The relationship between gingivitis and plaque levels.

Some confusion exists in the literature whether correlations exist between gingivitis severity and plaque levels as measured by the corresponding indices. The results of a clinical trial and a re-analysis of literature data indicate that a strong statistical correlation exists between the Löe-Silness Gingival Index values and both the Löe and the Quigley-Hein Plaque Index measurements. Furthermore, regression analyses also indicate that Löe-Silness Gingival Index can be expressed as linear functions of either the Löe Plaque Index or the Quigley-Hein Plaque Index and that for each unit increment in the mean plaque index values a half unit increase in the gingival index value can be expected.