We went through this when our son was almost 3. He had 3 pulpectomy's (baby root canal) and 4 crowns. It took about 2 hours under anesthesia. It was the scariest thing I had ever done at the time, but he came through just fine. He's 7 now, and while his baby teeth were a crumbly mess, I'm happy to report that his permenant teeth are absolutely normal thus far.