Impact Fracture Resistance of Two Titanium-Abutment Systems Versus a Single-Piece Ceramic Implant

The number of patients with oral implants has increased significantly. However, the literature addressing the effect of impact force on titanium and/or ceramic implants is inconclusive. This study sought to determine the fracture resistance to impact load of titanium and ceramic endosseous oral implants. Materials and Methods: Endosseous oral implants were vertically positioned in two different mounting media: brass and a bone-simulation material. The implant configurations tested included an experimental one-piece Y-TZP implant and a commercially available titanium implant (external hex) with both titanium and zirconia abutments. The specimens were subjected to an impact load using a pendulum impact tester with tup weights varying from 0.9 to 4.5kg delivered at a radius of 40.64mm. Loads were delivered to the abutment at a point 4.27mm above the implant fixture and block junction. Statistical differences (p<05) were established using the F-test for variances and, when different, t-test assuming unequal variances. Results: For implants clamped in brass, the titanium implant with titanium abutment required the greatest energy to fracture the implant-abutment system (only the abutment screw failed). The ceramic implant and ceramic abutment on titanium implant presented the lowest fracture energy (p<01). No significant differences were observed when different systems were inserted into the foam blocks of the bone substitute (p>25). Conclusion: This investigation showed that the fracture energy of two titanium-abutment systems versus a single-piece Y-TZP implant in foam blocks simulating bone elastic modulus was not different, and that differences occurred when the embedding material elastic modulus was increased an order of magnitude.