[Preliminary clinical results of a prospective study of IPS e.max Press- and Cerec ProCAD- partial coverage crowns]

It was the aim of this prospective clinical splitmouth investigation to evaluate the survival rate and long-term behavior of all-ceramic partial coverage restorations (PCR) on molars. Pressed ceramic (IPS e.max Press) and CAD/CAM made (ProCAD) PCR were compared. 80 vital molars of 25 patients were restored with all-ceramic PCR (40 IPS e.max Press* and 40 ProCAD*). All PCR were adhesively luted with a light-polymerizing composite (Syntac*/Tetric*) (*Ivoclar-Vivadent AG, Schaan, Liechtenstein). The ProCAD PCR were produced with Cerec 3 and Cerec Inlab CAD/CAM system (Sirona Dental Systems, Bensheim, Germany). IPS e.max Press PCR were heat-pressed following the lost-wax IPS-Empress method. Clinical recall was arranged in average 8, 14, 20 and 28 months after cementation of the restoration. PCR were classified by USPHS criteria. The prospective survival rate of ProCAD PCR was 97% and 100% for IPS e.max Press PCR after an observation period of 24 months. After fracture, one ProCAD restoration had to be replaced after nine months. The clinical accuracy of the marginal fit of ProCAD PCR and IPS e.max Press PCR was recorded "Alfa". Limitations were recognized with respect to the color matching of both types of PCR ("Bravo").

Within the limits of the present clinical results, the tested all-ceramic materials IPS e.max Press und ProCAD seem to be indicated for partial coverage restorations on molars.