Clinical performance of CAD/CAM-fabricated lithium-disilicate-based glass ceramic vs. multilayer zirconia crowns after a minimum observation period of two years

OBJECTIVES: To evaluate survival and success of ceramic crowns fabricated either of a lithium-disilicate-based glass ceramic or of a high translucent multilayer zirconia. METHODS: Patients who received a computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated lithium-disilicate-based glass ceramic (CEREC Tessera, Dentsply Sirona) or high translucent multilayer zirconia (Katana Zirconia STML, Kuraray Noritace Inc.) crown were examined after a minimum observation time of 24 months. Two calibrated examiners assessed clinical performance of crowns using World Dental Federation (FDI) criteria. Survival and success rates were calculated using Kaplan-Meier method and statistically compared by log-rank test and Cox regression analysis. FDI criteria were compared by Mann-Whitney U tests (α=.05). RESULTS: One-hundred restorations (n = 50 lithium-disilicate-based glass ceramic, n = 50 multilayer zirconia) placed in 63 participants were included. Multilayer zirconia crowns presented significantly (p < 0.01) higher survival (2-year-survival: 100%, mAFR: 0.0%) and success rates (2-year-success: 100%, mAFR: 0.0%) compared to restorations made from lithium-disilicate-based glass ceramic (2-year-survival: 82.0%, mAFR: 9.4%; 2-year-success: 82.0%, mAFR: 9.4%). Thirteen crowns made from lithium-disilicate-based glass ceramic (bulk fractures: n = 10, endodontic complication: n = 3) and 2 multilayer zirconia crowns failed (endodontic complication: n = 1, loose after loss of retention: n = 1). FDI criteria were not significantly different between both groups. SIGNIFICANCE: Material selection is a critical determinant of the clinical performance of ceramic crowns. Short-time survival of lithium-disilicate-based glass ceramic was significantly lower compared with a high translucent multilayer zirconia.