A scale and polish is a Band 1 treatment, even if more than one visit is required.
As with any Band 1 claim, an examination, and completion of any planned treatment, that the patient is willing to undergo, is a requirement.
A scale and polish would be appropriate for BPE (British Society of Periodontology) scores of 2, or for periodontal maintenance (as opposed to treatment) where periodontal disease is stabilised.