Background: The oral cavity is considered as a complex ecological niche, its complex microbial community is reflected to it. Streptococcus mutans has been implicated as one of the major etiological factor of dental caries. Tooth surfaces colonized with Streptococcus mutans are at a higher risk for developing caries, while lactobacilli are considered as the secondary invaders, not initiators of the carious lesion. The main purpose of this study was to correlate the dental caries (for primary and permanent teeth) in the upper jaw with the streptococcus mutans and lactobacilli count in the dental plaque and saliva, also to correlate the dental caries (for primary and permanent teeth) in the lower jaw with the streptococcus mutans and lactobacilli count in the saliva. Materials and methods: Forty seven children aged 5-9 years old were selected for this study. Dental caries recording was carried out by the dmfs index (decayed, missed, filled surfaces for primary teeth) to inspect the primary teeth and DMFS index (decayed, missed, filled surfaces for permanent teeth) to inspect the permanent teeth, by using the dental mirror and explorer. Collection of salivary samples was performed in the morning between (10-11) a.m. at least one hour after breakfast, then normal saline was added to have tenfold dilutions, for the purpose of full colony counting of the caries related microorganisms (streptococcus mutans and lactobacilli), then inoculation was done in the special selective media (for the streptococcus mutans is Mitis-Salivarius-Bacitracin agar, and for the lactobacilli is Rogosa agar). Counting of the colonies of the bacteria were estimated by the aid of dissection microscope Results: The highest level of dmfs means was found in primary upper teeth, it was 17.6383 ± 10.10 while for the permanent teeth the mean of DS and DMFS was highest in the lower teeth, it was 0.7391 ± 1. Pearson correlation was used to show the correlation between the ds and dmfs of upper and lower primary teeth with the level of streptococcus mutans in saliva (sm. Sal) and lactobacillus in saliva ,there was a significant correlation between the ds and dmfs for upper primary teeth at level 0.01 (2-tailed), and there was negative correlation between dsl and level of streptococcus mutans in saliva (sm. Sal) also there was negative correlation between dmfs for upper and lower primary teeth with level of streptococcus mutans in saliva, also the correlation between lactobacillus level in plaque with streptococcus level in plaque was negative, while for upper permanent teeth the correlation was negative with both type of bacteria level in plaque with the DSU and DMFSU Conclusion: The caries activity was more prominent in upper teeth than lower teeth, levels of streptococcus mutans were not associated with high caries activity, which emphasizes and consistent with the fact that the dental caries is a multifactorial disease, related to many factors.
Industrial development has recently increased, including that of plastic industries. Since plastic has a very long analytical life, it will cause environmental pollution, so studies have resorted to reusing recycled waste plastic (sustainable plastic) to produce environmentally friendly concrete (green concrete). In this research, producing environmentally friendly load-bearing concrete masonry units (blocks) was considered where five concrete mixtures were compressed at the blocks producing machine. The cement content reduced from 400 kg/m3 (B-400) to 300 kg/m3 (B-300) then to 200 kg/m3 (B-200). While (B-380) was produced using 380 kg/m3 cement and 20 kg/m3 nano-sil
... Show MoreIn recent years, various methods have been developed to enhance the characteristics of asphalt pavement in order to face the continuous challenges of increasing traffic loads and changing climate conditions. One of the most popular and successful methods is modifying the asphalt mixtures or asphalt binder with the addition of polymers. Therefore, two types of Polyethylene (PE) polymer, High-Density PE (HDPE) and Low-Density PE (LDPE), are used in this research. Two methods were applied to prepare PE-modified asphalt mixtures: Semi-Wet Method (S-WM) and Dry Method (DM). The findings of the investigation indicated that the addition of PE polymer can reduce the wear loss of aggregate. In general, the experimental results revealed that asphalt
... Show MoreA novel technique for nanoparticles with a chemical method and impact for resistance bacteria methicillin-resistant Staphylococcus aureus (MRSA), UV-visible analysis confirmed the by Fourier transform infrared spectroscopy (FT-IR) and Energy dispersive X-Ray (EDX), Scanning electron microscope (SEM) and X-ray diffraction pattern estimation antimicrobial excellent antibacterial activity against MRSA (with zone of inhibition of 11 ± 02 mm , 9 ± 01 mm,8 ± 03 mm and 7.5 ± 02 mm and 6.5 ± 02 mm) at different concentrations (0.5 ,0.25, 0.125, 0.0625, 0.03125) mg/ml while good activity was 16 ± 03 mm at 17 ± 02 mm zone at 0.25, 0.125 mg/mL, respectively. The increase in microorganism resistance to antibiotics a couple of have caused
... Show MoreThe enhancement of the thermal and thermo-hydraulic performance of a semi-circular solar air collector (SCSAC) is numerically investigated using porous semi-circular obstacles made of metal foam with and without longitudinal porous Y-shaped fins. Two 10 and 40 PPI porous material samples are examined. Three-dimensional models are built to simulate the performance of SCSAC: model (I) with clear air passage; model (II) with only metal foam obstacles, and model (III) with metal foam obstacles as well as porous Y-fins. COMSOL Multiphysics software version 6.2 based on finite element methodology is employed. A conjugate heat transfer with a (k-ε) turbulence model is selected to simulate both heat transfer and fluid flow across the entir
... Show MoreAbstract This study aims to compare British war poetry of the First World War with Iraqi poetry from the mid-20th century with special reference to Iraqi war poetry of the 1980’s Iraq-Iran War and the period that followed it. It will also investigate the influence of the designated British war poetry on the chosen body of Iraqi poetry. Through the comparison of sample poems the study presents, firstly, the direct influence of the British poetry of the Great War and its translation which formed the seeds of a more radical movement in Iraqi poetry during the 1980’s Iran/Iraq War and the period that followed it. The study also presents a comparison of the works of British and Iraqi civilian poets during and after the war time and their con
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