scholarly journals The Influence of Impression Material on the Accuracy of the Master Cast in Implant Restorations

2018 ◽  
Vol 12 (1) ◽  
pp. 1123-1136
Author(s):  
Spyridon Stefos ◽  
Stefanos Kourtis ◽  
Aspasia Sarafianou ◽  
Panagiotis Zoidis
Keyword(s):  
Horizontal Plane ◽  
Computer Software ◽  
Optical Microscope ◽  
The Other ◽  
Impression Material ◽  
Mean Values ◽  
The Third ◽  
Impression Materials ◽  
Metal Framework ◽  
Medium Viscosity

Aim: The precise framework fit is important for the success of implant restorations. The purpose of the present study was to examine the effect of two different impression materials both of their medium viscosity on the master cast accuracy when parallel and inclined implants were used. Materials and Methods: An epoxy master cast with three implants was fabricated. The first two implants were parallel to each other and perpendicular to the horizontal plane and the third implant had a 250 inclination in reference to the other two. A passively fitting metal framework that was fabricated over this master cast was used to measure accuracy of fit. Five closed tray impressions for each medium viscosity material (polyether and polyvinyl-siloxane) tested were taken and the respective ten stone casts with three implant analogs were fabricated. The metal framework in the master cast, was fixed in the new specimens and the micro-gap between this prosthesis and the implant analogs was evaluated. The specimens were observed to an optical microscope and digital photography. Results and Conclusion: The data were statistically analysed using a computer software and t-test. Polyether exhibited higher micro-gap mean values (93,4 to 61,8 μm) compared to polyvynil siloxane (30,47 to 14,83μm). The differences were statistically significant only for implant B. The categorical regression analysis (p < 0.01) for all implants showed that the marginal micro-gap was affected by the impression material (94.1%) and significantly by the type of it. The micro-gap values were higher for polyether compared to polyvinyl-siloxane. The torqued implant did not exhibit any statistically significant effect.

scholarly journals Elastomeric Impression Materials: A Comparison of Accuracy of Multiple Pours

2011 ◽  
Vol 12 (4) ◽  
pp. 272-278 ◽  
Author(s):  
Dheeraj Kumar ◽  
Anand U Madihalli ◽  
K Rajeev Kumar Reddy ◽  
Namrataa Rastogi ◽  
NT Pradeep
Keyword(s):  
Clinical Significance ◽  
Dimensional Stability ◽  
Central Hole ◽  
Central Incisor ◽  
Impression Material ◽  
Maxillary Central Incisor ◽  
Dimensional Changes ◽  
The Third ◽  
Impression Materials ◽  
Time Periods

ABSTRACT Aim The aim of the present study is to compare the various elastomeric impression materials in terms of accuracy and dimensional stability, with respect to obtaining multiple casts from a single elastomeric impression at various times of pours. Materials and methods Three master dies were prepared for the impression making, two of these were made of brass containing a central hole with undercuts. The third die simulated a conventionally prepared typodont maxillary central incisor. Three elastomeric impression materials were chosen for the study. Each impression was poured at various time periods. Casts thus obtained were evaluated under a traveling microscope to evaluate various dimensional changes. Results Addition silicones provided dies which were shorter in height and bigger in diameter. Polyethers provided dies which were shorter in both height and diameter. Condensation silicones showed insignificant changes from the master die at the immediate pour but deteriorated rapidly after that in subsequent pours. Conclusion None of the impression material showed a consistent behavior up to the fourth pour. They occasionally showed deviation from the pattern, but all these values were statistically insignificant. Polyethers showed lesser ability than both the addition silicones as well as the condensation silicones to recover from induced deformation. Clinical significance Addition silicones as well as the condensation silicones have better ability to recover from induced deformation when compared to polyether. How to cite this article Kumar D, Madihalli AU, Reddy KRK, Rastogi N, Pradeep NT. Elastomeric Impression Materials: A Comparison of Accuracy of Multiple Pours. J Contemp Dent Pract 2011;12(4):272-278.

scholarly journals Viability of Equine Semen Stored in a Polyethylene System for Transport for Eight Hours

