I got three fillings done on Wednesday. This appointment went way better than the first one. It bordered on fun, even. The needle used for the local anesthetic is 27G, and the dentist used a topical before injecting, so I didn't feel much- mostly the suction of it coming out bugged me. I got two shots of the painkiller since I could still feel a lot after the first- as far as I could tell the second one didn't really make a difference. I felt a fair amount of pain when the cavities were being scraped out (at the most acute it was like having a shot with a 22G needle), and the cotton in my mouth didn't feel so great either, but overall I was really really sleepy and that prevented me from feeling much. Local anesthetics are not supposed to cause sleepiness and I'm not sure if they did in my case or if that was a coincidence.
My bloodsugar had been dropping before the fillings and anesthetic, and continued to drop afterwards; as far as I can tell the painkiller had no effect on my insulin sensitivity.
One thing I hadn't realized was that the dentist wouldn't want me to be eating afterwards, and my stuff to treat hypos all needed some chewing. As I was hypo at the end of the fillings, the dentist gave me a lemonade juice box (25 grams of carbohydrate of which none were fiber) and that kept my blood sugar up until the anesthetic had largely worn off. During the filling, my lip and tongue both got cut a little bit, and my gums are still a teensy bit sore, but mostly it's all better. Yay!