Tribological changes of tooth enamel-mullite/3Y-TZP couple in artificial saliva

2021 ◽  
Author(s):  
Yanqi Huang ◽  
Zhuan Li ◽  
Peng-fei Liu ◽  
Yan-meng Cheng ◽  
Wen-jie Li ◽  
...  
Keyword(s):  
Tooth Enamel ◽  
Artificial Saliva ◽  
Composite Ceramic ◽  
Fatigue Wear ◽  
Friction Process ◽  
Gel Casting ◽  
Potential Applications ◽  
Acute Cytotoxicity ◽  
Friction Method

Abstract In-situ mullite toughened 3Y-TZP composite ceramic (mullite/3Y-TZP) with excellent mechanical properties was fabricated by gel-casting. The cytotoxicity of mullite/3Y-TZP was determined by both extract and direct contact methods, and the results indicated that mullite/3Y-TZP had no acute cytotoxicity. Furthermore, the tribological properties of the tooth enamel sliding against mullite/3Y-TZP in artificial saliva were investigated by using the pin-on-plate friction method. The friction coefficient (μ) between the two friction samples was about 0.464 with a stable friction process, and both of them showed slight wear. Analysis of the wear surface and debris demonstrated that the tooth enamel mainly suffered from fatigue wear accompanied by mild adhesive wear, while mullite/3Y-TZP showed slight abrasive wear. This result indicated that mullite/3Y-TZP had good wear resistance and showed potential applications in dental material.

scholarly journals Tribological changes of tooth enamel-mullite/3Y-TZP couple in artificial saliva

2020 ◽  
Author(s):  
Yanqi Huang ◽  
Zhuan Li ◽  
Peng-fei Liu ◽  
Yan-meng Cheng ◽  
Wen-jie Li ◽  
...  
Keyword(s):  
Tooth Enamel ◽  
Artificial Saliva ◽  
Composite Ceramic ◽  
Fatigue Wear ◽  
Gel Casting ◽  
Potential Applications ◽  
Acute Cytotoxicity ◽  
Disk Friction ◽  
Friction Method ◽  
Pin On Disk

Abstract In-situ mullite toughened 3Y-TZP composite ceramic (mullite/3Y-TZP) with excellent mechanical properties was fabricated by gel-casting. The cytotoxicity of mullite/3Y-TZP was determined by both extract and direct contact methods, and the results indicated that mullite/3Y-TZP had no acute cytotoxicity. Furthermore, the tribological properties of the tooth enamel sliding against mullite/3Y-TZP in artificial saliva were investigated by using the pin-on-disk friction method. The friction coefficient (µ) between the two friction samples was about 0.464 with a stable friction process, and both of them showed slight wear. Analysis of the wear surface and debris demonstrated that the tooth enamel mainly suffered from fatigue wear accompanied by mild adhesive wear, while mullite/3Y-TZP showed slight abrasive wear. This result indicated that mullite/3Y-TZP had good wear resistance and showed potential applications in dental material.

Effect of Solid Loading on Properties of All-Ceramic Crown by Gel-Casting Technique

2013 ◽  
Vol 833 ◽  
pp. 169-172
Author(s):  
Peng Zhang ◽  
Hong Yu Guan
Keyword(s):  
Bending Strength ◽  
Ceramic Powder ◽  
Composite Ceramic ◽  
Solid Content ◽  
Solid Loading ◽  
Casting Technique ◽  
Gel Casting ◽  
The Mean ◽  
Ceramic Crown

