Comparison of Osseointegration Between Laser-Etched and Magnesium-Incorporated Oxidized Implants in the Rabbit Femur

Purpose: To compare the osseointegration of a laser-etched (LE) implant with a magnesium-incorporated oxidized (MgO) implant, evaluating their ability to enhance the bond strength between a titanium substrate and rabbit femur. Materials and Methods: Two type of dental implants, LE (test, commercially pure [CP] titanium grade 4) and MgO (control, CP titanium grade 4) (length, 8 mm; diameter, 3.3 mm), were evaluated for the surface characteristics using a field emission scanning electron microscope (FE-SEM), an energy dispersive spectrometer (EDS), and an optical three-dimensional profiling system. After that, two types of dental implants were implanted at the right and left distal femoral metaphysis of 10 adult rabbits weighing approximately 3.0 kg. After 6 weeks, histomorphometric analysis, removal torque tests, and surface analysis of the torque-tested implants were performed. Results: After surgery, the LE group showed thick bonelike materials within the pores observed using FE-SEM (magnifications ×500 and ×900). The mean removal torque was 40.72 ± 13.3 Ncm for the test (LE) implant and 22.26 ± 6.4 Ncm for the control (MgO) implant, respectively (P = .041). The mean bone-implant contact in the three best consecutive threads in the cortical region was 63.35% ± 16.44% in the LE group and 51.63% ± 5.09% in the MgO. Conclusions: In the beginning stage of cancellous bone healing, biomechanical properties of the LE implant could influence a more favorable bone response than that of MgO.