Where should the probe tip be placed when beginning periodontal probing?

• A. On the enamel surface near the CEJ.
• B. At the gingival sulcus entrance, gently inserted into the sulcus.
• C. On the exposed root surface apically.
• D. At the gingival margin outside the sulcus.

Answer: (B)

Starting periodontal probing means placing the tip at the gingival sulcus entrance and gently inserting into the sulcus. This location lets you measure the depth from the gingival margin down to the base of the pocket, staying within the natural space between tooth and tissue. Placing the tip on enamel near the CEJ would not reflect a pocket depth and can risk tissue damage or an inaccurate reading. Probing an exposed root surface apically or placing the tip outside the sulcus at the gingival margin also fails to assess the true pocket depth and can cause discomfort or trauma. By entering at the sulcus entrance and advancing gently, you obtain an accurate measurement of the pocket depth.