Computer-Aided-Design/Computer-Assisted-Manufactured Adhesive Restoration of Molars with a Compromised Cusp: Effect of Fiber-Reinforced Immediate Dentin Sealing and Cusp Overlap on Fatigue Strength

作者：Magne Pascal^*; Boff Luis L; Oderich Elisa; Cardoso Antonio C

来源：Journal of Esthetic and Restorative Dentistry, 2012, 24(2): 135-146.

DOI：10.1111/j.1708-8240.2011.00433.x

Statement of Problem: Cracked teeth may traditionally require the use of complete coverage crowns. Alternative conservative treatments involve the use of adhesive inlays/onlays with the possibility of including a fiber patch to reinforce the cracked cusp. Purpose: The purpose of this study was to evaluate the fatigue strength of compromised molars restored with computer-aided-design/computer-assisted-manufactured (CAD/CAM) composite resin inlays/onlays with and without fiber-reinforced immediate dentin sealing (IDS). Methods and Materials: Large mesio-occluso-distal preparations with cracked/undermined palatal cusps were simulated on 40 extracted maxillary molars. All teeth received IDS (Optibond FL, Kerr, Orange, CA, USA), and composite resin (Paradigm MZ100, 3M-ESPE, St. Paul, MN, USA) inlays (N = 20) and onlays (N = 20). A fiber patch (Ribbond, Ribbond Inc., Seattle, WA, USA) was applied in half of the preparations. Restorations were adhesively luted with pre-heated composite resin (Z100, 3-M ESPE) and submitted to cyclic isometric loading at 5 Hz, starting with a load of 50 N (5,000 cycles), followed by stages of 150, 300, 450, 600, 750, 900, and 1,050 N at a maximum of 25,000 cycles each. Specimens were loaded until fracture or to a maximum of 180,000 cycles. Groups were compared using the life table survival analysis. Results: Differences in survival probability were found (p = 0.04). The inlay group with fiber patch failed at an average load of 870 N, and none of the specimens withstood all 180,000 load cycles; survival rates of inlays and onlays without fibers, and onlays with fibers were 10, 30, and 50%, respectively. Conclusions: Onlays (with or without fibers) increased the fatigue resistance of compromised molars in this in vitro study. CLINICAL SIGNIFICANCE The results of this in vitro study suggest that molars with a compromised cusp may be best reinforced by a cusp-protecting composite resin onlay. There was no benefit of using fiber reinforcement under those indirect restorations. (J Esthet Restor Dent 24:135147, 2012)

• 出版日期2012-4