| Sign In to gain access to subscriptions and/or personal tools. |
Mutans Streptococci and Non-mutans Streptococci Acidogenic at Low pH, and in vitro Acidogenic Potential of Dental Plaque in Two Different Areas of the Human DentitionDepartments of Oral Microbiology, Forsyth Dental Center, 140 The Fenway, Boston, Massachusetts 02115
Departments of Oral Microbiology, Forsyth Dental Center, 140 The Fenway, Boston, Massachusetts 02115
Department of Clinical Trials and Human Experimentation, Forsyth Dental Center, 140 The Fenway, Boston, Massachusetts 02115
Department of Clinical Trials and Human Experimentation, Forsyth Dental Center, 140 The Fenway, Boston, Massachusetts 02115 Samples of human dental plaque were obtained from sound tooth surfaces in the lower anterior and upper posterior areas of each of 11 subjects with various degrees of caries experience. Both types of plaque were compared for: (1) their pH-loweringpotential [pH at 10 and 60 min after sugar addition and the pH drop between 0 and 10 min (delta pH)] with an in vitro method involving dispersed plaque suspensions and excess glucose supply; (2) the proportions ofmutans streptococci; and (3) the distribution of the predominant non-mutans streptococci according to their final pH in glucose broth. Compared with plaque from the lower anterior area, plaque from the upper posterior area exhibited a significantly higher pH-lowering potential, i.e., a lower pH at 10 and 60 min and a greater delta pH and significantly higher levels of mutans streptococci. The final pH values for the non-mutans streptococci exhibited a wide range from about 4.4 to over 5.0. The proportions of such organisms designated as capable of acidogenesis at low pH (final pH < 4.6), whether expressed as a percentage of the total non-mutans streptococci or of the total plaque flora, were significantly increased in plaque from the upper posterior area. The proportions of non-mutans streptococci capable of acidogenesis at low pH in plaque from the upper posterior area were also significantly increased, with decreasing pH values at 10 and 60 min. The findings strengthen the link between the capacity of the plaque flora for acidogenesis at a low pH and its pH-loweringpotential as well as the role of bacterial acidogenesis at a low pH as an oral ecological determinant.
Journal of Dental Research, Vol. 70, No. 12,
1503-1507 (1991) This article has been cited by other articles:
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||





