Accuracy of two implant impression techniques: direct-splinted and direct-elastomeric

Objectives: The purpose of this in vitro is to compare the accuracy of two impression techniques: a direct technique with impression coping splinted with a metal splint and gypsum and another with elastomeric impression material and open tray. Materials and Methods: A stainless steel master model with six implant replicas in arch was used to make 5 impressions with a steel splint which fixed six implant replicas with impression plaster. An open tray and polyethers were used to make the other 5 direct pick-up impressions. Implant analogs were setting and impressions poured. A measuring scanner (0.001mm accuracy) was used to measure tri-dimensional (MOD XYZ) cast inter-implant distances and vertical (Z) discrepancies. Results: Repeated measurements indicated significant differences (p> .05) for the distance XY with steel splinted and gypsum compared to master model. Direct open tray and polyethers didnxt indicate significant differences (p> .05) compared to master model. Similar results were found for the vertical discrepancy Z. Conclusion: Splinted impressions with a metal splint and gypsum showed significant discrepancies for horizontal XY and vertical Z distances compared to a steel master model with 6 implant replicas. These significant discrepancies were not found in open tray direct impressions with polyethers.