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Recovery of crystallographic texture in remineralized dental enamel.

Siddiqui S, Anderson P, Al-Jawad M - PLoS ONE (2014)

Bottom Line: Little is known about the crystallographic effects of demineralization and remineralization.Remineralization restores the texture to the original level seen in healthy enamel and restores mineral density.The results also showed that remineralization promotes ordered formation of new crystallites and growth of pre-existing crystallites which match the preferred orientation of healthy enamel.

View Article: PubMed Central - PubMed

Affiliation: Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom.

ABSTRACT
Dental caries is the most prevalent disease encountered by people of all ages around the world. Chemical changes occurring in the oral environment during the caries process alter the crystallography and microstructure of dental enamel resulting in loss of mechanical function. Little is known about the crystallographic effects of demineralization and remineralization. The motivation for this study was to develop understanding of the caries process at the crystallographic level in order to contribute towards a long term solution. In this study synchrotron X-ray diffraction combined with scanning electron microscopy and scanning microradiography have been used to correlate enamel crystallography, microstructure and mineral concentration respectively in enamel affected by natural caries and following artificial demineralization and remineralization regimes. In particular, the extent of destruction and re-formation of this complex structure has been measured. 2D diffraction patterns collected at the European Synchrotron Radiation Facility were used to quantify changes in the preferred orientation (crystallographic texture) and position of the (002) Bragg reflection within selected regions of interest in each tooth slice, and then correlated with the microstructure and local mineral mass. The results revealed that caries and artificial demineralization cause a large reduction in crystallographic texture which is coupled with the loss of mineral mass. Remineralization restores the texture to the original level seen in healthy enamel and restores mineral density. The results also showed that remineralization promotes ordered formation of new crystallites and growth of pre-existing crystallites which match the preferred orientation of healthy enamel. Combining microstructural and crystallographic characterization aids the understanding of caries and erosion processes and assists in the progress towards developing therapeutic treatments to allow affected enamel to regain structural integrity.

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Scanning microradiography area scans showing the relative mineral density distribution of a) artificially demineralized lesion, b) artificially remineralized enamel, c) natural caries lesion, d) healthy enamel.The scale bar and colour intensity bar are representative for all images.
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pone-0108879-g005: Scanning microradiography area scans showing the relative mineral density distribution of a) artificially demineralized lesion, b) artificially remineralized enamel, c) natural caries lesion, d) healthy enamel.The scale bar and colour intensity bar are representative for all images.

Mentions: Fig. 5 shows the SMR area maps of the percentage change in mineral concentration for each slice. The maximum value for each enamel slice was defined as 100% mineral concentration in the unaffected region away from the lesion. The artificially demineralized enamel regions (Fig. 5a) can be differentiated from the healthy regions. For example Fig. 5c, shows a 10–30% lower mineral mass in the body of the lesion. Fig. 5b shows the artificially remineralized enamel and the uniformity of the mineral concentration across the tooth is such that the treated area is indistinguishable from the unaffected areas. The naturally carious (Fig. 5c) enamel shows a thin, low mineralized barrier isolating the subsurface lesion with an average 30% mineral mass reduction. Mineral density of the surrounding enamel is higher and uniformly distributed. The control, healthy enamel (Fig. 5d) shows uniform high mineral concentration. It should be noted that the thickness of the slices (500 µm) results in partial volume edge effects at the periphery, but this does not interfere with the measurement of the bulk enamel.


Recovery of crystallographic texture in remineralized dental enamel.

Siddiqui S, Anderson P, Al-Jawad M - PLoS ONE (2014)

Scanning microradiography area scans showing the relative mineral density distribution of a) artificially demineralized lesion, b) artificially remineralized enamel, c) natural caries lesion, d) healthy enamel.The scale bar and colour intensity bar are representative for all images.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4215832&req=5

pone-0108879-g005: Scanning microradiography area scans showing the relative mineral density distribution of a) artificially demineralized lesion, b) artificially remineralized enamel, c) natural caries lesion, d) healthy enamel.The scale bar and colour intensity bar are representative for all images.
Mentions: Fig. 5 shows the SMR area maps of the percentage change in mineral concentration for each slice. The maximum value for each enamel slice was defined as 100% mineral concentration in the unaffected region away from the lesion. The artificially demineralized enamel regions (Fig. 5a) can be differentiated from the healthy regions. For example Fig. 5c, shows a 10–30% lower mineral mass in the body of the lesion. Fig. 5b shows the artificially remineralized enamel and the uniformity of the mineral concentration across the tooth is such that the treated area is indistinguishable from the unaffected areas. The naturally carious (Fig. 5c) enamel shows a thin, low mineralized barrier isolating the subsurface lesion with an average 30% mineral mass reduction. Mineral density of the surrounding enamel is higher and uniformly distributed. The control, healthy enamel (Fig. 5d) shows uniform high mineral concentration. It should be noted that the thickness of the slices (500 µm) results in partial volume edge effects at the periphery, but this does not interfere with the measurement of the bulk enamel.

Bottom Line: Little is known about the crystallographic effects of demineralization and remineralization.Remineralization restores the texture to the original level seen in healthy enamel and restores mineral density.The results also showed that remineralization promotes ordered formation of new crystallites and growth of pre-existing crystallites which match the preferred orientation of healthy enamel.

View Article: PubMed Central - PubMed

Affiliation: Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom.

ABSTRACT
Dental caries is the most prevalent disease encountered by people of all ages around the world. Chemical changes occurring in the oral environment during the caries process alter the crystallography and microstructure of dental enamel resulting in loss of mechanical function. Little is known about the crystallographic effects of demineralization and remineralization. The motivation for this study was to develop understanding of the caries process at the crystallographic level in order to contribute towards a long term solution. In this study synchrotron X-ray diffraction combined with scanning electron microscopy and scanning microradiography have been used to correlate enamel crystallography, microstructure and mineral concentration respectively in enamel affected by natural caries and following artificial demineralization and remineralization regimes. In particular, the extent of destruction and re-formation of this complex structure has been measured. 2D diffraction patterns collected at the European Synchrotron Radiation Facility were used to quantify changes in the preferred orientation (crystallographic texture) and position of the (002) Bragg reflection within selected regions of interest in each tooth slice, and then correlated with the microstructure and local mineral mass. The results revealed that caries and artificial demineralization cause a large reduction in crystallographic texture which is coupled with the loss of mineral mass. Remineralization restores the texture to the original level seen in healthy enamel and restores mineral density. The results also showed that remineralization promotes ordered formation of new crystallites and growth of pre-existing crystallites which match the preferred orientation of healthy enamel. Combining microstructural and crystallographic characterization aids the understanding of caries and erosion processes and assists in the progress towards developing therapeutic treatments to allow affected enamel to regain structural integrity.

Show MeSH
Related in: MedlinePlus