A COMPARISON OF THE DETACHMENT OF AN ADHERING ORAL STREPTOCOCCAL STRAIN STIMULATED BY MOUTHRINSES AND A PREBRUSHING RINSE

The effects of two mouthrinses, Hibident(R) and Scope(R), and a pre-br ushing rinse, Plax(R), on the detachment of an oral bacterium adhering to enamel, with and without a salivary conditioning film, were compar ed. Furthermore, the influence of the hydrophobicity of the substratum on the detachment of adhering microorganisms as stimulated by the ora l rinses was studied. All experiments were carried out in a parallel p late flow chamber with Streptococcus sobrinus HG 1025 adhering to enam el, hydrophilic glass and dichlorodimethylsilane-coated, hydrophobic g lass. Perfusion of the flow chamber with the two mouthrinses did not s timulate any significant detachment of adhering S. sobrinus HG 1025, w hereas perfusion with the pre-brushing rinse stimulated up to 100% det achment. Moreover, the pre-brushing rinse Plax(R) was more effective i n stimulating bacterial detachment from salivary conditioning films th an from bare substrata. Plax(R), and possibly to a lesser extent also Scope(R), weakened the bond between adhering S. sobrinus HG 1025 and t he substrata, thereby facilitating removal of adhering cells during hi gh shear, as exerted here by the passage of a liquid-air interface thr ough the chamber and as occurring in vivo by eating, speaking, drinkin g or swallowing. It is hypothesized that the controversies over the cl inical efficacies of Plax(R) may be due to the inability of its, other wise effective, detergent system to penetrate the plaque and stimulate detachment of the linking film, i.e. the initially adhering bacteria.