Don't use superglue!
If you mean "lose" as in cannot find, then you'll have to see a dentist to make a new one.
If you mean "lose", like came off the tooth while eating and i still have the crown
in my possession, then don't use superglue to replace it. Drugstores usually have temporary glue you can use, but eventually you'll have to see a dentist to get it replaced properly. This is much less costly than a new one.