Table 1.

Classification of the failure modes.

Type	Failure mode	Description
I	Cohesive failure	Fracture of the endocrown without displacement (loss of adhesion)
II	Adhesive failure	Debonding of the endocrown without fracture
III	Cohesive-adhesive failure	Fracture of the endocrown with displacement (loss of adhesion)
IV	Fracture of the restoration/tooth complex above CEJ	Fracture of the endocrown and the tooth above CEJ
V	Fracture of the restoration/tooth complex below CEJ	Fracture of the endocrown or/and the tooth below CEJ, which require tooth extraction

CEJ: Cemento-enamel Junction.