scholarly journals Which Three-Dimensional Printing Technology Can Replace Conventional Manual Method of Manufacturing Oral Appliance? A Preliminary Comparative Study of Physical and Mechanical Properties

2021 ◽  
Vol 12 (1) ◽  
pp. 130
Author(s):  
Hyo-Jin Kim ◽  
Seung-Weon Lim ◽  
Mi-Kyung Lee ◽  
Sung Won Ju ◽  
Suk-Hee Park ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Water Absorption ◽  
Three Dimensional ◽  
Surface Hardness ◽  
Physical And Mechanical Properties ◽  
Color Stability ◽  
Control Group ◽  
Oral Appliances ◽  
Three Dimensional Printing ◽  
Manual Method

Three-dimensional printing technology is widely being adopted in the manufacturing of oral appliances. The purpose of this study was to determine the most suitable method of manufacturing oral appliances by comparing the physical and mechanical properties of various 3D printing methods with the conventional method. Experimental groups consisted of six 3D-printed specimens via FDM, two polyjets, SLS, SLA, and DLP, and the milling methods. The control group consisted of an acrylic resin specimen made by the conventional manual method. The water absorption and solubility, color stability, flexural strength, and surface hardness were tested and statistically analyzed. The FDM, SLS, and DLP methods exhibited comparable water absorption and solubility with the control group, and only the SLA method exhibited significantly higher water solubility than the control group. In terms of the color stability, only the milling method met the requirements of the allowable clinical range. The FDM, SLA, and DLP methods exhibited comparable flexural strength with the control group. The surface hardness of the PJ-2, DLP, and milling methods was acceptable for replacing conventional manual method. Therefore, the most suitable method of manufacturing oral appliances among the experimental groups was the DLP method in terms of its water absorption and solubility, flexural strength, and surface hardness.

Effect of Alumina (Al2O3) to the Properties of Whiteware Porcelain

2020 ◽  
Vol 1010 ◽  
pp. 194-199
Author(s):  
Hamdan Yahya ◽  
Aspaniza Ahmad ◽  
Ismail Ibrahim
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Absorption ◽  
Bulk Density ◽  
Physical And Mechanical Properties ◽  
Porcelain Body ◽  
The Other ◽  
Alumina Content ◽  
Crystalline Phases ◽  
Mullite Phase

The effect of Al2O3 to the properties of whiteware porcelain such as water absorption, bulk density, flexural strength and crystalline phases were studied systematically. The result shows that the addition of alumina at maximum 5 wt.% in porcelain bodies increased the flexural strength of the fired bodies which can reach 55.5 MPa, 30% higher than 0.0% alumina content. However, slight decrease in the other physical and mechanical properties was observed with Al2O3 addition higher than 5 wt.%, which is believed to be due to increased corundum phase compared to mullite phase in porcelain body.

scholarly journals Effect of fly ash on physical and mechanical properties of mortar

2019 ◽  
Vol 17 (6) ◽  
pp. 35
Author(s):  
Vu-An Tran
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Water Absorption ◽  
Thermal Power ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Flow Density ◽  
Control Specimen

This research investigates the physical and mechanical properties of mortar incorporating fly ash (FA), which is by-product of Duyen Hai thermal power plant. Six mixtures of mortar are produced with FA at level of 0%, 10%, 20%, 30%, 40%, and 50% (by volume) as cement replacement and at water-to-binder (W/B) of 0.5. The flow, density, compressive strength, flexural strength, and water absorption tests are made under relevant standard in this study. The results have shown that the higher FA content increases the flow of mortar but significantly decreases the density of mixtures. The water absorption and setting time increases as the samples incorporating FA. Compressive strength of specimen with 10% FA is approximately equal to control specimen at the 91-day age. The flexural strength of specimen ranges from 7.97 MPa to 8.94 MPa at the 91-day age with the best result for samples containing 10% and 20% FA.

Multimaterial printing and characterization for mechanical and surface properties of functionally graded prototype

2019 ◽  
Vol 233 (19-20) ◽  
pp. 6741-6753 ◽  
Author(s):  
Sudhir Kumar ◽  
Rupinder Singh ◽  
TP Singh ◽  
Ajay Batish
Keyword(s):  
Polylactic Acid ◽  
Surface Properties ◽  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Surface Hardness ◽  
Functionally Graded ◽  
Three Dimensional Printing ◽  
Fused Deposition ◽  
Dimensional Printing

