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Minetti E, Palermo A, Malcangi G, Inchingolo AD, Mancini A, Dipalma G, Inchingolo F, Patano A, Inchingolo AM. Dentin, Dentin Graft, and Bone Graft: Microscopic and Spectroscopic Analysis. J Funct Biomater 2023; 14:jfb14050272. [PMID: 37233382 DOI: 10.3390/jfb14050272] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/01/2023] [Accepted: 05/12/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND The use of the human dentin matrix could serve as an alternative to autologous, allogenic, and xenogeneic bone grafts. Since 1967, when the osteoinductive characteristics of autogenous demineralized dentin matrix were revealed, autologous tooth grafts have been advocated. The tooth is very similar to the bone and contains many growth factors. The purpose of the present study is to evaluate the similarities and differences between the three samples (dentin, demineralized dentin, and alveolar cortical bone) with the aim of demonstrating that the demineralized dentin can be considered in regenerative surgery as an alternative to the autologous bone. METHODS This in vitro study analyzed the biochemical characterizations of 11 dentin granules (Group A), 11 demineralized using the Tooth Transformer (Group B), and dentin granules and 11 cortical bone granules (Group C) using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) to evaluate mineral content. Atomic percentages of C (carbon), O (oxygen), Ca (calcium), and P (phosphorus) were individually analyzed and compared by the statistical t-test. RESULTS The significant p-value (p < 0.05) between group A and group C indicated that these two groups were not significantly similar, while the non-significant result (p > 0.05) obtained between group B and group C indicated that these two groups are similar. CONCLUSIONS The findings support that the hypothesis that the demineralization process can lead to the dentin being remarkably similar to the natural bone in terms of their surface chemical composition. The demineralized dentin can therefore be considered an alternative to the autologous bone in regenerative surgery.
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Affiliation(s)
- Elio Minetti
- Department of Biomedical, Surgical, Dental Science, University of Milan, 20161 Milan, Italy
| | - Andrea Palermo
- College of Medicine and Dentistry, Birmingham B4 6BN, UK
| | - Giuseppina Malcangi
- Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", 70124 Bari, Italy
| | | | - Antonio Mancini
- Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", 70124 Bari, Italy
| | - Gianna Dipalma
- Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", 70124 Bari, Italy
| | - Francesco Inchingolo
- Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", 70124 Bari, Italy
| | - Assunta Patano
- Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", 70124 Bari, Italy
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Surface and Structural Studies of Age-Related Changes in Dental Enamel: An Animal Model. MATERIALS 2022; 15:ma15113993. [PMID: 35683290 PMCID: PMC9182525 DOI: 10.3390/ma15113993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/26/2022] [Accepted: 06/01/2022] [Indexed: 01/28/2023]
Abstract
In the animal kingdom, continuously erupting incisors provided an attractive model for studying the enamel matrix and mineral composition of teeth during development. Enamel, the hardest mineral tissue in the vertebrates, is a tissue sensitive to external conditions, reflecting various disturbances in its structure. The developing dental enamel was monitored in a series of incisor samples extending the first four weeks of postnatal life in the spiny mouse. The age-dependent changes in enamel surface morphology in the micrometre and nanometre-scale and a qualitative assessment of its mechanical features were examined by applying scanning electron microscopy (SEM) and atomic force microscopy (AFM). At the same time, structural studies using XRD and vibrational spectroscopy made it possible to assess crystallinity and carbonate content in enamel mineral composition. Finally, a model for predicting the maturation based on chemical composition and structural factors was constructed using artificial neural networks (ANNs). The research presented here can extend the existing knowledge by proposing a pattern of enamel development that could be used as a comparative material in environmental, nutritional, and pharmaceutical research.
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3
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Veiga A, Castro F, Reis CC, Sousa A, Oliveira AL, Rocha F. Hydroxyapatite/sericin composites: A simple synthesis route under near-physiological conditions of temperature and pH and preliminary study of the effect of sericin on the biomineralization process. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 108:110400. [PMID: 31923995 DOI: 10.1016/j.msec.2019.110400] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 10/23/2019] [Accepted: 11/05/2019] [Indexed: 10/25/2022]
Abstract
Synthesis of hydroxyapatite (HAp) and sericin (SS) nanocomposites was carried out by a simple precipitation method performed in batch in a stirred tank reactor (ST). The reaction was achieved by mixing a solution of calcium chloride dihydrate, in which SS was dissolved, with a solution of disodium hydrogen phosphate at 37 °C. Three experimental conditions were studied by varying the concentration of SS: HAp, HAp/SS1 (0.01 g/L of SS) and HAp/SS2 (1 g/L of SS). The chemical and physical properties of the resulting HAp/SS nanocomposites were studied using several techniques (Atomic Absorption Spectrometry, Ultraviolet-Visible Spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Selected area diffraction (SAED) and Thermogravimetric analysis (TGA)). pH profile was also monitored over time for each experimental condition. The results revealed that nano single-phased HAp was formed with both rod and plate-like shape. Additionally, the particles have low crystallinity, characteristic similar to biological HAp. Regarding the influence of SS, one observed that with increasing SS concentration there is an increase in the mean particle size and the number of plate-like particles, as well as an increase in the aggregation degree and a decrease of the crystallinity. Further, the composites obtained have an inorganic/organic composition comparable to bone. Finally, in vitro cytotoxicity showed that the synthetized nanoparticles are non-toxic and cell viability is higher for HAp and HAp/SS samples when compared to a commercially available HAp. The produced materials can thus be considered suitable candidates for bone related applications.
