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1
Ryabova, Anna V., Anna Yu Fanda, and Sergey V. Trofimov. "Functional Protective Coatings for Steel Architectural Construction Panels." MATEC Web of Conferences 346 (2021): 02041. http://dx.doi.org/10.1051/matecconf/202134602041.
Повний текст джерелаАнотація:
Currently, enameled steel products are becoming very popular in construction, since they have a number of valuable properties that noticeably distinguish enameled architectural and construction panels against the background of other facing building materials. Also, extremely urgent is the problem of obtaining glass enamel coatings for architectural and construction panels with high properties. In the work, glass-crystalline enamel coatings in the system R2O–RO–B2O3–Al2O3–SiO2–TiO2–P2O2–F- were studied, the features of their formation on facing steel panels were revealed. The physicochemical and aesthetic-consumer properties of the developed enamel coatings have been investigated. The influence of the chemical composition of titanium-containing glass and the crystallization process on the whiteness index of white coating glass-crystalline enamels and the characteristic color shade was studied using a spectrophotometric method using an RGB color measurement model. This method made it possible to accurately determine the shades of the obtained glass-crystalline enamel coatings for steel.
2
Lebedeva, Tat’yana V., and Sergey I. Galanin. "DECORATING ENAMEL INSERTS WITH ENAMEL GRANULATION." Technologies & Quality 52, no. 2 (July 2, 2021): 62–67. http://dx.doi.org/10.34216/2587-6147-2021-2-52-62-67.
Повний текст джерелаАнотація:
The results of an experimental study of the combined enamelling technique are presented – enamel with enamel granulation. Original enamel inserts, decorated with enamel granules of various colours and sizes, were obtained, the use of which expands the possibilities of decorative enamelling. It is shown that different degrees of fusion of the enamel grain on the prepared base gives different artistic effects. Spherical grains, qualitatively adhered to the enamel ground, give a more explicit, spectacular relief; focus on specific elements of the pictorial composition. Melted hemispherical grains give a light texture to the composition, support and complement the enamel painting. Recommendations are given on the formation of granulation, preparation of enamel soil, drawing of details, firing temperatures of enamels to obtain high-quality granulation and colourful artistic composition, as well as other technological and design aspects of the decorating process.
3
Seto, Tsz Ho, Anastasiia Grymak, Vidya Mudliar, and Joanne Jung Eun Choi. "Effect of Enamel Bleaching on the Bond Strength of Ceramic—A Systematic Review." Oral 2, no. 2 (June 15, 2022): 182–97. http://dx.doi.org/10.3390/oral2020018.
Повний текст джерелаАнотація:
The increase in aesthetic demands has increased the use of ceramic dental restorations in dentistry. Ceramic restorations are bonded to the tooth structure using adhesives. There is a lack of standard guidelines in terms of post-bleaching time intervals and bond strengths of ceramic restorations. Bleaching products have also been stated to affect the morphology of enamel. Therefore, the purpose of this systematic review is to evaluate the bond strength between ceramic and enamel and the changes in the surface roughness of enamel post teeth bleaching. An electronic search was performed in the databases PubMed, OVID MEDLINE, Scopus, and Web of Science with MESH terms: “adhesion OR bonding”, “ceramic OR ceramics OR dental porcelain”, “tooth bleaching OR teeth bleaching OR tooth whitening OR teeth whitening” and “enamel OR dental enamel OR enamels OR dental enamels”. The articles were screened, and the final selection of articles was obtained by using the inclusion and exclusion criteria. Of the 170 studies identified from the search, only 12 studies met the inclusion criteria and were selected for full-text review. A further search by hand was performed, and additional 48 studies were selected. From the 60 full-text studies, 18 studies met the inclusion criteria and were included for data extraction. The results were based on a descriptive analysis of the effect on bond strength of ceramic to enamel after a bleaching protocol and the changes in the surface roughness of enamel post bleaching protocol. In conclusion, bleaching protocols alter the surface roughness of enamel and, thus, the shear bond strength between ceramic and enamel. Bleaching treatments with a higher concentration of hydrogen peroxide reduce the bond strength between ceramic and enamel. Delaying bonding after bleaching for up to 7 days increases the bond strength between ceramic and enamel.
4
Limeback, H. "Isolation and characterization of pig enamelins." Biochemical Journal 243, no. 2 (April 15, 1987): 385–90. http://dx.doi.org/10.1042/bj2430385.
Повний текст джерелаАнотація:
Enamel proteins were extracted from pig developing enamel by sequential extraction procedures. Two proteins identified as enamelins by slab-gel electrophoresis (Mr 67,000 and 63,000) were separated from amelogenins by gel sieving and ion-exchange chromatography. Their enamelin characteristic was confirmed by hydroxyapatite-binding studies and amino acid analysis. Degradation of extracted enamel proteins was also studied in vitro. The larger of the two enamelins appeared to be resistant to degradation by endogenous enamel proteinases. Hydroxyapatite showed strong binding with the enamelins, but did not prevent the degradation of the Mr-63,000 enamelin. These results indicate that at least one high-Mr enamelin in pig developing enamel is a source of enamelin breakdown products.
5
Kim, J. W., F. Seymen, B. P. J. Lin, B. Kiziltan, K. Gencay, J. P. Simmer, and J. C. C. Hu. "ENAM Mutations in Autosomal-dominant Amelogenesis Imperfecta." Journal of Dental Research 84, no. 3 (March 2005): 278–82. http://dx.doi.org/10.1177/154405910508400314.
Повний текст джерелаАнотація:
To date, 4 unique enamelin gene (ENAM) defects have been identified in kindreds with amelogenesis imperfecta. To improve our understanding of the roles of enamelin in normal enamel formation, and to gain information related to possible genotype/phenotype correlations, we have identified 2 ENAM mutations in kindreds with hypoplastic ADAI, 1 novel (g.4806A>C, IVS6-2A>C) and 1 previously identified (g.8344delG), and have characterized the resulting enamel phenotypes. The IVS6-2A>C mutation caused a severe enamel phenotype in the proband, exhibiting horizontal grooves of severely hypoplastic enamel. The affected mother had several shallow hypoplastic horizontal grooves in the lower anterior teeth. In the case of the g.8344delG mutation, the phenotype was generalized hypoplastic enamel with shallow horizontal grooves in the middle 1/3 of the anterior teeth. In general, mutations in the human enamelin gene cause hypoplastic enamel, often with horizontal grooves, but the severity of the enamel defects is variable, even among individuals with the same mutation.
6
Nagano, T., S. Oida, H. Ando, K. Gomi, T. Arai, and M. Fukae. "Relative Levels of mRNA Encoding Enamel Proteins in Enamel Organ Epithelia and Odontoblasts." Journal of Dental Research 82, no. 12 (December 2003): 982–86. http://dx.doi.org/10.1177/154405910308201209.
Повний текст джерелаАнотація:
Amelogenin, enamelin, sheathlin (ameloblastin/ amelin), enamelysin (MMP-20), and KLK4 (EMSP-1) are the major structural proteins and proteinases in developing tooth enamel. Recently, odontoblasts were reported to express amelogenin, the most abundant enamel protein. In this study, we hypothesized that odontoblasts express all enamel proteins and proteases, and we measured their relative mRNA levels in enamel organ epithelia and odontoblasts associated with porcine secretory- and maturation-stage enamel by RT-PCR, using a LightCycler instrument. The results showed that amelogenin mRNA in secretory-stage EOE is 320-fold higher than in odontoblasts beneath secretory-stage enamel, and over 20,000-fold higher than in odontoblasts under maturation-stage enamel. Similar results were obtained for enamelin and sheathlin. Enamelysin mRNA levels were equivalent in these two tissues, while KLK4 mRNA was higher in odontoblasts than in secretory-stage EOE. These results support the conclusion that odontoblasts are involved in the formation of the enamel layer adjacent to enamel-dentin junction.
7
Farooq, Imran, and Amr Bugshan. "The role of salivary contents and modern technologies in the remineralization of dental enamel: a review." F1000Research 9 (March 9, 2020): 171. http://dx.doi.org/10.12688/f1000research.22499.1.
