Mechanical and histomorphometric evaluations of rough titanium implants treated with hydrofluoric acid/nitric acid solution in rabbit tibia.

ABSTRACT

PURPOSE: The aim of this study was to investigate the bone response to rough titanium implants treated with hydrofluoric acid/nitric acid (HF/HNO3) solution. MATERIALS AND METHODS: Implants were treated with HF/HNO3 solution (test implants) or without HF/HNO3 solution (control implants). Forty-five test and 45 control implants were inserted into both tibias of 15 rabbits. After 2, 4, and 8 weeks in situ, tibias were retrieved and prepared for removal torque testing and histomorphometric evaluation. The removed implants were prepared and observed with an electron microscope. RESULTS: Mechanical tests showed that mean removal torque values for the test implants were higher than those of the control implants after 8 weeks (33.1 Ncm versus 25.7 Ncm, P = .012). Histomorphometric analysis showed that the bone area in the threads of the cortical bone region was significantly higher for test implants (81.99% and 86.38%) than for control implants (75.33% and 81.62%) after 4 and 8 weeks of healing, respectively. The implant-bone contact rate in the cortical region was higher for test implants than for control implants after 8 weeks in situ (79.56% versus 68.45%, P = .003). CONCLUSIONS: The treatment with HF/HNO3 solution promotes bone formation and osseointegration after 4 and 8 weeks of bone healing in the rabbit tibia model.