鉄滴相互作用後の一次エナメルの微細硬度および鉱物組成に対する再石灰化治療の評価

This study assessed the effects of remineralizing agents on microhardness and mineral content of primary enamel following iron drop exposure.

In this in vitro study, 36 sound primary anterior teeth were randomly assigned to four groups (n = 9) of (I) casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), (II) fluoride varnish, (III) MI varnish, and (IV) control. The microhardness of specimens was initially measured by a Vickers hardness tester. The specimens were immersed in iron drop solution in a shaker incubator at 37°C for 5 min. They were then rinsed with distilled water, and their microhardness was measured again. The teeth were subsequently split in half. The buccal halves were exposed to the remineralizing agents for 4 h, rinsed with distilled water, and immersed in artificial saliva for 24 h. They were then immersed in a demineralizing solution for 6 h, followed by a remineralizing solution for 18 h at 37°C for 10 days. The final microhardness was measured again. The buccal and lingual halves underwent energy dispersive X-ray spectroscopy for mineral content analysis. Data were analyzed by one-way ANOVA and Tukey test (α = 0.05).

Iron drop exposure significantly decreased, and remineralizing agents significantly increased the microhardness (both p  < 0.001). The three remineralizing agents had no significant difference in enhancement of microhardness (p = 0.493). The four groups had significant differences in Ca, F, and Fe contents after the intervention (p  < 0.05).

Iron drop exposure decreased, and remineralizing agents increased the microhardness and mineral content of primary enamel under in vitro conditions.