PREDOMINANT CULTIVABLE MICROFLORA OF SUPRAGINGIVAL DENTAL PLAQUE IN CHINESE INDIVIDUALS

The aim of this study was to determine the predominant supragingival c ultivable bacterial flora in Chinese individuals, using the experiment al gingivitis model. A total of 11 healthy dental students, mean age 2 2.5 years (range 20-25) were recruited. All were provided with once-a- week dental prophylaxis and oral hygiene reinforcement for 3 weeks to ensure gingival health. In the fourth week, after prophylaxis, the par ticipants entered a 14-day period without any plaque control. A plaque sample was collected at days 1, 3, 7 and 14 from the buccal surface o f the upper right canine, second premolar, first premolar and first mo lar, respectively. Each sample was then dispensed in tryptic soy-broth transport medium and grown anaerobically to obtain pure cultures, whi ch were subsequently identified Results showed that Gram-positive cocc i and rods were the predominent cultivatable species (51-61%) in the s amples throughout the 14-day period; with time there was a decreasing percentage of cocci and an increasing percentage of rods. Gram-negativ e cocci and rods increased in proportion with the plaque age (11-37%). Streptococcus spp. were the predominant Gram-positive cocci while Act inomyces were the predominant Gram-positive rods isolated. Fusobacteri um and Capnocytophaga spp. were the two most frequent Gram-negative an aerobic rods cultured. The results compared with those from other anal ogous studies from the West suggest the possibility of interracial dif ferences in supragingival plaque flora. Copyright (C) 1996 Published b y Elsevier Science Ltd.