Background: This in vitro study evaluated the fracture resistance of weakened endodontically treated premolars with class II MOD cavities restored with different composite restorations (Low-shrinkage Filtek P90, nanohybrid Filtek Z250 XT and SDR bulk fill). The type and mode of fracture were also assessed for all the experimental groups. Materials and Method: Fifty human adult maxillary premolar teeth were selected for this study. Standardized extensive class II MOD cavities with endodontic treatment were prepared for all teeth, except those that were saved as intact control. The teeth were divided into five groups of ten teeth each (n=10): (Group 1) intact control group, (Group 2) unrestored teeth with endodontic treatment, (Group 3) restored with (Filtek Z250 XT), (Group 4) restored with SDR bulk-fill flowable composite and (Group 5) restored with Filtek P90 composite. All specimens were subjected to compressive axial loading until fracture in a universal testing machine. The data were statistically analyzed using one-way ANOVA test and LSD test. Macroscopic fracture type were observed and classified into favorable and unfavorable. Specimens in group 3, 4 and 5 were examined by stereomicroscope at a magnification of 20× to evaluate the mode of failure into adhesive, cohesive or mixed. Results: The mean fracture load was (1.123 Kn) for group 1, (0.545 Kn) for group 2, (0.687 Kn) for group 3, (0.799 Kn) for group 4 and (0.672 Kn) for group 5. Using one way ANOVA test a highly significant difference (P < 0.01) were found among all groups. The use of bulk-fill flowable composite improved the fracture resistance significantly in comparison to silorane and non-significantly to Filtek Z250 XT. Filtek Z250 XT showed better improvement in fracture resistance but with no significant differences in comparison to Filtek P90 composite restorations. The type of failure was unfavorable for all the restored groups. Conclusion:All experimental composite restorations showed significant improvement in the resistance to cuspal fracture in comparison to unrestored one. However, under the conditions of this study, direct composite restorations should be considered as a valid interim restoration for weakened endodontically treated teeth before cuspal coverage can be provided.
SKF Dr. Abbas S. Alwan, Dhurgham I. Khudher, INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY, 2015
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The present study is concern with the interaction between the naidid worms diversity and the species of aquatic plant within which the worms found . For this purpose, two species of aquatic plant were used, Ceratophyllum demersum and Eichhornia crassipes. 12 samples of aquatic plants were collected , as one sample monthly for a period from September 2012 to September 2013 from different site on Tigris river within Baghdad City. From C. demersum, 1428 individuals, were sorted during the study period, related to 17 species. 12 species of subfamily Naidinae which are Chaetogaster limnaei , C. diastrophus , Ophidonais serpentine , Dero ( Dero) digitata. , D.(D.) evelinae , Nais pseudobtosa , N.simplex, N.stolci , N.Paradalis , N.elingiu
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Objectives: To study the spectrum and classification of ATP7B variants in Iraqi children with Wilson disease by direct gene sequencing with clinical correlation. Methods: Fifty-five unrelated children with a clinical diagnosis of Wilson disease (WD) were recruited. Deoxyribonucleic acid was extracted from peripheral blood samples, and variants in the ATP7B gene were identified using next-generation sequencing. Results: Seventy-six deleterious variants were detected in 97 out of 110 alleles of the ATP7B gene. Thirty (54.5%) patients had 2 disease-causing variants (15 homozygous and 15 compound heterozygous). Twelve (21.8%) patients had one disease-causing variant and one variant of uncertain significance (VUS) with potential pathogenicity. T
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Background: Anterior disc displacement with reduction (ADDWR) is the most common form of the internal derangement (ID) of temporomandibular joint (TMJ). It is a painful progressive dysfunction and clinically characterized by reciprocal clicking due to shift in the disc anteriorly in relation to the condyle and fossa during mandible elevation. Minimally invasive therapy such as intra-articular injection of platelet-rich plasma (PRP) has been used. PRP is a natural autologous product with a high platelet concentration obtained by centrifugation process to enhance tissue healing through several growth factors (GFs), which are released after endogenous activation. The aim of this study is to assess this technique which is increasingly used toda
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Liquefied petroleum gas (LPG), Natural gas (NG) and hydrogen were all used to operate spark ignition internal combustion engine Ricardo E6. A comparison of CO emissions emitted from each case, with emissions emitted from engine fueled with gasoline as a fuel is conducted.
The study was accomplished when engine operated at HUCR for gasoline n(8:1), was compared with its operation at HUCR for each fuel. Compression ratio, equivalence ratio and spark timing were studied at constant speed 1500 rpm.
CO concentrations were little at lean ratios; it appeared to be effected a little with equivalence ratio in this side, at rich side its values became higher, and it appeared to be effected by equivalence ratio highly, the results s
... Show MoreBackground: The purpose of this study was to evaluate and compare centering ability and canal transportation of simulated S-shaped canals instrumented with four different types of rotary nickel-titanium systems. Materials and Methods: Forty simulated S-shaped canals in resin blocks were divided into four groups of ten each and were instrumented to an apical size 25 by different instrumentation technique using ProTaper Universal files (group A), ProTaperNext (group B), Reciproc (group C) and WaveOne (group D).Centering ability and canal transportation was measured at (11) measuring points from D0 to D10 bysuperimposion of the pre- and post-operative images obtained by using digital camera in standardized manner. An assessment of the canals
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