The First Faculty of Medicine, Charles University in Prague, Czech Republic has a very reputed dentistry program in Central Europe. It's hard, rigorous but most people who've graduated from there have done/are doing quite well for themselves.
In Poland, I think the good ones are Poznan University, Warsaw University, Gdansk University.
In Hungary, Debrecen Uni., Semmelweis Uni., and Pecs Uni.
In the Czech Republic, apart from the First Faculty in Prague, there are also other good ones: Dentistry at the Faculty of Medicine in Hradec Kralove, and at Masaryk University.