Background: Removing dental plaque is important to maintain a good oral hygiene and prevent periodontal disease; this could not be accomplished by the use of toothbrush alone, it needs the help of interdental aids or intra-oral irrigator devices. The aim of this study was to compare the effect of using Waterpik flosser as adjunct to tooth brushing than using the dental floss with the brushing. Materials and methods: A single blind, six weeks study included 45 subjects divided into three groups of 15 subjects at each group. Group B (brushing) was instructed to use the toothbrush only, group BF (brushing & flossing) was instructed to use dental floss and tooth brushing while group BW (brushing and Waterpik flosser) was instructed to use Waterpik flosser in addition to the toothbrush. Plaque index, gingival index and bleeding on probing were measured at the 1st visit, after 3 weeks (2nd visit) and finally after 6 weeks (3rd visit). Results: The plaque index was significantly reduced in group BF and BW at the 3rd visit, while it showed no significant differences in group B. The mean percentage reduction of gingival index at the 3rd visit was higher in group BW than group B and group BF. Using the chi-square test, bleeding on probing showed no significant difference in group B, while there was significant reduction in group BF and highly significant reduction (p<0.001) in group BW between the visits. Conclusion: Waterpik flosser was more effective in reducing dental plaque and bleeding than dental floss.
In this work the strain energy of tetrahedrane and its nitrogen substituted molecules were calculated by isodesmic reaction method according to DFT quantum chemical fashion, the used basis set was 6-31G/B3-LYP, in addition all structures were optimized by RM1 semi-empirical method. From the obtained data we estimate an empirical equation connect between strain energy of the molecule with charge functions represented by dipole moment of the molecule plus accumulated charge density involved within the tetrahedron frame plus the number of nitrogen atoms. The results indicate the charge spreading factors by polarization and processes are the most important factors in decreasing the strain energy.
Developed and underdevelopment countries, on equal terms, face the problem of budget deficiency. Budget deficiency means that the public expenditure surpasses the public revenues. This, on the international level, is one of the most serious economic problems with many direct effects on the national economy, and depends, basically, on its finance chosen method. Looking for a solution to this problem, for this reason and many other ones, has been highlighted in spite of the many attempts to reduce the role of the governmental expenditure. Budget deficiency can not be attributed to a single unique cause since it is complex phenomenons the causes of which are related to many factors contribute to its occurrence, some of which refer t
... Show More
(1)
Many production companies suffers from big losses because of high production cost and low profits for several reasons, including raw materials high prices and no taxes impose on imported goods also consumer protection law deactivation and national product and customs law, so most of consumers buy imported goods because it is characterized by modern specifications and low prices.
The production company also suffers from uncertainty in the cost, volume of production, sales, and availability of raw materials and workers number because they vary according to the seasons of the year.
I had adopted in this research fuzzy linear program model with fuzzy figures
... Show More
(10)
(7)
In this paper, the maximum likelihood estimates for parameter ( ) of two parameter's Weibull are studied, as well as white estimators and (Bain & Antle) estimators, also Bayes estimator for scale parameter ( ), the simulation procedures are used to find the estimators and comparing between them using MSE. Also the application is done on the data for 20 patients suffering from a headache disease.