AcSmDatabase.UnlockDb
From AutoCAD Sheet Set Manager API

Unlocks the database.
Use the bCommit parameter to specify if changes should be saved to disk.
Syntax
UnlockDb(
pObject As Object,
bCommit As Boolean = True) As Object
| pObject | Input owner of the database lock |
| bCommit | Input Boolean specifying True if changes should be saved to disk |
| Comments? |