It is important to achieve an adequate degree of stability in bone at the time of implant placement (primary stability). Many factors influence this goal, and implant length is a major factor. For example, placement into a fresh extraction socket, where immediate restoration of the implant is planned, will require a longer implant to engage the residua socket walls and bone beyond the socket than if an implant is placed in mature bone and left to heal submerged below the sutured gingiva.