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.
Background: Diabetes mellitus is a chronic metabolic disorder of the carbohydrate, protein and fat metabolism, resulting in increased blood glucose levels. Various complications of diabetes have been described with periodontitis being added as the sixth complication of diabetes mellitus. Matrix metalloproteinase-8 (MMP-8) has been identified as major tissue-destructive enzyme in periodontal disease. MMP-8 is released from neutrophils in a latent, inactive pro form and becomes activated during periodontal inflammation by independent and/or combined actions of host-derived inflammatory mediators .C-reactive protein is a systemic marker released during the acute phase of an inflammatory response. Subjects, materials and methods: Total samples
... Show MoreThe Evaluation of the immune response in Golden Hamsters experimentally infected with Leishmania donovani was determined in this study, particularly, the cellular immune response. Follow up has maintained to determine the Delayed Type of Hypersensitivity using skin test both in infected and control lab animals. Chicken red blood cells were used as a parameter to evaluate the immune system; they are dull and have the ability of immunization. Two concentrations of chicken R.B.C were examined to determine which gives the higher titration in Hamsters and those were 1.5 X 109 cell/ml and 3 X 109 cell/ml , the second concentration gave the maximum titration where then used in this work. After sensitization with Chicken R.B.C for both infected a
... Show MoreThe Evaluation of the immune response in Golden Hamsters experimentally infected with Leishmania donovani was determined in this study, particularly, the cellular immune response. Follow up has maintained to determine the Delayed Type of Hypersensitivity using skin test both in infected and control lab animals. Chicken red blood cells were used as a parameter to evaluate the immune system; they are dull and have the ability of immunization. Two concentrations of chicken R.B.C were examined to determine which gives the higher titration in Hamsters and those were 1.5 X 109 cell/ml and 3 X 109 cell/ml , the second concentration gave the maximum titration where then used in this work. After sensitization with Chicken R.B.C for both in
... Show MoreBackground: the aim of this study was to evaluate the effect of different surface acids treatments (37%phospjoric acid, 5%hydrofluoric acid, 1.23 acidulated phosphate fluoride) of feldspathic ceramic VITA 3D MASTER , and the effect of thermocycling on shear bond strength using a ceramic repair kit (ivoclar/vivadent). Material and Methods: sixty Nickel-Chromium metal base plates were prepared(9mm diameter,3mm depth) using lost wax technique, 2mm thick layer of ceramic(VITA 3D MASTER) fused to metal plates, all specimens were embedded in acrylic resin blocks except their examined surfaces and divided into 3 main groups 20 specimens each, Grp A: treatment with 37%phosphoric acid for 2 mins, Grp B: etching with 5% hydrofluoric acid for 2mins,
... Show Moreتضاعف انتشار مرض السكري من النوع 2 في السنوات الأخيرة نتيجة الخلل في إنتاج الأنسولين ، والذي يمكن أن يتطور ليشكل مضاعفات مرض السكري التي تؤثر على الكلى والأعصاب والعينين. ونتيجة لذلك ، فإن التشخيص المبكر والتصنيف لمرض السكري من النوع الثاني ضروريان لمساعدة الطبيب على التقييم. وفقًا لذلك ، هدفت الدراسة الحالية إلى تحديد مستويات بروتين ارتباط الريتينول 4 (RBP4) في المرضى الذين يعانون من السكري النوع الثاني وم
... Show MoreIn the present work, different thicknesses of CdS film were prepared by chemical bath deposition. Z-Scan technique was used to study the nonlinear refractive index and nonlinear absorption coefficients. Linear optical testing were done such as transmission test, and thickness of films were done by the interference fringes (Michelson interferometer). Z-scan experiment was performed at 650nm using CW diode laser and at 532nm wavelength. The results show the effect of self-focusing and defocusing that corresponds with nonlinear refraction n2. The effect of two-photon absorption was also studied, which correspond to the nonlinear absorption coefficient B.
In the present study, the effect of Zinc nanoparticles on levels of (T3 , T4 and TSH) hormones was investigated. Zinc nanoparticles were synthesized by Laser induced plasma.The Nd: YAG Nd: YAG laser with a wavelength of 1064 nm was used to generate nanomaterials of the elements (zinc) upon collision with target atoms. Plasma generated by different laser intensity is generated. After confirming the preparation of zinc nanoparticles, XRD, AFM was examined, and the effect of these substances on the thyroid gland (T3, T4, TSH) was observed for two doses of each component (1 ml / kg, 4 ml / kg) after conducting a cytotoxicity examination of the lymphocytes of the rats extracted from Rat spleen was 1.8% less toxic to zinc, and as noted The
... Show MoreIntroduction: The present study was performed to evaluate the influence of a 1064 nm fiber laser on shear bond strength (SBS) at the interface of titanium and resin cement. Methods: Forty titanium discs of 6 mm × 3 mm (diameter and thickness respectively) were categorized into four groups (n=10): control group without any surface treatment and three groups treated with a fiber laser with 81 ns pulse duration, 30 kHz frequency, 10000 mm/s scanning speed, 0.05 mm spot size, and different average power values (3, 5 and 7 W) depending on the tested group. Titanium disc characterization was performed by the scanning electron microscope (SEM) and surface roughness tester. Phase analysis was achieved using an X-ray diffractometer (XRD). F
... Show More