The effectiveness of subgingival scaling and root planning. I. Clinical detection of residual calculus.

This study evaluated the ability of clinicians to detect residual calculus following subgingival scaling and root planing and compared the clinical detection to the microscopic presence and surface area occupied by calculus found on teeth extracted after instrumentation. Interexaminer and intraexaminer reproducibility in clinically detecting subgingival calculus was also determined. One hundred one extracted teeth with 476 instrumented tooth surfaces were evaluated stereomicroscopically for the presence of calculus and the percent surface area with calculus was determined by computerized imaging analysis; 57% of all surfaces had residual microscopic calculus and the mean percent calculus per surface area was 3.1% (0 to 31.9%). Shallow sites had greater surface area of calculus than moderate and deep sites. The difference was not significant. The interexaminer and intraexaminer clinical agreement in detecting calculus was low. There was a high false negative response (77.4% of the surfaces with microscopic calculus were clinically scored as being free of calculus) and a low false positive response (11.8% of the surfaces microscopically free of calculus were clinically determined to have calculus). This study indicates the difficulties in clinically determining the thoroughness of subgingival instrumentation.

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.