Comparison of the dimensional accuracy of splinted and unsplinted impression techniques for multi-unit abutment-an invitro study

Aims: The purpose of this study was to compare the dimensional accuracy of splinted and unsplinted impression techniques for the multiunit abutment. Methods and Material: A 3D transparent acrylic model with 4 implants (2 straight and 2 angulated) and 4 multiunit abutments was fabricated. A total of 26 polyether (aquasil ultra monophase) impressions of this model were made with pick-up type multiunit impression copings. Out of this, 13 impressions were made by splinting the copings and the remaining 13 impressions were made without splinting. The horizontal distance between the abutments on the casts obtained by both techniques was measured using a digital vernier caliper. These measurements were then compared with the master model measurements. Results: The dimensional accuracy of splinted impression technique was almost similar to that of the 3D die whereas the dimensional accuracy of the non-splinted impression technique was less when compared to that of the 3D die. This difference in the dimensional accuracy of splinted and non-splinted impression techniques was found to be statistically significant. Conclusions: The study concluded that the splinted technique produced more accurate master casts than the non-splinted technique for multiunit abutments.