Mechanical Strength Improvement of Apatite Cement Using Hydroxyapatite/Collagen Nanocomposite

2016 ◽  
Vol 720 ◽  
pp. 167-172 ◽  
Author(s):  
Arief Cahyanto ◽  
Kanji Tsuru ◽  
Kunio Ishikawa ◽  
Masanori Kikuchi
Keyword(s):  
Fracture Surface ◽  
Mechanical Strength ◽  
Setting Time ◽  
Control Group ◽  
Scanning Electron Micrographs ◽  
Setting Times ◽  
Apatite Cement ◽  
Xrd Patterns ◽  
Mechanical Strengths ◽  
Scanning Electron

The combination of tetracalcium phosphate (TTCP; Ca4(PO4)2O) and dicalcium phosphate anhydrous (DCPA; CaHPO4) which are known as one system of apatite cements already used in the medical and dental application. In spite of several advantages of apatite cements, such as self-setting ability and biocompatibility, their mechanical strengths are still low. The aim of this study is to improve the mechanical strength of the TTCP-DCPA apatite cement using the hydroxyapatite/collagen nanocomposite (HAp/Col). The apatite cement powder was prepared using an equimolar TTCP and DCPA with addition of 10% and 20% of the HAp/Col. That without the HAp/Col was used as a control group. Each group was mixed with 1 mol/L Na1.8H1.2PO4 aqueous solution at powder/liquid ratio of 0.5 and hardened at 37°C and 100 % of relative humidity for 24 hours. A setting time of the cement was evaluated using Vicat needle according to ISO 1566 for dental zinc phosphate cements. Morphology of the cements set were observed by the scanning electron microscopy (SEM), and crystalline phases were identified by the powder X-Ray diffractometry (XRD). The mechanical strength of the cement set was evaluated by the diametral tensile strength (DTS). The setting times of cements were the shortest for the cement with HAp/Col and the longest for the control. XRD patterns of the cement at 24 hours after mixing revealed that all cements changed into apatite from the mixture of TTCP and DCPA. The DTSs of cements were the highest for the cement with 20% HAp/Col and the lowest for the control with significant differences between the cement with 20 % HAp/Col and respective other two cements. The scanning electron micrographs of the surface and fracture surface of the cements suggested that the cement with HAp/Col showed denser structure in comparison to the control and the HAp/Col fibers and/or sheets covered the fracture surface. The HAp/Col would act as reinforcement fibers as well as an adhesive of apatite granules formed by the reaction between TTCP and DCPA. The setting time and mechanical strength of apatite cement was statistically significant improved by adding 20% HAp/Col.

scholarly journals Influence of the Treatment Temperature on the Microstructure and Hydration Behavior of Thermoactivated Recycled Cement

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3937
Author(s):  
Sofia Real ◽  
Ana Carriço ◽  
José Alexandre Bogas ◽  
Mafalda Guedes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Strength ◽  
Water Demand ◽  
Isothermal Calorimetry ◽  
Setting Time ◽  
Treatment Temperature ◽  
Diffraction Field ◽  
Resonance Spectroscopy ◽  
Scanning Electron

This paper intends to contribute to a better knowledge of the production and rehydration of thermoactivated recycled cement and its incorporation in cement-based materials. To this end, the influence of the treatment temperature on the properties of recycled cements and recycled cement pastes was assessed by means of a wide array of tests. Anhydrous recycled cement as well as the resulting pastes were characterized through density and particle size, water demand and setting time, thermogravimetry, X-ray diffraction, field emission gun scanning electron microscopy, isothermal calorimetry, 29Si nuclear magnetic resonance spectroscopy, flowability, mechanical strength, mercury intrusion porosimetry and scanning electron microscopy. The treatment temperature had a significant influence on the dehydration and hydration of recycled cement, essentially resulting in the formation of C2S polymorphs of varying reactivity, which led to pastes of different fresh and hardened behaviors. The high water demand and the pre-hydration of recycled cement resulted in high setting times and low compressive strengths. The highest mechanical strength was obtained for a treatment temperature of 650 °C.

