If calculus touches the bisecting line between contacts of adjacent teeth, how would you rate it?

• A. Light calculus
• B. No calculus
• C. Heavy calculus
• D. Moderate calculus

Answer: (C)

Proximal calculus grading uses a landmark between adjacent teeth to judge how much deposit is present. When calculus touches the bisecting line between contacts, it shows a substantial buildup on the proximal surfaces—enough to reach that key threshold. That level of accumulation is classified as heavy calculus because it indicates more extensive deposits that are harder to remove and may extend toward or onto the root surfaces.

In contrast, deposits that stay coronal to that line would be considered lighter, and those that merely approach but don’t reach it would fall into less severe categories. Here, touching the line signals the highest level among typical proximal classifications.