My son who is 8 has never had a cavity, but my daughter (almost 5) had a small filling a few months ago. She was great and didn’t need any sedation or novacaine, but it was very minor work.
I think a pediatric dentist is a must for a 3 year old who needs work done. We go to Dr. Rawlings in Encinitas. Everyone on the staff is great and my kids actually look forward to going to the dentist.
I also think a lot depends on your child’s personality. My son would probably need elephant darts since he is a very anxious kid. My daughter is much more easy going and she breezed through it without a second thought. A good pediatric dentist will have a lot of experience putting kids at ease.