Detection of Primary Occlusal Caries With ICDAS, PTR/LUM and QLF

Objectives: Evaluate the performance of visual examination (International Caries Detection and Assessment System; ICDAS), Photothermal Radiometry and Modulated Luminescence, PTR/LUM, (The Canary System^®; Quantum Dental Technologies, Toronto, Canada), and two Quantitative Light-Induced Fluorescence devices (QLF Inspektor Pro and QLF-D Biluminator™ 2; Inspektor Research Systems B.V., Amsterdam, The Netherlands) on detection of occlusal primary caries in vitro by three different examiners.
Methods: Extracted human posterior teeth (N=60) with fully formed roots and no frank cavitations or restorations were selected from a pool of teeth (IU-IRB # 1302010696). A single site was selected on each occlusal surface to represent ICDAS scores “0” to “4”. Three calibrated examiners, guided by white-light images, assessed the sites independently using ICDAS, The Canary System^®, Inspektor Pro and QLF-D twice with a 5-7 days interval between examinations. Histological validation was used to compare methods in regards to sensitivity, specificity and the area under receiver operating characteristic curve (AUC). Examiners agreement and repeatability were measured using Intraclass Correlation Coefficients (ICC).
Results: Sensitivity, specificity and AUC values were respectively: 0.82, 0.86 and 0.87 (ICDAS); 0.85, 0.43 and 0.79 (The Canary System^®); 0.89, 0.60 and 0.90 (QLF Inspektor™ Pro); and 0.96, 0.57 and 0.94 (QLF-D). Intra-examiner repeatability range and inter-examiner agreement were respectively: 0.81-0.87: 0.72 and (ICDAS); 0.33-0.63: 0.48 (The Canary System^®); 0.49-0.97: 0.73 (Inspektor™ Pro); and 0.96-0.99: 0.96 (QLF-D Biluminator™ 2).
Conclusions: Visual examination using ICDAS criteria had the best combination of sensitivity, specificity and AUC for detection of early primary caries on occlusal surfaces. The Canary System^® had the lowest specificity and AUC values. QLF systems demonstrate a potential for longitudinal monitoring given its high sensitivity and AUC and repeatability.