Bionic Remineralization of Acidic Etched Enamel Induced by Using Mesoporous Bioactive Glass in Natural Oral Saliva

doi:10.15541/jim20150300

Abstract

Abstract:

Acidic etched enamel was treated with mesoporous bioactive glass (M58S) to induce enamel remineralization in natural oral saliva. By simulated brushing teeth, the M58S was adhered on the enamel surface. Then the samples were rinsed by water and immersed in natural oral saliva for different periods. Characterized by XRD, SEM, FIB-TEM, EDX, SAED, and nanoindentation, the samples showed that a new mineralized phase appeared on the surface of the treated samples after soaking for 6 h. After soaking for 24 h, a compact and homogeneous mineralized layer at the thickness of about 100 nm formed with similar structure to apatite, and ratio of calcium to phosphate which was close to the enamel’s. Under pressure of 300 µN, mineralized layer showed a scratch limited value with microhardness at (3.37±0.62) GPa and elastic modulus at (60.48±4.56) GPa, both close to 75% value of original enamel. These results indicate that mesoporous bioactive glass can rapidly repair etched enamel and prevent teeth from caries. Therefore, the mesoporous bioactive glass may be used as bionic remineralization materials.

Key words: enamel, mesoporous bioactive glass, remineralization

CLC Number:

TQ174

DONG Zhi-Hong, NIE Zhi-Ping, ZHOU Chang-Chun. Bionic Remineralization of Acidic Etched Enamel Induced by Using Mesoporous Bioactive Glass in Natural Oral Saliva[J]. Journal of Inorganic Materials, 2016, 31(1): 88-94.

Figures/Tables 9

Fig. 1 Secondary electron images of sample in the preparing process by FIB-TEM (a) Platinum protected layer deposited on the enamel surface with the total thickness of about 1 μm; (b) Being digged between the protection layers; (c) Being cut a thin slice with thickness of about 1 μm; (d) The already prepared sample

Fig. 2 Small angle XRD pattern and TEM image of M58S

Fig. 3 XRD patterns of etched enamel (a) original enamel (b) and M58S treated and soaked in natural human saliva for 24 h (c)

Fig. 4 SEM images of enamel surface (a) Original enamel; (a1) Etched enamel with adhered M58S; (b) Etched enamel; (b1) Etched enamel without M58S soaked in natural oral saliva for 24 h; (c, d) Etched enamel with adhered M58S soaked in natural oral saliva for 6 h and 24 h, respectively; (c1, d1) Magnified images of (c) and (d), respectively

Fig. 5 TEM image of samples by FIB (a) mineralized layer, (b) enamel matrix, and corresponded Ca/P ratio by EDX

Fig.6 HRTEM image of teeth sample by FIB preparation and selected area electron diffraction (SAED) (a) Mineralized layer of M58S treated for 24 h in natural oral saliva. (b) Enamel matrix.

Fig. 7 Scratch test by nanoindentation machine (a) M58S treated enamel samples soaked in natural oral saliva for 24 h; (b) Enamel original samples

Table1 Mechanical properties detected by nanoindentation

Samples	Hardness value (mean±s.d.)/ GPa	Elastic modulus (mean±s.d.)/ GPa
Original	4.21±0.32	80.30±5.20
24 h treated	3.37±0.62*	60.48±4.56*

Fig. 8 Nanoindentation images of (a) enamel original sample and (b) M58S treated enamel sample soaked in natural oral saliva for 24 h

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