In the commercial sense people “buy” dentistry. However, from the point of view of being a health care provider, the last thing that you want to be seen as doing is “selling” the services you provide.
Patients should never perceive that you have a barrow to push (i.e. you are trying to guide them to an outcome favourable to you). If they do, it's bad for your credibility and long term relationship with the patient.
Therefore I always avoid sales techniques. For example, I would never say to the patient “Your investment will be…” when quoting the fee.
And if they asked me a question about whether they could get their work done by Christmas I would never reply “If we can get it done by Christmas would you like to proceed?”
Sophisticated patients (and even unsophisticated ones) will recognise those as sales techniques and you will lose authority. Patients should perceive you as their trusted dental advisor — never as a salesperson.
How do you position yourself to the patient?