Limits...
The dentin organic matrix - limitations of restorative dentistry hidden on the nanometer scale.

Bertassoni LE, Orgel JP, Antipova O, Swain MV - Acta Biomater (2012)

Bottom Line: Research has shown, however, that this interaction imposes less than desirable long-term prospects for current resin-based dental restorations.Finally, we discuss the relation of these complexly assembled nanostructures with the protease degradative processes driving the low durability of current resin-based dental restorations.We argue in favour of the structural limitations that these complexly organized and inherently hydrated organic structures may impose on the clinical prospects of current hydrophobic and hydrolyzable dental polymers that establish ultrafine contact with the tooth substrate.

View Article: PubMed Central - PubMed

Affiliation: Biomaterials Science Research Unit, Faculty of Dentistry, University of Sydney, United Dental Hospital, NSW, Australia. luiz.bertassoni@sydney.edu.au

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Collagen fibril disaggregation unravelling thinner collagen internal substructural units. (A) SEM image of corneal collagen fibrils treated with acetic acid and dissociated into thinner (∼10 nm) fibrillar entities (no scale bar reported, ×79,000) (adapted from Yamamoto et al. [64]). (B) Demineralized dentin collagen fibrils treated with trypsin yielding an untwistedrope like appearance and unravelling ∼20 nm substructural fibrillar disaggregates (200 nm scale bar, ×160,000).
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f0015: Collagen fibril disaggregation unravelling thinner collagen internal substructural units. (A) SEM image of corneal collagen fibrils treated with acetic acid and dissociated into thinner (∼10 nm) fibrillar entities (no scale bar reported, ×79,000) (adapted from Yamamoto et al. [64]). (B) Demineralized dentin collagen fibrils treated with trypsin yielding an untwistedrope like appearance and unravelling ∼20 nm substructural fibrillar disaggregates (200 nm scale bar, ×160,000).

Mentions: More specifically to dentin, we have recently obtained evidence of demineralized collagen following treatment with trypsin, which clearly unravelled consistent 20 nm thin fibrillar units originating from larger D-periodical fibrils (Fig. 3). The resemblance between the “untwisted rope” appearance reported by Yamamoto et al. [64], as well as the structures described by Scott [63] and Raspanti et al. [65] with the thinner fibrillar disaggregates we found is striking (Fig. 3). Scott hypothesized that the disaggregation of larger fibrils into thinner fibrillar entities demonstrates that there are characteristic aggregates of collagen molecules which are more stable than thicker “parent” fibrils [63]. Accordingly, collagen microfibrils (∼5 nm diameter) may assemble into concentric bundles, thus forming substructural units 10–25 nm in diameter, perhaps in a transient state, and the interactions within the assembled bundles would be stronger than those between them, since the microfibrillar bundles themselves did not disaggregate under conditions sufficient to cause unravelling of the larger D-periodical fibrils [63].


The dentin organic matrix - limitations of restorative dentistry hidden on the nanometer scale.

Bertassoni LE, Orgel JP, Antipova O, Swain MV - Acta Biomater (2012)

Collagen fibril disaggregation unravelling thinner collagen internal substructural units. (A) SEM image of corneal collagen fibrils treated with acetic acid and dissociated into thinner (∼10 nm) fibrillar entities (no scale bar reported, ×79,000) (adapted from Yamamoto et al. [64]). (B) Demineralized dentin collagen fibrils treated with trypsin yielding an untwistedrope like appearance and unravelling ∼20 nm substructural fibrillar disaggregates (200 nm scale bar, ×160,000).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3473357&req=5

f0015: Collagen fibril disaggregation unravelling thinner collagen internal substructural units. (A) SEM image of corneal collagen fibrils treated with acetic acid and dissociated into thinner (∼10 nm) fibrillar entities (no scale bar reported, ×79,000) (adapted from Yamamoto et al. [64]). (B) Demineralized dentin collagen fibrils treated with trypsin yielding an untwistedrope like appearance and unravelling ∼20 nm substructural fibrillar disaggregates (200 nm scale bar, ×160,000).
Mentions: More specifically to dentin, we have recently obtained evidence of demineralized collagen following treatment with trypsin, which clearly unravelled consistent 20 nm thin fibrillar units originating from larger D-periodical fibrils (Fig. 3). The resemblance between the “untwisted rope” appearance reported by Yamamoto et al. [64], as well as the structures described by Scott [63] and Raspanti et al. [65] with the thinner fibrillar disaggregates we found is striking (Fig. 3). Scott hypothesized that the disaggregation of larger fibrils into thinner fibrillar entities demonstrates that there are characteristic aggregates of collagen molecules which are more stable than thicker “parent” fibrils [63]. Accordingly, collagen microfibrils (∼5 nm diameter) may assemble into concentric bundles, thus forming substructural units 10–25 nm in diameter, perhaps in a transient state, and the interactions within the assembled bundles would be stronger than those between them, since the microfibrillar bundles themselves did not disaggregate under conditions sufficient to cause unravelling of the larger D-periodical fibrils [63].

Bottom Line: Research has shown, however, that this interaction imposes less than desirable long-term prospects for current resin-based dental restorations.Finally, we discuss the relation of these complexly assembled nanostructures with the protease degradative processes driving the low durability of current resin-based dental restorations.We argue in favour of the structural limitations that these complexly organized and inherently hydrated organic structures may impose on the clinical prospects of current hydrophobic and hydrolyzable dental polymers that establish ultrafine contact with the tooth substrate.

View Article: PubMed Central - PubMed

Affiliation: Biomaterials Science Research Unit, Faculty of Dentistry, University of Sydney, United Dental Hospital, NSW, Australia. luiz.bertassoni@sydney.edu.au

Show MeSH
Related in: MedlinePlus