The Anticariogenic Effect of Amine Fluorides on <i>Streptococcus sobrinus</i> and Glucosyltransferase in Biofilms

Abstract

Dental caries is a chronic infectious disease caused by the accumulation of bacterial plaque (biofilm) on tooth surfaces. Antibacterial agents, in addition to other preventive measures, can control dental plaque accumulation. Amine fluorides (AmF) are known anticaries agents for over 30 years. The purpose of our study was to assess the adsorption and desorption of AmF to experimental dental biofilm and to evaluate the effect of AmF on Streptococcus sobrinus 6715 and glucosyltransferase (GTF) activity in experimental dental biofilms. The experimental plaque model used in this study consists of hydroxyapatite beads coated with human saliva (sHA), followed by adsorption of S. sobrinus and synthesis of in situ polysaccharides. Our results show that the viability of S. sobrinus in biofilm decreased as the concentration of AmF and chlorhexidine (CHX) increased. The concentration of AmF and CHX required to kill S. sobrinus adherent to sHA is about 100 times greater than the concentration required to kill the same amount of planktonic bacteria. Adsorption of AmF to surfaces was more than 90% and the desorption of AmF from our experimental model was limited. Pre–adsorption of AmF on the surface increased adhesion of S. sobrinus but also resulted in surface killing of the adsorbed bacteria. At low concentrations AmF increased GTF activity in solution by about 10%, but at concentrations above 0.1 mM it inhibited GTF activity. Inhibition of GTF on the surface required about 100 times more AmF than in solution. Our results show that AmF retains its anticariogenic effects in solution and in biofilm systems.

Antimicrobial Activity of Fluoride and Its in vivo Importance: Identification of Research Questions

“…Preincubation of saliva-coated hydroxyapatite beads with an amine fluoride significantly reduced the number of viable cells in forming an S. sobrinus biofilm whereas preincubation with NaF or chlorhexidine did not [Shani et al, 2000] (fig. 2).…”

“…Popular food and toothpaste additives like benzoate and sodium bicarbonate may have the same effect. BKC is defined as the lowest concentration of the active agent in which a reduction of at least 99% in CFU of biofilm bacteria was observed compared to the control value [data from Shani et al, 2000]. MBC = Minimal bactericidal concentration.…”

“…The system is planktonic, while the dental plaque is a biofilm. Biofilms of Streptococcus sanguis or Streptococcus sobrinus were less susceptible to amine fluorides than planktonic cultures (table 2), but the amine fluorides were more effective inhibitors than sodium fluoride [Embleton et al, 1998;Shani et al, 2000]. Rinsing a saliva-induced biofilm in vitro with a large volume of fluoridated milk (5 ppm fluoride) reduced the numbers of streptococci throughout the biofilm, reaching a 100-fold reduction at the enamel-biofilm interface ( fig.…”

Antimicrobial Agents Used in Endodontic Treatment

“…The stability of this structure could be useful in preventing infection of dentinal tubules and microleakage, as it permanently occludes these tubules and avoids dissolution and disintegration of the smear layer (105). Biofilm inhibitory concentrations for chlorhexidine (300 times) and amine fluoride (75 times) is higher when Streptococcus sobrinus exists as a biofilm in contrast to the minimum bactericidal concentration for planktonic cells (106).…”

Restorati̇f Materyalleri̇n Dental Bi̇yofi̇lm Üzeri̇ne Etki̇leri̇

“…Dişlerde ve restoratif materyallerde dental biyofilm (dental plak) [1][2][3] oluşumunun, çok sayıdaki karyojenik bakteri içeriğiyle birlikte periodontal hastalıkların ve diş çürüklerin gelişiminde önemli rol oynadığı bildirilmiştir [4][5][6] .…”