Table 1 Classification of peri-implantitis (Froum and Rosen 2012)

Early

PD ≥4 mm (bleeding and/or suppuration on probing)^a

Bone loss <25 % of the implant length^b

Moderate

PD ≥6 mm (bleeding and/or suppuration on probing)^a

Bone loss <25–50 % of the implant length^b

Severe

PD ≥8 mm (bleeding and/or suppuration on probing)^a

Bone loss >50 % of the implant length^b