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Dexamethasone and zinc loaded polymeric nanoparticles reinforce and remineralize coronal dentin. A morpho-histological and dynamic-biomechanical study. Dent Mater 2023; 39:41-56. [PMID: 36460577 DOI: 10.1016/j.dental.2022.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 11/18/2022] [Accepted: 11/25/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To investigate the effect of novel polymeric nanoparticles (NPs) doped with dexamethasone (Dex) on viscoelasticity, crystallinity and ultra-nanostructure of the formed hydroxyapatite after NPs dentin infiltration. METHODS Undoped-NPs, Dex-doped NPs (Dex-NPs) and zinc-doped-Dex-NPs (Zn-Dex-NPs) were tested at dentin, after 24 h and 21 d. A control group without NPs was included. Coronal dentin surfaces were studied by nano-dynamic mechanical analysis measurements, atomic force microscopy, X-ray diffraction and transmission electron microscopy. Mean and standard deviation were analyzed by ANOVA and Student-Newman-Keuls multiple comparisons (p < 0.05). RESULTS At 21 d of storage time, both groups doped with Dex exhibited the highest complex, storage and loss moduli among groups. Zn-Dex-NPs and Dex-NPs promoted the highest and lowest tan delta values, respectively. Dex-NPs contributed to increase the fibril diameters of dentin collagen over time. Dentin surfaces treated with Zn-Dex-NPs attained the lowest nano-roughness values, provoked the highest crystallinity, and produced the longest and shortest crystallite and grain size. These new crystals organized with randomly oriented lattices. Dex-NPs induced the highest microstrain. Crystalline and amorphous matter was present in the mineral precipitates of all groups, but Zn and Dex loaded NPs helped to increase crystallinity. SIGNIFICANCE Dentin treated with Zn-Dex-NPs improved crystallographic and atomic order, providing structural stability, high mechanical performance and tissue maturation. Amorphous content was also present, so high hydroxyapatite solubility, bioactivity and remineralizing activity due to the high ion-rich environment took place in the infiltrated dentin.
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Diez-García S, Sánchez-Martín MJ, Amigo JM, Valiente M. Combination of Two Synchrotron Radiation-Based Techniques and Chemometrics to Study an Enhanced Natural Remineralization of Enamel. Anal Chem 2022; 94:5359-5366. [PMID: 35319204 PMCID: PMC8988122 DOI: 10.1021/acs.analchem.1c05498] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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The limitations to
assess dental enamel remineralization have been
overcome by a methodology resulting from the appropriate combination
of synchrotron radiation-based techniques on both, infrared microspectroscopy
and micro X-ray diffraction, with the help of specific data mining.
Since amelogenin plays a key role in modulating the mineralization
of tooth enamel, we propose a controlled ion release for fluorapatite
structural ions (Ca2+, PO43–, and F–, also including Zn2+) by using
weak acid and weak base ion-exchange resins in the presence of amelogenin
to remineralize the surface of etched teeth. This combination provides
the necessary ions for enamel remineralization and a guide for crystal
growth due to the protein. Remineralized tooth samples were analyzed
by applying the indicated methodology. The synchrotron data were treated
using principal component analysis and multivariate curve resolution
to analyze the mineral layer formed in the presence and absence of
amelogenin. The remineralizing treatment created a fluorapatite layer
free of carbonate impurities and with a similar orientation to that
of the natural enamel thanks to amelogenin contribution.
