Fracture strength of various titanium‐based, CAD‐CAM and PFM implant crowns

Objective CAD‐CAM has dramatically advanced dental restorative procedures to include implant‐supported crowns. The purpose of this study was to compare the fracture resistance following mechanical loading and thermocycling of various screw‐retained and cement‐retained ceramic and polymethylmethacrylate material combinations using the TiBase abutment compared to PFM implant‐supported crowns. Overview Twelve implant restorations were fabricated for each of eight groups. Three groups were screw‐retained and five groups were cement‐retained implant restorations. The ceramic and polymethylmethacrylate restorations were fabricated on the TiBase abutment while the PFM restorations were fabricated on an UCLA abutment. Data were analyzed with a one way Analysis of Variance and Tukey's post‐hoc test to evaluate the effect of abutment and crown type on fracture load (alpha = 0.05). A significant difference was found in the maximum fracture load between groups (P < 0.001). Conclusions The screw‐retained implant restorations demonstrated higher fracture loads than their cement‐retained counterparts. The TiBase abutment compared favorably to the UCLA abutment. Clinical Significance The TiBase abutment is a titanium insert which combines the esthetics of a ceramic abutment with the mechanical properties of a titanium abutment and should be considered a viable clinical alternative to the conventional implant‐supported PFM crown based on theses in vitro results and in context of in vivo studies. The lithium disilicate hybrid abutment/crown implant‐supported restoration utilizing the TiBase abutment may be an ideal clinical choice due to simplicity, single appointment CAD‐CAM, and esthetics.