IADR Abstract Archives
Accuracy of Different Digital Impression Systems.
Objectives: The purpose of this study was to test: the accuracy of digital impressions, master models obtained from different digital and conventional impression systems, and the accuracy of marginal and internal adaptations 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 (n=5) using different digital and conventional impression systems (CEREC, E4D, Lava C.O.S, 3Shape, iTero, and polyether) were made. Master models of these impressions were obtained according to the manufacturer recommendations. The accuracy of the impressions and the master models were evaluated by comparing them to the reference model using computer software. Final restorations were fabricated on the produced models and tested for marginal and internal adaptation using cement replica technique.
Results: Accuracy of the digital impressions (µm) were as follow: 3Shape 44(18), CEREC 68(12), Lava 36(19), E4D 84(4), and iTero 23(3), one way ANOVA test was significant (P≤0.001). 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). Internal adaptations by weight ((µg) were as follow: 3Shape 792(92), CEREC 704(18), Lava 563(37), iTero 638(26), E4D 772(78), and Stone 650(42), 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 digital impression systems, between the accuracies of the master models of each system, and between the marginal and the internal accuracies of the tested systems. The marginal gaps presented by all the tested systems were within the acceptable clinical limits.
Methods: An epoxy model of a three unit bridge was designed to be used as reference model. Dental impressions (n=5) using different digital and conventional impression systems (CEREC, E4D, Lava C.O.S, 3Shape, iTero, and polyether) were made. Master models of these impressions were obtained according to the manufacturer recommendations. The accuracy of the impressions and the master models were evaluated by comparing them to the reference model using computer software. Final restorations were fabricated on the produced models and tested for marginal and internal adaptation using cement replica technique.
Results: Accuracy of the digital impressions (µm) were as follow: 3Shape 44(18), CEREC 68(12), Lava 36(19), E4D 84(4), and iTero 23(3), one way ANOVA test was significant (P≤0.001). 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). Internal adaptations by weight ((µg) were as follow: 3Shape 792(92), CEREC 704(18), Lava 563(37), iTero 638(26), E4D 772(78), and Stone 650(42), 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 digital impression systems, between the accuracies of the master models of each system, and between the marginal and the internal accuracies of the tested systems. The marginal gaps presented by all the tested systems were within the acceptable clinical limits.