Effects of subgingival irrigation on A. actinomycetemcomitans.

The effects of repeated subgingival irrigation on Actinobacillus actinomycetemcomitans was examined. 24 periodontal pockets harboring A. actinomycetemcomitans in 3 juvenile and 4 adult periodontitis patients were studied. The protocol included bi-weekly subgingival irrigation with hydrogen peroxide of the periodontal sites until the micro-organism was no longer detected by selective culture, or for 6 months. A. actinomycetemcomitans was gradually suppressed to below detection following the irrigation regime and could no longer be detected in 46% of the sites at completion of the irrigation protocol. The sites were microbiologically re-examined 5 months after cessation of the irrigation regime. A. actinomycetemcomitans re-occurred in only 2 of the sites from which it had originally been suppressed below detection. The results indicate: (1) that the irrigation regime tested has some potential to suppress A. actinomycetemcomitans in periodontal pockets; (2) that the effect of the irrigation protocol generally lasted for 5 months; (3) that the reduction rate of A. actinomycetemcomitans to below detectable levels seems related to the initial number of cultivable bacteria from the periodontal pocket.