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Affiliation(s)
- Sandra Diez-García
- GTS Research Group, Department of Chemistry, Faculty of Science, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - María-Jesús Sánchez-Martín
- GTS Research Group, Department of Chemistry, Faculty of Science, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - José Manuel Amigo
- Ikerbasque, Basque Foundation for Science, María Díaz de Haro, 48013 Bilbao, Spain.,Department of Analytical Chemistry, University of the Basque Country UPV/EHU, P.O. Box 644, 15 48080 Bilbao, Basque Country, Spain
| | - Manuel Valiente
- GTS Research Group, Department of Chemistry, Faculty of Science, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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Zalite V, Lungevics J, Vecstaudza J, Stipniece L, Locs J. Nanosized calcium deficient hydroxyapatites for tooth enamel protection. J Biomed Mater Res B Appl Biomater 2021; 110:1354-1367. [PMID: 34965008 PMCID: PMC9306847 DOI: 10.1002/jbm.b.35005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 11/23/2022]
Abstract
Calcium phosphates (CaP) are extensively studied as additives to dental care products for tooth enamel protection against caries. However, it is not clear yet whether substituted CaP could provide better enamel protection. In this study we produced, characterized and tested in vitro substituted and co‐substituted calcium deficient hydroxyapatite (CDHAp) with Sr2+ and F− ions. X‐ray powder diffractometry, Fourier transformation infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray analysis, Brunauer–Emmett–Teller were used to characterize synthesized powders and also cytotoxicity was evaluated. pH = f(t) test was performed to estimate, weather synthesized CDHAp suspensions are able to increase pH of experimental media after acid addition. Synthesis products were incorporated into paste to perform in vitro remineralization on the bovine enamel. In addition to mentioned instrumental methods, profilometry was used for evaluation of remineralised enamel samples. The obtained results confirmed formation of CDHAp substituted with 1.5–1.6 wt% of fluoride and 7.4–7.8 wt% of strontium. pH = f(t) experiment pointed out that pH increased by approximately 0.3 within 10 min after acid addition for all CDHAp suspensions. A new layer of the corresponding CDHAp was formed on the enamel. Its thickness increased by 0.8 ± 0.1 μm per day and reached up to 5.8 μm after 7 days. Additionally, octa calcium phosphates were detected on the surface of control samples. In conclusion, we can assume that CDHAp substituted with Sr2+ and/or F− could be used as an effective additive to dental care products promoting formation of protecting layer on the enamel, but there was no significant difference among sample groups.
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Affiliation(s)
- Vita Zalite
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Janis Lungevics
- Department of Mechanical Engineering and Mechatronics, Faculty of Mechanical Engineering, Transport and Aeronautics, Riga Technical University, Riga, Latvia
| | - Jana Vecstaudza
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Liga Stipniece
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Janis Locs
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia.,Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
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Toledano-Osorio M, Aguilera FS, Muñoz-Soto E, Osorio E, Toledano M, Escames G, Medina-Castillo AL, Osorio MT, López-López MT, Vallecillo-Rivas M, Osorio R. Melatonin-doped polymeric nanoparticles induce high crystalline apatite formation in root dentin. Dent Mater 2021; 37:1698-1713. [PMID: 34544591 DOI: 10.1016/j.dental.2021.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/04/2021] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the effect of novel polymeric nanoparticles (NPs) doped with melatonin (ML) on nano-hardness, crystallinity and ultrastructure of the formed hydroxyapatite after endodontic treatment. METHODS Undoped-NPs and ML-doped NPs (ML-NPs) were tested at radicular dentin, after 24 h and 6 m. A control group without NPs was included. Radicular cervical and apical dentin surfaces were studied by nano-hardness measurements, X-ray diffraction and transmission electron microscopy. Mean and standard deviation were analyzed by ANOVA and Student-Newman-Keuls multiple comparisons (p < 0.05). RESULTS Cervical dentin treated with undoped NPs maintained its nano-hardness values after 6 m of storage being [24 h: 0.29 (0.01); 6 m: 0.30 (0.02) GPa], but it decreased at apical dentin [24 h: 0.36 (0.01); 6 m: 0.28 (0.02) GPa]. When ML-NPs were used, nano-hardness was similar over time [24h: 0.31 (0.02); 6 m: 0.28 (0.03) GPa], at apical dentin. Root dentin treated with ML-NPs produced, in general, high crystallinity of new minerals and thicker crystals than those produced in the rest of the groups. After 6 m, crystals became organized in randomly oriented polyhedral, square polygonal block-like apatite or drop-like apatite polycrystalline lattices when ML-NPs were used. Undoped NPs generated poor crystallinity, with preferred orientation of small crystallite and increased microstrain. SIGNIFICANCE New polycrystalline formations encountered in dentin treated with ML-NPs may produce structural dentin stability and high mechanical performance at the root. The decrease of mechanical properties over time in dentin treated without NPs indicates scarce remineralization potential, dentin demineralization and further potential degradation. The amorphous stage may provide high hydroxyapatite solubility and remineralizing activity.