Повний текст джерелаАнотація:
Human enamel once formed cannot be biologically repaired or replaced. Saliva has a significant role in remineralization of dental enamel. It not only has a buffering capacity to neutralize the oral cavity’s low pH generated after acidic encounters, but also acts as a carrier of essential ions, such as fluoride, calcium and phosphate, which have a positive role in enamel’s remineralization. This review discusses how salivary contents, like proteins and enzymes, have a natural role in enamel’s mineralization. In addition, the presence of ions, such as fluoride, calcium and phosphate, in saliva further enhances its capability to remineralize the demineralized enamel surface. The review further examines modern innovative technologies, based on biomimetic regeneration systems, including dentin phosphoproteins, aspartate-serine-serine, recombinant porcine amelogenin, leucine-rich amelogenin peptide and nano-hydroxyapatite, that promote enamel remineralization. Fluoride boosters like calcium phosphates, polyphosphates, and certain natural products can also play an important role in enamel remineralization.
8
Farooq, Imran, and Amr Bugshan. "The role of salivary contents and modern technologies in the remineralization of dental enamel: a narrative review." F1000Research 9 (June 15, 2021): 171. http://dx.doi.org/10.12688/f1000research.22499.3.
Повний текст джерелаАнотація:
Human enamel once formed cannot be biologically repaired or replaced. Saliva has a significant role in remineralization of dental enamel. It not only has a buffering capacity to neutralize the oral cavity’s low pH generated after acidic encounters, but also acts as a carrier of essential ions, such as fluoride, calcium and phosphate, which have a positive role in enamel’s remineralization. This review discusses how salivary contents, like proteins and enzymes, have a natural role in enamel’s mineralization. In addition, the presence of ions, such as fluoride, calcium and phosphate, in saliva further enhances its capability to remineralize the demineralized enamel surface. The review further examines modern innovative technologies, based on biomimetic regeneration systems, including dentin phosphoproteins, aspartate-serine-serine, recombinant porcine amelogenin, leucine-rich amelogenin peptide and nano-hydroxyapatite, that promote enamel remineralization. Fluoride boosters like calcium phosphates, polyphosphates, and certain natural products can also play an important role in enamel remineralization.
9
Farooq, Imran, and Amr Bugshan. "The role of salivary contents and modern technologies in the remineralization of dental enamel: a narrative review." F1000Research 9 (April 1, 2020): 171. http://dx.doi.org/10.12688/f1000research.22499.2.
Повний текст джерелаАнотація:
Human enamel once formed cannot be biologically repaired or replaced. Saliva has a significant role in remineralization of dental enamel. It not only has a buffering capacity to neutralize the oral cavity’s low pH generated after acidic encounters, but also acts as a carrier of essential ions, such as fluoride, calcium and phosphate, which have a positive role in enamel’s remineralization. This review discusses how salivary contents, like proteins and enzymes, have a natural role in enamel’s mineralization. In addition, the presence of ions, such as fluoride, calcium and phosphate, in saliva further enhances its capability to remineralize the demineralized enamel surface. The review further examines modern innovative technologies, based on biomimetic regeneration systems, including dentin phosphoproteins, aspartate-serine-serine, recombinant porcine amelogenin, leucine-rich amelogenin peptide and nano-hydroxyapatite, that promote enamel remineralization. Fluoride boosters like calcium phosphates, polyphosphates, and certain natural products can also play an important role in enamel remineralization.
10
Koenigswald von, Wighart, and Francisco Goin. "Enamel differentiation in South American marsupials and a comparison of placental and marsupial enamel." Palaeontographica Abteilung A 255, no. 4-6 (January 31, 2000): 129–68. http://dx.doi.org/10.1127/pala/255/2000/129.
Повний текст джерела
11
MORADIAN-OLDAK, Janet, Wendy LEUNG, James P. SIMMER, Margarita ZEICHNER-DAVID, and Alan G. FINCHAM. "Identification of a novel proteinase (ameloprotease-I) responsible for the complete degradation of amelogenin during enamel maturation." Biochemical Journal 318, no. 3 (September 15, 1996): 1015–21. http://dx.doi.org/10.1042/bj3181015.
Повний текст джерелаАнотація:
During enamel formation the proteins of the extracellular matrix, particularly amelogenins, are removed prior to maturation. In order to investigate this process and to improve our understanding of the function of proteinases during enamel maturation, proteinase fractions were isolated from developing pig enamel and assayed for proteolytic activity in vitro. A recombinant murine amelogenin, M179, was used as a substrate. Two major groups of enamel proteinases were defined as high-molecular-mass [‘high-molecular-weight’ in Moradian-Oldak, Simmer, Sarte, Zeichner-David and Fincham (1994) Arch. Oral Biol. 39, 647–656] and low-molecular-mass proteinases. Here we report the characterization of one of the proteinases present in the low-molecular-mass group. We demonstrate that this proteinase is a serine proteinase capable of degradation of M179 following cleavage of the tyrosine-rich amelogenin polypeptide from the N-terminal region. A partial N-terminal sequence of the proteinase was obtained (LPHVPHRIPPGYGRPXTXNEEGXNPYFXFFXXHG). An anti-peptide antibody directed against a synthetic peptide corresponding to the first 14 amino acids of the above sequence was produced. The presence of the proteinase in the acetic acid extract was confirmed by Western blotting. Searching using the amino acid sequence determined in this study showed it to be also present in the 32 kDa and 89 kDa enamelin proteins reported by Fukae, Tanabe, Murakami and Tohi [(1996) Adv. Dent. Res., in the press]. We therefore identify the 32 kDa enamelin as an enamel proteinase (‘ameloprotease-I’) which is responsible for amelogenin degradation in maturing enamel. We propose that the 89 kDa enamelin is a precursor of ameloprotease-I, the first enamel protein for which a function has been defined.
12
Santos, Maria Cristina Leme Godoy dos, and Sergio Roberto Peres Line. "The genetics of amelogenesis imperfecta: a review of the literature." Journal of Applied Oral Science 13, no. 3 (September 2005): 212–17. http://dx.doi.org/10.1590/s1678-77572005000300002.
Повний текст джерелаАнотація:
A melogenesis imperfecta (AI) is a group of inherited defects of dental enamel formation that show both clinical and genetic heterogeneity. Enamel findings in AI are highly variable, ranging from deficient enamel formation to defects in the mineral and protein content. Enamel formation requires the expression of multiple genes that transcribes matrix proteins and proteinases needed to control the complex process of crystal growth and mineralization. The AI phenotypes depend on the specific gene involved, the location and type of mutation, and the corresponding putative change at the protein level. Different inheritance patterns such as X-linked, autosomal dominant and autosomal recessive types have been reported. Mutations in the amelogenin, enamelin, and kallikrein-4 genes have been demonstrated to result in different types of AI and a number of other genes critical to enamel formation have been identified and proposed as candidates for AI. The aim of this article was to present an evaluation of the literature regarding role of proteins and proteinases important to enamel formation and mutation associated with AI.
13
Bartlett, John D. "Dental Enamel Development: Proteinases and Their Enamel Matrix Substrates." ISRN Dentistry 2013 (September 16, 2013): 1–24. http://dx.doi.org/10.1155/2013/684607.
Повний текст джерелаАнотація:
This review focuses on recent discoveries and delves in detail about what is known about each of the proteins (amelogenin, ameloblastin, and enamelin) and proteinases (matrix metalloproteinase-20 and kallikrein-related peptidase-4) that are secreted into the enamel matrix. After an overview of enamel development, this review focuses on these enamel proteins by describing their nomenclature, tissue expression, functions, proteinase activation, and proteinase substrate specificity. These proteins and their respective null mice and human mutations are also evaluated to shed light on the mechanisms that cause nonsyndromic enamel malformations termed amelogenesis imperfecta. Pertinent controversies are addressed. For example, do any of these proteins have a critical function in addition to their role in enamel development? Does amelogenin initiate crystallite growth, does it inhibit crystallite growth in width and thickness, or does it do neither? Detailed examination of the null mouse literature provides unmistakable clues and/or answers to these questions, and this data is thoroughly analyzed. Striking conclusions from this analysis reveal that widely held paradigms of enamel formation are inadequate. The final section of this review weaves the recent data into a plausible new mechanism by which these enamel matrix proteins support and promote enamel development.
