Abstract: Abstract: Objective To study the influence of two low noble metal alloys for dental restorations on MRI.Methods Anhydrite model for full crown preparation of low right second premolar was prepared.Porcelainfusedtometal （PFM）crown and ceramic crown were made from silverpalladium （AgPd）,goldpalladium （AuPd）,cobaltchrome （CoCr）and zirconia,with 8 samples for each type.The samples were subjected to magnetic resonance imaging （MRI）examination.The areas of MRI artifacts were measured and then analyzed with SPSS16.0 Statistic Software.Results Conspicuous artifacts were found in all the materials in GRE sequence,and crown structures could hardly be discriminated.In SE and TSE sequences,the artifact area in CoCr PFM crown was larger than that in AgPd and AuPd PFM crowns,and the difference was statistically significant.Besides,the difference of artifact areas between AgPd and AuPd PFM crowns demonstrated no statistical significance.Conclusions There are no conspicuous MRI artifacts of AgPd and AuPd PFM crowns in SE and TSE sequences,which is preferable in clinic.

Key words: [key words] magnetic resonance imaging, artifact, noble metal