scholarly journals Effect of Different Formulations and Application Methods of Coral Calcium on its Remineralization Ability on Carious Enamel

2020 ◽  
Vol 8 (D) ◽  
pp. 94-99
Author(s):  
Ali Abdelnabi ◽  
Mermen Kamal Hamza ◽  
Ola M. El-Borady ◽  
Tamer M. Hamdy
Keyword(s):  
Calcium Level ◽  
Mineral Content ◽  
Argon Laser ◽  
Calcium Content ◽  
Chemical Precipitation ◽  
Control Group ◽  
X Rays ◽  
Ft Ir ◽  
Ir Analysis ◽  
Application Methods

BACKGROUND: Coral calcium is a new biomimetic product and dietary supplement which consists mainly of alkaline calcium carbonate. AIM: The aim of the current study is to compare the remineralization effect of coral calcium in different formulations and application methods. METHODS: A total of 35 extracted molars was collected, examined, and sectioned to obtain 70 sound enamel discs, all specimens were examined for calcium mineral content using energy dispersive analysis of X-rays (EDAX) coupled with scanning electron microscope. Hydroxyapatite (HA) nanoparticles were synthesized through wet chemical precipitation approach and characterized by transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) analysis. Teeth specimens were subjected to demineralization, and mineral content was measured, specimens were divided into ten groups according to the remineralizing agent used, where Groups 1–3 used 10, 20, and 30 weight % (wt.%) coral calcium gel, respectively, Groups 4–6 used 10, 20, and 30 wt.% coral calcium and nanohydroxyapatite mix gel, and Groups 7–9 used 10, 20, and 30 wt.% coral calcium with argon laser activation and Group 10 (control group) without a remineralizing agent. All groups were re-examined by EDAX after remineralization. RESULTS: The TEM and FT-IR analysis confirmed the formation of rod shape HA in nanoparticles size range. All groups showed a statistically significant decrease in calcium level after demineralization, all groups showed a statistically significant increase in calcium content after remineralization except for the control group. Moreover, Groups 2 and 8 showed the highest increase in calcium level after remineralization. CONCLUSION: Coral calcium showed a significant remineralizing effect on carious enamel (demineralization) with an optimum concentration of 20 wt.%.

scholarly journals Effect of Yttrium Oxide in Hydroxyapatite Biocomposite Materials: Electrical and Antimicrobial Evaluation

2021 ◽  
Author(s):  
G. M. Turky ◽  
Esmat Hamzawy ◽  
Gehan Bassyouny ◽  
Sayed Kenawy ◽  
Abeer A. Abd El-Aty
Keyword(s):  
Yttrium Oxide ◽  
Pathogenic Bacteria ◽  
Chemical Precipitation ◽  
Antimicrobial Activities ◽  
X Rays ◽  
Ionic Radii ◽  
Ft Ir ◽  
Mussel Shells ◽  
Bacteria And Fungi ◽  
Xrd Patterns

Abstract Synthesis and characterization of biocomposite materials of hydroxyapatite (HA) and yttrium oxide (Y2O3) were investigated. HA nanoparticles powder was obtained from mussel shells via a wet chemical precipitation routine. HA powder was doped with 1 and 2 wt% of Y2O3 . For microstructural examination, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) coupled with energy dispersive X-rays (EDX) were used. In addition, the dielectric and electrical properties and antimicrobial activities were investigated. XRD patterns reveal the crystallization of the oxyapatite. The peak intensities of pristine HA are inferior compared to the yttrium containing HA composites, thus suggesting that the addition of yttrium promotes the crystallization of HA due to the variance in their ionic radii. FT-IR shows a variation in the phosphate wavenumber, indicating the integration of yttrium into the HA matrix. SEM reveals nanorod- or worm-like crystals arose in clusters. With increasing Y2O3, from 1 to 2 wt%, the DC conductivity reduces from 16 to 9.3 nS/cm, which confirms that high amounts of Y3+ substitute Ca2+ in the HA matrix. In the high-frequency range, the AC conductivity linearly increases with increasing frequency following the universal power law. Further, antimicrobial activity results showed that the addition of yttrium in HA improves the antimicrobial effects against pathogenic bacteria and fungi. Additional research is needed to investigate the doping concentration of yttrium ions, and an anticipated property could be comprehended for several forthcoming biomedical applications

Polarized microbeam FT-IR analysis of single fibers

1996 ◽  
Vol 54 ◽  
pp. 206-207
Author(s):  
Liling Cho ◽  
David L. Wetzel
Keyword(s):  
Molecular Orientation ◽  
Transition Point ◽  
Polymer Fibers ◽  
Single Fiber ◽  
Wire Grid ◽  
Polyester Fibers ◽  
Ft Ir ◽  
Ir Analysis ◽  
The Relationship ◽  
Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

