Some dental students from Ohio State came to our class a couple weeks ago and did some activities with the kids. They split the class up into 2 groups. The first group was sorting felt foods into 2 categories: Foods that make your teeth happy and foods that make them sad.
The second group got to dress up like dental hygienists and pretend to clean teeth and put in fillings. Then when each group was done, they switched.
The kids really had a blast! The dental students were so good with the kids and I would recommend doing this in your classroom! The only regret I have is that we didn't know about it until an hour before they showed up, so we didn't have a chance to do any activities or discussions leading up to their visit.