Stability of Ultrathin Amorphous Calcium Phosphate Artificial Enamel Sheets under Simulated Intraoral Environment Condition

2019 ◽  
Vol 829 ◽  
pp. 16-20
Author(s):  
Nobuhiro Kato ◽  
Mizuki Hirai ◽  
Ei Yamamoto ◽  
Shigeki Hontsu
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Dental Materials ◽  
Cross Sectional ◽  
Sem Image ◽  
Long Term Stability ◽  
Optical Images ◽  
Surface Morphologies ◽  
Environment Condition

Dental materials purely composed of calcium phosphate are ideal for the dental medicine. We have been developing ultrathin amorphous calcium phosphate (ACP) sheets for enamel repair. In this study, long term stability of the ultrathin ACP sheets applied on enamel surfaces which kept in a simulated intraoral condition for 21 days was evaluated. Surface morphologies of the ACP sheets were observed by optical images. A boundary condition between the ACP sheet and the enamel was evaluated by cross-sectional SEM image. A durability of the ACP sheet was evaluated by a brushing test conducted after 21 days incubation. As the result of these evaluations, it was confirmed that the ACP sheets were stable even after long-term incubation under the simulated intraoral environment condition.

Functionalized Calcium Phosphate-based Nanoparticles for the Treatment of Osteoporosis

2005 ◽  
Vol 873 ◽  
Author(s):  
Balasundaram G ◽  
Sato M ◽  
Webster TJ
Keyword(s):  
Calcium Phosphate ◽  
Bone Formation ◽  
Amorphous Calcium Phosphate ◽  
Bone Growth ◽  
Osteoporotic Bone ◽  
Amino Groups ◽  
Calcium Phosphate Nanoparticles ◽  
Bioactive Agents ◽  
Bone Growth Factor

AbstractIn an effort to decrease the number of problems associated with osteoporosis, the long-term goal of the present study is to design calcium phosphate-based nanoparticles that specifically attach to areas of low bone density and once attached, allow for the targeted release of bioactive agents that can quickly increase bone formation. Efforts are focused on nanoparticles of calcium phosphate-based materials since they are similar in size and chemistry to the major inorganic components of bone. As a first step in this research, the objective of the present study was to synthesize nanoparticles of crystalline hydroxyapatite (or HA) and amorphous calcium phosphate. Crystalline HA is stable under physiological fluids and, thus, will release embedded bioactive agents slowly. Alternatively, amorphous calcium phosphate is highly biodegradable and will, thus, release embedded bioactive agents quickly. A further objective of the present study was to functionalize such inorganic biodegradable materials with amino groups which would allow for the subsequent attachment of entities to direct such nanoparticles to osteoporotic bone and increased bone formation once attached. One promising approach to direct the nanoparticles to osteoporotic bone is to attach antibodies to pentosidine on the nanoparticles since pentosidine is present in higher amounts in osteoporotic compared to healthy bone. A promising approach to increase bone growth once nanoparticles attach to osteoporotic bone, is to embed nanoparticles with regions of the bone growth factor: bone morphogenic protein-2 (or BMP-2). Results of this study demonstrated the successful synthesis of both crystalline HA and amorphous calcium phosphate nanoparticles. Furthermore, results showed that these nanoparticles can be functionalized with versatile amino groups. In this manner, this study takes the first steps toward utilizing calcium phosphate based nanoparticles to reverse bone loss associated with osteoporosis.

scholarly journals Long-term mechanical durability of dental nanocomposites containing amorphous calcium phosphate nanoparticles

2012 ◽  
Vol 100B (5) ◽  
pp. 1264-1273 ◽  
Author(s):  
Jennifer L. Moreau ◽  
Michael D. Weir ◽  
Anthony A. Giuseppetti ◽  
Laurence C. Chow ◽  
Joseph M. Antonucci ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Mechanical Durability ◽  
Calcium Phosphate Nanoparticles

Why settle when there are plenty of fish in the sea? Rusbult’s investment model applied to online dating

2020 ◽  
pp. 146144482093766
Author(s):  
Liesel L Sharabi ◽  
Elisabeth Timmermans
Keyword(s):  
Online Dating ◽  
Investment Model ◽  
Mixed Methods Study ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Long Term Stability ◽  
Lower Likelihood ◽  
Dating Relationship

The current mixed-methods study reports the results of a cross-sectional survey of 205 online daters and uses the Investment Model to examine the antecedents of commitment in online dating and users’ decisions to delete their online dating account(s). We hypothesized that the quality of alternatives, investments, and satisfaction with the online dating relationship would mediate the association between online dating intensity and commitment, which, in turn, would predict the intention to terminate an account. The analyses revealed that online dating intensity was associated with greater commitment and a lower likelihood of account termination. There were also specific indirect effects on commitment through the quality of alternatives, investments, and satisfaction, and on termination through investments. Responses to an open-ended question provided more information about users’ decisions to quit online dating. These results point to ways online dating may facilitate the desire for commitment while potentially undermining the long-term stability of relationships.

