The interaction and interference of preformed metal crowns on magnetic resonance imaging: a scoping review with a systematic methodology.

Preformed metal crowns are widely used to restore primary and permanent teeth. Children may require magnetic resonance imaging (MRI) for diagnosis and monitoring of diseases in the head and neck region. Metallic objects, in the field of view, may compromise the diagnostic value of an MRI. The impact on the diagnostic quality of an MRI in children who have had preformed metal crowns placed has not been assessed. The aim of this systematic review was to evaluate the impact that PFMCs have on MRI imaging quality and thus the overall diagnostic value. Electronic searches of the following databases were completed: MEDLINE, EMBASE, Cochrane Library, Web of Science and Open Grey. Primary in vivo studies on children who had at least one preformed metal crown placed and required an MRI investigation were to be included. PRISMA guidelines were followed and screening/data extraction was carried out by two independent calibrated reviewers. A total of 7665 articles were identified. After removing duplicates, 7062 were identified for title and abstract screening. Thirty-four articles underwent full-text review, of which none met the inclusion criteria. Most common reasons for exclusion were not placing preformed metal crowns (n = 16) or in vitro studies (n = 12). No in vivo studies were identified to establish the hypothetical impact preformed metal crowns would have on the diagnostic quality of an MRI in the head and neck region. Decision making needs to be guided on a case by case basis. Further high-quality clinical studies are required.