Purpose: One strategy to improve implant osseointegration is to control the quality of the bone reaction at the implant-bone tissue interface using an implant coated with biologically active substances. The purpose of this study was to investigate the effect of a tetra-cell adhesion molecule (T-CAM) coating composed of 4 cell-adhesion molecules-an arginine-glycine-aspartic acid (RGD) sequence, a proline-histidine-serine-arginine-asparagine (PHSRN) sequence, a tyrosine-histidine sequence (YH), and a glutamic acid-proline-aspartic acid-isoleucine-methionine (EPDIM)-on the rough-surfaced titanium implant on peri-implant bone formation in the rabbit femur with poor local bone conditions and minimal primary stability. Materials and Methods: Seven T-CAM-coated (blasted/T-CAM) and uncoated (blasted) implants with a rough surface (hydroxyapatite-blasted; Ra = 1.8 µm) were placed in slightly oversized beds of the metaphyses of the right and left femurs of 7 New Zealand White rabbits with light tactile pressure, and minimal primary stability was obtained. To evaluate the effects of T-CAM coating on the peri-implant bone healing response, histomorphometric analysis was performed 8 weeks after surgery. The 2 groups were compared using the Student t test, with a significance level of P .05. Results: Compared to uncoated blasted implants at 8 weeks of healing, the blasted/T-CAM implants showed a significantly greater amount of bone-implant contact (BIC; P .01) and new bone formation in the zones 0 to 100 µm and 0 to 500 µm lateral to the implant surface (P .05) in the medullary space. Conclusion: The T-CAM coating on the rough-surfaced titanium implants significantly enhanced peri-implant bone formation in rabbit femurs with poor local bone condition. (More than 50 references) Schlagwörter: cell adhesion molecule, dental implants, osseointegration, poor bone quality, rough surface, titanium