Correlation of histometric, microbial, and clinical indicators of periodontal disease status before and after root planing.

Effective diagnosis and treatment of periodontal disease requires accurate evaluation of disease status before and after treatment. This study evaluated relationships among multiple parameters that have been used for periodontal disease evaluation. A total of 61 initially deep (greater than or equal to 6 mm) interproximal pockets from 16 patients examined before and after a 3-week course of root planing therapy were evaluated for probing depth, bleeding on probing, darkfield and cultural characterization of subgingival plaque, and histometric indices of infiltrated connective tissue (ICT) and mature plasma cell infiltrate. 36 sites were evaluated before treatment, and 25 after treatment. A comparison of mean scores for pre-treatment sites versus post-treatment sites indicated that there was an average improvement in most disease-related parameters. However, patterns of significant correlations among the parameters differed markedly. Motile bacteria enumerated by darkfield microscopy were significantly correlated with ICT and plasma-cell populations before, but not after treatment. In contrast, probing depth and populations of black pigmented Bacteroides (BPB's), principally B. gingivalis, were significantly correlated with ICT after, but not before, treatment. Bleeding on probing was not significantly correlated with ICT levels before or after treatment. This suggests that different sets of parameters should be used for evaluating periodontal disease status before or after treatment. Our data further suggest that B. gingivalis populations may be related to delayed healing of deep periodontal lesions after instrumentation.