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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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SEM images of enamel from the surface of a) artificially demineralized b) artificially remineralized c) naturally carious (surface) and d) healthy region.The inset to d) shows the bulk of the carious region ∼150 µm from the surface.
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pone-0108879-g006: SEM images of enamel from the surface of a) artificially demineralized b) artificially remineralized c) naturally carious (surface) and d) healthy region.The inset to d) shows the bulk of the carious region ∼150 µm from the surface.

Mentions: Fig. 6 shows representative SEM images close to the natural surface of the named regions in each specimen. The prisms in artificially demineralized enamel (Fig. 6a) appear etched where prism cores have been significantly more affected than the walls of the prisms and the interprismatic enamel which remain more intact. The image for the remineralized enamel (Fig. 6b) shows thin plate-like deposits arranged in clusters (lacking directional growth), forming a layer over the entire surface of the enamel specimen, with some small crystallites visible underneath. The crystallite morphology of the outer surface of the naturally carious enamel (Fig. 6c) resembles healthy enamel (long, thin, ordered crystals). However, moving in towards the bulk of the enamel towards the body of the lesion (inset), there is a loss of microstructural organisation and crystallites have fused together giving an amorphous appearance, with no distinct boundaries. Healthy enamel (Fig. 6d) shows long thin, needle like, bundles of crystals with preferred orientation evident.


Recovery of crystallographic texture in remineralized dental enamel.

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

SEM images of enamel from the surface of a) artificially demineralized b) artificially remineralized c) naturally carious (surface) and d) healthy region.The inset to d) shows the bulk of the carious region ∼150 µm from the surface.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0108879-g006: SEM images of enamel from the surface of a) artificially demineralized b) artificially remineralized c) naturally carious (surface) and d) healthy region.The inset to d) shows the bulk of the carious region ∼150 µm from the surface.
Mentions: Fig. 6 shows representative SEM images close to the natural surface of the named regions in each specimen. The prisms in artificially demineralized enamel (Fig. 6a) appear etched where prism cores have been significantly more affected than the walls of the prisms and the interprismatic enamel which remain more intact. The image for the remineralized enamel (Fig. 6b) shows thin plate-like deposits arranged in clusters (lacking directional growth), forming a layer over the entire surface of the enamel specimen, with some small crystallites visible underneath. The crystallite morphology of the outer surface of the naturally carious enamel (Fig. 6c) resembles healthy enamel (long, thin, ordered crystals). However, moving in towards the bulk of the enamel towards the body of the lesion (inset), there is a loss of microstructural organisation and crystallites have fused together giving an amorphous appearance, with no distinct boundaries. Healthy enamel (Fig. 6d) shows long thin, needle like, bundles of crystals with preferred orientation evident.

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