Quoted from Aurich:Pic would help. I just sculpted teeth for my Elvira skull cave out of a two part Kneadatite epoxy, and along with the epoxy used some super glue. Not that relevant to you. But one other thing is did was build little braces out of paperclip wire, which i embedded in the back of the teeth and then up into the skull. So if the teeth are hit some of that impact energy will be absorbed up into the main skull cavity. You might be able to explore some methods that will help the glue take an impact.
So there are options besides just glue, depending on the situation. Post that photo!
Steve Young at Pinball Resource sells an assortment of piano wire, and I've used it to reinforce plastic when I glue it. The piano wire is much harder and springier than a paperclip. I've also used fiberglass cloth, and fiberglass drywall tape.