Background: Acrylic resin polymer s used in prosthodontic treatment as a denture base material for several decades. Separation and debonding of artificial teeth from denture bases present a laboratory and clinical problem affect patient and dentist. The aim of this study is to evaluate the effect of oxygen plasma and argon plasma treatment of acrylic teeth and thermocycling on bonding strength to hot cured acrylic resin denture base material. Materials and Methods: Sixty denture teeth (right maxillary central incisor) are selected. The denture teeth are waxed onto the beveled surface of rectangular wax block according to Japanese standard for artificial teeth. The control group consisted of 20 denture teeth specimen without any treatment. The oxygen plasma group consisted of 20 denture teeth specimen treated with oxygen plasma for two minutes exposure time at plasma apparatus. The argon plasma group consisted of 20 denture teeth treated with argon plasma for two minuets exposure time. All the specimens are undergone flasking and wax elimination procedure in the conventional way. All specimens stored in distilled water for 7 days at 37°C, then half of the specimens of all groups undergoes thermocycling between 5°C -55°C in 60 seconds cycles for three days and tested for shear bond strength using universal testing machine the data was collected and analyzed statistically using analysis of variance and independent sample t-test. Results: The plasma treated groups showed the higher mean force required to fracture the acrylic teeth from their heat cured acrylic resin denture bases, as compared to control group, and the oxygen plasma treatment group showed higher shear bond value than the argon plasma treatment. The thermocycling had a deleterious effect on bonding strength for control group while the plasma treated group showed an increase in bond strength following thermocycling. Conclusion: Plasma treatment method was an effective approach for increasing the shear bond strength as a result of surface oxidation and chemical etching effect of oxygen plasma and micromechanical interlocking effect of argon plasma.
The sintering behavior of Alumina was investigated by adding TiO2. The addition of TiO2 lowered the sintering temperature of the Alumina compared with those of pure Alumina. The result suggests that TiO2 acts as an activator for sintering of Alumina. Water absorption, apparent porosity and density were examined for both pure and TiO2 added to Alumina samples. The variations of sintering behavior were discussed in terms of shrinkage, porosity, water absorption and density. Thermal shock resistance was also examined. In term of this work, the way of improving the thermal shock resistance in oxide- based materials by adding reactive Titania powder to the Alumina samples. The laboratory results showed an improvement in thermal shock resistance
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This study sought to determine malformation caused by Ochratoxin-A (OTA) on mouse embryos. Twenty adult female white Swiss mice (mus msculus) were divided into four groups, with five females per group, and with one male placed with two females in a cage. Avaginal plug was observed in the early morning and the day of mating was considered as day of pregnancy followed by the first day of pregnancy. Three sub lethal concentrations of OTA were applied to the respective groups (other than the control), 1mg/kg, 2mg/kg and 4mg/kg. The animals were given 0.1 ml per 10 gm body weight per concentration of OTA once a day during days 7-14 of pregnancy. The control group animals were given distilled water. The pregnant mice were dissected, and the embry
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Background: Prelabour rupture of membranes is a problem that faces the obstetricians. It has many maternal and fetal sequale and its etiology and management still controversial.
Objective: To test the absolute nucleated red blood cells counts at birth in infants who are born after prelabour rupture of membranes.
Methods: A prospective study conducted in AL-Kadhymia Teaching Hospital. Hundred pregnant women were included in this study. Fifty pregnant women who had prelabour rupture of membranes considered as group (1), other fifty pregnant women with intact membranes considered as group (2) through a period of one year. Nucleated red blood cell counts of venous cord blood obtained within one hour of life from 50 infants who we
Objective: To evaluate the effect of mouth rinses (Biofresh and ZAK) on the surface micro hardness
of two light cure restorative material (Tetric ceram ivoclar-vivadent) and (3M Z 250) dental
composite.
Methodology: The microhardness values of (sixty) composite specimens were measured at the top
surfaces after 24 hours of immersion in different solutions (Biofresh, Zak mouth wash and distilled
water as control). Comparison done using descriptive statistics (mean, SD, SEM, minimum and
maximum values) and inferential statistics (ANOVA and LSD) test.
Results: The biofresh mouth rinse which has high alcohol containing has less effect on
microhardness of tetric ceram than the zak &distiled water , while the effect
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The primary aim of this study was to find out the effect of a training program on the development of physical abilities in football goalkeepers. The current study was conducted on goalkeepers of the Academy of Espanyol Sports Club in the premises of Haifa Sports Club Stadium. The study was completed by the researchers within the timeline of May 2021 to August 2021. A total of 7 goalkeepers falling within the age group of 15-17 years were recruited as the sample participants for the study. Out of 7 goalkeepers, 5 goalkeepers were included in the primary experiment and 2 of them were excluded. The training program applied had a positive effect on the development of physical abilities in the football goalkeepers of the sa
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This study aims to observe the effect of melatonin implantation and exposure to different light colors and their interaction on productive in local Iraqi chicken. This study was conducted at the poultry farm of the Department of Animal Production/College of Agriculture/University of Baghdad/Abu Ghraib, on 252 birds (180 females and 72 males). The birds were divided into three sections (white, red and green) each section contains two lines, one of which has been planted melatonin under the skin of the neck of birds and the other has not been planted hormone. The results of the study showed significant improvement in productive traits such as egg proportion rate, egg weight, cumulative eggs number, egg mass and feed conversion rate. That the
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The accelerating effect of 1,4- phenylenediamine (PDA) additions in 1M hydrochloric acid solution at temperature rang (20-60) C° has been studied by weight losses measurement during ranging time (1-260) h and by following the pb2+ concentration in solution after several times by using Atomic absorption spectroscopy (AAS) . The volume of hydrogen gas involving was followed also in presence and absence of (PDA) in the corrosive solution .Accelerating enhanced by adding (NaCl , NaBr , NaI ) was also investigated.