Create a view like the following:
CREATE VIEW myView AS
SELECT CAST(CAST(StoredDoc AS NVARCHAR(MAX)) AS VARBINARY(MAX)) StoredDoc FROM myTable;Then write your application to read from the view instead of the table. Add any needed columns to the view definition when you create it.
FYI it's possible that the PDF data was corrupted when converting it to NTEXT, especially if it was compressed (most PDFs are).