14
FAN, HONGYI, SHANSHAN GAO, YANG LIU, ZHUOLI ZHU, and HAIYANG YU. "THE MICROMECHANICAL AND TRIBOLOGICAL FEATURE OF MILD MOTTLED ENAMEL." Journal of Mechanics in Medicine and Biology 14, no. 04 (July 3, 2014): 1450050. http://dx.doi.org/10.1142/s021951941450050x.
Повний текст джерелаАнотація:
The relationships between the basic mechanical and wear properties of mottled enamel, especially during the mastication process, are important factors and must be explored. This study evaluated mottled enamel's micro-tribological behavior under artificial saliva conditions in vitro. The basic mechanical properties were determined by nanoindentiation testing. A conical diamond nanoindenter tip was used to scratch mottled enamel and normal enamel. The scratches were sliding with a constant normal load of 2 mN, with different cycles during the tests. The hardness, elastic modulus and friction coefficient were obtained to analyze the mechanical properties. The results showed that the hardness and elastic modulus of mottled enamel were 10% and 14.6% less, respectively, than those of normal enamel. Mottled enamel showed a lower friction coefficient and a higher wear rate, compared to normal enamel. The friction coefficient did not appear to be related to the wear rate for either type of enamel. The wear mechanism for normal enamel was plastic deformation for early wear, while the combination of plastic deformation and delamination was the main damage feature of mottled enamel.
15
Kim, Jung-Ho, Oh-Won Kwon, Hyung-Il Kim, and Yong Hoon Kwon. "Acid Resistance of Erbium-doped Yttrium Aluminum Garnet Laser–Treated and Phosphoric Acid–Etched Enamels." Angle Orthodontist 76, no. 6 (November 1, 2006): 1052–56. http://dx.doi.org/10.2319/11405-398.
Повний текст джерелаАнотація:
Abstract Objective: To compare the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser ablation and of phosphoric acid etching on the in vitro acid resistance of bovine enamel. Materials and Methods: Teeth were polished to make the surface flat. The polished enamel was either etched with 37% phosphoric acid for 30 seconds or ablated with a single 33 J/cm2 pulse from an Er:YAG laser. The control specimens were free from acid etching and laser ablation. Changes in crystal structure, dissolved mineral (calcium [Ca] and phosphorus [P]) contents, and calcium distribution in the enamel subsurface after a pH-cycling process were evaluated. Results: After laser treatment, poor crystal structures improved without forming any new phases, such as tricalcium phosphates. Among the tested enamels, dissolved mineral contents were significantly different (P < .05). Er:YAG laser–treated enamels had the lowest mineral dissolution (Ca, 13.78 ppm; P, 6.33 ppm), whereas phosphoric acid–etched enamels had the highest (Ca, 15.90 ppm; P, 7.33 ppm). The reduction rate and reduced depth of calcium content along the subsurface were lowest in Er:YAG laser–treated enamels. Conclusion: The Er:YAG laser–treated enamels are more acid resistant to acid attack than phosphoric acid–etched enamels.
16
Klimova, L. V., A. V. Ryabova, and V. V. Kerimova. "Chemically Resistant Glass-Enamel Coating for the Protection of Steel Pipelines." Materials Science Forum 992 (May 2020): 598–604. http://dx.doi.org/10.4028/www.scientific.net/msf.992.598.
Повний текст джерелаАнотація:
At present, the problem of obtaining a defect-free corrosion-resistant glass-enamel coating for steel pipelines is extremely urgent. In this paper, the development of a corrosion-resistant glass-enamel coating for steel pipelines is presented, as well as the technical and operational properties of synthesized glass-enamel coatings are investigated. The composition of the enamel coating is developed, which has a high adhesion index, chemical resistance to aggressive media and can be recommended for introduction in the production of enameled pipes.
17
Reis, Signo, Mike Koenigstein, Liang Fan, Genda Chen, Luka Pavić, and Andrea Moguš-Milanković. "The Effects of Silica on the Properties of Vitreous Enamels." Materials 12, no. 2 (January 13, 2019): 248. http://dx.doi.org/10.3390/ma12020248.
Повний текст джерелаАнотація:
Ground coat enamels for low carbon steel that contain silica as a mill addition have been developed to study the changes of their properties. Acid-resistant commercial enamel where silica addition was varied from 0 to 10.0 wt % was used for this investigation. The effects of the addition on the corrosion resistance, thermal properties, electrical properties, and mechanical adherence of the enamel to low carbon steel were studied. The corrosion resistance of the steel enameled coupons was tested using a salt spray (fog) apparatus for time periods reaching 168 h at room temperature. It was found that, although the density was not affected, the adherence decreased with an increase in silica content. As expected, the silica addition decreased the coefficient of thermal expansion, which is directly related to the increasing stress between the glass and steel in accordance with the adherence results. A mill addition of 7.5 wt% of silica to the samples was sufficient to obtain adequate enamel adherence and good corrosion resistance. Furthermore, the addition of silica influenced the electrical conductivity and dielectric permittivity measurements at room temperature and the conductivity measured in a wide frequency range (1 Hz–1 MHz). The dielectric permittivity measured at 1 MHz showed decrease after the addition of up to 7.5 wt% of silica.
18
Shi, Zhuoyue. "Advances in biomimetic mineralization of tooth enamel based on cell-free strategies." MATEC Web of Conferences 363 (2022): 01032. http://dx.doi.org/10.1051/matecconf/202236301032.
Повний текст джерелаАнотація:
Tooth enamel is a highly-mineralized hard tissue covering the outermost layer of the dental crown, and amelogenesis is inseparable from the participation of necessary components such as ameloblasts, organic matrix proteins, and mineral ions, such as Ca2+ and PO43-. However, mature enamel is an acellular tissue and it is difficult to self-repair once damaged. The current treatment methods for enamel damage are filling or repairing with alloys, ceramics, or composite resins. However, the mechanical properties of these materials are quite different from the natural enamel and they can’t ensure a completely closed interface with the remaining enamel surface, which usually causes a series of post-repair problems. At present, the biomimetic mineralization of tooth enamel is a research hotspot in the field of prosthodontics, and has great clinical application needs and prospects, especially the researches on cell-free strategies have made significant accomplishment. Here, based on the cell-free strategies, we review the recent knowledge from ex situ and in situ two dimensions in the remineralization of tooth ename.
19
Bartlett, J. D., and J. P. Simmer. "Proteinases in Developing Dental Enamel." Critical Reviews in Oral Biology & Medicine 10, no. 4 (July 1999): 425–41. http://dx.doi.org/10.1177/10454411990100040101.
Повний текст джерелаАнотація:
For almost three decades, proteinases have been known to reside within developing dental enamel. However, identification and characterization of these proteinases have been slow and difficult, because they are present in very small quantities and they are difficult to purify directly from the mineralizing enamel. Enamel matrix proteins such as amelogenin, ameloblastin, and enamelin are cleaved by proteinases soon after they are secreted, and their cleavage products accumulate in the deeper, more mature enamel layers, while the full-length proteins are observed only at the surface. These results suggest that proteinases are necessary for "activating" enamel proteins so the parent proteins and their cleavage products may perform different functions. A novel matrix metalloproteinase named enamelysin (MMP-20) was recently cloned from tooth tissues and was later shown to localize primarily within the most recently formed enamel. Furthermore, recombinant porcine enamelysin was demonstrated to cleave recombinant porcine amelogenin at virtually all of the sites that have previously been described in vivo. Therefore, enamelysin is at least one enzyme that may be important during early enamel development. As enamel development progresses to the later stages, a profound decrease in the enamel protein content is observed. Proteinases have traditionally been assumed to degrade the organic matrix prior to its removal from the enamel. Recently, a novel serine proteinase named enamel matrix serine proteinase-1 (EMSP1) was cloned from enamel organ epithelia. EMSP1 localizes primarily to the early maturation stage enamel and may, therefore, be involved in the degradation of proteins prior to their removal from the maturing enamel. Other, as yet unidentified, proteinases and proteinase inhibitors are almost certainly present within the forming enamel and await discovery.
20
Roig-Vanaclocha, Ana, María Fernanda Solá-Ruiz, Juan Luis Román-Rodríguez, José Amengual-Lorenzo, Jorge Alonso Pérez-Barquero, and Rubén Agustín-Panadero. "Dental Treatment of White Spots and a Description of the Technique and Digital Quantification of the Loss of Enamel Volume." Applied Sciences 10, no. 12 (June 25, 2020): 4369. http://dx.doi.org/10.3390/app10124369.
