Table 1 Definition of the classes used to annotate the dataset

Grade 1

Radiolucent in outer half of the enamel [21, 22]

Grade 2

Radiolucent in the inner half of the enamel, but not in the dentine [21, 22]

Grade 3

Radiolucent in the outer third of the dentine [21, 22]

Grade 4

Radiolucent in 2/3 of the dentine [21, 22]

Grade 5

Radiolucent in the inner third of the dentine [21, 22]

Secondary lesion

Caries related to sealants or restorations

Unknown grade

Caries whose grade cannot be clearly identified