I am currently scoping the refurbishment of a large dental practice, I am wondering if a patient undergoing an unconscious procedure would be considered a sleeping risk, because if not I can remove the fire rating from most of the treatment room doors

If it's conscious sedation which is usually the main procedure that is carried out by dentists that requires more than local anaesthetic and the nearest you would get to unconscious outside an operating theatre they will not be asleep (other than possibly very brief periods) but would some need assistance in evacuation as they will be drowsy and relaxed with a lower blood pressure (that could lead to fainting if got up too quickly).Technically speaking they aren't asleep in bed, but additional protection may be needed as either PHE or delayed evacuation may be appropriate.

Many practices have stopped doing CS and those that do usually have a dedicated room for it due to the extra equipment and space required - this also limits the need for extra sub compartment provision to one room/section of the practice.