Vol. 11, Issue 3, Part B (2025)

Objective: The purpose of the study is to evaluate and compare the effect of subgingival depth of the implant on the accuracy of the open tray implant impressions made using single step and 2 step technique with different impression materials. Material and Method: The study was performed on a maxillary edentulous heat cure acrylic resin master model with 4 implant analogs embedded parallelly in canine and 1st molar region, bilaterally, at different subgingival depths of 2mm,3mm,4mm and 5mm. A 30mm cylindrical rod was inserted in the center of palatal region of the master model to serve as a reference point from which the linear dimension of each impression coping was measured. Elastomers used to make open tray impression of the master model were medium body polyether and putty-light body addition silicone. Accordingly, the grouping was done. Group A- Single step impression technique using Medium Body Polyether impression material. Group B- Single step impression technique using Putty and Light Body Addition Silicone impression material. Group C-Two step impression technique using Putty and Light Body Addition Silicone impression material. Impressions were poured with Type IV Gypsum product (Die stone). The linear dimensional change was recorded by measuring distance of each impression coping from the central reference rod with Coordinate Measuring Machine (CMM). The data so obtained was compared and analyzed statistically. Results: The results revealed that Group C produced more accurate implant impressions for deeply placed implants. Besides, Group A and Group B have produced comparable results. Conclusion: It can be concluded that two step addition silicone impression technique may be used for producing accurate impressions of implants placed at deeper subgingival depth. Meanwhile, Polyether impressions and Single step addition silicone impression have shown comparable dimensional accuracy at all depths.