The purpose of this work was to study the effects of the Nd:YAG laser on exposed dentinal
tubules of human extracted teeth using a scanning electron microscope (SEM). Eighty 2.5mm-thick
slices were cut at the cementoenamel junction from 20 extracted human teeth with an electric saw. A
diamond bur was used to remove the cementum layer to expose the dentinal tubules. Each slice was
sectioned into four equal quadrants and the specimens were randomly divided into four groups (A to D ).
Groups B to D were lased for 2 mins using an Nd:YAG laser at 6 pulses per second at energy outputs of
80 , 100 and 120 mJ. Group A served as control. Under SEM observation, nonlased specimens showed
numerous exposed dentinal tubules. SEM observation revealed that application of Nd:YAG laser at
energy output of 80 mJ may cause melting of dentin and partial closure of exposed dentinal tubules
without dentin surface cracking. But when the energy output raised to 100 and 120 mJ more sealing of
dentinal tubules occurs. Heat generation occurred in all lased groups but the amount of temperature
increase was within the permissible limits(less than 5.5⁰C). The measured sealing depths were from 3-
5μm for groups B-D and the width of the created groove was 30μm in all lased groups. In conclusion
lasing with nanosecond Nd:YAG with a wavelength of 1064nm at 120mJ with 6Hz for 2 minutes (group
D) shows the efficient laser parameters for complete sealing of exposed dentinal tubules without
temperature increase to the damaging level of the pulp tissue.
This research aims to identify the relationship between occupational hypocrisy and organizational strategic success, It was done by analyzing the correlations and influence between variables, applied to a random sample of university professors at the University of Kufa faculty of administration and economic.
The main tool for data collection is the survey were questionnaires were distributed randomly to the professors , and (43) questionnaires were returned, and test its validity by using (SEM) (Structural Equation Modeling), Hypothesis has been tested by using Statistical Package for Social Sciences (SPSS v. 18), The research found a set of conclusions:(The occupational hypocrisy has
... Show MorePraise be to God, Lord of the Worlds, and prayers and peace be upon the Master of Messengers and his family and companions.
The study of the jurisprudential opinions of scholars, their choices, or their weightings, sheds light on the approach they followed in their choices, and reveals the originality of the scholar or his influence on those who preceded him from among the scholars.
And the commentators of the noble hadith of the Prophet have their important contributions in this aspect, as they undertake the task of explaining the noble hadith, the second source of legislation
Contemporary commentators have their share in the service of the honorable hadith, and the statement of their choices and preferences, and am
... Show MoreThis study aimed to know the impact of the capital structure measured by the ratio of financing to short-term capital and the ratio of financing to long-term capital on the profitability of companies, as measured by the rate of return on assets and the rate of return on equity. The study was applied to industrial sector companies listed in the Iraq Stock Exchange. The financial number of (14) companies, and (4) companies were selected that met the conditions for selecting the study sample. The study methodology relies on the analytical method as it is more appropriate to the nature, scope and objectives of the study, and the ready-made statistical program "SPSS" will be used to analyze the relationships and influence between the
... Show MoreA Photo Dynamic Therapy (PDT) is a technique which is used with Laser to treat many of cancer
tissues. This paper deals with the relatively new therapeutic technique (PDT) with pulsed Nd:glass Laser
which was applied to human soft tissues (Ovary and Kidney tissues), and to the hard tissues (freshly
extracted human teeth), with power density of 280 watt/mm2 and exposure time 330 usec. Different
dyes (Blue, methylene, eosin, and orange) were applied to the area before irradiation to study the effect
of the pigments on the laser interaction with biological tissues. The zone of treatment (Z-necrosis) with
aid of MATLAB was determined. The relationship of zone of treatment with exposure time,
accumulated damage and fracti
Objective. Infection with Coxsackie virus. This virus that damages pancreatic cells, has long been linked to the onset of insulin-dependent diabetic mellitus (IDDM). Pro-inflammatory cytokines can be produced as a result of this illness. Tumor necrosis factor-a is one of these pro-inflammatory cytokines. Materials and Methods. Blood sample were collected from 180 Iraqi participants. Ninety of them is type 1 diabetic patients and other 90 is healthy control .both groups were tested for the incidence of Coxsackie virus B IgG. So the patients groups is divided to two groups according to sero positivity of CVB-IgG .all 180 patients tested to measure of level of TNF-α. Results. The Results showed increasing in levels of TNF-α in CBV po
... Show Moreabstract
The grammatical tools (the letters of meanings) are of great importance in understanding the meanings of the Arabic sentences,
This research is a simple attempt to show how our venerable scholars employed the meanings of these tools when they interpreted the linguistic evidence, that is, the grammatical structure largely depends on the tool in forming the meaning within the sentences and employing the meanings of these grammatical tools in explaining the linguistic evidence by clarifying their significance in the contexts of their use and effectiveness. Synthesis of the meanings of grammatical tools is an important tool in understanding the linguistic structure in order to reveal its meaning.
... Show MoreThe summary:
This research paper presents a standard economic study. This study aims to build an economic standard form of the investment effect in Human Capital on Economic Growth in Algeria. The study showed that there is an inverse relationship between the investment and human capital. This is expressed by expending on education and economic growth. This contradicts with the economic theory. Such matter could be explained by that expending on education does not contribute in the economic growth. This refers to that the education sector result does not employee or save jobs. Thus, it does not contribute in growth; in addition, the Algerian economy depends on petrol in the first class. This means the ab
... Show MoreObjectives: To study the prevalence of rs1799964 (-1031 T/C) and rs361525 (- 238 G/A) SNPs and their effect on the disease activity, severity, and cytokines production in newly diagnosed Iraqi rheumatoid arthritis patients. Patients and Methods: sixty-three patients were diagnosed by a specialist physician while attending the rheumatology unit and twenty control participated. The inflammatory markers were measured and PCR amplification and sequencing were performed to demonstrate TNF-α SNPs. Results: Regarding (-1031 C/T) SNP, the TT genotype and allele C were significantly present in the controls, and the CT genotype was distributed significantly in the patients. The TT genotype was mostly distributed in the mild-moder
... Show MoreBackground: The bonded orthodontic retainer constructed from multistrand wire and composite is an efficient esthetic retainer, which can be maintained long-term. Clinical failures of bonded orthodontic retainers, most commonly at the wire/composite interface, have been reported. This in vitro investigation aimed to evaluate the tensile forces of selected multistrand wires and composite materials that are available for use in the construction of bonded fixed retainers. Materials and Methods: The study sample includes 120 wires with three types of retainer wires (3 braided strands\ Orthotechnology, 8 braided strands\ G&H Orthodontics, 6 coaxial strands\ Orthoclassic wires), two types of adhesive (flowable\ Orthotechnology, non flowable\ G&H O
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