When we have patients that “know what treatment to do”, and just want you to do what they say, or tell you they want a discount, for whatever reason that seems reasonable to them, many dentists go into a full explanation. If it’s related to the treatment the patient believes should be done, the dentist starts explaining, in minute detail, the intricacies of the procedure he/she wants to do. If it’s a discount related question, I often hear dentists go all squirly and start outlining the issues with rising overhead, and PPE costs, scheduling challenges, etc.
But as soon as you start to justify whatever it is you want to disagree with them on, they don’t hear you. They tune you out. And frankly, that’s pisses me off and it’s a complete waste of your valuable time.
So here is what works really well for me:

When a patient tells me to do something I can’t possibly do, or asks me for a discount, I simply say:

How do you want me to do that?
You tell me, Mr. Patient.
How do you want me to do this?
Well, you are the dentist!
I don’t know how you are going to do this… Neither do I. So you tell me.

Throw it back at them. Less is more.

Dentists always want to justify everything; we give data, supporting facts, go into detail about overhead… Stop. Keep it simple.

Tell me how to give you what you want? Tell me how to do that.

They don’t know how, they just want what they want. And when you ask them to figure out how, they get confused. And when that happens, that’s your opportunity to shine.