Three-year clinical success and survival of composite based indirect restorations

Objectives: The objective of this study was to test the new resin composite “NECO” as a material for indirect restorations clinically. Methods: Forty-five patients were selected, of which 12 men and 33 women, with a mean age of 53. A total of 91 post-canine NECO (Heraeus Kulzer, GmbH) restorations were placed, of which 86 full crowns and 5 onlays. Restorations were cemented with either 2bond2 or Fuji Plus. The restorations were evaluated 1-2 weeks (baseline), 6 months, 1, 2, and 3 years after placement. At these recalls, success and survival data of the abutment teeth and of a comparable reference teeth which served as a control, were documented. Survival was defined as the restoration being in situ, and success as the restoration in situ without complications. Results: After 3 years of clinical service, the restorations had success and survival rates of 84.8 and 91.6%, respectively. Restorations were unsuccessful because of debonding (n=5) with possibility for recementation, endodontic (re)treatment need (n=5), and repairable core fracture (n=3). These restorations were continued to be followed after repair. Restorations did not survive because of irreparable core fracture (n=4), debonding (n=1), crown fracture (n=1), and root fracture (n=1). Cementation with Fuji Plus cement resulted in higher success (93.1%) and survival (100%) rates than cementation with 2bond2 cement of 81.4 and 87.9% respectively. Restorations on vital teeth resulted in higher success (86.8%) and survival (95.3%) rates than restorations on endodontically treated teeth of 82.6 and 87.5% respectively. Complications with vital teeth were mostly less severe than complications with endodontically treated teeth. Conclusion: Success and survival rates after three years of NECO restorations are 84.8 and 91.6%, respectively. Abutment teeth being vital and cementation with Fuji Plus leads to higher success and survival rates.