Synthetic Enamel Research Articles

Synthetic Enamel Could Make Teeth Stronger and Smarter

Synthetic Enamel Could Make Teeth Stronger and Smarter

CLOROFILA EXTRAÍDA DE RESÍDUO INDUSTRIAL DA ERVA-MATE (Ilex paraguaiensis) UMA POSSIBILIDADE DE ECONOMIA CIRCULAR

CHLOROPHYLL EXTRACTED FROM INDUSTRIAL WASTE FROM MATE-HERB (Ilex paraguaiensis) A POSSIBILITY OF CIRCULAR ECONOMY. Chlorophyll is the most abundant green pigment on the planet, it is unstable and decomposes naturally. Mate-herb is a traditional native plant in the southern region of South America, and its tea is part of the local culture and extractive agriculture. The mate-herb industry generates as a by-product a resinous material rich in chlorophyll whose use is proposed to be a natural pigment. The chlorophyll extraction method uses ethanol as a solvent; its structural modification leads to the obtainment of derivatives like pheophytin, Co-pheophytin, Ni-pheophytin, and Zn-pheophytin. The samples were analyzed by electronic (VISIBLE) and vibrational (FTIR) spectroscopy, and energy-dispersive X-ray fluorescence spectrometry (EDXRF). Color analysis (CIE L*a*b*) was performed by decomposition in grayscale and the classification of the samples by the supervised machine learning (ML) algorithm Random Forest (RF), showing adequate accuracy for this type of matrix. The pigments were dispersed in synthetic enamel paint to study color stability when exposed to lighting. It was verified that Co-pheophytin and Ni-pheophytin are the most stable. The chlorophyll extracted from the resin presents an economically viable use for residues from mate-herb industries, whose family farmers benefit, with the bias of environmental and social sustainability, within the circular economy.

Synthetic tooth enamel has bite

Scientists have created a new synthetic material with the properties of tooth enamel, setting the stage for advances in tooth repair or replacement (Nature 2017, DOI: 10.1038/nature21410). Tooth enamel from all species has a similar structure: microsized ceramic columns in a soft protein matrix. An international team led by Nicholas A. Kotov of the University of Michigan, Ann Arbor, prepared arrays of micrometer-scale zinc oxide columns to form “nanowire carpets.” Then the researchers embedded the columns in a polyallylamine matrix. They built up the material by repeating the process, adding more layers of the polymer-impregnated columns on top of each other. The material has a collection of properties—stiffness, density, and vibrational damping—that are similar to or better than those of tooth enamel and that haven’t been combined in one synthetic material before. More work needs to be done to scale up to the size of teeth without defects. But, the

Sudanese traditional stains for staining some biological samples

Taifta, cloth dye and paints were considered as one of the Sudanese colours that was extracted from Sudanese rocks; it used to colour traditional handworks such as Palm Sunday (local name; saaf), prayers carpets while the second dye used to stain clothes in addition to the third one ElMohandis paints (water base painting) that used for synthetic enamel and emulsion paints. All those dyes were used in this study to stain some bacteriological smears in addition to blood films to study the possibility of using these stains in the future to stain some medical samples in case of safe stain, ruler areas to avoid travels cost, good staining, availability of stain, and low cost too. In this study, we have used different staining colours with the different procedures to study the possibility of staining of some biological samples with those traditional Sudanese dyes; beside ability to uses those stains in the future to stain other kind of biological samples such as histopathological samples, in cosmetics, medical tabs and also to colour food.

Enamel regeneration - current progress and challenges.

Dental Enamel is the outermost covering of teeth. It is hardest mineralized tissue present in the human body. Enamel faces the challenge of maintaining its integrity in a constant demineralization and remineralization within the oral environment and it is vulnerable to wear, damage, and decay. It cannot regenerate itself, because it is formed by a layer of cells that are lost after the tooth eruption. Conventional treatment relies on synthetic materials to restore lost enamel that cannot mimic natural enamel. With advances in material science and understanding of basic principles of organic matrix mediated mineralization paves a way for formation of synthetic enamel. The knowledge of enamel formation and understanding of protein interactions and their gene products function along with the isolation of postnatal stem cells from various sources in the oral cavity, and the development of smart materials for cell and growth factor delivery, makes possibility for biological based enamel regeneration. This article will review the recent endeavor on biomimetic synthesis and cell based strategies for enamel regeneration.