scholarly journals Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
El-Sayed Negim ◽  
Latipa Kozhamzharova ◽  
Yeligbayeva Gulzhakhan ◽  
Jamal Khatib ◽  
Lyazzat Bekbayeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
High Volume ◽  
Physicomechanical Properties ◽  
Partial Replacement ◽  
Setting Times ◽  
High Volume Fly Ash ◽  
Scanning Electron

This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

Effect of Added Tricalcium Phosphate on Basic Properties of Apatite Cement

2007 ◽  
Vol 361-363 ◽  
pp. 339-342
Author(s):  
Akari Takeuchi ◽  
Akinari Nakagawa ◽  
Shigeki Matsuya ◽  
Ishikawa Kunio
Keyword(s):  
Crystal Growth ◽  
Mechanical Strength ◽  
Tricalcium Phosphate ◽  
Setting Time ◽  
Tetracalcium Phosphate ◽  
Initial Setting Time ◽  
Setting Reaction ◽  
Phosphate Ions ◽  
Initial Setting ◽  
Apatite Cement

Effect of added α-tricalcium phosphate (α-TCP) and β-TCP was investigated to understand the setting reaction of apatite cement consisting of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA). Addition of TCP delayed the initial setting time because TCP was not involved in the initial setting reaction and resulted in the decreased initial mechanical strength. After the initial setting of the cement due to the conversion of TTCP and DCPA into apatite, α-TCP dissolved to supply calcium and phosphate ions and they were consumed for crystal growth of apatite. Therefore, mechanical strength of the apatite cement containing α-TCP was increased. In contrast, added β-TCP showed no reactivity in the cement and thus result in the decreased mechanical strength.

scholarly journals Effect of Implantoplasty on Fatigue Performance and Surface Roughness of Narrow Diameter Dental Implants

2021 ◽  
Author(s):  
Octavi Camps-Font ◽  
Jorge Toledano-Serrabona ◽  
Ana Juiz-Camps ◽  
Rui Figueiredo ◽  
Cosme Gay-Escoda ◽  
...  
Keyword(s):  
Dental Implants ◽  
Visual Inspection ◽  
Bacterial Colonization ◽  
Testing Machine ◽  
Optical Microscope ◽  
Control Group ◽  
Scanning Electron Micrographs ◽  
Number Of Cycles ◽  
Type Of Failure ◽  
Scanning Electron

Abstract Implantoplasty (IP) is used in dental implants with peri-implantitis and aims to remove threads and polish rough surfaces in order to prevent bacterial colonization. As a result of this procedure, implant strength might be compromised. We tested 20 tapered screw-shaped Ti6Al4V dental implants with a simulated bone loss of 50%. Ten implants underwent IP and 10 served as controls. Surface topography (Sa, Sz, Ssk and Sdr) was analyzed with a confocal optical microscope. Subsequently, cyclic loads were applied with a servo-hydraulic mechanical testing machine (5x106 cycles at 15 Hz, between the maximal compression force - 529N in the IP group and 735N in the control group - and 10% of that force). We recorded the number of cycles until failure and the type of failure. Implant failure was analyzed by visual inspection and scanning electron microscopy. Implantoplasty reduced the median Sa from 1.76 (IQR=0.11) to 0.49 (IQR=0.16). The fatigue limits of the control and implantoplasty groups were 551 N and 529 N, respectively. The scanning electron micrographs showed fatigue striations indicating fatigue failure. The infinite life range of the dental implants evaluated was largely above the threshold of usual chewing forces. Implantoplasty seems to render a fairly smooth surface and has a limited impact upon fatigue resistance.

