Presumably this happened and you did nothing when it did happen. In addition to any passage of time issue, what do you want to have happen? Even proving it was in the food at this point could be difficult. The best way to prove it came from the restaurant would be to find out if someone lost a tooth who works there. It could be an expensive porcelain crown that fell out while someone was preparing food and didn't notice until later -- disconcerting but not impossible. If it did not harm you again what would you want to have happen? Typically you can't recover damages if you were not harmed, even if the idea is gross. You'd most likely have to prove some kind of physical or emotion reaction that required you to seek professional help at your cost...... Maybe take it to your dentist and ask if it's really a tooth or a complete crown and take if from there?
