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Objective:To observe the influence of commonly used dental cast metal posts and cores on magnetic resonance imaging (MRI)for head and neck.Methods:Six kinds of posts and cores made of metal alloy (Ni-Cr alloy,Co-Cr alloy,titanium alloy,pure titanium,Pd-Au alloy and Au-Pt alloy)were respectively fixed on the mucosa of left palate of a volunteer.The maxillofacial region of the subjects was scanned by routine head sequences SE-T1WI and TSE-T2WI respectively.Results:ANOVA of factorial design analy-sis indicated significant differences of artifacts among metal materials(F=153.63,PCo-Cr alloy>Ni-Cr alloy>Au-Pt alloy>titanium alloy>pure titanium;two posts and cores>one post and core;SE-T1WI>TSE-T2WI.Conclusion:Different cast metal posts and cores have different influences on MRI artifact.Reasonably choosing the metal materials and scanning sequences can minimize artifacts on MRI.
RESUMO
BACKGROUND:The post and core system for residual roots and crowns can achieve satisfactory effects, when fil ing restoration, ful crowns or inlay has poor effects. OBJECTIVE:To evaluate the clinical use of glass fiber post and metal post in the restoration of endodontical y treated teeth. METHODS:A total of 106 patients with 160 endodontical y treated teeth were selected and restored with glass fiber post (n=80 teeth) and metal post (n=80 teeth) fol owed by porcelain-fused-mental crown. The restorations were evaluated clinical y for 9 to 33 months. RESULTS AND CONCLUSION:Glass fiber post treatment for 78 teeth was effective and that for two teeth were failed, with a successful rate of 98%. Metal post restoration was effective in 71 teeth and failed in nine teeth including one tooth of crown fracture, four of root fracture and four of post loss, with a successful rate of 89%. There was statistical y significant difference between two groups (P<0.05). Glass fiber post is better in convenient handling and good color and reduced probability leading to root broken for dental restoration compared with metal post.