Accuracy of Master Casts Achieved from Five Different Digital Impression Systems.

Objectives: The objectives of this study were to test: 1- the accuracy of master models obtained from different digital and conventional impression systems, and 2- the accuracy of the final restoration fabricated using these systems.
Methods: An epoxy model of a three unit bridge was designed to be used as reference model. Dental impressions using different digital and conventional impression systems were made. Master models of these impressions were obtained. The accuracy of the master models was evaluated by comparing them to the reference model using computer software. Final restorations were fabricated on the produced models and tested for marginal adaptation using replica technique.
Results: The accuracy of the master models (µm) were as follow: 3Shape 67(20), CEREC 116(5), Lava 48(9), E4D 117(12), iTero 64(27), and Stone 31(5), one way ANOVA test was significant (P≤0.001). The marginal gaps (µm) were as follow: 3Shape 70(8), CEREC 80(2), iTero 86(4), Lava 69(9), Stone 95(6), and E4D 106(14), one way ANOVA test was significant (P≤0.001).
Conclusions: There is a statistically significant difference: between the accuracies of the tested master models of each system, and between the marginal accuracies of the tested systems. The marginal gaps presented by all the tested systems were within the acceptable clinical limits.