EFFECT OF INFANT FORMULAS BASED ON LACTOSE AND/OR MALTODEXTRINS ON CARIES DEVELOPMENT

Infant formulas may contain lactose, maltodextrins or a mixture of these carbohydrates that are fermented by dental biofilm to acids and per se can provoke enamel demineralization. In addition, if they were sweetened with sucrose higher demineralization might occur. Therefore, using the cariogenic Streptococcus mutans model, we evaluated the effect of infant formulas, having or not sucrose added, on enamel demineralization. Biofilms of S. mutans UA159 were formed on saliva-coated bovine enamel of surface hardness (SH) known. Infant formulas contained 8.0% lactose, 7.2% maltodextrin or a mixture of 6.2% lactose and 2.1% maltodextrin as the carbohydrate source. Biofilms were exposed 8 times a day, for 3-min, to one of the 8 treatments (n=9): only purified water (negative control); only 10% sucrose solution (positive control); and the three formulas prepared in water or in a 10% sucrose solution. The effect of salivary amylase on starch-products was considered, as previously described. After 96 h of formation, biofilms were collected to assess viable cells, biomass, and extracellular polysaccharides (EPS). Enamel percentage of SH loss (%SHL) was evaluated as an indicator of demineralization. The results were statistically analyzed by two-way ANOVA and Tukey's test (α=5%). In the absence of sucrose (mean±SD;n=9), exposure to the formulas presented higher %SHL (lactose=5.0±1.6; maltodextrin=6.1±1.7; lactose and maltodextrin=5.6±2.2) compared to negative control (0.6±0.3) (p>0.05). Adding sucrose to formulas increased demineralization (p<0.05), with infant formula based maltodextrin (34.9±13.6) similar to the positive control (31.5±9.2) (p>0.05), and higher than lactose (13.0±9.9) and lactose and maltodextrin (16.9±7.5) (p<0.05). Higher amounts of biomass and insoluble EPS were found when sucrose was added; maltodextrin group presented higher values when compared to the others (p<0.05). In conclusion, infant formulas have cariogenic potential to cause enamel demineralization, which is higher when sucrose is added to the formulas, mainly for formulas containing maltodextrins.