3.3.3. Gene Expressions

After 7 and 21 days of culture, the mRNA expression levels of OCN and OPN in cells grown on Ti disc or on Ti modified with rhPDGF-BB and/or rhBMP-2 were determined by real-time PCR (Figure 6). mRNA expression levels of OCN and OPN in cells cultured on BMP/Hepa/Ti or PDGF/BMP/Hepa/Ti were markedly higher than in those cultured on Ti alone at day 7. In addition, OCN and OPN expressions in cells cultivated on PDGF/Hepa/Ti were greater than in those cultivated on Ti alone at day 7, but not significantly so. On day 21, the expression levels of OCN and OPN in cells that are grown on Hepa/Ti immobilized with rhPDGF-BB and/or rhBMP-2 and Ti alone were significantly different, as were OCN and OPN expressions in cells cultivated on BMP/Hepa/Ti and PDGF/Hepa/Ti or PDGF/BMP/Hepa/Ti discs.

**Figure 6.** Real-time PCR analysis of the mRNA levels of (**a**) osteocalcin and (**b**) osteopontin in cells grown on Ti, PDGF/Hepa/Ti, BMP/Hepa/Ti, or PDGF/BMP/Hepa/Ti discs for 7 or 21 days (\* *p* < 0.05 and \*\* *p* < 0.01).

#### *3.4. In Vivo Animal Study*

#### 3.4.1. Clinical Findings

All of the experimental animals survived during the healing procedure, and there was no observation of infection or inflammation at surgical sites. Samples of 40 implants were collected without any issue for in vivo μCT and Histomorphometric analysis.