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Affiliation(s)
- Manuel Toledano-Osorio
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Fátima S Aguilera
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Esther Muñoz-Soto
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Estrella Osorio
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Manuel Toledano
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain.
| | - Germaine Escames
- Faculty of Medicine, Department of Physiology, Biomedical Research Center, CIBERFES, Ibs. San Cecilio University Hospital, University of Granada, Granada, Spain
| | - Antonio L Medina-Castillo
- University of Granada, NanoMyP, Spin-Off Enterprise, Edificio BIC-Granada, Av. Innovación 1, 18016, Armilla, Granada, Spain
| | | | - Modesto T López-López
- University of Granada, Faculty of Science, Applied Physics Department, Av. Fuente Nueva s/n, 18071 Granada, Spain
| | - Marta Vallecillo-Rivas
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Raquel Osorio
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
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Melatonin-doped polymeric nanoparticles reinforce and remineralize radicular dentin: Morpho-histological, chemical and biomechanical studies. Dent Mater 2021; 37:1107-1120. [PMID: 33846017 DOI: 10.1016/j.dental.2021.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/15/2021] [Accepted: 03/28/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVES To investigate the effectiveness of novel polymeric nanoparticles (NPs) doped with melatonin (ML) in reducing dentin permeability and facilitating dentin remineralization after endodontic treatment. METHODS The effect of undoped NPs and ML-doped NPs (ML-NPs) was tested in radicular dentin, at 24 h and 6 m. A control group without NPs was included. ML liberation was measured. Radicular dentin was assessed for fluid filtration. Dentin remineralization was analyzed by scanning electron microscopy, AFM, Young's modulus (Ei), Nano DMA-tan delta, and Raman analysis. RESULTS ML release ranged from 1.85 mg/mL at 24 h to 0.033 mg/mL at 28 d. Both undoped NPs and ML-NPs treated dentin exhibited the lowest microleakage, but samples treated with ML-NPs exhibited hermetically sealed dentinal tubules and extended mineral deposits onto dentin. ML-NPs promoted higher and durable Ei, and functional remineralization at root dentin, generating differences between the values of tan delta among groups and creating zones of stress concentration. Undoped-NPs produced closure of some tubules and porosities at the expense of a relative mineral amorphization. Chemical remineralization based on mineral and organic assessments was higher in samples treated with ML-NPs. When using undoped NPs, precipitation of minerals occurred; however, radicular dentin was not mechanically reinforced but weakened over time. SIGNIFICANCE Application of ML-NPs in endodontically treated teeth, previous to the canal filling step, is encouraged due to occlusion of dentinal tubules and the reinforcement of the radicular dentin structure.
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The Effect of Dietary Rye Inclusion and Xylanase Supplementation on Structural Organization of Bone Constitutive Phases in Laying Hens Fed a Wheat-Corn Diet. Animals (Basel) 2020; 10:ani10112010. [PMID: 33142930 PMCID: PMC7692776 DOI: 10.3390/ani10112010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 10/25/2020] [Accepted: 10/29/2020] [Indexed: 12/31/2022] Open
Abstract
This study was conducted to examine the effect of dietary rye inclusion and xylanase supplementation on the bone quality of ISA Brown laying hens. Ninety-six laying hens were assigned to four groups: fed with wheat-corn diet or rye-wheat-corn diet (25% of hybrid rye inclusion) or nonsupplemented or supplemented with xylanase (200 mg/kg of feed) for a period of 25 weeks, from the 26th to the 50th week of age. X-ray absorptiometry, X-ray diffraction, and Fourier-transform infrared spectroscopy were used to provide comprehensive information about the structural organization of bone constitutive phases of the tibia mid-diaphysis in hens from all treatment groups. Bone hydroxyapatite size was not affected by diet. Xylanase supplementation influenced the carbonate-to-phosphate ratio and crystallinity index in hens fed with both diets. Xylanase had more pronounced effects on bone mineral density and collagen maturity in hens fed with the rye-wheat-corn diet versus those fed with the wheat-corn diet. The results of this study showed that modern rye varieties, when supplemented with exogenous xylanase, can be introduced to the diet of laying hens without any adverse effects on bone structure.
