Effect of 1.5-T and 3.0-T magnetic resonance imaging on the ceramic adhesion and physical properties of prosthetic substructures

Abstract

Statement of problemMagnetic resonance imaging (MRI) is a cross-sectional imaging technique that is widely used in the detection of pathologies in the head and neck region. However, information is lacking about the effect of MRI imaging on the clinical success of fixed partial dentures (FPDs). PurposeThe purpose of this in vitro study was to analyze the effect of MRI on the physical properties and ceramic adhesion of FPD substructure materials. Material and methodsThree hundred disk (12×1 mm) and 255 rectangular (4×2×2 mm) specimens were prepared with different fabrication techniques for 5 experimental groups: direct metal laser sintering (DMLS) with Co-Cr and Ti; casting with Co-Cr and Ni-Cr; and milling with ZrO2. After ceramic application, the disk specimens were subjected to aging and divided into 3 subgroups (n=20) with exposure to 1.5-T and 3.0-T MRI brain scans for 30 minutes and no exposure (control). The shear bond strength (SBS) of the specimens was measured by using a universal testing machine. The rectangular specimens were exposed to MRI with the same procedure, and the nanostructure of the specimens was analyzed with the small-angle X-ray scattering (SAXS) method to detect the nanoscale structural effects of MRI. The average surface roughness (Ra) and Vickers microhardness (Vh) were also measured for complementary analyses. SBS, Ra, and Vh values were statistically analyzed by 1-way ANOVA and the Tukey honestly significant difference test (α=.05). ResultsThe SBS (MPa) of casting groups (P<.001) and DMLS with the Co-Cr group (P<.05) were significantly affected by MRI exposures. The significant differences were seen on the Ra of casting (P<.001) and DMLS with Co-Cr (P<.05) and Ti (P<.01) groups. Also, the Vh of the casting with Co-Cr (P<.001) and Ni-Cr (P<.01) groups showed significant differences. The SAXS analysis indicated that the physical properties of materials were influenced by MRI exposure. ConclusionsThe results indicated that MRI applications affected the metal-ceramic adhesion of Co-Cr and Ni-Cr dental alloys produced by casting and the DMLS technique.