The Assessment of Time and Storage Environment Effects on Dimensional Changes of Two Types of Acrylic Resin Post Patterns GC and Reliance

 The purpose of this laboratory study was to investigate and compare the magnitude of the dimensional changes observed in the acrylic patterns under the influence of different times and conditions of storage.
Materials &

 This study was an experimental study. The sample number was 28 in 4 groups (7 samples each group). The resulting paste of acrylic samples was placed inside a metal mold and after setting time with the slightest of deformations it was removed. Using this method 28 samples were prepared for each material. The diameter of samples was then measured immediately using the digital caliper with a precision of 0.01 mm. The samples were then divided into four quadruple groups and stored at 22° C room temperature, 22° Cat water, Dry 4° C environment and 4° C water. The dimensions of the four groups were measured at intervals of 1, 8, 24, and 48 hours after polymerization and being removed from the metal molds. Data analysis was done with SPSS 24 software (p value = 0.05). The MANOVA test was used for data analysis.

 The findings of the current study showed that the dimensional changes of Duralay and GC acrylic resins at both 4 and 22° C in dry and water environments are decreasing over time (p value < 0.001). this study indicated that the contraction rate of two types of acrylic resins, Duralay and GC, at two temperatures of 4 and 22° C, and dry and humid conditions and at various times were not different. 

 dimensional changes in of the two types of acrylic resin, Duralay and GC, during the lapse, the procedure is going to be decreased but have not seen any statistical difference between these type of acrylic resin in environment storage.