S.B.
I started taking my kids to the dentist when I had my own appointment as soon as they got their first tooth. They would lay in my lap for the first part of my exam, get their own little 2 minute exam, and then I would have a helper with me to keep them in the waiting room for the rest of my exam. At two years old, I started making their own appointments for "true exams." By that time, they had already been to the dentist a few times with me and were not in the least bit worried about it.
Good luck!