My mother in law was an office manager at a dentist. Dentists have sales quotas and have bonuses to everyone in the office for upselling.

You go in to a medical professional for health care and advice and they try and sell to you.

I recommend reading this article “I Went to 50 Different Dentists and Almost All of Them Gave Me a Different Diagnosis”:

https://www.rd.com/article/how-honest-are-dentists/

In Canada it’s two reasons:

• They don’t go to Medical School.
• They aren’t covered by Provincial Health Plans, and therefore cost money.

These are the same reasons I don’t trust Veterinarians, or Chiropractors. Ill give Dentists and Vets credit that they’re at least studying real science.