Plaque thickness

Silness–Löe Plaque Index: the 0-to-3 scale

The Silness–Löe Plaque Index describes plaque around the gingival margin. The classical method assesses four surfaces of each examined tooth.

Classical method

Surfaces are scored from 0 to 3: 0 means no plaque; 1 is a thin film detected by a probe; 2 is moderate visible plaque; and 3 is abundant soft deposits. The result is an average.

Practical interpretation

0: excellent
0.1–0.9: good
1.0–1.9: satisfactory
2.0–3.0: unsatisfactory

Silness–Löe calculator

Add the scores for all examined surfaces and enter their number.

Index = total surface score ÷ examined surfaces

Educational calculator. The result is not a diagnosis and must be interpreted with the clinical examination.

How Odonta Index AI uses it

A photo shows disclosed-plaque distribution but does not replace probing and examination of all four surfaces. The report therefore presents a screening estimate for clinician confirmation.

Original publication

Silness & Löe, 1964 — Plaque Index

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