Thats a US thing; in Europe dentists do not try to "upsell" you any stuff, usually; for sure there are some shady practitioners, but their number is small. This behaviour is induced to how the local health schemes over here work: The doctor usually does not have an incentive to sell more stuff.

My experience from Denmark and Belgium is that dentists here will definitely disagree a lot.

I had one dentist tell me I needed 6 cavities filled. Let him do two and then went to another dentist who told me all my teeth were good. I've only ever had problems with the two teeth the first guy drilled.

Later a dentist wanted to drill another few teeth that were hurting. I instead got a better toothbrush and all the issues went away.

I Denmark we're talking about including dentistry in the national healthcare. I wonder if that will clean up the business or make it worse.