Journal of Dental Research, Vol 63, 1121-1125, Copyright © 1984 by International & American Associations for Dental Research Online Journals
Anti-bacterial determinants of stannous fluoride
D. A. Camosci and N. Tinanoff
The growth of bacteria on stainless steel wires was used as a model to
investigate which properties of SnF2 produced anti-bacterial effects
against S. mutans. Wire-adherent bacteria were exposed for one min, twice a
day, to various fluoride or control compounds having similar ions, pH,
valence, or atomic weights. After two days, the thickness of adherent
bacteria was scored visually, and the decrease in pH of the growth medium
was determined. Bacteria from each wire were then dried, weighed, and
analyzed for metal content. Electron microscopy and electron microprobe
were used to identify the location of heavy metal deposits in the bacteria.
Only SnF2 dramatically altered S. mutans growth and metabolism, and this
anti-bacterial effect was associated with a large uptake of tin into the
bacterial cells. The fluoride salts of sodium, lead, zinc, and copper had
little influence on S. mutans growth in this test system. The pH of the
various fluoride salts or controls generally had no effect on the activity
of the test compounds, except for the noted inactivation of SnF2 at
elevated pH's. Since SnF4 did not alter the growth or metabolism of S.
mutans, a unique property of SnF2--possibly the reactivity in an aqueous
environment--may be responsible for its anti-bacterial properties.
