Papers by Keyword: Enamel

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Authors: Robert L. Karlinsey, Allen C. Mackey, Emily R. Walker, Trenton J. Walker, Christabel X. Fowler
Abstract: The inability to sufficiently prevent and/or repair chemically-etched dental enamel serves as one example that underlines the importance and need for the development of innovative biomaterials for therapeutic applications. In this work we explored the seeding capability of 225 ppm and 1100 ppm fluoride with and without a novel β-tricalcium phosphate-silica-urea (TCP-Si-Ur) biomaterial (concentrations of 20, 40, 80, and 200 ppm) to mineralize into acid-etched bovine enamel. The nature of the mineralization was evaluated by measuring the fluoride and phosphate uptake into the eroded enamel, as well as the orthophosphate microstructure using infrared (IR) spectroscopy. These enamel fluoride uptake and IR experiments revealed a fluoride dose response exists for eroded enamel treated with 225 and 1100 ppm F. The inclusion of 20, 40, and 80 ppm TCP-Si-Ur with 225 ppm F was similar to 225 ppm F alone and did not produce a fluoride uptake dose response; however, 200 ppm TCP-Si-Ur combined with 1100 ppm F improved raw fluoride uptake relative to 1100 ppm F. Furthermore, we found the combination of either 225 ppm or 1100 ppm fluoride plus TCP-Si-Ur at different loading levels leads to unique and significant mineral integration into the PO4 enamel network, including the formation of P-F bonds. The observations reported herein demonstrate the combination of fluoride plus a novel TCP-Si-Ur biomaterial produces synergistic mineralization and bears significantly on eroded enamel microstructure.
Authors: Fu Zhai Cui, Zhen Jiang Chen, Jun Ge
Abstract: In this paper, an overview on nanoindentation and its combination with AFM is presented with regard to current instrument technology and applications on dental and bony tissues. Nanoindentation has been a widely used technique to determine the mechanical properties such as nanohardness and Young’s modulus for nanostructured materials. Especially, atomic force microscopy (AFM) combined with nanoindentation, with the pit positions controlled accurately, become a powerful technique used to measure mechanical properties of materials on the nanoscale, and has been applied to the study of biological hard tissues, such as bone and tooth. Examples will be shown that significantly different nanohardness and modulus in the isolated domains within single enamel, the prisms, interprisms, the surrounding sheaths and the different parts of skeletal bone, could been distinguished, while such information was unable to be obtained by traditional methods of mechanical measurements.
Authors: Li Yun Chen, Xiao Ping Liao, Wei Zhong Jiang, Jia Yi Ye, Hui Le Jin, Ai Li Liu
Abstract: nanosize TiO2/SiO2 thin films were deposited by sol-gel dip-coating method on enamel substrates. Crystal structure, micro-structure, hydrophilic property, gloss property was investigated by X-ray diffract meter, scanning electron microscope, CCD camera, enamel gloss meter. The results show that the hydrophilic property of the enamel was greatly increased by heating the enamel with coating TiO2/SiO2 film; the gloss property of the enamel surface greatly increased after the enamel coated with TiO2/SiO2 film. The main crystals in TiO2/SiO2 film on the enamel were anatase when the baking temperature was below the 700°C.
Authors: S. H. Jeong, S.O. Jang, Kyoung Nam Kim, H.K. Kwon, Yong Duk Park, B.I. Kim
Abstract: Hydroxyapatite is the main component of enamel that gives the tooth a bright white appearance and eliminates the diffused reflection of light by filling up the fine pores of the tooth surface. Accordingly, remineralization of the teeth can be expected to some extent if hydroxyapatite is used to treat an incipient caries lesion (early white spot lesion). In addition, the remineralization effect will be increased if the particle size of hydroxyapatite can be reduced to less than that of the micron-size in existing toothpaste preparations. The aim of this in vitro study was to evaluate the effect of nano-hydroxyapatite toothpaste, which was produced by nano-technology, on the remineralization of human enamel. A tooth specimen, on which artificial incipient caries had been induced, was immersed into two toothpaste slurries for remineralization. One contains nano-sized hydroxyapatite and fluoride, and the other contains nano-sized hydroxyapatite excluding fluoride. In order to evaluate the remineralization effect, the Vickers Hardness Number & SEM image of the enamel surface was evaluated at each step. There were significant differences in VHN values between those obtained before and after the remineralization steps. The results showed that the remineralization effect increased with increasing immersing time (P<0.05). However, there were no significant differences in VHN values between the two groups (P>0.05). SEM also demonstrated differences the in micro surface at each step. In conclusion, a toothpaste containing nano-sized hydroxyapatite has the potential to remineralize an incipient caries lesion. In addition, the addition of fluoride had no synergistic effect on remineralization.