2017 ◽  
Vol 45 (1) ◽  
pp. 6
Author(s):  
Alisson Ceccato Maciel ◽  
Vinicius Camargo ◽  
Rodrigo Costa Mattos ◽  
Sandra Fiala Rechsteiner
Keyword(s):  
Plasma Membrane ◽  
Sperm Morphology ◽  
Storage Temperature ◽  
Optical Microscope ◽  
The Other ◽  
Semen Sample ◽  
Cooling Curve ◽  
Control Group ◽  
Mean Values ◽  
Significant Difference

Background: Equine semen storage and shipment, being it colled or frozen, allows the veterinarian to direct matings, providing the use of genetically superior stallions, which are mostly located in breeding stations or training centers. Achieving good pregnancy rates depends, beyond the moment of artificial insemination (AI), on factors related to the semen cooling, such as: system used for transport, cooling rate, final storage temperature, storage time and individual variation among stallions, such as age and resistance to cooling. Based on these aspects, this experiment was conducted in order to test a polyethylene system to ship equine semen.Materials, Methods & Results: A total of 87 ejaculates from five stallions with known fertility were used. The stallions aged between 6 to 14 years old, being three Thoroughbred and two Miniature Pony horse. The ejaculates were collected twice a week using a Hannover artificial vagina. After each collection, the semen sample was macroscopically evaluated for appearance, color and smell. A semen sample was used to evaluate the parameters of total motility, vigor and concentration, being these last three parameters assessed by counting 100 sperm cells for analysis. These analysis were performed using an optical microscope, being the concentration taken with a Neubauer chamber after dilution of 1:20 (semen: citrate formol). Subsequently to this, the semen was diluted 1+1 (diluent+semen) with skim UHT milk, and divided into four aliquots of equal volume, yielding a total of four groups. In the control group (GC) the semen was analyzed immediately after dilution (zero h - 0-h). Samples from other groups were stored for eight h (8-h) in three different devices: Equitainer® (GE), BotuFLEX® (GB) or Polyethylene System - Cooled (SP) and non-Cooled (SPN). During storage of the samples the cooling curve of the system under study was evaluated, using a digital thermometer. To estimate the sperm viability, the parameters of total sperm motility and vigor were evaluated, the integrity of plasma membrane  were evaluated using CFDA / PI, and the plasma membrane functionality using the hiposmotic test (HOST), being also examined the percentage of spermatozoa considered morphologically normal (sperm morphology). The SP showed a PM integrity and sperm morphology as the only parameters that did not occur a statistical difference  when compared to Equitainer® and the BotuFLEX® (averages of the CFDA/PI = 71.12%, 73.29%, 71.32 and averages of morphology = 80.50%, 82.29% and 81.28%, respective values of each parameter to SP, GE and GB, while SPN showed mean values lower than the GC and GE for all parameters (averages of total motility = 50.65% and 62, 60%; averages of vigor = 1.78 and 2.43; averages of CFDA/PI = 72.56% and 78.30%; averages of HOST = 43.56% and 48.87%; averages of morphology = 77.17% and 84.82%, respectively for SPN and GE). Compared to BotuFLEX®, the SPN had no significant difference only for the parameter of PM functionality (HOST).Discussion: The average temperature of SP was 18.0°C, and the SPN was 18.2°C. The SP was equal or similar to the other used systems, but the SPN showed no difference when compared to PS. However NPS was worse than the other systems from this experiment. These results show that the PS might be an alternative to ship equine semen for eight h, compared to the other cooled systems studied in this work.

scholarly journals EVALUATION OF ACCURACY OF TWO DIFFERENT IMPRESSION MATERIALS AND THREE DIFFERENT IMPRESSION TECHNIQUES ON THE VERTICAL MISFIT OF A THREE UNIT IMPLANT SUPPORTED FIXED DENTURE PROSTHESES

2020 ◽  
Vol 6 (1) ◽  
pp. 15-20
Author(s):  
Debajyoti Sarkar ◽  
Shitij Srivastava ◽  
Abhinav Shekhar ◽  
Amrita Jayaswal ◽  
Love Bhatia ◽  
...  
Keyword(s):  
The Other ◽  
Marginal Gap ◽  
Impression Material ◽  
Impression Technique ◽  
Other Hand ◽  
Impression Materials

