The dentist used a new glue the last time this happened, and promised that it would last much longer. He was sort of right in that it lasted a couple of years longer, but it still fell out again. I guess that is one of the risks of having a conservative bridge1. The last time it fell out it had definitely been loose for awhile - enough so that I could wiggle it with my tongue. This time it didn't feel loose, but neither has the bridge felt right for the past few weeks - in fact it felt a little off when I was in for my last dental appointment, but he poked and prodded around and declared it fine at the time.
Ugh. I almost had myself steeled for a flu shot on Monday, and now it looks like I'll be getting some bonus Novocaine shots in the mouth first.
1 Rather than grinding the teeth down to little stumps like they do for a regular bridge, they just carve little valleys in the teeth and use fitted gold fillings to hold the bridge in place. It's not quite as secure, but it lets you keep more of your natural teeth. It works great until it falls out.