Authors: Pattamaporn Prapitpongwanich
Abstract: The project aims to produce quality enamel colors from locally available materials in order to reduce costs. In the course of the research, information is collected on imported enamel colors and a study is carried out on chemical compositions and quality of the colors. At the same time, there is a study on local materials which can potentially be used to produce enamel colors, starting from basic colors such as red, blue and green. The study has found that the imported enamel colors qualify as lead glass because it contains 23-28% of lead. The study has also found that red enamel (transparent) blue enamel (transparent), blue enamel (opaque), green enamel (transparent), and green enamel (opaque) have similar level of density and hardness. Red enamel (opaque) has lower level of density and hardness due to its porosity which can be observed with naked eyes. The COE level is similar for all of the tested colors because their chemical compositions are similar. The study produces quality blue and green enamel at much lower cost. Colors of the enamel are achieved by adding different metal oxide. The color blue (translucent and opaque) is from adding cobalt (Co). Chromium (Cr), manganese (Mn), iron (Fe), cobalt and copper (Cu) together produces translucent dark green, while chromium and copper (without cobalt) produces opaque as lighter green. However, it has not been able to produce red enamel yet but has requested for samples from another research project “Developing New Technology to Produce Jewelry from Synthesized Red Crystal” for further study.Keywords: Enamel; Jewelry; Glass; Local Raw Materials
Authors: Kun Tian, Min Peng, Ping Wu, Chu Hang Liao, Fa Yin Huang
Abstract: Based on the basic theory of molecular recognition, we designed an organic molecules model that spontaneously form three-dimensional fibrillar scaffolds to induce the crystallization of hydroxyapatite to synthesized enamel-like calcium phosphate/hydroxyapatite under a controllable way in vitro. Cross-linking of collagen on the dentin surface and silk fibroin with N,N-(3-dimethylaminopropyl)-N'-ethyl-carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) was optimized by varying the NHS/EDC molar ratio at constant EDC concentration. CaCl2 and Na3PO4-12H2O solution was added with Ca: P odd as 1.67:1 after conjugated. The results showed that the dentinal tubule were blocked by neonatal hydroxyapatite layer which has a continuous structure of columns crystal with size of 10-40nm. Furthermore, there were column crystal with parallel direction inside, similar to the crystal array in the top of enamel rod. The results suggest that silk protein monolayer may be useful in the modulation of mineral behavior during in situ dental tissue engineering.
Authors: Yasin Genc, Faik N. Oktar, E.Z. Erkmen, G. Göller, D. Toykan, H. Haybat
Authors: D.Y. Zheng, Yu Ming Xiong, Sheng Long Zhu, Fu Hui Wang, Wei Tao Wu
Abstract: The specimens of O-phase Ti-22Al-25Nb (at%) intermetallics coated with silica-based enamel received mass gains of about 1 mg/cm2, after 300 h of oxidation or hot corrosion at 800 °C. These rates were much faster than the growth rates of silica films at the same temperature. To understand this phenomena, the specimens were analyzed using SEM, XRD, EPMA and TEM. An oxide layer with thickness of several μm was observed at the enamel/substrate interface of the coated specimens after either oxidation or hot corrosion. XRD and TEM analysis revealed the newly formed oxide layer was composed of α-Al2O3, Al2SiO5, Al2TiO5, rutile-TiO2 and NbO2. It was shown by EPMA profiling that an Al-depleted zone was located just beneath the oxides. It was proposed that the solid reactions between the enamel coating and the O-phase Ti-Al-Nb played important roles for the oxidation and hot corrosion behavior of the coated specimens.
Authors: Rui Zhang, Qian Qian Lin, Fan Bieke Wu, Zhen Guo Wang, Bin Liu
Abstract: Objective: To test and contrastive analysis the crystal structure and mechanical characteristics of enamel and dentin of primary and permanent teeth by XRD and contact angle meter, provide information and experimental data for bionics and designs of dental materials. Methods: Teeth were randomly divided into four groups, including permanent teeth enamel group, permanent teeth dentin group, primary teeth enamel group, and primary teeth primary teeth. The crystal structure and mechanical characteristics of teeth were tested by XRD and contact angle meter. The results were analyzed with one-way ANOVA. Results: The crystalline and grain size of enamel were significantly larger than dentin’s. The crystalline and grain size of enamel and dentin of permanent teeth were also larger than primary teeth. Conclusions: The XRD and contact angle of primary and permanent teeth are closely related to their structures, Dental filling material to give full consideration to their different property.
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