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Relationship Between Volume and Streptococcal Population in Dental Plaque
G. CHARLTON, R. G. SCHAMSCHULA, and B. BLAINEY Department of Bacteriology, University of Sydney, and Institute of Dental Research, Sydney 2006, Australia There has been an increasing interest in studying and comparing the bacterial populations, in particular the streptococcal population, of dental plaque collected from specific sites. While collecting plaque from a small standard area, we observed a great variation in the volume of plaque obtained. The present study was undertaken to determine if the streptococcal population changed with the volume of plaque. Plaque was collected from a clinically sound area 5.3 mm2, centered I mm incisally from the gingival margin of the labial surface of the upper right permanent latetal incisor of 130 children in Sydney, Australia. The volume of each sample was measured immediately and the samples cultured on Mitis-Salivarius agar, by the methods of Schamschula and Charlton (Aust Dent J 16: 77, 1971) . The streptococcal colonies were counted and classified into several groups according to their colony structure, but only those resembling Streptococcus sanguis and S mnutans were considered in this report. The streptococcal density was related inversely to plaque volume. A correlation coefficient of -0.44 was found between the square root of the volume and the natural logarithm of the density of streptococcal colony-forming units (CFU) in plaque (N=130, P
Relationship Between Volume and Streptococcal Population in Dental Plaque
G. CHARLTON, R. G. SCHAMSCHULA, and B. BLAINEY Department of Bacteriology, University of Sydney, and Institute of Dental Research, Sydney 2006, Australia There has been an increasing interest in studying and comparing the bacterial populations, in particular the streptococcal population, of dental plaque collected from specific sites. While collecting plaque from a small standard area, we observed a great variation in the volume of plaque obtained. The present study was undertaken to determine if the streptococcal population changed with the volume of plaque. Plaque was collected from a clinically sound area 5.3 mm2, centered I mm incisally from the gingival margin of the labial surface of the upper right permanent latetal incisor of 130 children in Sydney, Australia. The volume of each sample was measured immediately and the samples cultured on Mitis-Salivarius agar, by the methods of Schamschula and Charlton (Aust Dent J 16: 77, 1971) . The streptococcal colonies were counted and classified into several groups according to their colony structure, but only those resembling Streptococcus sanguis and S mnutans were considered in this report. The streptococcal density was related inversely to plaque volume. A correlation coefficient of -0.44 was found between the square root of the volume and the natural logarithm of the density of streptococcal colony-forming units (CFU) in plaque (N=130, P
