Database looping is usually caused by corruption in the database files. Since it is a database corruption, it can be unrecoverable. There are several options:
Revert to the hot backup.
If the corruption occurred recently, you can use one of your hot backups.
Use your catastrophe archival recovery process.
For a suggested process, see 22.5.8 Restoring an Automatic Backup Copy.
Use the dump and reload procedure, 22.5.7 Using the Dump and Load Procedure to Recover a Calendar Database.