Which option describes the Plaque Index across all teeth?

• A. Measures thickness of calculus on tooth surfaces.
• B. Measures thickness of plaque at gingival margin (all teeth).
• C. Measures probing depth.
• D. Measures extent of gingival recession.

Answer: (B)

The main idea here is that the Plaque Index assesses how thick dental plaque is at the gingival margin on all teeth. It involves examining each tooth (around the gum line) and scoring the amount of plaque, then averaging those scores to get an overall measure of plaque control for the dentition. This is distinct from indices that measure calculus (hardened mineralized plaque), probing depth (how deep the gum pockets are), or gingival recession (how far the gum line has receded from the tooth). So describing it as measuring the thickness of plaque at the gingival margin across all teeth is exactly what this index is meant to capture.