Background: one of the complications of power bleaching is surface roughness of enamel which increases the possibility of post bleaching teeth discoloration. The aim of the present study is to evaluate the effect of toothpaste containing nano hydroxyapatite, NovaMin and kin sense fluoride on surface roughness of human tooth enamel after laser bleaching with 35% hydrogen peroxide bleaching gel. Materials and Methods: Twenty human enamel incisors were cleaned and their labial surface polished up to #1200, then categorized into four equal groups; first group kept without bleaching as a control group, while the remaining three experimental groups were bleached with 35% hydrogen peroxide, and each group treated with a restore paste containing one of the following: nano hydroxyapatite, NovaMin, and Kin fluoride. Bleaching was done with laser hybrid system (DMC Whitening Lase II, Sao Paulo, Brazil). Enamel roughness values assessed by an atomic force microscopy (AA3000, Bosten, USA) before and after treatment with restore tooth paste. Results: Paired t-test used to compare the mean roughness values before and after treatment with each restore paste. One-way analysis of variance and Duncan post hoc tests used to determine the differences between mean roughness values of the groups. A p-value of 0.05 or less considered a significant. The results showed a highly significant statistical differences of remineralization of all types of restore tooth pastes. Conclusions: Nano hydroxyapatite past exhibiting a higher ability to reduce the surface roughness after laser bleaching than other tested pastes.
Abstract
The research aims to identify tax exemptions, their objectives and types, as well as to shed light on the concept of sustainable development, its objectives, dimensions and indicators (economic, social and environmental), as well as to analyze the relationship between tax exemptions and economic development, in addition to measuring and analyzing the impact of tax exemptions on economic development in Iraq for the period ( 2015 - 2021) using the NARDL model. The research problem centers on the fact that failure to employ financial policy tools correctly led to a weakness in achieving economic justice, which leads to a failure to improve social welfar
... Show Moredifferent ?? ? injury ? This study aims to knowing the affect of embargo on cancer tutors in Iraq according to different body systems , In addition, this '?0 kinds study aims at knowing t^e categories ages that can be mostly injured by the cancer Egression analysis and descriptive statistics( median and frequency tables). ^?^???? have been used to achieve these two aims .This study includes ah the seventy cancer s Iraq from 1980-1998 and the data have been from the Ministry of Health / ?? tumors Iraqicancer board administration / central registry. The results of this study are emale productive? : Embargo has affected the ten different body systems as .? central nervous system and opthamamology , Hematology ,Respiratory ? system system , mal
... Show MoreThe research aims to detect the problems of educational reality faced by university professors and identify statistically significant differences in the academic problems of university instructors. It has adopted an analytical descriptive research approach to achieve research objectives and identifies the study community with professors of public and private universities. A random sample of 250 instructors was selected for the purpose of applying the questionnaire to them, knowing the academic problems encountered in the course of their work at universities, and adopting appropriate statistical means to process and analyze the data. The research concluded with a set of results, including that all fields (infrastructure, admission of
... Show MoreA lotic ecosystem is considered a source of carbon dioxide (CO2) in the atmosphere where it becomes supersaturated with CO2, which contributes to the global carbon cycle. To enhance our comprehension of the roles of CO2 in rivers, an outdoor experiment was designed with controlled carbon source inputs to investigate the roles of the dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in the phytoplankton community. Plastic enclosures were installed in the Tigris River within Baghdad for that goal. Samples were collected on the first day, as well as on the 5th and the 12th days from 14 enclosures. The enclosures were treated by artificial glucose (C6H12O6) (10, 20, 30mg/ l) as DOC sources, while sodium bicarbonate (NaHCO3) (1
... Show MoreIn this study, the relationship between the bare soil temperature with respect to its salinity is presented, the bare soil feature is considered only by eliminating all other land features by classifying the site location by using the support vector machine algorithm, in the same time the salinity index that calculated from the spectral response from the satellite bands is calibrated using empirical salinity value calculated from field soil samples. A 2D probability density function is used to analyze the relationship between the temperature rising from the minimum temperature (from the sunrise time) due to the solar radiation duration tell the time of the satellite capturing the scene image and the calibrated salinity index is presented. T
... Show MoreAn experimental study is made here to investigate the discharge coefficient for contracted rectangular Sharp crested weirs. Three Models are used, each with different weir width to flume width ratios (0.333, 0.5, and 0.666). The experimental work is conducted in a standard flume with high-precision head and flow measuring devices. Results are used to find a dimensionless equation for the discharge coefficient variation with geometrical, flow, and fluid properties. These are the ratio of the total head to the weir height, the ratio of the contracted weir width to the flume width, the ratio of the total head to the contracted width, and Reynolds and Weber numbers. Results show that the relationship between the discharge co
... Show Moreto study the discribrion and the pollution in the environment in the south of baghdad samples of waste water from industrail units using the mercury in its process also