Effects of Setting Liquid on α-Calcium Phosphate-Tetracalcium Phosphate Bone Cement

2007 ◽  
Vol 336-338 ◽  
pp. 1622-1624
Author(s):  
Xu Li ◽  
De An Yang ◽  
Li Zhi Di

Calcium phosphate cement (CPC) is a kind of promising materials used in dental and orthopeadic restoration. Nowadays, CPC is of special interest due to its self-setting behavior when mixed with an aqueous liquid phase. In this study, α-tricalcium phosphate (α-TCP) and tetracalcium phosphate (TeCP) were served as the solid component of the cement, and the liquid component was consisted of sodium phosphate dibasic dedocahydrate (SPDD, Na2HPO4·12H2O), and/or citric acid. The cement’s properties as compressive strength and porosity were measured. The effects of preparing conditions, such as liquid-to-powder ratio (L/P) and liquid composition, on compressive strength of calcium phosphate were investigated. The results show that the compressive strength increases with the decreasing of pH value. There is a premium L/P in which the compressive strength gains its maxim. The compressive strength reached 21.69 MPa at the condition of L/P = 0.30mL/g and pH =5.

2006 ◽  
Vol 309-311 ◽  
pp. 857-860 ◽  
Author(s):  
Q. Yao ◽  
Dong Xiao Li ◽  
K.W. Liu ◽  
Bo Zhang ◽  
H. Li ◽  
...  

This study was to develop an injectable biocompatible and porous calcium phosphate collagen composite cement scaffold by in situ setting. TTCP was prepared as main material of the CPC powder, and the collagen solution was added into the phosphoric acid directly to form the liquid phase. The injectable time (tI), setting time (tS) and setting temperature (TS), along with the PH value were recorded during the setting process. The compressive strength, morphology and porosity were tested. With the increase of collagen, this novel CPC get a tI of 5mins to 8mins, tS of 20mins to 30mins, compressive strength from 1.5MPa to 4MPa, and the porosity from 40% to 60%. This study gave a possibility to form a porous scaffold of collagen/CPC composite with the nature of injectability and setting in situ.


2012 ◽  
Vol 550-553 ◽  
pp. 1133-1138 ◽  
Author(s):  
Rui Juan Xie ◽  
Yang Yang Huang ◽  
Biao Wang ◽  
Meng Zhang

In this study, the high purity tetracalcium phosphate (TTCP) was prepared conveniently after studying the effect of cooling method on the purity of TTCP. The influence of liquid-to-powder (L/P) ratio on the properties of self-setting silk fibroin/calcium phosphate composites was studied. The results showed that the temperature of the furnace had a significant influence on the purity of TTCP when samples were removed from the furnace. Whether using N2 or not had no obvious effect on the purity of TTCP when the temperature declined from 1500°C to 1300°C. The setting time of composites became longer with the increase of L/P ratio in a range 0.32 - 0.39 ml/g, but all less than 15min. The injectability of the composites improved significantly as the L/P ratio increased. The compressive strength of composites reached maximum at the L/P ratio of 0.34 ml/g. The compressive strength decreased with the increase of L/P ratio greater than 0.34ml/g. The L/P ratio had no significant effect on the structure of the composites and the rod-like crystal of hydroxyapatite appeared in all the hardening-body of composites.


2020 ◽  
Vol 20 (1) ◽  
pp. 56-75
Author(s):  
Lubomir Medvecky ◽  
Radoslava Stulajterova ◽  
Maria Giretova ◽  
Tibor Sopcak ◽  
Maria Faberova ◽  
...  

Abstract Tetracalcium phosphate/monetite biocement was modified with 10 and 30 wt. % addition of highly porous silicon nitride/α-tricalcium phosphate (αTCP) microgranules with various content of αTCP. A composite cement powder mixture was prepared using mechanical homogenization of basic components. The accelerated release of dexamethasone from composite cement was revealed, which indicates their possible utilization for controlled drug release. The wet compressive strength of cements (<17 MPa) was significantly reduced (more than 30%) in comparison with the unmodified cement and both compressive strength and setting time were influenced by the content of αTCP in microgranules. The addition of microgranules caused a 20% decrease in final cement density. Microgranules with a higher fraction of αTCP showed good in vitro SBF bioactivity with precipitation of hydroxyapatite particles. Microstructure analysis of fractured cements demonstrated excellent interconnection between microgranules and cement calcium phosphate matrix, but also showed lower mechanical strength of microgranule cores.