Setting Time, Handling Property and Mechanical Strength Evaluation of SCPC50 and Apatite Cement Mixture in Various Combinations

2019 ◽  
Vol 829 ◽  
pp. 40-45
Author(s):  
Ira Artilia ◽  
Myrna Nurlatifah Zakaria ◽  
Arief Cahyanto
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Bone Cells ◽  
Setting Time ◽  
Ideal Self ◽  
Proliferation And Differentiation ◽  
Apatite Cement ◽  
Physical Shape ◽  
Cement Mixture ◽  
Diametral Tensile Strength

Apatite cement is ideal self-setting cement for bone substitute material, however its use is limited only to areas that receive minimum load bearing because mechanical strength of apatite cement is low. Silica-calcium phosphate nanocomposite (SCPC50) is material having good mechanical strength and has an important role in bone remodeling (bone metabolism), mineralization, synthesis of cartilage, collagen production, proliferation and differentiation of bone cells. However, the unsetting and granule’s physical shape of SCPC50 limits the application. The purpose of this study is to determine the effect of various mixtures of SCPC50 and apatite cement to manipulative index (setting time and handling property), and mechanical properties. The experimental results show that the setting time of apatite cement mixture with 5% and 10% SCPC50 was 40% higher (p<0.05). The mechanical strength evaluated by Diametral Tensile Strength showed that the addition of both 5% silica and 10% SCPC50 composition to apatite cement mixture increased the mechanical strength of apatite cement mixture (p<0.1). The handling property of cement paste was significantly increased between the apatite cement without SCPC50 and apatite cement with both 5% SCPC50 and 10% SCPC50 (p<0.05). It is concluded that the addition of SCPC50 to apatite cement mixture could improve the mechanical properties and it is expected to improve its bioactivity.

Effects of Compression During Formation on the Mechanical Strengths and Physical Properties of Composite Hydroxylapatite/Plaster Implants for Bone Reconstruction

1987 ◽  
Vol 110 ◽  
Author(s):  
K. Cowden ◽  
B. Giammara ◽  
N. Georgiade ◽  
R. Noecker ◽  
J. Hanker
Keyword(s):  
Glass Plate ◽  
Potassium Sulfate ◽  
Surgical Reconstruction ◽  
Hardness Tester ◽  
Setting Times ◽  
Excess Water ◽  
Surgical Implantation ◽  
Mechanical Strengths ◽  
Implantation Procedure ◽  
Scanning Electron

AbstractComposite hydroxylapatite/plaster of Paris implants, preformed or formed during the surgical implantation procedure, are undergoing study for the surgical reconstruction of craniofacial bones. It is frequently necessary to accelerate setting times of the hydroxylapatite/plaster (HA/PP) mixtures by the addition of potassium sulfate; in many of these cases rapid delivery of the moistened implant mixture to the surgical site may be achieved by employing a non-tapered syringe with a plunger. This device can facilitate implantation of quick-setting moistened mixtures through soft tissue tunnels or small incisions, and can result in a less invasive surgical procedure. During experimental surgery it was found beneficial to effect maximum compression of the moistened HA/PP mixture against a sterile glass plate prior to its extrusion from the cylinder. This resulted in elimination of excess water from the mixture. Discs formed from compressed mixtures showed greater mechanical or breaking strengths after setting than discs formed without prior compression when evaluated with a Stokes Hardness-Tester. Examination by light and scanning electron microscopy confirmed the greater compactness of the compressed mixtures.

Diametral Tensile Strength Evaluation of Carbonate Apatite Cement Reinforced by Genipin Cross-Linked Gelatin

2019 ◽  
Vol 829 ◽  
pp. 28-33
Author(s):  
Zatira Avriyanti ◽  
Zulia Hasratiningsih ◽  
Arief Cahyanto
Keyword(s):  
Tensile Strength ◽  
Mechanical Strength ◽  
Weight Ratio ◽  
Control Group ◽  
Carbonate Apatite ◽  
High Porosity ◽  
Bone Substitute Material ◽  
Average Value ◽  
Apatite Cement ◽  
Diametral Tensile Strength