Enamel surface remineralization: Using synthetic nanohydroxyapatite

Objective:The purpose of this study was to evaluate the effects of synthetically processed hydroxyapatite particles in remineralization of the early enamel lesions in comparison with 2% sodium fluoride.Materials and Methods:Thirty sound human premolars were divided into nanohydroxyapatite group (n = 15) and the sodium fluoride group (n = 15). The specimens were subjected to demineralization before being coated with 10% aqueous slurry of 20 nm nanohydroxyapatite or 2% sodium fluoride. The remineralizing efficacy of the materials was evaluated using surface microhardness (SMH) measurements, scanning microscopic analysis and analysis of the Ca/P ratio of the surface enamel. Data analysis was carried out using paired t-test and independent t-test.Results:The results showed that the nanohydroxyapatite group produced a surface morphology close to the biologic enamel, the increase in mineral content (Ca/P ratio) was more significant in the nanohydroxyapatite group (P < 0.05) and the SMH recovery was closer to the baseline level in the nanohydroxyapatite group (P < 0.05). Both the groups did not show any significant difference in thickness (P > 0.05).Conclusion:The use of biomimetic nanohydroxyapatite as a remineralizing agent holds promise as a new synthetic enamel biocompatible material to repair early carious lesions.

Synthetic tooth enamel: SEM characterization of a fluoride hydroxyapatite coating for dentistry applications

An alternative to etching enamel for retention of an adhesive is to grow crystals on the enamel surface. The potential advantages of crystal growth include easy procedure and less damage to the enamel. These crystals retain the adhesive or are the actual dental restoration. In this work, a paste of synthetic enamel was used to grow crystals of fluoride hydroxyapatite (F-HA) onto the human tooth surface. This technique can be used for several dentistry applications like enamel whitening, strengthening and restoration of early carie lesions. The low cost of reagents and simplicity of the technique along with the biocompatibility of the paste render possible the utilization on the market. The samples were prepared through the application of the paste by the incremental technique. The results obtained by scanning electron microscope (SEM)/EDX have indicated the deposition of a homogeneous layer of calcium phosphate that was grown onto the enamel substrate. The average thickness of the deposited film was in the range of 50-100 µm and with a similar density from the natural enamel observed by radiographic images.

Nucleation and growth of hydroxyapatite nanocrystals for nondestructive repair of early caries lesions

Characterization of synthetic enamel formed by newly developed dental paste for repairing early caries lesions was performed using scanning and transmission electron microscopies and atomic force microscopy, with the chemical composition analysis using X-ray photoelectron spectroscopy. It was shown that the hydroxyapatite nanocrystals seamlessly grew in the interface between the paste and tooth enamel, and arranged their (0 0 0 1) face parallel to the tooth surface same as enamel apatite. The rapid growth of high crystalline large hydroxyapatite crystals by applying the paste is attributed to the dissociation of calcium phosphate clusters, Ca 9(PO 4) 6, which is the main growth unit of hydroxyapatite when it grows under physiological conditions, to ionic species in the concentrated and low pH phosphate solution.

Synthetic enamel could silence dentists’ drills

Seamless fixing of an early caries lesion has been achieved without prior dental excavation.

Synthetic Tooth Enamel

Synthetic Tooth Enamel

A synthetic enamel for rapid tooth repair

The conventional treatment of dental caries involves mechanical removal of the affected part and filling of the hole with a resin or metal alloy. But this method is not ideal for tiny early lesions because a disproportionate amount of healthy tooth must be removed to make the alloy or resin stick. Here we describe a dental paste of synthetic enamel that rapidly and seamlessly repairs early caries lesions by nanocrystalline growth, with minimal wastage of the natural enamel.

Measurements of elastic properties of some coating materials

Corrosion and erosion on metallic substrates are prevented using coatings of primers and paints consecutively. The paint and primer should adhere well on to the metallic surfaces in the form of thin films. These adherent films are not always long-lasting. Elastic properties of films made of red oxide primers and polyurethane-based synthetic enamel paints were measured. The measurements included the modulus of elasticity, Poisson’s ratio, and strain energy. If taken into account, these findings may ultimately lead to improved primer-paint systems for the surfaces.

