In vivo MRI‐based dental impression using an intraoral RF receiver coil

The MRI‐based contrast‐enhanced method of tooth surface digitization provides an alternative possibility for making a dental impression. It has recently been demonstrated that tooth surface digitization with an accuracy sufficient for production of dental restorations is possible using a clinical whole‐body MRI scanner. However, for an in vivo application of the technique, the required high nominal resolution and signal‐to‐noise ratio have to be achieved within reasonable measurement times. Existing radio frequency (RF) volume and surface coils have not been able to fulfill this requirement. The objective of this work was to develop a dedicated RF receiver coil for contrast‐enhanced dental MRI which provides a high sensitivity in the region of the whole dental arch and allows for application of the contrast media into the mouth of the patient. To achieve this goal, an intraoral dental coil design with a built‐in contrast medium applicator was developed and implemented. The coil was shown to enable high‐resolution contrast‐enhanced dental MRI in vivo. This was demonstrated on four teeth prepared for dental restorations. The average accuracy obtained for all four teeth was below 100 μm. For two of the teeth, copings were modeled based on MRI data and produced from zirconium oxide using computer‐aided design and manufacturing (CAD/CAM) technology.