Carbonate apatite is one of the most widely studied bioceramic material for its use as bone cement. On the previous study, it has already stated that CO3Ap cement has good osteoconductivity which makes this cement could be replaced by bone. However, the mechanical strength of CO3Ap cement is still low. This low mechanical strength is estimated due to the high porosity and absence of organic components. The aim of this study is to improve the mechanical strength of the CO3Ap cement reinforced by gelatin as an organic component with genipin as a cross-linking agent (Gelapin). The powder phase of vaterite and DCPA at weight ratio 40:60 were mixed with 0.2 mol/L Na2HPO4, 5% (w/v) gelatin, and 20% (v/v) genipin using 0.5 liquid to powder (L/P) ratio. The liquid phase ratios of Na2HPO4 and Gelapin were 50:50, 70:30, and 90:10. For control group, Gelapin were didn’t mixed in the liquid. Diametral tensile strength was improving and statistically significant (p<0.05) on set cement with 50:50 liquid ratio, the average value was 6.02 ± 0.14 MPa whereas the average value of the control group was only 3.10 ± 0.15 MPa. For this instance, gelatin serves a polymer matrix so the carbonate apatite crystallites could be well distributed within it which then gives more flexibility and resistance for the cement. On the other hand, genipin was also successfully cross-linked the gelatin. This study showed that by reinforcing CO3Ap cement using genipin cross-linked gelatin might be a good candidate for a bone substitute material.

scholarly journals An in vitro confirmation of the ethonopharmacological use of Senna plants as anthelmintic against rumen fluke Paramphistomum gracile

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Saptarshi Roy ◽  
Larisha Mawkhlieng Lyndem
Keyword(s):  
Biochemical Study ◽  
The Body ◽  
Individual Treatment ◽  
Control Group ◽  
Meat Production ◽  
Scanning Electron Micrographs ◽  
Leaf Extracts ◽  
Treatment Groups ◽  
Dose Dependent ◽  
Scanning Electron

Abstract Background Paramphistomosis is a pathogenic disease of domesticated ruminants, causing great economic loss in dairy industry and meat production. It is considered as a neglected tropical disease with highest prevalence throughout tropical and subtropical regions, particularly in Africa, Asia, Europe, and Australia. There are few trematocidal drugs available in the market. Most are resistant and have elevated side effects. Therefore, alternative trematocidal drugs need to discover. This study was conducted to evaluate three plants leaf extracts (from Senna alata, S. alexandrina, and S. occidentalis) as effective remedies against gastrointestinal trematode parasite (Paramphistomum gracile) of ruminants. Live adult parasites were collected in 0.1 M phosphate-buffered saline (PBS) from fresh autopsied goat’s rumen. Parasites were incubated in leaf extracts of S. alata, S. alexandrina and, S. occidentalis individually and in combination (1:1) ratio at 37 ± 1°C. Treatment media contain extracts at different concentrations (10, 20 and 40 mg/mL) in 10 mL of 0.1 M PBS with 1% dimethylsulphoxide (DMSO). Parasites in control group were incubated in PBS without extract. The efficacy of three Senna extracts was evaluated on the basis of dose-dependent motility and mortality of the trematode. Immediately after paralysis, all treated parasites were collected for histology, SEM and biochemical study. Results Dose-dependent efficacy was observed in terms of motility and time of mortality in all treated parasites after exposure in various concentrations of the Senna plant extracts. S. occidentalis and S. alexandrina showed better efficacy in combination than comparing with individual treatment groups. Histological study and scanning electron microscopic observations revealed conspicuous deformity of surface architecture in all treated parasites. Scanning electron micrographs also revealed shrinkage, vacuolization, infoldings and blebbings on the body surface of treated worms. Activities of tegumental enzymes were inhibited in all treatment groups compared to control. Conclusion The overall findings from this study revealed that all three Senna leaf extracts individually and in combination showed potential antitrematocidal activity against Paramphistomum gracile by damaging body tegument and neural propagation. Thus, this study confirmed that all three Senna extracts can be considered as a potential drug-like candidate in indigenous system of traditional medicine against trematode infections in livestock. Graphical abstract

Setting Time Comparison of Four Antimicrobial Laden Calcium Sulfate Plasters

2013 ◽  
Vol 3 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Serkan Inceoglu ◽  
Jared Kroger ◽  
Pierre Beaufond ◽  
Victoria Maskiewicz ◽  
Wayne Cheng ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Calcium Sulfate ◽  
Setting Time ◽  
Control Group ◽  
Initial Setting Time ◽  
General Guideline ◽  
Setting Times ◽  
Initial Setting ◽  
Post Hoc ◽  
Calcium Sulfate Hemihydrate