In this work, an effort has been made for multimaterial three-dimensional printing of functionally graded prototypes of polylactic acid matrix (tensile specimens as per ASTM D638 type IV) followed by characterization of mechanical and surface properties. The work is an extension of previous reported studies on twin-screw extrusion process for the preparation of multimaterial wires as feedstock filaments in possible three-dimensional printing applications. The results of the study suggest that the highest peak strength (46.28 MPa) and break strength (41.65 MPa) was obtained for multimaterial three-dimensional printed samples at infill density 100%, infill angle 45°, and infill speed of 90 mm/s on commercial open source fused deposition modeling setup. Further surface hardness measurements performed on two extreme surfaces (top surface comprising magnetite (Fe3O4)-reinforced polylactic acid and bottom with polylactic acid without any reinforcement) revealed that the hardness for the bottom layer was more than the hardness for the top layer. From fractured surface analysis (using photomicrographs), it has been observed that the three-dimensional printed samples with low infill density resulted into more void formation due to which the performance while mechanical testing was poor in comparison to samples printed with higher infill density. The results are also supported by rendered images of photomicrographs, which revealed that high roughness value of samples printed with low infill density was also one of the reasons for poor mechanical performance of multimaterial three-dimensional printed functionally graded prototypes.

Influence of active inorganic fillers on the physical and mechanical properties of polyvinyl chloride wood-plastic composites when immersed

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 789-804
Author(s):  
Qiang Jin ◽  
Lin Zhu ◽  
Jiedeerbieke Madiniyeti ◽  
Chunxia He ◽  
Li Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Water Absorption ◽  
Polyvinyl Chloride ◽  
Steel Slag ◽  
Physical And Mechanical Properties ◽  
Control Group ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
Inorganic Fillers

Hydration-active steel slag and slag micropowder were used as inorganic fillers with silane coupling agent (KH550) to prepare wheat straw/polyvinyl chloride wood-plastic composites (WPCs) by extrusion molding. A 35-day immersion and a pre-immersion test were carried out to analyze the influence of steel slag and slag micropowder on the physical and mechanical properties of the WPCs under wet conditions. Results showed the following: (1) KH-550 exhibited a good surface modification effect on the activated steel slag and slag micropowder, (2) an increase in the activated steel slag and slag micropowder content could effectively reduce the percent water absorption of the WPCs by 20% to 25% and the expansion by 20% to 24%, respectively, compared with the control group, but had a limited effect on the tensile strength retention, and (3) pre-immersion could effectively induce the synergistic reinforcement effect of the active fillers, resulting in reaching the saturated water absorption within 20 days. The water absorption and tensile strength were respectively 18% to 25% lower and 1.5% to 3% higher than those of the composites without pre-immersion. The results of this study could provide experimental data and theoretical references for the influence of hydration-active inorganic fillers on WPC properties.

scholarly journals Enhanced Physical and Mechanical Properties of Flake–Shape/Vinyl-ester Nanocomposites Through Surface Modification of Graphene and Glass Flake: A Comparison with Simulated Data

2020 ◽  
Vol 11 (4) ◽  
pp. 11316-11337
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Flexural Strength ◽  
Water Absorption ◽  
Storage Modulus ◽  
Vinyl Ester ◽  
Graphene Nanosheets ◽  
Analytical Data ◽  
Physical And Mechanical Properties ◽  
And Storage

: The main goal of this work was to investigate the effects of silane-modified graphene nanosheets (MGNS) and modified nanoglass flakes (MNGF) on the physical and mechanical properties of vinyl-ester resin (VER) composites. The surface modification was evaluated about these composites' physical and mechanical behavior by techniques such as water absorption, tensile, three-point bending, and dynamic mechanical thermal analysis (DMTA). The analytical data revealed that the silane functionalized nanocomposites improved the interface between the nanosheets and vinyl-ester matrix. It was found that surface modification could significantly improve the dispersion and adhesion of GNS and nanoglass flakes (NGF) compared with those of neat vinyl-ester and unmodified composites. The presence functionalization of NGF and graphene nanosheets (GNS) in vinyl-ester formulation did affect the tensile and flexural strength and modulus, water absorption, and storage modulus. GNS/VER exhibited higher tensile and flexural strength and modulus than the original composite. DMTA results also showed incorporation of NGF and GNS decreased glass transition and increased storage modulus relative to neat composites. Nonetheless, the incorporation of functionalized graphene nanosheets and nano glass flakes represent higher Tg and storage modulus.

scholarly journals The Effect of Denture Cleansers on Color Stability, Water Sorption and Solubility of Stained Denture Base Materials

2018 ◽  
Vol 2 (2) ◽  
pp. 162-173
Author(s):  
Mahabad Saleh ◽  
Salem Salem
Keyword(s):  
Oxalic Acid ◽  
Water Sorption ◽  
Color Change ◽  
Physical And Mechanical Properties ◽  
Color Stability ◽  
Acrylic Resin ◽  
Control Group ◽  
Denture Base ◽  
Base Materials ◽  
Denture Cleansers

