Ability of quantitative light-induced fluorescence (QLF) to assess the activity of white spot lesions during dehydration

Masatoshi Ando, George K. Stookey, Domenick T. Zero

Research output: Contribution to journalArticle

19 Scopus citations


Purpose: To determine the ability of QLF to assess the activity of white spots using visual examination (VE) as the gold standard. Methods: Thirty-four specimens were prepared from extracted human permanent posterior teeth presenting natural white spots on the approximal surface. Fluorescence images were acquired at 1-second intervals for the first 10 seconds and every 5 seconds thereafter to 45 seconds. During image acquisition, specimens were dehydrated with compressed air. QLF variables of fluorescence loss (ΔF [%]), lesion size (S [mm2]), and ΔQ (ΔF×S [%×mm 2]), were determined. Change in QLF variables per second (ΔQLFD: ΔFD, ΔSD, ΔQD) was determined using the following equation: (subsequent QLF-variables - baseline QLF-variables)/dehydration time. Five experienced dentists independently conducted VE under standardized conditions using a dental unit's light, compressed air, with an explorer, used only to check surface structure. Prior to VE, examiners had participated in a half-day training seminar on VE. After drying the specimens, examiners graded the lesions according to dullness of surface, roughness and presence of microcavitation. Agreement by at least three of them determined the activity status of lesions. Results: ΔQLFD values of Active white spot group (n=7) were compared with those of Inactive white spot group (n=27) using a two-sample t-test. In general, the active group presented larger values of ΔQLF D than the inactive group; however, there were no differences in ΔFD and ΔSD. There were significant differences in ΔQD up to 6 seconds of dehydration (P < 0.05), and no differences after 7 seconds. The results suggest that ΔQD can differentiate between active and inactive white spot lesions using QLF during the first few seconds of dehydration.

Original languageEnglish (US)
Pages (from-to)15-18
Number of pages4
JournalAmerican Journal of Dentistry
Issue number1
StatePublished - Feb 1 2006

ASJC Scopus subject areas

  • Dentistry(all)

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