This study aims to evaluate and compare the diagnostic accuracy of visual examination using ICDAS-II and three adjunctive optical methods-laser fluorescence (LF), near-infrared light transillumination (NILT), and quantitative light-induced fluorescence (QLF)-for the detection of non-cavitated occlusal caries lesions in children. A total of 51 children aged 6-14 years, including 320 posterior teeth, will be examined under standardized clinical conditions. Diagnostic performance will be assessed using sensitivity, specificity, accuracy, and area under the curve (AUC) values. The findings are expected to support the use of adjunctive diagnostic methods for early detection and minimally invasive management of occlusal caries.

This in vivo observational study was conducted to evaluate and compare the diagnostic performance of visual examination based on the International Caries Detection and Assessment System II (ICDAS-II) and three adjunctive optical methods-laser fluorescence (LF), near-infrared light transillumination (NILT), and quantitative light-induced fluorescence (QLF)-for the detection of non-cavitated occlusal caries lesions in posterior teeth of children.

The study included 51 children aged between 6 and 14 years, comprising a total of 320 posterior teeth (104 molars and 216 premolars) with sound or non-cavitated occlusal surfaces (ICDAS scores 0-2). All examinations were performed under standardized clinical conditions using calibrated examiners. Visual assessment was conducted according to ICDAS-II criteria, and optical evaluations were performed using DIAGNOdent pen (LF), DIAGNOcam (NILT), and Qraypen C (QLF).

QLF analysis included the calculation of fluorescence loss (ΔF), lesion area, and integrated fluorescence loss (ΔQ) using a predefined threshold. Diagnostic performance of each method was evaluated using sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC), with ICDAS-II serving as the reference standard. Inter-examiner agreement was assessed using kappa statistics.

The study aims to determine the comparative effectiveness of these diagnostic methods in detecting early occlusal caries and to provide clinically relevant evidence for improving diagnostic accuracy and supporting minimally invasive treatment strategies in pediatric dentistry.

Inclusion Criteria:

• Voluntary agreement to participate in the study after the research procedures have been explained.
• Being between 6 and 14 years of age.
• Presence of at least one posterior tooth that is either sound with an ICDAS score of 0 or exhibits a non-cavitated occlusal carious lesion classified as ICDAS scores 1 or 2.
• Having an occlusal surface suitable for standardized clinical and optical evaluation using Diagnodent Pen, Diagnocam, and QLF devices.
• Absence of excessive plaque accumulation on the tooth surface to allow reliable measurements.

Exclusion Criteria:

• Declining participation in the study.
• Being younger than 6 years or older than 14 years.
• Presence of cavitated carious lesions (ICDAS ≥ 3) or teeth with Class II or Class III carious involvement.
• Prior restorative treatment or the presence of fissure sealants on the relevant occlusal surface, which would compromise accurate optical assessment.
• Tooth surfaces with excessive plaque accumulation that would hinder proper evaluation.

Children aged 6-14 years attending the Department of Pediatric Dentistry, Marmara University, were recruited for this study. The study population included participants with at least one posterior tooth exhibiting either sound occlusal surfaces or non-cavitated occlusal caries lesions (ICDAS scores 0-2). All examinations were performed under standardized clinical conditions.

De-identified individual participant data (including intraoral photographs and clinical evaluation scores) will be made available upon reasonable request to the corresponding author, for scientific research purposes, following approval by the relevant ethics committee.

De-identified individual participant data (IPD), along with supporting documents such as the study protocol and statistical analysis plan, will be available beginning 6 months after publication of the primary study results and will remain available for 5 years thereafter.

Requests for access to de-identified individual participant data and supporting documents will be considered for academic or scientific research purposes. Interested researchers must submit a written proposal detailing the planned analysis, including objectives and statistical methods. Requests will be reviewed by the principal investigator and institutional review board (IRB) representatives to ensure ethical compliance and scientific merit. A data use agreement must be signed prior to data release. Requests can be submitted via email to the corresponding author listed in the publication.