Clinical evaluation of Procera AllCeram crowns in Japanese patients: results after 5 years.

Procera AllCeram crowns were prospectively evaluated clinically in both anterior and posterior regions in Japanese. One-hundred and one crowns were fabricated for 57 patients at the Tsurumi University Dental Hospital from August 2001 to October 2002 and evaluated according to the California Dental Association (CDA) quality evaluation system at baseline and annually at all follow-up examinations for 5 years. The plaque index (PI) and gingival index (GI) were recorded, and chipping and fracture were checked at the same time as well. A total of 75 Procera AllCeram crowns were evaluated, and the cumulative survival rate was 90.2% over the 5-year clinical trial. Six crowns experienced fractures within the veneering porcelain and from aluminium oxide coping, all of which occurred on the premolar and molar regions, and they had to be removed. Small chipping was observed on three crowns. According to the CDA criteria, 98% of Procera AllCeram crowns were rated as satisfactory, and PI and GI were comparable to those of control teeth during the observation period.