The aim of this study was to evaluate the effect of biofunctionalization with two TGF-β1 inhibitor peptides, P17 and P144, on osseointegration of CP-Ti dental implants. A total of 36 implants (VEGA, Klockner®) with 3.5 × 8 mm internal connection were used in this study, divided in three groups: (1) control group (n = 12), (2) implants which surfaces were biofunctionalized with P17 peptide inhibitor (n = 12), (3) implants with surfaces biofunctionalized by P144 peptide (n = 12). Three implants, one from each group, were inserted in both hemimandibles of 6 beagle dogs, 2 months after tooth extraction. Two animals were sacrificed at 2, 4 and 8 weeks post implant insertion, respectively. The samples were analyzed by Backscattering Scanning Electron Microscopy (BS-SEM) and histological analysis. Histomorphometric analysis of bone to implant contact (BIC), peri-implant bone fraction (BF) and interthread bone (IB) were carried out. Bone formation around implants measured by quantitative analysis, BS-SEM, was significantly higher in the P17-biofunctionalized implants, 4 and 8 weeks after the implantation. Histomorphometric analysis of BIC, BF and IB showed higher values in the P17-biofunctionalized group at initial stages of healing (2 weeks) and early osseointegration both at 4 and 8 weeks. For P144 biofunctionalized implants, the histomorphometric values obtained are also higher than control group. Accordingly, better results in the experimental groups were proven both by the quantitative and the qualitative analysis. Surface biofunctionalization with TGF-β1 inhibitor peptides, P17 and P144, resulted in better quantitative and qualitative parameters relative to implant osseointegration.