2.5.1. Fabrication of Implants

Forty implants (Ø 4.0 × H 8.0; Cowellmedi Co., Busan, Korea) were prepared for animal study. All of the the treated implants were fabricated by pure titanium (grade 4), and had microthreads on one end and broader threads on the other. Implant surfaces were anodized (Cowellmedi Co., Busan, Korea), and anodized implants were used as controls (Ti group), the experimental groups were as follows; the heparinized implant group (the Hepa/Ti group), the rhPDGF-BB (0.75 mg/mL) [33] immobilized implant group (the PDGF/Hepa/Ti group), the rhBMP-2 (0.75 mg/mL) immobilized implant group (BMP/Hepa/Ti group), and the rhPDGF-BB (0.75 mg/mL) plus rhBMP-2 (0.75 mg/mL) [34,35] immobilized implant group (PDGF/BMP/Hepa/Ti group). Eight implants were allocated to each group (a total of 40). To apply rhBMP-2/rhPDGF-BB coating, each implant was placed h in the protein solution for 12 (0.75 mg/mL for rhBMP-2, 0.75 mg/mL for rhPDGF-BB) up to its microthreads, and then freeze dried under sterile conditions (freeze dried at −40 ◦C, and then vacuum dried at ≤20 ◦C).

This study was carried out with the approval from the Ethics Committee on Animal Experimentation of Chun Nam University (CNU IACUC-TB-2010-10). Five three-year-old beagle dogs of weight 13–15 kg were used for this study. Animals were given two-weeks to acclimatize, fed a soft-dog food diet, and had free access to water.
