Preferred Language
Articles
/
ijl-230
Pulsed Er,Cr:YSGG Laser For Surface Modification of Dental Zerconia Ceramic
...Show More Authors

Background: Surface treatment of machined dental zirconia for enhancement of the adhesion to resin cement, using Er,Cr:YSGG  Laser. Materials and Methods: Total number of 42 zirconia disc specimens (9 mm diameter, and 2 mm height) was sintered according to the manufacturer instruction. They are divided into six groups, each group of seven samples. Laser groups (Experiment parameters) were depend on laser total irradiation time, pulse duration, and power. Group (A): 20 sec., 60 µs pulse duration. Group (B): 30 sec., 60 µs pulse duration. Group (C): 40 sec., 60 µs pulse duration. Group (D): 20 sec., 700 µs pulse duration. Group (E): 30 sec., 700 µs pulse duration, with different powers used (1, 1.50, 2, 2.50, 3, 3.50, 4) W. And finally group (N): untreated samples representing the control group. Luting cement was applied to laser treated zirconia sample’s surfaces and cured by light for 40 s. Then all sample surfaces were examined under a stereo microscope, for determining the depth mean values of the created pulse holes, for each specimen. The bond between the laser treated zirconia surfaces and the applied resin cement, were examined for all samples by using a universal testing machine, for determination of the shear bond strength values. Six additional specimens: one untreated sample and five other samples that were laser irradiated with the parameters that exhibited the highest shear bond strength values in each treated group, were examined for their average surface roughness by using an atomic force microscope. Another similar six specimens were also examined for their surface morphology, by using a scanning electron microscope. Both surface examination methods were performed by specialized operators. The bond failure modes were also examined by an optical microscope. Results obtained from shear bond strength test and laser pulse depth examination were statistically analyzed. Results: There was significant differences in the shear bond strength values, indicating a clear increase in zirconia-resin cement bonding, especially in group B (30 s, 60 µs, 4W), reaching  (8.63 Mpa). Whereas, the control group had (4.49 Mpa), and an enhanced zirconia surface average roughness, that group E (30 s, 700 µs, 3.5 W) specimen had the highest value (14.5nm), among the six examined specimens. While the control specimen had the least value examined which is (3.05nm). Conclusion: A relation between the cement bonding efficiency and the laser treated zirconia surface roughness, laser pulse depths was detected. The Er,Cr:YSGG laser pulse duration and  power is  crucial parameters in the surface roughness enhancement of the zirconia ceramic.

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Sep 14 2016
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of Mouth Rinses on Surface Roughness of Two Methacrylate-Based and Siloraine-Based Composite Resins
...Show More Authors

Background: Various fluids in the oral environment can affect the surface roughness of resin composites. This in vitro study was conducted to determine the influence of the mouth rinses on surface roughness of two methacrylate-based resin (nanofilled and packable composite) and siloraine-based resin composites.

Materials and methods: Disc-shaped specimens (12 mm in diameter and 2mm in height) were prepared from three types of composi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Sep 01 2019
Journal Name
Baghdad Science Journal
Studies on Surface Morphology and Electrical Conductivity of PS Thin Films in Presence of Divalent Complexes
...Show More Authors

       Optical properties and surface morphology of pure and doped Polystyrene films with different divalent metals of Zn, Cu and Sn and one concentration percentage have been studied. Measurements of UV-Vis spectrophotometer and AFM spectroscopy were determined. The absorbance, transmittance and reflectance spectrums were used to study different optical parameters such as absorption coefficient, refractive index, extinction coefficient and energy gap in the wavelengths rang 200-800nm. These parameters have increased in the presence of the metals. The change in the calculated values of energy gaps with doping metals content has been investigated in terms of PS matrix structural modification. The value of opt

... Show More
View Publication Preview PDF
Scopus (10)
Crossref (8)
Scopus Clarivate Crossref
Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Gas sensitivity properties of TiO2/Ag nanocomposite films prepared by pulse laser deposition
...Show More Authors

In this study, a double frequency Q-switching Nd:YAG laser beam (1064 nm and λ= 532 nm, repetition rate 6 Hz and the pulse duration 10ns) have been used, to deposit TiO2 pure and nanocomposites thin films with noble metal (Ag) at various concentration ratios of (0, 10, 20, 30, 40 and 50 wt.%) on glass and p-Si wafer (111) substrates using Pulse Laser Deposition (PLD) technique. Many growth parameters have been considered to specify the optimum condition, namely substrate temperature (300˚C), oxygen pressure (2.8×10-4 mbar), laser energy (700) mJ and the number of laser shots was 400 pulses with thickness of about 170 nm. The surface morphology of the thin films has been studied by using atomic force microscopes (AFM). The Root Mean Sq

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Laser
Effects of Ho: YAG Laser (2100nm) in Prostate Tissue: An in vitro Study
...Show More Authors

Benign prostate hyperplasia (BPH), non-cancerous enlargement of prostate, is the most prevalent disease entity in elderly men. BPH affects 40% of men after the age of 60year worldwide. BPH causes problems for patients with significant lower urinary tract obstructive symptoms, if not responding to medical therapy, surgical intervention is instituted. One method of the treatment of symptomatic BPH is laser prostatectomy. The understanding of tissue effects by laser radiation is very important for the safe clinical application of laser. Objective: study the 2100 nm Ho: YAG laser gross tissue effects in the prostate at different laser dose settings in an vitro model prostate tissue samples harvested from same specimen of open surgery prostat