AIM: The aim of the study is to evaluate the accuracy of two different impression materials and three different impression techniques on the vertical misfit of a three-unit implant supported fixed denture prostheses.Materials and Methods: A total of 60 casts were fabricated for the present study with a closed tray, open tray and open tray splinted abutment impression technique. Two different commercially available impression materials were used - polyether and addition silicone. Both the materials were used for all the above impression techniques.Results: Accordingtotheresultderivedfromthisstudypolyethershowedleastmarginalgap.On the other hand on the basis of impression techniques open tray impression with splinted transfer coping also exhibited a minimum marginal gap.Conclusion: 1. Higher marginal accuracy was found in impressions made by polyether compared to polyvinyl siloxane. 2. Open tray splinted technique exhibited a minimum marginal gap when used with polyether as impression material compared to open tray non splinted technique and closed tray technique.

scholarly journals A New Horizontal Plane of the Head

2018 ◽  
Vol 6 (5) ◽  
pp. 767-771 ◽  
Author(s):  
Ehab El Kattan ◽  
Mohamed El Kattan ◽  
Omnia A. Elhiny
Keyword(s):  
Soft Tissue ◽  
Horizontal Plane ◽  
Head Position ◽  
The Other ◽  
Reference Plane ◽  
Head Orientation ◽  
Mean Values ◽  
The Subject ◽  
Frankfurt Horizontal ◽  
Frankfort Horizontal Plane

AIM: This study aimed to attempt to introduce a new extracranial horizontal plane of the head (K plane that extends from SN to SAE bilaterally) that could act as a substitute to the Frankfurt horizontal intracranial reference plane; both clinically and radiographically.MATERIAL AND METHODS: The new K plane depended on three points of the head. The first was the soft tissue nasion (NS) on the interpupillary line when the subject looked forward at a distant point at eye level. The other two points were the superior attachments of the ears (SAE).RESULTS: The student “t” test comparing mean values of K/V and FH/V was not significant; -0.21.  The coefficient of correlation between different variables was highly positively significant (r = 0.98 with probability = 0.001).CONCLUSION: Within the limitations of this prospective study, the new K plane was found to be both reliable and reproducible. It can be used as a reliable reference plane instead of Frankfort horizontal plane both clinically and radiographically; as it is an accurate tool for head orientation in the natural head position.

scholarly journals Comparative Analysis of Dimensional Precision of Different Silicone Impression Materials

2011 ◽  
Vol 12 (3) ◽  
pp. 208-215 ◽  
Author(s):  
Bader K Al-Zarea ◽  
Mohamed G Sughaireen
Keyword(s):  
Comparative Analysis ◽  
Optical Microscope ◽  
Three Dimensions ◽  
Time Interval ◽  
Impression Material ◽  
Dimensional Precision ◽  
Impression Technique ◽  
Impression Materials ◽  
Significant Difference ◽  
Over Time

ABSTRACT Objectives To investigate the accuracy of four commercial types of additional silicone impression materials (AFFINIS®, Virtual®, Relay 2002 CD® and Silagum®). Materials and methods The accuracy of impression material was measured indirectly by measuring three dimensions on stone cast poured from impressions of a stainless steel master model. The three dimensions on stone cast were measured at 1 hour, 2 days, 1 and 2 weeks after making the impression. Two impression techniques were used in the current study. The two-step impression technique was used for AFFINIS® and Virtual®, while single-step technique was used for Relay 2002 CD® and Silagum® materials. Twenty impressions were made of the master cast at four different periods for each of the tested four materials with a total of 320 impressions. Two vertical dimensions and one horizontal dimension were measured on master cast using optical microscope. Statistical analysis was run to compare the mean measurements for tested casts from each impression and time interval with the master cast. Results No statistical significant differences were found (p > 0.05) in the accuracy of tested materials. There was no significant difference of master cast and impression cast means over time. Additionally, impression technique could be correlated with accuracy. Conclusion The tested additional silicones showed accuracy over time and they could be delayed up to 4 weeks duration without any significant changes in its dimensional stability. Silagum® impression material was the most accurate followed by Relay 2002 CD®, Virtual® and AFFINIS®. Clinical significance Silagum® impression material is most accurate followed by Relay 2002 CD®, Virtual® and AFFINIS®. How to cite this article Al-Zarea BK, Sughaireen MG. Comparative Analysis of Dimensional Precision of Different Silicone Impression Materials. J Contemp Dent Pract 2011; 12(3):208-215.

scholarly journals Comparison of Some Mechanical and Physical Properties of three Types of Impression Materials with Different Dental Implant Angulations

