hydroxy apatite
Recently Published Documents


TOTAL DOCUMENTS

140
(FIVE YEARS 22)

H-INDEX

19
(FIVE YEARS 1)

Author(s):  
Sergio Charifker Ribeiro Martins

The use of guided bone regeneration (GBR) has been gaining more and more ground in the field of implant dentistry, due to higher confidence in the materials available. As this is a highly versatile technique, the same biological basis-cell exclusion–can be used to treat any type of defect. Vertical augmentation in the alveolar ridge is currently treated by the GBR principle, predictably and with high success rates, using a rigid framework associated with a mix of hydroxyapatite and autogenous bone. Lyophilized bovine bone is the hydroxyapatite of choice for this condition because it allows bone volume to be maintained over a long period of time, due to its slow resorption. Another important char-acteristic found in hydroxyapatite is its porosity since it allows – in addition to graft neo-vascularization–a greater ease of cell adhesion when compared to crystalline materials. Thus, this clinical case presents the use (for the first time in the literature) of a vertical augmentation of an atrophic ridge using Criteria Lumina Bone Porous® as the hydroxy-apatite of choice for association with autogenous bone particles.


2021 ◽  
Author(s):  
Michael E. Böttcher ◽  
Nikolaus Gussone ◽  
Anika C. Conrad ◽  
Iris Schmiedinger ◽  
Jens Fiebig ◽  
...  

<p>Carbonated hydroxy-apatite (CHAP) was experimentally synthesized in batch-type set-ups by mixing of calcium (Ca)- and phosphate-bearing aqueous solutions and the transformation of calcite powder in aqueous solution between 11° and 65°C (Gussone et al., 2020). Compositional changes of the experimental solution and solid phase products were followed by elemental analysis, Raman spectroscopy, scanning-electron microscopy, and powder XRD. In the mixing experiments, crystallization of CHAP took place following the precipitation of metastable brushite as precursor that was then transformed into CHAP. In the transformation experiments using synthetic calcite as a precursor phase it was found that the reaction at pH values between 7.5 and 7.9 occurs via the direct replacement of calcium carbonate by CHAP.</p><p>Calcium isotope fractionation led to an enrichment of the light isotope in the solid CHAP compared to the aqueous solution by about -0.5 to -1.1 ‰, independent from the experimental approach, and the magnitude was essentially independent of temperature. The metastable brushite formed prior to transformation to CHAP showed a reduced fractionation compared to the CHAP. The observed Ca isotope fractionation into the CHAP lattice resembles that of natural phosphorites and lies within the range of the view existing theoretical and experimental studies.</p><p> </p><p>Reference: Gussone N., Böttcher M.E., Conrad A.C., Fiebig J., Pelz M., Grathoff G., Schmidt B.C. (2020) Calcium isotope fractionation upon experimental apatite formation. Chem. Geol., 551, 119737</p><p>The study was supported by German Science Foundation (DFG) to M.E.B and J.F. within the EXCALIBOR project (BO1548/8 and FI 948/7), and to N.G. (GU1035/10), and by Leibniz IOW.</p>


2021 ◽  
Author(s):  
Rajendra Prasad ◽  
Yashbir Singh Shivay

Phosphorus is a major plant nutrient obtained from non-renewable phosphate rock, which is not much available in India. Over and above in this its recovery efficiency in crops hardly exceeds 15-20 per cent. Utmost care is therefore required in its use. Phosphorus applied to soil gets fixed by the formation of insoluble reaction products by reacting with Fe and Al in acid soils and with calcium in saline and alkaline soils. Two techniques used for identification of reaction products are X-ray diffraction and solubility product principle. In addition, phosphate ions are also held on Fe and Al hydroxides by anion exchange. The reaction products identified are variscite and strengite minerals in acid soils and dicalcium phosphate and hydroxy apatite in calcareous soils. Methods to increase phosphorus recovery by crops include: 1) addition of organic matter to soils; 2) addition of sulphur to compost or to ground rock phosphate or directly to soil and use of phosphorus solubilising organisms including VAM/AM along with ground rock phosphate.


2021 ◽  
Author(s):  
Ronald Joseph Turner ◽  
Pieter Bots ◽  
Alan Richardson ◽  
Paul Bingham ◽  
Alex Scrimshire ◽  
...  

(Hydroxy)apatite [Ca10(PO4)6(OH)2], has emerging potential as a cement coating material, with applications in environmental remediation, nuclear waste storage and architectural preservation. In these low temperature environments and when precipitating from...


Author(s):  
Pragyan Paramita ◽  
Murugesan Ramachandran ◽  
Srinivasan Narashiman ◽  
Selvamurugan Nagarajan ◽  
Dinesh Kumar Sukumar ◽  
...  

AbstractBone is a flexible and electro active tissue that is vulnerable to various traumatic injuries. The self-healing of damaged bone tissue towards reconstruction is limited due to the lack of proper niche compliances. Nevertheless, the classical grafting techniques like autograft/allograft for bone repair pose challenges like bacterial infections and donor-site morbidity with unsatisfactory outcomes. The use of appropriate biomaterial with osteogenic potential can meet these challenges. In this regard, bioactive glass ceramics is widely used as a bone filler or graft material because of its bonding affinity to bone leading towards bone reconstruction applications without the challenge of post implant infections. Hence, the current study is aimed at addressing this potentiality of zinc (Zn) for doped the bioglass at nano-scale advantages for bone tissue repair. Since, Zn has been demonstrated to have not only antibacterial property but also the stimulatory effect on osteoblasts differentiation, mineralization by enhancing the osteogenic genes expression. In view of these, the present study is focused on sol–gel synthesis and pysico-chemical characterization of Zinc-doped bioglass nanoparticles (Zn-nBGC) and also analyzing its biological implications. The surface morphological and physiochemical characterizations using SEM, EDX, FT-IR and XRD analysis has shown the increased surface area of Zn-nBGC particles providing a great platform for biomolecular interaction, cytocompatibility, cell proliferation and osteogenic differentiation. The obtaining hydroxy apatite groups have initiated in vitro mineralization towards osteogenic lineage formation. Zn has not only involved in enhancing cellular actions but also strengthen the ceramic nanoparticles towards antibacterial application. Hence the finding suggests a biomaterial synthesis of better biomaterial for bone tissue engineering application by preventing post-operative bacterial infection.


Author(s):  
Shubrajit Bhaumik ◽  
Rajeswar Bandyopadhyay ◽  
Tanveer Ahamed Rohit ◽  
Anik Banerjee ◽  
Helen Annal Therese ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document