REMINERALIZING POTENTIAL OF NANO-HYDROXYAPATITE VERSUS NANO-CHITOSAN ON ARTIFICIAL WHITE SPOT LESION IN PERMANENT TEETH

Abstract Background: This study aimed to evaluate and compare the remineralization potential of nano-hydroxyapatite (n-HA) and nano-chitosan (n-CS) on artificial white spot lesion under pH cycling condition. Methods: Eighty premolars were immersed individually in 10 ml of demineralizing solution in separate test tubes at 370C for 15 hours to create an artificial white spot lesion. The demineralized specimens were divided randomly into four groups: (a) n-HA; (b) n-CS; (c) fluoridated toothpaste (positive control); (d) negative control. The remineralization potential of the experimental pastes were evaluated by a quantitative measurement of mineral density using cone beam computerized tomography (CBCT) and a quantitative measurement of surface roughness using the ZYGO Maxim-GP 200 profilometer. The measurements were carried out at five time points: before surface treatment, after lesion preparation, and during treatment protocols at days 7, 14, and 21. The normal distribution of the data was analyzed using the Kolmogorov-Smirnov test. As the data exhibited a normal distribution, a one-way analysis of variance (ANOVA) test was applied to calculate mean differences and compare the study groups. Tukey's post-hoc test was used for pairwise comparisons. Results: CBCT evaluation revealed that n-HA paste gave the best results and recorded the highest mean values of mineral density compared to all groups. Regarding surface roughness results, n-HA paste was the most significant for reducing surface roughness compared to n-CS paste and fluoridated paste. Conclusion: n-HA paste has the highest remineralization potential compared to n-CS paste and fluoridated paste.