Повний текст джерелаАнотація:
The prevalence of white spots on teeth has increased in recent years. Regardless of their etiology, these lesions are characterized by a reduction in the enamel’s mineral phase, which is replaced by organic fluids. This causes an alteration of its chemical composition that affects its optical characteristics. Subsurface demineralization increases the pore volume of enamel, which in turn changes its optical refraction and results in the opaque color of white spot lesions. Here, we examined a non-invasive clinical technique used for eliminating these white spot lesions from enamel via two HCl-based products at different concentrations (6.6% and 15%). We used a digital method for evaluating the volumetric changes produced in dental enamel by the application of both products, one of which involved chemical erosion and the other, abrasive erosion. The mean volume of the enamel eliminated was −0.042 mm in 15% HCl, and −0.12 mm in 6.6% HCl. Thus, both 15% HCl and 6.6% HCl are capable of eroding the surface of the tooth enamel without reaching dentin. Moreover, 6.6% HCl produced a greater erosion of the dental enamel and left the surface a texture typical of an abrasive chemical-erosive product. The 15% HCl, however, produced an etching pattern typical of an erosive chemical with open enamel prisms prepared for subsequent adhesive procedures and restorers.
21
Pugach, M. K., Y. Li, C. Suggs, J. T. Wright, M. A. Aragon, Z. A. Yuan, D. Simmons, A. B. Kulkarni, and C. W. Gibson. "The Amelogenin C-Terminus Is Required for Enamel Development." Journal of Dental Research 89, no. 2 (December 30, 2009): 165–69. http://dx.doi.org/10.1177/0022034509358392.
Повний текст джерелаАнотація:
The abundant amelogenin proteins are responsible for generating proper enamel thickness and structure, and most amelogenins include a conserved hydrophilic C-terminus. To evaluate the importance of the C-terminus, we generated transgenic mice that express an amelogenin lacking the C-terminal 13 amino acids (CTRNC). MicroCT analysis of TgCTRNC29 teeth (low transgene number) indicated that molar enamel density was similar to that of wild-type mice, but TgCTRNC18 molar enamel (high transgene number) was deficient, indicating that extra transgene copies were associated with a more severe phenotype. When amelogenin-null (KO) and TgCTRNC transgenic mice were mated, density and volume of molar enamel from TgCTRNCKO offspring were not different from those of KO mice, indicating that neither TgCTRNC18 nor TgCTRNC29 rescued enamel’s physical characteristics. Because transgenic full-length amelogenin partially rescues both density and volume of KO molar enamel, it was concluded that the amelogenin C-terminus is essential for proper enamel density, volume, and organization.
22
Zamojda, Elzbieta, Karolina Orywal, Barbara Mroczko, and Teresa Sierpinska. "Trace Elements in Dental Enamel Can Be a Potential Factor of Advanced Tooth Wear." Minerals 13, no. 1 (January 15, 2023): 125. http://dx.doi.org/10.3390/min13010125.
Повний текст джерелаАнотація:
Enamel is the outermost layer of the tooth and has no ability to regenerate after tooth eruption. Its mineral composition is likely to be responsible for the enamel resistance to any agents that appear in oral cavity. The objective of this study was to compare the content of Ca, Mg, Zn and Cu in specific layers of healthy and worn tooth enamel. Three groups of dental enamel samples were analyzed. The amounts of Ca, Mg and Zn in the enamel bioptates were established using atomic absorption spectroscopy after an acid biopsy technique had been applied. The concentration of Cu was established using an electrothermic method with an AA spectrometer. The analysis was carried out using parametric tests (the Pearson’s linear correlation coefficient and the t-test for the correlation coefficient). Results: A statistically significant difference was confirmed between the mean amount of zinc in severely worn dentition and all the layers in vitro and in vivo. Strong positive relationships between magnesium and zinc contents were shown at some depths. A significant difference was registered between the amount of copper in the severely worn dentitions compared to the superficial layer of the healthy teeth in vitro and in vivo. Conclusion: It appears that zinc metabolism may play an important role in enamel formation and may influence enamel’s resistance to wear after tooth eruption.
23
PAVKIN, DMITRIY YU. "STUDY OF THE PROPERTIES OF STEEL ENAMELED SURFACE FOR SILO TOWERS." Agricultural engineering, no. 2 (2022): 46–51. http://dx.doi.org/10.26897/2687-1149-2022-2-46-51.
Повний текст джерелаАнотація:
One of the technologies for obtaining and storing high-quality silage and haylage is the use of silo towers. The authors propose to manufacture silo towers from high-strength and corrosion-resistant steel sheets, coated with glass enamel, which has a lower coefficient of sliding friction than steel and concrete, as well as high resistance to aggressive environments. The aim of the study was to determine the properties of the glass-enamel coating of steel parts for the manufacturing of tower-type storages. A glass-enamel coating from a frit of glass-enamel brand MK-5 was applied to prepared sheets of steel 09G2S using a spray gun. The total thickness of the enameled coating ranged from 200 to 350 nm. Steel sheets were baked at a temperature of 850°C for 30 minutes. The thickness of the enamel coating was determined with an Olympus GX51 microscope. The roughness was determined using a TAYLOR HOBSON Surtronic 25 profilometer. The adhesive properties of the coating were studied using a Positest AT-M adhesive meter. Each test piece was tested twice. The tests were carried out on a sheet of 0.06 m2. The coefficient of sliding friction was determined on an adapted test bench. Laboratory tests with silage mass were carried out according to the developed methodology. Studies of the steel surface with a glass-enamel coating showed that the average thickness of the enameled layer was 690 nm, the roughness was 0.01 μm, and the adhesion was 5.25 MPa. The sliding friction coefficient of sliced plant materials on the enameled steel surface was 0.15, which is 2.6 and 3.2 times lower than that of non-enamelled steel and concrete, respectively. The authors have made conclusions about the possibility of using steel 09G2S in silo towers as a suitable sustitute for steel 65G and the sufficient efficiency of the chosen enameling technology.
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PAVKIN, DMITRIY YU. "STUDY OF THE PROPERTIES OF STEEL ENAMELED SURFACE FOR SILO TOWERS." Agricultural engineering, no. 2 (2022): 46–51. http://dx.doi.org/10.26897/2687-1149-2022-2-46-51.
Повний текст джерелаАнотація:
One of the technologies for obtaining and storing high-quality silage and haylage is the use of silo towers. The authors propose to manufacture silo towers from high-strength and corrosion-resistant steel sheets, coated with glass enamel, which has a lower coefficient of sliding friction than steel and concrete, as well as high resistance to aggressive environments. The aim of the study was to determine the properties of the glass-enamel coating of steel parts for the manufacturing of tower-type storages. A glass-enamel coating from a frit of glass-enamel brand MK-5 was applied to prepared sheets of steel 09G2S using a spray gun. The total thickness of the enameled coating ranged from 200 to 350 nm. Steel sheets were baked at a temperature of 850°C for 30 minutes. The thickness of the enamel coating was determined with an Olympus GX51 microscope. The roughness was determined using a TAYLOR HOBSON Surtronic 25 profilometer. The adhesive properties of the coating were studied using a Positest AT-M adhesive meter. Each test piece was tested twice. The tests were carried out on a sheet of 0.06 m2. The coefficient of sliding friction was determined on an adapted test bench. Laboratory tests with silage mass were carried out according to the developed methodology. Studies of the steel surface with a glass-enamel coating showed that the average thickness of the enameled layer was 690 nm, the roughness was 0.01 μm, and the adhesion was 5.25 MPa. The sliding friction coefficient of sliced plant materials on the enameled steel surface was 0.15, which is 2.6 and 3.2 times lower than that of non-enamelled steel and concrete, respectively. The authors have made conclusions about the possibility of using steel 09G2S in silo towers as a suitable sustitute for steel 65G and the sufficient efficiency of the chosen enameling technology.
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Caterina, John J., Ziedonis Skobe, Joanne Shi, Yanli Ding, James P. Simmer, Henning Birkedal-Hansen, and John D. Bartlett. "Enamelysin (Matrix Metalloproteinase 20)-deficient Mice Display an Amelogenesis Imperfecta Phenotype." Journal of Biological Chemistry 277, no. 51 (October 21, 2002): 49598–604. http://dx.doi.org/10.1074/jbc.m209100200.
