A bone graft for immediate single implants is often needed. Most immediate implants are for single rooted teeth like your front and middle back teeth (premolars.) In my Burbank dental implant practice, this type of bone graft is common.
Most implants are round in shape. Most extraction sockets are oval or rectangular if they are molars. When I place an immediate implant into an extraction socket there may be a void. That void is caused by the different shape between the round implant and the larger, non-round extraction socket. See diagram below.
That void often needs to be grafted with bone so gum or soft tissue doesn't fill in instead.
This implies that the extraction was meticulously performed without losing your bone and that the walls of the socket are fully intact. Sometimes you cannot avoid some bone loss when a tooth is removed. Often the bone on the outside is missing which can mean that having an immediate same day implant unpredictable. Root canal teeth or teeth with advanced gum disease are often missing the walls of socket.
If the void is really small, no bone graft is needed as it will naturally fill with bone.
It is possible to have a bone graft, extraction, dental implant and a temporary crown on the implant all on the same day!
If I am replacing all your teeth on one arch as immediate implants, this type of bone graft can sometimes be avoided. This is because the bone loss caused by gum disease causes the oval sockets to become more round. The lower jaw is really good for immediate, same day, full implants.
Ramsey A. Amin, D.D.S.
Diplomate of the American Board of Oral Implantology /Implant Dentistry
Fellow of the American Academy of Implant Dentistry