Table 1 Classification of the breaking modes and their characteristics

I

Adhesive cement fracture on the abutment

The abutment is largely cementless. The cement is completely in the crown lumen.

II

Adhesive/cohesive cement fracture on the abutment

There are cement residues on the abutment but not to an extent of the full thickness of the cement film. The majority of the cement is located inside the crown.

III

Cohesive cement fracture

The abutment and the crown lumen are mainly covered with cement. The separation takes place within the cement film.

IV

Adhesive cement fracture at the crown

The crown lumen is largely free of cement. The cement is completely on the abutment.

V

Adhesive/cohesive cement fracture at the crown

In the crown lumen are cement residues but not the full thickness of the cement layer. The majority of the cement is on the abutment.