ABSTRACT
Objective:
To make the
fixed partial dentures with different materials and the
magnetic resonance imaging (MRI)examination of
head and
neck was carried out to investigate the effects of
fixed partial dentures on MRI.
Methods:
A qualified
volunteer was recruited,
who was conventionally restored using
fixed partial denture. Co-Cr
alloy,Au-Pt
alloy and Zirconia were chosen as the inner
crown materials,respectively.Three kinds of
fixed partial dentures were put into the
mouth of
patient,and 2 kinds of
MRI scan sequences (T1-TSE and T2-TSE) were performed.The scanning images without restorations were used as controls.The change of shape,image signal and involving layers of
artifacts of different materials in three groups were observed.The maximum diameter of
artifact of three materials in coronal, sagittal and axial images were detected. The
safeties of
fixed partial dentures were observed.
Results:
The
artifacts were found in all the restorations and showed the changes of strengthen and weaken of the signal and the changs of shapes of images.The range of
artifacts was the largest in the involved central plane and varied in sagittal,coronal and axial images. The number of involving layers of
artifacts in Co-Cr
alloy group was significantly more than those in Au-Pt
alloy and Zirconia groups;the
artifacts were limited in the repaired lateral maxillofacial region without the
cervical spine and
head region involvement.The
artifacts in Co-Cr
alloy group involved or slightly involved in all adjacent
tissues,and the
artifacts in Au-Pt
alloy and Zirconia groups only slightly affected the mandibular
teeth,lingual
muscles and maxillary
crowns.The maximum diameter of
artifacts in Co-Cr
alloy group was larger than those in Au-Pt
alloy group and Zirconia group (P <0.05). No displacement was found in the
prosthesis,and the
patient had no discomfort.
Conclusion:
The
artifact of the
fixed partial denture can be seen in MRI examination.Co-Cr
alloy or zirconia can significantly reduce the effect of
artifact.Fixed
adhesive prosthesis in
mouth does not
affect the
safety of MRI examination.