If it is waterproof, how can I remove it in case of emergency?

Normally, there is no need to remove the denture earlier, as long as  no food particles get trapped underneath. However, in specific cases – like accidents, x-ray…the denture can be removed by little force. Pull on the back up or down. It will be painless and will cause no negative effects, but residues of the adhesive might be left on the gum.