ABSTRACT
Background: Alloantibodies are antibodies that are produced in response to foreign antigens, the main stimuli responsible for erythrocyte alloantibodies in healthy adult donors are previous pregnancies and transfusions. Red blood cell [RBC] alloantibodies, especially IgG class, are clinically significant because of the association with hemolytic disease of newborns [HDN], hemolytic transfusion reaction [HTR] and a significant reduction in lifespan of transfused red blood cells. It has been stated that hemolytic reactions due to erythrocyte alloantibodies in donor blood is a relatively rare occurrence; however, they can occasionally cause severe transfusion reaction, particularly if given to infants and in the setting of massive transfusion
Objective: We aimed in this study to screen healthy Egyptian blood donors for the presence of red blood cells alloantibodies in a trial to prevent complications of blood transfusion, other secondary possible outcomes are to reveal the differential frequency of these alloantibodies among donors with previous blood transfusion, multiple pregnancies, different age groups and gender
Subjects and Methods: This study was carried out on 200 healthy Egyptian blood donors coming to Ain Shams University Hospitals Blood Banks. Data was collected on: gender, age, frequent donor or first time to donate, history of previous blood transfusion, number of pregnancies [in female donors], history of hepatitis or other viral infection, history of diabetes mellitus, hypertension, and history of recent surgery
Results: Sera from donors was subjected to alloantibody screening by manufacturers antibody screening cells [Grifols I+II+III], when positive screening test, alloantibodies identification was done by manufacturers antibody identification panel [Grifols], which consists of 11 panels. Out of the 200 donors, alloantibodies were detected in 8 donors [4%], a percent which is higher than other studies, may be due to the smaller sample size, alloantibodies were: anti-Kell in 1 case [12.5%], anti-M in 1 case [12.5%], and anti-C in 1 case [12.5%], anti-c in 1 case [12.5%], and anti P in 1 case [12.5%], and 3 [37.5%] cases were non-specific antibodies, 130[65%] of donors were males and 70 [35%] were females with a male to female ratio 1.8:1, their ages ranged from 19 years to 65 years with median of 32 years
Conclusion: Relation between alloantibodies and gender, multipara, repeated blood transfusion and previous surgeries was done showing statistically significance of previous surgeries and presence of allo-antibodies
ABSTRACT
This study was designed to study the effect of different surface treatments on ceramic/ cement bond strength
Material and Methods: Sixty six disc shaped Duceram LFC as well as 66 Inceram samples [3mm thickness and 6 mm diameter] were constructed and divided into 3 groups according to the type of surface treatment employed. Group 1 was Al[2]O[3] blasted, group 2 was HF etched and group 3 was copper coated. Each group of the tested ceramic was divided into 2 subgroups according to the type of cement used. Subgroup 1: twin samples were cemented with glass ionomer cement, subgroup 2: twin samples were cemented with resin cement. A stereomicroscope was used to measure the surface roughness of the differently treated ceramics and calculated the interfacial mean pore count and average pore size of cemented samples. A scanning electron microscope was used to study the surface topographic changes of the differently treated ceramics and calculated the interfacial mean pore count and average pore size of cemented samples. A scanning electron microscope was used to study the surface topographic changes of the differently treated ceramics. Shear bond strength values were measured using a universal testing machine. For the copper coated samples, optical measurement were taken using a spectrophotometer [N = 5 for each material] and color change delta E was calculated. All data were statistically analyzed using ONE WAY ANOVA
Results: The highest bond strength was obtained with the blasted and copper coated groups of the tested ceramics when glass ionomer cement was used. With resin cement, the HF etched Duceram and the blasted Inceram groups exhibited the highest shear bond values due to the increased surface roughness [Ra]. However the blasted Inceram recorded the highest shear bond values compared to the HF etched and copper coated groups with resin cement. Spectrophotometric measurements revealed no color changes [delta E] before and after copper coating
Conclusions: blasting and copper coating Duceram LFC and Inceram exhibited a high shear bond values with glass ionomer cement. Blasting or HF etching is recommended for Duceram LFC when resin cement is to be used. However, blasting of inceram is recommended when resin cement is to be used
ABSTRACT
Objective: To evaluate the fit of crowns constructed from metal ceramic nicke-chromium alloy, gold electroformed and Cerec 3 restoration systems
Materials and methods: A total of thirty crowns were fabricated in this study: two main groups: fifteen anterior and fifteen posterior crowns. Each group was divided into three subgroups, each of five crowns were designed as follows: five nickel-chromium ceramo-metallic crowns, five gold electroformed ceramo-metallic crowns and five Cerec 3 [all-ceramic] crowns. The vertical gap distance defined as the marginal opening between the prepared die margin and the most apical surface of the cast crowns was measured before and after porcelain application using a traveling microscope
Results: for the metal ceramic crowns before porcelain application both systems showed clinically accepted range of marginal gap but the gold-electroformed system showed better marginal fit. After porcelain application the metal ceramic systems showed distortion in marginal fit than before porcelain application. The gold-electroformed anteriors system was significantly distorted more than the nickel-chromium and Cerec 3 systems. The posterior crowns were insignificantly different from each other and within the clinical acceptable range for marginal gap
Conclusion: 1- The posterior crowns are within the clinical acceptable range for marginal fit for all systems before and after porcelain application. 2- The nickel-chromium and the gold-electroformed systems are within the clinical acceptable range for marginal fit before porcelain application. 3- The high temperature used during the firing of porcelain affect the marginal fit of a metal-ceramic restorations. 4- The distortion in the marginal fit of anterior crowns was pronounced for the gold-electroformed system after porcelain application. 5-CAD/CAM [Cerec 3] crowns represent good technology compare to other fabricated techniques
ABSTRACT
Dentists should realize that restorative materials intended to be used in patients receiving radiotherapy in the head and neck regions, must be capable of withstanding standard radiation dose [6070Gy = 6000-7000 rad] without serious changes in their functional stability. Two types of each of the currently used restorative amalgam and resinous composite, namely amalgam world and amalgam cap, as well as composite arabesk and composite pekalite, were employed throughout the present work. A factorial experiment was designed to evaluate their radiation sensitivity. Using 6 Mev photon beam, standardizely prepared samples were exposed to two doses of 60 and 70 Gy representing the usual dose range that are delivered as postoperative or radical radiation dose respectively. In comparison with the controls, radiation sensitivity of the different restorations was estimated via changes in properties known to be closely relevant to their successful functionality. The properties followed were electrochemical corrosion, chemical solubility, hardness microstructure and surface roughness. Though the statistically treated results obtained offered only a partial set of judgment criteria, it was concluded that amalgam cap and composite arabesk appeared to possess the most functional durability with respect to the corresponding class of each. Moreover irradiated amalgam cap acquired more noble character in resisting corrosion attack, while irradiated composite arabesk gained a significant increase in its mechanical hardness and disintegration resistance as a result of undergoing cross-linking reaction