Concerning the widespread use of X-rays to detect various diseases, such as oral and dental ones, it is essential to study the effects of this radiation on living cells. From the past, genetic effects and cell death because of X-rays have been studied. In addition, the effect of this ionizing radiation on the mechanical properties of the cell and cytoskeleton has been studied, but different results have been obtained based on different models. In this study, post-culture gingival fibroblast cells were classified into two groups of control and radiation with Nano Magnetic Particles functionalized by folic acid. The cells of the radiation group were exposed to X-rays of 3 mGy·cm2 . The specimens were undergone static creep test by a magnetic tweezer. Spring and damper coefficients were obtained based on the viscoelastic solid modeling. The static and dynamic stiffness of the groups was also calculated. The maximum deformation was decreased after radiation from 0.049 ± 0.01 µm to 0.029 ± 0.01 µm and the static stiffness of the model was 1.6 times decreased. Also, the gel point frequency for the control group was 27 Hz and for the radiation group was 7.5 Hz. The results show that the static and dynamic stiffness of the cells decreases after radiation, and less deformation appears in the cells after irradiation. These changes can be due to the breakdown of membrane chemical bonds and activation of actin fibers after radiation.