There are some special cases in implant preparation.For example, in some cases, the implant may be placed in the same session with tooth extraction.There should be no infection of the extracted tooth so that the implants can be placed in this way and adequate bone which allow the first stabilization of the implant should be available.The advantage of this is that shorten the duration of treatment.But most of cases , it is necessary to wait until the traction cavity heals within 2-3 months before implant placement.