When the dentist is faced with a mobile dental implant, a complete examination of the dental implant and its components should be undertaken. Mobility could be caused at different levels as follows.
Mobility at the fixture level
It is usually a case of failing osseointegration. It is also possible (but less likely) that there’s a fracture of the implant fixture.
Mobility at the abutment level
Abutment could become mobile if the abutment screw is loosened.
Mobility at the crown level
The crown component (prosthetic component) could become loose if it is decemented or the retention screw becomes loose.