Повний текст джерелаАнотація:
Enamelysin is a tooth-specific matrix metalloproteinase that is expressed during the early through middle stages of enamel development. The enamel matrix proteins amelogenin, ameloblastin, and enamelin are also expressed during this same approximate developmental time period, suggesting that enamelysin may play a role in their hydrolysis. In support of this interpretation, recombinant enamelysin was previously demonstrated to cleave recombinant amelogenin at virtually all of the precise sites known to occurin vivo. Thus, enamelysin is likely an important amelogenin-processing enzyme. To characterize thein vivobiological role of enamelysin during tooth development, we generated an enamelysin-deficient mouse by gene targeting. Although mice heterozygous for the mutation have no apparent phenotype, the enamelysin null mouse has a severe and profound tooth phenotype. Specifically, the null mouse does not process amelogenin properly, possesses an altered enamel matrix and rod pattern, has hypoplastic enamel that delaminates from the dentin, and has a deteriorating enamel organ morphology as development progresses. Our findings demonstrate that enamelysin activity is essential for proper enamel development.
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Hu, J. C. C., and Y. Yamakoshi. "Enamelin and Autosomal-dominant Amelogenesis Imperfecta." Critical Reviews in Oral Biology & Medicine 14, no. 6 (November 2003): 387–98. http://dx.doi.org/10.1177/154411130301400602.
Повний текст джерелаАнотація:
Dental enamel forms as a progressively thickening extracellular layer by the action of proteins secreted by ameloblasts. The most abundant enamel protein is amelogenin, which is expressed primarily from a gene on the X-chromosome (AMELX). The two most abundant non-amelogenin enamel proteins are ameloblastin and enamelin, which are expressed from the AMBN and ENAM genes, respectively. The human AMBN and ENAM genes are located on chromosome 4q13.2. The major secretory products of the human AMELX, AMBN, and ENAM genes have 175, 421, and 1103 amino acids, respectively, and are all post-translationally modified, secreted, and processed by proteases. Mutations in AMELX have been shown to cause X-linked amelogenesis imperfecta (AI), which accounts for 5% of AI cases. Mutations in ENAM cause a severe form of autosomal-dominant smooth hypoplastic AI that represents 1.5%, and a mild form of autosomal-dominant local hypoplastic AI that accounts for 27% of AI cases in Sweden. The discovery of mutations in the ENAM gene in AI kindreds proved that enamelin is critical for proper dental enamel formation and that it plays a role in human disease. Here we review how enamelin was discovered, what is known about enamelin protein structure, post-translational modifications, processing by proteases, and its potentially important functional properties such as its affinity for hydroxyapatite and influence on crystal growth in vitro. The primary structures of human, porcine, mouse, and rat enamelin are compared, and the human enamelin gene, its structure, chromosomal localization, temporal and spatial patterns of expression, and its role in the etiology of amelogenesis imperfecta are discussed.
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Bondarenko, N., and Z. Pavlenko. "STUDYING THE POSSIBILITY OF USING COLEMANIT TO OBTAIN ENAMELS ON STEEL." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 5, no. 10 (November 5, 2020): 57–62. http://dx.doi.org/10.34031/2071-7318-2020-5-10-57-62.
Повний текст джерелаАнотація:
The practical use of boron and its compounds is extremely diverse due to its different properties. About 55 % of boron raw materials are consumed by the glass and ceramic industries for the manufacture of optical glasses, heat-insulating glass fibers, acid-resistant and refractory products, enamels, glazes, porcelain, etc. The paper considers the possibility of using colemanite to obtain enamel over steel. The optimal temperature-time regime of firing has been developed to obtain a high-quality coating and achieve the desired effect. It has been established that colemanite can partially replace cover enamel drill. On the basis of the studies carried out, it was found that the obtained experimental enamel is more refractory than the ESP-210 enamel. The optimal firing temperature for the experimental coating was established – 950 ° С, for the ESP-210 coating – 825 ° С. For uniform reflow of the experimental coating, a temperature is required that exceeds the reflow temperature of ESP-210 by 125 ° C. Colemanite-containing batch was cooked. Cooking was carried out in an electric oven at 1300 ° C for 5 hours. For further research, a slip was prepared from the experimental enamel and applied by pouring onto the plates
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Bartlett, John D., Ziedonis Skobe, Antonio Nanci, and Charles E. Smith. "Matrix metalloproteinase 20 promotes a smooth enamel surface, a strong dentino-enamel junction, and a decussating enamel rod pattern." European Journal of Oral Sciences 119 (December 2011): 199–205. http://dx.doi.org/10.1111/j.1600-0722.2011.00864.x.
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Kelly, Ariana M., Anna Kallistova, Erika C. Küchler, Helena F. Romanos, Andrea Lips, Marcelo C. Costa, Adriana Modesto, and Alexandre R. Vieira. "Measuring the Microscopic Structures of Human Dental Enamel Can Predict Caries Experience." Journal of Personalized Medicine 10, no. 1 (February 2, 2020): 5. http://dx.doi.org/10.3390/jpm10010005.
Повний текст джерелаАнотація:
Objectives: The hierarchical structure of enamel gives insight on the properties of enamel and can influence its strength and ultimately caries experience. Currently, past caries experience is quantified using the decayed, missing, filled teeth/decayed, missing, filled surface (DMFT/DMFS for permanent teeth; dmft/dmfs for primary teeth), or international caries detection and assessment system (ICDAS) scores. By analyzing the structure of enamel, a new measurement can be utilized clinically to predict susceptibility to future caries experience based on a patient’s individual’s biomarkers. The purpose of this study was to test the hypothesis that number of prisms by square millimeter in enamel and average gap distance between prisms and interprismatic areas, influence caries experience through genetic variation of the genes involved in enamel formation. Materials and Methods: Scanning electron microscopy (SEM) images of enamel from primary teeth were used to measure (i) number of prisms by square millimeter and interprismatic spaces, (ii) prism density, and (iii) gap distances between prisms in the enamel samples. The measurements were tested to explore a genetic association with variants of selected genes and correlations with caries experience based on the individual’s DMFT+ dmft score and enamel microhardness at baseline, after an artificial lesion was created and after the artificial lesion was treated with fluoride. Results: Associations were found between variants of genes including ameloblastin, amelogenin, enamelin, tuftelin, tuftelin interactive protein 11, beta defensin 1, matrix metallopeptidase 20 and enamel structure variables measured (number of prisms by square millimeter in enamel and average gap distance between prisms and interprismatic areas). Significant correlations were found between caries experience and microhardness and enamel structure. Negative correlations were found between number of prisms by square millimeter and high caries experience (r value= −0.71), gap distance between prisms and the enamel microhardness after an artificial lesion was created (r value= −0.70), and gap distance between prisms and the enamel microhardness after an artificial lesion was created and then treated with fluoride (r value= −0.81). There was a positive correlation between number of prisms by square millimeter and prism density of the enamel (r value = 0.82). Conclusions: Our data support that genetic variation may impact enamel formation, and therefore influence susceptibility to dental caries and future caries experience. Clinical Relevance: The evaluation of enamel structure that may impact caries experience allows for hypothesizing that the identification of individuals at higher risk for dental caries and implementation of personalized preventative treatments may one day become a reality.
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Pessoa-Lima, Caroline, Jonas Tostes-Figueiredo, Natalia Macedo-Ribeiro, Annie Schmaltz Hsiou, Fellipe Pereira Muniz, José Augusto Maulin, Vinícius H. Franceschini-Santos, et al. "Structure and Chemical Composition of ca. 10-Million-Year-Old (Late Miocene of Western Amazon) and Present-Day Teeth of Related Species." Biology 11, no. 11 (November 8, 2022): 1636. http://dx.doi.org/10.3390/biology11111636.
