Survival rate of mono-ceramic and ceramic-core CAD/CAM-generated anterior crowns over 2-5 years

Anterior mono-ceramic (Mk II, n = 18) and ceramic core (In-Ceram Spinell, n = 18) crowns were CAD/CAM-fabricated using Vitablocs with the Cerec 2 CAD/CAM system and bonded in 24 patients. All crowns were rated using modified United States Public Health Services (USPHS) criteria at baseline and after a service time of 2-5 years. Survival of the crowns, regarding fracture, was analysed (Kaplan-Meier) after 44.7 +/- 10.3 months. Gingival health at crowns was assessed using plaque and bleeding scores. One core crown and one mono-ceramic crown had fractured after 42.5 months and 12 months, respectively, with survival rates of 91.7% for In-Ceram Spinell and 94.4% for Mk II; the difference was not statistically significant. Between baseline and follow-up examinations, non-significant shifts from A- to B-ratings occurred, particularly for marginal adaptation, for both crown types. Plaque and bleeding scores did not differ between the ceramic crown types but showed significantly less plaque and less bleeding at ceramic crowns than at control teeth at follow-up. The clinical performance of mono-ceramic crowns was judged to be similar to that of ceramic core crowns.