Thanks for your answers.
@idolse
In the automatic process of calibre none hyphens were removed. The linebreak was removed and the hyphen is then in the word li-ke this. But at all I think these PDF are by some ways not standard. It worked automaticly with others. When I tried the expression -<br>.* and tested it (Great praise for the regular expressions assistent

) nothing was marked.
@all
I tried it with sigil but it is a lot of work. So I started at the roots and used OCR on the document and then sigil which was a bit easyer. I also tried some of the commercial pfd to epub converter. But I have to say that most of the time the result is not better than that of calibre often worse.
But then I found that the newest version of finereader converts scans and PDFs directly in epub. I got the trial and tested it. It worked marvellous! All hyphens removed. Pagenumbers invisible, even the big initials at the begining of a chapter were recognised and put in the flowing text.
If you are willing to pay money for epub conversion finereader 11 is defintily worth it and you get one of the best OCR programs.
I also like to say thank you to the developers of calibre. It is definiatly the best program for ebooks that is avalible. I got a reader only a short time ago and still working to get all my digital assest to work on that thing. Calibre helps a lot - so I can leave my laptop at home more often.
A donation for this great project will follow.
greatings from Germany
minorum