Comparison of the accuracy of intraoral scanners, intraoral cameras, radiographs, and histological methods for the diagnosis of dental caries: a systematic review and meta-analysis

Objective: This systematic review and meta-analysis compare the diagnostic accuracy of intraoral scanners (IOS) and intraoral cameras (IOC) against traditional radiographic and histological methods for caries detection. Due to variation in sensitivity (SE) and specificity (SP) among diagnostic tools, this study evaluated their performance based on lesion type, lesion location, and examiner-dependent factors. Methods: A comprehensive literature search was conducted using keyword-based search strings in Scopus, Web of Science, PubMed, Cochrane Library, and Dentistry & Oral Sciences Source, following PRISMA-DTA guidelines. Studies comparing IOS or IOC to radiographic or histological reference standards were included. Three independent reviewers assessed study quality using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist, with disagreements resolved by discussion and Fleiss’s kappa (κ) analysis. Meta-analysis was performed using a bivariate random-effects model to estimate pooled SE and SP. Subgroup analyses examined the impact of lesion type, lesion location, and examiner-dependent variabilities, using the Python programming language. Results: Twenty-eight studies met the inclusion criteria, with 16 studies included in the meta-analysis. Pooled SE and SP of IOS and IOC were 50%, indicating moderate diagnostic accuracy. Radiographic methods had the highest SP, making them more effective at avoiding false positives. In contrast, IOSs and IOCs demonstrated higher SE for occlusal and dentin lesions, suggesting their utility in early caries detection. Lesion location significantly influenced diagnostic accuracy, with IOS and IOC showing superior SE for occlusal lesions but lower SE for supragingival lesions. Examiner-dependent differences in SE reached up to 32%, emphasizing the need for structured training and calibration protocols. Conclusions: IOSs and IOCs showed promise for early caries detection due to their higher SE for occlusal and dentin lesions. However, their lower SP compared to radiographic methods raises concerns about false positives. Standardized examiner training and improved diagnostic protocols are essential to enhance the reliability of these digital imaging techniques. © The Author(s) 2025.