Just off the top of my head, I'd do something like below ... if no backup date appears, then there was no full backup after the last restore.

SELECT tdb.*, rh.restore_date AS Last_Restore, bs2.backup_finish_date AS Backup_After_Restore

FROM dbo.tUserDBs tdb

OUTER APPLY (

SELECT TOP (1) *

FROM msdb.dbo.restorehistory rh2

WHERE

rh2.destination_database_name = tdb.DBName AND

(rh2.restore_type IS NULL OR rh2.restore_type <> 'V')

ORDER BY restore_history_id DESC /*presumably accurate rather than datetime*/

) AS rh

OUTER APPLY (

SELECT TOP (1) *

FROM msdb.dbo.backupset bs2

WHERE

bs2.database_name = tdb.DBName AND

bs2.is_copy_only = 0 AND

bs2.is_snapshot = 0 AND

bs2.type = 'D' AND

bs2.backup_finish_date > rh.restore_date

ORDER BY backup_set_id DESC /*presumably accurate vs datetime*/

) AS bs2