Background: The aim of this study was to determine phototoxic effect of visible blue light on anaerobic periodontal pathogens namely Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Materials and methods: Strains of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were isolated from pockets of systemically healthy patients aged between 35-55 years old with pocket depths of 5-6 mm, the bacteria cultured on special blood Agar plates solid media, then subjected to visible blue light emitted from commercially available light cure devise (LED curing light); that emits blue light (400-500nm) of 1000mw energy at different periods of time exposures, then the CFU of each plate was measured by direct colony count with the aid of open CFU software after 48hours of anaerobic incubation. Results: There was a decrease in CFU for both microorganisms as we proceeded from zero, 20, 40 and 60 seconds of blue light exposure. Conclusion: there was a phototoxic effect for the visible blue light emitted from the light curing device against the anaerobic periodontal pathogens. Key words: Blue light, CFU, anaerobic periodontal pathogen.
A low-cost, RGB LED-based visible-light spectrophotometer was designed to measure dyes concentration. Dyes are widely used as indicators or coloring agents in different applications and knowing their concentration is an essential part for many studies. The proposed spectrophotometer provides many functionalities that clones the traditional expensive spectrophotometers for a budged price under $50. It was aimed to provide a versatile tool for instructors and educators to teach their students the fundamental concepts behind spectrophotometry. Malachite green, methyl red, and methyl orange dyes were chosen to be good samples to show the integrity of the proposed spectrophotometer in terms of accuracy, repeatability, and sensitivity as
... Show MoreABSTRACT Background:Hydrogen absorption and related degradation in the mechanical properties of Ni-Ti based orthodontic wires has been demonstrated following exposure to fluoride prophylactic agents. This study was designed to investigate the effects of three fluoride containing agents on the load deflection characteristics of heat activated nickel titanium arch wires during unloading phase. Material and method: Eighty specimens of heat activated nickel titanium arch wires were obtained from Ortho Technology Company, half of which had a 0.016 inch round and 0.019x0.025 rectangular. Ten specimens from both wire size were immersed in one of the tested fluoride prophylactic agents (neutral sodium fluoride gel, stannous fluoride gel or phos-flu
... Show MoreABSTRACT Background: One of the challenges to use chlorhexidine is its effect on the amount of microleakage after restoration; however, use of the materials with antibacterial properties after tooth preparation and before restoration has been widespread. The objective of this, in-vitro, study was to evaluate the influence of consepsis (chlorhexidine gloconate disinfectant) application on microleakage in class II cavities restored with light cured composite using universal adhesive system; etch and rinse technique –self etch technique. Materials and Methods: Forty class II cavities were prepared on mesial and distal surfaces of 20 non-carious mandibular third molars. The cavities were divided into four groups; (n =10 for each group).
... Show MoreBackground: Coated aesthetic archwires are currently the existing solutions for the esthetic problem, but the color of these archwires tends to change overtime. This study was aimed to evaluate the color stability of different types of esthetic archwires from four different companies at different time periods after immersion of two different staining drinks which are tea and Pepsi cola. Materials and methods: 48 specimens were prepared, each specimen contains 10 aesthetic archwires; and were divided according to type of solution into two groups: A (tea) &B (Pepsi cola); each group contained 24 specimens (12 specimens were immersed in the staining solution as 4 specimens for each time intervals and 12 specimens were immersed in distilled wa
... Show MoreBackground: The aim of this study was to measure the radiopacity (RO) of modified microhybrid composite resins by adding 2 types of nanofillers (Zinc Oxide and Calcium Carbonate) in two concentrations 3% and 5% and comparing them to unmodified microhybrid composite resins and to nanofilled composite resin. Materials and Methods: Two types of composite resin were used (Microhybrid composite MH Quadrent anterior shine and Nanofilled composite resin Filtek Z350 XT), for each tested group five disk-shaped specimens (1-mm-thick and 15 mm diameter) were fabricated. The material samples were radiographed together with the aluminum step wedge. The density of the specimens was determined with a transmission densitometer and was expressed in term of
... Show MoreResin-modified glass ionomer cement tends to shrink due to polymerization of the resin component. Additionally, they are more prone to syneresis and imbibition during the setting process. This
Today the NOMA has exponential growth in the use of Optical Visible Light Communication (OVLC) due to good features such as high spectral efficiency, low BER, and flexibility. Moreover, it creates a huge demand for electronic devices with high-speed processing and data rates, which leads to more FPGA power consumption. Therefore; it is a big challenge for scientists and researchers today to recover this problem by reducing the FPGA power and size of the devices. The subject matter of this article is producing an algorithm model to reduce the power consumption of (Field Programmable Gate Array) FPGA used in the design of the Non-Orthogonal Multiple Access (NOMA) techniques applied in (OVLC) systems combined with a blue laser. However, The po
... Show More60 patients diagnosed as having urticaria were included in the study ; 30 patients were effected with acute urticaria and 30 patients were affected with chronic urticaria. In addition, 30 healthy adult volunteers were selected as control group .The patients and control groups sera were examined with enzyme linked immunosorbent assay ( ELISA) to detect total level IgE and radial immunodiffusion (RID) to detect levels of IgG , IgA and IgM . The total level of IgE in acute urticaria ( 1.45±0.13) IU/mL and chronic urticaria (2.12 ± 0.10) IU/mL patients were significantly higher than the control groups ( 0.85 ± 0.10)IU/mL (p<0.05). The level of IgG in acute urticaria ( 12.5± 0.42) g/L and chronic (13.16±0.40) g/L patients , IgA in acute (2.
... Show MoreThe study aimed to establish the association of miR-153-3p expression with treatment response to IM in CML patients. Sixty CML patients were included and divided into two groups consistent with their response to treatment whether sensitive or resistant to IM. Ten healthy normal participants were enrolled as control group. RNA was extracted from serum to work out miR-153-3p expression utilizing real-time quantitative reverse transcription polymerase chain reaction. The primers were supplied by Macrogen Inc. Twenty seven patients were sensitive to imatinib and 33 were resistant to imatinib. The ratio of male to female was 1.14:1. The bulk (58%) of patients were within the age range of 41-60 years. Weight and gender did not significantly diffe
... Show Moreto evaluate the effect of various Nd:YAG frequency doubled laser parameters on the acid
dissolution and the progression of in vitro caries like lesions in human enamel.
Materials and Methods: Human extracted caries free upper first premolar teeth were collected for
this study. The irradiated teeth were divided into two groups. The first group was irradiated with
continuous Nd:YAG laser radiation, and the second group was irradiated with chopped Nd:YAG laser
radiation. For the first group, power and exposure time were changed while for the second group
power and number of pulses were changed. The spot diameter was kept constant for all the samples.
Results: using 1.5 W and 3 seconds (exposure time), best results among