Thanks. Still no sign, and he’s getting tired of pooping into a seive. But yeah, we’re not going to do anything about it in terms of cutting him open to retrieve it unless symptoms develop. We were just hoping we wouldn’t have to pay to have a replacement made if we could (very thoroughly clean and) reuse the old one! 
no don’t need to retrieve it for reuse. Just take the denture to the dental office and ask them to add a tooth. In most metro areas sould be same day service. Drop off in morning pick up in afternoon. Not sure in rural areas though.