When a probing depth reads 0.5 mm, what should you do?

When a probing depth reads 0.5 mm, what should you do?

• A. Record exactly 0.5 mm
• B. Round up to 1 mm
• C. Round down to 0 mm
• D. Record as 0

Answer: (B)

Rounding to the nearest millimeter is how probing depths are charted. A reading of 0.5 mm falls between 0 and 1, and the standard rule is to round half up, so it becomes 1 mm. Recording exactly 0.5 mm isn’t how depths are documented, and recording 0 would misrepresent any measurable pocket depth. The idea is to use whole millimeters so the chart remains consistent and clinically interpretable.

Rounding to the nearest millimeter is how probing depths are charted. A reading of 0.5 mm falls between 0 and 1, and the standard rule is to round half up, so it becomes 1 mm. Recording exactly 0.5 mm isn’t how depths are documented, and recording 0 would misrepresent any measurable pocket depth. The idea is to use whole millimeters so the chart remains consistent and clinically interpretable.