I would do a little research on which dentist place are "kid friendly". I just took my 3yr-old a month ago for the first time and she did great. Usually, they just start out wtih a look and see and if the child is tolerating that then they will try and clean the teeth. I think that it's recommended to wait until she is three to take them, because they can handle it better then, but if she is having problems or compalin of course take her. Also, for your peace of mind, take her ans they can just do a look and see too.
We live in Grimes and there is a great dentist here named Dr. Platt and they have a great kid set up!! My child did not want to leave!! They have a big screen T.V. in a little movie theater for the kids, in the waiting room, they are great wtih explaining to the children what they will be doing next, they get to wear funning sun glasses and during my childs flouride treatment she got to watch t.v. on a flat screen while in the dental chair. They also have a treasure chest at the end they they get to pick something out, and of course balloons!! The whole staff is very friendly!!
One more thing there is a toy by discovery toys that has a monkey where you mold his teeth with playdough and use pretnd dental tools to check the monkey's mouth etc. We have it and my daughter loves playing dentist!!
If you want more info, let me know. Good luck.