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Affiliation(s)
- Anabela Veiga
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology & Energy, Dep. of Chemical Engineering, Faculty of Engineering of Porto, Univ. of Porto, Porto, Portugal
| | - Filipa Castro
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology & Energy, Dep. of Chemical Engineering, Faculty of Engineering of Porto, Univ. of Porto, Porto, Portugal
| | - Cassilda Cunha Reis
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - Aureliana Sousa
- i3S - Institute for Research and Innovation in Health, Univ. of Porto, Porto, Portugal; INEB - National Institute of Biomedical Engineering, Univ. of Porto, Porto, Portugal
| | - Ana L Oliveira
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal.
| | - Fernando Rocha
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology & Energy, Dep. of Chemical Engineering, Faculty of Engineering of Porto, Univ. of Porto, Porto, Portugal
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Elkassas D, Arafa A. The innovative applications of therapeutic nanostructures in dentistry. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2017; 13:1543-1562. [PMID: 28232213 DOI: 10.1016/j.nano.2017.01.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 01/21/2017] [Accepted: 01/30/2017] [Indexed: 02/05/2023]
Abstract
Nanotechnology has paved multiple ways in preventing, reversing or restoring dental caries which is one of the major health care problems. Nanotechnology aided in processing variety of nanomaterials with innovative dental applications. Some showed antimicrobial effect helping in the preventive stage. Others have remineralizing potential intercepting early lesion progression as nanosized calcium phosphate, carbonate hydroxyapatite nanocrystals, nanoamorphous calcium phosphate and nanoparticulate bioactive glass particularly with provision of self-assembles protein that furnish essential role in biomimetic repair. The unique size of nanomaterials makes them fascinating carriers for dental products. Thus, it is recentlyclaimedthat fortifying the adhesives with nanomaterials that possess biological meritsdoes not only enhance the mechanical and physical properties of the adhesives, but also help to attain and maintain a durable adhesive joint and enhanced longevity. Accordingly, this review will focus on the current status and the future implications of nanotechnology in preventive and adhesive dentistry.
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Affiliation(s)
- Dina Elkassas
- Department of Operative Dentistry, Faculty of Oral and Dental Medicine, Misr International University, Egypt
| | - Abla Arafa
- Department of Pediatric Dentistry and Dental Public Health, Faculty of Oral and Dental Medicine, Misr International University, Egypt.
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5
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Kallistová A, Horáček I, Šlouf M, Skála R, Fridrichová M. Mammalian enamel maturation: Crystallographic changes prior to tooth eruption. PLoS One 2017; 12:e0171424. [PMID: 28196135 PMCID: PMC5308864 DOI: 10.1371/journal.pone.0171424] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 01/20/2017] [Indexed: 01/26/2023] Open
Abstract
Using the distal molar of a minipig as a model, we studied changes in the microstructural characteristics of apatite crystallites during enamel maturation (16-23 months of postnatal age), and their effects upon the mechanical properties of the enamel coat. The slow rate of tooth development in a pig model enabled us to reveal essential heterochronies in particular components of the maturation process. The maturation changes began along the enamel-dentine junction (EDJ) of the trigonid, spreading subsequently to the outer layers of the enamel coat to appear at the surface zone with a 2-month delay. Correspondingly, at the distal part of the tooth the timing of maturation processes is delayed by 3-5 month compared to the mesial part of the tooth. The early stage of enamel maturation (16-20 months), when the enamel coat is composed almost exclusively of radial prismatic enamel, is characterized by a gradual increase in crystallite thickness (by a mean monthly increment of 3.8 nm); and an increase in the prism width and thickness of crystals composed of elementary crystallites. The late stage of maturation (the last two months prior to tooth eruption), marked with the rapid appearance of the interprismatic matrix (IPM) during which the crystals densely infill spaces between prisms, is characterized by an abrupt decrease in microstrain and abrupt changes in the micromechanical properties of the enamel: a rapid increase in its ability to resist long-term load and its considerable hardening. The results suggest that in terms of crystallization dynamics the processes characterizing the early and late stage of mammalian enamel maturation represent distinct entities. In regards to common features with enamel formation in the tribosphenic molar we argue that the separation of these processes could be a common apomorphy of mammalian amelogenetic dynamics in general.
