Plans break in the middle. A patient who accepted six appointments and attended three has not finished and has not said so, and nobody notices unless something tracks where each plan actually stopped.
The failed appointment is the clinic's most expensive routine event. An hour of surgery time lost at short notice cannot be resold, which makes reminders and a stated policy worth far more than they cost.
The hygienist is a separate business inside the practice. A different diary, different intervals and different recall rhythm: managed as an afterthought, those slots run half empty while the dentists are overbooked.
Estimates and consent belong before the work. A written treatment plan with costs, accepted and dated, prevents both the argument about the bill and the more serious argument about what was agreed.