Artificial enamel induced by phase transformation of amorphous nanoparticles

Onuma, Kazuo; Iijima, Mayumi

doi:10.1038/s41598-017-02949-w

Cited by 37 publications

(25 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…19 In our previous study, in which an ACP substrate was immersed in calcifying solution containing 10 ppm fluoride, the average fluoride content of the overgrown layer was 2.87 ± 0.28 atomic %. 16 In the presence of 1 ppm fluoride, it is possible that less fluoride (one order less) is incorporated into the HAp lattice, forming partially fluoridated HAp. Here, however, HAp was used otherwise specially mentioned.…”

Section: Resultsmentioning

confidence: 99%

“…A "root of tree" structure was observed at 5 min (white arrows), and then this structure changed into flakes over time. 16 With 0.7 and 1.0 ppm fluoride, nanoparticles precipitated after 1 min; the amount increased for 3−5 min, and flakes with uneven edges formed after 10 min. Without fluoride, flakes with even edges formed after 30 min, while with 0.7 and 1.0 ppm fluoride, irregularly-shaped small flakes formed after 30 min.…”

Section: Crystal Growth and Designmentioning

confidence: 94%

“…15 We recently found that highly oriented and tightly assembled HAp nanorods grow on an amorphous calcium phosphate (ACP) substrate if the substrate is immersed in a metastable calcium phosphate solution containing 10 ppm fluoride, while plate-like micrometer-size OCP crystals grow with c-axial orientation in the absence of fluoride. 16 Cross-sectional characterization of the overgrown layer revealed that, with 10 ppm fluoride, a thin intermediate layer (IL) composed of low-crystalline HAp nanoparticles formed and that HAp nanorods grew on the IL. In contrast, without fluoride, an IL did not form.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Roles of Fluoride on Octacalcium Phosphate and Apatite Formation on Amorphous Calcium Phosphate Substrate

Iijima

Onuma

2018

Crystal Growth & Design

Self Cite

View full text Add to dashboard Cite

As fluoride is known to affect the biomineralization of calcium phosphates, we examined how the growth at 37 °C of octacalcium phosphate (OCP) and hydroxyapatite (HAp) on an amorphous calcium phosphate substrate is affected by low-dose fluoride (0–2 ppm) in metastable calcium phosphate solution. In the absence of fluoride, highly oriented plate-like OCP crystals grow on the substrate. With 0.7–0.8 ppm fluoride, OCP crystal formation was greatly modulated (the crystals were smaller and their orientation was lower); moreover, tiny plates and needles appeared on the OCP plates. There were two critical fluoride concentrations: (1) at 0.9 ppm, the OCP plates were completely replaced by HAp nanorods; (2) at 1 ppm, the structure of the HAp nanorod assembly changed from an open one to a tightly assembled one. The fluoride suppressed OCP formation, induced HAp nanorod formation, and promoted tight nanorod assembly. The relationship between the fluoride concentration and the formation of OCP and HAp provides insight into the structural design of an OCP/HAp coating layer and should be useful in the application of fluoride to an OCP/HAp coating on any substrate.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Crystal Growth and Designmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Roles of Fluoride on Octacalcium Phosphate and Apatite Formation on Amorphous Calcium Phosphate Substrate

Iijima

Onuma

2018

Crystal Growth & Design

Self Cite

View full text Add to dashboard Cite

show abstract

“…Contrary to what is currently understood, reactive amorphous nanoparticles and their transformation efficiently induce a matrix structure. [ 19 ]…”

Section: Discussionmentioning

confidence: 99%

Assessment of structural changes in translucency and opacity of tooth enamel against a direct demineralization process: An in vitro study

