title: Enamel and dentine demineralization by a combination of starch and sucrose in a biofilm - caries model.
abstract: Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day) to one of the following treatments: 0.9% NaCl (negative control), 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose). To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day) the culture medium pH. After 4 (dentine) or 5 (enamel) days of growth, biofilms (n = 9) were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001) on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.
authors.affiliation: University of Campinas - UNICAMP, Piracicaba Dental School, Department of Physiological Sciences, Piracicaba, SP, Brazil.
authors.forename: Juliana Nunes
authors.initials: JN
authors.lastname: Botelho
authors.affiliation: University of Talca - UTALCA, Department of Oral Rehabilitation, Cariology Unit, Talca, Región del Maule, Chile.
authors.forename: Mario
authors.initials: M
authors.lastname: Villegas-Salinas
authors.affiliation: University of Talca - UTALCA, Department of Oral Rehabilitation, Cariology Unit, Talca, Región del Maule, Chile.
authors.forename: Pía
authors.initials: P
authors.lastname: Troncoso-Gajardo
authors.affiliation: University of Talca - UTALCA, Department of Oral Rehabilitation, Cariology Unit, Talca, Región del Maule, Chile.
authors.forename: Rodrigo Andrés
authors.initials: RA
authors.lastname: Giacaman
authors.affiliation: University of Campinas - UNICAMP, Piracicaba Dental School, Department of Physiological Sciences, Piracicaba, SP, Brazil.
authors.forename: Jaime Aparecido
authors.initials: JA
authors.lastname: Cury
mesh_terms: D000818:Animals; D018441:Biofilms / Q000254:growth & development*; D002326:Cariogenic Agents / Q000737:chemistry*; D002417:Cattle; D015169:Colony Count, Microbial; D003743:Dental Enamel / Q000737:chemistry* / Q000382:microbiology; D003804:Dentin / Q000737:chemistry* / Q000382:microbiology; D019422:Dietary Sucrose / Q000737:chemistry*; D006801:Humans; D012016:Reference Values; D012463:Saliva / Q000737:chemistry / Q000382:microbiology; D013213:Starch / Q000737:chemistry*; D018709:Statistics, Nonparametric; D013295:Streptococcus mutans / Q000254:growth & development; D013997:Time Factors; D017001:Tooth Demineralization / Q000209:etiology* / Q000382:microbiology; D055815:Young Adult
chemical_list: D002326:Cariogenic Agents; D019422:Dietary Sucrose; D013213:Starch