Повний текст джерелаАнотація:
Molecular information has been gathered from fossilized dental enamel, the best-preserved tissue of vertebrates. However, the association of morphological features with the possible mineral and organic information of this tissue is still poorly understood in the context of the emerging area of paleoproteomics. This study aims to compare the morphological features and chemical composition of dental enamel of extinct and extant terrestrial vertebrates of Crocodylia: Purussaurus sp. (extinct) and Melanosuchus niger (extant), and Rodentia: Neoepiblema sp. (extinct) and Hydrochoerus hydrochaeris (extant). To obtain structural and chemical data, superficial and internal enamel were analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (SEM-EDS). Organic, mineral, and water content were obtained using polarizing microscopy and microradiography on ground sections of four teeth, resulting in a higher organic volume than previously expected (up to 49%). It is observed that both modern and fossil tooth enamel exhibit the same major constituents: 36.7% Ca, 17.2% P, and 41% O, characteristic of hydroxyapatite. Additionally, 27 other elements were measured from superficial enamel by inductively coupled mass spectrometry (ICP-MS). Zinc was the most abundant microelement detected, followed by Pb, Fe, Mg, and Al. Morphological features observed include enamel rods in the rodent teeth, while incremental lines and semiprismatic enamel were observed in the alligator species. The fossil enamel was in an excellent state for microscopic analyses. Results show that all major dental enamel’s physical, chemical, and morphological features are present both in extant and extinct fossil tooth enamel (>8.5 Ma) in both taxa.
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Deutsch, D., A. Palmon, L. W. Fisher, N. Kolodny, J. D. Termine, and M. F. Young. "Sequencing of bovine enamelin (“tuftelin”) a novel acidic enamel protein." Journal of Biological Chemistry 266, no. 24 (August 1991): 16021–28. http://dx.doi.org/10.1016/s0021-9258(18)98510-8.
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Goleus, V. I., T. I. Nahorna, R. I. Kyslychna, and S. Yu Naumenko. "Protective and decorative properties of titanium glass enamels." Voprosy Khimii i Khimicheskoi Tekhnologii, no. 6 (December 2020): 33–37. http://dx.doi.org/10.32434/0321-4095-2020-133-6-33-37.
Повний текст джерелаАнотація:
It is known that enamel coatings with enhanced protective and decorative properties can be fabricated on the basis of boron-silicate glass frits with an increased content of TiO2 in their composition. Opacity and white color of enamel coatings are due to their crystallization at firing temperatures. Titanium glass enamels are not pure white visually, and show yellow and blue shades depending on their chemical composition. The purpose of this work was to establish the influence of basic components on the water resistance and color characteristics of titanium enamel coatings. Our experimental study was focused on the glass frits with the chemical composition described by the generalized formula (76–n–m)SiO2nB2O3mNa2O24MexOy, where MexOy is the total content of TiO2, ZrO2, Al2O3, MgO, СaO, P2O5, and K2O. It was found that the glass frits with the following content of basic components (mol.%): Na2O 12–13, K2O 3, B2O3 10–11, SiO2 49–51 demonstrated the highest water-resistant properties. The color characteristics of titanium enamel coatings prepared on the basis of the mentioned glass frits differ significantly from the reference white light A; the titanium enamel coatings under consideration have a yellow-green tint. The highest deviations of the enamel coating color purity and color tone from a standard of white color were observed when increasing the Na2O content in the glass frits composition at the expense of SiO2. The color of titanium coatings with the highest water resistance has a deviation from the standard of white color within 4–6%.
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Søvik, Jenny B., Alexandre R. Vieira, A. B. Tveit, and Aida Mulic. "Enamel Formation Genes Associated with Dental Erosive Wear." Caries Research 49, no. 3 (2015): 236–42. http://dx.doi.org/10.1159/000369565.
Повний текст джерелаАнотація:
Dental erosive wear is a multifactorial condition that is greatly affected by environmental factors. So far, no study has investigated how dental erosive wear is influenced by variations in enamel formation genes. The aim of the present study was to investigate polymorphisms in genes involved in enamel formation and their influence on enamel susceptibility to dental erosion. DNA samples were collected from 795 Norwegian adolescents aged 16-18 years. Five single-nucleotide polymorphism markers were genotyped in selected candidate genes (ameloblastin, amelogenin, enamelin, tuftelin 1 and tuftelin interacting protein 11), reported to influence enamel formation. Allele and genotype frequencies were compared within two patient groups with dental erosions; all participants with dental erosion and only those with severe dental erosion (erosion extending into dentine). Overrepresentation of the G allele of the enamelin marker was seen in the erosion group compared to the unaffected group (p = 0.047). When erosion severity was considered, statistical significant difference in allele frequency was observed for amelogenin, with the C allele suggesting a protective role (p = 0.02). A suggestive overrepresentation of the TT genotype of the amelogenin marker was also seen in cases with severe erosion (p = 0.049) when compared to cases with no dentine erosion. Amelogenin was also associated with severe erosion in the recessive model; the TT genotype was significantly more frequent in the affected group than in the unaffected group (p = 0.01). The present study suggests that polymorphisms in enamel formation genes are statistically associated with an individual's susceptibility to dental erosive wear.
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Ryabova, Anna V., A. Yu Fanda, Elena A. Yatsenko, and Ming Gin Lee. "Development of Compositions of New Enamel Coatings with Various Operational and Decorative Properties to Protect Steel Architectural and Construction Panels." Materials Science Forum 1037 (July 6, 2021): 684–92. http://dx.doi.org/10.4028/www.scientific.net/msf.1037.684.
Повний текст джерелаАнотація:
Metal enameling is widely used in construction, which differs enameled products from other building materials: the ability to obtain a variety of colors and surfaces; resistance of the surface under the influence of the atmosphere and sunlight; high corrosion resistance; light weight, lightness and quick installation; fire resistance; ease of cleaning; the possibility of mechanizing the manufacture of parts in serial production. The authors of the article have developed the compositions of enamel coatings and investigated their aesthetic and consumer and technical and operational properties. Also, three compositions of new enamel coatings for architectural and construction panels have been developed and enamel coatings of various colors, including pastel colors, have been obtained on their basis.
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Shin, Nah-Young, Hajime Yamazaki, Elia Beniash, Xu Yang, Seth S. Margolis, Megan K. Pugach, James P. Simmer, and Henry C. Margolis. "Amelogenin phosphorylation regulates tooth enamel formation by stabilizing a transient amorphous mineral precursor." Journal of Biological Chemistry 295, no. 7 (January 9, 2020): 1943–59. http://dx.doi.org/10.1074/jbc.ra119.010506.
Повний текст джерелаАнотація:
Dental enamel comprises interwoven arrays of extremely long and narrow crystals of carbonated hydroxyapatite called enamel rods. Amelogenin (AMELX) is the predominant extracellular enamel matrix protein and plays an essential role in enamel formation (amelogenesis). Previously, we have demonstrated that full-length AMELX forms higher-order supramolecular assemblies that regulate ordered mineralization in vitro, as observed in enamel rods. Phosphorylation of the sole AMELX phosphorylation site (Ser-16) in vitro greatly enhances its capacity to stabilize amorphous calcium phosphate (ACP), the first mineral phase formed in developing enamel, and prevents apatitic crystal formation. To test our hypothesis that AMELX phosphorylation is critical for amelogenesis, we generated and characterized a hemizygous knockin (KI) mouse model with a phosphorylation-defective Ser-16 to Ala-16 substitution in AMELX. Using EM analysis, we demonstrate that in the absence of phosphorylated AMELX, KI enamel lacks enamel rods, the hallmark component of mammalian enamel, and, unlike WT enamel, appears to be composed of less organized arrays of shorter crystals oriented normal to the dentinoenamel junction. KI enamel also exhibited hypoplasia and numerous surface defects, whereas heterozygous enamel displayed highly variable mosaic structures with both KI and WT features. Importantly, ACP-to-apatitic crystal transformation occurred significantly faster in KI enamel. Secretory KI ameloblasts also lacked Tomes' processes, consistent with the absence of enamel rods, and underwent progressive cell pathology throughout enamel development. In conclusion, AMELX phosphorylation plays critical mechanistic roles in regulating ACP-phase transformation and enamel crystal growth, and in maintaining ameloblast integrity and function during amelogenesis.
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Nanci, A., M. Bendayan, and H. C. Slavkin. "Enamel protein biosynthesis and secretion in mouse incisor secretory ameloblasts as revealed by high-resolution immunocytochemistry." Journal of Histochemistry & Cytochemistry 33, no. 11 (November 1985): 1153–60. http://dx.doi.org/10.1177/33.11.4056379.
