Background: Separation and deboning of artificial teeth from denture bases present a major clinical and labortory problem which affect both the patient and the dentist. The optimal bond strength of artificial teeth with denture base reinforced with nanofillers and flexible denture bases and the effect of thermo cycling should be evaluated. This study was conducted to evaluate and compare the shear bond strength of artificial teeth (acrylic and porcelain) with denture bases reinforced by 5% Zirconium oxide nanofillers and flexible bases under the effect of different surface treatments and thermo cycling and comparing the results with conventional water bath cured denture bases. Material and methods: Two types of artificial teeth; acrylic and porcelain were used and prepared for this study. Five specimens of each tooth type were processed to each denture base materials after the application of different surface treatments; these teeth were bonded to heat polymerized, nano composite resin and flexible denture bases. Specimens were thermo cycled and tested for bond strength until fracture with an Instron universal testing machine. Data were analyzed with analysis of variance and student T-test. Photomicrographic examinations were used to identify adhesive and cohesive failures within debonded specimens. Results: The mean force required to fracture the specimens were obviously larger for nanocomposite specimens compared with the heat cured and flexible specimens. The most common failure was cohesive within the tooth or the denture base. With each base material, the artificial teeth which were treated with thinner exhibited highest shear bond strength. Thermocycling had deleterious effect on the flexible denture base specimens. In general, nanocomposite and heat cured groups failed cohesively within the artificial tooth. While the valplastic groups failed adhesively at the tooth denture base interface. Conclusions: Within the limitations of this study, the type of denture base materials and surface treatments of the tooth selected for use may influence the shear bond strength of the tooth to the base. Selection of more compatible combinations of base and artificial teeth may reduce the number of prosthesis fractures and resultant repairs. Key words: acrylic teeth, porcelain teeth, Nano composite denture base, thermo cycling, flexible denture, thinner,
Background: Dialysis is in common use to treat patients
with end stage renal failure .However longstanding dialysis
harboring some cellular changes in various body fluids.
This study was conducted in order to detect these changes
in urine.
Objective: The study was conducted to detect cellular
changes in urine of patients with longstanding dialysis.
Method: Fifty-three urine samples were examined
cytologically obtained from patients with longstanding
dialysis during 6 months period. Freshly voided midstream
urine samples were taken . Samples were centrifuged and 2
to 3 drops of sediments were smeared on 2 glass slides and
fixed in 95% ethyl alcohol then stained with Hand E stain
to be evaluated.
R
Background:
Background: Changes in the indication for splenectomy in hematology, especially in hematological malignancies, has been observed in the last 10 – 15 years. Yet splenectomy, as a diagnostic tool, is still an option in the management of isolated splenomegaly.
Objectives: to describe the outcome of diagnostic splenectomy in the management of 12 patients presenting with isolated splenomegaly.
Patients and methods: Between August 2005 and July2012, Twelve patients underwent splenectomy for diagnostic purposes in the hematology unit / Baghdad Teaching Hospital. Analysis of these patients was done with a median follow up of 16 months (6 months -4 years).
Results: The median age was 46 years (range 25-68). The median duration of sympt
In this paper , certain subclass of harmonic multivalent function defined in the exterior of the unit disk by used generalize hypergeometric functions is introduced . In This study an attempting have been made to investigate several geometric properties such as coefficient property , growth bounds , extreme points , convolution property , and convex linear combination .
Due to the vast using of digital images and the fast evolution in computer science and especially the using of images in the social network.This lead to focus on securing these images and protect it against attackers, many techniques are proposed to achieve this goal. In this paper we proposed a new chaotic method to enhance AES (Advanced Encryption Standards) by eliminating Mix-Columns transformation to reduce time consuming and using palmprint biometric and Lorenz chaotic system to enhance authentication and security of the image, by using chaotic system that adds more sensitivity to the encryption system and authentication for the system.
In this work, we consider a modification of the Lotka-Volterra food chain model of three species, each of them is growing logistically. We found that the model has eight equilibrium points, four of them always exist, while the rest exist under certain conditions. In terms of stability, we found that the system has five unstable equilibrium points, while the rest points are locally asymptotically stable under certain satisfying conditions. Finally, we provide an example to support the theoretical results.
Background: Zinc is involved in a variety of
metabolic processes and it has a well known
antioxidant activity, so the measurement of its serum
level can have a special value in several diseases.
Objectives: The study is designed to determine the
serum zinc level in heart failure patients and to
compare it with that of healthy individuals and to
study the significance of the results obtained.
Methods: Atomic absorption spectrometer
technique was used to determine serum zinc level in
fifty heart failure patients and fifty healthy individuals
who were age and sex matched.
Results: The mean serum zinc level in healthy
individuals was about 45.5% greater than that of heart
failure patients. This diffe
Background: Infectious mononucleosis (IM) is a lymphoproliferative disease caused primarily by the Epstein-Barr virus (EBV) infection. The initial viral infection by EBV occurs in B lymphocytes and is followed by an extensive proliferation of T lymphocytes. Previous studies on immunity to EBV (including IM) have mainly focused on activation of peripheral blood T cells, which are responsible for the lymphocytosis in blood during acute IM.
Patients and Methods: Indirect immunofluorescence technique analysis was performed to detect the percentage of CD3, CD4, CD8, CD19, and CD56 positive lymphocytes.
Results: Our results on the phenotype of T cells in samples from patients with infectious mononucleosis sh
Many fuzzy clustering are based on within-cluster scatter with a compactness measure , but in this paper explaining new fuzzy clustering method which depend on within-cluster scatter with a compactness measure and between-cluster scatter with a separation measure called the fuzzy compactness and separation (FCS). The fuzzy linear discriminant analysis (FLDA) based on within-cluster scatter matrix and between-cluster scatter matrix . Then two fuzzy scattering matrices in the objective function assure the compactness between data elements and cluster centers .To test the optimal number of clusters using validation clustering method is discuss .After that an illustrate example are applied.
Background: Cerebral ischemia associated with Antiphospholipid Syndrome(APS) is a common arterial manifestation in adults.
Objectives: To look for the frequency of Antiphospholipid Antibodies (aPL), and their relation with other risk factors in young patients with cerebral ischemia.
Patients and methods: A retrospective study of 40 young patient’s ≤ 50 years with stroke collected from medical and neurological wards of Baghdad Teaching Hospital (BTH) from January - December 2009. All were inquired about the presence of risk factors of stroke, and sent for aPL including Anticardiolipin (ACL) and Lupus Anticoagulant (LA).
Results: Eight (20%) had ACL. Nine (22.5%) had LA. Both were present in 6(15%). ACL and/or LA were present