If abutment screw is loose in dental implant, will it show up in the X-ray?

HI:Most likely it will not show up on the X-ray.  However, if the crown is loose but the implant is ok on the implant most likely it is the abutment screw.Best,Dr. Maddahi

Yes, if a screw is loose it would be noticeable in an x-ray. I suggest calling your dentist and having them take a look to avoid any issues that may arise from a loose screw.

If this is the case then something should show up.  Unfortunately, there is always the possibility of everything looking normal on the x-ray.  If the screw is easily accessible, then it can be accessed and checked for tightening as needed without too much fuss.