Comparing Images from Near-Infrared Light Reflection and Bitewing Radiography to Detect Proximal Caries in Primary Teeth

Objectives: The present prospective study aimed to compare near-infrared light reflection (NIRI) and bitewing radiographs (BWR) images to detect proximal caries in primary teeth. Methods: 71 children underwent routine BWR, and scans were performed using an intra-oral scanner (iTero Element 5D, Align Technology, Tempe, AZ, USA), including a near-infrared light source (850 nm) and sensor. Five specialist pediatric dentists examined the NIRI and BWR images. Results: The average participant age was 7.8 years. A total of 1004 proximal surfaces of primary molars and canines were examined, 209 carious lesions were detected on BWR, and 227 on NIRI. Comparison between all carious lesions detected on BWR and NIRI: Sensitivity (53.6%); Specificity (85.5%); Positive Predictive Value (PPV) (49.3%); Negative Predictive Value (NPV) (87.5%). Comparison between carious lesions involving the DEJ detected on BWR and at any level in NIRI: Sensitivity (61%); Specificity (83.4%), PPV (36.6%); NPV (93.2%). Comparison between enamel-only carious lesions detected on BWR and all lesions detected using NIRI: Sensitivity (44.8%); Specificity (85.5%); PPV (20.7%); NPV (94.8%). Conclusions: No additional diagnostic information can be gleaned from BWR if initial caries lesions in the enamel are not detected by clinical examination or in images from a NIRI scanner, making BWR unnecessary.