Anti - Cytokine Activity Enhances Osteogenesis of Bioactive Implants.

In dental clinical practice, systemic steroids are often applied at the end of implant surgeries in order to reduce postsurgical inflammation (tissue swelling, etc.), and to reduce patient discomfort. However, the use of systemic steroids is associated with generalized catabolic effects and with a temporarily reduced immunological competence. We hypothesize that by applying locally anti-cytokine antibodies (anti-TNF- and anti-IL-1) together with a bioactive osteogenic implant at the time of the surgical intervention for the placement of a construct, we will be able to achieve the same beneficial effects as by use of systemic steroids, but are able avoid the generalized anti-anabolic effects and the reduced immunocompetence effects, associated with the systemic use of steroids. In an adult rat model, a collagen sponge, soaked with the osteogenic agent BMP-2 (bone morphogenetic protein-2), was used as an example for a bioactive implant material and was surgically placed subcutaneously. In the acute inflammatory phase after implantation (2 days after surgery) we investigated the local inflammatory tissue response, and 18 days postsurgically the efficiency of local osteogenesis (in order to assess possible anti-anabolic effects). We found that the negative control groups, treated postsurgically with systemic steroids, showed a significant suppression of both the inflammatory response as well as the osteogenetic activity, i.e. were associated with significant general anti-anabolic effects, even when steroids were used only at low dose level. The local anti-cytokine treatment, however, was able to significantly enhance new bone formation activity, i.e. the anabolic activity, over positive control values with BMP-2 only. However, the anti-cytokine treatment was unable to reduce the local inflammatory and swelling responses.