Influence of tray type and different hardness of polyvinyl siloxane impression materials on the dimensional accuracy of dental implant impression

Abstract

Dimensional accuracy is essential for the accurate construction of a dental implant impression. Materials used for taking an impression to play a significant role in producing an accurate implant impression. The present study was an evaluation of the dimensional accuracy of master casts obtained using different hardness impression materials and different trays with a closed tray impression technique. An acrylic master model of the lower dental arch with four parallel implant analogues was fabricated, and 90 implant impressions were made. Three groups (n= 30) were experimented using three different Polyvinyl Siloxane impression materials. Three types of impression trays were used, the first one was (self-cure acrylic) custom tray, and the other two were (plastic and metal) stock trays. The inter implant distances were measured on master casts using a digital microscope. Different hardness results were found, Mean and SD for Panasil (heavy body) were 58.600 (5.0959), while for Salginate (medium body) they were 51.800 (0.8465) and 49.433 (1.0367) were the values of Panasil (light body). On the other hand, values obtained from the analysis of dimensional accuracy results showed no significant difference (p= 0.01) in the casts obtained, it has been concluded that although different types of PVS impression materials have been used, no difference in dimensional accuracy has resulted. However, the results suggested that the Panasil (light body) impression material showed less hardness. Furthermore, it has been found that accurate casts can be obtained by using different types of impression trays. The rigidity of different types of trays has not made a significant difference in the accuracy of implant impressions obtained.