Effect of starch on the cariogenic potential of sucrose

Abstract

Since in vitro and animal studies suggest that the combination of starch with sucrose may be more cariogenic than sucrose alone, the study assessed in situ the effects of this association applied in vitro on the acidogenicity, biochemical and microbiological composition of dental biofilm, as well as on enamel demineralization. During two phases of 14 d each, fifteen volunteers wore palatal appliances containing blocks of human deciduous enamel, which were extra-orally submitted to four groups of treatments: water (negative control, T1); 2 % starch (T2); 10 % sucrose (T3); and 2 % starch þ 10 % sucrose (T4). The solutions were dripped onto the blocks eight times per day. The biofilm formed on the blocks was analysed with regard to amylase activity, acidogenicity, and biochemical and microbiological composition. Demineralization was determined on enamel by cross-sectional microhardness. The greatest mineral loss was observed for the association starch þ sucrose (P,0·05). Also, this association resulted in the highest lactobacillus count in the biofilm formed (P,0·05). In conclusion, the findings suggest that a small amount of added starch increases the cariogenic potential of sucrose. Among dietary carbohydrates, starch has been pointed out as noncariogenic or slightly cariogenic when used as the sole source of carbohydrate in the diet. This observation has been supported by experiments on dental biofilm acidogenicity (Stephan, 1940;Imfeld, 1977;Lingström et al. 1989), experimental studies with animals (König & Grenby, 1965;Green & Hartles, 1967;Hefti & Schmid, 1979;Bowen et al. 1980), controlled studies in man (Gustaffson et al. 1954), epidemiological data (Marthaler & Froesch, 1967;Fisher, 1968;Newbrun et al. 1980) and in situ experiments (Lingström et al. 1994), which demonstrated that starch is less cariogenic than sucrose.However, while in primitive diets starch was consumed as the main energy source, in contemporary ones it is consumed simultaneously or interspersed with sucrose (Lingström et al. 2000). This combination, which is consumed by both adults and children, may influence dental biofilm composition and consequently dental caries. Thus, a greater prevalence of caries lesions was found in children who consume milk supplemented with a combination of cereal and sucrose (Mattos-Graner et al. 1998). Such observation in human subjects is supported by the results of experimental caries studies in animals (Firestone et al. 1982;Mundorff-Shrestha et al. 1994), suggesting that starch would enhance the cariogenic potential of sucrose.The explanation for the greater cariogenicity of the association of dietary starch with sucrose may reside in the dental biofilm formed. It is well known that the biofilm formed in the presence of sucrose is more cariogenic due to its high concentration of extracellular insoluble polysaccharides (IP), which alter the matrix of the biofilm, making it more porous (Dibdin & Shellis, 1988). These polysaccharides are produced from sucrose by bacterial enzymes named glucosyltransferases....

Epidemiology of dental caries: when structure and context matter

“…This is the case of pure starch-based foods, compared to those based on a mixture of sugar and starch, 22 considering that the latter composition may be more cariogenic than the effect of sucrose. 23 Studies in the United Kingdom have shown that water fluoridation may reduce social inequalities in caries experience, in both deciduous and permanent teeth. 24,25 The notion that water fluoridation is an environmental variable that would not be affected by the position of individuals in the social structure or by income and educational levels 26 would require that it be distributed equally, without any important variation related to consumption sources or fluid intake frequency in different population groups; however, this cannot always be ensured.…”

Structural and Molecular Basis of the Role of Starch and Sucrose in Streptococcus mutans Biofilm Development

“…In summary, our data provide insight into how starch and sucrose in combination are potentially more cariogenic than either compound alone in vivo (1,10,30) and also show that the composition of diet in association with specific host-pathogen interactions can modulate the development of biofilms by S. mutans with enhanced virulence. Further in vitro and in vivo studies using both parental strains of S. mutans and mutant strains of S. mutans (defective in gtfB or TCS) in the presence of microorganisms that bind amylase (e.g., Streptococcus gordonii) should elucidate in more detail the structural and molecular mechanisms in a multispecies system.…”

“…Starches are an important source of fermentable carbohydrate and are usually consumed simultaneously with sucrose in modern societies. The combination of starch and sucrose is highly cariogenic in vivo (1,10,33) and may enhance the pathogenicity of biofilms in humans (30).…”

Two Closely Related ABC Transporters in Streptococcus mutans Are Involved in Disaccharide and/or Oligosaccharide Uptake

“…Therefore, a variety of dietary or host-derived carbohydrates may support S. mutans growth and contribute to caries. Because starch is a major dietary carbohydrate in modern societies, it is considered a potential contributor to caries, either alone or in combination with sucrose (5,21,27). Saliva contains an abundance of ␣-amylase, an enzyme that degrades starch to yield maltose and maltodextrins [linear ␣-(1,4)-linked D-glucose polymers] (16).…”