I had to spend a lot of time in the chair and have anxiety so over time developed some rituals and thoughts to help me thru. It really has worked for me and I am so relaxed I almost fall asleep in the chair now.
1) Know that the discomfort of dental work is a trade off. It is a short termed discomfort to prevent really bad long term problems.
2) The dentists and assistants are like doctors and are there to help you avoid serious pain and problems. As such they are friends rather then foes. They still are just humans and you get good and bad personalities but by and large they are mostly ok people.
3) I chat them up as much as possible during the work (Can be difficult with all the apparatus
). One, I want them to like me so they are extra careful, and two it helps distract me from what they are doing. I try not to pay attention to what they are doing. Just tell me when we are done.
4) During things I know might hurt, like shots, I pinch myself or push a finger into my palm to create a sensory distraction. The brain has to split its focus and so the two things are lesser intensity individually. I also will focus on something like ceiling tiles etc, and try and force myself not to think about what is going on. You get better at it with practice.
5) As soon as I get to waiting room to show up for appointment I begin relaxation techniques. Even breathing, relaxing your body, emptying your mind of worries, and thinking about simple pleasing things. Its better to be loose and relaxed then tight muscle wise. If you get tense, well it happens. Just breath regularly and focus on relaxing again. I have got so good at this I almost am drifting out of consciousness when I get to the chair.
Most visits go pretty good and aren't worth worrying about and so the chances of a good visit outnumber the chances of a bad one. The science always improves.