Hi Rafael,
Personally I felt the Dental Decks helped some, but I couldn't rely totally on them. After my class took the NBDE Pt1 in July, my impression is that a lot of materials in the exam, particularly in the anatomical sciences, weren't covered by the decks (at least not to the level of detail on the exam).
I would look at old NBDE exams as well as generally reviewing some of the critical areas you know they will sure as heck ask questions on (such as muscles and AVNs in the head and neck, etc.).
The only part of NBDE I thought were cakewalks was Dental Anatomy (which for the most part is common sense).
Good luck!