In Vivo Evaluation of Titanium Implants Bioactivated by a Modified Kokubo’s Treatment

Abstract

In this study a modified Kokubo’s treatment (MKT) was used to bioactivate titanium implants. Titanium surfaces were alumina-blasted and etched in HCl/H2SO4 solution followed by treatment in autoclave at 120˚C for 1, 3, 5 hour periods with chemical solutions containing 1, 2 and 3 M of NaOH. The materials were characterized by surface angle measurements, roughness, field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and in vivo tests. Statistical analysis by polynomial regression showed that solutions within 2.2 and 2.8 M NaOH lead to surface contact angles close to zero degree after 1 h of treatment. XPS analysis carried out on a sample treated 1 h in 2.2 M NaOH indicated the presence of a titanate film. This solution was selected to treat titanium implants for in vivo tests. These tests were performed on sheep in three types of separating surfaces: machined group (standard), SLA group (A) and MKT group (B) divided into two time intervals of 3 and 6 weeks. The samples in group B displayed better results compared to group A only after 6 weeks in terms of counter torque and bone implant contact (BIC).