I didn't take my oldest until she has 5 and my youngest just went at 2.5 years old. My oldest made strange really bad as a baby/toddler and I knew she wouldn't let the dentist near her until she was older and grew out of that fear.

The dentist doesn't really do much anyway at such young ages and I had no concerns about their teeth. And the dentist found zero issues with either child's teeth. With my 2 year old daughter the dentist said I didn't need to bring her back until she was 4 years old for another checkup - so not for another 2 years. Waiting until they were older didn't affect their fear of the situation, we made it a positive and exciting experience to get to go to the dentist. They had no reason to be afraid, they hadn't associated dentists with pain (yet anyway!).