Objectives: To evaluate in vitro, the effect of Nano-hydroxyapatite (NHA) toothpaste in comparison with fluoridated toothpaste on remineralization of caries like lesion in the enamel of primary teeth.
Materials and methods: sixty sound primary anterior teeth were coated with nail varnish; leaving squares of 3x3 mm on facial surface then 40 teeth of them were divided into two groups. Group (I) n=20 treated by NHA toothpaste and group (II) n=20 treated by fluoridated toothpaste contains sodium monofluorophosphate (1450 ppm F). They were examined with Vickers Microhardness device. The rest 20 teeth were divided into two groups (III and IV). They were sectioned longitudinally in a labiolingual direction into two equal halves, mesial half not treated (sub group IIIA) and distal half treated by NHA (sub group IIIB). Mesial half not treated (sub group IVA) and distal half treated by fluoridated toothpaste (sub group IVB). Specimens were evaluated quantitatively and qualitatively with Polarized Light Microscope.
Results: The microhardness of teeth significantly decreased following acid exposure but increased again in both groups after exposure to toothpastes. The NHA toothpaste non-significantly increase percent change of microhardness by 1.65 times than Fluoridated toothpaste (p = 0.06). The percent differences in lesion depth between test group IIIB and its control group IIIA was -58.96 ± 9.04, whereas between test group IVB and its control IVA was -56.26 ± 17.43. There was no statistically significant difference between the two values (P=0.67).
Conclusion: NHA and Fluoridated toothpastes are equally effective as remineralizing materials for the enamel.