The validation of quantitative light-induced fluorescence to quantify acid erosion of human enamel.
OBJECTIVE
The purpose of this study was to validate the Quantitative light-induced fluorescence (QLF) device against transverse microradiography (TMR) with regard to the quantification of enamel erosion in vitro.


METHODS
Longitudinal in vitro.


METHODS
Thirty previously extracted, caries free, human premolars were selected and prepared by gentle pumicing and coating in an acid-resistant nail-varnish save for an exposed window on the buccal surface. QLF baseline images were taken and the teeth then exposed to an erosive solution, 0.1% citric acid (pH 2.74). Teeth were removed at 30min intervals, air-dried and QLF images taken. At this time one tooth was randomly selected, removed from solution and sectioned through the lesion at three sites. The polished sample (100microm) was subjected to TMR and analysed for erosive mineral loss using proprietary software, with the DeltaZ values noted. QLF images were analysed by a blinded examiner with DeltaF and DeltaQ values recorded. Data were entered into SPSS and the correlation between the DeltaZ and DeltaF, and DeltaZ and DeltaQ values calculated.


RESULTS
A wide range of erosive lesions was produced, with a steady increase in both DeltaZ and DeltaF over time; DeltaZ (24.0 (S.D. 1.2)-6114.3 (S.D. 1177.57)); DeltaF (1.8-11.2), DeltaQ (2.5-202.6). The results were scatter plotted and a regression line calculated. A positive correlation between DeltaZ and DeltaF of 0.91 was found, and for DeltaZ and DeltaQ; 0.87.


CONCLUSIONS
The ability for QLF to detect and longitudinally monitor in vitro erosion has been shown. The strong positive correlation of DeltaF with DeltaZ suggests that percentage fluorescence loss as measured by QLF could be of great value in the development of a non-destructive, longitudinal tool for use in vitro, in situ and possibly in vivo.
Pretty
I A
IA
Unit of Prosthodontics, Department of Restorative Dentistry, Turner Dental School, The University of Manchester, Higher Cambridge Street, Manchester M15 6FH, UK. iain.pretty@man.ac.uk
Edgar
W M
WM
Higham
S M
SM
D000143:Acids / Q000378:metabolism; D001641:Bicuspid; D003743:Dental Enamel; D005453:Fluorescence; D006801:Humans; D008027:Light; D008137:Longitudinal Studies; D008852:Microradiography / Q000592:standards; D012016:Reference Values; D012680:Sensitivity and Specificity; D014077:Tooth Erosion / Q000175:diagnosis*
D000143:Acids