alidation of a cariogenic biofilm model by evaluating the effect of fluoride on enamel demineralizatio

Author(s)

Marin, Lina M. ^[1] ; Cury, Jaime A. ^[2] ; Siqueira, Walter L. ^[1]

Affiliation

^[1] Univ Saskatchewan, Coll Dent, 105 Wiggins Rd, Saskatoon, SK S7N 5E5 - Canada

^[2] Univ Estadual Campinas, Piracicaba Dent Sch, Av Limeira 901, BR-13414903 Piracicaba, SP - Brazil

• Document type: Journal article
• Source: Journal of Microbiological Methods; v. 192, JAN 2022.
• Web of Science Citations: 0

Abstract

In vitro biofilm models have been extensively used, but only few of the models available to date had been validated in terms of the dose-response effect of anti-caries and/or antimicrobial substances. Additionally, none of the validated models allow the use of microliter volumes of the treatment solutions, needed mainly to test (screen) novel but expensive substances under development. This study aimed at modifying an in vitro cariogenic Streptococcus mutans biofilm model and validating it by assessing the dose-response effect of fluoride on enamel demineralization. S. mutans cariogenic biofilms were developed on saliva-coated enamel slabs previously bonded to acrylic holders fixed to a lid of a culture plate. Biofilms were incubated 8 h/day in culture medium supplemented with 1% sucrose and then overnight in culture medium with glucose 0.1 mM. Biofilms were also treated 2x/day with 2.0 mL of solutions containing 0, 125, 275 and 1250 mu g F/mL (n = 10/group). The replaced culture medium was used to: determine the biofilm acidogenicity; estimate the demineralization of enamel; and monitor the fluoride concentration. At 144 h, biofilms were collected for fluoride concentration analyses, and the fluoride uptake by enamel was determined in each slab. The model showed a dose-response effect of fluoride (R2 = 0.96, p < 0.001) between enamel demineralization and the fluoride concentration of the treatments. Water-soluble and bound biofilm fluoride concentrations (p < 0.007), as well as the firmly-bound fluoride concentration found in enamel (p < 0.0001), increased in a dose-dependent manner. Our model constitutes a validated approach that would allow the assessment of the anticaries potential of novel biotechnological strategies, as in the case of expensive salivary peptides, because it would allow to test the treatment solutions using smaller volumes. (AU)

• FAPESP's process: 17/02692-8 - Effect of statherin and Histatin peptides on cariogenic biofilm and on enamel demineralization
• Grantee: Lina María Marín Gallón
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 14/27034-5 - Caries susceptibility of fluorosed teeth and fluoride effect on its control: in vitro and in situ study
• Grantee: Lina María Marín Gallón
• Support Opportunities: Scholarships in Brazil - Doctorate