The Caries Assessment Spectrum and Treatment (CAST) instrument: construct validation

Area of Science:

• Dentistry
• Epidemiology
• Diagnostic Accuracy Studies

Background:

• The Caries Assessment Spectrum and Treatment (CAST) is a novel epidemiological instrument for caries assessment.
• Validating new diagnostic tools is crucial for accurate epidemiological studies and clinical decision-making.

Purpose of the Study:

• To investigate the construct validity of the Caries Assessment Spectrum and Treatment (CAST) instrument.
• To compare the diagnostic performance of CAST against established gold standards in caries assessment.

Main Methods:

• Four calibrated examiners visually assessed 109 teeth using CAST codes (0-6).
• Teeth were hemisectioned and assessed histologically using Downer criteria.
• A subset of teeth underwent micro-computed tomography (micro-CT) scanning for assessment.
• Sensitivity, specificity, and Youden index were calculated comparing visual CAST assessment with histology and micro-CT.

Main Results:

• High inter-examiner consistency was observed: κ = 0.76 (visual-histology) and κ = 0.89 (visual-micro-CT).
• For 'healthy' vs. 'diseased' lesions, CAST achieved high sensitivity (up to 100%) and specificity (up to 92.9%) with micro-CT.
• For 'dentine' vs. 'non-dentine' lesions, CAST demonstrated high sensitivity (up to 90%) and specificity (100%) with micro-CT.

Conclusions:

• The study provides strong evidence for the construct validity of the Caries Assessment Spectrum and Treatment (CAST) instrument.
• CAST demonstrates good diagnostic accuracy when validated against histological and micro-CT assessments.
• The CAST instrument is a reliable tool for epidemiological studies of dental caries.