Variable colonization by oral streptococci in molar fissures of monoinfected gnotobiotic rats.

Germfree Sprague-Dawley rats, fed a high-sucrose diet, were monoinfected with strains of Streptococcus mitis, Streptococcus sanguis, and Streptococcus mutans. Viable cell recoveries from six molar teeth, considered to reflect mainly bacterial colonization of intact fissures, were in the order of 10(6), 10(7), and 10(8) CFU, respectively. Some of the implications of the variation of bacterial plaque-forming ability in the rat model are discussed.