scholarly journals Tuning Nano-Amorphous Calcium Phosphate Content in Novel Rechargeable Antibacterial Dental Sealant

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1544 ◽  
Author(s):  
Maria Ibrahim ◽  
Faisal AlQarni ◽  
Yousif Al-Dulaijan ◽  
Michael Weir ◽  
Thomas Oates ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Flexural Strength ◽  
Amorphous Calcium Phosphate ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Dental Materials ◽  
Ion Release ◽  
Dental Sealants ◽  
Mass Fractions ◽  
The Impact

Dental sealants with antibacterial and remineralizing properties are promising for caries prevention among children and adolescents. The application of nanotechnology and polymer development have enabled nanoparticles of amorphous calcium phosphate (NACP) and dimethylaminohexadecyl methacrylate (DMAHDM) to emerge as anti-caries strategies via resin-based dental materials. Our objectives in this study were to (1) incorporate different mass fractions of NACP into a parental rechargeable and antibacterial sealant; (2) investigate the effects on mechanical performance, and (3) assess how the variations in NACP concentration would affect the calcium (Ca) and phosphate (PO4) ion release and re-chargeability over time. NACP were synthesized using a spray-drying technique and incorporated at mass fractions of 0, 10, 20 and 30%. Flexural strength, flexural modulus, and flowability were assessed for mechanical and physical performance. Ca and PO4 ion release were measured over 70 days, and three ion recharging cycles were performed for re-chargeability. The impact of the loading percentage of NACP upon the sealant’s performance was evaluated, and the optimized formulation was eventually selected. The experimental sealant at 20% NACP had flexural strength and flexural modulus of 79.5 ± 8.4 MPa and 4.2 ± 0.4 GPa, respectively, while the flexural strength and flexural modulus of a commercial sealant control were 70.7 ± 5.5 MPa (p > 0.05) and 3.3 ± 0.5 GPa (p < 0.05), respectively. A significant reduction in flow was observed in the experimental sealant at 30% NACP (p < 0.05). Increasing the NACP mass fraction increased the ion release. The sealant formulation with NACP at 20% displayed desirable mechanical performance and ideal flow and handling properties, and also showed high levels of long-term Ca and PO4 ion release and excellent recharge capabilities. The findings provide fundamental data for the development of a new generation of antibacterial and rechargeable Ca and PO4 dental sealants to promote remineralization and inhibit caries.

scholarly journals Long-term water sorption and solubility of experimental bioactive composites based on amorphous calcium phosphate and bioactive glass

2019 ◽  
Vol 38 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Matej PAR ◽  
Nika SPANOVIC ◽  
Ruza BJELOVUCIC ◽  
Danijela MAROVIC ◽  
Gottfried SCHMALZ ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Bioactive Glass ◽  
Amorphous Calcium Phosphate ◽  
Water Sorption ◽  
Bioactive Composites

scholarly journals Nanocomposites based on apatitic tricalcium phosphate and autofibrin

2021 ◽  
Vol 57 (4) ◽  
pp. 413-423
Author(s):  
I. E. Glazov ◽  
V. K. Krut’ko ◽  
R. A. Vlasov ◽  
O. N. Musskaya ◽  
A. I. Kulak
Keyword(s):  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Calcium Phosphates ◽  
Fibrin Clot ◽  
Combined Effect ◽  
Morphological Properties ◽  
Maturation Time ◽  
Soluble Calcium

Nanocomposites based on apatitic tricalcium phosphate in an autofibrin matrix were obtained by precipitation at a Ca/P ratio of 1.50, pH 9 and a maturation time from 30 min to 7–14 days. The resorbability of nanocomposites was determined by the composition of calcium phosphates, which, during long-term maturation, formed as the calcium-deficient hydroxyapatite with a Ca/P ratio of 1.66, whereas biopolymer matrix favored the formation of more soluble calcium phosphates with a Ca/P ratio of 1.53–1.59. It was found that the fibrin clot stabilized, along with apatitic tricalcium phosphate, the phase of amorphous calcium phosphate, which after 800 °C was transformed into resorbable α-tricalcium phosphate. Citrated plasma inhibited the conversion of apatitic tricalcium phosphate into stoichiometric hydroxyapatite, which also facilitated the formation of resorbable β-tricalcium phosphate after 800 °C. The combined effect of the maturation time and the biopolymer matrix determined the composition, physicochemical and morphological properties of nanocomposites and the possibililty to control its extent of resorption

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