Background and Objectives: Denture cleanser is the most widely used method by the patients to maintain clean and healthy dentures but the prolonged use of such cleansers may affect the properties of the denture. The present study was carried out to evaluate the effect of three prepared denture cleansers which were the 4% citric acid, 4% tartaric acid, and 4% oxalic acid in addition to the Protefix a commercially available denture cleansers, on some mechanical and physical properties (color stability, water sorption, and solubility) of acrylic resin (Stellon QC-20) and flexible nylon (Vaplast) denture base materials after immersion in tea solution. Methods: One hundred specimens (100) were prepared in two equal major groups: acrylic resin and Valplast. For each test of the physical and mechanical properties, 50 specimens were prepared, 25 from acrylic resin and 25 from Valplast. Later on, divided into five groups, one group used as a control and immersed in distilled water, and remaining 4 groups used as test groups; by immersing in one of the denture cleansers after staining in tea solutions for 10 days. The effect of denture cleansers on the properties was studied and compared with the control group. Results: Visual examination method showed no color changes for acrylic and slight color change for valplast specimens. Valplast specimens showed higher water sorption and solubility than acrylic. Conclusions: The findings showed that the 4 denture cleansers were equally effective, and did not cause significant alteration in the tested properties. Except acrylic specimens immersed in oxalic acid showed less color stability.

scholarly journals Alkali-Activated Mortars with Recycled Fines and Hemp as a Sand

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4580
Author(s):  
Edyta Pawluczuk ◽  
Katarzyna Kalinowska-Wichrowska ◽  
Mahfooz Soomro
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Water Absorption ◽  
Physical And Mechanical Properties ◽  
Hydrated Lime ◽  
Optical Microscope ◽  
Volume Density ◽  
Waste Materials ◽  
Natural Sand ◽  
Alkali Activated

Nowadays, effective and eco-friendly ways of using waste materials that could replace natural resources (for example, sand) in the production of concrete composites are highly sought. The article presents the results of research on geopolymer composites produced from two types of waste materials—hemp and fine fractions recovered from recycled cement concrete, which were both used as a replacement for standard sand. A total of two research experiments were conducted. In the first experiment, geopolymer mortars were made using the standard sand, which was substituted with recycled fines, from 0% to 30% by weight. In the second study, geopolymers containing organic filler were designed, where the variables were (i) the amount of hemp and the percent of sand by volume (0%, 2.5%, and 5%) and(ii) the amount of hydrated lime and the percent of fly ash (by weight) (0%, 2%, and 4%) that were prepared. In both cases, the basic properties of the prepared composites were determined, including their flexural strength, compressive strength, volume density in a dry and saturated state, and water absorption by weight. Observations of the microstructure of the geopolymers using an electron and optical microscope were also conducted. The test results show that both materials (hemp and recycled fines) and the appropriate selection of the proportions of mortar components and can produce composites with better physical and mechanical properties compared to mortars made of only natural sand. The detailed results show that recycled fines (RF) can be a valuable substitute for natural sand. The presence of 30% recycled fines (by weight) as a replacement for natural sand in the alkali-activated mortar increased its compressive strength by 26% and its flexural strength by 9% compared to control composites (compared to composites made entirely of sand without its alternatives). The good dispersion of both materials in the geopolymer matrix probably contributed to filling of the pores and reducing the water absorption of the composites. The use of hemp as a sand substitute generally caused a decrease in the strength properties of geopolymer mortar, but satisfactory results were achieved with the substitution of 2.5% hemp (by volume) as a replacement for standard sand (40 MPa for compressive strength, and 6.3MPa for flexural strength). Both of these waste materials could be used as a substitute for natural sand and are examples of an eco-friendly and sustainable substitution to save natural, non-renewable resources.

scholarly journals Investigating the Mechanical Properties of ZrO2-Impregnated PMMA Nanocomposite for Denture-Based Applications

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1344 ◽  
Author(s):  
Saleh Zidan ◽  
Nikolaos Silikas ◽  
Abdulaziz Alhotan ◽  
Julfikar Haider ◽  
Julian Yates
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Impact Strength ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Surface Hardness ◽  
Bending Test ◽  
Zro2 Nanoparticles ◽  
Control Group ◽  
The Mean

