A model study for quantification of approximal caries with a fluorescent dye.

Area of Science:

• Dentistry
• Biophotonics
• Materials Science

Background:

• Diagnosing early caries often requires invasive methods.
• Fluorescence-based techniques offer a promising non-invasive approach.
• Measuring fluorescence through overlying sound tissue is crucial for approximal caries detection.

Purpose of the Study:

• To evaluate the feasibility of measuring fluorescence intensity of Fluorol 7GA through scattering material.
• To establish a correlation between fluorescence intensity and mineral loss in artificial caries lesions.
• To develop a method for correcting fluorescence measurements for light scattering effects.

Main Methods:

• In vitro caries lesions were created and fluorescence intensity of Fluorol 7GA was measured through plastic strips (1.5 mm and 2 mm thick).
• Light scattering properties of plastic strips were compared to sound enamel.
• Longitudinal microradiography was used to quantify calcium loss.
• Light transmission at non-absorbing wavelengths was measured to correct fluorescence readings.

Main Results:

• Fluorescence intensity of Fluorol 7GA could be measured through scattering material, mimicking sound enamel.
• A strong linear correlation was found between fluorescence intensity and calcium loss (r=0.76 for 2mm, r=0.81 for 1.5mm).
• Measurements using a 1.5mm strip yielded approximately double the fluorescence intensity compared to a 2mm strip.
• A method for correcting fluorescence intensity using light transmission measurements was demonstrated.

Conclusions:

• Fluorescence measurements of caries lesions are feasible through overlying sound enamel.
• The proposed method shows potential for accurate, non-invasive clinical diagnosis of approximal caries.
• Correction for light scattering enhances the reliability of fluorescence-based caries detection.