Abstract Background: Bone morphogenetic proteins (BMPs) have shown considerable promise as a therapeutic agent to enhance periodontal regeneration although the optimal characterisitics of a suitable release system are not known.Aim: The aim of this study was to compare the effects of slow and fast degrading gelatin carriers on BMP‐2‐induced periodontal healing.Method: Recombinant human bone morphogenetic protein‐2 (rhBMP‐2) was incorporated into gelatin and subsequently differentially cross‐linked to produce slow and fast release carrier systems. Release kinetics were confirmed in vitro, by measuring release of 125I‐growth hormone from similar gelatin plugs. Effects of BMP were evaluated in surgically created rat periodontal fenestration defects which were processed for histology 10 days post‐operatively. The rats were divided into 4 groups and the control defects were treated with either slow or fast degrading gelatin (CONs or CONf respectively), whilst test groups were treated with 1.25 μg rhBMP‐2 in the slow or fast degrading gelatin (BMPs or BMPf respectively).Results: BMPf greatly increased bone formation compared with the control (CONf) (1.67±0.65 versus 0.34±0.11×10−4 m2), but no significant differences were observed with BMPs and CONs. In contrast, new cementum formation was significantly greater in the BMPs group compared with all other groups (p<0.05).Conclusion: Release kinetics of BMP may have important effects on the outcome of BMP‐induced periodontal regeneration. New bone formation may be affected by rapid‐release kinetics although further investigation is necessary to confirm this. In contrast, new cementum formation is promoted by slow release of BMP.