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Comparative scanning electron microscopy/energy-dispersive X-ray study of nano-hydroxyapatite toothpaste in correlation of remineralization

Abdillah Imron Nasution, Basri A Gani


Background: Nano-hydroxyapatite (n-HAp) is one of the most biocompatible and bioactive materials and has gained a wide attention in medicine and dentistry. Recently, a few reports have shown that n-HAp has some potential to repair dental enamel, but poor explanation is available regarding the effect of n-HAp to fluor, Ca/P ratio, and sodium silicate values on enamel surface in correlation with remineralization time. Aim: The aim is to study the comparative assessments of enamel surface morphology and descriptive analysis of fluoride, Ca/P ratio, and sodium silicate after immersed in four different solutions in 90, 180, 270, and 360 min. Materials and Methods: The crowns of 16 teeth specimens were decoronated from the roots using a water-cooled diamond bur and divided into four groups at random, and separately, based on four different solutions: Solution 1 is NaCl 0.9% with as much as 0.15 ml as control, solution 2 is a demineralized solution which is consisting of 0.3% citric acid at pH 3.25 - maintained with the use of sodium hydroxide in 10 ml as demineralization group, solution 3 is n-HAp toothpaste (4.8 g dissolved in water as much as 14.4 ml) + 0.15 ml NaCl 0.9% as n-HAp1 group, and solution 4 is n-HAp toothpaste + demineralization solution as n-HAp2 group. The whole group was put into an incubator at 37°C after being centrifuged at 70 rpm for 3 min and then washed in distilled water for 2 min, dried at room temperature, and visualized by scanning electron microscopy/energy dispersive X-ray at 1.2 kV. Conclusion: The present study concludes that n-HAp toothpaste does not provide any preservative remineralization potential on enamel surface. Clinical Significance: Mineral loss in demineralization enamel was not uniform and varied in different parts of the lesions. Duration of acid exposure times has been shown to decreasing the ability of toothpaste to restoring demineralization conditions. Under normal conditions, the best time to brush one’s teeth with n-Hap toothpaste is every 6 h while under the demineralization condition is 3.5 h.


Ca/P ratio; Fluor; Nano-hydroxyapatite; Scanning electron microscopy/energy-dispersive X-ray; Sodium silicate

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