I had something similar happen to one of my teeth. I was also eating some pizza that had a crispy crust. I bit into it and felt instant pain in one of my back teeth. I could feel something move when I touched my tongue to it. I had an appointment in a couple day with my hygienist (sp?) so I just waited til then.
She was very gentle while cleaning my teeth and didn't find anything wrong. She even took several x-rays and nothing showed up. She was quite confused at to what was wrong with the tooth. She called in my dentist to check my teeth and he gently probed and found the problem. The entire side of my tooth had completely broken and was only held in by a piece of gum tissue. My hygienist was shocked that she didn't find it and that it didn't show up on x-ray. I am now waiting to have a crown put on that tooth. I have already had the root canal done.
I think the world of the dental office I go to. They are wonderful with extreme dental cowards like me.