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Affiliation(s)
- Anna Kallistová
- Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, Czech Republic
- Institute of Geology of the CAS, v.v.i., Rozvojová 269, Prague 6, Czech Republic
| | - Ivan Horáček
- Department of Zoology, Faculty of Science, Charles University in Prague, Viničná 7, Czech Republic
- * E-mail:
| | - Miroslav Šlouf
- Institute of Macromolecular Chemistry of CAS v.v.i., Heyrovského náměstí 2, Prague 6, Czech Republic
| | - Roman Skála
- Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, Czech Republic
- Institute of Geology of the CAS, v.v.i., Rozvojová 269, Prague 6, Czech Republic
| | - Michaela Fridrichová
- Institute of Geology of the CAS, v.v.i., Rozvojová 269, Prague 6, Czech Republic
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6
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Buzalaf MAR, Barbosa CS, Leite ADL, Chang SR, Liu J, Czajka-Jakubowska A, Clarkson B. Enamel crystals of mice susceptible or resistant to dental fluorosis: an AFM study. J Appl Oral Sci 2014; 22:159-64. [PMID: 25025555 PMCID: PMC4072265 DOI: 10.1590/1678-775720130515] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 01/22/2014] [Indexed: 11/28/2022] Open
Abstract
Objective This study aimed to assess the overall apatite crystals profile in the enamel
matrix of mice susceptible (A/J strain) or resistant (129P3/J strain) to dental
fluorosis through analyses by atomic force microscopy (AFM). Material and Methods Samples from the enamel matrix in the early stages of secretion and maturation
were obtained from the incisors of mice from both strains. All detectable traces
of matrix protein were removed from the samples by a sequential extraction
procedure. The purified crystals (n=13 per strain) were analyzed
qualitatively in the AFM. Surface roughness profile (Ra) was measured. Results The mean (±SD) Ra of the crystals of A/J strain (0.58±0.15 nm) was lower than the
one found for the 129P3/J strain (0.66±0.21 nm) but the difference did not reach
statistical significance (t=1.187, p=0.247). Crystals of the 129P3/J strain
(70.42±6.79 nm) were found to be significantly narrower (t=4.013, p=0.0013) than
the same parameter measured for the A/J strain (90.42±15.86 nm). Conclusion Enamel crystals of the 129P3/J strain are narrower, which is indicative of slower
crystal growth and could interfere in the occurrence of dental fluorosis.
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Affiliation(s)
| | - Carolina Silveira Barbosa
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil
| | - Aline de Lima Leite
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil
| | - Sywe-Ren Chang
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, U.S.A
| | - Jun Liu
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, U.S.A
| | - Agata Czajka-Jakubowska
- Department of Conservative Dentistry and Periodontics, Poznan University of Medical Sciences, Poland
| | - Brian Clarkson
- Department of Conservative Dentistry and Periodontics, Poznan University of Medical Sciences, Poland
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Abstract
Evolution has exploited the chemical properties of Ca(2+), which facilitate its reversible binding to the sites of irregular geometry offered by biological macromolecules, to select it as a carrier of cellular signals. A number of proteins bind Ca(2+) to specific sites: those intrinsic to membranes play the most important role in the spatial and temporal regulation of the concentration and movements of Ca(2+) inside cells. Those which are soluble, or organized in non-membranous structures, also decode the Ca(2+) message to be then transmitted to the targets of its regulation. Since Ca(2+) controls the most important processes in the life of cells, it must be very carefully controlled within the cytoplasm, where most of the targets of its signaling function reside. Membrane channels (in the plasma membrane and in the organelles) mediate the entrance of Ca(2+) into the cytoplasm, ATPases, exchangers, and the mitochondrial Ca(2+) uptake system remove Ca(2+) from it. The concentration of Ca(2+) in the external spaces, which is controlled essentially by its dynamic exchanges in the bone system, is much higher than inside cells, and can, under conditions of pathology, generate a situation of dangerous internal Ca(2+) overload. When massive and persistent, the Ca(2+) overload culminates in the death of the cell. Subtle conditions of cellular Ca(2+) dyshomeostasis that affect individual systems that control Ca(2+), generate cell disease phenotypes that are particularly severe in tissues in which the signaling function of Ca(2+) has special importance, e.g., the nervous system.