Mossbauer studies of stannous fluoride reactivity with synthetic tooth enamel: A model for the tooth cavity protection actions of novel dentifrices

SnF2 is an important toothpaste ingredient, added for the provision of clinical efficacy for hard and soft tissue diseases and in breath protection. Synthetic calcium hydroxyapatite powders were exposed to liquid supernates (25 w/w% toothpaste water slurries, centrifuged) of Crest Gum Care® (SnF2) dentifrice. One-minute treatments were followed by 3x water washing, centrifugation and lyophilization. Post treatment, powders were analyzed by Mossbauer spectroscopy with 0.5–1 gram of treated apatite powder. Results show that tooth mineral stannous fluoride interactions include: (1) formation of surface reaction products with both Sn(II) and Sn(IV) oxidation states; (2) Sn-F binding on mineral surfaces with no evidence of SnO. The surface binding is, however, not pure Sn-F but contains contributions of other ligands, probably oxygens from surface phosphates or hydroxyl groups. Results also suggest that surface reacted stannous tin is oxidized with time, even when bound as a layer on the tooth surface. This study demonstrates for the first time the presence of Sn-F on tooth enamel post treatment and the contribution of passivation to long term stannous chemistry on tooth surfaces. The study also illustrates the practical applications of the Mossbauer technique.

Degradative Changes in Whole Enamel Homogenates Incubated In Vitro in the Presence of Low Calcium Ion Concentrations

The purpose of this study was to investigate overall degradative changes occurring to enamel matrix proteins in small, freeze-dried pieces of rat incisor enamel homogenized and incubated directly for 0–48 hours in a synthetic enamel fluid solution (165 mM total ionic strength with 0.153 mM calcium chloride) versus other samples homogenized and incubated for the same time intervals in distilled water. The results indicated that many alterations in the apparent molecular weights of enamel matrix proteins took place under both conditions although the rates for many degradative changes over a 48 hour period were often slower in distilled water than in synthetic enamel fluid. Freeze-dried enamel samples homogenized and incubated in 165 mM Tris-HCl buffer at pH 8.0 showed changes comparable to those seen with distilled water. This suggested that differences observed between samples incubated in enamel fluid versus distilled water were unrelated to pH or ionic strength of the solutions and may be the result of a requirement by some enamel proteinases for small amounts of free calcium ions in incubation media. Of interest were findings that some enamel matrix proteins, especially those in strips taken from the first half of the secretory stage of amelogenesis, were degraded much faster in distilled water than in synthetic enamel fluid. The reasons for this effect are unclear although, in this case, calcium ions could be inhibitory to hydrolysis of certain matrix proteins by the enamel proteinases.

Enzyme Compartmentalization during Biphasic Enamel Matrix Processing

Processing of enamel matrix proteins is essentially biphasic. Secretory stage metallo-protease activity generates a discrete, presumably functional, spectrum of molecules which may also undergo dephosphorylation. Maturation stage serine proteases almost completely destroy the matrix. The present aim was to examine the tissue compartmentalization of these enzyme activities in relation to their possible function. A sequential extraction using synthetic enamel fluid, phosphate buffer and SDS was used to identify enzymes free in the enamel fluid, crystal bound or aggregated with the bulk matrix respectively. Results indicated that the metallo-proteases and alkaline phosphatase were free in the secretory stage enamel fluid while the serine proteases appeared to be largely bound to the maturation stage crystals. The mobility of the metallo-proteases and alkaline phosphatase would ensure efficient initial processing of secretory matrix, while the largely mineral bound serine proteases would ensure retention of protease activity despite massive destruction and protein removal.

Crystal growth in dental enamel: the role of amelogenins and albumin.