To compare the influence of porosity on bending strength, density, viscosity of slurry of dental zirconia-toughened alumina(Ce-TZP/A) ceramic by gel-casting technique. Ce-TZP/A composite ceramic powder was made from a Al2O3 of micron grade and 3Ce-ZrO2 of nanometer grade, with sintering additives of MgO and TiO2. The slurries of 5(v/v), 52%, 54%, 56% ,58% and 60% were prepared separately, and sintered at 1200°C after in situ molding using gel-casting. The properties such as bending strength, density, viscosity of slurry of specimens were measure and compared. Slurry was prepared with optimum solid content, and applied to form dental CeTZP/A basal crown on the plaster die. The marginal fitness of crowns was observed after sintered. The mean viscosity of slurry (PaS) were: 0.27±0.05, 0.31±0.1, 0.33±0.09, 0.96±0.12, 1.01±0.07, 1.21±0.02. The effect of solid loading (P=0.05) were significant. The mean bending strength (MPa) were: 43.15±0.8, 47.9±1.5, 50.09±1.7, 58.12±1.9, 39.17±1.6, 35.08±1.2. The mean toughness (MPa m^1/2) were: 17.6±0.8, 16.9±0.6, 16.1±0.5, 17.8±0.9, 18.6±0.8, 20.5±0.2. The mean density (g/cm) were: 5.32±0.9, 5.43±0.8, 6.13±0.5, 6.01±0.5, 5.13±0.3, 5.05±0.4. The specimen formed from slurry of 52(v/v) had better properties than that of others solid loading after sintered at 1150º. With the solid loading increased, the viscosity of slurry has a significantly improved.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

scholarly journals Influence of protein (human galectin-3) design on aspects of lectin activity

2020 ◽  
Vol 154 (2) ◽  
pp. 135-153 ◽  
Author(s):  
Gabriel García Caballero ◽  
Donella Beckwith ◽  
Nadezhda V. Shilova ◽  
Adele Gabba ◽  
Tanja J. Kutzner ◽  
...  
Keyword(s):  
Protein Design ◽  
Full Range ◽  
Biological Information ◽  
The Novel ◽  
Modular Assembly ◽  
Binding Partners ◽  
Galectin 3 ◽  
Potential Applications ◽  
Similar Affinity

Abstract The concept of biomedical significance of the functional pairing between tissue lectins and their glycoconjugate counterreceptors has reached the mainstream of research on the flow of biological information. A major challenge now is to identify the principles of structure–activity relationships that underlie specificity of recognition and the ensuing post-binding processes. Toward this end, we focus on a distinct feature on the side of the lectin, i.e. its architecture to present the carbohydrate recognition domain (CRD). Working with a multifunctional human lectin, i.e. galectin-3, as model, its CRD is used in protein engineering to build variants with different modular assembly. Hereby, it becomes possible to compare activity features of the natural design, i.e. CRD attached to an N-terminal tail, with those of homo- and heterodimers and the tail-free protein. Thermodynamics of binding disaccharides proved full activity of all proteins at very similar affinity. The following glycan array testing revealed maintained preferential contact formation with N-acetyllactosamine oligomers and histo-blood group ABH epitopes irrespective of variant design. The study of carbohydrate-inhibitable binding of the test panel disclosed up to qualitative cell-type-dependent differences in sections of fixed murine epididymis and especially jejunum. By probing topological aspects of binding, the susceptibility to inhibition by a tetravalent glycocluster was markedly different for the wild-type vs the homodimeric variant proteins. The results teach the salient lesson that protein design matters: the type of CRD presentation can have a profound bearing on whether basically suited oligosaccharides, which for example tested positively in an array, will become binding partners in situ. When lectin-glycoconjugate aggregates (lattices) are formed, their structural organization will depend on this parameter. Further testing (ga)lectin variants will thus be instrumental (i) to define the full range of impact of altering protein assembly and (ii) to explain why certain types of design have been favored during the course of evolution, besides opening biomedical perspectives for potential applications of the novel galectin forms.

scholarly journals Variability and improvement of optical and antimicrobial performances for CQDs/mesoporous SiO2/Ag NPs composites via in situ synthesis

2021 ◽  
Vol 10 (1) ◽  
pp. 403-411
Author(s):  
Youliang Cheng ◽  
Mingjie Wang ◽  
Changqing Fang ◽  
Ying Wei ◽  
Jing Chen ◽  
...  
Keyword(s):  
Uv Light ◽  
Carbon Quantum Dots ◽  
Diffusion Method ◽  
Ag Nps ◽  
Uniform Size ◽  
High Antibacterial Activity ◽  
Fluorescent Materials ◽  
Potential Applications ◽  
Mesoporous Sio2