Acrylic resin PMMA (poly-methyl methacrylate) is used in the manufacture of denture bases but its mechanical properties can be deficient in this role. This study investigated the mechanical properties (flexural strength, fracture toughness, impact strength, and hardness) and fracture behavior of a commercial, high impact (HI), heat-cured denture base acrylic resin impregnated with different concentrations of yttria-stabilized zirconia (ZrO2) nanoparticles. Six groups were prepared having different wt% concentrations of ZrO2 nanoparticles: 0% (control), 1.5%, 3%, 5%, 7%, and 10%, respectively. Flexural strength and flexural modulus were measured using a three-point bending test and surface hardness was evaluated using the Vickers hardness test. Fracture toughness and impact strength were evaluated using a single edge bending test and Charpy impact instrument. The fractured surfaces of impact test specimens were also observed using a scanning electron microscope (SEM). Statistical analyses were conducted on the data obtained from the experiments. The mean flexural strength of ZrO2/PMMA nanocomposites (84 ± 6 MPa) at 3 wt% zirconia was significantly greater than that of the control group (72 ± 9 MPa) (p < 0.05). The mean flexural modulus was also significantly improved with different concentrations of zirconia when compared to the control group, with 5 wt% zirconia demonstrating the largest (23%) improvement. The mean fracture toughness increased in the group containing 5 wt% zirconia compared to the control group, but it was not significant. However, the median impact strength for all groups containing zirconia generally decreased when compared to the control group. Vickers hardness (HV) values significantly increased with an increase in ZrO2 content, with the highest values obtained at 10 wt%, at 0 day (22.9 HV0.05) in dry conditions when compared to the values obtained after immersing the specimens for seven days (18.4 HV0.05) and 45 days (16.3 HV0.05) in distilled water. Incorporation of ZrO2 nanoparticles into high impact PMMA resin significantly improved flexural strength, flexural modulus, fracture toughness and surface hardness, with an optimum concentration of 3–5 wt% zirconia. However, the impact strength of the nanocomposites decreased, apart from the 5 wt% zirconia group.

Application Using Sugar Sediment to Enhance Mechanical Properties of Autoclaved Aerated Concrete

2013 ◽  
Vol 459 ◽  
pp. 664-668
Author(s):  
Atthakorn Thongtha ◽  
Somchai Maneewan ◽  
Chantana Punlek ◽  
Yothin Ungkoon
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Water Absorption ◽  
Open Porosity ◽  
Physical And Mechanical Properties ◽  
Fine Sand ◽  
Average Density ◽  
Quality Class ◽  
Sediment Content

The effect of fine sand replacement by the sugar sediment (0, 10, 15, 20, 25, 30, 35, 40, 45 and 50 weight %) on the physical and mechanical properties was studied in this work. The physical and mechanical properties of AAC with various contents of sugar sediment were focused on the density, the humidity, the water absorption, the open porosity volume, the compressive strength and the flexural strength. The average density, humidity, water absorption, volume of open porosity, compressive strength and flexural strength of all compositions had the value in the range of 0.57-0.61 g/cm3, 23.0-26.7 %, 0.38-0.40 g/cm3, 259-287 cm3, 4.4-5.9 N/mm2and 1.03-1.82 N/mm2, respectively. The maximum compressive strength and flexural strength were found from the AAC sample with the sugar sediment content of 30%, which were 5.9 N/mm2and 18.14 N/mm2. Moreover, these samples also exhibited the density (0.60 g/cm3), the humidity (23.6%), the water absorption (0.39 g/cm3) and the volume of open porosity (272 cm3) were claimed in quality class of 4. The specimens of AAC with the sugar sediment content of 0-40% were claimed in quality class of 4, which based on the Thai Industrial Standard 1505-1998.

Evaluation of Color Changes of Dental Luting Materials in Food Colorant Solutions

2017 ◽  
Vol 40 (9) ◽  
pp. 503-509 ◽  
Author(s):  
Canan Akay ◽  
Merve Ç. Taniş
Keyword(s):  
Water Absorption ◽  
Color Stability ◽  
Resin Cement ◽  
The Self ◽  
Control Group ◽  
Sunset Yellow ◽  
Adhesive Resin ◽  
Food Colorant ◽  
Adhesive Resin Cement ◽  
Luting Material

Background The purpose of this study was to compare the color stability and water absorption of 3 commercially available resin cements in vitro by storing them in 0.15% erythrosine, dark brown and sunset yellow for 30 days. Methods 2 self-adhesive resin cements and 1 dual/light curing, resin-based dental luting material were evaluated (total 120 samples). The CIE L, a, b of 10 mm diameter-2.0 mm height disk shaped samples was measured using a spectrophotometer for color stability on a white background, 10 mm diameter-1.0 mm height disk shaped samples were measured for water absorption before and after storage in food colorant solutions. Results The self-adhesive resin cement-sunset yellow group caused the most severe discoloration (27.89 ± 3.64) that is clinically unacceptable. The lowest discoloration was seen in the self-adhesive resin cement control group (3.35 ± 1.13). The highest water absorption was observed in the self-adhesive resin cement-dark brown group (2.41 ± 0.60) and the lowest water absorption in the dental luting material-control group (0.65 ± 0.17). Conclusions: Storage food colorant solutions affected the color stability and water absorption of different resin cement materials.

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