A Professor is a Dozent, but a Dozent may not be a Professor. Moreover Dozent is not a title.
Privatdozent (PD) is a title.
Usually, Dozent includes Professor, apl Professor Privatdozent. More precisely, Dozent are persons, whose have right to give lectures.

From the homepage, 心下gave,there are two diferent lists:
one is for Professoren,
another is for Dozent.
Then it is clear that persons in the list of Dozent are not Professor

There are many homepages, which have only one list: Dozenten.
Then it includes both Prof. and PD.
But in this case, ususally one can see a title
(Prof. or PD, or Dr.) before names