Comparative fluorescence spectroscopy of root caries lesions

Area of Science:

• Biophotonics
• Dental Research
• Spectroscopy

Background:

• Root caries is a significant dental issue affecting tooth structure.
• Understanding the optical properties of carious lesions can aid in diagnosis.
• Previous studies have explored fluorescence but not extensively across a wide excitation range for root caries.

Purpose of the Study:

• To investigate the light-emission properties of carious and sound root surfaces.
• To determine the fluorescence characteristics of light- and dark-discolored root caries.
• To identify optimal excitation wavelengths for detecting root caries via fluorescence.

Main Methods:

• Human molar teeth with light/dark root caries and sound surfaces were analyzed.
• Fluorescence spectrophotometry was used across excitation wavelengths from 360-580 nm.
• Emission and excitation spectra were recorded and normalized, with corrections for instrument variations.

Main Results:

• Carious root surfaces showed distinct fluorescence emission bands (600-700 nm) absent in sound surfaces.
• Maximum fluorescence intensity for root caries occurred at excitation wavelengths of 390-420 nm, peaking around 405 nm.
• Root caries spectra exhibited a red shift compared to sound surfaces, more pronounced in dark-discolored lesions.

Conclusions:

• Root caries possesses characteristic fluorescence signatures detectable by spectrophotometry.
• The excitation maximum at 405 nm suggests the involvement of porphyrin compounds.
• Fluorescence spectroscopy shows potential for differentiating carious from sound root surfaces and lesion severity.