Повний текст джерелаАнотація:
Mouse secretory ameloblasts express a number of enamel proteins, which have been divided into amelogenin and enamelin subfamilies. We have used polyclonal antibodies to murine amelogenins to reveal enamel proteins in mouse ameloblasts using the protein A-gold immunocytochemical technique. Specific immunolabeling was detected over the extracellular enamel matrix and over the rough endoplasmic reticulum, the saccules of the Golgi apparatus, and the secretory granules of the ameloblasts. In addition, some lysosome-like granules were also labeled. Only background labeling was obtained over mitochondria, nuclei, cytosol, adjacent odontoblasts, and dentin. Quantitation of the intensity of labeling showed the presence of an increasing gradient along the secretory pathway, which may correspond to the concentration or the maturation of these proteins as they are processed by the cell. These findings indicate that the ameloblast displays an intracellular distribution of its secretory products similar to that of other merocrine secreting cells. The presence of enamel proteins in lysosomes suggests that crinophagy and/or resorption occurs in these cells.
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Uppal, Dr Ranjit Singh, Dr Atamjit Singh Dr. Atamjit Singh, Dr Rajbir Kaur, and Dr Navdeep Kaur Sodhi. "Enamel Matrix Derivative: An effective regenerative modality (A Literature Review)." International Journal of Scientific Research 2, no. 7 (June 1, 2012): 323–25. http://dx.doi.org/10.15373/22778179/july2013/109.
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Moggi-Cecchi, J., S. Crovella, Antonella Bari, and Paola Gonella. "Enamel hypoplasias in a 19th century population from Northern Italy." Anthropologischer Anzeiger 51, no. 2 (June 9, 1993): 123–29. http://dx.doi.org/10.1127/anthranz/51/1993/123.
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Fischer, Valentin L., Daniela E. Winkler, Robert Głogowski, Thomas Attin, Jean-Michel Hatt, Marcus Clauss, and Florian Wegehaupt. "Species-specific enamel differences in hardness and abrasion resistance between the permanent incisors of cattle (Bos primigenius taurus) and the ever-growing incisors of nutria (Myocastor coypus)." PLOS ONE 17, no. 3 (March 17, 2022): e0265237. http://dx.doi.org/10.1371/journal.pone.0265237.
Повний текст джерелаАнотація:
Hypselodont (ever-growing) teeth of lagomorphs or rodents have higher wear rates (of a magnitude of mm/week), with compensating growth rates, compared to the non-ever-growing teeth of ungulates (with a magnitude of mm/year). Whether this is due to a fundamental difference in enamel hardness has not been investigated so far. We prepared enamel samples (n = 120 per species) from incisors of cattle (Bos primigenius taurus) and nutria (Myocastor coypus, hypselodont incisors) taken at slaughterhouses, and submitted them to indentation hardness testing. Subsequently, samples were split into 4 groups per species (n = 24 per species and group) that were assessed for abrasion susceptibility by a standardized brush test with a control (no added abrasives) and three treatment groups (using fine silt at 4 ±1 μm particle size, volcanic ash at 96 ±9 μm, or fine sand at 166 ±15 μm as abrasives), in which enamel abrasion was quantified as height loss by before-and-after profilometry. The difference in enamel hardness between the species was highly significant, with nutria enamel achieving 78% of the hardness of cattle enamel. In the control and the fine sand group, no enamel height loss was evident, which was attributed to the in vitro system in the latter group, where the sand particles were brushed out of the test slurry by the brushes’ bristles. For fine silt and volcanic ash, nutria enamel significantly lost 3.65 and 3.52 times more height than cattle. These results suggest a relationship between enamel hardness and susceptibility to abrasion. However, neither the pattern within the species nor across the species indicated a monotonous relationship between hardness and height loss; rather, the difference was due to qualitative step related to species. Hence, additional factors not measured in this study must be responsible for the differences in the enamel’s susceptibility to abrasion. While the in vitro brush system cannot be used to rank abrasive test substances in terms of their abrasiveness, it can differentiate abrasion susceptibility in dental tissue of different animal species. The results caution against considering enamel wear as a similar process across mammals.
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Deutsch, D., A. Palmon, J. Catalano-Sherman, and R. Laskov. "Production of Monoclonal Antibodies Against Enamelin and Against Amelogenin Proteins of Developing Enamel Matrix." Advances in Dental Research 1, no. 2 (December 1987): 282–88. http://dx.doi.org/10.1177/08959374870010021801.
Повний текст джерелаАнотація:
The extracellular matrix of developing enamel contains two major classes of proteins, the hydrophobic proline-rich amelogenins and the acidic serine-, glycine-, and aspartic-rich enamelins. These proteins have been postulated as playing a major role in the mineralization and structural organization of developing enamel. To identify and further characterize these different proteins and their possible role in this complex process of biological mineralization, we have in recent years been concerned with the production of specific probes for these proteins. Previously, we have reported on the successful production of specific polyclonal antibodies against enamelin proteins, which did not cross-react with amelogenins, and against amelogenin proteins, which did not cross-react with enamelins (Deutsch et al., 1986, 1987). We now report the production of monoclonal antibodies against a major bovine amelogenin protein (28 kDa) and against a major bovine enamelin protein (66 kDa). One monoclonal antibody against amelogenin and one against enamelin are described. The results showed that the monoclonal antibody against the amelogenin protein reacted strongly with the 28-kDa amelogenin protein band but did not cross-react with enamelins, and the one against the enamelin protein reacted with the 66-kDa enamelin protein but did not cross-react with amelogenins. These monoclonal antibodies provide a specific and powerful tool to distinguish between and further characterize these different classes of proteins, and to improve our understanding of the process of enamel formation.
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Li, Haoxiang, Guangjun He, Qinghe Song, Haiting Xia, Zhiqiang Liu, Jing Liang, and Ting Li. "The Study of Tooth Erosion Tested by the Color Digital Holography (CDH) Detection System." Applied Sciences 12, no. 17 (August 28, 2022): 8613. http://dx.doi.org/10.3390/app12178613.
Повний текст джерелаАнотація:
This study presents a color digital holography (CDH) detection system that includes the optical path and a numerical calculation program to detect tooth erosion under different acid-etching conditions. Etched cattle enamel samples were pressurized within the elastic interval, and the CDH detection system was used to rebuild the three-dimensional deformation field of these samples. Young’s modulus of these samples was employed to evaluate the mechanical properties of enamels by statistical methods. The results show that Young’s modulus of enamel decreases with the increase in etching time, while it decreases slightly with the increase in the etching temperature, and the etching temperature has no effect on the non-etched enamels. Moreover, the detection process proves the CDH detection system has the advantages of high precision, full-field detection, and being non-destructive, fast, and stable. It is expected to have broad application potential for CDH detection systems in the detection of tooth erosion.
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Gupta, Shubh Prabhat, Prashant P. Shetty, Karthik Reddy, and Pankaj Sancheti. "Enamel Hypoplasia: A Case Report." Journal of Advanced Oral Research 5, no. 1 (January 2014): 10–13. http://dx.doi.org/10.1177/2229411220140103.
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CROLL, THEODORE P., and MARK L. HELPIN. "Enamel Microabrasion: A New Approach." Journal of Esthetic and Restorative Dentistry 12, no. 2 (March 2000): 64–71. http://dx.doi.org/10.1111/j.1708-8240.2000.tb00202.x.
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Sato, K., M. Hattori, and T. Aoba. "Disturbed Enamel Mineralization in a Rat Incisor Model." Advances in Dental Research 10, no. 2 (November 1996): 216–24. http://dx.doi.org/10.1177/08959374960100021701.
Повний текст джерелаАнотація:
Possession of full-thickness hard enamel appears to be one of the indispensable life-saving characteristics of rats. Previous studies by Suga and his colleagues and by others demonstrated that various types of malformation are evoked in continuously erupting rat incisors. In the current report, we directed our effort to oversee various types of enamel malformation caused experimentally in rat incisors. We surveyed the specimens collected by Suga and his colleagues, as well as specimens we obtained. From the results, it is conceivable that perturbation of the programmed sequential events during enamel development is a major factor in the establishment of enamel malformation. Animal studies with either 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) or a multidentate phosphonic acid (EDTPO) confirmed that dentin mineralization provides a certain inductive effect on the secretion of enamel matrix and subsequent enamel crystallization. Our recent studies using anti-microtubular agents led to the conclusion that the acceleration of mineralization in outer enamel is a type of enamel malformation, most likely due to disruption of the cellular regulation of calcium transport under severe toxic regimens. In future work, experimental approaches combining measurements of kinetic factors with static observation of enamel lesions are required before we can gain a comprehensive understanding of the pathogenesis of disturbed enamel mineralization. The kinetic factors to be considered include the rates of tissue apposition and tooth eruption which determine the total volume of tooth substance formed, and the rate of mineral accretion. Furthermore, information as to the composition, crystallinity, solubility, and mechanical properties of enamel defects is needed before we can assess the susceptibility of teeth having those lesions to caries and other physico-chemical attacks in the oral environment.
