Anti-bacterial Determinants of Stannous Fluoride

Abstract

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.

Effect of Fluoride-Containing Toothpastes on Enamel Demineralization and <b><i>Streptococcus mutans</i></b> Biofilm Architecture

“…Regrowth could have been slowed down by residual CHX bound to dead cells and enamel [Baca et al, 2012;Babu and Garcia-Godoy, 2014]. Stannous can alter S. mutans growth and metabolism [Mayhew and Brown, 1981;Camosci and Tinanoff, 1984] as well as inhibit bacterial adhesion/plaque formation and acid production [Tinanoff et al, 1976;Skjorland et al, 1978], potentially retarding biofilm development and altering its architecture, as observed in our system ( fig. 3 ).…”

“…Because the antibacterial activity of stannous ions is well known [Mayhew and Brown, 1981;Camosci and Tinanoff, 1984;Zameck and Tinanoff, 1987], its presence in the SnF 2 -containing toothpaste suggests that it is the responsible ingredient for the antimicrobial/antibiofilm effect observed with this formulation ( fig. 3 ).…”

“…Although there is not enough clinical evidence to demonstrate that SnF 2 -based toothpaste is more effective than NaF-based toothpaste for caries control [Marinho et al, 2003] , it has been suggested that SnF 2 toothpaste could be superior [Faller et al, 1995]. This is because stannous has been indicated to have antimicrobial activity [Mayhew and Brown, 1981;Camosci and Tinanoff, 1984] and can reduce acid and glucan production [Ferretti et al, 1982;Zameck and Tinanoff, 1987]. On the other hand, NaF has been shown in vivo [Svanberg and Rolla, 1982] and in vitro to lack a substantial antimicrobial effect when simulating mouthrinse or toothpaste use.…”

Effects on Gingivitis of Two Different 0.4% SnF2 Gels

“…The error of measurement reported for both clinical examiners in this paper also corresponds with those values previously reported (Glavind and Loe, 1967 (Tinanoff, 1985). Because the antibacterial activity of SnF2 appears to be related to the availability of Sn2+ ions Camosci and Tinanoff, 1984;Attramadal and Svatun, 1980), these differences may be of significance when these gels are used for control of gingivitis. Camosci and Tinanoff (1984) also showed that other heavy metal ions and Sn3+ ions are not as effective as the Sn2+ ion, and that the mechanism for the bactericidal activity of Sn2+ appeared to be related to intracellular retention of tin by the bacteria.…”

“…These effects appear to be related to the availability of the Sn2+ ion rather than the F-ion (Camosci and Tinanoff, 1984). Other clinical reports have demonstrated that topically applied SnF2 is associated with reduction of supragingival plaque, motile subgingival plaque micro-organisms, gingivitis, and pocket depth (for review, see Boyd et al, 1985).…”