Regional acceleratory phenomenon (RAP)

Regional acceleratory phenomenon, or RAP, is a local response to a stimulus in which tissues form two to ten times more rapidly than the normal regeneration process. The duration and intensity of RAP are directly proportional to the kind and amount of stimulus and the site where it was produced. Each type of tissue has its own response to RAP as well as its own time period in which RAP is experienced. However, regardless of tissue type, RAP usually lasts approximately four months in humans though it can take up to two years to subside. While no new processes in tissue formation appear to occur during RAP, a significant decrease in the normal time required for healing takes place. The stimuli that can cause RAP include fractures, injuries, inflammation or inflammatory diseases, and infections. In dentistry, RAP can be stimulated by tooth extractions, implants, and periodontal flaps.