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Rojas-Sánchez, F., M. Alaminos, A. Campos, H. Rivera, and M. C. Sánchez-Quevedo. "Dentin in Severe Fluorosis: a Quantitative Histochemical Study." Journal of Dental Research 86, no. 9 (September 2007): 857–61. http://dx.doi.org/10.1177/154405910708600910.
Повний текст джерелаАнотація:
Dentin responds to different alterations in the enamel with hypermineralization, and is a biomarker of fluoride exposure. We hypothesized that severe fluorosis would lead to hypermineralization of the dentin when the enamel was severely affected. We used scanning electron microscopy and quantitative electron-probe microanalysis to compare dentin and enamel from healthy and fluorotic teeth. The dentin in fluorotic teeth was characterized by a highly mineralized sclerotic pattern, in comparison with control teeth (p < 0.001) and fluorotic enamel lesions (p < 0.001). Enamel near the lesions showed hypercalcification in comparison with dentin (p < 0.001). In response to the effects of severe fluorosis in the enamel, the dentin showed hypermineralization, as found in other enamel disorders. The hypermineralization response of the dentin in our samples suggests that the mechanism of the response should be taken into account in dental caries and other dental disorders associated with severe fluorosis.
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Bouropoulos, N., and J. Moradian-Oldak. "Induction of Apatite by the Cooperative Effect of Amelogenin and the 32-kDa Enamelin." Journal of Dental Research 83, no. 4 (April 2004): 278–82. http://dx.doi.org/10.1177/154405910408300402.
Повний текст джерелаАнотація:
Extracellular matrix proteins are considered to play essential roles in controlling the nucleation, growth, and organization of hydroxyapatite crystals during enamel formation. The effects of amelogenin and the 32-kDa enamelin proteins on apatite nucleation were investigated by a steady-state gel diffusion device containing 10% gelatin gels loaded with 0, 0.75%, and 1.5% (w/w) native porcine amelogenins. It was found that the induction time for hydroxyapatite precipitation was strongly increased by the presence of amelogenins, suggesting an inhibitory effect of apatite nucleation. Addition of 18 μg/mL of 32-kDa enamelin to 10% gelatin also caused inhibition of nucleation. Remarkably, addition of 18 and 80 μg/mL of 32-kDa enamelin in gels containing 1.5% amelogenin accelerated the nucleation process in a dose-dependent manner. Our observations strongly suggest that the 32-kDa enamelin and amelogenins cooperate to promote nucleation of apatite crystals and propose a possible novel mechanism of mineral nucleation during enamel biomineralization.
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Tyukanko, Vitaliy, Alexandr Demyanenko, Antonina Dyuryagina, Kirill Ostrovnoy, and Gulsim Aubakirova. "Optimizing the Composition of Silicone Enamel to Ensure Maximum Aggregative Stability of Its Suspensions Using Surfactant Obtained from Oil Refining Waste." Polymers 14, no. 18 (September 13, 2022): 3819. http://dx.doi.org/10.3390/polym14183819.
Повний текст джерелаАнотація:
The aim of this study was to optimize the composition of enamel consisting of aluminum pigment and polyphenylsiloxane polymer, in order to achieve the maximum aggregative stability of suspensions. Sedimentation rate (SR) was used as a criterion for assessing the aggregative stability of the suspensions. An original product, AS-1, and industrial additives PEPA and Telaz, were tested as surfactants. AS-1 was obtained from oil refining waste at M. Kozybayev North Kazakhstan University. All the studied surfactants improved the stability of the suspensions. The AS-1 additive significantly improved the stability of the suspensions, but exhibited a lower stabilizing ability by 10–20% than PEPA. The maximum overall stability of the suspensions was recorded at a PEPA level of 0.25–0.375 g/dm3 in the enamel. The Taguchi method was used to optimize the composition of the enamel, using AS-1 as the surfactant. It is recommended to use AS-1 in silicone enamels. Optimum compositions can reduce the petrol absorption of coatings by 1.5 times, their roughness by 2.5 times and increase their gloss.
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Kierdorf, U., and H. Kierdorf. "A Scanning Electron Microscopic Study on Surface Lesions in Fluorosed Enamel of Roe Deer (Capreolus capreolus L.)." Veterinary Pathology 26, no. 3 (May 1989): 209–15. http://dx.doi.org/10.1177/030098588902600304.
Повний текст джерелаАнотація:
Scanning electron microscopy of surface enamel lesions in fluorosed permanent premolars and molars of free-ranging Roe deer revealed two types of pits. Post-eruptive lesions that resulted from mechanical stress on hypomineralized enamel during mastication were characterized by steep walls and a typical honeycomb structure on their bottom, a result of fracture of enamel rods; holes left by fractured rods were surrounded by interred enamel. Pits of developmental origin (hypoplasias), either as shallow depressions of enamel surfaces or narrow holes running deep into the enamel, were characterized by convex, rounded walls covered by numerous Tomes' process pits. Pits of hypoplastic and post-eruptive origin were often found in the same tooth. Intact enamel surfaces of fluorosed teeth resembled that of controls.
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Risnes, S. "Ectopic Tooth Enamel. An SEM Study of the Structure of Enamel in Enamel Pearls." Advances in Dental Research 3, no. 2 (September 1989): 258–64. http://dx.doi.org/10.1177/08959374890030022701.
Повний текст джерелаАнотація:
Eighteen human molars with enamel pearls ranging in diameter from 0.8 to 2.7 mm were sectioned, acid-etched, and processed for SEM observation. In addition to pearl enamel, the specimens contained crown enamel for comparison. All pearls were of the composite type. The enamel layer reached maximal thicknesses of between 0.3 and 0.7 mm opposite the tip of the dentinal cone. The enamel structure was normal, but more variable and irregular than crown enamel. The prism course was often irregular throughout the whole thickness of enamel. Distinct Hunter-Schreger bands were absent. Prisms and interprism were occasionally difficult to identify as separate entities. The packing of crystals seemed to be less tight in pearl enamel. The scarcity of Retzius lines was attributed to the method of preparation. Prism cross-striations with a periodicity ranging between 1.3 and 4.5 μm were frequently encountered. A superficial prism-free zone with a regular 1.7-2.5-μm striation was present in localized regions of many pearls. The formation time of a medium-sized pearl was calculated to be about 11.5 months. A variety of cross-cut prism configurations was observed. Occasional hypoplastic lesions and hypomineralized areas were encountered. In conclusion, pearl enamel possesses most of the structural attributes of crown enamel, but in general its organization seems to be less orderly. Enamel pearls represent developmental disturbances in position and timing more than in structure.
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Seymen, Figen, and Basak Kiziltan. "Amelogenesis imperfecta: a scanning electron microscopic and histopathologic study." Journal of Clinical Pediatric Dentistry 26, no. 4 (July 1, 2002): 327–35. http://dx.doi.org/10.17796/jcpd.26.4.3348743513089434.
Повний текст джерелаАнотація:
Amelogenesis imperfecta (AI) is a hereditary defect in enamel formation affecting both primary and permanent dentition. Scanning electron microscopic investigation is one of the most effective methods in diagnosing and identifying the type of amelogenesis imperfecta. The aim of this study was to investigate the ultrastructure of different types of amelogenesis imperfecta enamel. The primary teeth of three children with AI aged 4, 10 and 11-years-old were studied by scanning electron microscopy and irregular enamel, irregularities in enamel crystallites, hypoplastic areas on the enamel surface were seen. Histopathological evaluation revealed predentin areas with irregular canaliculi between normal dentin and internal resorption areas in the pulp tissue. Conclusively, in amelogenesis imperfecta, enamel tissue is mostly affected besides minor defects in dentinal and pulpal tissue.