NHS charges are based on the course of treatment required rather than the number of appointments involved. You normally pay the charge for the highest treatment band included in that course, unless you qualify for free NHS dental treatment or help with health costs.
Band 1 covers examination, diagnosis and preventive care. Band 2 adds treatments such as fillings, root canal treatment and extractions, while Band 3 covers more complex restorative care such as crowns, bridges and dentures. Urgent NHS care has its own charge.