Ruiz

Soriano

Gallo

et al. 2020

J Int Soc Prevent Communit Dent

View full text Add to dashboard Cite

A BSTRACT Objective: The objective of this study was to assess in vitro the structural changes in translucency and opacity of tooth enamel following a direct demineralization process. Materials and Methods: This experimental in vitro study evaluated 45 thirds (cervical, middle, and occlusal) of the tooth enamel surface of premolar teeth extracted from young adults divided into three groups of 15 specimens each: Group 1 (solution based on calcium, phosphorus, and fluorine), Group 2 (orthophosphoric acid 37%), and control group (distilled water). All underwent optical macroscopic examination with ×3 magnification to determine the initial translucency according to the variation of the medium in their intercrystalline spaces, and Thylstrup and Fejerskov Index was used. The experimental groups were then subjected to an artificial caries process during which the specimens were placed in an inorganic and organic solution of calcium, phosphorus, and fluorine at 37°C for 90 days with the acidic solution at pH 5 and the neutral solution at pH 7. The control specimens were placed in distilled water. Finally, all the specimens were assessed by polarization microscopy. Results: In relation to the occlusal third, the highest proportion in Groups 1 and 2 was in Grades 2 and 3 (80%). A significant association was only observed between the experimental groups in the degree of translucency in the occlusal third ( P = 0.002), whereas no association was found in relation to the degree of opacity in the middle and cervical thirds in either study group ( P > 0.05). Conclusion: The resistance of enamel hydroxyapatite crystals increases from occlusal to cervical due to the greater presence of aprismatic enamel in the cervical horizontal third.

show abstract

“…In our previous study, an enamel-like HAP nanorod array was constructed on an amorphous calcium phosphate (ACP) substrate consisting of nanoparticles (<80 nm diameter) that had been compression molded [41]. When the substrate was immersed in a calcium phosphate solution without cells under pseudo-physiological conditions, ACP nanoparticles close to the substrate surface quickly transformed into HAP ones and grew perpendicularly as rods due to geometric selection.…”

Section: Discussionmentioning

confidence: 99%

Potential for Drug Repositioning of Midazolam for Dentin Regeneration

Karakida

Onuma

Saito

et al. 2019

IJMS

Self Cite

View full text Add to dashboard Cite

Drug repositioning promises the advantages of reducing costs and expediting approvalschedules. An induction of the anesthetic and sedative drug; midazolam (MDZ), regulatesinhibitory neurotransmitters in the vertebrate nervous system. In this study we show the potentialfor drug repositioning of MDZ for dentin regeneration. A porcine dental pulp-derived cell line(PPU-7) that we established was cultured in MDZ-only, the combination of MDZ with bonemorphogenetic protein 2, and the combination of MDZ with transforming growth factor-beta 1. Thedifferentiation of PPU-7 into odontoblasts was investigated at the cell biological and genetic level.Mineralized nodules formed in PPU-7 were characterized at the protein and crystal engineeringlevels. The MDZ-only treatment enhanced the alkaline phosphatase activity and mRNA levels ofodontoblast differentiation marker genes, and precipitated nodule formation containing a dentinspecificprotein (dentin phosphoprotein). The nodules consisted of randomly orientedhydroxyapatite nanorods and nanoparticles. The morphology, orientation, and chemicalcomposition of the hydroxyapatite crystals were similar to those of hydroxyapatite that hadtransformed from amorphous calcium phosphate nanoparticles, as well as the hydroxyapatite inhuman molar dentin. Our investigation showed that a combination of MDZ and PPU-7 cellspossesses high potential of drug repositioning for dentin regeneration.

show abstract

Artificial enamel induced by phase transformation of amorphous nanoparticles

Cited by 37 publications

References 39 publications

Roles of Fluoride on Octacalcium Phosphate and Apatite Formation on Amorphous Calcium Phosphate Substrate

Roles of Fluoride on Octacalcium Phosphate and Apatite Formation on Amorphous Calcium Phosphate Substrate

Assessment of structural changes in translucency and opacity of tooth enamel against a direct demineralization process: An in vitro study

Potential for Drug Repositioning of Midazolam for Dentin Regeneration

Contact Info

Product

Resources

About