الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Impressions play a vital role in the success of a prosthesis because a prosthesis can be no more accurate than the impression from which it has been made.
This study was done to assess the dimensional accuracy of the polyether impression material when mixed dynamically using the Pentamix 3 device in comparison with the manually mixing technique.
The impression materials used in this study were Impregum Soft polyether (manually mixed) and Impregum Penta Soft polyether (dynamically mixed). Both materials are monophase medium viscosity using the one step technique.
The master model was made similar to that used in previous studies.(67, 100) It simulated a mandibular arch with four stainless steel abutments in the position of mandibular canines and mandibular first molars. The surface of these abutments were made flat to facilitate measuring the center distances between the abutments thus no reference points were needed providing more accurate measurements.
The measurements done were the anteroposterior, interabutment and cross arch dimensions. Also abutments width and height were measured.
A non-perforated stainless steel tray suitable for the master model was used leaving a regular space between it and the model.
A custom made device was fabricated for holding the tray and the stainless steel model to standardize the passive seating and centering of the tray during impression making with a weight of 1.2 kg(101) to apply the same amount of force during impression making.
Stoppers were applied to the custom device to standardize the seating of the tray during impression making and to uniform the thickness of the impression material.