Computed Tomography-Based Patient-Specific Instrumentation Loses Accuracy with Significant Varus Preoperative Misalignment

2020 ◽  
Author(s):  
Vicente Jesús León-Muñoz ◽  
Mirian López-López ◽  
Alonso José Lisón-Almagro ◽  
Francisco Martínez-Martínez ◽  
Fernando Santonja-Medina
Keyword(s):  
Computed Tomography ◽  
Deformity Correction ◽  
Patient Specific ◽  
Control Group ◽  
X Rays ◽  
Varus Alignment ◽  
Patient Specific Instrumentation ◽  
Conventional Instrumentation ◽  
The Mean ◽  
Valgus Alignment

AbstractPatient-specific instrumentation (PSI) has been introduced to simplify and make total knee arthroplasty (TKA) surgery more precise, effective, and efficient. We performed this study to determine whether the postoperative coronal alignment is related to preoperative deformity when computed tomography (CT)-based PSI is used for TKA surgery, and how the PSI approach compares with deformity correction obtained with conventional instrumentation. We analyzed pre-and post-operative full length standing hip-knee-ankle (HKA) X-rays of the lower limb in both groups using a convention > 180 degrees for valgus alignment and < 180 degrees for varus alignment. For the PSI group, the mean (± SD) pre-operative HKA angle was 172.09 degrees varus (± 6.69 degrees) with a maximum varus alignment of 21.5 degrees (HKA 158.5) and a maximum valgus alignment of 14.0 degrees. The mean post-operative HKA was 179.43 degrees varus (± 2.32 degrees) with a maximum varus alignment of seven degrees and a maximum valgus alignment of six degrees. There has been a weak correlation among the values of the pre- and postoperative HKA angle. The adjusted odds ratio (aOR) of postoperative alignment outside the range of 180 ± 3 degrees was significantly higher with a preoperative varus misalignment of 15 degrees or more (aOR: 4.18; 95% confidence interval: 1.35–12.96; p = 0.013). In the control group (conventional instrumentation), this loss of accuracy occurs with preoperative misalignment of 10 degrees. Preoperative misalignment below 15 degrees appears to present minimal influence on postoperative alignment when a CT-based PSI system is used. The CT-based PSI tends to lose accuracy with preoperative varus misalignment over 15 degrees.

Synthesis and Evaluation of Levulinic Ester as Biodiesel Additives

2020 ◽  
Vol 71 (8) ◽  
pp. 21-26
Author(s):  
Elena-Emilia Oprescu ◽  
Cristina-Emanuela Enascuta ◽  
Elena Radu ◽  
Vasile Lavric
Keyword(s):  
Maximum Yield ◽  
Strength Distribution ◽  
Point Of View ◽  
Reaction Parameters ◽  
X Ray ◽  
Ethyl Levulinate ◽  
Ft Ir ◽  
Ir Analysis ◽  
Biodiesel Blend ◽  
Acid Strength Distribution

In this study, the SO42-/TiO2-La2O3-Fe2O3 catalyst was prepared and tested in the conversion of fructose to ethyl levulinate . The catalyst was characterized from the point of view of the textural analysis, FT-IR analysis, acid strength distribution, X-ray powder diffraction and pyridine adsorption IR spectra. The influence of the reaction parameters on the ethyl levulinate yield was study. The maximum yield of 37.95% in levulinate esters was obtained at 180 �C, 2 g catalyst and 4 h reaction time. The effect of ethyl levulinate addition to diesel-biodiesel blend in different rates, i.e, 0.5, 1, 2.5, 5 (w.t %) on density, kinematic viscosity and flash point was evaluated and compared with the European specification.

Formulation, Optimization,and Ex-Vivo Evaluation of Novel Lipid Carriers for Enhanced Transdermal Delivery of Hydroquinone

2020 ◽  
Vol 12 ◽  
Author(s):  
Shivani Verma ◽  
Sukhjinder Kaur ◽  
Lalit Kumar
Keyword(s):  
Ex Vivo ◽  
Skin Permeation ◽  
Topical Delivery ◽  
Gelling Agent ◽  
Minimum Size ◽  
Prolonged Release ◽  
Freeze Dried ◽  
Ft Ir ◽  
Ir Analysis ◽  
Skin Retention