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Affiliation(s)
- Marisa Brini
- Department of Biology, University of Padova, Via U. Bassi 58/B, I-35131, Padova, Italy,
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8
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Coxon TL, Brook AH, Barron MJ, Smith RN. Phenotype-genotype correlations in mouse models of amelogenesis imperfecta caused by Amelx and Enam mutations. Cells Tissues Organs 2012; 196:420-30. [PMID: 22759786 PMCID: PMC3718574 DOI: 10.1159/000336440] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2012] [Indexed: 01/19/2023] Open
Abstract
Mutations in human and in mouse orthologous genes Amelx and Enam result in a diverse range of enamel defects. In this study we aimed to investigate the phenotype-genotype correlation between the mutants and the wild-type controls in mouse models of amelogenesis imperfecta using novel measurement approaches. Ten hemi-mandibles and incisors were dissected from each group of Amelx(WT), Amelx(X/Y64H), Amelx(Y/Y64H), Amelx(Y64H/Y64H), and Enam(WT), Enam(Rgsc395) heterozygous and Enam(Rgsc395) homozygous mice. Their macro-morphology, colour and micro-topography were assessed using bespoke 2D and 3D image analysis systems and customized colour and whiteness algorithms. The novel methods identified significant differences (p ≤ 0.05) between the Amelx groups for mandible and incisor size and enamel colour and between the Enam groups for incisor size and enamel colour. The Amelx(WT) mice had the largest mandibles and incisors, followed in descending order of size by the Amelx(X/Y64H), Amelx(Y/Y64H) and Amelx(Y64H/Y64H) mice. Within the Enam groups the Enam(WT) incisors were largest and the Enam(Rgsc395) heterozygous mice were smallest. The effect on tooth morphology was also reflected by the severity of the enamel defects in the colour and whiteness assessment. Amelogenin affected mandible morphology and incisor enamel formation, while enamelin only affected incisors, supporting the multifunctional role of amelogenin. The enamelin mutation was associated with earlier forming enamel defects. The study supported the critical involvement of amelogenin and enamelin in enamel mineralization.
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Affiliation(s)
- Thomas Liam Coxon
- School of Dentistry, Faculty of Health and Life Sciences, Dental Hospital, Liverpool, UK
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9
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Zelenková M, Sohnel O, Grases F. Ultrafine Structure of the Hydroxyapatite Amorphous Phase in Noninfectious Phosphate Renal Calculi. Urology 2012; 79:968.e1-6. [DOI: 10.1016/j.urology.2011.11.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 10/13/2011] [Accepted: 11/15/2011] [Indexed: 11/29/2022]
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10
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Kwon KY, Wang E, Nofal M, Lee SW. Microscopic study of hydroxyapatite dissolution as affected by fluoride ions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:5335-5339. [PMID: 21456602 DOI: 10.1021/la200325d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Fluoride ions play a critical role in preventing tooth decay. We investigated the microscopic effects of fluoride ions on hydroxyapatite (100) surface dissolution using in situ atomic force microscopy. In the presence of 10 mM NaF, individual surface step retraction velocities decreased by about a factor of 5 as compared to NaF-free conditions. Importantly, elongated hexagonal etch pits, which are characteristic of (100) surface dissolution, were no longer observed when NaF was present. The alteration of pit shape is more distinct at a higher NaF concentration (50 mM) where triangular etch pits evolved during dissolution. Furthermore, in a fluoride concentration typical for tap water (10 μM), we observed roughening of individual step lines, resulting in the formation of scalloped morphologies. Morphological changes to individual steps across a wide range of fluoride concentrations suggest that the cariostatic capabilities of fluoride ions originate from their strong interactions with molecular steps.
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Affiliation(s)
- Ki-Young Kwon
- Department of Bioengineering, University of California, Berkeley, and Physical Biosciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
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11
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Zavala-Alonso V, Martínez-Castanon GA, Patiño-Marín N, Terrones H, Anusavice K, Loyola-Rodríguez JP. Characterization of healthy and fluorotic enamel by atomic force microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2010; 16:531-536. [PMID: 20813079 DOI: 10.1017/s1431927610093748] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The aim was to characterize the external structure, roughness, and absolute depth profile (ADP) of fluorotic enamel compared with healthy enamel. Eighty extracted human molars were classified into four groups [TFI: 0, control (C); 1-3, mild (MI); 4-5, moderate (MO); 6-9, severe fluorosis (S)] according to the Thylstrup-Fejerskov Index (TFI). All samples were analyzed by atomic force microscopy.The mean values of enamel surface roughness (ESR) in nm were: Group C, 92.6; Group MI, 188.8; Group MO, 246.9; and Group S, 532.2. The mean values of absolute depth profile in nm were: C, 1,065.7; MI, 2,360.7; MO, 2,536.7; and S, 6,146.2. The differences between mean ESR and mean ADP among groups were statistically significant (p < 0.05). This structural study confirms at the nanometer level that there is a positive association between fluorosis severity, ESR, and ADP, and there is an association with the clinical findings of fluorosis measured by TFI as well.
