4-year observations of basic periodontal therapy.

A total of 2214 sites from incisors, cuspids, and premolars were studied in 46 adult periodontitis patients following treatment consisting of plaque control and root debridement. The periodontal status at 24 months was used as baseline for observations during the subsequent 24-48 month interval which included 4 recall visits for debridement at the 24-, 30-, 36-, and 42-month time points. The data were analyzed for pooled groups of sites of different probing depth at 24 months: less than or equal to 3.5 mm, 4.0-6.5 mm, and greater than or equal to 7.0 mm. The results showed little change during the 24-48 month interval in mean scores for bleeding on probing, probing depth, and probing attachment level for all 3 groups of sites. Individual sites with probing attachment loss during the 24-48 month period were identified. The frequency of such sites was similar, irrespective of 24-month probing depth. The sites identified with probing attachment loss during the 24-48 month interval generally differed in location from those identified as having probing attachment loss during the preceeding 0-24 month period. Often, the loss of probing attachment during the 24-48 month interval seemed to be a reversal of a prior gain in probing attachment during the 0-24 month interval. This study in non-molar teeth of subjects with generally good level of compliance failed to demonstrate that sites with deeper probing depth were more difficult to maintain than shallower sites.