Comparative evaluation of the effects of human breast milk and plain and probiotic-containing infant formulas on enamel mineral content in primary teeth: an in vitro study.

Abstract

This study quantitatively investigated the changes in enamel mineral content of primary teeth after immersion in human breast milk and plain and probiotic-containing infant formulas. Thirty-six sound primary anterior teeth were collected and assessed for mineral content (calcium and phosphorus content in wt%) using scanning electron microscope attached with energy-dispersive X-ray analyser (SEM-EDXA). In order to create a microbial-induced caries model, the enamel surfaces of the teeth were inoculated with mutans streptococci and then each tooth was randomly assigned to one of three groups: human breast milk, plain infant formula or probiotic-containing infant formula (n = 12) each. Teeth were then soaked in the designated type of milk, and the solutions were replenished every day for 1week after which the mineral content was measured again using SEM-EDXA. Wilcoxon signed-rank test was used to study the changes by time within each group, and the significance level was set at P ≤ 0.05. Treatment of enamel surface with breast milk has significantly increased mean Ca wt%, while no significant changes were detected in mean P wt%. On the other hand, when primary teeth were soaked in plain or probiotic-containing infant formulas, both mean values of both Ca and P wt% significantly decreased. In conclusion, whereas breast milk might confer some protective effect against enamel demineralisation, infant formulas whether plain or supplemented with some probiotics might promote loss of minerals from enamel surface.