Loe & Silness Gingival Index (GI)
Score 0 = Normal gingiva.
Score 1 = Mild inflammation - slight change in color, slight edema. No bleeding on probing.
Score 2 = Moderate inflammation - redness, edema, glazing. Bleeding on probing.
Score 3 = Severe inflammation - marked redness and edema, ulceration. Tendency toward spontaneous bleeding.
"The bleeding is assessed by probing gently along the wall of soft tissue of the gingival sulcus. The scores of the four areas of the tooth can be summed and divided by four to give the GI for the tooth. The GI of the individual can be obtained by adding the values of each tooth and dividing by the number of teeth examined. The Gingival Index may be scored for all surfaces of all or selected teeth or for selected areas of all or selected teeth. The GI may be used for the assessment of prevalence and severity of gingivitis in populations, groups and individuals. A score from 0.1-1.0 = mild inflammation; 1.1-2.0 = moderate inflammation from, and 2.1-3.0 signifies severe inflammation. The GI has been used frequently in clinical trials of therapeutic agents The sensitivity and reproducibility is good provided the examiner's knowledge of periodontal biology and pathology is optimal."
Journal of Periodontology, Nov-Dec 1967, Vol. 38, No. 6, Pages 610-616. Harald Loe.