title: Frequency of sucrose exposure on the cariogenicity of a biofilm-caries model.
abstract: OBJECTIVE
  Although sucrose is considered the most cariogenic carbohydrate in the human diet, the question of how many exposures are needed to induce damage on the hard dental tissues remains unclear. To approach this question, different frequencies of daily sucrose exposure were tested on a relevant biological caries model.
  
  
  METHODS
  Biofilms of the Streptococcus mutans were formed on enamel slabs and exposed to cariogenic challenges with 10% sucrose for 5 min at 0, 1, 3, 5, 8, or 10 times per day. After 5 days, biofilms were retrieved to analyze biomass, protein content, viable bacteria, and polysaccharide formation. Enamel demineralization was evaluated by percentage of microhardness loss (percentage surface hardness loss [%SHL]).
  
  
  RESULTS
  Biomass, protein content, polysaccharide production, acidogenicity of the biofilm, and %SHL proportionally increased with the number of daily exposures to sucrose (P < 0.05). One daily sucrose exposure was enough to induce 20% more demineralization than the negative unexposed control. Higher frequencies induced greater demineralization and more virulent biofilms, but eight and ten exposures were not different between them in most of the analyzed variables (P > 0.05).
  
  
  CONCLUSIONS
  Higher sucrose exposure seems to increase cariogenicity, in a frequency-dependent manner, by the modification of bacterial virulent properties.
authors.affiliation: Department of Oral Rehabilitation, Cariology Unit, University of Talca, Talca, Chile.
authors.forename: Natalia
authors.initials: N
authors.lastname: Díaz-Garrido
authors.affiliation: Oral Biology and Biochemistry Laboratory, Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago, Chile.
authors.forename: Carla
authors.initials: C
authors.lastname: Lozano
authors.affiliation: Department of Oral Rehabilitation, Cariology Unit, University of Talca, Talca, Chile.|Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), University of Talca, Talca, Chile.
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Giacaman
keywords: Caries; Streptococcus mutans; diet; nutrition; sucrose; sugar