Anticaries activity of egg ovalbumin in an experimental caries biofilm model on enamel and dentin

Limited evidence suggests a putative inhibitory effect of dietary proteins on demineralization during the carious process. The aim was to explore a potential anticaries activity of the egg protein ovalbumin on a relevant in vitro approach.

Biofilms of Streptococcus mutans UA159 were formed on saliva-coated enamel and dentin bovine slabs. Biofilms were challenged with 10% sucrose followed by either a 200 μg/mL solution of ovalbumin or 1:10, 1:100, and 1:1000 (v/v) serial dilutions of that ovalbumin solution, for the entire length of the experiment. Biofilms exposed to 10% sucrose followed only by 0.9% NaCl served as caries-positive control. Once completed the experimental phase, biofilms were analyzed for biomass, viable bacteria, and polysaccharide formation. Final surface hardness (SH) was obtained to calculate %SH loss (demineralization). Two independent experiments were conducted, in triplicate. Data were analyzed by ANOVA and a post hoc test at the 95% confidence level.

A reduction (p < 0.05) in biomass and extracellular polysaccharide formation, but not in the number of viable cells, was observed for both dental substrates. All ovalbumin concentrations tested showed lower demineralization than the positive control (p < 0.05), in a dose-dependent manner. The highest concentration showed a reduction in the %SH loss of about 30% for both enamel and dentin.

Ovalbumin may counteract the cariogenic effect of sugars. If these findings are clinically confirmed, novel preventive approaches for caries are warranted.