Indirect zirconia-reinforced lithium silicate ceramic CAD/CAM restorations: Preliminary clinical results after 12 months

Objective: No clinical data are available for the new computer-aided design/computer-assisted manufacture (CAD/CAM) material zirconia-reinforced lithium silicate (ZLS) ceramic. This study describes preliminary clinical results for indirect ZLS CAD/CAM restorations after 12 months. Method and Materials: Indirect restorations were fabricated, using the CEREC method and intraoral scanning (CEREC Omnicam, CEREC MCXL). Sixty-seven restorations were seated adhesively (baseline). Sixty restorations were evaluated after 12 months (follow-up), using modified FDI criteria. Two groups were established, according to ZLS restorations' post-processing procedure prior to adhesive seating: group I (three-step polishing, n = 32) and group II (fire glazing, n = 28). Statistical ana-lysis was performed with Mann-Whitney U test and Wilcoxon test (P <.05). Results: The success rate of indirect ZLS CAD/CAM restorations after 12 months was 96.7%. Two restorations clinically failed as a result of bulk fracture (failure rate 3.3%). No statistically significant differences were found for baseline and follow-up criteria (Wilcoxon test, P >.05). Statistically significant differences were found for criteria surface gloss for group I and group II (Mann-Whitney U test, P <.05). Conclusion: This study demonstrates ZLS CAD/CAM restorations have a high clinical success rate after 12 months. A longer clinical evaluation period is necessary to draw further conclusions.