This could lead to serious problems that occur if clonidine is stopped suddenly. Previous versions of the prescribing information for clonidine tablets and patches stated that the medication was approved for use in children as young as 12 years old. The current prescribing information states that these medications are not approved for use in children.
Therefore whereas a dental x-ray room may require a. nominal shielding of about 1.5mm lead for the direct beam and. about 0.7mm lead for the scattered field, a diagnostic x-ray. room may require a nominal shielding of about 3mm and 1.5mm. for the direct beam and scattered field respectively.
Alpha and Beta Shielding. While density remains an important characteristic for blocking alpha and beta radiation, thickness is less of a concern. A single centimeter of plastic is sufficient for shielding against alpha particles, as is a half-inch of paper. In some cases, lead is ineffective in stopping beta particles because they can produce secondary radiation when passing through elements with a high atomic number and density.