ABSTRACT
BACKGROUND: Irradiation therapy in the cancer patients after surgery may have negative effects on implant fixation. OBJECTIVE: To observe the effects of 60Co irradiation and trace element zinc on fixation strengths of titanium implant. METHODS: Thirty-six adult male rabbits were involved. One piece of titanium implant was separately placed into the bilateral proximal tibial heads in rabbits to set up animal models of titanium implants. The animals were randomly divided into control group, zinc supplement group, 60Co irradiation group and 60Co irradiation and zinc supplement group. Zinc sulfate of 10 g/L was administered intramuscularly to animals in the zinc supplement group at the dose of 4 mg/kg once per day, and those in the control group were treated with saline at the same dose. The animals in the 60Co irradiation group received 60Co irradiation at the dose of 45 Gy and saline by intramuscular injection. Those in the 60Co irradiation and zinc supplement group received 60Co irradiation and zinc sulfate. The animals were killed at 1, 4 and 12 weeks after treatment. The fixation strengths were measured and compared among groups. RESULTS AND CONCLUSION: (1) Zinc supplement made the titanium implants have higher fixation strengths, and reach a high level at 4 weeks after surgery. (2) 60Co irradiation significantly inhibited the fixation strengths of the implants. After 60Co radiation, zinc supplement stil could promote fixation strengths of titanium implants. (3) It is indicated that amount of zinc supplement after irradiation therapy can al eviate the negative effects of irradiation on implant fixation.