. 2016 Feb 1;5:105. doi: 10.1186/s40064-016-1735-2

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

^aNoted one two or more aspects of the implants

^bMeasured on radiographs from time of definitive prosthesis loading to current radiograph. If not available, the earliest available radiograph following loading should be used