Background: This clinical trial aims to evaluate the color changes of direct resin composite veneer (DCV) restorations based on spectrophotometric analysis of 4 different types of resin composites between the baseline immediately after polishing and after one year of follow-up. Materials and methods: 28 patients were assessed for eligibility for participation, aged between 18 and 38 years old, who indicated for DCV restorations in anterior maxillary teeth were considered for participation in this study. In total, 25 patients who met the inclusion criteria were selected (6 males and 19 females, mean age: 20.9 at the time of restoration placement), and 3 patients were excluded. Participants were divided into four groups based on the type of composite resin used for restorations. Group 1 nanohybrid Ips Empress direct (Ivoclar Vivadent)](IPS) (13 restorations/6 patients), group 2 microfilled [Essentia (GC cooperation Japan)](ES) (14 restorations / 7 patients), group 3 supra-nano filled [ Estelite ∑ Quick (Tokuyama, Tokyo, Japan)](EQ) (17 restorations / 7 patients) and group 4 nanofill [Filtek Ultimate (3M ESPE)](FU) (13 restorations / 5 patients). Baseline Color measurements were performed with a spectrophotometer immediately after finishing and polishing (baseline), and after one year of recall, color change (ΔE) from baseline values and after one year of follow-up of DCVs were calculated according to CIELab color coordinates. For this, a silicone mold was fabricated for each patient and used as a guide for each measurement to standardize the site of the readings. Statistical analysis of the data was applied using the Kruskal-Wallis test with Dunn-Bonferroni posthoc test after controlling the distribution of data in terms of normality with the Shapiro Wilk test. Results: At the end of one year,25 participants(57restorations) were followed up. The mean ΔE of IPS, EQ, and FU composites were higher than the ES composite resin, but there was no statically significant difference between all types of composites (P> 0.05). There was no statistically significant difference in the mean ΔL* between any types of composite resin (p> 0.05). There was a significant change in Δa* and Δb* after a one-year recall for all the types of DCV restorations (p < 0.05). Conclusion: After one year of follow-up, the spectrophotometer measurements of direct resin composite veneer restorations, it was concluded no difference between the mean ΔE of ES, IPS, FU, and EQ resin composite. ES (Microfilled hybrid) showed a lower mean ΔE value compared to the other groups. All groups of resin composite showed color changes within clinically acceptable levels after a one-year follow-up.
Aromaticity reversals between the electronic ground (S0) and low-lying singlet (S1, S2) and triplet (T1, T2, T3) states of naphthalene and anthracene are investigated by calculating the respective off-nucleus isotropic magnetic shielding distributions using complete-active-space self-consistent field (CASSCF) wavefunctions involving gauge-including atomic orbitals (GIAOs). The shielding distributions around the aromatic S0, antiaromatic S1 (1Lb), and aromatic S2 (1La) states in naphthalene are found to resemble the outcomes of fusing together the respective S0, S1, and S2 shielding distributions of two benzene rings. In anthracene, 1La is lower in energy than 1Lb, and as a result, the S1 state becomes aromatic, and the S2 state becomes anti
... Show MoreThis research tackles the play of Synge "Rider to the Sea" to find out whether the
theories of Leech (1983) and Brown and Levinson (1987) can be applied or not to this study.
The model of Leech (1983) consists of seven principles and for Brown and Levinson
(1987),it consists of two principles of politeness where one of them is positive and the other is
negative politeness.
It is hypothesed that:
1. There is a relation between the two theories.
2. Synge deals with these theories in such a way to depict his characters.
3. It is also hypothesed that every character deals with these principles in such a way to show
the events of the play.
The study concludes that there is a relation between the two theories in d
The ethyl acetate synthesis via heterogeneous reactive distillation is studied experimentally using ethanol and acetic acid. Three types of cation exchanging resins were used as catalysts: Zerolit 225, Zerolit 226 and Ambylite 400. Experiments were carried out in two units of the same dimensions. Each unit consisted of three sections: rectifying, reactive and stripping sections of heights (60+25+20) cm respectively and 2.5cm column diameter. The first unit (column-A-) was a fractionation type and the second unit (column-B-) was packed column. The packing type was hollow glass cylinders with 10 mm height, and 4, 5 mm inner and outer diameter respectively.
The experiment
... Show MoreAbstract
The research aims to verify the dimensions of tax justice that exist in Iraq, and to determine their impact on tax compliance. Through a revised model of tax justice based on the literature of tax justice according to the classification of the studies of (Saad, 2009), (Wenzel, 2002), by using a questionnaire as an experimental measurement tool designed to be in line with perceptions of tax justice in Iraq. To define the dimensions of tax justice (the independent variable) with eight dimensions (Distributive justice, Exchange justice, Vertical justice, Horizontal justice, Retributive justice,
... Show MoreBackground: Laparoscopic surgery for
appendicitis is now a well established and
advanced method of performing general surgical
procedures.
Objectives: To compare the outcome of
laparoscopic and open appendectomies in terms
of operative time, analgesic requirement,
postoperative complications, hospital stay, return
to normal activity and condition of scar.
Methods: This prospective study was carried
out from 1stMay 2008-1st January 2010, involving
110 patients (45 male and 65 female) with
features suggestive of acute appendicitis were
divided into 45 patients laparoscopic
appendectomy (LA) group and 65 patients open
appendectomy (OA) group, after taking informed
consent. LA was done with the
Thethesis of theresearch is to deal with relations between Russia and Yemen after 2011.That relationwas significant in different fields, historic, economic, strategic and cultural ones. There are mutual interestsbetweenRussia and Yemen, especially with the economic development and growth in Russia as an important partner to Yemen.Their has to an a great deal of progress in different types of relations, where as they were only partner in military relations. The studywasclassifiedintoto three sections: the first section dealt with strategic importance of Yemen to Russia. And second section dealt withthe military factor between Russia and Yemen. While the third section dealt with the economic factor between Russia and Yemen. In addi
... Show MoreDiscourse markers are expressions used to connect sentences to what comes before or after and indicate a speaker's attitude to what he is saying.As linguistic items, they have important functions in discourses of various styles or registers. And being connective elements, discourse markers relate sentences, clauses and paragraphs to each other. "One of the most prominent function of discourse markers, however, is to signal the kinds of relations a speaker perceives between different parts of the discourse". (Lenk 1997: 2) Through political discourse, different types of discourse markers are used. This paper deals with the importance and functions of discourse markers and tries to shed light on the kinds of discourse markers used in polit
... Show MoreIn thisipaper, we introduce the concepts of the modified tupledicoincidence points and the mixed finiteimonotone property. Also the existenceiand uniquenessiof modified tupled coincidenceipoint is discusses without continuous condition for mappings having imixed finite monotoneiproperty in generalizedimetric spaces.
This research attempted to take advantage of modern techniques in the study of the superstructural phonetic features of spoken text in language using phonetic programs to achieve more accurate and objective results, far from being limited to self-perception and personal judgment, which varies from person to person.
It should be noted that these phonological features (Nabr, waqf, toning) are performance controls that determine the fate of the meaning of the word or sentence, but in the modern era has received little attention and attention, and that little attention to some of them came to study issues related to the composition or style Therefore, we recommend that more attention should be given to the study of
The current research aims to identify the occupational stresses of doctors who are working in governmental hospitals according to the variables of gender and career ranking. The researcher adopted a scale to measure the occupational stress of (1088) doctors (561 males and 527 females) working in governmental hospitals. The results have shown that doctors have a high level of professional stress, but there is no significant difference between doctors in terms of gender. However, there were significant differences in favor of novice residents.