Effect of Human Streptococcus Strain GS-5 on Caries and Alveolar Bone Loss in Conventional Mice and Rats

¹ Forsyth Dental Center, Boston, Massachusetts

Human streptococcus strain GS-5 was made resistant to 1 mg./ml. of streptomycin and then implanted by inoculation into the mouths of mice and rats in which microbiota had been suppressed by penicillin administered in the diet. Organisms were established in the mouths of the rats in 29 of 30 samples taken at three time intervals, but not in the mouths of mice in any of 30 samples taken at the same three intervals. Four of 10 rats harboring the human streptococcus developed dental caries, whereas control rats did not. The rate of alveolar bone loss was significantly greater in rats inoculated with the human streptococcus than in the uninoculated controls.