The purpose of this study is to investigate the histopathological response of dentinopulpal
response of human teeth to the Er: YAG laser cavity preparation in comparison with the conventional
class I cavity preparation. Thirty five sound human upper and lower first premolar teeth which were
needed to be extracted for orthodontic purposes were used in the study. Regarding to the method of
cavity preparation, the teeth were grouped into three groups; Group1; Control group which consists of
seven sound teeth without cavity preparation, Group2; Conventional cavity preparation group and group
3; Er: YAG laser cavity preparation group. Each of Group2 and3 consists of fourteen teeth that is
subdivided into: A. 7teeth that extracted after two days after cavity preparation and B. 7 teeth that
extracted after twenty-one days after cavity preparation. Er: YAG Laser device emits radiation at
wavelength of 2940 nm in the infrared region. The laser irradiation was performed in a non-contact mode
with a focused beam of (energy density of 155985.96 mJ /cm2, energy of 600 mJ and a PRRs of 6 Hz for
enamel preparation) and (energy density=64994.151 mJ /cm2, energy = 250 mJ and a PRRs=4 Hz for
dentin preparation) with a spot diameter of 0.7mm at 12-15 mm distance and at right angle to the tooth
surface as possible. The histopathological results of the cavities prepared by Er: YAG Laser revealed the
early proliferation of the odontoblasts in the odontoblastic layer of the coronal part of the pulp which led
to the early formation of the reparative dentin in comparison to those prepared by conventional method.
It can be concluded that the use of the Er: YAG laser in class I cavity preparation has proved to be an
efficient technique in comparison to the conventional cavity preparation.
Lying is considered a dangerous tendency among children if it has become a habit. It results in many social problems, such as child’s loss of confidence, lack of others’ respect to him, and his lack of respect to the desired values of the society, such as honesty and trust. Consequently, he will be led to a deviation when he becomes old; especially if the child’s socially unaccepted behavior has not been directed. The research, thus, aims to examine the causes of lying in the most important stage of children’s life; that is, between (4-6) years. Such an aim helps to know about the individual reasons of lying among males and females from teachers’ perspectives. To meet the objective of the study, a number of (128) children
... Show MoreThe effect of 532nm Diode Pumped Solid State (DPSS) laser at power density of 5.234 W/cm2 on the growth of Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus was evaluated. These bacteria were isolated from samples taken from burn and infected wound areas of 55 patients admitted to the burn-wound unit in Al-Kindy teaching hospital in Baghdad during the period from October 2012 to March 2013. Each isolate was identified using microscopic, cultural and biochemical methods. A standard bacterial suspension was prepared for each isolate. Serial dilutions were then prepared and a dilution of 10-5 was selected. Irradiation experiments included four groups: (L-P-) bacterial suspension in saline solution, (L-P+) bacteria
... Show MoreAssimilation is defined ,by many phoneticians like Schane ,Roach ,and many others, as a phonological process when there is a change of one sound into another because of neighboring sounds.This study investigates the phoneme assimilation as a phonological process in English and Arabic and it is concerned specifically with the differences and similarities in both languages. Actually ,this study reflects the different terms which are used in Arabic to refer to this phenomenon and in this way it shows whether the term 'assimilation ' can have the same meaning of 'idgham' in Arabic or not . Besides, in Arabic , this phenomenon is discussed from&nb
... Show MoreThis study was conducted in the Department of Employment and Loans at the Ministry of Labor and Social Affairs to indicate the importance and impact of both the empowerment and the functional flexibility in evaluating the performance of the employees. To achieve the objectives of the study, the data was collected through a questionnaire form designed for this purpose based on previous studies. Data obtained for a significant evaluation of the relationship between the components of both the empowerment and the functional flexibility with the components of the evaluation and determining the degree of importance of each component of both the empowerment and functional flexibility for the components of the evaluation by the extractio
... Show MoreIn this work, an experimental study has been done to expect the heat characteristics and performance of the forced-convection from a heated horizontal rectangular fins array to air inside a rectangular cross-section duct. Three several configurations of rectangular fins array have been employed. One configuration without notches and perforations (solid) and two configurations with combination of rectangular-notches and circular-perforations for two various area removal percentages from fins namely 18% notches-9% perforations and 9% notches-18% perforations are utilized. The rectangular fins dimensions and fins number are kept constant. The fins array is heated electrically from the base
... Show MoreThe results of the current study showed that the thyroid gland in an adult domestic cat (Felis catus) is located in the neck area on both sides of the trachea at rings 1–5. The gland consists of two lobes (right and left), and it is surrounded by a capsule of connective tissue consisting of two outer and inner layers, and a layer of fatty tissue overlaps with the outer layer of the capsule. In addition, the results of this study found that the histological structure of the thyroid gland is composed of several follicles that appear in different sizes and shapes. The follicles are lined with simple cuboidal epithelial tissue and sometimes appear lined with high and low simple cuboidal epithelial tissue. The gland is histologically c
... Show MoreThe results of the current study showed that the thyroid gland in adult domestic cat (Felis catus) is located in the neck area on both sides of the trachea at rings (1-5). The gland consists of two lobes (right and left) and it is surrounded by a capsule of connective tissue consisting of two outer and inner layers, and a layer of fatty tissue overlaps with the outer layer of the capsule. In addition, the results of this study found that the histological structure of the thyroid gland is composed of several follicles that appear in different sizes and shapes; the follicles are lined with simple cuboidal epithelial tissue and sometimes appear lined with high and low simple cuboidal epithelial tissue. The gland is histologically composed of t
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