Amelogenin-mineral interactions were investigated using an in vitro binding approach. Rat incisor enamel matrix proteins (mainly amelogenins) were dissolved in synthetic enamel fluid and allowed to equilibrate with deproteinised developing enamel crystals. The results showed that amlogenin proteins of 21, 23, 24, 26 and 27-kDa (corresponding to nascent and partially degraded amelogenins) were associated with the crystals whilst the lower Mr amelogenins (< 21 KDa) remained free in the synthetic enamel fluid. These data suggest the nascent and partially degraded amelogenins may interact with developing enamel crystals and could influence their growth. Albumin-mineral interactions were investigated by extracting developing rat incisor enamel with synthetic enamel fluid. Insoluble material (including the enamel crystals) was then further extracted with 0.1 M phosphate buffer (pH 7.4) to desorb any mineral bound proteins. Western blotting using anti-albumin antibodies showed that almost all of the albumin from the secretory stage enamel and a significant proportion of the albumin present in early transition stage was extractable in the synthetic enamel fluid. However, synthetic enamel fluid did not extract albumin from late transition or maturation stage tissue, which could only be removed following further extraction with phosphate buffer. Albumin degradation was apparent during the transition and maturation stages, where it is degraded and ultimately removed. This binding pattern may be related to amelogenin degradation and removal during the transition stage, permitting albumin access to the previously obscured crystal surfaces. That the secretory stage matrix appears to "protect" secretory stage crystals from albumin may be an important consideration in the aetiology of enamel hypoplasias (i.e. incomplete crystal growth) and when using dissociative extraction procedures for the identification of mineral bound proteins.

Developmental changes in the pH of enamel fluid and its effects on matrix-resident proteinases.

The objectives of this study were to measure pH in developing enamel at progressively older (more mature) stages of amelogenesis in vivo, and then to formulate synthetic enamel fluid mixtures that approximated these pH values for in vitro studies. The ultimate goal was to characterize the molecular weights of proteinases visualized by enzymograms incubated in synthetic enamel fluid using gelatin and casein as substrates. For most experiments, the proteinases were extracted en masse from small freeze-dried enamel strips directly into a non-reducing sample preparation buffer. In some experiments, we pre-treated the enamel strips with acetic acid to determine if this common method for demineralization and protein extraction caused any changes in the activity levels of the enamel proteinases. In other experiments, we first soaked enamel strips in synthetic enamel fluid to determine solubility of the proteinases within an aqueous phase. The results indicated that the pH of developing enamel remained fairly constant near pH 7.23 across the secretory stage, but it was generally more acidic (6.93) and fluctuated in focal areas between mildly acidic (6.2-6.8) and near-neutral (7.2) conditions across the maturation stage. The pH then slowly rose to near 7.35 when the enamel was almost mature (hard). The acidic conditions were generally inhibitory to most enamel proteinases, but there were some caseinase activities in mid-maturation-stage enamel near 23-30 kDa which appeared to be activated by weakly acidic conditions (pH 6.28). Pre-treatment of enamel samples with 0.5 M acetic acid markedly altered the overall profile of enamel proteinases, causing activation of some latent proteinase activities and permanent inhibition of other activities. Most proteinases in whole homogenates were insoluble in synthetic enamel fluid. This suggests that they may be tightly bound, directly or indirectly, to matrix proteins or mineral components in situ.

Influence of Fluoride Applications on Some Physicochemical Surface Properties of Synthetic Hydroxyapatite and Human Dental Enamel and Its Consequences for Protein Adsorption

Synthetic hydroxyapatite and human dental enamel (polished and non-polished) were subjected to various fluoride applications, i.e., using solutions of sodium fluoride (NaF), acidulated phosphate fluoride (APF), and stannous fluoride (SnF2). Treatment with APF has a strong influence on the morphology of the apatite. All fluorides, in particular SnF2, make the enamel surfaces more hydrophobic. NaF and APF applications slightly alter the electrokinetic potentials of the surfaces, but SnF2 renders them much more negatively charged. The adsorption of the proteins lysozyme and alpha-lactalbumin on these surfaces can be explained in terms of electrostatic and hydrophobic interactions between the proteins and the sorbent surfaces.

Removal of Synthetic Enamel From Enamel Coated Copper Wires

(1981). Removal of Synthetic Enamel From Enamel Coated Copper Wires. IETE Journal of Research: Vol. 27, No. 9, pp. 320-320.

Infra-Red Stoving for Paint Finishes

The need to raise the temperature of painted motor-cars in order to polmerize the synthetic enamel coating has led to the use of infra-red radiation as the heating agent. Because radiation can be d...