Evaluation of the accuracy of impression in removable partial denture when using multiple viscosities in single impression versus one viscosity in single impression

Research Abstract

Evaluate edition accuracy for partial dens using multiple viscosities in one edition versus one viscosity in one edition Arabic Summary This study was conducted to evaluate the dimensional accuracy of three different viscosities of measuring materials (polyvinylsiloxane), which are light, medium, and heavy viscosities, on an ideal model of a partially toothless mould. The perfect dimensional mold was chosen, the Kennedy Division II and one variant of acrylic. A tray was made on the acrylic mold with fixed pillars so that it returns to the same place every time the size is taken. The reference points were placed in the form of small balls on the mold before taking measurements and pouring them to serve as a reference for measuring the length and width. Four groups of materials have been classified according to viscosity. They are used as follows: The first group: Ten measurements of the acrylic mold using light viscosity The second group: Ten measurements of the acrylic mold using the medium viscosity The third group: Ten measurements of the acrylic mold using heavy viscosity Fourth group: Ten measurements of the acrylic mold using the three viscosities together in the same tray The measurements were made using two methods The first method is using a digital device capable of measuring the accuracy of the print with an accuracy of up to 0.01 of a millimeter The second method: The templates were photographed by a digital camera and transferred to the computer and inserted into a special program for measurements, and all measurements were made as in the first method, but using the computer. And using a special program, the images were converted into three-dimensional images and the dimensions were calculated by matching the images. The results were collected and statistically analyzed, and the following conclusions were drawn from the study: First: the casting obtained from the medium viscosity is more accurate in dimensions than that used with other viscosities. Second: When the three viscosities were used together in one tray it produced less accurate mold than that obtained from medium viscosities alone, however it was more accurate than light viscosities and heavy viscosities when each viscosity was used separately. Third: The first and second measurement methods are similar in dimensional accuracy Fourth: The method of measurement by matching images of 3D models is more accurate and easy in terms of ease of collecting, saving and calculating data and less time wasting compared to the first method, in addition to the possibility of easily retrieval of information later.

Research Keywords

Evaluation of the accuracy of impression in removable partial denture when using multiple viscosities in single impression versus one viscosity in single impression