I did my exam with the Royal College of Radiographers, was told a lot easier to pass, and i did first time round. Recognised by the GDC, its just that the NEBDN one is known more coz its been there longer than the RCR one. Don't know if u can write exam in your area, I did mine in Aldershot, Hampshire (South West). Contact Southern Dental Trainers for more info, their number is 01252 319 638. Hope that helps and good luck!!