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Hydroxyapatite-based cements induce different apatite formation in radicular dentin. Dent Mater 2020; 36:167-178. [DOI: 10.1016/j.dental.2019.11.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 11/04/2019] [Accepted: 11/15/2019] [Indexed: 01/22/2023]
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Characteristics of (002) Oriented Hydroxyapatite Coatings Deposited by Atmospheric Plasma Spraying. COATINGS 2018. [DOI: 10.3390/coatings8080258] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hydroxyapatite (HA) coatings with strong (002) preferred orientation were successfully prepared on Ti-6Al-4V substrates with conventional atmospheric plasma spraying (APS). The intensity changes of (002) preferred orientation along the coating depth were investigated and the mechanical properties of these coatings were analyzed. Results indicated that the intensity of (002) preferred orientation at a distance of longer than ~90 mm from the interface showed a high value, where uniformly distributed columnar grains in a direction perpendicular to the coating surface were observed. The results obtained from experiments on the mechanical properties revealed that the (002) oriented coatings prepared by conventional APS technique exhibited excellent mechanical properties. Meanwhile, this study provided a simple and rapid method for the preparation of HA coatings with (002) preferred orientation.
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Dessombz A, Lignon G, Picaut L, Rouzière S, Berdal A. Mineral studies in enamel, an exemplary model system at the interface between physics, chemistry and medical sciences. CR CHIM 2016. [DOI: 10.1016/j.crci.2015.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Toledano M, Aguilera FS, López-López MT, Osorio E, Toledano-Osorio M, Osorio R. Zinc-Containing Restorations Create Amorphous Biogenic Apatite at the Carious Dentin Interface: A X-Ray Diffraction (XRD) Crystal Lattice Analysis. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2016; 22:1034-1046. [PMID: 27681364 DOI: 10.1017/s1431927616011697] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The aim of this research was to assess the ability of amalgam restorations to induce amorphous mineral precipitation at the caries-affected dentin substrate. Sound and caries-affected dentin surfaces were subjected to both Zn-free and Zn-containing dental amalgam restorations. Specimens were submitted to thermocycling (100,000 cycles/5°C-55°C, 3 months). Dentin surfaces were studied by atomic force microscopy (nanoroughness), X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive analysis, for physical and morphological surface characterization. Zn-containing amalgam placement reduced crystallinity, crystallite size, and grain size of calcium phosphate crystallites at the dentin surface. Both microstrain and nanoroughness were augmented in caries-affected dentin restored with Zn-containing amalgams. Caries-affected dentin showed the shortest mineral crystallites (11.04 nm), when Zn-containing amalgams were used for restorations, probably leading to a decrease of mechanical properties which might favor crack propagation and deformation. Sound dentin restored with Zn-free amalgams exhibited a substantial increase in length of grain particles (12.44 nm) embedded into dentin crystallites. Zn-containing amalgam placement creates dentin mineralization and the resultant mineral was amorphous in nature. Amorphous calcium phosphate provides a local ion-rich environment, which is considered favorable for in situ generation of prenucleation clusters, promotong further dentin remineralization.
