[Movements of the supporting teeth in Kennedy-Applegate class III and IV restorations]

Two types of restoration of the class III and two types of the class VI have been tested on a test bench. These restorations react differently to vertical forces than to oblique ones. The fixed bridge reacts best to vertical forces. On the other hand it is the bilateral prosthesis with four Akers clasps which is more favorable to oblique forces. The enclosed saddles function, in this case, as a brake. When the global results (vertical and oblique forces) of induced movements are compared for the two types of class-III restoration (four Akers clasps or two Dolder bars) the differences are insignificant.