I'm not entirely clear on what you mean, but I'll offer this. This applies only if you have users completing PDF forms and submitting them. Instead of having users submit the PDF form, just have them submit the data in an HTML form. Store that in a database. When they want to view/print the data, populate the PDF form using FDF. That way if somebody pulls up the PDF through the URL, it will be blank (or populated with the data from the last one they viewed).
Hank