Background: HQ is used for hyper-pigmentation treatment using conventional creams and gels. These formulations show various disadvantages like poor skin permeation, allergic reactions, and repeated use decreasing patient compliance. Objectives: The present work involved formulation, statistical optimization, and characterization of nanostructured lipid carriers (NLCs) for efficient topical delivery of hydroquinone (HQ) for hyperpigmentation treatment. Methods: The NLCs were optimized exploring Box–Behnken design (BBD) using three independent variables and two dependent variables. Formulation having the minimum size and maximum drug entrapment was considered as optimized formulation. Optimized formulation was evaluated for drug release followed by its freeze-drying. The freeze-dried formulation was subjected to differential scanning calorimetry (DSC) analysis, X-raydiffraction (XRD) analysis, and Fourier transform-infrared spectroscopy (FT-IR) analysis. Furthermore, NLCs based gel was prepared by using Carbopol 934 as a gelling agent. NLCs based gel was evaluated for skin permeation, skin retention, and skin distribution (through confocal microscopic analysis) using pig ear skin. Results: Optimized NLCs showed smaller particle size [(271.9 ± 9) nm], high drug entrapment [(66.4 ± 1.2) %], tolerable polydispersity index (PDI) (0.221 ± 0.012), and zeta potential [(-25.9± 1.2) mV]. The FT-IR analysis revealed excellent compatibility between HQ and other excipients. The Carbopol 934 gel containing NLCs showed high transdermal flux [(163 ± 16.2) μg/cm2/h], permeability coefficient (0.0326 ± 0.0016), and skin permeation enhancement ratio (3.7 ± 0.4) compared to marketed cream of HQ. The results of confocal microscopic (CLSM) analysis revealed the accumulation of optimized NLCs in the lower epidermal layers of skin. Conclusion: NLCs based gel was considered effective in the topical delivery of HQ to treat hyper-pigmentation due high skin permeation, skin retention, and prolonged release of HQ.

scholarly journals Integration of Dental Implants in Conjunction with EDTA-Conditioned Dentin Grafts: An Experimental Study

2021 ◽  
Vol 9 (6) ◽  
pp. 63
Author(s):  
Payam Farzad ◽  
Ted Lundgren ◽  
Adel Al-Asfour ◽  
Lars Andersson ◽  
Christer Dahlin
Keyword(s):  
Direct Contact ◽  
Mineral Content ◽  
X Rays ◽  
X Ray ◽  
Dentin Surface ◽  
Significant Difference ◽  
C And N ◽  
Micro Implants ◽  
Demineralized Dentin

This study was undertaken to investigate the integration of titanium micro-implants installed in conjunction with previously dentin-grafted areas and to study the morphological appearance, mineral content, and healing pattern of xenogenic EDTA-conditioned dentin blocks and granules grafted to cavities in the tibial bone of rabbits. Demineralized and non-demineralized dentin blocks and granules from human premolars were implanted into cavities prepared on the lateral aspects of the tibias of rabbits. After a healing period of six months, micro-implants were installed at each surgical site. Histological examinations were carried out after 24 weeks. Characterization of the EDTA-conditioned dentin blocks was performed by means of light microscopy, dental X-rays, scanning electron microscopy, and energy dispersive X-ray analysis (EDX). No implants were found to be integrated in direct contact with the dentin particles or blocks. On the EDTA-conditioned dentin surface, the organic marker elements C and N dominated, as revealed by EDX. The hydroxyapatite constituents Ca and P were almost absent on the dentin surface. No statistically significant difference was observed between the EDTA-conditioned and non-demineralized dentin, as revealed by BIC and BA. The bone-inductive capacity of the dentin material seemed limited, although demineralization by means of EDTA indicated higher BIC and BA values in conjunction with the installed implants in the area. A 12 h EDTA treatment did not fully decalcify the grafts, as revealed by X-ray analysis.

scholarly journals POS0016 THE EVALUATION OF FUNCTIONAL ABILITIES OF PATIENTS WITH OSTEOPOROTIC VERTEBRAL FRACTURES AS A BASIS FOR REHABILITATION PROGRAMS DEVELOPING

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 209.2-210
Author(s):  
L. Marchenkova ◽  
V. Vasileva ◽  
M. Eryomushkin
Keyword(s):  
Muscle Strength ◽  
Vertebral Fractures ◽  
Trunk Muscles ◽  
Control Group ◽  
Study Group ◽  
Primary Osteoporosis ◽  
X Rays ◽  
Functional Abilities ◽  
Rehabilitation Programs ◽  
Osteoporotic Vertebral Fractures

