The influence of preformed metal crowns versus zirconia crowns on the diagnostic quality of magnetic resonance images

The purpose of this study was to investigate and compare in vitro the influence of preformed metal crowns (PMC) versus zirconia crowns (ZC) on the extent of artifact formation and the diagnostic quality of magnetic resonance imaging (MRI).

Standard crown tooth preparations were performed on Typodont models. PMC and ZC were cemented on all primary molar teeth (n = 8) of the respective models. MRI scans were taken for the Typodont alone (control), PMC, and ZC, using a 3 T MRI machine and common MRI sequences. The diameter of image distortion was measured around the dental materials. Data was analyzed using a mixed model analysis.

The average artifact size for PMC was 54.9 mm (range 19.6–110.7 mm) and 12.8 mm (range 5.5–20.7 mm) for ZC. The artifact size was associated with the MRI pulse sequence and dental material, with PMC showing larger artifact diameters than ZC for all MRI sequences (p < 0.001). The control had sensitive sequences for AxT2* and DWI sequences with MRI artifacts of 11.4 mm and 10.7 mm, respectively.

It is important that dentists are aware of the potential of dental materials to cause unfavourable MRI artifacts. When areas of the brain requiring MRI preclude the use of PMC, ZC may be considered as an alternative to extractions. Further clinical studies are required to evaluate the impact of dental materials on the image quality of MR scans in vivo.