Today's sunday and my fixed dental bridge is moving where one abutment is. placed 2 years ago. could it be the tooth root is moving = extraction?

Could be: Tooth could also be fractured, or the cement may have washed away. Hard to say without visualization and a radiograph.

See your dentist: There are many various reasons which could cause fixed dental bridge to fail (e.g. oral hygiene, materials used, how often you visit the dentist, the technique of the dentist). I can appreciate your concerned about your dental health, but finding a proper diagnosis and treatment may be the answer to your worries. Rec.: see your dentist for examination and x-rays.

Possible fracture: It is possible that the tooth is fractured or the tooth has lost bone and the entire tooth is moving.

Get an exam & Xray!: Could be the tooth's moving but more likely the bridge has dislodged from the abutment or the abutment tooth is fractured. Get this checked soon before infection develops or the other abutment suffers some irreversible trauma. Hopefully, the bridge just needs to be recemented. Best option is to see the dentist who originally placed the bridge since that dentist will have the "before" xrays.

Contact your DDS: See your dentist and have the dentist radiograph the area for a definitive diagnosis. The variables include- need for recementation, decay,fracture or periodontal issues. It is premature to comment without all the information- see your dentist.