Which type of shank is best for detecting subgingival calculus?

A flexible shank is particularly well-suited for detecting subgingival calculus because it allows for enhanced tactile sensitivity and adaptability to the contours of the root surface. This flexibility enables the instrument to navigate deeper into the periodontal pockets without risking trauma to the surrounding tissue.

When using a flexible shank to assess areas under the gum line, the instrument can effectively feel the texture of the root surface and discern discrepancies that indicate the presence of calculus. The adaptability of the flexible shank provides the clinician with a better feedback mechanism, essential for thorough exploration and accurate detection of deposits hidden below the gum line.

In contrast, a rigid shank would lack the necessary sensitivity and could make it difficult to detect the nuanced variances in texture associated with subgingival deposits. Moderately flexible shank options might offer some benefits, but they may not provide the same level of sensitivity as a fully flexible shank. An extra rigid shank would be the least suitable for this purpose due to its inability to conform to the anatomical structures and limited ability to detect soft deposits like calculus effectively.