Micro-computed tomography evaluation of marginal fit of lithium disilicate crowns fabricated by using chairside CAD/CAM systems or the heat-pressing technique

The marginal fit of E.max Press and E.max CAD lithium disilicate restorations: A critical review

“…The mean marginal gap was 39.2±8.7 SD microns for group 1, 66.9±31.9 SD microns for group 2, and 36.8±13.9 SD microns for group 3. E.max Lithium disilicate crowns fabricated with either the -Cerec 3D Bluecam scanner CAD/CAM or heat-press techniqueachieved significantly smaller marginal gaps than crowns fabricated with the -CAD/CAM E4D Laser scanner-(p-value 0.046) 38) . These results compare favourably with the CAD E4D results of Mously and colleagues.…”

“…Neves and colleagues 38) compared the marginal fit of E.max press and E.max CAD crowns. Three groups were assessed: Group 1 (E.max CAD CEREC 3D bluecam scanner), group 2 (E.max CAD E4D laser scanner), group 3 (E.max Press).…”

“…Neves and colleagues 38) showed a significantly smaller marginal gap of E.max Lithium disilicate crowns fabricated with (Cerec 3D Bluecam scanner CAD/CAM system) or the heat-press technique than E.max Lithium disilicate crowns fabricated with (CAD/ CAM E4D Laser scanner) 38) . However, the sample size of this study was very small (5 specimens per group) compared to other studies like Guess and colleagues (24 specimens per group), which could be inadequate to give a significant result.…”

“…The search identified 13 studies that met the inclusion criteria. Out of the 5 studies that compared the marginal fit of E.max press and E.max CAD restorations, the majority (n=3) found that the E.max lithium disilicate restorations fabricated with the press technique had significantly smaller marginal gaps than those fabricated with CAD technique 10,37,38) . This finding may be related to the scanning device accuracy, software design, spacer settings, and milling machine accuracy [41][42][43] .…”

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“…This fact is especially important when using the CAD/ CAM technology, in order to provide precise mock-up scanning, allowing adequate design and milling of the ceramic restorations. Furthermore, the chairside CAD/CAM system eliminates some laboratory steps, saving clinical time with excellent fit, besides meeting the esthetic demands of patients [10,11]. The choice of which technique and veneering material to use depends on the position, shape, number of teeth involved and degree of enamel discoloration, besides the physical properties of the restorative materials and their bond capability, and no less important, the expertise of the operator.…”