Purpose: This longitudinal clinical trial studied the clinical performance of chairside CAD/CAM fabricated lithium disilicate crowns (IPS e.max CAD; Ivoclar) over ten years of service. Materials and Methods: 100 CAD/CAM lithium disilicate crowns were fabricated using the CEREC 3 system (Dentsply Sirona). The crowns were adhesively bonded in consecutive groups with one of three cements. ML = self-etching bonding agent and resin cement (MultiLink-Automix; Ivoclar), EC = self-adhesive resin cement (Experimental Cement; Ivoclar), and SC =self-adhesive, light-cured resin cement (SpeedCem; Ivoclar). Results: Mild sensitivity was reported on 15% of the teeth at 1 week. All sensitivity resolved by 4 weeks. At 6 months, 2 (8.7%) of the crowns cemented with ML and 3 (7.7%) of the crowns cemented with EC were described as slightly sensitive by the patient. No patient required treatment for sensitivity and there was no reported sensitivity at any subsequent recalls. The percent alpha scores were above 95% for color match and margin adaptation at all recall intervals. Four crowns debonded, 3 cemented with EC (13, 20 and 36 months) and 1 with ML (36 months). A second MultiLink crown debonded at 110 months (9 years, 2 months). There were four reported cases of crown fracture between 6 years 3 months and 9 years 9 months. There were two biological failures; one due to endodontic treatment and one due to fracture and loss of the core. Conclusions: The lithium disilicate crowns performed very well over 10 years. This study was supported by a grant from Ivoclar.
