Longevity of Repaired Composite and Metal-Ceramic Restorations: 3.5-Year Clinical Study

Objective: The aim of this clinical study was to document the outcomes of repaired ceramic-fused-to-metal (CFM) and resin-composite (RC) restorations in patients treated at the Dental School in Groningen up to 3.5 years. Methods: Between June-2002 and January-2006, 20 patients (12 females, 8 males, 20-82 years), with 41 failed CFM due to chipping or fracture and 59 patients (27 females, 32 males, 15-86 years), with 146 failed RC restorations due to fracture, chipping, discoloration, form and colour corrections leading to a total number of 187 restorations (74 and 36 anterior, and 72 and 5 posterior for RC and CFM, respectively) were repaired. After bevel preparations, repair was accomplished using HF (9.6%, 90s) (Ultradent) and/or silica-coating+silanization for CFM and only silica-coating+silanization for RCs (Özcan M. J Prosthet Dent 2002) as conditioning methods and Quadrant Anterior Shine (Cavex) and Sinfony (3M ESPE) as repair composites. Following polymerization, occlusal adjustments were made and the restoration was finished and polished. Patients were instructed to call upon experience of a failure. The annual standard protocol involved operator defined criteria for evaluation of technical failures like chipping or fracture (tooth/restoration), ditching and discoloration at the margins. Results: 57% of the RC repairs were due to form and colour corrections associated with fiber-reinforced restorations. In CFM repairs, 55% of the failures were at the opaque/ceramic interface and 27% with metal exposure. While only one fracture was observed for CFMs 1 week following the repair, 2 occasions of chipping/fractures were observed for RCs within the 1st month. Four repaired RCs showed marginal discoloration after 1 year, and 2 after 2 years. Life-tables calculated from the data and Kaplan-Meier curves revealed a survival of 97.6% for CFM and 98.3% for RCs. Conclusions: Repair methodologies and materials employed in this study resulted in satisfactory longevity for both CFM and RCs.