Abstract
Clinical evaluation was performed on 6 teeth in 18 generally healthy subjects. They were divided into the following 3 groups: healthy subjects, healthy sites and active sites of gingivitis. A total of 108 dental crevices or periodontal pocket samples were analyzed microbiologically.
The total number of cultivable bacteria, the number of black-pigmented anaerobic rods (BPRs), and the percentage of BPRs to the total number of bacteria in the active gingivitis sites (31 sites) were significantly higher (p<0.05) than in those of the healthy subjects (36 sites) and in those of the healthy sites of gingivitis (41 sites). The percentage of Prevotella intermedia to the total number of BPRs in the healthy and active sites of gingivitis were 38.1 and 34.2%, respectively, and were higher than in the healthy subjects (7.1%). However, the percentage of Prevotella nigrescens to the total number of BPRs in the healthy and active sites of gingivitis were 18.6 and 24.3%, respectively, and were lower than in the healthy subjects (40.9%). The percentage Porphyromonas gingivalis to the total BPRs in the healthy and active sites of gingivitis were 0.2 and 5.2%, respectively, and this bacterium was not found in the healthy subjects. The numbers of P. intermedia, P. nigrescens and P. gingivalis were the highest in the active site of gingivitis, and were higher in the healthy sites of gingivitis than in the healthy subjects.
Consequently, BPRs, especially, P. intermedia and P. gingivalis seemed to be the putative pathogens of gingivitis. These putative pathogens might be transmitted from the active to the healthy sites in gingivitis, because the numbers of P. intermedia and P. gingivalis in the healthy sites of the gingivitis were also higher than in the healthy subjects. J. Jpn. Soc. Periodontol., 41: 277-286, 1999.
