My dentist isn’t certain if I should have a bone graft or not, what should I do?

Q. Hi, I have had x-rays, ct scan and the thickness of my bone measured. I have been told that I should not need a bone graft but he could not say for certain until he opens up the gum, is this true? I thought these tests would prove whether bone grafting is required or not. As when he opens up gum and procedes if he said it is required the the price rises alot.,