Comparison of the Accuracy of Digital Impressions and Master Models

Objectives: To compare the accuracy of the digital impressions obtained from Cadent™ iTero and Lava™ C.O.S. Also the accuracy of master models obtained from Cadent™ iTero, Lava™ C.O.S., and stone master models from using conventional impressions technique.
Methods: A reference model was scanned to generate a CAD reference model (CRM). 10 digital impressions were taken using iTero, and another 10 digital impressions using Lava™ C.O.S. The scans were sent for fabrication of master models. The digital impressions were compared to the CRM using Qualify software. 10 conventional impressions of the reference model were taken then poured with Die stone (Resin Rock). All the master models were scanned and then compared to the CRM using the same software. The root mean square (RMS) values were analyzed. Independent-samples t-tests with Bonferroni correction were used in the first part of the study, and one-way ANOVA tests with Bonferroni correction were used in the second part of the study (α ≤ 0.017).
Results: The results of the first part of the study revealed that the digital mpressions obtained from the Lava ™ C.O.S. were more accurate compared to iTero (p-value <0.001). The results of the second part of the study demonstrated significant differences between groups (p-value <0.001). Master models obtained from using conventional impression technique were the most accurate, followed by master models obtained from Lava™ C.O.S. and lastly the master models obtained from iTero. There was no statistically significance between Lava™ C.O.S. and iTero in the full coverage design).
Conclusions: Within the limitations of this study we concluded that digital impressions obtained from using Lava™ C.O.S. are more accurate compared to digital impressions obtained from using Cadent™ iTero. Master models obtained from using conventional impression technique are more accurate than master models obtained from Lava™ C.O.S. and the Cadent™ iTero.