Timing, positioning, and sequential staging in esthetic implant therapy: a four-dimensional perspective.

Many articles address the predictability of immediate implant placement into extraction sockets; however, there are only a few reports that mention the indications and limitations of this technique. The aim of this article is to re-examine specific indications for immediate implant placement and to clarify the timing or "fourth dimension" relative to extraction and implant placement. The expanded concept of four-dimensional implant treatment planning involves the new axis of time, which must be considered along with the traditional spatial or three-dimensional management of implant positioning.