2018 ◽  
Vol 11 (3) ◽  
pp. 1359-1368
Author(s):  
Dhuha H. Mohammed ◽  
Abdalbseet A. Fatalla ◽  
Ghassak H. Jani
Keyword(s):  
Contact Angle ◽  
Dimensional Accuracy ◽  
Mean Value ◽  
Distance Measurements ◽  
Tear Strength ◽  
Impression Material ◽  
Mean Values ◽  
Impression Materials ◽  
Linear Distance ◽  
Significant Difference

Choosing an appropriate impression material is a challenge for many dentists, yet an essential component to provide an excellent clinical outcome and improve productivity and profit. The purpose of present study was to compare wettability, tear strength and dimensional accuracy of three elastomeric impression materials, with the same consistencies (light-body). Three commercially available light body consistency and regular set 3M ESPE Express polyvinylsiloxane (PVS), 3M ESPE Permadyne polyether (PE), and Identium (ID), impression materials were comparedTear strength test, contact angle test and linear dimensional accuracy were evaluated for three elastic impression material. Among the three experimental groups PE impression material exhibited the higher mean values of tear strength, followed by ID group then PVS which showed the lowest mean value. For wettability test, Polyether group exhibited the lowest mean values of contact angle, followed by mean values of contact angle of ID group, while the PVS group showed the highest contact angle. There was a significant difference in the linear distance measurements between the two parallel impression coping/analogue assembly of the working models obtained by using (Identium, 3M ESPE ExpressPVS , 3M ESPE Permadyne polyether) the polyether impression materials provide higher tear strengths and lower wettability than elastomer impression materials and Identium material have acceptable tear strengths and wettability. All three experimental impression materials were distorted in both conditions (angled and parallel implant situations)

Efficacy of some insecticide modules against major insect pests and spider population of rice, Oryza sativa L.

ENTOMON ◽  
2018 ◽  
Vol 43 (4) ◽  
pp. 257-262
Author(s):  
Atanu Seni ◽  
Bhimasen Naik
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Untreated Control ◽  
Insect Pests ◽  
Oryza Sativa L ◽  
Gall Midge ◽  
Stem Borer ◽  
The Other ◽  
The Third ◽  
Treated Plot

Experiments were carried out to assess some insecticide modules against major insect pests of rice. Each module consists of a basal application of carbofuran 3G @ 1 kg a.i ha-1 at 20 DAT and Rynaxypyr 20 SC @ 30 g a.i ha-1 at 45 DAT except untreated control. All modules differ with each other only in third treatment which was applied in 65 DAT. The third treatment includes: Imidacloprid 17.8 SL @ 27 g a.i ha-1, Pymetrozine 50 WG @ 150 g a.i ha-1, Triflumezopyrim 106 SC @ 27 g a.i ha-1, Buprofezin 25 SC @ 250 g a.i ha-1; Glamore (Imidacloprid 40+Ethiprole 40% w/w) 80 WG @ 100 g a.i. ha-1, Thiacloprid 24 SC @ 60 g a.i ha-1, Azadirachtin 0.03 EC @ 8 g a.i ha-1, Dinotefuran 20 SG@ 40 g a.i ha-1 and untreated control. All the treated plots recorded significantly lower percent of dead heart, white ear- head caused by stem borer and silver shoot caused by gall midge. Module with Pymetrozine 50 WG @ 150 g a.i ha-1 treated plot recorded significantly higher per cent reduction of plant hoppers (>80% over untreated control) and produced higher grain yield (50.75 qha-1) than the other modules. Among the different treated modules the maximum number of spiders was found in Azadirachtin 0.03 EC @ 8 g a.i ha-1 treated module plot followed by other treatments.

Retroaktive Neuverhandlung

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Daniel Martin Feige
Keyword(s):  
Original Work ◽  
The Other ◽  
Final Part ◽  
Critical Reading ◽  
The Third ◽  
Works Of Art ◽  
The Relationship

