How much pressure should be used when probing?

• A. 100-200 grams
• B. 10-20 grams (enough to blanch a fingernail)
• C. 1-2 pounds
• D. 50-60 grams

Answer: (B)

Use a light, steady touch when probing. The goal is to read the tissue depth without distorting the sulcus or causing harm, so only a gentle amount of force is applied. About 10-20 grams of pressure is the recommended range, which you can gauge by the slight blanching of the nail bed as you apply the force. This blanching signal helps you stay in the correct range and avoid excessive pressure.

Pushing harder—such as 50-60 grams, 100-200 grams, or more—can injure tissue, cause bleeding, and distort readings by compressing the tissues, leading to inaccurate measurements and patient discomfort. So the 10-20 gram range is the best match for accurate, safe probing.