Effect of different doses of aspirin on the early osseointegration of titanium alloy implants in rats

To investigate the effects of different doses of aspirin on the early osteointegration of titanium alloy implants in the femurs of rats to provide a reference for dental implantation in patients who take aspirin.

Forty-eight 8-week-old SD male rats were randomly divided into four groups, namely, the control, A, B, and C groups. Forty-eight Ti-6Al-4 V implants with a diameter of 1.4 mm and a length of 6 mm were implanted at the distal end of the right femur. In the A, B, and C groups, dosages of aspirin of 8.93 mg/kg/d, 17.86 mg/kg/d, and 26.79 mg/kg/d were administered by gavage starting on the day of surgery, and the control group was given similar doses of 0.9% saline. HE, Masson, BMP-2 immunohistochemical and TRAP staining evaluations were performed in the 2nd and 4th weeks after surgery.

Compared with the results in the control group, the HE staining results showed that the amount of new bone formation was reduced, the trabeculae were more sparse, and the bone marrow cavity was enlarged around the implants in the B and C groups, with the C group showing the most obvious effects. The Masson staining results showed that, compared with that in the control group, the red-stained area in the new bone tissue around the implant was reduced in groups B and C, and the reduction in group C was more significant. However, there was no significant difference between group A and the control group. The BMP-2 staining results indicated that the expression of BMP-2 was not significantly different between the control group and the A group (P > 0.05), and the expression in group C was lower than that in the other groups (P < 0.05). The TRAP staining results demonstrated that the number of positive cells per unit area was decreased sequentially in the control, A, B, and C groups, and the difference was statistically significant (P < 0.05).

Aspirin may reduce the formation of bone tissue by inhibiting the activity of osteoblasts and expression in osteoclasts. This effect on osteogenesis was aspirin dose-dependent, and large doses of aspirin can inhibit osteogenesis more significantly.