Background: The displacement of artificial teeth during complete denture construction presents major processing errors in the occlusal vertical dimension which were verified at the previous trial denture stage. The aim of this study was to assess the effect of delay in processing after final flask closure and tension application on the vertical acrylic and porcelain teeth displacement of complete dentures constructed from heat cured acrylic and the results were compared with the conventional processing method. Materials and methods: forty samples of identical maxillary complete dentures were constructed from heat polymerized acrylic resin. These samples were subdivided into the following experimental subgroups in which each subgroup contains 5 samples for both acrylic and porcelain teeth and as follows: 1. Conventional flasking technique and immediate processing. 2. Conventional flasking technique and 6 hours delay in processing. 3. flasking technique with tension system and immediate processing. 4. flasking technique with tension system and 6 hours delay in processing. Reference metal pins were attached to the middle of the buccal surface of the upper right canine and center of the buccal groove of the left first molar. And according to these reference points on the teeth another metallic Reference pins were fixed on the denture vestibules and at a distance of 7.5mm by straight lines and 6.5mm where placed between the metal pins and the vestibules in order to standardize the measurement. The distance between the right and left metal pins on the canine and molars and the corresponding metal pins on the buccal vestibules were measured during the wax up stage and after processing by using an optical travelling microscope with an accuracy of 0.0005 mm. Means in (mm) were analyzed statistically by analysis of variance and the comparative T-test and least significance test (LSD). Results: Significant reduction in vertical displacement of the teeth occurred in groups when 6 hours delay in processing were applied, but a significant improvement was also observed in groups with tension system application when compared with control group. On the other hand, there were a high significant reduction in the vertical displacement in groups with tension system and 6 hours delay in processing combination. While for the type of artificial teeth data showed significant difference in the amount of vertical displacement of the teeth in groups with acrylic teeth when compared with porcelain teeth. Conclusions: The findings of this study showed that 6 hours delay in processing and tension system application were effective in reducing the vertical displacement of the artificial teeth during flasking. The maximum reduction in the displacement was observed in dentures constructed from acrylic teeth. On the other hand, significant decrease in vertical displacement of the teeth was detected in dentures constructed from porcelain teeth.
In this paper, we estimate the survival function for the patients of lung cancer using different nonparametric estimation methods depending on sample from complete real data which describe the duration of survivor for patients who suffer from the lung cancer based on diagnosis of disease or the enter of patients in a hospital for period of two years (starting with 2012 to the end of 2013). Comparisons between the mentioned estimation methods has been performed using statistical indicator mean squares error, concluding that the survival function for the lung cancer by using shrinkage method is the best
In this paper, we define a cubic bipolar subalgebra, $BCK$-ideal and $Q$-ideal of a $Q$-algebra, and obtain some of their properties and give some examples. Also we define a cubic bipolar fuzzy point, cubic bipolar fuzzy topology, cubic bipolar fuzzy base and for each concept obtained some of its properties.
Fine art represents part of society's culture. The development of art was accompanied by the penetration of new worlds known as the fourth dimension. After art entered the boundaries of geometry and reduction; He began to break into the absurd, and the form and philosophy of art changed, moving from modernity to what came after it to contemporary. Transforming from a formal form into a symbolic form with philosophical implications linked to the light, audio and kinetic effects as they embody time, the concept became the master of the idea. The research aims to identify the concept of time and its types, then the philosophical concept of time and its reflection on contemporary art, through the analytical study of a selection of contempora
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The term “non-violence” is a means of political, social, and advocacy that excludes force in reaching its objectives, and lacks infringement of the rights of non-violence. The policy of non-violence is a beautiful logic of the whole of Islamic creation, in that it is an integral part of the whole structure of Islam and it is a policy of brilliant and brilliant saying in the Almighty: `` Neither level nor good or bad, pay what is better, If that between you and him enmity as if he were intimate guardian (Suratvsalat, verse: 34. Has According to the prophet of Islam, it means that God gives to kindness (kindness) what does not give to violence (Sunan Abu Dawood, 4/255). These terms accurately communicate what is meant by violence and n
... Show MoreCeramics type Yttrium oxide with Silicon carbide. were selected to investigate its sintered density, microstructure and electrical properties, after adding V2O5, of 100 nm grain size. Different weight percentages ranging from (0.01,0.02,0.03 and 0.04) were used. Dry milling applied for twelve hours. The pelletized samples were sintered at atmospheric of static air and at sintering temperature 1400 ˚C, for three hours. The crustal structure test shoes the phase which is yttrium silicon carbide Scanning electron microscopy, scan sintered microstructure. Samples after sintering were electrically investigated by measuring its capacitance, dielectric constant and their results showed increasing after added V2O5 particles at the combinat
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