While the structure and concept of digital-SLR cameras makes the complete elimination of these dust spots very difficult, it has come to our attention that, in some rare cases, they may be reflected noticeably in images. Therefore, Nikon is informing users of a service to reduce this issue.
Resolution
As a first step, please follow the guidance from the User’s Manual (pages 301-305) related to the “Clean Image Sensor” function and manual cleaning using a blower. If these measures do not remove all dust particles and you are still experiencing problems, then please consult your nearest Nikon service center. They will keep your camera, examine it thoroughly, and service it as needed.