Biomimetic Ion-Substituted Calcium Phosphates

2017 ◽  
pp. 333-353
Author(s):  
Jun Ma ◽  
Shenglong Tan ◽  
Shengmin Zhang
Keyword(s):  
Calcium Phosphates

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov
Keyword(s):  
Phase Composition ◽  
Calcium Phosphates ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Phases ◽  
Position Sensitive ◽  
Diffraction Peaks ◽  
Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

A differentiated approach to the dental caries prevention in children with different levels of caries risk

2020 ◽  
Vol 20 (3) ◽  
pp. 211-215
Author(s):  
T. N. Tserakhava ◽  
N. V. Shakavets ◽  
E. I. Melnikava ◽  
M. I. Klenovskaya ◽  
D. N. Naumovich ◽  
...  
Keyword(s):  
Oral Hygiene ◽  
Calcium Phosphates ◽  
Clinical Effectiveness ◽  
Control Group ◽  
Caries Risk ◽  
Health Group ◽  
High Caries Risk ◽  
Permanent Molars ◽  
Different Levels ◽  
First Permanent Molars

Relevance. Prevention of caries of the first permanent molars is one of the most relevant problems in pediatricdentistry.Purpose – to develop an algorithm for prevention of first permanent molars caries in children with differentlevels of caries risk.Materials and methods. The article presents the results of the implementation of the algorithm for prevention of first permanent molars caries in children with different levels of caries risk. This algorithm includes a comprehensive assessment of the values of indices dmft, DMFT, OHI-S, and the patient's health group is also taken into account. The study involved 253 children aged 6-7 years divided into 4 groups: 3 groups of children depending on the health group and the control group. 3 subgroups were identified in each group – with a low, medium, and high caries risk. We developed preventive measures schemes were for children of each group including training in oral hygiene; controlled and home toothbrushing using fluoride-containing toothpastes; applications of varnishes containing fluoride, calcium, phosphates from 2 to 3 times a year; fissure sealing of the first permanent molars. We carried out these activities were for 24 months, and then evaluated theirs effectiveness. Children in the control group were trained in oral hygiene. The clinical effectiveness of medical prophylaxis was evaluated by changes in the above clinical indicators.Results. In group of children with medium caries risk the increase in caries was 0.09, and the reduction in caries was 89.65%. In children with a low and high caries risk no increase in caries was observed; the reduction in the intensity of caries was 100%. A significant decrease in OHI-S oral hygiene index values was noted in all groups (p < 0.05). We noted high preventive efficacy of fissures sealing in the first permanent molars. No occlusal surface caries developed in sealed fissures.Conclusions. The application of the proposed preventive schemes in patients demonstrates high efficacy of fluoride and calcium-containing varnishes and sealing the fissures of the first permanent molars. 

Recent Patents on Nano Calcium Phosphates

2008 ◽  
Vol 1 (3) ◽  
pp. 209-216 ◽  
Author(s):  
Yurong Cai ◽  
Peng Liu ◽  
Ruikang Tang
Keyword(s):  
Calcium Phosphates

scholarly journals Biphasic Calcium Phosphate Biomaterials: Stem Cell-Derived Osteoinduction or In Vivo Osteoconduction? Novel Insights in Maxillary Sinus Augmentation by Advanced Imaging

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2159
Author(s):  
Giovanna Iezzi ◽  
Antonio Scarano ◽  
Luca Valbonetti ◽  
Serena Mazzoni ◽  
Michele Furlani ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Maxillary Sinus ◽  
Biphasic Calcium Phosphate ◽  
Calcium Phosphates ◽  
Three Dimensional ◽  
Sinus Augmentation ◽  
Native Bone ◽  
Maxillary Sinus Augmentation ◽  
Posterior Maxilla

