Disturbing effect of different dental materials on the MRI results: preliminary study

The influence of different dental materials used for conserving reconstruction of teeth on the magnetic resonance imaging assessed on the basis of changes in NMR proton relaxation T1 of the physiological environment represented by the physiological salt solution has been studied. The dental materials studied varied in a wide range of chemical compositions: composites (Silux Plus made by 3M Dental, Tetric Cream made by Ivoclar-Vivadent), pH controlling composite (Ariston pHc made by Vivadent), hybrid glass ionomer (Vitremer made by 3M Dental), compomer (Hytac made by ESPE), amalgamate without the gamma phase (Septalloy made by Septodont), chemo-cured phosphate cement (Agatos made by Chema-Elektromet), phosphate cement with addition of silver (Argil made by Spora-Dental). The reference standard was a 0.9 % physiological solution of NaCl. The relative deviations of the spin-lattice relaxation time vary from –18.5 % to +24.0%. From the point of view of magnetic resonance imaging, the materials significantly disturbing the tomographic images are the amalgamate Septalloy-Septodont and glass ionomer Vitremer-3M Dental, while the composite Tetric Cream-Vivadent has insig-nificant effect. Key words: dental materials, MRI, spin-lattice, relaxation time