IADR Abstract Archives
Coating of titanium surfaces with hydroxyapatite and strontium on osseointegration
Objectives: The aim of this study was to develop surface treatments with hydroxyapatite and hydroxyapatite modified by strontium in two concentrations (10 and 90%) on titanium alloy surfaces (Ti-6Al-4V), to evaluate the chemical and morphological properties of these surfaces, as well as evaluate its osseointegration in healthy(control) and osteoporotic(OVX) female rats.
Methods: Fixing screws and titanium alloy discs were used, which divided into 4 groups: machined, Hap, HapSr10% and HapSr90%. The surface treatments with apatite were carried out by biomimetic method, from deposition of phospholipid bilayers in subphases containing CaCl2 and SrCl2, using the Langmuir-Blodgett technique and immersion in the SBF solution. The morphology characteristics, structure, chemical composition, wettability, surface energy and surface integrity were evaluated. They were tested in vivo, in which screws were randomized and installed in control and OVX tibias. Osseointegration was evaluated by biomechanical analysis (reverse torque), confocal microscopy, contact area between bone tissue and screw and linear extension 60 days after installation (BIC).
Results: In the laboratory analyzes, Hap, HapSr10% and HapSr90% were seen on rough, thin films and the presence of pores on a nanometric scale, the presence of Hap chemical groups similar to that of bone tissue, and a increase in wettability and surface energy. In the in vivo analyzes of reverse torque, in ovarectomized rats the values presented higher for surfaces coated by strontium, while in the control group the Hap surface showed greater torque for removing the screw. The fluorochrome area for calcein and the newly formed bone area were significantly greater on the HapSr10% compared to the control group. Regardless of the animals' systemic condition, the machined surface group showed lower values than the other groups
Conclusions: In conclusion, surfaces treated with HAp improve surface morphology, composition, and reactivity, and showed promoting effect on screw osseointegration in healthy and osteoporotic female rats.
Methods: Fixing screws and titanium alloy discs were used, which divided into 4 groups: machined, Hap, HapSr10% and HapSr90%. The surface treatments with apatite were carried out by biomimetic method, from deposition of phospholipid bilayers in subphases containing CaCl2 and SrCl2, using the Langmuir-Blodgett technique and immersion in the SBF solution. The morphology characteristics, structure, chemical composition, wettability, surface energy and surface integrity were evaluated. They were tested in vivo, in which screws were randomized and installed in control and OVX tibias. Osseointegration was evaluated by biomechanical analysis (reverse torque), confocal microscopy, contact area between bone tissue and screw and linear extension 60 days after installation (BIC).
Results: In the laboratory analyzes, Hap, HapSr10% and HapSr90% were seen on rough, thin films and the presence of pores on a nanometric scale, the presence of Hap chemical groups similar to that of bone tissue, and a increase in wettability and surface energy. In the in vivo analyzes of reverse torque, in ovarectomized rats the values presented higher for surfaces coated by strontium, while in the control group the Hap surface showed greater torque for removing the screw. The fluorochrome area for calcein and the newly formed bone area were significantly greater on the HapSr10% compared to the control group. Regardless of the animals' systemic condition, the machined surface group showed lower values than the other groups
Conclusions: In conclusion, surfaces treated with HAp improve surface morphology, composition, and reactivity, and showed promoting effect on screw osseointegration in healthy and osteoporotic female rats.