Yeah, my dental hygienist - and my quick search tells me what she said is likely not true. There is something to radiation backscatter, but I couldn't find anything that showed radiation in aprons to be an issue. There was plenty about how improper storage, folding, loose stitching are issues, and the aprons do have a suggested expiration/replacement date... but the science may not be on her side when it comes to radiation transferring to the apron material itself.