The success of implantation depends on both the quality and the quantity of the bone found in the jaw.

A lot of times the amount of bone matter available is not enough to hold an artificial root made necessary by parodontitis, accidents or various types of disease.

The animation shows how bone recession sets in due to a lack of chewing pressure. Our body is very efficient - use it or lose it! After a while there is not enough bone matter left for an implant, the implant would stick out (as shown by the blinking light). Fortunately, it is possible to re-build bone – as shown here in onlay surgery. A chunk of bone is taken, for example from the end of the jaw, and transplanted somewhere else. This increases the size of the bone, which enables implantation.

Nowadays there are many surgical techniques which can be used to build up jaw bone, using bone from a patient’s own body, synthetic bone material or a bone expansion technique called traction.
Human bone heals best, while synthetic materials heal worst. With respect to human bone, it is possible to use either purified donor bones – or the patient’s own.
If bone is taken from the patient’s own body, the chunk of bone should not exceed a certain size, because otherwise it would recede. This is because the transplanted chunk of bone contains various types of cells. The moment that the chunk is removed, the cells it contains are cut off from the supply of nutrients. If a chunk is small enough, then soon after transplantation it is once again connected to the supply of nutrients by the process of diffusion. If the bone is too big, then the innermost cells cannot be reached by diffusion, and it takes days for new blood vessels to grow into the bone. The cells inside the block are left without nutrients for too long – and they die. The immune system reacts by removing the dead cells, which causes the bone to recede. This is why larger bone chunks are transplanted on the micro-vascular level, along with the vessels which are then connected to other vessels in the area. This ensures the supply of nutrients to the inside of the bone, the cells survive and the bone retains its size.

Micro-vascular transplantation is usually not necessary, smaller chunks of bone are enough. Nowadays there are expensive techniques for growing bone (both synthetic and natural) in laboratories using a patient’s own cells. This is supposed to speed up the transplantation process, but once the bone is removed from the optimum conditions of this „incubator“ – and transplanted into the patient, after a while the bone starts „melting away“ due to a lack of nutrients. This method is interesting and sounds very nice, but it is expensive and ineffective.

Horizontal build-up in a jaw bone which contains teeth – as is the case with patients having parodontitis – is not possible, since the rest of the teeth are in the way. Bones need blood to grow. A defect in the bone could be vertical, meaning that it is only missing in a few places, as shown here. The defect has 5 sides, four of which consist of bone with good circulation – which is ideal for growing replacement bone. One side, where the root is, is not that well supplied with blood – which is bad for the replacement material – and is also the ideal gateway for bacteria, bits of food and saliva, since the gums in this area do not close up well after an operation – which delays the healing process. Such isolated defects can be treated well using modern methods, but if there are horizontal defects in the bone – extending over the entire length of the jaw, then treatment is no longer possible because there is not enough well-circulated „surrounding bone“. It is therefore necessary to take the rest of the jaw and teeth into account before making a plan to build up bone in the jaw. More information on these surgical techniques can be found under the following links:

Sinus lift
Osteo-traction
Onlay surgery
Recession