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Gower LB, Amos FF, Khan SR. Mineralogical signatures of stone formation mechanisms. ACTA ACUST UNITED AC 2010; 38:281-92. [PMID: 20625894 DOI: 10.1007/s00240-010-0288-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 06/24/2010] [Indexed: 10/19/2022]
Abstract
The mechanisms involved in biomineralization are modulated through interactions with organic matrix. In the case of stone formation, the role of the organic macromolecules in the complex urinary environment is not clear, but the presence of mineralogical 'signatures' suggests that some aspects of stone formation may result from a non-classical crystallization process that is induced by acidic proteins. An amorphous precursor has been detected in many biologically controlled mineralization reactions, which is thought to be regulated by non-specific interactions between soluble acidic proteins and mineral ions. Using in vitro model systems, we find that a liquid-phase amorphous mineral precursor induced by acidic polypeptides can lead to crystal textures that resemble those found in Randall's plaque and kidney stones. This polymer-induced liquid-precursor process leads to agglomerates of coalesced mineral spherules, dense-packed spherulites with concentric laminations, mineral coatings and 'cements', and collagen-associated mineralization. Through the use of in vitro model systems, the mechanisms involved in the formation of these crystallographic features may be resolved, enhancing our understanding of the potential role(s) that proteins play in stone formation.
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Affiliation(s)
- Laurie B Gower
- Department of Materials Science and Engineering, University of Florida, Gainesville, FL, USA.
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13
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Bajaj D, Arola D. Role of prism decussation on fatigue crack growth and fracture of human enamel. Acta Biomater 2009; 5:3045-56. [PMID: 19433137 DOI: 10.1016/j.actbio.2009.04.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 04/03/2009] [Accepted: 04/17/2009] [Indexed: 11/17/2022]
Abstract
The role of prism decussation on the crack growth resistance of human enamel is evaluated. Miniature inset compact tension (CT) specimens embodying a section of cuspal enamel were subjected to Mode I cyclic or monotonic loads. Cracks were grown in either the forward (from outer enamel inwards) or reverse (from inner enamel outwards) direction and the responses were compared quantitatively. Results showed that the outer enamel exhibits lower resistance to the inception and growth of cracks. Regardless of the growth direction, the near-threshold region of cyclic extension was typical of "short crack" behavior (i.e. deceleration of growth with an increase in crack length). Cyclic crack growth was more stable in the forward direction and occurred over twice the spatial distance achieved in the reverse direction. In response to the monotonic loads, a rising R-curve response was exhibited by growth in the forward direction only. The total energy absorbed in fracture for the forward direction was more than three times that in the reverse. The rise in crack growth resistance was largely attributed to a combination of mechanisms that included crack bridging, crack bifurcation and crack curving, which were induced by decussation in the inner enamel. An analysis of the responses distinguished that the microstructure of enamel appears optimized for resisting crack growth initiating from damage at the tooth's surface.
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Affiliation(s)
- Devendra Bajaj
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, USA
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14
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Xie ZH, Swain MV, Swadener G, Munroe P, Hoffman M. Effect of microstructure upon elastic behaviour of human tooth enamel. J Biomech 2009; 42:1075-80. [PMID: 19345363 DOI: 10.1016/j.jbiomech.2009.02.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Revised: 07/04/2008] [Accepted: 02/11/2009] [Indexed: 11/25/2022]
Abstract
Tooth enamel is the stiffest tissue in the human body with a well-organized microstructure. Developmental diseases, such as enamel hypomineralisation, have been reported to cause marked reduction in the elastic modulus of enamel and consequently impair dental function. We produce evidence, using site-specific transmission electron microscopy (TEM), of difference in microstructure between sound and hypomineralised enamel. Built upon that, we develop a mechanical model to explore the relationship of the elastic modulus of the mineral-protein composite structure of enamel with the thickness of protein layers and the direction of mechanical loading. We conclude that when subject to complex mechanical loading conditions, sound enamel exhibits consistently high stiffness, which is essential for dental function. A marked decrease in stiffness of hypomineralised enamel is caused primarily by an increase in the thickness of protein layers between apatite crystals and to a lesser extent by an increase in the effective crystal orientation angle.
