My dentist causes me pain, so why don't I hate him?

The obvious answer is that you want him to do the work that is required on your teeth, and the pain is merely a necessary discomfort that is worth enduring.

My model of myself would predict that my emotional brain would generate feelings of dislike for my dentist that my rational part would suppress, yet there is nothing to suppress.

You have observed that your model is faulty. You should therefore update it. What is the problem?

Do other people respond this way as well?

I do not.