Background:Due to the demand for special rehabilitation programs for patients with osteoporotic vertebral fractures (VFs), it is of interest to study the functional abilities of those patients. The scientific hypothesis suggests that osteoporotic VFs would cause muscle weakness, muscle dysfunction and conditional disturbances.Objectives:to estimate muscle strength, motor function and coordination disorders in patients with VFs in the setting of systemic osteoporosis as a basis for rehabilitation programs developing.Methods:120 patients aged 43−80 with primary osteoporosis were enrolled. Study group comprised of 60 subjects (56 women, 4 men) with at least 1 VF confirmed by X-rays. Control group included 60 subjects (56 women, 4 men) with osteoporosis but without any osteoporotic fracture. The examination program included back muscles tenzodynamometry, balance tests and stabilometry.Results:Muscle strength deficiency was estimated in study group in trunk flexors (TF) — 40.9% and in trunk extensors (TE) — 18.1% with an adequate function of the left lateral flexors (LLF) and in right lateral flexors (RLF). Patients with VFs had the lower muscle strength vs controls of TE (15.64±9.8 vs 27.73±9.9 kg, p=0.00002), TF (14.61±8.98 vs 21.28±8.38 kg, p=0.0006), LLF (13.10±7.2 vs 24.06±8.9 kg, p=0.005) and RLF 13.44±7.43 vs 24.26±7.65 kg, p=0.0003). Patients with VFs lose their balance faster during one-leg-standing test with open eyes (5.0 [1.0; 10.0] vs 7.5 [5.0; 10.5] sec in control group, p=0.03) and with closed eyes (2.0 [0; 3.0] vs 3.5 [3.0; 5.0] sec, p=0.04). Fukuda-Unterberger test showed greater side dislocation in study group — 40° [25; 45] vs controls 30° [10; 45], (p=0.02). According to stabilometry study group was characterized vs control group by lower balance coefficient with open eyes (77.2±7.6 vs 85.7±9.4%, p=0.002) and with closed eyes (67.1±9.8 vs 73.4±9.9%, p=0.03), greater sagittal displacement (6.8 [2.1; 37.7] vs 4.8 [1.8; 10.7] mm, p=0.025) and deviation in the saggital plane (1.2 [-1.07; 1.5] vs -1.2 [-1.5; 1.2] mm, p=0.01), and also less pressure center velocity (9.51±4.4 vs 7.1±2.7 mm/sec, р=0.009).Conclusion:Osteoporotic VFs are associated with reduction of trunk muscles strength and negatively affect static and dynamic balance function that should be taken into account when developing rehabilitation programs for these patients.Disclosure of Interests:None declared.

Impact of Chemical Modification on the Physical and Mechanical Properties of Tropical Wood Material

2012 ◽  
Vol 576 ◽  
pp. 314-317
Author(s):  
Sinin Hamdan ◽  
M. Saiful Islam
Keyword(s):  
Mechanical Properties ◽  
Diazonium Salt ◽  
Treated Wood ◽  
Coupling Reaction ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Ft Ir ◽  
Ir Analysis ◽  
D Values ◽  
Benzene Diazonium

Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.

scholarly journals Effects of Er:YAG Laser on Mineral Content of Sound Dentin in Primary Teeth

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Cigdem Guler ◽  
Meral Arslan Malkoc ◽  
Veli Alper Gorgen ◽  
Erhan Dilber ◽  
Mehmet Bulbul
Keyword(s):  
Surface Roughness ◽  
Mineral Content ◽  
Primary Teeth ◽  
Er:Yag Laser ◽  
Short Pulse ◽  
Pulse Mode ◽  
Emission Spectrometry ◽  
Control Group ◽  
Group A ◽  
Group B

The aim of the present study was to evaluate the mineral content of sound dentin in primary teeth prepared using an Er:YAG laser at two different power settings. Thirty-six primary second molars were used in this study. Three dentin slabs were obtained from each tooth, and the slabs were randomly divided into three groups: Group A, control; Group B, Er:YAG laser at 3.5 W, 175 mJ, and 20 Hz, short pulse mode; and Group C, Er:YAG laser at 4 W, 200 mJ, and 20 Hz, medium-short pulse mode. One dentin slab per group was used to evaluate the dentinal morphology and surface roughness values using SEM and profilometer, respectively. Mineral content in the dentin slabs were calculated by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The data were analyzed by one-way analysis of variance and Tukey’s HSD tests. No significant differences in Ca, K, Mg, Na, and P levels or Ca/P ratio were found among the groups(P>0.05). SEM micrographs showed that surface irregularities increased with a higher power setting. The surface roughness after laser treatment in Group B and Group C was found to be similar, unlike Group A.

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