Fracture force of cantilevered zirconia frameworks: An in vitro study Kenny K. H. Chong, BDS, DClinDent,a Joseph Palamara, Dip Ed, PhD,b Rebecca H. K. Wong, BDSc, MDSc, PhD,c and Roy B. Judge, BDS, RCS, MDSc, PhDd Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Australia Statement of problem. Little evidence is available showing the effect of connector dimension and cantilever length on the ultimate fracture force of computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia implant frameworks. Purpose. The purpose of the study was to determine the impact of variations in the cross-sectional dimension of connector sites and variations in the effective cantilever length (load point) on zirconia implant frameworks. This would allow verification of the fracture force with 2 proposed mathematical models. Material and methods. Forty zirconia implant-supported frameworks with 12 mm distal cantilevers were divided into 4 equal test groups (n¼10). Connector dimensions (35 mm, 34 mm) and cantilever loading distance (7 mm, 10 mm) were tested for ultimate fracture force. A 2-way analysis of variance (ANOVA) was used to examine the ultimate fracture force and examine the relationship between connector dimension and ultimate fracture force. The data obtained from all 4 groups were compared and verified with calculations from 2 theoretical mathematical models. Results. Two-way ANOVA revealed significant effects for cross-sectional area connector dimension on fracture force (P