Diagnostic Performance of Multispectral SWIR Transillumination and Reflectance Imaging for Caries Detection

Area of Science:

• Dental diagnostics
• Medical imaging technology
• Caries detection

Background:

• Conventional methods for caries detection, such as visual assessment and radiography, have limitations in sensitivity and specificity.
• Early detection of dental caries is crucial for effective treatment and prevention of tooth decay.
• Advanced imaging techniques are being explored to improve diagnostic accuracy in dentistry.

Purpose of the Study:

• To compare the diagnostic performance of dual short wavelength infrared (SWIR) imaging (transillumination and reflectance) with conventional methods for caries detection.
• To evaluate SWIR imaging for detecting caries on premolars scheduled for orthodontic extraction.
• To establish polarized light microscopy (PLM) and micro-computed tomography (microCT) as gold standards for comparison.

Main Methods:

• A custom-fabricated, 3D-printed imaging probe with a SWIR camera was used.
• Occlusal transillumination at 1300 nm and reflectance measurements at 1600 nm were performed in vivo on 135 premolars from 40 subjects.
• Teeth were subsequently extracted for analysis using PLM and microCT as gold standards.

Main Results:

• Near-simultaneous real-time transillumination and reflectance SWIR video acquisition for caries detection was demonstrated.
• Both SWIR imaging modalities exhibited significantly higher sensitivity for detecting proximal and occlusal caries compared to visual assessment and radiography.
• Reflectance imaging at 1600 nm showed higher sensitivity and specificity than transillumination at 1300 nm; combined SWIR methods improved specificity but reduced overall sensitivity.

Conclusions:

• Dual SWIR imaging offers a promising advancement in dental diagnostics for caries detection.
• SWIR imaging modalities, particularly reflectance at 1600 nm, outperform conventional methods in sensitivity and specificity.
• Further research into optimizing combined SWIR techniques may enhance diagnostic accuracy for early caries detection.