Table 1 Radiographic parameters for periapical status and root-filling quality

Periapical index (PAI)^a

1 = Normal periapical structures

Not pathological = 1 + 2

Pathological = 3 + 4 + 5

2 = Small changes in bone structure

3 = Changes in bone structure with some mineral loss

4 = Periodontitis with well-defined radiolucent area

5 = Severe periodontitis with exacerbating features

Apex-to-filling distance^b

1 = Root filling ending ≤ 3 mm from radiographic apex

Satisfactory = 1 + 4

Short = 2 + 3

Long = 5

2 = Root filling ending > 3 mm from radiographic apex

3 = Pulpotomy, material seen only in the pulp chamber

4 = Flush, root filling ending at the radiographic apex

5 = Over-filling, root filling material seen in the periapical area

Homogeneity of root filling^c

1 = Homogeneous root filling

Satisfactory = 1

Unsatisfactory = 2 + 3 + 4

2 = Minor irregularities in the root filling

3 = Voids in the root filling

4 = Larger voids in the root filling