Accuracy of CAD/CAM Crowns Produced by two Different Scanners

Objectives: The fitting accuracy of dental restorations manufactured in a fully digitized workflow depends mainly on the type of scanner used. The present investigation aims to examine the accuracy and fit of digitally fabricated lithium disilicate single crowns produced by two different scanners.
Methods: Twenty non-carious molar teeth were ideally prepared for a lithium disilicate crown. The prepared teeth were digitally scanned twice using two intraoral scanners (Planmeca & iTero). Subsequently, the 3D design of lithium disilicate crowns was generated using Romexis, and these digital designs of the crowns were milled using the Planmeca milling machine. For each tooth, the marginal fit for both crowns was recorded using a digital microscope (VR-3100; Keyence) at three preselected locations (mesial buccal, straight buccal, and distal buccal) at 40x magnification. The gap width was evaluated and recorded as the vertical distance between the tooth structure and restoration interface at a constant predetermined location per tooth.
Results: There was a consistency between the three readings taken for iTero’s samples, while the Planmeca samples showed discrepancies between the three readings. The overall average of marginal fit measurements of iTero’s crowns was lower when compared to Planmeca’s crowns. No statistically significant difference between the two groups was recorded (P=0.067). The marginal discrepancy for all constructed crowns was within the accepted clinical range.
Conclusions: Within the limitation of the presence research, it was concluded that the Planmeca and iTero intraoral scanners manufactured crowns with no significant differences in their marginal fit.