Effects of anodized implants coated with escherichia coli-derived recombinant human bone morphogenetic protein-2 on osseointegration in rabbits

The aim of the present study was to evaluate the effects of anodized implants coated with Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) on osseointegration using stability tests and histometric analysis. Nine adult New Zealand white rabbits (4.5-5 kg) were used in the study. Thirty-six implants (L, 5.0 mm; D, 4.0 mm) were divided into 2 groups: anodized implants (control group) and ErhBMP-2(1.5 mg/ml concentration, 18 μg: Cowellmedi Co, Busan, Korea) coated anodized implant (experimental group). In each rabbit, 4 implants were placed in the tibia on both sides. The control and experimental implants were randomly placed in either left or right tibia. The rabbits were sacrificed at the end of the healing period (2, 4 and 12 weeks after operation). The stability of implants was evaluated by resonance frequency analysis. To obtain histometric results, bone to implant contact (BIC) and intra-thread bone density (ITBD) were measured with a light microscope. The ISQ value was significantly greater in the experimental group than in the control group at 12 weeks (P<0.05). ITBD increased over time in the experimental group (P<0.05). Post hoc comparison test analysis showed that a statistically significant change could be found between 2 and 4 weeks in the interaction between the ITBD change by time lapse and an ErhBMP-2 application condition (P=0.033). In this study, a greater degree of ossointegration was observed in the experimental group. ErhBMP-2 coated anodized implants could be used particularly in cases where bone quality is poor or bone volume is insufficient.