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Affiliation(s)
- Z-H Xie
- Center for Integrated Nanotechnologies, Los Alamos, NM 87545, USA.
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15
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Affiliation(s)
- Adele L Boskey
- Musculoskeletal Integrity Program, Hospital for Special Surgery, 535 East 70th Street, New York, New York 10021, USA.
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16
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Gower LB. Biomimetic model systems for investigating the amorphous precursor pathway and its role in biomineralization. Chem Rev 2008; 108:4551-627. [PMID: 19006398 PMCID: PMC3652400 DOI: 10.1021/cr800443h] [Citation(s) in RCA: 612] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Laurie B Gower
- Department of Materials Science & Engineering, University of Florida, 210A Rhines Hall, Gainesville, Florida 32611, USA.
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17
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Xie Z, Swain M, Munroe P, Hoffman M. On the critical parameters that regulate the deformation behaviour of tooth enamel. Biomaterials 2008; 29:2697-703. [DOI: 10.1016/j.biomaterials.2008.02.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Accepted: 02/19/2008] [Indexed: 11/30/2022]
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18
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Robinson C. Self-oriented assembly of nano-apatite particles: a subunit mechanism for building biological mineral crystals. J Dent Res 2007; 86:677-9. [PMID: 17652193 DOI: 10.1177/154405910708600801] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- C Robinson
- Division of Oral Biology, Leeds Dental Institute, University of Leeds, Clarendon Way, Leeds University LS2 9LU, UK.
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19
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Chen H, Czajka-Jakubowska A, Spencer N, Mansfield J, Robinson C, Clarkson B. Effects of systemic fluoride and in vitro fluoride treatment on enamel crystals. J Dent Res 2007; 85:1042-5. [PMID: 17062747 PMCID: PMC2233794 DOI: 10.1177/154405910608501113] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Systemically administered fluoride at a concentration of 75 ppm increases the surface roughness of developing enamel crystals in rats, which may be significant in advancing our understanding of the biological mechanism of fluorosis. Thus, the aim of this study was to investigate whether the increased surface roughness may be a result of surface restructuring by the direct action of fluoride at the crystal surface. We examined the fluoride dose-dependent roughening of enamel crystal surfaces in vivo, in the rat, and whether this roughening could be mimicked by the in vitro treatment of rat enamel crystals with neutral pH fluoride solutions. Our results showed that enamel crystal surface roughness increased after treatment with increasing fluoride ion concentrations, whether applied in vitro or administered systemically. This suggests a mechanism, alongside others, for the increased surface roughness of crystals in fluorotic enamel.
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Affiliation(s)
- H. Chen
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, 1011 N. University, Ann Arbor, MI 48109-1078, USA
| | - A. Czajka-Jakubowska
- Karol Marcinkowski University of Medical Sciences, Dept. of Conservative Dentistry and Periodontology, Poznań, Poland
| | - N.J. Spencer
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, 1011 N. University, Ann Arbor, MI 48109-1078, USA
| | - J.F. Mansfield
- University of Michigan Electron Microbeam Analysis Laboratory
| | - C. Robinson
- Leeds Dental Institute, Division of Oral Biology, Leeds, England
| | - B.H. Clarkson
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, 1011 N. University, Ann Arbor, MI 48109-1078, USA
- corresponding author,
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20
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Boskey AL, Young MF, Kilts T, Verdelis K. Variation in mineral properties in normal and mutant bones and teeth. Cells Tissues Organs 2006; 181:144-53. [PMID: 16612080 DOI: 10.1159/000091376] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Hydroxyapatite mineral is deposited in an organized fashion in the matrices of bones and teeth. The amount of mineral present, the composition of the mineral, and the size of the mineral crystals varies with both tissue and animal age, diet, health status, and the tissue being examined. Here, we review methods for measuring these differences in mineral properties and provide some illustrations from bones and teeth of animals in which the small leucine-rich proteoglycans (biglycan and decorin) were ablated. Differences in mineral properties between biglycan-deficient bones and teeth are related to the functions of this small proteoglycan in these tissues.
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Affiliation(s)
- Adele L Boskey
- Mineralized Tissue Research Laboratory, Musculoskeletal Integrity Program, Hospital for Special Surgery, New York, NY 10021, USA.
