The Add to Teamcenter process is optimized to improve the start of the application and to delay the Teamcenter login to only appear when you:
Click Browse for Folder.
Select the Revision Rule list.
Click Cache Assistant.
click OK to start the import of unmanaged documents.
The result is an improved interaction with Add to Teamcenter.
See the Add unmanaged documents to Teamcenter help topic for additional information.