Maxillary sinus augmentation is often necessary prior to implantology procedure, in particular in cases of atrophic posterior maxilla. In this context, bone substitute biomaterials made of biphasic calcium phosphates, produced by three-dimensional additive manufacturing were shown to be highly biocompatible with an efficient osteoconductivity, especially when combined with cell-based tissue engineering. Thus, in the present research, osteoinduction and osteoconduction properties of biphasic calcium-phosphate constructs made by direct rapid prototyping and engineered with ovine-derived amniotic epithelial cells or amniotic fluid cells were evaluated. More in details, this preclinical study was performed using adult sheep targeted to receive scaffold alone (CTR), oAFSMC, or oAEC engineered constructs. The grafted sinuses were explanted at 90 days and a cross-linked experimental approach based on Synchrotron Radiation microCT and histology analysis was performed on the complete set of samples. The study, performed taking into account the distance from native surrounding bone, demonstrated that no significant differences occurred in bone regeneration between oAEC-, oAFMSC-cultured, and Ctr samples and that there was a predominant action of the osteoconduction versus the stem cells osteo-induction. Indeed, it was proven that the newly formed bone amount and distribution decreased from the side of contact scaffold/native bone toward the bulk of the scaffold itself, with almost constant values of morphometric descriptors in volumes more than 1 mm from the border.

Formation and phase evolution of calcium phosphates modulated by ion exchange ionomer Nafion

CrystEngComm ◽  
2020 ◽  
Vol 22 (47) ◽  
pp. 8243-8250
Author(s):  
Shuquan Sun ◽  
Qixuan Chen ◽  
Qijun Song
Keyword(s):  
Phase Transition ◽  
Ion Exchange ◽  
Calcium Phosphates ◽  
Phase Evolution

The phase transition of calcium phosphates regulated by Nafion with the inherent acidity and ion exchange features.

scholarly journals Mineralization of Titanium Surfaces: Biomimetic Implants

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2879
Author(s):  
Javier Gil ◽  
Jose Maria Manero ◽  
Elisa Ruperez ◽  
Eugenio Velasco-Ortega ◽  
Alvaro Jiménez-Guerra ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Dental Implants ◽  
Early Stage ◽  
Calcium Phosphates ◽  
Biological Fixation ◽  
Biomimetic Surfaces ◽  
Titanium Surfaces ◽  
Deposition Processes ◽  
Fast Dissolution ◽  
Plasma Sprayed

The surface modification by the formation of apatitic compounds, such as hydroxyapatite, improves biological fixation implants at an early stage after implantation. The structure, which is identical to mineral content of human bone, has the potential to be osteoinductive and/or osteoconductive materials. These calcium phosphates provoke the action of the cell signals that interact with the surface after implantation in order to quickly regenerate bone in contact with dental implants with mineral coating. A new generation of calcium phosphate coatings applied on the titanium surfaces of dental implants using laser, plasma-sprayed, laser-ablation, or electrochemical deposition processes produces that response. However, these modifications produce failures and bad responses in long-term behavior. Calcium phosphates films result in heterogeneous degradation due to the lack of crystallinity of the phosphates with a fast dissolution; conversely, the film presents cracks, which produce fractures in the coating. New thermochemical treatments have been developed to obtain biomimetic surfaces with calcium phosphate compounds that overcome the aforementioned problems. Among them, the chemical modification using biomineralization treatments has been extended to other materials, including composites, bioceramics, biopolymers, peptides, organic molecules, and other metallic materials, showing the potential for growing a calcium phosphate layer under biomimetic conditions.

Hydrogen Bonding in Apatitic Calcium Phosphates

Nature ◽  
1961 ◽  
Vol 190 (4771) ◽  
pp. 164-165 ◽  
Author(s):  
LOUIS WINAND ◽  
M. J. DALLEMAGNE ◽  
G. DUYCKAERTS
Keyword(s):  
Hydrogen Bonding ◽  
Calcium Phosphates

“Titanium–Silver-Substituted Calcium Phosphates” Plasma Coatings: Properties, Comparison, and Prospects of Application

Metallurgist ◽  
2018 ◽  
Vol 62 (7-8) ◽  
pp. 831-836 ◽  
Author(s):  
A. V. Lyasnikova ◽  
O. A. Markelova ◽  
O. A. Dudareva ◽  
I. P. Grishina ◽  
V. N. Lyasnikov
Keyword(s):  
Calcium Phosphates ◽  
Plasma Coatings ◽  
Prospects Of Application
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