I have about 25 custom .dot files that all use the same set of paragraph and
character styles that I defined. Is there any way to prevent users who create
..doc files based on one of these templates from changing or adding styles to
these templates?

One of the useful/frustrating things about Word is the ability to drive a
paragraph or character-style change from a .doc back into the .dot. I need to
prevent this before I roll these templates out to novice MS Word users.

Thanks for any suggestions you can provide.