Sometimes there is enough natural bone left to place the implants in a normal fashion without the addition of any extra bone.
Sometimes we are able to add bone and place the implants at the same time.
When there is very little natural bone to secure the implant, the necessary bone is added in the form of a graft which creates a new sinus floor. We let this heal about three months, then when the graft is mature we are able to place implants. A variety of graft materials can be used in these procedures.