2012 ◽  
Vol 531 ◽  
pp. 88-92
Author(s):  
Hua Liu ◽  
Min Ying Zhu ◽  
Wen Jun Cheng

We developed a calcium phosphate cement that could be molded into any desired shape due to its chewing-gum-like consistency after mixing. The powder component of the cement consists of tricalcium phosphate (TCP). The liquid component consists of chitosan, citric acid and glucose solution. In this study, we used four groups of cement to investigate the mechanical properties and biocompatibility of the new biomaterial in vivo. The setting times of the cements were 5-30 min. X-ray diffraction analysis showed that the products were hydroxyapatite (HA) and dicalcium phosphate anhydrous. When the concentration of citric acid was increased, the compressive strength of specimen increased. The animal experiments showed that the material was nontoxic and osteoinductivity.


2017 ◽  
Vol 17 (1) ◽  
pp. 1-9
Author(s):  
L. Medvecky ◽  
R. Stulajterova ◽  
M. Giretova ◽  
M. Faberova

Abstract Prepared powder polyhydroxybutyrate – chitosan - calcium phosphate composite system with 10 wt % of biopolymer component can be utilized as biocement which is characterized by the prolonged setting time and achieves wash out resistance after 5 minutes of setting. The origin powder tetracalcium phosphate/nanomonetite agglomerates were coated with the thin layer of biopolymer which decelerates both the transformation rate of calcium phosphates and hardening process of composites. The porosity of hardened composite was around 62% and the compressive strength (8 MPa) was close to trabecular bone. No cytotoxicity of composite resulted from live/dead staining of osteoblasts cultured on substrates.


2007 ◽  
Vol 361-363 ◽  
pp. 347-350
Author(s):  
J.Y. Gong ◽  
Shu Xin Qu ◽  
Q. Cui ◽  
Jie Weng

In the present study, ZrO2 was added into the injectable calcium phosphate cements (CPCs) to improve their mechanical strength. Different mass fractions of ZrO2 (5 %, 10 %, 15 %, 20%) were mixed with the powder components consisted of tricalcium phosphate (α-TCP) and hydroxyapatite (HA). Then formed the paste via adding the liquid component consisted of citric acid. The compressive strength, the injectability, the initial setting time and finial time of CPC were measured, respectively. X-ray diffraction (XRD) was employed to analyse the phase of as-prepared CPC. Scanning Electron Microscope (SEM) and Energy dispersive spertrum (EDS) were used to observe the morphology and indicate the element components of CPC. The compressive strength of ZrO2-CPC was higher than that of CPC without added ZrO2. The compressive strength got the maximal when the mass fraction of ZrO2 was 15%. It had no effect on the injectability with adding ZrO2, which were 89 % to 92 %. It had a slight down-regulation of the initial and final setting time with adding ZrO2. SEM showed that there was amounts needle-like substance in CPC, which might be related to the improvement of compressive strength of CPC. XRD showed that there were HA, a few of α-TCP and ZrO2 diffraction peaks in CPCs. The present results indicate that it is feasible to improve the compressive strength of injectable CPC via adding ZrO2.


2016 ◽  
Vol 705 ◽  
pp. 309-314 ◽  
Author(s):  
Salina Sabudin ◽  
Sudirman Sahid ◽  
Nor Shahida Kader Bashah ◽  
Shirin Ibrahim ◽  
Zul Hazmi Hussin ◽  
...  

In this study, the effects of macroporous calcium phosphate (MCP) scaffold on bioactivity as an in-vitro model has been investigated. MCP scaffold was prepared using foam replication technique by combination of ceramic and polyurethane (PU). MCP was examined by scanning electron microscope (SEM) and X-ray diffractometer (XRD) to confirm its microstructure and phase composition respectively. Bioactivity in simulated body fluid (SBF) was characterized by apatite mineralisation on MCP scaffold surface, pH, calcium (Ca2+) and phosphate (PO43-) ion dissolution and compressive strength using universal testing machine (UTM). Experimental results showed the formation of apatite around the MCP scaffold after 30 days in SBF. pH value was gradually decreased up to 7 days and constant until 30 days. Dissolution of Ca2+ and PO43- ion in SBF due to the occurrence of MCP degradation, hence the compressive strength are gradually decreased gradually in line with immersion period. This material may be promising for biomedical application.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2137
Author(s):  
Lubomir Medvecky ◽  
Maria Giretova ◽  
Radoslava Stulajterova ◽  
Lenka Luptakova ◽  
Tibor Sopcak