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Affiliation(s)
- Manuel Toledano
- 1Dental Materials Section, Faculty of Dentistry,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain
| | - Fátima S Aguilera
- 1Dental Materials Section, Faculty of Dentistry,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain
| | - Modesto T López-López
- 2Applied Physics Department, Faculty of Science,University of Granada,Fuente Nueva s/n,18071 Granada,Spain
| | - Estrella Osorio
- 1Dental Materials Section, Faculty of Dentistry,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain
| | - Manuel Toledano-Osorio
- 1Dental Materials Section, Faculty of Dentistry,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain
| | - Raquel Osorio
- 1Dental Materials Section, Faculty of Dentistry,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain
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Chen W, Tian B, Lei Y, Ke QF, Zhu ZA, Guo YP. Hydroxyapatite coatings with oriented nanoplate and nanorod arrays: Fabrication, morphology, cytocompatibility and osteogenic differentiation. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 67:395-408. [DOI: 10.1016/j.msec.2016.04.106] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Revised: 03/28/2016] [Accepted: 04/27/2016] [Indexed: 11/30/2022]
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Sui T, Lunt AJG, Baimpas N, Sandholzer MA, Hu J, Dolbnya IP, Landini G, Korsunsky AM. Hierarchical modelling of in situ elastic deformation of human enamel based on photoelastic and diffraction analysis of stresses and strains. Acta Biomater 2014; 10:343-54. [PMID: 24121194 DOI: 10.1016/j.actbio.2013.09.043] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 09/25/2013] [Accepted: 09/30/2013] [Indexed: 11/15/2022]
Abstract
Human enamel is a typical hierarchical mineralized tissue with a two-level composite structure. To date, few studies have focused on how the mechanical behaviour of this tissue is affected by both the rod orientation at the microscale and the preferred orientation of mineral crystallites at the nanoscale. In this study, wide-angle X-ray scattering was used to determine the internal lattice strain response of human enamel samples (with differing rod directions) as a function of in situ uniaxial compressive loading. Quantitative stress distribution evaluation in the birefringent mounting epoxy was performed in parallel using photoelastic techniques. The resulting experimental data was analysed using an advanced multiscale Eshelby inclusion model that takes into account the two-level hierarchical structure of human enamel, and reflects the differing rod directions and orientation distributions of hydroxyapatite crystals. The achieved satisfactory agreement between the model and the experimental data, in terms of the values of multidirectional strain components under the action of differently orientated loads, suggests that the multiscale approach captures reasonably successfully the structure-property relationship between the hierarchical architecture of human enamel and its response to the applied forces. This novel and systematic approach can be used to improve the interpretation of the mechanical properties of enamel, as well as of the textured hierarchical biomaterials in general.
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Affiliation(s)
- Tan Sui
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK.
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Sui T, Sandholzer MA, Baimpas N, Dolbnya IP, Landini G, Korsunsky AM. Hierarchical modelling of elastic behaviour of human enamel based on synchrotron diffraction characterisation. J Struct Biol 2013; 184:136-46. [DOI: 10.1016/j.jsb.2013.09.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 09/20/2013] [Accepted: 09/26/2013] [Indexed: 11/25/2022]
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Egan CK, Jacques SDM, Di Michiel M, Cai B, Zandbergen MW, Lee PD, Beale AM, Cernik RJ. Non-invasive imaging of the crystalline structure within a human tooth. Acta Biomater 2013; 9:8337-45. [PMID: 23791674 DOI: 10.1016/j.actbio.2013.06.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/17/2013] [Accepted: 06/11/2013] [Indexed: 11/29/2022]
Abstract
The internal crystalline structure of a human molar tooth has been non-destructively imaged in cross-section using X-ray diffraction computed tomography. Diffraction signals from high-energy X-rays which have large attenuation lengths for hard biomaterials have been collected in a transmission geometry. Coupling this with a computed tomography data acquisition and mathematically reconstructing their spatial origins, diffraction patterns from every voxel within the tooth can be obtained. Using this method we have observed the spatial variations of some key material parameters including nanocrystallite size, organic content, lattice parameters, crystallographic preferred orientation and degree of orientation. We have also made a link between the spatial variations of the unit cell lattice parameters and the chemical make-up of the tooth. In addition, we have determined how the onset of tooth decay occurs through clear amorphization of the hydroxyapatite crystal, and we have been able to map the extent of decay within the tooth. The described method has strong prospects for non-destructive probing of mineralized biomaterials.
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Affiliation(s)
- Christopher K Egan
- School of Materials, The University of Manchester, Manchester M13 9PL, UK.
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