Effect of Radiation Dose on Cell Dynamics

When cells with high mitotic activity are exposed to high-dose radiation, mitotic activity experiences a severe delay for an extended period before gradually returning to normal. In contrast, exposure to moderate doses of radiation causes a moderate delay in mitotic activity for a limited duration, followed by a temporary moderate increase before the mitotic rate returns to its normal level. (Figure 4).^2,6,8

Figure 4. Change of mitotic rate as a function of dose and time.

Figure 4. Change of mitotic rate as a function of dose and time.

Exposure of cells with high mitotic activity to low dose radiation would result in an initial mild delay in mitotic activity followed by a short period of increased mitosis before the mitotic rate would return to normal.^2,6,8 In association with dental radiography, neither short-term nor long-term effects of radiation on mitotic activity are discernable. ^2,5-7,11 However, to minimize exposure and maximize diagnostic yield, follow the dictum of ALARA - As Low As Reasonably Achievable.