Development of a Fluorescence-Based Caries Scoring System for an Intraoral Scanner: An in vitro Study

Area of Science:

• Dental Diagnostics
• Biophotonics
• Medical Imaging

Background:

• Accurate dental caries detection is crucial for effective treatment planning and patient outcomes.
• Current caries detection methods, including visual-tactile and radiographic assessments, have limitations in sensitivity and specificity.
• Intraoral scanners offer advanced 3D imaging capabilities that can be leveraged for novel diagnostic applications.

Purpose of the Study:

• To develop an automated fluorescence-based caries scoring system integrated with a 3D intraoral scanner prototype.
• To evaluate the diagnostic performance of this novel system against established caries detection methods.

Main Methods:

• A prototype intraoral scanner emitting 415 nm light was used to scan 73 permanent posterior teeth.
• Fluorescence signals (red and green components) were extracted from 139 occlusal examination sites and mapped onto 3D models.
• Four mathematical functions were derived for caries scoring, and the system's performance was compared to visual-tactile (ICDAS), radiographic (ICDAS), and histological assessments.

Main Results:

• The fluorescence-based system demonstrated strong correlations with histological assessments (rs = 0.78).
• The caries classification function, quantifying fluorescence compared to sound surfaces, achieved the highest intra-examiner reliability (κ = 0.964) and sensitivity-specificity sum (1.60-1.84).
• Performance was comparable or superior to visual-tactile and radiographic methods across different histological levels, with radiography excelling only in outer dentin lesions.

Conclusions:

• An automated fluorescence-based caries scoring system for intraoral scanners shows promising diagnostic performance.
• This system has the potential to enhance objective caries detection, improve oral examination efficiency, and support reliable monitoring of early caries lesions.