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21
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Robinson C, Connell S, Brookes SJ, Kirkham J, Shore RC, Smith DAM. Surface chemistry of enamel apatite during maturation in relation to pH: implications for protein removal and crystal growth. Arch Oral Biol 2005; 50:267-70. [PMID: 15721160 DOI: 10.1016/j.archoralbio.2004.11.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2004] [Accepted: 11/16/2004] [Indexed: 10/25/2022]
Abstract
Apatite crystal growth rate and morphology in mineralized tissues are considered to be controlled by surface interaction with extracellular matrix proteins. During enamel maturation where protein is finally removed from crystal surfaces to permit massive crystal growth, pH oscillates between approximately 5.8 and approximately 7.2. With this in mind, a study of enamel apatite surface chemistry in terms of local environmental pH was undertaken. Using atomic force microscopy adhesion force measurements were made between hydroxylated or carboxylated cantilever tips and maturation stage crystals between pH 2 and 10. Adhesion force increased from pH 10 to a maximum at pH 6.6 presumably due to increased hydrogen bonding due to replacement of surface cations (Na, Ca, Mg) with protons and/or protonation of phosphate per se. Below pH 6.6 adhesion force decreased and became very variable indicating that the surface had become unstable probably due to removal of fully protonated phosphate from the surface by adherence to the cantilever tip. Frictional force measurements also revealed 2-3, approximately 30 nm diameter high friction domains in bands across the crystal long axis. Their location mirrored the binding pattern of similarly sized amelogenin aggregates seen in vitro. The data suggests that specific protein binding sites may exist on crystal surfaces and may be released at lower pH by protonation which would lower cationic charge on both crystal surface and ionic charge on the protein. Instability of the crystal surface could also play a role.
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Affiliation(s)
- C Robinson
- Division of Oral Biology, Leeds Dental Institute, University of Leeds, UK.
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22
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Chen H, Chen Y, Orr BG, Holl MMB, Majoros I, Clarkson BH. Nanoscale probing of the enamel nanorod surface using polyamidoamine dendrimers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:4168-71. [PMID: 15969412 DOI: 10.1021/la0303005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Although it is known that noncollagenous proteins of dental origin bind to the hydroxyapatite crystal surfaces, no measure of their binding strength has been calculated. This experiment used -COOH-capped generation 7 PAMAM dendrimers as nanoprobes of the biological hydroxyapatite nanorod surfaces. Dendrimer distribution was characterized using AFM. The results showed dendrimers to be spaced at intervals along the c-axis of the crystals. From these observations and assuming a fully ionized -COOH dendrimer, a mathematical model of the binding capacity of the crystal surface with the dendrimer was developed. The Monte Carlo method was used to simulate the binding process between the dendrimer and crystal surface, and the binding strength of the -COOH groups to the surface was calculated to be 90 +/- 20 kJ/mol. These results support the CFM studies which have described alternating bands of charge domains on the crystal surface and that the binding strength will be dependent on both the intensity of the charge on the protein and the crystal surface.
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Affiliation(s)
- Haifeng Chen
- School of Dentistry, Department of Physics, Program in Macromolecular Science and Engineering, Center for Biologic Nanotechnology, University of Michigan, Ann Arbor, Michigan 48109-1078, USA
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23
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Robinson C, Connell S, Kirkham J, Shore R, Smith A. Dental enamel—a biological ceramic: regular substructures in enamel hydroxyapatite crystals revealed by atomic force microscopy. ACTA ACUST UNITED AC 2004. [DOI: 10.1039/b401154f] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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24
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Smith D, Connell S, Robinson C, Kirkham J. Chemical force microscopy: applications in surface characterisation of natural hydroxyapatite. Anal Chim Acta 2003. [DOI: 10.1016/s0003-2670(02)01374-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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25
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Kirkham J, Brookes SJ, Shore RC, Wood SR, Smith D, Zhang J, Chen H, Robinson C. Physico-chemical properties of crystal surfaces in matrix–mineral interactions during mammalian biomineralisation. Curr Opin Colloid Interface Sci 2002. [DOI: 10.1016/s1359-0294(02)00017-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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26
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Wen HB, Fincham AG, Moradian-Oldak J. Progressive accretion of amelogenin molecules during nanospheres assembly revealed by atomic force microscopy. Matrix Biol 2001; 20:387-95. [PMID: 11566273 DOI: 10.1016/s0945-053x(01)00144-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Amelogenin proteins, the principal components of the developing dental enamel matrix, self-assemble to form nanosphere structures that are believed to function as structural components directly involved in the matrix mediated enamel biomineralization. The self-assembly behavior of a recombinant murine amelogenin (rM179) was investigated by atomic force microscopy (AFM) for further understanding the roles of amelogenin proteins in dental enamel biomineralization. Recombinant rM179 amelogenin was dissolved in a pH 7.4 Tris-HCl buffer at concentrations ranging from 12.5 to 300 microg/ml. The solutions were adsorbed on mica, fixed with Karnovsky fixative and rinsed thoroughly with water for atomic force microscopy (AFM). At low concentrations (12.5-50 microg/ml), nanospheres with diameters varying from 7 to 53 nm were identified while at concentrations ranging between 100-300 microg/ml the size distribution was significantly narrowed to be steadily between 10 and 25 nm in diameter. These nanospheres were observed to be the basic building blocks of both engineered rM179 gels and of the developing enamel extracellular matrix. The stable 15-20-nm nanosphere structures generated in the presence of high concentrations of amelogenins were postulated to be of great importance in facilitating the highly organized ultrastructural microenvironment required for the formation of initial enamel apatite crystallites.