Abstract To change the optical properties and improve the antibacterial performances of carbon quantum dots (CQDs) and Ag NPs, mesoporous SiO2 spheres were combined with them to form the composites. In this paper, CQDs with a uniform size of about 3.74 nm were synthesized using glucose as carbon source. Then, CQDs/mesoporous SiO2/Ag NPs composites were obtained in situ under UV light irradiating by using mesoporous SiO2 and Ag NO3 as the carrier and silver resource, respectively. The diameter of CQDs/mesoporous SiO2/Ag NPs particles was in the range of 200–250 nm. With the increase in irradiating time, the red-shift in the UV-Vis spectrum for as-prepared CQDs/mesoporous SiO2/Ag NPs composites was found, and the adsorption peak was widened. In addition, the composites showed a high antibacterial activity against Staphylococcus aureus and Escherichia coli via disc diffusion method. These results indicated that inhibition circles for Ag NPs/mesoporous SiO2/CQDs and mesoporous SiO2/Ag NPs were similar in diameter. Furthermore, the two composites had a better bactericidal performance compared with other particles. Therefore, as-prepared CQDs/mesoporous SiO2/Ag NPs composites in this paper have great potential applications for fluorescent materials and antibacterial materials.

An in sita Model for Simultaneous Assessment of Inhibition of Demineralization and Enhancement of Remineralization

1992 ◽  
Vol 71 (3_suppl) ◽  
pp. 804-810 ◽  
Author(s):  
J.D.B. Featherstone ◽  
D.T. Zero
Keyword(s):  
Tooth Enamel ◽  
Dental Health ◽  
Oral Care ◽  
Protective Effects ◽  
Cross Sectional ◽  
Food Component ◽  
Whole Saliva ◽  
Salivary Function

In situ models to assess the ability of oral care products or food components to enhance remineralization and/or inhibit demineralization of tooth enamel or roots must be very carefully designed to minimize the confounding effects of the many variables involved. Controlling these variables as closely as possible is essential if meaningful answers are to be obtained from the models. We have developed an in situ model which combines the experience of several groups. Detailed screening of subjects is essential. Selection criteria should include good general health, good dental health, mandibular partial denture, at least eight natural teeth, no active caries lesions, known fluoride history, normal salivary function, and no medications that affect salivary function. Each subject carries a sound enamel slab and an enamel slab with a pre-formed caries-like lesion (demineralized in vitro) in his/her denture on each side of the mouth for test periods of two or four weeks. The demineralization challenge is controlled by extra-oral immersion of the appliances in sucrose daily. Daily product exposure or daily food component exposure is used as desired. Compliance indicators and a diet diary are included. Whole saliva flow rate (unstimulated), plaque acidogenicity, and salivary fluoride are monitored during the test periods. At the end of the test period, the test slabs are assessed for mineral change, after being sectioned, by means of cross-sectional microhardness or microradiography. The mineral loss or gain (ΔM, μm × vol%), compared with adjacent control sections retained in the lab, is calculated as change in ΔZ (μm × vol%), namely, ΔM = ΔZTEST - ΔZ.CONTROL. In this model, demineralization occurs in sound enamel and in the pre-formed lesions in the absence of fluoride or other protective agents. The model has the potential to be able to differentiate among fluoride delivery systems and to assess the caries-protective effects of agents other than fluoride by use of small groups of subjects.

Hydroxyapatite-anchored dendrimer for in situ remineralization of human tooth enamel

Biomaterials ◽  
2013 ◽  
Vol 34 (21) ◽  
pp. 5036-5047 ◽  
Author(s):  
Duo Wu ◽  
Jiaojiao Yang ◽  
Jiyao Li ◽  
Liang Chen ◽  
Bei Tang ◽  
...  
Keyword(s):  
Tooth Enamel ◽  
Human Tooth ◽  
Human Tooth Enamel
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