Only one rule is needed, along with some corrections to the subpatterns and corrections as noted above:
RewriteRule ^topic/([0-9]+)[.;][0-9]+-$ http://www.example.com/ipb/topic/$1- [R=301,L]
Again, this is a redirect. It does not change the URL or change the filepath associated with the URL. It simply tells the browser to re-request what it wanted the first time, but using the new, shorter URL. If you actually want to change the URL, then you will have to edit your HTML pages or edit the script(s) that produce those HTML pages. It is HTML pages, not servers, that define URLs.
Be sure that before using this code, you correct all of the links on your site to use the new shorter format. The major search engines "don't like it" when they follow a link from your own site to your own site, and encounter a redirect... That indicates poor site management, and cannot be a help to your pages' rankings...
Jim