Figure 8. In vitro pH response of pooled dental plaque to which (a)S. mutans GS-5 (serotype c), (b)S. sanguis II (i.e., oralis) isolated from saliva, (c)L. casei, or (d)A. viscosus had been added. Incubation mixtures were prepared as in Fig. 7. All four strains are generally considered to be cariogenic. Note that none has pH-raising capability (Table). In each case, the Stephan pH response was made more acidogenic with their addition (from Wijeyeweera and Kleinberg, 1989a).