Load-bearing capacity and wear characteristics of short fiber-reinforced composite and glass ceramic fixed partial dentures

The aim of this study was to evaluate load-bearing capacity and wear performance of experimental short fiber-reinforced composite (SFRC) and conventional lithium-disilicate CAD/CAM fabricated fixed partial dentures (FPDs). Two groups (n = 12/group) of three-unit CAD/CAM fabricated posterior FPDs were made. The first group used experimental SFRC blocks, and the second group fabricated from lithium-disilicate (IPS e.max CAD). All FPDs were luted on a zirconia testing jig with dual-curing resin cement. Half of FPDs per group were quasi-statically loaded until fracture. The other half experienced cyclic fatigue aging (100.000 cycles, Fmax = 500 N) before loading quasi-statically until fracture. Fracture mode was examined using SEM. Wear test was performed using 15,000 loading cycles. Both material type and aging had a significant effect on the load-bearing capacity of FPDs. Experimental SFRC CAD without fatigue aging had significantly the highest load-bearing capacity (2096 ± 149N). Cyclic fatigue aging decreased the load-bearing capacity of the SFRC group (1709 ± 188N) but increased it for the lithium-disilicate group (1546 ± 155N). Wear depth values of SFRC CAD (29.3μm) were significantly lower compared to lithium-disilicate (54.2μm). Experimental SFRC CAD demonstrated the highest load-bearing capacity before and after cyclic fatigue aging, and superior wear behavior compared to the control material.