J Prosthodont. 2021 Aug 12. doi: 10.1111/jopr.13415. Online ahead of print.
ABSTRACT
PURPOSE: To evaluate the fracture resistance and fracture patterns of single implant-supported crowns with different prosthetic designs and materials.
MATERIALS AND METHODS: One hundred and forty-four identical crowns were fabricated from zirconia-reinforced lithium silicate (ZLS), leucite-based (LGC), and lithium disilicate (LDS) glass-ceramics, reinforced composite (RC), translucent zirconia (ZR), and ceramic-reinforced PEEK (P). These crowns were divided into 3 subgroups according to restoration design: cementable crowns on a prefabricated titanium abutment, cement-retained crown on a zirconia-titanium base abutment, and screw-cement crown (n = 8). After adhesive cementation, restorations were subjected to thermal-cycling and loaded until fracture. The fracture patterns were evaluated under a stereomicroscope. Statistical analysis was performed by using 2-way ANOVA/Bonferroni multiple comparison post hoc test (α = .05).
RESULTS: For each prosthetic design, ZR presented the highest fracture resistance (P≤.005). Other than the differences with ZLS and RC for screw-cement crowns (P>.05) and RC for crowns on zirconia-titanium base abutments (P>.05), LGC showed the lowest fracture resistance. P endured higher loads than LDS (P<.001), except for the crowns on zirconia-titanium base abutments (P>.05). Cementable crowns presented the highest fracture resistance (P<.001), other than LGC and LDS. The differences between LGC crowns (P>.05) or LDS crowns on prefabricated titanium and zirconia-titanium abutments were nonsignificant (P = .133). Fragmented crown fracture was predominant in most of the restorations. Screw and abutment fractures were observed in ZR screw-cement crowns, and all P crowns were separated from the abutments.
CONCLUSIONS: Restorative material and restoration design affect the fracture resistance and fracture pattern of implant-supported single-unit restorations. Clinicians may restore single-unit implants in premolar sites with the materials and prosthetic designs tested in the present study. This article is protected by copyright. All rights reserved.
PMID:34383979 | DOI:10.1111/jopr.13415
