Background <p>To reveal the radiodensity and sonographic characteristics of various foreign bodies and dental materials to aid in the diagnosis of these materials.</p> Methods <p>The study included 41 objects consisting of various foreign bodies and dental materials. The objects were examined by embedding them in bovine gelatin, an in vitro environment and their radiodensity was evaluated using cone-beam computed tomography (CBCT). Additionally, their visibility and posterior acoustic behaviors were examined using ultrasonography (USG).</p> Results <p>When the radiodensity of the objects was examined in CBCT images, 27 objects (65.9%) were found to be hyperdense, while 14 objects (34.1%) were identified as isodense. All foreign bodies and dental materials included in the study were successfully visualized using USG. When the acoustic behaviors of the objects were examined, it was found that 24 materials (58.5%) caused posterior acoustic shadowing on USG. While no artifacts were detected in eight materials (19.5%), comet tail artifacts were observed in seven materials (17%), and reverberation artifacts were seen in two materials (5%).</p> Conclusions <p>CBCT is an important technique for imaging foreign bodies and dental materials. Nonetheless, in an in vitro environment, USG can visualize objects that cannot be seen with CBCT. These findings may assist clinicians in selecting the most appropriate imaging method for identifying accidentally ingested or embedded foreign bodies and dental materials, especially in emergency or surgical settings.</p> Trial registration <p>We would like to clarify that our study is an in vivo experiment that does not involve human participants. Therefore, it does not fall within the scope of clinical trial registration requirements under current international guidelines.</p>