ABSTRACT Background The surgeon may implant calcium sulfate pellets (aka gypsum) as a resorbable antimicrobial vehicle at the surgical site in severe cases of osteomyelitis. Gypsum setting times with or without antibiotic additives are found scattered throughout the literature, but often factors known to alter setting time are either not disclosed or not held constant between experiments. To our knowledge, no prior study compares the setting time of calcium sulfate plaster mixed with the four commonly used antibiotics under constant conditions as presented here. Purpose To compare the setting times of calcium sulfate hemihydrate mixtures containing vancomycin, cefazolin, tobramycin, or amphotericin B. Materials and methods Groups consisted of samples comprised of 6.3 gm calcium sulfate hemihydrate (CSH) mixed with approximately 1/4th a vial of lyophilized antimicrobial (vancomycin, cefazolin, tobramycin or amphotericin B) with CSH powder to normal saline ratio of 1.7 gm/ml and mixed for 30 seconds at controlled speed and humidity. Each sample initial setting time (Ti) and final setting time (Tf) were established by Gillmore needles method according to ASTM standard C266- 08 apparatus specifications. Results Kruskal-Wallis one-way analysis of variance by ranks revealed that antibiotic type affected the initial and final setting times of gypsum (p < 0.05). Post hoc analysis using Dunn's multiple comparisons indicated that there was no difference between control Ti (7.2 ± 1.1 min) and that of vancomycin or cefazolin group (9.8 ± 1.7 or 14.2 ± 1.3 min, respectively, p > 0.05), but the Ti of the tobramycin and amphotericin B groups (31.8 ± 5.7 and 140.4 ± 18.0 min) differed from the control Ti (p < 0.05). Likewise, there was no difference of control Tf (p > 0.05, 12.2 ± 1.1 min) when compared to vancomycin or cefazolin groups (22.2 ± 6.9 or 25.7 ± 4.1 min), but that the Tf of tobramycin and amphotericin B groups (76.3 ± 5.9 and 200.0 ± 21.1 min) each differed from the control group (p < 0.05). Conclusion This experiment is aimed to help surgeons plan when they should begin preparing their calcium sulfate antibiotic beads during surgery. As a general guideline, allow 15 minutes to set when adding a 1 gm vial of vancomycin or cefazolin, 30 minutes for adding a 1.2 gm vial tobramycin, and 2.5 hours for adding a 50 mg vial of amphotericin B. Kroger J, Beaufond P, Inceoglu S, Maskiewicz V, Cheng W, Brier-Jones JE. Setting Time Comparison of Four Antimicrobial Laden Calcium Sulfate Plasters. The Duke Orthop J 2013;3(1):36-40.

Fracture toughness of macro-defect-free cement using small crack techniques

1990 ◽  
Vol 5 (8) ◽  
pp. 1774-1780 ◽  
Author(s):  
Y-S. Chou ◽  
J. J. Mecholsky ◽  
M. Silsbee
Keyword(s):  
Fracture Toughness ◽  
Fracture Surface ◽  
Crack Growth ◽  
Measurement Techniques ◽  
Crack Growth Resistance ◽  
Scanning Electron Micrographs ◽  
Microstructural Effects ◽  
Fracture Surface Analysis ◽  
Scanning Electron ◽  
Good Agreement

The fracture toughness of a macro-defect-free (MDF) cement was calculated from two measurement techniques: (1) indentation-strength method and (2) fracture surface analysis (FSA). It was found that the indentation-strength method, which showed good agreement with FSA, was applicable for estimating the fracture toughness of MDF cement. The ultimate toughness was found to be 1.25 MPa m1/2 for this MDF cement, which contained 3 wt. % polymer. An R-curve (crack-growth-resistance) bchavior was also observed. Scanning electron micrographs showed extensive microcracking on the fracture surface. Microstructural effects are discussed.

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