Effect of Different Fluoridated Toothpastes on the Enamel Microhardness of Primary Teeth

Using fluoridated toothpaste is the most feasible and common form of applying fluoride. Fluoride absorption could increase tooth microhardness. Therefore, the present study aimed to investigate the changes of primary tooth enamel microhardness following KAM, BATH, and CREST pediatric toothpaste use.

In total, 45 healthy primary molar teeth were randomly divided into three 15-membered groups. The microhardness of samples was measured before the test (step 1). Each sample was immersed into 5mL of 1% stirred citric acid; then, in 10 mL of 1%, unstirred citric acid for 15 minutes, and microhardness was re-measured (step 2). Then, the samples were immersed in the suspension of three different toothpaste types (5 g toothpaste +10 mL artificial saliva). Microhardness was re-measured 10 days later (step 3). Analysis of Variance (ANOVA) and Tukey test were applied for statistical analysis.

Demineralization decreased the surface microhardness of enamel (P=0.001). Moreover, the surface microhardness recovery was significant in all groups (P=0.001). The greatest recovery in microhardness after the treatment with toothpastes belonged to KAM toothpaste; however, there were no significant differences between surface microhardness produced by the three toothpastes.

There was no significant difference in microhardness changes after applying KAM (MFP, 200 ppm), BATH (MFP, 132 ppm) and CREST (NaF, 500 ppm) toothpastes. Thus, the use of Iranian pediatric toothpastes, which are inexpensive and have lower concentration of fluoride, are recommended.