MicroCT X-ray profile of dental biomaterials as a tool for identification in forensic odontology

This study evaluates the potential of X-ray micro-computed tomography (micro-CT) to characterize the radiological signatures of dental biomaterials and to support forensic human identification. Dental restorations are frequently used in forensic odontology due to their resistance to post-mortem degradation; however, the detection and discrimination of tooth-colored materials could remain challenging. A total of 26 extracted permanent teeth were restored with eight commonly used biomaterials, including resin composites, resin-modified glass ionomer, ceramics, polymethyl methacrylate, and temporary cements. All samples were scanned using high-resolution micro-CT, and grayscale profiles were extracted from enamel, dentin, and each restorative material. Gray values were normalized using hydroxyapatite phantoms to enable inter-scan comparison. Each biomaterial demonstrated a distinct and reproducible radiological signature, with grayscale levels varying significantly according to composition. Zirconia-based ceramics presented the highest radiopacity, whereas lithium disilicate ceramics showed values closer to natural enamel. Linear regression models confirmed a strong correlation (R² = 0.997-1.000) between grayscale level and physical density for reference phantoms; however, notable deviations were observed in biomaterials, underscoring the influence of atomic number and X-ray attenuation beyond density alone. These findings demonstrate that micro-CT enables non-destructive and quantitative differentiation of restorative materials based on their radiological profiles, offering a promising complementary tool for forensic odontology, particularly when ante-mortem dental records are incomplete or conventional imaging is insufficient. Future work should assess the stability of these radiological fingerprints under varied post-mortem conditions and explore their integration into automated identification systems and forensic reference databases.