Abstract: The use of indirect, all-ceramic restorations has grown in popularity among dentists. Studies have demonstrated that for indirect ceramic restorations to be effective over time, cement and ceramic must be bonded in a stable manner. Chemical, mechanical, and laser irradiation are among the methods used to precondition ceramic surfaces in order to increase bond strength.The objective of the study: This study was performed to investigate the roughness values and surface topography of lithium disilicate glass-ceramic treated with conventional methods and different Er,Cr:YSGG, and fractional CO2 laser conditioning parameters.Material and methods: Sixty samples of lithium disilicate glass-ceramic were divided as follows: 1- (n = 10) untreated; 2- (n = 10) Hydrofluoric acid etched; 3- (n = 10) conditioned by Er,Cr: YSGG laser at (7 W, 25 Hz, 50/50% Water/Air, pulse duration 60 us, irradiation time 2 min); 4- (n = 10) conditioned by Er,Cr:YSGG laser at (5 W, 25 Hz, 50/50% Water/Air, pulse duration 60 us, irradiation time 2 min); 5- (n = 10) conditioned by fractional CO2 laser at (power 8 W, pulse duration 10 ms); 6- (n = 10) conditioned by fractional CO2 laser at (power 6 W, pulse duration 10 ms). Then evaluated by: Profilometer, and scanning electron microscopy.Results: The highest roughness values were found in CO2 laser power 8 W treated samples, followed by Er,Cr:YSGG laser power 7W treated samples. The hydrofluoric acid-etched samples showed roughness values comparable to those of CO2 laser-irradiated samples with a power of 6 W. The untreated sample showed the smoothest surface with the lowest roughness value.Conclusion: The application of Er,Cr:YSGG, fractional CO2 lasers enhances the surface roughness of lithium disilicate samples positively, showing the promised results of using these parameters in bonding procedures.
This work aimed to prepare and study the characteristic feature of lead nanoparticles (PbNPS) and follow its effects on some physiological aspects in rats.PbNPS was prepared by laser ablation of pure lead mass with a pulse of 500 and 100 mJ of energy. The results indicated that the wavelength was approximately 196 and the concentration was reported at 53,8967 mg / L. AFM, as the average diameter has been estimated at 69.93 nm. EFSEM shows the spherical shape of the particle.The experimental animals (rats) were divided into two groups, with seven rats for each one. The first group was a control and the second group was injected with 1 milliliter of PbNPS (53.8673 mg/l) per day for 45 days. Bioaccumulated lead ( in liver, spleen kidney and
... Show MoreIn this work, the dyes Rhodamine B and Coumarin 102 containing titanium dioxide nanoparticles were used as scattering centers to fabricate a random gain medium. The laser dye was dissolved in hexanol and methanol solvent respectively. The titanium dioxide nanoparticles were synthesized by DC reaction magnetron spraying technique. The random-gain medium was made by adding 2.5 mg of titanium dioxide nanoparticles to Rhodamine and coumarin 102 dyes by coating the glass cell with two-sided titanium dioxide with high spectral efficiency and low production cost. A narrow line optical emission was detected at 565 nm for Rhodamine B and 534 nm for coumarin 102, where it was found that rhodamine B dye has FWHM 8 nm and coumarin dye 102 has FWHM 9 nm
... Show MoreThe propagation of laser beam in the underdense deuterium plasma has been studied via computer simulation using the fluid model. An appropriate computer code “HEATER” has been modified and is used for this purpose. The propagation is taken to be in a cylindrical symmetric medium. Different laser wavelengths (1 = 10.6 m, 2 = 1.06 m, and 3 = 0.53 m) with a Gaussian pulse type and 15 ns pulse widths have been considered. Absorption energy and laser flux have been calculated for different plasma and laser parameters. The absorbed laser energy showed maximum for = 0.53 m. This high absorbitivity was inferred to the effect of the pondermotive force.
In this study, silver nanoparticles (AgNPs) were synthesized using a cold plasma technique and a plasma jet. They were then used to explore how photothermal treatment may be used to treat lung cancer (A549) and normal cells (REF) <i>in vitro</i>. The anti-proliferative activity of these nanoparticles was studied after A549 cells were treated with (AgNPs) at various concentrations (100%, 50%, or 25%) and exposure times (6 or 8 min) of laser after 1 h or 24 h from exposed AgNPs. The highest growth inhibition for cancer cells is (75%) at (AgNPs) concentration (100%) and the period of exposure to the laser is (8 min). Particle size for the prepared samples varied according to the diameter o
... Show MoreThe rapid developmemt of information technology and its use in all fields has a bositive influence on all fields , and financial markets have a share of this development through the use of an electronic trading system to settle transactions and enhance transparency and disclosure in all activities of these markets and stimulate their performance .
It is worth nothing that these revolutions remove the necessity for nonstop connection with persons through the internet or phone networks , novel knowledge decreases the charges of structure original transaction system and reducing the fences of new participants entry .
The development in transportations expertise allows for quicker or
... Show MoreAbortion is a condition that occurs due to one of the pathological injuries, often one of the members of the TORCH is the real cause. The current study aimed to investigate the impact of toxoplasmosis, HSV-2 infections with abortion, and also, the identification of immunogenetics marker (interleukin-10) that may be associated with abortion. Anti-Toxoplasma IgG, IgM, Herpes simplex virus-2 IgM, human soluble leukocyte antigen class I–G and interleukin10 were estimated by ELISA technique, while the expression of IL-10 gene was investigated by using the real-time PCR. The results showed that among aborted women the rate of anti-Toxoplasma and HSV-2 IgM antibodies occurred within the age groups (21–30) years and (31–40) years 32(100.0%) a
... Show MoreThe performance evaluation process requires a set of criteria and for the purpose of measuring the level of performance achieved by the Unit and the actual level of development of its activities, and in view of the changes and of rapid and continuous variables surrounding the Performance is a reflection of the unit's ability to achieve its objectives, as these units are designed to achieve the objectives of exploiting a range of economic resources available to it, and the performance evaluation process is a form of censorship, focusing on the analysis of the results obtained from the achievement All its activities with a view to determining the extent to which the Unit has achieved its objectives using the resources available to it and h
... Show MoreIn this research the performance of 5G mobile system is evaluated through the Ergodic capacity metric. Today, in any wireless communication system, many parameters have a significant role on system performance. Three main parameters are of concern here; the source power, number of antennas, and transmitter-receiver distance. User equipment’s (UEs) with equal and non-equal powers are used to evaluate the system performance in addition to using different antenna techniques to demonstrate the differences between SISO, MIMO, and massive MIMO. Using two mobile stations (MS) with different distances from the base station (BS), resulted in showing how using massive MIMO system will improve the performance than the standar
... Show MoreMany trials were made to prepare Tinidazole 2% as bioadhesive vaginal gels using different gel bases including hydroxypropyl methyl cellulose (3 and 4% w/w), methylcellulose (3 and 4%w/w) and carboxymethylcellulose (2 and 3% w/w) .Swelling index of the polymers,pH , viscosity , bioadhesive force , and in-vitro drug release to the simulating vaginal fluid (S.V.F.) were investigated for all the prepared bioadhesive gels . The mechanism of drug release from the gel bases was also investigated.
The results revealed that C MC 3% gave the highest viscosity and bioadhesive strength with the lowest release rate while lowest viscosity and bioadhesive force
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