Can I repair an orthodontic appliance that was fitted by another performer?

Yes, providing that the practice you work at has an orthodontic component to it's contract.

The patient must have an assessment first, if the assessment indicates that the patient needs the repair, then you'll need to complete the FP17O as a charge exempt item.

The ‘Date of Assessment’ and ‘Date Appliance Fitted’ should be listed in Part 5 (Orthodontic Assessment and Treatment Start) of the FP17O.
 
Part 6 (Orthodontic Completion) Box 9 (Repair to appliance fitted by another dentist) must be ticked.