[The prognostic significance of the presence of Actinobacillus actinomycetemcomitans in the subgingival plaque of young orthodontic patients].

The aim of present study was to evaluate the prognostic significance of the presence of Actinobacillus actinomycetemcomitans in subgingival plaque from young patients wearing fixed orthodontic appliances. Fifteen orthodontic patients, 3 males and 12 females, aged 10 to 27, systemically healthy, participated in the study. First examination took place in the spring of 1992 (T1) and consisted in the collection of clinical (pocket depth, PD; Gingival Index, GI; Plaque Index, P1I; Gingival Bleeding Index, GBI) and microbiological (Actinobacillus actinomycetemcomitans presence) parameters in 4-8 periodontal sites in each patient. The same clinical and microbiological parameters were collected again in the spring of 1994 (T2). Results showed that the presence of Actinobacillus actinomycetemcomitans in the examined periodontal sites underwent fluctuation, 25% of sites being positive for the sought after bacterium in T2 whereas the percentage of Actinobacillus actinomycetemcomitans positivity in T1 was 47.5% with a statistically significant difference (p < 0.005). On the contrary clinical parameters did not show significant modifications through the study period T1-T2. Differential analysis of clinical parameter modifications in relation to Actinobacillus actinomycetemcomitans positivity in T1 or Actinobacillus actinomycetemcomitans-positivity fluctuations in T1-T2 period did not evidence any significant difference among various microbiological conditions. The authors conclude that the mere presence of Actinobacillus actinomycetemcomitans in subgingival plaque from specific periodontal sites in young orthodontic patients does not seem sufficient to consider those sites at risk for periodontal destruction in the medium-short term.