Placing implants at the time of tooth removal could be the very best treatment decision for patient and doctor. However, I do understand that you may not feel comfortable with this idea.  Waiting four weeks should not be a problem and scar tissue is not a problem either. Typically four weeks is not enough time for significant bone loss to take place.  There is always the risk of an unforseen delay in implant placement for whatever reason.  In your case I would strongly consider a bone preservation procedure at the time of tooth removal if you feel your appointment plan could change or you dont want to risk unforseen needs to graft at the time of implant placement.   Because some areas of the bone remaining after a removal could be unexpectedly thinner or weaker, these areas could “disappear” shortly thereafter and make it difficult or in extreme cases impossible and even dangerous to proceed with implant placement without having to add more involved, more expensive grafting procedures and possibly delay the time of tooth replacement. Bone preservation can be accomplished with natural growth factors that can be obtained from your plasma in minutes where all you expirience is a small blood sample just like you would at your physicians office. This technique is known as PRGF. Other more traditional techniques involve the use of human or cow bone mineral.