... Show More
View Publication Preview PDF
Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Laser
PDF Mechanical Properties of AISI 316L Stainless Steel Produced Via Selective Laser Melting
...Show More Authors

Abstract Additive manufacturing has been recently emerged as an adaptable production process that can fundamentally affect traditional manufacturing in the future. Due to its manufacturing strategy, selective laser melting (SLM) is suitable for complicated configurations. Investigating the potential effects of scanning speed and laser power on the porosity, corrosion resistance and hardness of AISI 316L stainless steel produced by SLM is the goal of this work. When compared to rolled stainless steel, the improvement is noticeable. To examine the microstructure of the samples, the optical microscopy (OM), scanning electron microscopy (SEM), and EDX have been utilized. Hardness and tensile strength were us

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 15 2004
Journal Name
Iraqi Journal Of Laser
Interstitial Photocoagulation of Low Anal Fistula using 810 nm Diode Laser: Prospective Study
...Show More Authors

Many conservative sphincter-preserving procedures had been described to be effective in
healing of anal fistula without excision or de roofing.
Objective: To verify the outcome of mere photocoagulation of the fistula tract on healing of low anal
fistula.
Materials and Methods: Using 810nm diode laser, the tracts of low anal fistulae in a cohorts of six male
patients (mean age of 32 yr) had been photocoagulated by retrograde application of laser light through an
orb tip optical fiber threaded in to the tract. Swabs for culture and sensitivity testing were obtained before
and after laser application. Patients were followed up regularly to announce fistula healing.
Results: Mean laser exposure time was 6.6 min., mean

... Show More
View Publication Preview PDF
Publication Date
Sat Oct 01 2022
Journal Name
International Journal Of Nanoscience
Preparation and Physical Properties of Mg-Zn Nano-crystal by Laser-induced Plasma
...Show More Authors

To learn how the manner of preparation influences film development, this study examined film expansion under a variety of deposition settings. To learn about the membrane’s properties and to ascertain the optimal pretreatment conditions, which are represented by ambient temperature and pressure, Laser pressure of 2.5[Formula: see text]m bar, the laser energy density of 500[Formula: see text]mJ, distortion ratio ([Formula: see text]) as a function of laser pulse count, all achieved with the double-frequency Nd: YAG laser operating in quality-factor mode at 1064[Formula: see text]nm. MgxZn[Formula: see text] films of thickness [Formula: see text][Formula: see text]nm were deposited on glass substrates at pulse

... Show More
View Publication
Scopus (2)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Fri Jan 11 2019
Journal Name
Iraqi Journal Of Physics
Characterization of smoker and non smoker human teeth using laser induced breakdown spectroscopy
...Show More Authors

In this work, the elemental constituents of smoker and nonsmoker
teeth samples of human were analyzed by Laser induced breakdown
spectroscopy method (LIBS). Many elements have been detected in
the healthy teeth samples, the important once are Ca, P, Mg, Fe, Pb
and Na. Many differences were found between (female and male)
teeth in Ca, P, Mg, Na and Pb contents. The concentrations of most
toxic elements were found significantly in the smoker group. The
maximum concentrations of toxic elements such as Pb, Cd and Co
were found in older male age above 60 year. Also, it was found that
the minimum concentrations of trace elements such as Ca, P and Na
exist in this age group. From these results it is clear that the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Dec 10 2007
Journal Name
Iraqi Journal Of Laser
Combination Effect of Laser, Antibiotics and Different Temperature on Locally Isolated Pseudomonas aeruginosa
...Show More Authors

In humans, Pseudomonas aeruginosa is the second most frequent gram negative nosocomial pathogen in hospitals and has the highest case-fatality rate of all hospital-acquired bacteremia because of the hardy resistance of these bacteria to mechanical cleansing as well as to disinfectant, and many antibiotics. The susceptibility of bacteria against the antibiotics is modulated by several local factors such as temperature which modified drug efficacy, so this study was carried out to evaluate the effect of different temperature (20,42,45)Ċon the susceptibility of Pseudomonas aeruginosa to the minimum inhibitory concentrations (MIC) of the antimicrobial agents before and after irradiation. The samples collected from 150 persons suffering from

... Show More
View Publication Preview PDF
Publication Date
Tue Oct 08 2002
Journal Name
Iraqi Journal Of Laser
Cross-focusing Effect of Two Intense Laser Beams on Electron Plasma Wave Excitation
...Show More Authors

This paper presents the effect of relativistic and ponderomotive nonlinearity on cross-focusing of two intense laser beams in a collisionless and unmagnetized plasma. It should be noted here that while considering the self-focusing due to relativistic electron mass variation, the electron ponderomotive density depression in the channel may also be important. Therefore/these two nonlinearties may simultaneously affect the self-focusing process. These nonlinearities depend not only on the intensity of one laser but also on the second laser. Therefore, one laser beam affects the dynamics of the second beam and hence the process of cross-focusing takes place. The electric field amplitude of the excited electron plasma wave (EPW) has been cal

... Show More
View Publication Preview PDF