Effect of Bisphosphonates on Anodized and Heat-Treated Titanium Surfaces: An Animal Experimental Study: An animal experimental study

Background: Recent investigations reported that osseointegration of titaniumimplants 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 heattreated (AH), and 3) anodized and heat- and bisphosphonatetreated (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 theAHBgroup 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.