I used to be scared when I was going to the pediatric dentist, but could tolerate treatment. The thing is that the dentist and my mother never told me that to help me they would always do a small amount of work at each appointments (for example, do only 2 fillings at a time) and book more time then needed (for example, booking 1 hour for treatment that would be done in 15 minutes). I would sometime get a panic attack, but usually would calm down enough for them to finish treatment. My other issue would also be gag reflex, but we would usually be able to work around it.
When I moved out to a different city, I had to see a different dentist. When I needed treatment, he decided to book me for 4 fillings in a 1 hour (I didn't ask for something shorter since the Christmas holidays were a week away and wanted everything before going on vacation, plus I didn't know I would usually get shorter appointments from my old dentist to help me cope) and they offered laughing gaz, which I tough would help me. I had a panic attack and couldn't calm down. Thankfully, being close to work, someone from work was eventually able to come in to talk to me and I was able to calm down to get the work finished. The dentist himself wasn't so nice about it making me feel bad about the whole experience, but thankfully his staff was nicer. I felt ashamed of myself from getting a panic attack while in the chair. For the laughing gaz, I don't think I felt much of an effect on me. I'm not sure what triggers my panic attacks.
I decided to go see a dentist who could do IV sedation. So now, most of my treatments are done with sedation. I would like to eventually go see a dentist who could help me go back to get treatment with simply some local anesthesia, but would like to reach a state were I feel comfortable with my teeth first. My issue right now is feeling pain in some places in my mouth, but when I go to the dentist, he says it all seems good, without offering much more. Thankfully the pain and stress eventually comes down once I know it doesn't seem to be dental, but I always wonder what it is and if I will end up in more pain.