Erosive effects of beverages in the presence or absence of caries simulation by acidogenic challenge on human primary enamel: an in vitro study.

AIM: To evaluate in vitro the erosive effects of beverages in the presence or absence of caries simulation (acidogenic challenge) on the microhardness of primary enamel.
METHODS: Forty human primary teeth were submitted to the erosive effects: 3 × 20-min-long daily immersion in fresh orange juice (orange group), strawberry yogurt drink (yog group), or cola soft drink (cola group) separately or in combination with acidogenic challenge (pH cycling for 10 days). Specimens were also submitted to acidogenic challenge alone, and in the negative control group specimens were not submitted to any treatment. Mineral loss was evaluated by cross-sectional microhardness determination. The data (Knoop hardness numbers, KHN) were subjected to 2-way analysis of variance and Tukey's post hoc test (α = 0.05%).
RESULTS: All the test beverages significantly reduced the sample cross-sectional enamel hardness (KHN ± SD, 235.93 ± 18.15, 257.23 ± 21.79, and 253.23 ± 13.86 in the orange, yog, and cola groups, respectively) compared to samples in the negative control group (290.27 ± 3.92). In vitro acidogenic challenge exacerbated the mineral loss induced by all beverages (166.02 ± 4.28, 190.43 ± 17.55, and 198.39 ± 21.39 in the orange, yog, and cola groups combined to acidogenic challenge, respectively) compared to acidogenic challenge alone.
CONCLUSIONS: All beverages exhibited erosive effects on primary enamel. Simulated caries challenge considerably exacerbated the enamel softening of primary teeth.