If she doesn't cut back on the sweets then yep, he should be a lot of fun as he deals with the spunky girl. It's good that he has so much patience for his… uhm, patients. Also, it's even better that he'll fill a cavity right away after the examination rather then make them schedule another trip. (At least in the U.S. that's common, supposedly for tighter scheduling… but it just happens to let them charge for the overhead of another visit too.)
Also, none of my dentists ever gave me a toothbrush nor a tiny tube of toothpaste. I didn't even consider they'd do that. I think I missed a chance with Alexis, there.