Background: Peri-implant tissues form a crucial but fragile seal between the oral environment, the bone and the implant surface. Enhancing the seal formed by the peri-implantsoft tissues at the titanium/connective tissue interface may be an important factor in implant survival. Additionally, enhancing soft tissue adherence to the implant surface when implants are placed in dehiscence type defects may mean that simultaneous osseous grafting procedures will not always be required. Objective: The aim of this study was to investigate the effect of implant surface modification with either platelet-derived growth factor (PDGF) or enamel matrix derivative (EMD) on the connective tissue attachment to moderately roughened titanium implants. Material and Methods: 18 moderately roughened titanium implants were subcutaneously implanted into 14 rats. 6 implants each were coated with PDGF and EMD immediately priorto implantation and 6 implants were left uncoated. The implants were retrieved with a sample of surrounding tissue at 4 and 8 weeks. The specimens were resin-embedded and sections viewed under confocal microscopy for collagen autofluorescence and prepared for qualitative and histomorphometric analysis under light microscopy. ANOVA and t-tests were used to compare the thickness of fibroblast encapsulation on the implant surface and the depth of connective tissue penetration onto the implant grooves. Results: Qualitative analysis under confocal and light microscopy showed encapsulation ofall implants by fibroblasts and good soft tissue integration at the end of 4 and 8 weeks. Coating of the implants with growth factors did not alter the orientation of fibroblasts and collagen fibres. Histomorphometric analysis demonstrated that the depth of connective tissue penetration into the implant grooves was significantly greater for the implants coated with PDGF at 4 weeks (ANOVA, P value 0.0014). The thickness of the fibroblast encapsulation onthe implant surface was significantly less for the implants coated with PDGF at 8 weeks (ANOVA, P value 0.0012). Conclusion: Good soft tissue integration can be achieved on a moderately roughenedtitanium implant surface. Coating the implant surface with rhPDGF-BB could increase the speed of soft tissue healing around an implant surface but this increased rate of healing with rhPDGFBB coating could also result in a less robust titanium/connective tissue interface.