<prompt> All of the following materials are radiopaque in nature except:Zinc phosphateCompositeGutta perchaAmalgam  <response>: All given options are metallic radiopaque in nature except composite resins.Generally, non-metallic radiopaque markers gutta-percha, composite resin are used in MDCT imaging and CBCT imaging studies to minimize the effect of image artifacts produced by metal markers. Reference: White and Pharoahs Oral Radiology Principles and Interpretation 7th edition page no 637 