Der Beitrag widmet sich der Frage historischer Folgeverhältnisse in der Kunst. Gegenüber dem Gedanken, dass es ein ursprüngliches Werk in der Reihe von Werken gibt, das späteren Werken seinen Sinn gibt, schlägt der Text vor, das Verhältnis umgekehrt zu denken: Im Lichte späterer Werke wird der Sinn früherer Werke neu ausgehandelt. Dazu geht der Text in drei Schritten vor. Im ersten Teil formuliert er unter der Überschrift ›Form‹ in kritischer Abgrenzung zu Danto und Eco mit Adorno den Gedanken, dass Kunstwerke eigensinnig konstituierte Gegenstände sind. Die im Gedanken der Neuverhandlung früherer Werke im Lichte späterer Werke vorausgesetzte Unbestimmtheit des Sinns von Kunstwerken wird im zweiten Teil unter dem Schlagwort ›Zeitlichkeit‹ anhand des Paradigmas der Improvisation erörtert. Der dritte und letzte Teil wendet diese improvisatorische Logik unter dem Label ›Neuaushandlung‹ dann dezidiert auf das Verhältnis von Vorbild und Nachbild an. The article proposes a new understanding of historical succession in the realm of art. In contrast to the idea that there is an original work in the series of works that gives meaning to the works that come later, the text proposes to think it exactly the other way round: in the light of later works, the meanings of earlier works are renegotiated. The text proceeds in three steps to develop this idea. Under the heading ›Form‹ it develops in the first part a critical reading of Danto’s and Eco’s notion of the constitution of the artworks and argues with Adorno that each powerful work develops its own language. In the second part, the vagueness of the meaning of works of art presupposed in the idea of renegotiating earlier works in the light of later works is discussed under the term ›Temporality‹ in terms of the logic of improvisation. The third and final part uses this improvisational logic under the label ›Renegotiation‹ to understand the relationship between model and afterimage in the realm of art.

Features of the course and treatment of glaucoma during pregnancy

2020 ◽  
Vol 98 (3) ◽  
pp. 178-184
Author(s):  
T. V. Chernyakova ◽  
A. Yu. Brezhnev ◽  
I. R. Gazizova ◽  
A. V. Kuroyedov ◽  
A. V. Seleznev
Keyword(s):  
Pregnant Women ◽  
Laser Treatment ◽  
Progressive Disease ◽  
Clinical Course ◽  
The Other ◽  
Third Trimester ◽  
The Third ◽  
Chronic Progressive Disease ◽  
Hypotensive Therapy ◽  
Eye Pressure

In the review we have integrated all up-to-date knowledge concerning clinical course and treatment of glaucoma among pregnant women to help specialists choose a proper policy of treatment for such a complicated group of patients. Glaucoma is a chronic progressive disease. It rarely occurs among childbearing aged women. Nevertheless the probability to manage pregnant patients having glaucoma has been recently increasing. The situation is complicated by the fact that there are no recommendations on how to treat glaucoma among pregnant women. As we know, eye pressure is progressively going down from the first to the third trimester, so we often have to correct hypotensive therapy. Besides, it is necessary to take into account the effect of applied medicines on mother health and evaluate possible teratogenic complications for a fetus. The only medicine against glaucoma which belongs to category B according to FDA classification is brimonidine. Medicines of the other groups should be prescribed with care. Laser treatment or surgery may also be a relevant decision when monitoring patients who are planning pregnancy or just bearing a child. Such treatment should be also accompanied by medicines.

The Nile Delta during the Early Dynastic and Old Kingdom periods. Preliminary remarks on the evolution of settlement landscape

2020 ◽  
pp. 13-61
Author(s):  
Natalia Małecka-Drozd
Keyword(s):  
Nile Delta ◽  
Ancient Egypt ◽  
The Other ◽  
Old Kingdom ◽  
The Third ◽  
Other Hand ◽  
Early Dynastic ◽  
Territorial Structure ◽  
Settlement Landscape ◽  
New Settlements

The 3rd millennium BC appears to be a key period of development of the historical settlement landscape in ancient Egypt. After the unification of the country, the process of disappearance of the predynastic socio-political structures and settlement patterns associated with them significantly accelerated. Old chiefdoms, along with their centres and elites, declined and vanished. On the other hand, new settlements emerging in various parts of the country were often strictly related to the central authorities and formation of the new territorial administration. Not negligible were climatic changes, which influenced the shifting of the ecumene. Although these changes were evolutionary in their nature, some important stages may be recognized. According to data obtained during surveys and excavations, there are a number of sites that were considerably impoverished and/or abandoned before and at the beginning of the Old Kingdom. On the other hand, during the Third and Fourth Dynasties some important Egyptian settlements have emerged in the sources and begun their prosperity. Architectural remains as well as written sources indicate the growing interest of the state in the hierarchy of landscape elements and territorial structure of the country.

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