Effect of bisphosphonates on anodized and heat-treated titanium surfaces: an animal experimental study.

BACKGROUND

Recent investigations reported that osseointegration of titanium implants can be significantly reinforced with a nanostructure treated with anodic oxidation and heat treatment. This experimental study investigates the effect of bisphosphonates on the nanotubular implant surface in rats.

METHODS

Thirty-six titanium implants were divided into three groups: 1) machine-turned (MT), 2) anodized and heat-treated (AH), and 3) anodized and heat- and bisphosphonate-treated (AHB) groups. The 36 implants were randomly placed in both tibias of 18 male Wistar rats. After 2 and 4 weeks, the levels of osseointegration of the implants were evaluated by a removal torque test and microcomputerized tomography (μCT). Peri-implant bone tissue on the extracted region was examined for the expression of type I collagen and osteocalcin.

RESULTS

The AHB group showed the highest removal torque at 2 and 4 weeks (13.92 ± 1.51 Ncm and 18.10 ± 2.15 Ncm, respectively) followed, in order, by the AH group (11.63 ± 1.58 Ncm at 2 weeks and 14.80 ± 2.34 Ncm at 4 weeks) and MT group (4.30 ± 0.76 Ncm at 2 weeks and 6.20 ± 1.33 Ncm at 4 weeks) with statistically significant differences between the MT and other two groups at both time points. μCT images also revealed a denser appearance around implants in the AHB group than in the other groups. Levels of type I collagen and osteocalcin expression were similar between the MT and AH groups; however, the values were significantly higher in the AHB group compared to the other groups, which were 220.85% ± 71.09% and 363.04% ± 100.21%, respectively (P <0.05).

CONCLUSION

Within the limits of this experiment, it was concluded that surface loading with bisphosphonates significantly improved the degree of osseointegration of titanium implants with a nanostructure.