If it's not long after it's been fitted, this must be considered as part of the aftercare and part of the original Course of Treatment (CoT).
You cannot charge the patient or claim any UDA.
If you feel the appliance was complete and it fit originally this would be covered under band 1 - Adjustments to and easing of Dentures or Orthodontic appliances.
Although the regulations do not mention a Bridge, this would still apply.