Evaluation of the effect of different materials and techniques on implant impression accuracy by cone beam computed tomography

Aim: The aim of this study is to evaluate the effect of different materials and techniques on the measurement accuracy by comparing the distance and angle parameters of the impressions. Material and Method: Impressions were taken using polyvinyl siloxane (PVS) and polyvinyl siloxane ether (PVSE) impression materials using open tray (AK) and closed tray (KK) techniques on an acrylic mandible model with 4 implants placed parallel to each other. Impressions were scanned with cone-beam computed tomography and displayed with OnDemand3D program and measurements were made. Linear distances between analogs and posts and angulations of analog-post complexes relative to each other were measured. The obtained data were compared with the reference model image. Mann-Whitney U test was used for pairwise comparisons of non-normally distributed variables, and Kruskal-Wallis-H test was used for multi-group comparisons. Results: There was no significant difference between the groups in linear distance measurements between analogs and posts. In angular deviation values, AK-PVS group showed a significant difference compared to KK-PVS and KK-PVSE values (p<0.05). The lowest angular deviation was observed in the AK-PVS group (0.195° ± 0.145°), while the highest angular deviation was observed in the KK-PVSE (0.407° ± 0.507°). There was no correlation between the distance between the implants and the measurement accuracy. vii Conclusions: The open tray PVS showed better results than the closed tray PVS and, close tray PVSE. While the open tray impression technique showed similar results for both impression materials, the PVS impression material gave more accurate impressions in the impressions using closed trays.