What 'function' will 'update' a post?

Question

I am using a script to import my vbulletin forum posts into wordpress as posts.

One quick issue I ran into is there are numerous forum posts with the same title 'please help me'.

When I go into the post edit screen the permalink will show 'please-help-me-2' for the second one, and 'please-help-me-3' for the third one. That is exactly what I expect.

However, when you go to view the second one on the front end of the website, instead of having the -2 appended to the end of the url, it simply says 'please-help-me'.

If I 'update' the post, then the permalink saves properly and the front end link changes like it should.

What I need:

Is there a function that I can use to go through the posts database and have it automatically 'update' all the posts so that the permalinks will change properly on the front end?

*we're talking 1.25million posts here, so automation is important.

thanks