My children never had more than some tiredness, numbness, and mild discomfort the day of their fillings or crowns. My husband on the other hand has tooth pain for a couple days after he has dental work done. My first son had weak front baby teeth and we went through similar to yours, getting fillings as a toddler, going on to crowns about 3 or so. His adult teeth now seem healthy and strong though, and he's relatively relaxed about cleanings now despite it all. My second had some fairly shallow molar fillings at age 5, no numbing and no pain. They never underwent sedation though, only numbing and watching tv during procedures. I expect that would leave them extra groggy for a while.