J Korean Acad Conserv Dent.  2007 Mar;32(2):151-161. 10.5395/JKACD.2007.32.2.151.

The effect of the pH of remineralized buffer solutions on dentin remineralization

• Kim SC
• Roh BD
• Jung IY
• Lee CY

• KMID: 2175848
• DOI: http://doi.org/10.5395/JKACD.2007.32.2.151

Abstract

Dental caries is the most common disease in the oral cavity. However, the mechanism and treatment of dental caries is not completely understood since many complex factors are involved. Especially the effect of pH on remineralization of early stage of dental caries is still controversial. In this study, dental caries in dentin was induced by using lactic acidulated buffering solutions and the loss of inorganic substance was measured. Also decalcified specimens were remineralized by three groups of solution with different pH (group of pH 4.3, 5.0, and 5.5). Then, the amount and the area of inorganic substance precipitation was quantitatively analyzed with microradiograph. Also a qualitative comparison of the normal phase, the demineralized phase, and the remineralized phase of hydroxyapatite crystal was made under SEM. The results were as follows; 1. In microradiograghic analysis, as the pH increased, the amount of remineralization in decalcified dentin tended to increase significantly. As the pH decreaced, deeper decalcification, however, occurred along with remineralization. The group of pH 5.5 had a tendency to be remineralized without demineralization (p < 0.05). 2. In SEM view, the remineralization in dentine caries occurred from the hydroxyapatite crystal surface surrounding the mesh of organic matrix, and eventually filled up the demineralized area. 3. 5 days after remineralization, hydroxyapatite crystal grew bigger with deposition of inorganic substance in pH 4.3 and 5.0 group, and the crystal in the remineralized area appeared to return to normal. After 10 days, the crystals in group of pH 4.3 and 5.0, which grew bigger after 5 days of remineralization, turned back to their normal size, but in group of pH 5.5, some crystals were found to double their size. In according to the results of this experiment, the decalcifying and remineralizing process of dentine is neither simple nor independent, but a dynamic process in which decalcification and remineralization occur simultaneously. The remineralization process occurred from the hydroxyapatite crystal surface.

Keyword

Remineralization; Dentin; pH; Demineralization; Enamel; Scanning electron microscope

MeSH Terms

Dental Caries
Dental Enamel
Dentin*
Durapatite
Hydrogen-Ion Concentration*
Mouth
Durapatite

Figure

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  Figure 1 Quantitative mineral density change of dentin during de- & remineralization of pH 4.3 group.

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  Figure 2 Quantitative mineral density change of dentin during de- & remineralization of pH 5.0 group.

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  Figure 3 Quantitative mineral density change of dentin during de- & remineralization of pH 5.5 group.

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  Figure 4 SEM micrograph of normal dentin (× 100,000).

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  Figure 5 SEM micrograph of the demineralized dentin (× 100,000).

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  Figure 6 SEM micrograph of the remineralizeddentin of pH 4.3 group at 30 µm area from the surface layer (× 100,000).

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  Figure 7 SEM micrograph of the demineralized dentin of pH 4.3 group at 70 µm area from the surface layer (× 100,000).

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  Figure 8 SEM micrograph of the remineralized dentin of pH 5.0 group at 50 µm area from the surface layer (× 100,000).

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  Figure 9 SEM micrograph of the demineralized dentin of pH 5.0 group at 70 µm area from thesurface layer (× 100,000).

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  Figure 10 SEM micrograph of the remineralized dentin of pH 5.5 group at 40 µm area from the surface layer (× 100,000).

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  Figure 11 SEM micrograph of the remineralized dentin of pH 5.5 group at 70 µm area from the surface layer (× 100,000).

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  Figure 12 SEM micrograph of the remineralized dentin of pH 4.3 group at 30 µm area from the surface layer (× 100,000).

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  Figure 13 SEM micrograph of the remineralized dentin of pH 4.3 group at 70 µm area from the surface layer (× 100,000).

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  Figure 14 SEM micrograph of the remineralized dentin of pH 5.0 group at 50 µm area from the surface layer (× 100,000).

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  Figure 15 SEM micrograph of the remineralized dentin of pH 5.0 group at 70 µm area from the surface layer (× 100,000).

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  Figure 16 SEM micrograph of the remineralized dentin of pH 5.5 group at 40 µm area from the surface layer (× 100,000).

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  Figure 17 SEM micrograph of the remineralized dentin of pH 5.5 group at 70 µm area from the surface layer (× 100,000).

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