Background: Plaque retention during fixed orthodontic therapy is an important cause of developing enamel demineralization. The purpose of this study was to evaluate the effect of different brackets types on the count of Streptococcus Mutans in orthodontic patients using conventional fluoridated toothpaste. Materials and Methods: Plaque samples were collected from maxillary 1st premolar teeth of twenty right handed patients (using split mouth technique) before bonding, after 48 hrs of bonding using tooth brush only, and after 2 weeks of using fluoridated toothpaste. Stainless steel bracket was bonded on right first premolar while the left one was bonded with sapphire bracket. The calculation of the Streptococcus Mutans count was done using the plate counting method utilizing colony counter. The differences between the two types of brackets were determined using the Wilcoxon signed ranks test. Results: The median bacterial count on the right side was insignificantly higher than the left side; streptococcus mutans in the plaque sample around the sapphire brackets showed insignificantly less counts than around the stainless steel one, when the patients used tooth brush only or fluoridated toothpastes. Fluoridated toothpastes reduced streptococcus mutans insignificantly around both types of brackets. Conclusion: Fluoridated toothpaste acts effectively in reducing streptococcus mutans colony counts around sapphire and stainless steel brackets. Keywords: Streptococcus mutans, Stainless steel brackets, Sapphire brackets.
The effect of nitrogen fertilizer and the planting distance on growth and yield of the sunflower cultivar (Taka) was investigated. The experiment was conducted in the field using five nitrogen fertilizer levels (0, 50, 100, 150, 200) kg/donum and three planting distances (10, 20, 30) cm/plant. The experiment design was split-plot by using RCBD with four replicates. The level of fertilizer as the main plot, while the planting distance as the sub plot. Plant high and yield components were measured. Results indicated that using 200 kg/donum of nitrogen and 30 cm/plant of planting distance gave the highest rate of 1000 seeds weight and the number of seeds/ head. While using 200 kg/donum of nitrogen fertilizer with 10 cm/plant of planting dista
... Show MoreThe purpose of this study is designate quenching and tempering heat treatment by using Taguchi technique to determine optimal factors of heat treatment (austenitizing temperature, percentage of nanoparticles, type of base media, nanoparticles type and soaking time) for increasing hardness, wear rate and impact energy properties of 420 martensitic stainless steel. An (L18) orthogonal array was chosen for the design of experiment. The optimum process parameters were determined by using signal-to-noise ratio (larger is better) criterion for hardness and impact energy while (Smaller is better) criterion was for the wear rate. The importance levels of process parameters that effect on hardness, wear rate and impact energy propertie
... Show MoreThe effect of the concentration of the colloidal nanomaterial on their optical limiting behavior is reported in this paper. The colloids of sliver nanoparticles in deionized water were chemically prepared for the two concentrations (31 ppm and 11ppm). Two cw lasers (473 nm Blue DPSS laser and 532 nm Nd:YAG laser) are used to compare the optical limiting performance for the samples. UV–visible spectrophotometer, transmission electron microscope (TEM) and Fourier Transformation Infrared Spectrometer (FTIR) were used to obtain the characteristics of the sample. The nonlinear refractive index was calculated to be in the order of 10-9 cm2/W. The results demonstrate that the observed limiting response is significant for 532nm. In addition, t
... Show MoreCeramic to metal joining technique, which was used in this investigation includes the use of active filler alloy as a sandwich between the alumina and kovar alloy for brazing. High purity powdered metals of silver, copper, and additives of titanium were used to prepare the active filler alloy, through compacting the mixed powders and alloying in a furnace with argon atmosphere at the temperature of 800oC for 10 minutes. To use it as an active filler metal, it has been modified to a proper thickness. Two groups of alumina were prepared with different sintering temperatures (1450oC and 1650oC) and each group was tested under atmospheric pressure, vacuum furnace pressure of 2*10-4 torr and vacuum furnace pressure of 2*10-6 torr. All the pro
... Show MoreThe experiment was conducted using Potato( Solanum tuberosum L.) at the eastern Radwaniyah at private field during fall season 2020/2021 and spring 2021 to study the effect of nitrogen levels to 350, 275, 200 kg N h-1 ( N1, N2, N3) and phosphorous to 100, 180, 360 kg P2O5 h-1 ( P1, P2, P3) and potassium to 100, 200, 300 kg K2O h-1 ( K1, K2, K3) to vegetative growth and yield of industrial potato, The seeds of the hybrid potato Sinora, Class A, were planted in the fall season on 15/9/2020 and Elite in the spring season on 31/1/2021. The experimental fertilizers were added in four batches and in proportions according to the stages of plant age, Factorial experiment with RCBD using three replications. The results showed that changing t
... Show MoreAn experiments were carried out at the College of Veterinary Medicine, University of Baghdad, during the period from October 26th 2023 to December 20th 2023, to study the effect of pasteurizing treatments of shell table egg using traditional Microwave oven on its quality characteristics during Zero, 1, 2, 4 and 8 weeks of refrigerator storage. A total of 120 fresh table eggs (White shell eggs) were collected from 20000 Luhman layer hens flock at Al-Amir project commercial farm, Al-Musaib city. These eggs were divided into 4 treatment of microwave pasteurization treatments which were Zero, 10, 20, and 30 sec. Results revealed that significant differences (P<0.05) for the internal characteristics of the egg after storage for 2, 4
... Show MoreExperiments were carried out at the College of Veterinary Medicine, University of Baghdad, during the period from October 26th 2023 to December 20th 2023, to study the effect of pasteurizing treatments of shell table egg using traditional Microwave oven on its quality characteristics during Zero, 1, 2, 4 and 8 weeks of refrigerator storage. A total of 120 fresh table eggs (White shell eggs) were collected from 20000 Luhman layer hens flock at Al-Amir project commercial farm, Al-Musaib city. These eggs were divided into 4 treatment of microwave pasteurization treatments which were Zero, 10, 20, and 30 sec. Results revealed that the numbers of total bacteria and total coliform on the surface of table egg shells is affected by pasteuri
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