Bone Grafting

Bone Grafting or Augmentation

When teeth are lost, the underlying bone (alveolar bone)is likely to resorb (shrink) both vertically and horizontally.

The alveolar bone supports the teeth and when it no longerreceives stimulation from forces on the teeth, it tends to resorb away.

Areas with teeth that have been missing for a longtime, and/or have been prosthetically replaced with removabledentures, will often have so much bone resorption thatthere is not enough remaining to be able to place implants ofadequate size.

Similarly, teeth that have been lost due to advanced periodontaldisease (gum disease), will often have experiencedso much bone loss that there is not enough bone remainingfor implants to be placed.

Bone defects from root canal infection,fractured teeth, trauma, or difficult tooth removal may also create a situation where bone needs to be augmented(replaced by means of grafting) for implant placement to beaccomplished.

Bone Grafting Materials

There are many types of bone graft material currently available and research promises more to come. Generally the gold standard of grafting materials is to use a patient’s own bone, harvesting it from nearby areas, sections of the patient’s lower jaw, or harvesting it from the knee or hip (both of which have readily accessible and large amounts of bone available).

Other commonly used types of bone are derived from cow bone that has been processed to remove protein and acts as a stimulus for the body to replace it with new bone.

Human cadaver (allograft) bone can also be used, as well as several forms of synthetics.

Socket Preservation

When teeth are extracted, especially when an implant is being planned to replace the tooth about to be lost it is common in implant dentistry to recommend the placement of bone grafts at the time of the tooth removal to help maintain the existing bone so that in the future an implant can be placed more predictably in abuntant bone and avoid the need for additional separate grafting procedures which will increase costs and complexity.

This can be worth considering even if the implant is not going to be placed for up to 5 years following extraction. If there has been destruction to parts of the bony walls of the tooth socket, a socket preservation may be required. This more extensive approach is taken to isolate the socket and “rebuild” the walls to appropriate height and width using a barrier membrane. During this procedure, the gums surrounding the socket are separated from the bone to expose the remaining bone and a sheet of material is placed under the gum. This material comes in many forms but is used to prevent gum cells from making their way into the socket. This enables the slower-moving bone cells to grow and fill out the socket to an adequate dimension to receive an implant.

 

Sinus Grafting

The maxillary sinuses are hollow, air-filled spaces in the bone above our upper back teeth between the teeth and the eye sockets, and are one of the five pairs of sinus cavities throughout our skull bones.

When the upper back teeth (usually molars and premolars) are lost, the sinus cavity located just above tends to expand and drop down into the jaw bone in the area of the missing teeth (pneumatization). Even if the teeth are still present, there is sometimes not enough height of bone between the sinus floor and the gum to allow adequately sized implants to be placed.

Sinus grafting allows the floor of the sinus cavity to be lifted up bone graft materials can be placed that will stimulate adequate growth of bone for implants to be placed

Sinus grafting can be done as a preliminary surgery to prepare the bone for implant placement or can be performed at the same time as the implant placement, if there is enough bone to stabilize the implants while they are healing.

 

Osteotome Sinus Lift

An alternative approach to increase the height of bone under your sinuses is an osteotome sinus lift. In this procedure, a small amount of bone is left under the sinus cavity floor in the site of an implant placement. Blunt instruments (osteotomes) are used to push up the bone that has been retained, along with the lining of the sinus cavity itself. This raises the floor of the sinus in the local area of the implant placement only, thereby enabling a longer implant to be placed of more adequate proportions, which in turn provides more stability and strength to receive the forces of chewing.

 

Ridge Augmentation Grafting

When there has been signifi cant loss of the volume of bone in a desirable area for implant placement, you may require a ridge augmentation procedure. This procedure rebuilds the “lost bone” which is necessary to proceed with implant placement. Ridge augmentation may be performed at the same time as implants are placed, or may be necessary as a preliminary surgery to graft suffi cient bone before the implant surgery

Please note that at the Ballarat Implant Centre Dr Johnston will be able to advise you on any bone grafting procedures that you may require but like all surgical procedures it can be advisable to seek a second opinion.