative analysis has been reported to be well correlated (0.73-0.83) with the degree of mineral loss from early enamel lesions in-vitro when measured by longitudinal microradiography. (Hafstrom-Bjorkman et al, 1992;Emami et al, 1996;Lagerweij et al, 1996). The use of QLF as a method of following caries development during orthodontic treatment has been suggested and encouraged by the results of several in-vitro studies.…”