Method: 65 FDPs were inserted in 58 patients (mean age: 46.8 ± 12.7 years). 51 patients received one FDP while 7 patients received two FDPs. 12 FDPs replaced a second premolar and 53 FDPs replaced a first molar. The abutment teeth received a full-crown preparation with 1 mm circumferential and 1.5 mm occlusal reduction and a chamfer or shoulder finishing line. The In-Ceram zirconia frameworks were designed and milled using the Cerec 3 CAD/CAM system. The standard minimal framework thickness was 1.0 mm occlusally and 0.7 mm circumferentially, and the proximal connector dimensions (height x width in mm) were at least 4 x 3 or 4 x 4 for the premolar and molar, respectively. After milling, the frameworks were glass-infiltrated and veneered with a feldspathic ceramic. All FPDs were cemented with glass-ionomer cement. Clinical follow-up examinations were performed annually. Statistical analysis was performed using Kaplan-Meier survival analysis.
Result: The mean observation time was 109.6 months (SD = 27 months). The cumulative survival rate was 92% after an observation period of 10 years. Six patients were regarded as drop-outs, because they did not attend the recall program for more than 24 months. Five FDPs failed and had to be replaced due to biologic and technical complications. Framework fracture was reported for two FDPs (3.1%), one of them caused by a dentist during third molar extraction. Complications were reported as following: 31% chipping, 30% Biologic complications (caries, loss of vitality) and 6.5% loss of retention. Nevertheless, 55% of FDPs were free of any kind of complication.
Conclusion: Three-unit FDPs made of In-Ceam Zirconia seem to present a viable treatment alternative for all-ceramic posterior FDPs.