Effect of treatment on some periodontopathogens and their antibody levels in periodontal abscesses.

Twenty patients suffering from abscess of periodontal origin were treated and followed clinically and microbiologically for 6 months. Microbiological examination was performed by culture technique. One deep and one shallow periodontal pocket in the same patient were examined concomitantly. Serum was collected and analyzed for specific antibody level using ELISA methodology. Treatment included supragingival scaling, drainage, and irrigation of the periodontal pocket with 0.85% sodium chloride and systemic tetracycline administration, 1 g per day for 2 weeks. At baseline, 90% of the abscesses harbored Porphyromonas gingivalis and/or Prevotella intermedia. After 6 months, abscess sites demonstrated a reduced probing depth, less bleeding on probing, and gain of attachment. Abscess sites showed no P. gingivalis and the proportion of P. intermedia was significantly reduced 6 months after treatment. In deep periodontal pockets a similar pattern was seen. Shallow pockets demonstrated few clinical signs of inflammation and the number of bacteria was generally low. Campylobacter rectus, Capnocytophaga spp, and Fusobacterium nucleatum were frequently seen in low numbers in most sites during the study period, while Actinobacillus actinomycetemcomitans was detected only in a few sites. The IgG levels in patient sera against antigens of homologous bacterial strains remained fairly constant for 6 months. The result of the present study indicates that P. gingivalis and P. intermedia are involved in periodontal abscess formation. Also, treatment where drainage is combined with tetracycline administration promotes healing and reattachment.