Quantitative bacteriology of acute dento-alveolar abscesses.

A qualitative and quantitative bacteriological study was performed on pus specimens obtained by needle aspiration of 50 acute dento-alveolar abscesses. Most samples contained a mixture of species (average 3.3); 20 (40%) of the abscesses contained anaerobes alone, 3 (6%) contained facultative anaerobes only and the remaining 27 (54%) contained mixtures of both types of bacteria, with anaerobes predominating. In total, 166 bacterial strains were isolated, 75% of which were strictly anaerobic; the most common species were Peptococcus spp, Bacteroides oralis and B. melaninogenicus. Among facultative anaerobes, Streptococcus milleri was particularly common. The mean concentration of bacteria in each abscess was 10(6.9 +/- 0.2). The mean concentration of anaerobic bacteria was 10(6.2 +/- 0.1) and of facultatively anaerobic bacteria 10(5.7 +/- 0.2).