•Visualization with QLF technology is a useful supplementary diagnostic technique.•The patient's age and the ∣ΔF∣ and ΔR values were positively correlated.
This retrospective study evaluated the ...clinical efficacy of quantitative light-induced fluorescence (QLF) technology for crack detection and the diagnosis of cracked teeth and assessed the possibility of a quantitative evaluation of cracks using QLF technology.
Patients who were clinically diagnosed with cracked teeth over a 1-year period were included. The QLF images of the corresponding symptomatic cracked teeth and asymptomatic contralateral teeth with crack lines were taken with Qraypen C (AIOBIO, Seoul, Korea). Fluorescence loss (ΔF), maximum fluorescence loss (ΔFmax), red fluorescence (ΔR), and maximum red fluorescence (ΔRmax) of the crack line were analyzed. The correlation between these parameters and sex, age, tooth position (1st premolar, 2nd premolar, 1st molar, 2nd molar), spontaneous pain (+/-), percussion test (+/-), cold test (++/+/-), and bite test (+/-) were statistically analyzed.
A total of 66 patients were included. Twenty-four patients had asymptomatic contralateral teeth with apparent crack lines; thus, 90 teeth were analyzed. The crack lines in 84 teeth observed as red fluorescent lines on the QLF images showed ΔR values higher than the cut-off value set by the analysis program used. The patient's age and the ∣ΔF∣ and ΔR values were positively correlated. However, there was no statistically significant difference in the QLF parameters between the same patient's symptomatic tooth and the contralateral tooth.
QLF technology is a useful assistive diagnostic device for diagnosing cracked teeth.
Orthodontic treatment with fixed appliances increases the caries risk in young persons. The aim of this study was to apply a new caries diagnostic method, quantitative laser fluorescence, for ...longitudinal in vivo quantification of changes in incipient enamel lesions related to fixed orthodontic appliances. Seven young patients with active caries lesions disclosed at removal of the orthodontic brackets and bands were enrolled in the study. Caries preventive measures were intensified, including dietary advice, oral hygiene instructions, and the regular use of a fluoride dentifrice. The caries lesions were monitored with the quantitative laser fluorescence method after removal of the brackets and once a month thereafter. For each lesion, three quantities were measured: lesion area (mm
2), mean fluorescence loss (%) over the lesion, and maximum loss of fluorescence (%) in the lesion. During a 1-year follow-up period, the areas of the lesions decreased and the enamel fluorescence lost was partly regained indicating that a remineralization process had occurred. It was concluded that quantitative laser fluorescence seems suitable for in vivo monitoring of mineral changes in incipient enamel lesions, and useful for the evaluation of preventive measures in caries prone persons, such as orthodontic patients. (Am J Orthod Dentofacial Orthop 1998;113:595-602)
Highlights • The usefulness of combining a QLF-D system for detecting restorations was confirmed by the restoration detection accuracy of the subjects improving significantly. • Inexperienced ...subjects who are unfamiliar with dental inspections may exhibit an improved educational effect.
The quantitative light-induced fluorescence (QLF) method is based on the natural fluorescence of teeth. Currently, the method is predominantly used in vitro and in clinical studies for early ...detection of carious lesions and for monitoring of de- and remineralization of white spots by quantifying the mineral loss and the size of smooth surface lesions. The objective of this paper was to demonstrate the potential of QLF for application in routine dental care. Experience with QLF was reported by selected cases, which enlightened the advantages of the method for caries detection and for evaluation of preventive interventions in caries-prone patients in daily practice.
Quantitative light-induced fluorescence (QLF) is based on the dark appearance of a white spot in otherwise highly fluorescent enamel. This can be explained by the increased scattering coefficient in ...the white spot compared with that of sound enamel. The aim of this study was to estimate the effect of different sound enamel scattering coefficients (s(SE)) and enamel thickness d, caused by developmental enamel differences, on the fluorescence appearance of white-spot lesions. We ran a Monte Carlo simulation of a 4 x 4 mm(2) illuminated enamel slab on a highly fluorescent background. The slab had a 0.7 x 0.7 mm(2), 100-microm-deep, white spot in the center. Fluorescent and back-scattered photons re-emitted from the central 2 x 2 mm(2) were recorded. We found that the fluorescence photon excitance from the white spot (F(WS)) was less than that of sound enamel (F(SE)), with an optimum difference for S(SE) between 20 and 80/mm. For s(SE) <20/mm, both F(SE) and F(WS) decreased with d. We found no relation with d for s(SE) >20/mm. The results indicate that for small s(SE), we are suffering from edge losses, which explains why the optimum for lesion visibility is not found at s(SE) = 0/mm, as would be expected.
The laser fluorescence method (LAF) was validated with longitudinal microradiography (LMR) for assessment of mineral loss in incipient caries lesions in human enamel. Fluorescence radiance scans and ...LMR recordings were made of 36 enamel slabs with incipient lesions. Original sound values for fluorescence radiance and enamel amount (kg.m-2) at the lesion site were reconstructed by a computer algorithm. Changes in fluorescence radiance and amount of enamel in each measuring point were calculated. The reconstruction method was tested on 20 sound enamel surfaces. The differences between measured and reconstructed values were -0.13 +/- 0.17% with LAF and 0.002 +/- 0.005 kg.m-2 with LMR. The repeatability of the caries quantification was tested by measuring one lesion 20 times. The fluorescence loss in this lesion was 18.2 +/- 1.0%. The enamel loss was 0.09 +/- 0.02 kg.m-2. The correlation between measurements with the two methods was r = 0.73. The non-destructive laser fluorescence method was concluded to be a sensitive and valid method for quantification of mineral loss in enamel caries lesions.
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