Formulation and Evaluation of Characteristics, Remineralization Potential, and Antimicrobial Properties of Toothpaste Containing Nanohydroxyapatite and Nanosilver Particles: An In Vitro Study

Aim and objectives: The current study is aimed to evaluate the antimicrobial and remineralizing properties of toothpaste containing nanosilver and nanohydroxyapatite (NH-NS TP).

Materials and methods: The toothpaste was prepared by incorporating NH-NS TP into a toothpaste base. Following this, a physicochemical analysis of the prepared toothpaste was carried out. The toxicity against human gingival fibroblast (HGF-1) cells was assessed. The antimicrobial activity of the toothpaste was evaluated against Streptococcus mutans and Escherichia coli using the disk diffusion method. Subsequently, 15 selected human premolar teeth extracted for orthodontic purposes were used to measure the remineralization potential. The surfaces of the selected teeth were demineralized using a prepared demineralizing solution [323.4 mg of calcium chloride (CaCl₂), M450 µL of calcium acetate (CH₃COO)₂Ca, 300 mg of potassium dihydrogen phosphate (KH₂PO₄) at pH 4.4-4.7] for 72 hours and were subjected to a toothbrush simulator applying the prepared toothpaste. The remineralization potential was evaluated by measuring the microhardness of the enamel surface before and after treatment with the toothpaste. Further, the remineralization potential was assessed based on scanning electron microscopy (SEM) imaging accompanied by energy-dispersive X-ray spectroscopy.

Results: The results showed that the NH-NS TP had significantly greater antimicrobial activity compared to the control toothpaste and no toxicity against HGF-1 up to 40 µg. Approximately, 7-9 mm inhibition zone against S. mutans and 4-6 mm inhibition against E. coli was achieved. Additionally, the toothpaste significantly increased (31.4%) the microhardness of the enamel surface, indicating its potential for remineralization. The SEM images revealed the presence of regular deposits, mostly pertaining to the demineralized spots, resulting in a regained smooth surface. Following this, physicochemical analysis of the prepared toothpaste was carried out, resulting in a pH of 7.38 and showing good extrusion, frothing, and organoleptic properties. Additionally, the toothpaste significantly increased the microhardness of the enamel surface, further indicating its potential for remineralization.

Conclusion: NH-NS TP may provide a promising approach for improving oral health by enhancing antimicrobial efficacy and promoting enamel remineralization, while exhibiting reduced toxicity.

How to cite this article: Sevagaperumal A, Joel JR Periyasamy S. Formulation and Evaluation of Characteristics, Remineralization Potential, and Antimicrobial Properties of Toothpaste Containing Nanohydroxyapatite and Nanosilver Particles: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(6):630-636.