A modified one-step process was used to prepare tetracalcium phosphate/monetite/calcium sulfate hemihydrate powder cement mixtures (CAS). The procedure allowed the formation of monetite and calcium sulfate hemihydrate (CSH) in the form of nanoparticles. It was hypothesized that the presence of nanoCSH in small amounts enhances the in vitro bioactivity of CAS cement in relation to osteogenic gene markers in mesenchymal stem cells (MSCs). The CAS powder mixtures with 15 and 5 wt.% CSH were prepared by milling powder tetracalcium phosphate in an ethanolic solution of both orthophosphoric and sulfuric acids. The CAS cements had short setting times (around 5 min). The fast setting of the cement samples after the addition of the liquid component (water solution of NaH2PO4) was due to the partial formation of calcium sulfate dihydrate and hydroxyapatite before soaking in SBF with a small change in the original phase composition in cement powder samples after milling. Nanocrystalline hydroxyapatite biocement was produced by soaking of cement samples after setting in simulated body fluid (SBF). The fast release of calcium ions from CAS5 cement, as well as a small rise in the pH of SBF during soaking, were demonstrated. After soaking in SBF for 7 days, the final product of the cement transformation was nanocrystalline hydroxyapatite. The compressive strength of the cement samples (up to 30 MPa) after soaking in simulated body fluid (SBF) was comparable to that of bone. Real time polymerase chain reaction (RT-PCR) analysis revealed statistically significant higher gene expressions of alkaline phosphatase (ALP), osteonectin (ON) and osteopontin (OP) in cells cultured for 14 days in CAS5 extract compared to CSH-free cement. The addition of a small amount of nanoCSH (5 wt.%) to the tetracalcium phosphate (TTCP)/monetite cement mixture significantly promoted the over expression of osteogenic markers in MSCs. The prepared CAS powder mixture with its enhanced bioactivity can be used for bone defect treatment and has good potential for bone healing.


2021 ◽  
Vol 5 (1) ◽  
pp. 30
Author(s):  
Angelica Bertacci ◽  
Daniele Moro ◽  
Gianfranco Ulian ◽  
Giovanni Valdrè

Recently, endodontic sealers based on injectable bioactive materials were proposed to improve the filling of anatomical irregularities during root canal obturation. In this context, this preliminary work investigated the possibility of realizing a new calcium phosphate-based composite sealer for root canal filling with an optimized composition on setting kinetics and dentin tubules occlusion. Several calcium phosphate/liquid phase mixtures were initially evaluated for their workability, finding two suitable formulations. Both of them contained 66 wt.% of a nano-apatite-based cement (solid powdered phase). The liquid phase (34 wt.%) comprised 13.6% propanediol and 20.4% PEG 1000 (formulation 1), and formulation 2 comprised 27.2% glycerin and 6.8% PEG 200 (formulation 2). Then, these formulations were tested by means of permeability measurements and observation by scanning electron microscopy of treated model dentin samples. Both formulations succeeded in occluding dentinal tubules: the first one was able to create a full-bodied layer on dentin surface and, moreover, to resist, at least to a large extent, against citric acid attack. The second one showed a lower effectiveness after citric acid exposure. The composite compound that better satisfied the overall required characteristics of use, workability and sealing capacity was formulation 1.


2020 ◽  
Author(s):  
Changtian Gong ◽  
Shuo Fang ◽  
Kezhou Xia ◽  
Jingteng Chen ◽  
Liangyu Guo ◽  
...  

Abstract Incorporating bioactive substances into synthetic bioceramic scaffolds is challenging. In this work, oxygen-carboxymethyl chitosan (O-CMC), a natural biopolymer that is nontoxic, biodegradable and biocompatible, was introduced into magnesium potassium phosphate cement (K-struvite) to enhance its mechanical properties and cytocompatibility. This study aimed to develop O-CMC/magnesium potassium phosphate composite bone cement (OMPC), thereby combining the optimum bioactivity of O-CMC with the extraordinary self-setting properties and mechanical intensity of the K-struvite. Our results indicated that O-CMC incorporation increased the compressive strength and setting time of K-struvite and decreased its porosity and pH value. Furthermore, OMPC scaffolds remarkably improved the proliferation, adhesion and osteogenesis related differentiation of MC3T3-E1 cells. Therefore, O-CMC introduced suitable physicochemical properties to K-struvite and enhanced its cytocompatibility for use in bone regeneration.


Sign in / Sign up

Export Citation Format

Share Document