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Affiliation(s)
- H B Wen
- Center for Craniofacial Molecular Biology, School of Dentistry, University of Southern California, 2250 Alcazar Street, CSA 1st Floor, Los Angeles, CA 90033, USA
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27
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Aspects of the physical chemistry of polymers, biomaterials and mineralised tissues investigated with atomic force microscopy (AFM). Colloids Surf B Biointerfaces 2000; 19:301-314. [PMID: 11064253 DOI: 10.1016/s0927-7765(00)00139-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Beyond being merely a tool for measuring surface topography, atomic force microscopy (AFM) has made significant contributions to various scientific areas dealing with physical chemistry processes. This paper presents aspects of the physical chemistry at surfaces and interfaces of polymers, biomaterials and tissues investigated with AFM. Selected examples presented include surface induced self-assembly of polymer blends, copolymer interfacial reinforcement of immiscible homopolymers, protein adsorption on biomaterials and erosion of mineralised human tissues. In these areas, AFM is a useful and versatile tool to study structural or dynamic sample properties including thermodynamically driven surface evolution of polymer surfaces, lateral surface composition of interfaces, adsorption processes, and the metrology of demineralisation phenomena.
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28
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Kirkham J, Zhang J, Brookes SJ, Shore RC, Wood SR, Smith DA, Wallwork ML, Ryu OH, Robinson C. Evidence for charge domains on developing enamel crystal surfaces. J Dent Res 2000; 79:1943-7. [PMID: 11201043 DOI: 10.1177/00220345000790120401] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The control of hydroxyapatite crystal initiation and growth during enamel development is thought to be mediated via the proteins of the extracellular matrix. However, the precise nature of these matrix-mineral interactions remains obscure. The aim of the present study was to use a combination of atomic and chemical force microscopy to characterize developing enamel crystal surfaces and to determine their relationship with endogenous enamel matrix protein (amelogenin). The results show regular and discrete domains of various charges or charge densities on the surfaces of hydroxyapatite crystals derived from the maturation stage of enamel development. Binding of amelogenin to individual crystals at physiological pH was seen to be coincident with positively charged surface domains. These domains may therefore provide an instructional template for matrix-mineral interactions. Alternatively, the alternating array of charge on the crystal surfaces may reflect the original relationship with, and influence of, matrix interaction with the crystal surfaces during crystal growth.
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Affiliation(s)
- J Kirkham
- Division of Oral Biology, Leeds Dental Institute, The University of Leeds, UK.
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29
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Finke M, Jandt KD, Parker DM. The Early Stages of Native Enamel Dissolution Studied with Atomic Force Microscopy. J Colloid Interface Sci 2000; 232:156-164. [PMID: 11071745 DOI: 10.1006/jcis.2000.7200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Food-induced demineralization (erosion) is one of the key factors in surface structural changes of tooth enamel, with soft drinks being a significant etiological agent. The objective of this study was to measure early stages of enamel loss with high accuracy on native enamel surfaces combined with qualitative observations of changes in the surface morphology using the atomic force microscope (AFM). Native unerupted third molar surfaces were partly covered with a gold reference layer. Samples were imaged with the AFM before dissolution (at baseline) and after exposure to three different drinks (mineral water, a "toothkind" blackcurrant drink, and a lemon and lime juice drink) at five different exposure times (15 min, 30 min, 1 h, 2 h, and 3 h). The changes in the surface morphology were investigated qualitatively as well as quantitatively. This study showed that the maximum material loss occurred at the aprismatic parts of the enamel close to the perikymata. The maximum enamel loss was greatest for the lemon and lime juice drink and lowest for water. A two-way ANOVA of the transformed data, employing the natural logarithm, showed a statistically significant difference between both the drinks and the exposure time at a 95% confidence level (P=0.000). This demonstrates that the AFM is a suitable tool for measuring early stages of enamel demineralization. Copyright 2000 Academic Press.
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Affiliation(s)
- M Finke
- Department of Oral and Dental Science, Dental Materials Science and Biomaterials Section, University of Bristol, Lower Maudlin Street, Bristol, BS1 2LY, UK
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