Micro-abrasion is part of a treatment process, so it is not regarded as definitive treatment in its own right and no separate band applies when the technique is used.
For example, a child patient with fluorosis may have enamel micro-abrasion as part of an NHS Course of Treatment (CoT).
If a patient has enamel micro-abrasion as part of an NHS CoT then the band charge would depend upon the overall treatment provided.