Two years of clinical experience with Procera titanium crowns

The purpose of the study were to evaluate the clinical performance of the Procera porcelain-fused-to-titanium crown system in general practice during a 2-year period, and to evaluate the performance of a new low-fusing porcelain as a veneering material on titanium.

A number of consecutive complete-coverage crowns (40) in 25 patients (14 women and 11 men) with a mean age of 53.1 years (range 35 to 79 years) were made according to the Procera (Nobel Biocare) technique in a 3-month period. The titanium copings were fabricated from solid rods of pure titanium using spark erosion and copy-milling technique, whereafter they were veneered with a new type of low-fusing ceramic material. The crowns were evaluated using the CDA criteria at baseline and after 2 years.

The general failure rate was low and was restricted to one carious lesion, one porcelain fracture, and one loss of a crown resulting from failure of retention of a post and core. The most frequent single reason that the "excellent" color level was not recorded was a "too-high value." A slightly dull or granular porcelain surface was observed both at baseline and after 2 years. Overall, the responses of the patients were positive.

Within the limitations of the study it can be concluded that porcelain-veneered Procera titanium crowns can be used as an alternative to other porcelain-fused-to-metal systems. However, conclusions should be made with caution from the results of this study because of the limited number of patients and crowns and the short observation period.