The effectiveness of subgingival scaling and root planing. II. Clinical responses related to residual calculus.

This study related 3-month clinical changes following scaling and root planning to the presence or absence of calculus on the root surfaces detected after extraction. Seven patients provided 646 sites evaluated for plaque, bleeding upon probing (BOP), probing pocket depth (PPD), and probing attachment level (PAL) at baseline and monthly following instrumentation. The teeth were extracted and evaluated for the presence and the percent surface area of calculus. Diagnostic sensitivity and predictability values for initial and residual PPDs, loss of PAL, and BOP in detecting residual calculus were determined. Calculus was found on 376 surfaces with a mean percent surface area of 3.13%. Predictability values were similar for all PPD ranges, while sensitivity decreased with increasing PPD. Probing attachment level changes were found to be unrelated to the presence or the amount of residual calculus. Bleeding upon probing had high levels of predictability, but sensitivity values were low. None of the clinical parameters evaluated in this study provided both a high level of predictability and sensitivity in detecting residual calculus.