Recently got a letter from collection agency about unpaid dental bill from year 2000 never got a statement from the dentist?

Contact dentist immediately and see if you can still settle with dentist. If not, see if the collection company will give you a letter removing the late from your credit if you pay now in full. They will show you paid it in full but what you need is a removal letter from your credit if it was reported on your credit. Move quickly for the collection will stay on your credit 7-10 years.