Artifacts in magnetic resonance imaging of the head and neck: Unwanted effects caused by implant-supported restorations fabricated with different alloys.

STATEMENT OF PROBLEM: Implant-supported restorations may cause artifacts in magnetic resonance imaging (MRI) of the head and neck area. However, the effect of different alloys remains unclear.

PURPOSE: The purpose of this in vitro study was to assess artifacts in head and neck MRI caused by implant-supported restorations with different alloys.

MATERIAL AND

METHODS

Three dry mandibles were prepared to receive bilateral dental implants at the second premolar and second molar sites. Different alloy combinations were evaluated: titanium implants+cobalt chromium restorations; titanium-zirconium implants+cobalt chromium restorations; and zirconia implants+ceramic restorations. Specimens were imaged by using a 3-Tesla magnetic resonance scanner system (Achieva 3.0T TX; Philips GmbH) with a turbo-spin-echo sequence. Scan protocols were adjusted to optimize metal artifact reduction and shorten scan time. Artifact volumes were assessed and statistically analyzed by using the Kruskal-Wallis and Spearman tests (α=.05).

RESULTS

A statistically significant difference was found among artifact volume caused by different materials (P=.002). The presence of titanium alloy was correlated with the artifact volume (r=-.87). Artifacts were greater for titanium and fewer for titanium-zirconium alloys, whereas zirconia implants found only minimal artifacts.

CONCLUSIONS

The dimension of artifacts produced by implant-supported restorations varied according to the material.