Effect of Fluoridated Toothpastes on the Enamel Microhardness of Primary Teeth

Introduction Use of fluoridated toothpaste is the easiest and most common form of applying fluoride. Fluoride absorption can increase tooth microhardness. This study aimed to investigate the changes of primary tooth enamel microhardness following application of KAM, BATH, and CREST pediatric toothpaste. Materials and Methods Microhardness of 45 sound primary molar teeth was measured before the test (step 1). Then, each sample was immersed into 5 mL of 1% stirred citric acid and then in 10 mL of 1% unstirred citric acid for 15 minutes, and the microhardness was remeasured (step 2). Then the samples were immersed in the suspension of three different types of toothpaste (5 g toothpaste + 10 mL artificial saliva). Microhardness was remeasured 10 days later (step 3). Results Demineralization decreases the surface microhardness of enamel (P=0.001) and the surface microhardness recovery in all groups were significant (P=0.001). The best recovery in microhardness after treatment with toothpaste belonged to KAM toothpaste, but there were no significant differences between surface microhardness recovered by three different toothpaste. Conclusion There is no significant difference in microhardness changes after applying KAM (MFP, 200 ppm), BATH (MFP,132 ppm) and CREST (NaF, 500 ppm) toothpaste.