# Limited radiographic detectability of novel 3D printed materials used in dental surgery

## TL;DR

Modern 3D-printed dental materials are hard to detect in X-ray scans, making them risky if they break during surgery.

## Contribution

This study quantifies the radiodetectability of 3D-printed dental materials in soft tissues using CT and CBCT.

## Key findings

- Modern 3D-printed dental materials have radiodensities similar to muscle tissue (68.94–130.47 HU).
- Small splinters of these materials are nearly invisible in CT and CBCT scans compared to conventional dental materials.
- Conventional materials like Futar D® and Luxatemp® show much higher radiopacity (up to 3243.96 HU).

## Abstract

The digitalization of numerous dental workflows has significantly expanded the possibilities of digital treatment planning in recent years. By using additively manufactured templates and guides, preoperative planning can be realized reliably and minimally invasively on the patient. However, these devices may break under mechanical stress during use, so that fragments may remain in the surgical field, be swallowed or aspirated. This study investigates the radiologic detectability of additively manufactured materials in surrounding soft tissue.

The visual detectability of standardized scan bodies and splinters of 15 different materials used in dentistry was analyzed using cone-beam computed tomography (CBCT). Porcine muscle and subcutaneous tissue were used as surrounding structures. In addition, computed tomography (CT) was used to measure the radiation densities of the materials in Hounsfield units to obtain quantitative reference values for the recognizability of the materials in comparison with soft tissues.

The radiodensities in CT images of all modern materials used in computer-aided manufacturing ranged from 68.94 ± 5.32 HU to 130.47 ± 4.52 HU and were thus very similar to those of muscle tissue. In CBCT images, large cylinders as well as small splinters of these materials were hardly visible in both subcutaneous fat and muscular tissues. Overall, the small splinters were more difficult to differentiate from the surrounding tissue than the larger cylinders. The conventional dental materials Futar D® and Luxatemp® exhibited significantly higher radiopacity at 1031.18 ± 12.97 HU and 3243.96 ± 69.03 HU.

The results of this study show that neither CT nor CBCT may currently not be suitable for visualising modern 3D-printed dental materials against surrounding soft tissue. This is due to the materials’ insufficient radiopacity, which prevents clear delineation. Classic materials for temporal direct restorations and silicones were much easier to detect than the tested additively manufactured materials.

The online version contains supplementary material available at 10.1186/s12903-025-07158-w.