Background: An accurate adaptation of the crown to the finish line is essential to minimize cement dissolution and to preserve periodontium in fixed partial denture cases. An accurate adaptation of crown is possible only when preparation details are captured adequately in the impression and transferred to cast. For these reasons, gingival displacement is necessary to capture subgingival preparation details.The aim of the present study is to measure in vivo the horizontal displacement of the gingival sulcus obtained by using three new cordless retraction materials (Magic Foam Cord®, Racegel and Astringent Retraction Paste) in comparison to medicated retraction cord. Materials and method: Thirty-two patients requiring porcelain fused to metal fixed partial denture for replacement of a missing maxillary posterior tooth (either one of thepremolars or the first molar). The patients are randomly divided into four groups of eight patients each according to the type of gingival retraction material used as follows: Group I: Medicated retraction cord (racemic epinephrine hydrochloride 0.3 ± 0.2 mg per inch of cord, #00), Group II: Magic Foam Cord® (expanding polyvinyl siloxane), Group III: Racegel (25% aluminum chloride gel) and Group IV: Astringent Retraction Paste (15% aluminum chloride paste). Three depth orientation grooves were prepared in the buccal and palatal surfaces of a maxillary premolar parallel with the long axis of the tooth, extending from the middle third to the gingival third with the level of the free gingiva using a flat-ended diamond fissure bur. Impression of the gingival sulcus was then made using monophase polyether impression material (Impregum™ Penta™ Soft, 3M ESPE, Germany), before and after gingival retraction with either of the aforementioned gingival retraction materials. The sulcus width, before and after gingival retraction was measured on the master cast (in µm), after its sectioning longitudinally bucco-palatally at the middle of the prepared grooves using a rotary diamond disc. The measurement carried out by using digital microscope (Dino-Lite)at a magnification of 230X. The horizontal gingival displacement (the distance from the end of each prepared groove to the crest of the gingiva) measured by subtracting the gingival sulcus width after retraction from that before retraction. Results: The findings of the present study showed that the highest mean of horizontal gingival displacement is recorded by Group IV (Astringent Retraction Paste) (250.7900 µm), whereas the lowest mean of horizontal gingival displacement is recorded by Group III (Racegel) (78.0988 µm). One-way ANOVA test showed statistically highly significant differences among groups (p< 0.01). Least Significant Difference test (LSD test) was also used to make multiple comparisons among groups and revealed a statistically highly significant difference between each two groups (p< 0.01). Conclusion: The two new gingival retraction pastes (Astringent Retraction Paste and Magic Foam Cord®) could be used for gingival retraction as alternatives to medicated retraction cord. They offer advantages of simplified placement technique and shorter application time with greater gingival retraction. Meanwhile, the use of Racegel alone is not recommended for gingival retraction since it provides the least gingival displacement.
At the last two decades , The environment has witnessed tremendous changes in many fields with the huge competition , various technological development and customer satisfaction , that are reflected in economic units a doption for lean production system.
Lean accounting that has appeared as a response for change occurred of economic units adoption for changes occurred of economic units adoption for lean production instead of wide production system , has devised new performance measures suitable for economic units adoption for lean ideas: and helping in providing suitable information about evaluating economic unit performance , these measures are divided into three levels , cell level,value flow level , a
... Show More- The problem of infertility considers one of the chronic problem a which faced the
individual & families equally . This problem causes a negative effects in psychological ,
social and development fields. The infertility contributes in weakening the human
development, when the human development has become as a centre point which centered
about individual preparing , rehabilitation, training and knowledge toreach to the required
excellence.
We think that , the infertility destroys the socially development; therefore the socially and
scientific institutions are working hard to find successful solution to resolve the problem
infertility through sophisticated and scientific methods. This problem
In this paper the queuing system (M/Er/1/N) has been considered in equilibrium. The method of stages introduced by Erlang has been used. The system of equations which governs the equilibrium probabilities of various stages has been given. For general N the probability of j stages of service are left in the system, has been introduced. And the probability for the empty system has been calculated in the explicit form.
Bending effects on the transmission of optical signal are investigated on a single mode
optical fiber (SMOF) of 10 m length, core radius of 5 μm and optical refractive index difference
0.003. The bending radii (R) were between 0.08 and 0.0015 m. A great decrease in the amplitude is
shown for radii below 0.01 m. Sudden break down occurs for radii less than 0.0015 m. Birefringence
(B) is difficult to measure for long fibers. Meanwhile, B was found by comparing with calibrated
fiber of the same properties but of length of 0.075 m. The results show an increase in propagation
constant (Δβ) and the decrease in beat length (Lb), and show that bending decreases the critical radius
of curvature (Rc) related to B. The chang
Jurists were unable to comprehend modern terminology and concepts to provide mature answers
On the questions and issues of the age, and what I want to research and raise it; an important and urgent subject, to crystallize the opinion jurisprudence
Islamic, which is the subject of citizenship. The globalization of the concept of citizenship, and the spread of special cultural differences,
The blurring of the identities and specificities of nations due to conflict, or political differences, often results in responses
This trend is inversely rooted and rooted, and as a result, the threat to one's religion or predecessors becomes threatened by one's culture,
Thus destroying the essence of his identity. Man has the highest rank
(1)
The expressive speech in the art of acting is considered to be the leading action for thinking and the interior interaction of the individual, in the organization of his relationship with the elements of the environment and its content, and the more acquired the individual's performance today skills in organizing and export of his conflicts and natural occasions , whenever , becomes more adaptable and an interpreted physically and acoustically inside pluralities in personalities, suited to the modern age. This research has addressed a range of topics related to expressive speech in the art of acting, since the first chapter included a systematic framework of the research, represented by the problem , the importance and aims of research t
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Research summary
Praise be to God, and prayers and peace be upon our master Muhammad, his family and companions until the Day of Judgment.
As for after:
It is the right of every nation to take care of its scientific heritage, and to reveal its human civilizational impact, and the Arabs are the richest nations in heritage, as they had in every period of time a sign and pride, the Arabs fulfilled their duty towards humanity, and they carried out a large part of their scientific activity towards humanity.
Therefore, highlighting some of the scientific aspects of the civilized activity of the Arabs, and removing some of the illusions spread by some malicious people, is a human duty before it is a national duty.
... Show MoreThis study is based on the basic idea: that human communication does not stop at the limits of words spoken, but extends to include the movements of the body and its members, such as the face, hand, eye, hearing, touch, taste, sensation and the public body.
The human movements represented by polarization, frowns, tattoos, and movements are all auxiliary tools that reach meanings and affect others greatly.
Perhaps their importance is also in their ability to translate what is going on in the soul, and to show it to the outside body members, without the control of the human in many cases, it is thus an important factor in the process of human communication.
The purpose of this study is to show the senses of the senses in the
In order to get an idea about things closely, we should look at the role of social discipline
in the building of society from civilization cultural viewpoint. The real weigh of the societal
opinion is not measured by the number of its population or its area but the real value lies in its
civilization cultural accumulative experience inherited by the generations, which determine its
distinguished character. That is based upon the social construction in which the methods of
socialization and political, economic, cultural and religious stability and enhance the national
and ethical character of self-realization.
In this research, we try to give an analysis for the obstacles in political economic and
religious social