Abstract
Asaccharolytic pigmented Porphyromonas strains were isolated from the plaque of dogs with gingivitis and periodontitis. Various species of Porphyromonas, including P. endodontalis, P. gingivalis, P. circumdentaria and unclassified species, were detectable. Canine Porphyromonas were sensitive to Japanese green tea extract (JGTE). We examined the effects of dietary JGTE on periodontal diseases. A special diet was prepared on the basis of the minimum inhibitory concentration (MIC: 0.8 mg/ml) of JGTE to several canine Porphyromonas species. Growth of all Porphyromonas isolates was inhibited at this concentration. After 2 mths, the percentage of canine Porphyromonas significantly decreased in the plaque microbiota. Concurrently with the observed decrease in percentage of these bacteria, gingival inflammation was inhibited. However, no change in the calculus index was recorded during the observation period. Levels of oral malodour varied among the dogs and diet with JGTE was effective in the inhibition of oral malodour. We concluded that JGTE was effective in the inhibition of canine periodontal diseases.