Affiliation:
1. Department of Reconstructive Dentistry, Dental School, Faculty of Medicine and Health Sciences Ghent University Ghent Belgium
2. Department of Periodontology, Dental School, Faculty of Medicine and Health Sciences Ghent University Ghent Belgium
Abstract
AbstractAimIn this pilot study, the fracture resistance of hybrid abutments with different restoration lengths was investigated.Materials and MethodsSixteen monolithic zirconia restorations of an upper right incisor were designed to fit a titanium base abutment. Eight central incisors had a crown length of 8 mm (T1) and the other half a length of 12 mm (T2). All crowns were cemented on the titanium base using a resin cement. After cementation, the samples were placed in a thermocycler for 5000 cycles. Fracture strength was measured using a universal test machine. Deformations and fractures of the samples were investigated.ResultsThe mean fracture resistance of T1 was 515 N (SD 96 N, 339–650) and 305 N (SD 57 N, 234–408) for T2 (p < 0.001). Both groups showed deformation of the titanium base, with no significant difference between both groups (p = 0.200). A difference in fracture type (p = 0.013) was observed, with significantly more screw fractures occurring in group T1 (p = 0.026).ConclusionWithin the limitations of this study, hybrid restorations with standard titanium base abutments can withstand forces that have been associated with chewing, irrespective of the crown length. However, the shorter crowns demonstrated more fatal fractures.